forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
528 lines
11 KiB
528 lines
11 KiB
// SPDX-License-Identifier: GPL-2.0+ |
|
/* |
|
* Copyright (c) 2015-2016, IBM Corporation. |
|
*/ |
|
|
|
#include <linux/atomic.h> |
|
#include <linux/bt-bmc.h> |
|
#include <linux/errno.h> |
|
#include <linux/interrupt.h> |
|
#include <linux/io.h> |
|
#include <linux/mfd/syscon.h> |
|
#include <linux/miscdevice.h> |
|
#include <linux/module.h> |
|
#include <linux/of.h> |
|
#include <linux/platform_device.h> |
|
#include <linux/poll.h> |
|
#include <linux/regmap.h> |
|
#include <linux/sched.h> |
|
#include <linux/timer.h> |
|
|
|
/* |
|
* This is a BMC device used to communicate to the host |
|
*/ |
|
#define DEVICE_NAME "ipmi-bt-host" |
|
|
|
#define BT_IO_BASE 0xe4 |
|
#define BT_IRQ 10 |
|
|
|
#define BT_CR0 0x0 |
|
#define BT_CR0_IO_BASE 16 |
|
#define BT_CR0_IRQ 12 |
|
#define BT_CR0_EN_CLR_SLV_RDP 0x8 |
|
#define BT_CR0_EN_CLR_SLV_WRP 0x4 |
|
#define BT_CR0_ENABLE_IBT 0x1 |
|
#define BT_CR1 0x4 |
|
#define BT_CR1_IRQ_H2B 0x01 |
|
#define BT_CR1_IRQ_HBUSY 0x40 |
|
#define BT_CR2 0x8 |
|
#define BT_CR2_IRQ_H2B 0x01 |
|
#define BT_CR2_IRQ_HBUSY 0x40 |
|
#define BT_CR3 0xc |
|
#define BT_CTRL 0x10 |
|
#define BT_CTRL_B_BUSY 0x80 |
|
#define BT_CTRL_H_BUSY 0x40 |
|
#define BT_CTRL_OEM0 0x20 |
|
#define BT_CTRL_SMS_ATN 0x10 |
|
#define BT_CTRL_B2H_ATN 0x08 |
|
#define BT_CTRL_H2B_ATN 0x04 |
|
#define BT_CTRL_CLR_RD_PTR 0x02 |
|
#define BT_CTRL_CLR_WR_PTR 0x01 |
|
#define BT_BMC2HOST 0x14 |
|
#define BT_INTMASK 0x18 |
|
#define BT_INTMASK_B2H_IRQEN 0x01 |
|
#define BT_INTMASK_B2H_IRQ 0x02 |
|
#define BT_INTMASK_BMC_HWRST 0x80 |
|
|
|
#define BT_BMC_BUFFER_SIZE 256 |
|
|
|
struct bt_bmc { |
|
struct device dev; |
|
struct miscdevice miscdev; |
|
struct regmap *map; |
|
int offset; |
|
int irq; |
|
wait_queue_head_t queue; |
|
struct timer_list poll_timer; |
|
struct mutex mutex; |
|
}; |
|
|
|
static atomic_t open_count = ATOMIC_INIT(0); |
|
|
|
static const struct regmap_config bt_regmap_cfg = { |
|
.reg_bits = 32, |
|
.val_bits = 32, |
|
.reg_stride = 4, |
|
}; |
|
|
|
static u8 bt_inb(struct bt_bmc *bt_bmc, int reg) |
|
{ |
|
uint32_t val = 0; |
|
int rc; |
|
|
|
rc = regmap_read(bt_bmc->map, bt_bmc->offset + reg, &val); |
|
WARN(rc != 0, "regmap_read() failed: %d\n", rc); |
|
|
|
return rc == 0 ? (u8) val : 0; |
|
} |
|
|
|
static void bt_outb(struct bt_bmc *bt_bmc, u8 data, int reg) |
|
{ |
|
int rc; |
|
|
|
rc = regmap_write(bt_bmc->map, bt_bmc->offset + reg, data); |
