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alistair23-linux/drivers/soc/aspeed/aspeed-lpc-ctrl.c

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-27 00:55:01 -06:00
// SPDX-License-Identifier: GPL-2.0-or-later
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
/*
* Copyright 2017 IBM Corporation
*/
misc: aspeed-lpc: Request and enable LPC clock The LPC device needs to ensure it's clock is enabled before it can do anything. In the past the clock was enabled and left running by u-boot, however Linux now has an upstream clock driver that disables unused clocks. Tested-by: Lei YU <mine260309@gmail.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-19 00:24:21 -07:00
#include <linux/clk.h>
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
#include <linux/mfd/syscon.h>
#include <linux/miscdevice.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/poll.h>
#include <linux/regmap.h>
#include <linux/aspeed-lpc-ctrl.h>
#define DEVICE_NAME "aspeed-lpc-ctrl"
misc: aspeed-lpc-ctrl: Enable FWH and A2H bridge cycles To date this driver has relied on prevous state from out of tree hacks and vendor u-boot trees in order to have the host be able to access data over the LPC bus. Now we explicitly enable the AHB to LPC bridge and FWH cycles from when the user first configures the address to map. We chose to do this then as before that time there is no way for the kernel to know where it is safe to point the LPC window. Tested-by: Lei YU <mine260309@gmail.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-19 00:24:22 -07:00
#define HICR5 0x0
#define HICR5_ENL2H BIT(8)
#define HICR5_ENFWH BIT(10)
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
#define HICR7 0x8
#define HICR8 0xc
struct aspeed_lpc_ctrl {
struct miscdevice miscdev;
struct regmap *regmap;
misc: aspeed-lpc: Request and enable LPC clock The LPC device needs to ensure it's clock is enabled before it can do anything. In the past the clock was enabled and left running by u-boot, however Linux now has an upstream clock driver that disables unused clocks. Tested-by: Lei YU <mine260309@gmail.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-19 00:24:21 -07:00
struct clk *clk;
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
phys_addr_t mem_base;
resource_size_t mem_size;
u32 pnor_size;
u32 pnor_base;
};
static struct aspeed_lpc_ctrl *file_aspeed_lpc_ctrl(struct file *file)
{
return container_of(file->private_data, struct aspeed_lpc_ctrl,
miscdev);
}
static int aspeed_lpc_ctrl_mmap(struct file *file, struct vm_area_struct *vma)
{
struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file);
unsigned long vsize = vma->vm_end - vma->vm_start;
pgprot_t prot = vma->vm_page_prot;
if (vma->vm_pgoff + vsize > lpc_ctrl->mem_base + lpc_ctrl->mem_size)
return -EINVAL;
/* ast2400/2500 AHB accesses are not cache coherent */
drivers/misc: Aspeed LPC control fix compile error and warning pgprot_dmachoerent() is not defined on every architecture. Having COMPILE_TEST set for the driver causes it to be compiled on architectures which do not have pgprot_dmachoerent(): drivers/misc/aspeed-lpc-ctrl.c: In function 'aspeed_lpc_ctrl_mmap': drivers/misc/aspeed-lpc-ctrl.c:51:9: error: implicit declaration of function 'pgprot_dmacoherent' [-Werror=implicit-function-declaration] prot = pgprot_dmacoherent(prot); There are two possible solutions: 1. Remove COMPILE_TEST to ensure the driver is only compiled on ARM 2. Use pgprot_noncached() instead of pgprot_dmachoerent() The first option results in less compile testing of the LPC control driver which is undesirable. The second option uses a function that is declared on all architectures and therefore should always build. Currently there is no practical difference between pgprot_noncached() and