![Andrew Jeffery](/assets/img/avatar_default.png)
The registers for the bt-bmc device live under the Aspeed LPC controller. Devicetree bindings have recently been introduced for the LPC controller where the "host" portion of the LPC register space is described as a syscon device. Future devicetrees describing the bt-bmc device should nest its node under the appropriate "simple-mfd", "syscon" compatible node. This change allows the bt-bmc driver to function with both syscon and non-syscon- based devicetree descriptions by always using a regmap for register access, either retrieved from the parent syscon device or instantiated if none exists. Signed-off-by: Andrew Jeffery <andrew@aj.id.au> Reviewed-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Corey Minyard <cminyard@mvista.com>
544 lines
12 KiB
C
544 lines
12 KiB
C
/*
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* Copyright (c) 2015-2016, IBM Corporation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/atomic.h>
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#include <linux/bt-bmc.h>
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#include <linux/errno.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/mfd/syscon.h>
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#include <linux/miscdevice.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/poll.h>
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#include <linux/regmap.h>
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#include <linux/sched.h>
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#include <linux/timer.h>
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/*
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* This is a BMC device used to communicate to the host
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*/
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#define DEVICE_NAME "ipmi-bt-host"
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#define BT_IO_BASE 0xe4
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#define BT_IRQ 10
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#define BT_CR0 0x0
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#define BT_CR0_IO_BASE 16
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#define BT_CR0_IRQ 12
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#define BT_CR0_EN_CLR_SLV_RDP 0x8
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#define BT_CR0_EN_CLR_SLV_WRP 0x4
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#define BT_CR0_ENABLE_IBT 0x1
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#define BT_CR1 0x4
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#define BT_CR1_IRQ_H2B 0x01
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#define BT_CR1_IRQ_HBUSY 0x40
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#define BT_CR2 0x8
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#define BT_CR2_IRQ_H2B 0x01
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#define BT_CR2_IRQ_HBUSY 0x40
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#define BT_CR3 0xc
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#define BT_CTRL 0x10
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#define BT_CTRL_B_BUSY 0x80
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#define BT_CTRL_H_BUSY 0x40
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#define BT_CTRL_OEM0 0x20
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#define BT_CTRL_SMS_ATN 0x10
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#define BT_CTRL_B2H_ATN 0x08
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#define BT_CTRL_H2B_ATN 0x04
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#define BT_CTRL_CLR_RD_PTR 0x02
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#define BT_CTRL_CLR_WR_PTR 0x01
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#define BT_BMC2HOST 0x14
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#define BT_INTMASK 0x18
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#define BT_INTMASK_B2H_IRQEN 0x01
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#define BT_INTMASK_B2H_IRQ 0x02
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#define BT_INTMASK_BMC_HWRST 0x80
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#define BT_BMC_BUFFER_SIZE 256
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struct bt_bmc {
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struct device dev;
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struct miscdevice miscdev;
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struct regmap *map;
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int offset;
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int irq;
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wait_queue_head_t queue;
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struct timer_list poll_timer;
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struct mutex mutex;
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};
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static atomic_t open_count = ATOMIC_INIT(0);
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static const struct regmap_config bt_regmap_cfg = {
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.reg_bits = 32,
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.val_bits = 32,
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.reg_stride = 4,
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};
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static u8 bt_inb(struct bt_bmc *bt_bmc, int reg)
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{
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uint32_t val = 0;
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int rc;
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rc = regmap_read(bt_bmc->map, bt_bmc->offset + reg, &val);
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WARN(rc != 0, "regmap_read() failed: %d\n", rc);
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return rc == 0 ? (u8) val : 0;
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}
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static void bt_outb(struct bt_bmc *bt_bmc, u8 data, int reg)
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{
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int rc;
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rc = regmap_write(bt_bmc->map, bt_bmc->offset + reg, data);
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WARN(rc != 0, "regmap_write() failed: %d\n", rc);
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}
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static void clr_rd_ptr(struct bt_bmc *bt_bmc)
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{
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bt_outb(bt_bmc, BT_CTRL_CLR_RD_PTR, BT_CTRL);
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}
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static void clr_wr_ptr(struct bt_bmc *bt_bmc)
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{
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bt_outb(bt_bmc, BT_CTRL_CLR_WR_PTR, BT_CTRL);
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}
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static void clr_h2b_atn(struct bt_bmc *bt_bmc)
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{