|
WARN(rc != 0, "regmap_write() failed: %d\n", rc); |
|
} |
|
|
|
static void clr_rd_ptr(struct bt_bmc *bt_bmc) |
|
{ |
|
bt_outb(bt_bmc, BT_CTRL_CLR_RD_PTR, BT_CTRL); |
|
} |
|
|
|
static void clr_wr_ptr(struct bt_bmc *bt_bmc) |
|
{ |
|
bt_outb(bt_bmc, BT_CTRL_CLR_WR_PTR, BT_CTRL); |
|
} |
|
|
|
static void clr_h2b_atn(struct bt_bmc *bt_bmc) |
|
{ |
|
bt_outb(bt_bmc, BT_CTRL_H2B_ATN, BT_CTRL); |
|
} |
|
|
|
static void set_b_busy(struct bt_bmc *bt_bmc) |
|
{ |
|
if (!(bt_inb(bt_bmc, BT_CTRL) & BT_CTRL_B_BUSY)) |
|
bt_outb(bt_bmc, BT_CTRL_B_BUSY, BT_CTRL); |
|
} |
|
|
|
static void clr_b_busy(struct bt_bmc *bt_bmc) |
|
{ |
|
if (bt_inb(bt_bmc, BT_CTRL) & BT_CTRL_B_BUSY) |
|
bt_outb(bt_bmc, BT_CTRL_B_BUSY, BT_CTRL); |
|
} |
|
|
|
static void set_b2h_atn(struct bt_bmc *bt_bmc) |
|
{ |
|
bt_outb(bt_bmc, BT_CTRL_B2H_ATN, BT_CTRL); |
|
} |
|
|
|
static u8 bt_read(struct bt_bmc *bt_bmc) |
|
{ |
|
return bt_inb(bt_bmc, BT_BMC2HOST); |
|
} |
|
|
|
static ssize_t bt_readn(struct bt_bmc *bt_bmc, u8 *buf, size_t n) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < n; i++) |
|
buf[i] = bt_read(bt_bmc); |
|
return n; |
|
} |
|
|
|
static void bt_write(struct bt_bmc *bt_bmc, u8 c) |
|
{ |
|
bt_outb(bt_bmc, c, BT_BMC2HOST); |
|
} |
|
|
|
static ssize_t bt_writen(struct bt_bmc *bt_bmc, u8 *buf, size_t n) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < n; i++) |
|
bt_write(bt_bmc, buf[i]); |
|
return n; |
|
} |
|
|
|
static void set_sms_atn(struct bt_bmc *bt_bmc) |
|
{ |
|
bt_outb(bt_bmc, BT_CTRL_SMS_ATN, BT_CTRL); |
|
} |
|
|
|
static struct bt_bmc *file_bt_bmc(struct file *file) |
|
{ |
|
return container_of(file->private_data, struct bt_bmc, miscdev); |
|
} |
|
|
|
static int bt_bmc_open(struct inode *inode, struct file *file) |
|
{ |
|
struct bt_bmc *bt_bmc = file_bt_bmc(file); |
|
|
|
if (atomic_inc_return(&open_count) == 1) { |
|
clr_b_busy(bt_bmc); |
|
return 0; |
|
} |
|
|
|
atomic_dec(&open_count); |
|
return -EBUSY; |
|
} |
|
|
|
/* |
|
* The BT (Block Transfer) interface means that entire messages are |
|
* buffered by the host before a notification is sent to the BMC that |
|
* there is data to be read. The first byte is the length and the |
|
* message data follows. The read operation just tries to capture the |
|
* whole before returning it to userspace. |
|
* |
|
* BT Message format : |
|
* |
|
* Byte 1 Byte 2 Byte 3 Byte 4 Byte 5:N |
|
* Length NetFn/LUN Seq Cmd Data |
|
* |
|
*/ |
|
static ssize_t bt_bmc_read(struct file *file, char __user *buf, |