pgprot_dmachoerent() for the aspeed chips that this driver is compatible with. The reason for pgprot_dmachoerent() was that there may be chips made at some point in the future that could include hardware that pgprot_dmachoerent() could optimise for. As none of this hardware has even been announced there isn't really a need for pgprot_dmachoerent(). Using pgprot_noncached() is completely correct and optimal for all existing hardware on which the LPC control driver will run. This commit also addresses that phys_addr_t should be printed using %pap rather than %x: In file included from include/linux/miscdevice.h:6:0, from drivers/misc/aspeed-lpc-ctrl.c:11: drivers/misc/aspeed-lpc-ctrl.c: In function 'aspeed_lpc_ctrl_probe': drivers/misc/aspeed-lpc-ctrl.c:232:17: warning: format '%x' expects argument of type 'unsigned int', but argument 3 has type 'phys_addr_t {aka long long unsigned int}' [-Wformat=] dev_info(dev, "Loaded at 0x%08x (0x%08x)\n", Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-21 21:13:28 -06:00
prot = pgprot_noncached(prot);
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
if (remap_pfn_range(vma, vma->vm_start,
(lpc_ctrl->mem_base >> PAGE_SHIFT) + vma->vm_pgoff,
vsize, prot))
return -EAGAIN;
return 0;
}
static long aspeed_lpc_ctrl_ioctl(struct file *file, unsigned int cmd,
unsigned long param)
{
struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file);
soc: aspeed: lpc-ctrl: make parameter optional Making memory-region and flash as optional parameter in device tree if user needs to use these parameter through ioctl then need to define in devicetree. Signed-off-by: Vijay Khemka <vijaykhemka@fb.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au>
2019-05-30 14:36:51 -06:00
struct device *dev = file->private_data;
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
void __user *p = (void __user *)param;
struct aspeed_lpc_ctrl_mapping map;
u32 addr;
u32 size;
long rc;
if (copy_from_user(&map, p, sizeof(map)))
return -EFAULT;
if (map.flags != 0)
return -EINVAL;
switch (cmd) {
case ASPEED_LPC_CTRL_IOCTL_GET_SIZE:
/* The flash windows don't report their size */
if (map.window_type != ASPEED_LPC_CTRL_WINDOW_MEMORY)
return -EINVAL;
/* Support more than one window id in the future */
if (map.window_id != 0)
return -EINVAL;
soc: aspeed: lpc-ctrl: make parameter optional Making memory-region and flash as optional parameter in device tree if user needs to use these parameter through ioctl then need to define in devicetree. Signed-off-by: Vijay Khemka <vijaykhemka@fb.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au>
2019-05-30 14:36:51 -06:00
/* If memory-region is not described in device tree */
if (!lpc_ctrl->mem_size) {
dev_dbg(dev, "Didn't find reserved memory\n");
return -ENXIO;
}
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
map.size = lpc_ctrl->mem_size;
return copy_to_user(p, &map, sizeof(map)) ? -EFAULT : 0;
case ASPEED_LPC_CTRL_IOCTL_MAP:
/*
* The top half of HICR7 is the MSB of the BMC address of the
* mapping.
* The bottom half of HICR7 is the MSB of the HOST LPC
* firmware space address of the mapping.
*
* The 1 bits in the top of half of HICR8 represent the bits
* (in the requested address) that should be ignored and
* replaced with those from the top half of HICR7.
* The 1 bits in the bottom half of HICR8 represent the bits
* (in the requested address) that should be kept and pass
* into the BMC address space.
*/
/*
* It doesn't make sense to talk about a size or offset with
* low 16 bits set. Both HICR7 and HICR8 talk about the top 16
* bits of addresses and sizes.
*/
if ((map.size & 0x0000ffff) || (map.offset & 0x0000ffff))
return -EINVAL;
/*
* Because of the way the masks work in HICR8 offset has to
* be a multiple of size.
