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alistair23-linux/arch/mips/include/asm/cdmm.h

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MIPS: Add CDMM bus support Add MIPS Common Device Memory Map (CDMM) support in the form of a bus in the standard Linux device model. Each device attached via CDMM is discoverable via an 8-bit type identifier and may contain a number of blocks of memory mapped registers in the CDMM region. IRQs are expected to be handled separately. Due to the per-cpu (per-VPE for MT cores) nature of the CDMM devices, all the driver callbacks take place from workqueues which are run on the right CPU for the device in question, so that the driver doesn't need to be as concerned about which CPU it is running on. Callbacks also exist for when CPUs are taken offline, so that any per-CPU resources used by the driver can be disabled so they don't get forcefully migrated. CDMM devices are created as children of the CPU device they are attached to. Any existing CDMM configuration by the bootloader will be inherited, however platforms wishing to enable CDMM should implement the weak mips_cdmm_phys_base() function (see asm/cdmm.h) so that the bus driver knows where it should put the CDMM region in the physical address space if the bootloader hasn't already enabled it. A mips_cdmm_early_probe() function is also provided to allow early boot or particularly low level code to set up the CDMM region and probe for a specific device type, for example early console or KGDB IO drivers for the EJTAG Fast Debug Channel (FDC) CDMM device. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/9599/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-25 09:39:50 -06:00
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2014 Imagination Technologies Ltd.
*/
#ifndef __ASM_CDMM_H
#define __ASM_CDMM_H
#include <linux/device.h>
#include <linux/mod_devicetable.h>
/**
* struct mips_cdmm_device - Represents a single device on a CDMM bus.
* @dev: Driver model device object.
* @cpu: CPU which can access this device.
* @res: MMIO resource.
* @type: Device type identifier.
* @rev: Device revision number.
*/
struct mips_cdmm_device {
struct device dev;
unsigned int cpu;
struct resource res;
unsigned int type;
unsigned int rev;
};
/**
* struct mips_cdmm_driver - Represents a driver for a CDMM device.
* @drv: Driver model driver object.
* @probe Callback for probing newly discovered devices.
* @remove: Callback to remove the device.
* @shutdown: Callback on system shutdown.
* @cpu_down: Callback when the parent CPU is going down.
* Any CPU pinned threads/timers should be disabled.
* @cpu_up: Callback when the parent CPU is coming back up again.
* CPU pinned threads/timers can be restarted.
* @id_table: Table for CDMM IDs to match against.
*/
struct mips_cdmm_driver {
struct device_driver drv;
int (*probe)(struct mips_cdmm_device *);
int (*remove)(struct mips_cdmm_device *);
void (*shutdown)(struct mips_cdmm_device *);
int (*cpu_down)(struct mips_cdmm_device *);
int (*cpu_up)(struct mips_cdmm_device *);
const struct mips_cdmm_device_id *id_table;
};
/**
* mips_cdmm_phys_base() - Choose a physical base address for CDMM region.
*
* Picking a suitable physical address at which to map the CDMM region is
* platform specific, so this function can be defined by platform code to
MIPS: Add CDMM bus support Add MIPS Common Device Memory Map (CDMM) support in the form of a bus in the standard Linux device model. Each device attached via CDMM is discoverable via an 8-bit type identifier and may contain a number of blocks of memory mapped registers in the CDMM region. IRQs are expected to be handled separately. Due to the per-cpu (per-VPE for MT cores) nature of the CDMM devices, all the driver callbacks take place from workqueues which are run on the right CPU for the device in question, so that the driver doesn't need to be as concerned about which CPU it is running on. Callbacks also exist for when CPUs are taken offline, so that any per-CPU resources used by the driver can be disabled so they don't get forcefully migrated. CDMM devices are created as children of the CPU device they are attached to. Any existing CDMM configuration by the bootloader will be inherited, however platforms wishing to enable CDMM should implement the weak mips_cdmm_phys_base() function (see asm/cdmm.h) so that the bus driver knows where it should put the CDMM region in the physical address space if the bootloader hasn't already enabled it. A mips_cdmm_early_probe() function is also provided to allow early boot or particularly low level code to set up the CDMM region and probe for a specific device type, for example early console or KGDB IO drivers for the EJTAG Fast Debug Channel (FDC) CDMM device. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/9599/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-25 09:39:50 -06:00
* pick a suitable value if none is configured by the bootloader.
*
* This address must be 32kB aligned, and the region occupies a maximum of 32kB
* of physical address space which must not be used for anything else.