|
size_t count, loff_t *ppos) |
|
{ |
|
struct bt_bmc *bt_bmc = file_bt_bmc(file); |
|
u8 len; |
|
int len_byte = 1; |
|
u8 kbuffer[BT_BMC_BUFFER_SIZE]; |
|
ssize_t ret = 0; |
|
ssize_t nread; |
|
|
|
WARN_ON(*ppos); |
|
|
|
if (wait_event_interruptible(bt_bmc->queue, |
|
bt_inb(bt_bmc, BT_CTRL) & BT_CTRL_H2B_ATN)) |
|
return -ERESTARTSYS; |
|
|
|
mutex_lock(&bt_bmc->mutex); |
|
|
|
if (unlikely(!(bt_inb(bt_bmc, BT_CTRL) & BT_CTRL_H2B_ATN))) { |
|
ret = -EIO; |
|
goto out_unlock; |
|
} |
|
|
|
set_b_busy(bt_bmc); |
|
clr_h2b_atn(bt_bmc); |
|
clr_rd_ptr(bt_bmc); |
|
|
|
/* |
|
* The BT frames start with the message length, which does not |
|
* include the length byte. |
|
*/ |
|
kbuffer[0] = bt_read(bt_bmc); |
|
len = kbuffer[0]; |
|
|
|
/* We pass the length back to userspace as well */ |
|
if (len + 1 > count) |
|
len = count - 1; |
|
|
|
while (len) { |
|
nread = min_t(ssize_t, len, sizeof(kbuffer) - len_byte); |
|
|
|
bt_readn(bt_bmc, kbuffer + len_byte, nread); |
|
|
|
if (copy_to_user(buf, kbuffer, nread + len_byte)) { |
|
ret = -EFAULT; |
|
break; |
|
} |
|
len -= nread; |
|
buf += nread + len_byte; |
|
ret += nread + len_byte; |
|
len_byte = 0; |
|
} |
|
|
|
clr_b_busy(bt_bmc); |
|
|
|
out_unlock: |
|
mutex_unlock(&bt_bmc->mutex); |
|
return ret; |
|
} |
|
|
|
/* |
|
* BT Message response format : |
|
* |
|
* Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6:N |
|
* Length NetFn/LUN Seq Cmd Code Data |
|
*/ |
|
static ssize_t bt_bmc_write(struct file *file, const char __user *buf, |
|
size_t count, loff_t *ppos) |
|
{ |
|
struct bt_bmc *bt_bmc = file_bt_bmc(file); |
|
u8 kbuffer[BT_BMC_BUFFER_SIZE]; |
|
ssize_t ret = 0; |
|
ssize_t nwritten; |
|
|
|
/* |
|
* send a minimum response size |
|
*/ |
|
if (count < 5) |
|
return -EINVAL; |
|
|
|
WARN_ON(*ppos); |
|
|
|
/* |
|
* There's no interrupt for clearing bmc busy so we have to |
|
* poll |
|
*/ |
|
if (wait_event_interruptible(bt_bmc->queue, |
|
!(bt_inb(bt_bmc, BT_CTRL) & |
|
(BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN)))) |
|
return -ERESTARTSYS; |
|
|
|
mutex_lock(&bt_bmc->mutex); |
|
|
|
if (unlikely(bt_inb(bt_bmc, BT_CTRL) & |
|
(BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN))) { |
|
ret = -EIO; |
|
goto out_unlock; |
|
} |
|
|
|
clr_wr_ptr(bt_bmc); |
|
|
|
while (count) { |
|
nwritten = min_t(ssize_t, count, sizeof(kbuffer)); |
|
if (copy_from_user(&kbuffer, buf, nwritten)) { |
|
ret = -EFAULT; |
|
break; |
|
} |
|
|
|
bt_writen(bt_bmc, kbuffer, nwritten); |