*/
if (map.offset & (map.size - 1))
return -EINVAL;
if (map.window_type == ASPEED_LPC_CTRL_WINDOW_FLASH) {
soc: aspeed: lpc-ctrl: make parameter optional Making memory-region and flash as optional parameter in device tree if user needs to use these parameter through ioctl then need to define in devicetree. Signed-off-by: Vijay Khemka <vijaykhemka@fb.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au>
2019-05-30 14:36:51 -06:00
if (!lpc_ctrl->pnor_size) {
dev_dbg(dev, "Didn't find host pnor flash\n");
return -ENXIO;
}
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
addr = lpc_ctrl->pnor_base;
size = lpc_ctrl->pnor_size;
} else if (map.window_type == ASPEED_LPC_CTRL_WINDOW_MEMORY) {
soc: aspeed: lpc-ctrl: make parameter optional Making memory-region and flash as optional parameter in device tree if user needs to use these parameter through ioctl then need to define in devicetree. Signed-off-by: Vijay Khemka <vijaykhemka@fb.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au>
2019-05-30 14:36:51 -06:00
/* If memory-region is not described in device tree */
if (!lpc_ctrl->mem_size) {
dev_dbg(dev, "Didn't find reserved memory\n");
return -ENXIO;
}
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
addr = lpc_ctrl->mem_base;
size = lpc_ctrl->mem_size;
} else {
return -EINVAL;
}
/* Check overflow first! */
if (map.offset + map.size < map.offset ||
map.offset + map.size > size)
return -EINVAL;
if (map.size == 0 || map.size > size)
return -EINVAL;
addr += map.offset;
/*
* addr (host lpc address) is safe regardless of values. This
* simply changes the address the host has to request on its
* side of the LPC bus. This cannot impact the hosts own
* memory space by surprise as LPC specific accessors are
* required. The only strange thing that could be done is
* setting the lower 16 bits but the shift takes care of that.
*/
rc = regmap_write(lpc_ctrl->regmap, HICR7,
(addr | (map.addr >> 16)));
if (rc)
return rc;
misc: aspeed-lpc-ctrl: Enable FWH and A2H bridge cycles To date this driver has relied on prevous state from out of tree hacks and vendor u-boot trees in order to have the host be able to access data over the LPC bus. Now we explicitly enable the AHB to LPC bridge and FWH cycles from when the user first configures the address to map. We chose to do this then as before that time there is no way for the kernel to know where it is safe to point the LPC window. Tested-by: Lei YU <mine260309@gmail.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-19 00:24:22 -07:00
rc = regmap_write(lpc_ctrl->regmap, HICR8,
(~(map.size - 1)) | ((map.size >> 16) - 1));
if (rc)
return rc;
/*
* Enable LPC FHW cycles. This is required for the host to
* access the regions specified.
*/
return regmap_update_bits(lpc_ctrl->regmap, HICR5,
HICR5_ENFWH | HICR5_ENL2H,
HICR5_ENFWH | HICR5_ENL2H);
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
}
return -EINVAL;
}
static const struct file_operations aspeed_lpc_ctrl_fops = {
.owner = THIS_MODULE,
.mmap = aspeed_lpc_ctrl_mmap,
.unlocked_ioctl = aspeed_lpc_ctrl_ioctl,
};
static int aspeed_lpc_ctrl_probe(struct platform_device *pdev)
{
struct aspeed_lpc_ctrl *lpc_ctrl;
struct device_node *node;
struct resource resm;
struct device *dev;
int rc;
dev = &pdev->dev;
lpc_ctrl = devm_kzalloc(dev, sizeof(*lpc_ctrl), GFP_KERNEL);
if (!lpc_ctrl)
return -ENOMEM;
soc: aspeed: lpc-ctrl: make parameter optional Making memory-region and flash as optional parameter in device tree if user needs to use these parameter through ioctl then need to define in devicetree. Signed-off-by: Vijay Khemka <vijaykhemka@fb.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au>
2019-05-30 14:36:51 -06:00
/* If flash is described in device tree then store */
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
node = of_parse_phandle(dev->of_node, "flash", 0);
if (!node) {
soc: aspeed: lpc-ctrl: make parameter optional Making memory-region and flash as optional parameter in device tree if user needs to use these parameter through ioctl then need to define in devicetree. Signed-off-by: Vijay Khemka <vijaykhemka@fb.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au>
2019-05-30 14:36:51 -06:00
dev_dbg(dev, "Didn't find host pnor flash node\n");
} else {
rc = of_address_to_resource(node, 1, &resm);
of_node_put(node);
if (rc) {
dev_err(dev, "Couldn't address to resource for flash\n");
return rc;
}
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