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bt_outb(bt_bmc, BT_CTRL_H2B_ATN, BT_CTRL);
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}
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static void set_b_busy(struct bt_bmc *bt_bmc)
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{
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if (!(bt_inb(bt_bmc, BT_CTRL) & BT_CTRL_B_BUSY))
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bt_outb(bt_bmc, BT_CTRL_B_BUSY, BT_CTRL);
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}
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static void clr_b_busy(struct bt_bmc *bt_bmc)
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{
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if (bt_inb(bt_bmc, BT_CTRL) & BT_CTRL_B_BUSY)
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bt_outb(bt_bmc, BT_CTRL_B_BUSY, BT_CTRL);
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}
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static void set_b2h_atn(struct bt_bmc *bt_bmc)
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{
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bt_outb(bt_bmc, BT_CTRL_B2H_ATN, BT_CTRL);
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}
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static u8 bt_read(struct bt_bmc *bt_bmc)
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{
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return bt_inb(bt_bmc, BT_BMC2HOST);
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}
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static ssize_t bt_readn(struct bt_bmc *bt_bmc, u8 *buf, size_t n)
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{
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int i;
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for (i = 0; i < n; i++)
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buf[i] = bt_read(bt_bmc);
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return n;
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}
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static void bt_write(struct bt_bmc *bt_bmc, u8 c)
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{
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bt_outb(bt_bmc, c, BT_BMC2HOST);
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}
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static ssize_t bt_writen(struct bt_bmc *bt_bmc, u8 *buf, size_t n)
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{
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int i;
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for (i = 0; i < n; i++)
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bt_write(bt_bmc, buf[i]);
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return n;
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}
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static void set_sms_atn(struct bt_bmc *bt_bmc)
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{
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bt_outb(bt_bmc, BT_CTRL_SMS_ATN, BT_CTRL);
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}
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static struct bt_bmc *file_bt_bmc(struct file *file)
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{
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return container_of(file->private_data, struct bt_bmc, miscdev);
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}
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static int bt_bmc_open(struct inode *inode, struct file *file)
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{
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struct bt_bmc *bt_bmc = file_bt_bmc(file);
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if (atomic_inc_return(&open_count) == 1) {
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clr_b_busy(bt_bmc);
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return 0;
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}
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atomic_dec(&open_count);
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return -EBUSY;
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}
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/*
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* The BT (Block Transfer) interface means that entire messages are
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* buffered by the host before a notification is sent to the BMC that
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* there is data to be read. The first byte is the length and the
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* message data follows. The read operation just tries to capture the
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* whole before returning it to userspace.
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*
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* BT Message format :
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*
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* Byte 1 Byte 2 Byte 3 Byte 4 Byte 5:N
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* Length NetFn/LUN Seq Cmd Data
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*
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*/
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static ssize_t bt_bmc_read(struct file *file, char __user *buf,
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size_t count, loff_t *ppos)
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{
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struct bt_bmc *bt_bmc = file_bt_bmc(file);
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u8 len;
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int len_byte = 1;
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u8 kbuffer[BT_BMC_BUFFER_SIZE];
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ssize_t ret = 0;
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ssize_t nread;
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if (!access_ok(VERIFY_WRITE, buf, count))
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return -EFAULT;
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WARN_ON(*ppos);
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if (wait_event_interruptible(bt_bmc->queue,
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bt_inb(bt_bmc, BT_CTRL) & BT_CTRL_H2B_ATN))
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return -ERESTARTSYS;
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mutex_lock(&bt_bmc->mutex);
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if (unlikely(!(bt_inb(bt_bmc, BT_CTRL) & BT_CTRL_H2B_ATN))) {
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ret = -EIO;
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goto out_unlock;
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}
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set_b_busy(bt_bmc);
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clr_h2b_atn(bt_bmc);
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clr_rd_ptr(bt_bmc);
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/*
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* The BT frames start with the message length, which does not
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* include the length byte.