|
|
|
count -= nwritten; |
|
buf += nwritten; |
|
ret += nwritten; |
|
} |
|
|
|
set_b2h_atn(bt_bmc); |
|
|
|
out_unlock: |
|
mutex_unlock(&bt_bmc->mutex); |
|
return ret; |
|
} |
|
|
|
static long bt_bmc_ioctl(struct file *file, unsigned int cmd, |
|
unsigned long param) |
|
{ |
|
struct bt_bmc *bt_bmc = file_bt_bmc(file); |
|
|
|
switch (cmd) { |
|
case BT_BMC_IOCTL_SMS_ATN: |
|
set_sms_atn(bt_bmc); |
|
return 0; |
|
} |
|
return -EINVAL; |
|
} |
|
|
|
static int bt_bmc_release(struct inode *inode, struct file *file) |
|
{ |
|
struct bt_bmc *bt_bmc = file_bt_bmc(file); |
|
|
|
atomic_dec(&open_count); |
|
set_b_busy(bt_bmc); |
|
return 0; |
|
} |
|
|
|
static __poll_t bt_bmc_poll(struct file *file, poll_table *wait) |
|
{ |
|
struct bt_bmc *bt_bmc = file_bt_bmc(file); |
|
__poll_t mask = 0; |
|
u8 ctrl; |
|
|
|
poll_wait(file, &bt_bmc->queue, wait); |
|
|
|
ctrl = bt_inb(bt_bmc, BT_CTRL); |
|
|
|
if (ctrl & BT_CTRL_H2B_ATN) |
|
mask |= EPOLLIN; |
|
|
|
if (!(ctrl & (BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN))) |
|
mask |= EPOLLOUT; |
|
|
|
return mask; |
|
} |
|
|
|
static const struct file_operations bt_bmc_fops = { |
|
.owner = THIS_MODULE, |
|
.open = bt_bmc_open, |
|
.read = bt_bmc_read, |
|
.write = bt_bmc_write, |
|
.release = bt_bmc_release, |
|
.poll = bt_bmc_poll, |
|
.unlocked_ioctl = bt_bmc_ioctl, |
|
}; |
|
|
|
static void poll_timer(struct timer_list *t) |
|
{ |
|
struct bt_bmc *bt_bmc = from_timer(bt_bmc, t, poll_timer); |
|
|
|
bt_bmc->poll_timer.expires += msecs_to_jiffies(500); |
|
wake_up(&bt_bmc->queue); |
|
add_timer(&bt_bmc->poll_timer); |
|
} |
|
|
|
static irqreturn_t bt_bmc_irq(int irq, void *arg) |
|
{ |
|
struct bt_bmc *bt_bmc = arg; |
|
u32 reg; |
|
int rc; |
|
|
|
rc = regmap_read(bt_bmc->map, bt_bmc->offset + BT_CR2, ®); |
|
if (rc) |
|
return IRQ_NONE; |
|
|
|
reg &= BT_CR2_IRQ_H2B | BT_CR2_IRQ_HBUSY; |
|
if (!reg) |
|
return IRQ_NONE; |
|
|
|
/* ack pending IRQs */ |
|
regmap_write(bt_bmc->map, bt_bmc->offset + BT_CR2, reg); |
|
|
|
wake_up(&bt_bmc->queue); |
|
return IRQ_HANDLED; |
|
} |
|
|
|
static int bt_bmc_config_irq(struct bt_bmc *bt_bmc, |
|
struct platform_device *pdev) |
|
{ |
|
struct device *dev = &pdev->dev; |
|
int rc; |
|
|
|
bt_bmc->irq = platform_get_irq_optional(pdev, 0); |
|
if (bt_bmc->irq < 0) |
|
return bt_bmc->irq; |
|
|
|
rc = devm_request_irq(dev, bt_bmc->irq, bt_bmc_irq, IRQF_SHARED, |
|
DEVICE_NAME, bt_bmc); |
|
if (rc < 0) { |
|
dev_warn(dev, "Unable to request IRQ %d\n", bt_bmc->irq); |