soc: aspeed: lpc-ctrl: Fix probe error handling gcc warns that a mising "flash" phandle node leads to undefined behavior later: drivers/soc/aspeed/aspeed-lpc-ctrl.c: In function 'aspeed_lpc_ctrl_probe': drivers/soc/aspeed/aspeed-lpc-ctrl.c:201:18: error: '*((void *)&resm+8)' may be used uninitialized in this function [-Werror=maybe-uninitialized] Only set the flash base and size if we find a phandle in the device tree. Reported-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Reviewed-by: Vijay Khemka <vijaykhemka@fb.com> Signed-off-by: Joel Stanley <joel@jms.id.au>
2019-06-20 03:17:38 -06:00
lpc_ctrl->pnor_size = resource_size(&resm);
lpc_ctrl->pnor_base = resm.start;
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
}
dev_set_drvdata(&pdev->dev, lpc_ctrl);
soc: aspeed: lpc-ctrl: make parameter optional Making memory-region and flash as optional parameter in device tree if user needs to use these parameter through ioctl then need to define in devicetree. Signed-off-by: Vijay Khemka <vijaykhemka@fb.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au>
2019-05-30 14:36:51 -06:00
/* If memory-region is described in device tree then store */
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
node = of_parse_phandle(dev->of_node, "memory-region", 0);
if (!node) {
soc: aspeed: lpc-ctrl: make parameter optional Making memory-region and flash as optional parameter in device tree if user needs to use these parameter through ioctl then need to define in devicetree. Signed-off-by: Vijay Khemka <vijaykhemka@fb.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au>
2019-05-30 14:36:51 -06:00
dev_dbg(dev, "Didn't find reserved memory\n");
} else {
rc = of_address_to_resource(node, 0, &resm);
of_node_put(node);
if (rc) {
dev_err(dev, "Couldn't address to resource for reserved memory\n");
return -ENXIO;
}
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
soc: aspeed: lpc-ctrl: make parameter optional Making memory-region and flash as optional parameter in device tree if user needs to use these parameter through ioctl then need to define in devicetree. Signed-off-by: Vijay Khemka <vijaykhemka@fb.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au>
2019-05-30 14:36:51 -06:00
lpc_ctrl->mem_size = resource_size(&resm);
lpc_ctrl->mem_base = resm.start;
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
}
lpc_ctrl->regmap = syscon_node_to_regmap(
pdev->dev.parent->of_node);
if (IS_ERR(lpc_ctrl->regmap)) {
dev_err(dev, "Couldn't get regmap\n");
return -ENODEV;
}
misc: aspeed-lpc: Request and enable LPC clock The LPC device needs to ensure it's clock is enabled before it can do anything. In the past the clock was enabled and left running by u-boot, however Linux now has an upstream clock driver that disables unused clocks. Tested-by: Lei YU <mine260309@gmail.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-19 00:24:21 -07:00
lpc_ctrl->clk = devm_clk_get(dev, NULL);
if (IS_ERR(lpc_ctrl->clk)) {
dev_err(dev, "couldn't get clock\n");
return PTR_ERR(lpc_ctrl->clk);
}
rc = clk_prepare_enable(lpc_ctrl->clk);
if (rc) {
dev_err(dev, "couldn't enable clock\n");
return rc;
}
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
lpc_ctrl->miscdev.minor = MISC_DYNAMIC_MINOR;
lpc_ctrl->miscdev.name = DEVICE_NAME;
lpc_ctrl->miscdev.fops = &aspeed_lpc_ctrl_fops;
lpc_ctrl->miscdev.parent = dev;
rc = misc_register(&lpc_ctrl->miscdev);
misc: aspeed-lpc: Request and enable LPC clock The LPC device needs to ensure it's clock is enabled before it can do anything. In the past the clock was enabled and left running by u-boot, however Linux now has an upstream clock driver that disables unused clocks. Tested-by: Lei YU <mine260309@gmail.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-19 00:24:21 -07:00
if (rc) {
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
dev_err(dev, "Unable to register device\n");
misc: aspeed-lpc: Request and enable LPC clock The LPC device needs to ensure it's clock is enabled before it can do anything. In the past the clock was enabled and left running by u-boot, however Linux now has an upstream clock driver that disables unused clocks. Tested-by: Lei YU <mine260309@gmail.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-19 00:24:21 -07:00
goto err;
}
return 0;
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