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*/
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kbuffer[0] = bt_read(bt_bmc);
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len = kbuffer[0];
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/* We pass the length back to userspace as well */
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if (len + 1 > count)
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len = count - 1;
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while (len) {
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nread = min_t(ssize_t, len, sizeof(kbuffer) - len_byte);
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bt_readn(bt_bmc, kbuffer + len_byte, nread);
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if (copy_to_user(buf, kbuffer, nread + len_byte)) {
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ret = -EFAULT;
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break;
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}
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len -= nread;
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buf += nread + len_byte;
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ret += nread + len_byte;
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len_byte = 0;
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}
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clr_b_busy(bt_bmc);
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out_unlock:
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mutex_unlock(&bt_bmc->mutex);
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return ret;
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}
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/*
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* BT Message response format :
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*
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* Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6:N
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* Length NetFn/LUN Seq Cmd Code Data
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*/
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static ssize_t bt_bmc_write(struct file *file, const char __user *buf,
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size_t count, loff_t *ppos)
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{
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struct bt_bmc *bt_bmc = file_bt_bmc(file);
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u8 kbuffer[BT_BMC_BUFFER_SIZE];
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ssize_t ret = 0;
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ssize_t nwritten;
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/*
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* send a minimum response size
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*/
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if (count < 5)
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return -EINVAL;
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if (!access_ok(VERIFY_READ, buf, count))
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return -EFAULT;
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WARN_ON(*ppos);
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/*
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* There's no interrupt for clearing bmc busy so we have to
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* poll
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*/
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if (wait_event_interruptible(bt_bmc->queue,
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!(bt_inb(bt_bmc, BT_CTRL) &
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(BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN))))
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return -ERESTARTSYS;
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mutex_lock(&bt_bmc->mutex);
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if (unlikely(bt_inb(bt_bmc, BT_CTRL) &
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(BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN))) {
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ret = -EIO;
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goto out_unlock;
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}
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clr_wr_ptr(bt_bmc);
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while (count) {
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nwritten = min_t(ssize_t, count, sizeof(kbuffer));
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if (copy_from_user(&kbuffer, buf, nwritten)) {
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ret = -EFAULT;
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break;
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}
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bt_writen(bt_bmc, kbuffer, nwritten);
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count -= nwritten;
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buf += nwritten;
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ret += nwritten;
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}
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set_b2h_atn(bt_bmc);
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out_unlock:
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mutex_unlock(&bt_bmc->mutex);
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return ret;
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}
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static long bt_bmc_ioctl(struct file *file, unsigned int cmd,
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unsigned long param)
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{
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struct bt_bmc *bt_bmc = file_bt_bmc(file);
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switch (cmd) {
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case BT_BMC_IOCTL_SMS_ATN:
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set_sms_atn(bt_bmc);
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return 0;
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}
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return -EINVAL;
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}
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static int bt_bmc_release(struct inode *inode, struct file *file)
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{
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struct bt_bmc *bt_bmc = file_bt_bmc(file);
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atomic_dec(&open_count);
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set_b_busy(bt_bmc);
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return 0;
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}
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static unsigned int bt_bmc_poll(struct file *file, poll_table *wait)
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{
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struct bt_bmc *bt_bmc = file_bt_bmc(file);
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unsigned int mask = 0;
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u8 ctrl;
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poll_wait(file, &bt_bmc->queue, wait);
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ctrl = bt_inb(bt_bmc, BT_CTRL);
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if (ctrl & BT_CTRL_H2B_ATN)
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mask |= POLLIN;
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if (!(ctrl & (BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN)))
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mask |= POLLOUT;
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return mask;
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}
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static const struct file_operations bt_bmc_fops = {
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.owner = THIS_MODULE,
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.open = bt_bmc_open,
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.read = bt_bmc_read,
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.write = bt_bmc_write,
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.release = bt_bmc_release,
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.poll = bt_bmc_poll,
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.unlocked_ioctl = bt_bmc_ioctl,
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};
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static void poll_timer(unsigned long data)