*
* Returns: Physical base address for CDMM region, or 0 on failure.
*/
phys_addr_t mips_cdmm_phys_base(void);
MIPS: Add CDMM bus support Add MIPS Common Device Memory Map (CDMM) support in the form of a bus in the standard Linux device model. Each device attached via CDMM is discoverable via an 8-bit type identifier and may contain a number of blocks of memory mapped registers in the CDMM region. IRQs are expected to be handled separately. Due to the per-cpu (per-VPE for MT cores) nature of the CDMM devices, all the driver callbacks take place from workqueues which are run on the right CPU for the device in question, so that the driver doesn't need to be as concerned about which CPU it is running on. Callbacks also exist for when CPUs are taken offline, so that any per-CPU resources used by the driver can be disabled so they don't get forcefully migrated. CDMM devices are created as children of the CPU device they are attached to. Any existing CDMM configuration by the bootloader will be inherited, however platforms wishing to enable CDMM should implement the weak mips_cdmm_phys_base() function (see asm/cdmm.h) so that the bus driver knows where it should put the CDMM region in the physical address space if the bootloader hasn't already enabled it. A mips_cdmm_early_probe() function is also provided to allow early boot or particularly low level code to set up the CDMM region and probe for a specific device type, for example early console or KGDB IO drivers for the EJTAG Fast Debug Channel (FDC) CDMM device. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/9599/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-25 09:39:50 -06:00
extern struct bus_type mips_cdmm_bustype;
void __iomem *mips_cdmm_early_probe(unsigned int dev_type);
#define to_mips_cdmm_device(d) container_of(d, struct mips_cdmm_device, dev)
#define mips_cdmm_get_drvdata(d) dev_get_drvdata(&d->dev)
#define mips_cdmm_set_drvdata(d, p) dev_set_drvdata(&d->dev, p)
int mips_cdmm_driver_register(struct mips_cdmm_driver *);
void mips_cdmm_driver_unregister(struct mips_cdmm_driver *);
/*
* module_mips_cdmm_driver() - Helper macro for drivers that don't do
* anything special in module init/exit. This eliminates a lot of
* boilerplate. Each module may only use this macro once, and
* calling it replaces module_init() and module_exit()
*/
#define module_mips_cdmm_driver(__mips_cdmm_driver) \
module_driver(__mips_cdmm_driver, mips_cdmm_driver_register, \
mips_cdmm_driver_unregister)
/*
* builtin_mips_cdmm_driver() - Helper macro for drivers that don't do anything
* special in init and have no exit. This eliminates some boilerplate. Each
* driver may only use this macro once, and calling it replaces device_initcall
* (or in some cases, the legacy __initcall). This is meant to be a direct
* parallel of module_mips_cdmm_driver() above but without the __exit stuff that
* is not used for builtin cases.
*/
#define builtin_mips_cdmm_driver(__mips_cdmm_driver) \
builtin_driver(__mips_cdmm_driver, mips_cdmm_driver_register)
/* drivers/tty/mips_ejtag_fdc.c */
#ifdef CONFIG_MIPS_EJTAG_FDC_EARLYCON
int setup_early_fdc_console(void);
#else
static inline int setup_early_fdc_console(void)
{
return -ENODEV;
}
#endif
MIPS: Add CDMM bus support Add MIPS Common Device Memory Map (CDMM) support in the form of a bus in the standard Linux device model. Each device attached via CDMM is discoverable via an 8-bit type identifier and may contain a number of blocks of memory mapped registers in the CDMM region. IRQs are expected to be handled separately. Due to the per-cpu (per-VPE for MT cores) nature of the CDMM devices, all the driver callbacks take place from workqueues which are run on the right CPU for the device in question, so that the driver doesn't need to be as concerned about which CPU it is running on. Callbacks also exist for when CPUs are taken offline, so that any per-CPU resources used by the driver can be disabled so they don't get forcefully migrated. CDMM devices are created as children of the CPU device they are attached to. Any existing CDMM configuration by the bootloader will be inherited, however platforms wishing to enable CDMM should implement the weak mips_cdmm_phys_base() function (see asm/cdmm.h) so that the bus driver knows where it should put the CDMM region in the physical address space if the bootloader hasn't already enabled it. A mips_cdmm_early_probe() function is also provided to allow early boot or particularly low level code to set up the CDMM region and probe for a specific device type, for example early console or KGDB IO drivers for the EJTAG Fast Debug Channel (FDC) CDMM device. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/9599/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-25 09:39:50 -06:00
#endif /* __ASM_CDMM_H */