misc: aspeed-lpc: Request and enable LPC clock The LPC device needs to ensure it's clock is enabled before it can do anything. In the past the clock was enabled and left running by u-boot, however Linux now has an upstream clock driver that disables unused clocks. Tested-by: Lei YU <mine260309@gmail.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-19 00:24:21 -07:00
err:
clk_disable_unprepare(lpc_ctrl->clk);
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
return rc;
}
static int aspeed_lpc_ctrl_remove(struct platform_device *pdev)
{
struct aspeed_lpc_ctrl *lpc_ctrl = dev_get_drvdata(&pdev->dev);
misc_deregister(&lpc_ctrl->miscdev);
misc: aspeed-lpc: Request and enable LPC clock The LPC device needs to ensure it's clock is enabled before it can do anything. In the past the clock was enabled and left running by u-boot, however Linux now has an upstream clock driver that disables unused clocks. Tested-by: Lei YU <mine260309@gmail.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-19 00:24:21 -07:00
clk_disable_unprepare(lpc_ctrl->clk);
drivers/misc: Add Aspeed LPC control driver In order to manage server systems, there is typically another processor known as a BMC (Baseboard Management Controller) which is responsible for powering the server and other various elements, sometimes fans, often the system flash. The Aspeed BMC family which is what is used on OpenPOWER machines and a number of x86 as well is typically connected to the host via an LPC (Low Pin Count) bus (among others). The LPC bus is an ISA bus on steroids. It's generally used by the BMC chip to provide the host with access to the system flash (via MEM/FW cycles) that contains the BIOS or other host firmware along with a number of SuperIO-style IOs (via IO space) such as UARTs, IPMI controllers. On the BMC chip side, this is all configured via a bunch of registers whose content is related to a given policy of what devices are exposed at a per system level, which is system/vendor specific, so we don't want to bolt that into the BMC kernel. This started with a need to provide something nicer than /dev/mem for user space to configure these things. One important aspect of the configuration is how the MEM/FW space is exposed to the host (ie, the x86 or POWER). Some registers in that bridge can define a window remapping all or portion of the LPC MEM/FW space to a portion of the BMC internal bus, with no specific limits imposed in HW. I think it makes sense to ensure that this window is configured by a kernel driver that can apply some serious sanity checks on what it is configured to map. In practice, user space wants to control this by flipping the mapping between essentially two types of portions of the BMC address space: - The flash space. This is a region of the BMC MMIO space that more/less directly maps the system flash (at least for reads, writes are somewhat more complicated). - One (or more) reserved area(s) of the BMC physical memory. The latter is needed for a number of things, such as avoiding letting the host manipulate the innards of the BMC flash controller via some evil backdoor, we want to do flash updates by routing the window to a portion of memory (under control of a mailbox protocol via some separate set of registers) which the host can use to write new data in bulk and then request the BMC to flash it. There are other uses, such as allowing the host to boot from an in-memory flash image rather than the one in flash (very handy for continuous integration and test, the BMC can just download new images). It is important to note that due to the way the Aspeed chip lets the kernel configure the mapping between host LPC addresses and BMC ram addresses the offset within the window must be a multiple of size. Not doing so will fragment the accessible space rather than simply moving 'zero' upwards. This is caused by the nature of HICR8 being a mask and the way host LPC addresses are translated. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-16 20:28:49 -07:00
return 0;
}
static const struct of_device_id aspeed_lpc_ctrl_match[] = {
{ .compatible = "aspeed,ast2400-lpc-ctrl" },
{ .compatible = "aspeed,ast2500-lpc-ctrl" },
{ },
};
static struct platform_driver aspeed_lpc_ctrl_driver = {
.driver = {
.name = DEVICE_NAME,
.of_match_table = aspeed_lpc_ctrl_match,
},
.probe = aspeed_lpc_ctrl_probe,
.remove = aspeed_lpc_ctrl_remove,
};
module_platform_driver(aspeed_lpc_ctrl_driver);
MODULE_DEVICE_TABLE(of, aspeed_lpc_ctrl_match);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Cyril Bur <cyrilbur@gmail.com>");
MODULE_DESCRIPTION("Control for aspeed 2400/2500 LPC HOST to BMC mappings");