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{
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struct bt_bmc *bt_bmc = (void *)data;
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bt_bmc->poll_timer.expires += msecs_to_jiffies(500);
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wake_up(&bt_bmc->queue);
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add_timer(&bt_bmc->poll_timer);
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}
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static irqreturn_t bt_bmc_irq(int irq, void *arg)
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{
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struct bt_bmc *bt_bmc = arg;
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u32 reg;
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int rc;
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rc = regmap_read(bt_bmc->map, bt_bmc->offset + BT_CR2, ®);
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if (rc)
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return IRQ_NONE;
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reg &= BT_CR2_IRQ_H2B | BT_CR2_IRQ_HBUSY;
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if (!reg)
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return IRQ_NONE;
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/* ack pending IRQs */
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regmap_write(bt_bmc->map, bt_bmc->offset + BT_CR2, reg);
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wake_up(&bt_bmc->queue);
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return IRQ_HANDLED;
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}
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static int bt_bmc_config_irq(struct bt_bmc *bt_bmc,
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struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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int rc;
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bt_bmc->irq = platform_get_irq(pdev, 0);
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if (!bt_bmc->irq)
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return -ENODEV;
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rc = devm_request_irq(dev, bt_bmc->irq, bt_bmc_irq, IRQF_SHARED,
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DEVICE_NAME, bt_bmc);
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if (rc < 0) {
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dev_warn(dev, "Unable to request IRQ %d\n", bt_bmc->irq);
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bt_bmc->irq = 0;
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return rc;
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}
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/*
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* Configure IRQs on the bmc clearing the H2B and HBUSY bits;
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* H2B will be asserted when the bmc has data for us; HBUSY
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* will be cleared (along with B2H) when we can write the next
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* message to the BT buffer
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*/
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rc = regmap_update_bits(bt_bmc->map, bt_bmc->offset + BT_CR1,
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(BT_CR1_IRQ_H2B | BT_CR1_IRQ_HBUSY),
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(BT_CR1_IRQ_H2B | BT_CR1_IRQ_HBUSY));
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return rc;
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}
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static int bt_bmc_probe(struct platform_device *pdev)
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{
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struct bt_bmc *bt_bmc;
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struct device *dev;
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int rc;
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if (!pdev || !pdev->dev.of_node)
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return -ENODEV;
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dev = &pdev->dev;
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dev_info(dev, "Found bt bmc device\n");
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bt_bmc = devm_kzalloc(dev, sizeof(*bt_bmc), GFP_KERNEL);
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if (!bt_bmc)
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return -ENOMEM;
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dev_set_drvdata(&pdev->dev, bt_bmc);
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bt_bmc->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
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if (IS_ERR(bt_bmc->map)) {
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struct resource *res;
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void __iomem *base;
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/*
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* Assume it's not the MFD-based devicetree description, in
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* which case generate a regmap ourselves
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*/
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(base))
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return PTR_ERR(base);
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bt_bmc->map = devm_regmap_init_mmio(dev, base, &bt_regmap_cfg);
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bt_bmc->offset = 0;
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} else {
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rc = of_property_read_u32(dev->of_node, "reg", &bt_bmc->offset);
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if (rc)
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return rc;
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}
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mutex_init(&bt_bmc->mutex);
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init_waitqueue_head(&bt_bmc->queue);
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bt_bmc->miscdev.minor = MISC_DYNAMIC_MINOR,
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bt_bmc->miscdev.name = DEVICE_NAME,
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bt_bmc->miscdev.fops = &bt_bmc_fops,
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bt_bmc->miscdev.parent = dev;
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rc = misc_register(&bt_bmc->miscdev);
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if (rc) {
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dev_err(dev, "Unable to register misc device\n");
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return rc;
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}
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bt_bmc_config_irq(bt_bmc, pdev);
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if (bt_bmc->irq) {
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dev_info(dev, "Using IRQ %d\n", bt_bmc->irq);
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} else {
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dev_info(dev, "No IRQ; using timer\n");
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setup_timer(&bt_bmc->poll_timer, poll_timer,
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(unsigned long)bt_bmc);
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bt_bmc->poll_timer.expires = jiffies + msecs_to_jiffies(10);
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add_timer(&bt_bmc->poll_timer);
|
|
}
|
|
|
|
regmap_write(bt_bmc->map, bt_bmc->offset + BT_CR0,
|
|
(BT_IO_BASE << BT_CR0_IO_BASE) |
|
|
(BT_IRQ << BT_CR0_IRQ) |
|
|
BT_CR0_EN_CLR_SLV_RDP |
|
|
BT_CR0_EN_CLR_SLV_WRP |
|
|
BT_CR0_ENABLE_IBT);
|
|
|
|
clr_b_busy(bt_bmc);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bt_bmc_remove(struct platform_device *pdev)
|
|
{
|
|
struct bt_bmc *bt_bmc = dev_get_drvdata(&pdev->dev);
|
|
|
|
misc_deregister(&bt_bmc->miscdev);
|
|
if (!bt_bmc->irq)
|
|
del_timer_sync(&bt_bmc->poll_timer);
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id bt_bmc_match[] = {
|
|
{ .compatible = "aspeed,ast2400-ibt-bmc" },
|
|
{ },
|
|
};
|
|
|
|
static struct platform_driver bt_bmc_driver = {
|
|
.driver = {
|
|
.name = DEVICE_NAME,
|
|
.of_match_table = bt_bmc_match,
|
|
},
|
|
.probe = bt_bmc_probe,
|
|
.remove = bt_bmc_remove,
|
|
};
|
|
|
|
module_platform_driver(bt_bmc_driver);
|
|
|
|
MODULE_DEVICE_TABLE(of, bt_bmc_match);
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Alistair Popple <alistair@popple.id.au>");
|
|
MODULE_DESCRIPTION("Linux device interface to the IPMI BT interface");
|