|
bt_bmc->irq = rc; |
|
return rc; |
|
} |
|
|
|
/* |
|
* Configure IRQs on the bmc clearing the H2B and HBUSY bits; |
|
* H2B will be asserted when the bmc has data for us; HBUSY |
|
* will be cleared (along with B2H) when we can write the next |
|
* message to the BT buffer |
|
*/ |
|
rc = regmap_update_bits(bt_bmc->map, bt_bmc->offset + BT_CR1, |
|
(BT_CR1_IRQ_H2B | BT_CR1_IRQ_HBUSY), |
|
(BT_CR1_IRQ_H2B | BT_CR1_IRQ_HBUSY)); |
|
|
|
return rc; |
|
} |
|
|
|
static int bt_bmc_probe(struct platform_device *pdev) |
|
{ |
|
struct bt_bmc *bt_bmc; |
|
struct device *dev; |
|
int rc; |
|
|
|
dev = &pdev->dev; |
|
dev_info(dev, "Found bt bmc device\n"); |
|
|
|
bt_bmc = devm_kzalloc(dev, sizeof(*bt_bmc), GFP_KERNEL); |
|
if (!bt_bmc) |
|
return -ENOMEM; |
|
|
|
dev_set_drvdata(&pdev->dev, bt_bmc); |
|
|
|
bt_bmc->map = syscon_node_to_regmap(pdev->dev.parent->of_node); |
|
if (IS_ERR(bt_bmc->map)) { |
|
void __iomem *base; |
|
|
|
/* |
|
* Assume it's not the MFD-based devicetree description, in |
|
* which case generate a regmap ourselves |
|
*/ |
|
base = devm_platform_ioremap_resource(pdev, 0); |
|
if (IS_ERR(base)) |
|
return PTR_ERR(base); |
|
|
|
bt_bmc->map = devm_regmap_init_mmio(dev, base, &bt_regmap_cfg); |
|
bt_bmc->offset = 0; |
|
} else { |
|
rc = of_property_read_u32(dev->of_node, "reg", &bt_bmc->offset); |
|
if (rc) |
|
return rc; |
|
} |
|
|
|
mutex_init(&bt_bmc->mutex); |
|
init_waitqueue_head(&bt_bmc->queue); |
|
|
|
bt_bmc->miscdev.minor = MISC_DYNAMIC_MINOR; |
|
bt_bmc->miscdev.name = DEVICE_NAME; |
|
bt_bmc->miscdev.fops = &bt_bmc_fops; |
|
bt_bmc->miscdev.parent = dev; |
|
rc = misc_register(&bt_bmc->miscdev); |
|
if (rc) { |
|
dev_err(dev, "Unable to register misc device\n"); |
|
return rc; |
|
} |
|
|
|
bt_bmc_config_irq(bt_bmc, pdev); |
|
|
|
if (bt_bmc->irq >= 0) { |
|
dev_info(dev, "Using IRQ %d\n", bt_bmc->irq); |
|
} else { |
|
dev_info(dev, "No IRQ; using timer\n"); |
|
timer_setup(&bt_bmc->poll_timer, poll_timer, 0); |
|
bt_bmc->poll_timer.expires = jiffies + msecs_to_jiffies(10); |
|
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 < 0) |
|
del_timer_sync(&bt_bmc->poll_timer); |
|
return 0; |
|
} |
|
|
|
static const struct of_device_id bt_bmc_match[] = { |
|
{ .compatible = "aspeed,ast2400-ibt-bmc" }, |
|
{ .compatible = "aspeed,ast2500-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 <[email protected]>"); |
|
MODULE_DESCRIPTION("Linux device interface to the IPMI BT interface");
|
|
|