linux/drivers/spi/spi-sprd-adi.c
Baolin Wang ac17750120
spi: sprd: Add the support of restarting the system
On Spreadtrum platform, we use one PMIC watchdog to reset the whole system
with loading one suitable timeout value (usually 50ms) for the watchdog.

In theory, we should implement the restart function in drivers/power/reset
subsystem to access the PMIC watchdog with regmap. When restart the system,
other cores will be stopped by IPI, but if other cores were accessing PMIC
with holding the regmap mutex lock, that will cause dead-lock issue if we
try to access the PMIC watchdog with regmap to restart the whole system.
Thus we can implement the restart function in ADI driver to avoid this
issue.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-03-21 09:55:19 +08:00

537 lines
14 KiB
C

/*
* Copyright (C) 2017 Spreadtrum Communications Inc.
*
* SPDX-License-Identifier: GPL-2.0
*/
#include <linux/delay.h>
#include <linux/hwspinlock.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/spi/spi.h>
#include <linux/sizes.h>
/* Registers definitions for ADI controller */
#define REG_ADI_CTRL0 0x4
#define REG_ADI_CHN_PRIL 0x8
#define REG_ADI_CHN_PRIH 0xc
#define REG_ADI_INT_EN 0x10
#define REG_ADI_INT_RAW 0x14
#define REG_ADI_INT_MASK 0x18
#define REG_ADI_INT_CLR 0x1c
#define REG_ADI_GSSI_CFG0 0x20
#define REG_ADI_GSSI_CFG1 0x24
#define REG_ADI_RD_CMD 0x28
#define REG_ADI_RD_DATA 0x2c
#define REG_ADI_ARM_FIFO_STS 0x30
#define REG_ADI_STS 0x34
#define REG_ADI_EVT_FIFO_STS 0x38
#define REG_ADI_ARM_CMD_STS 0x3c
#define REG_ADI_CHN_EN 0x40
#define REG_ADI_CHN_ADDR(id) (0x44 + (id - 2) * 4)
#define REG_ADI_CHN_EN1 0x20c
/* Bits definitions for register REG_ADI_GSSI_CFG0 */
#define BIT_CLK_ALL_ON BIT(30)
/* Bits definitions for register REG_ADI_RD_DATA */
#define BIT_RD_CMD_BUSY BIT(31)
#define RD_ADDR_SHIFT 16
#define RD_VALUE_MASK GENMASK(15, 0)
#define RD_ADDR_MASK GENMASK(30, 16)
/* Bits definitions for register REG_ADI_ARM_FIFO_STS */
#define BIT_FIFO_FULL BIT(11)
#define BIT_FIFO_EMPTY BIT(10)
/*
* ADI slave devices include RTC, ADC, regulator, charger, thermal and so on.
* The slave devices address offset is always 0x8000 and size is 4K.
*/
#define ADI_SLAVE_ADDR_SIZE SZ_4K
#define ADI_SLAVE_OFFSET 0x8000
/* Timeout (ms) for the trylock of hardware spinlocks */
#define ADI_HWSPINLOCK_TIMEOUT 5000
/*
* ADI controller has 50 channels including 2 software channels
* and 48 hardware channels.
*/
#define ADI_HW_CHNS 50
#define ADI_FIFO_DRAIN_TIMEOUT 1000
#define ADI_READ_TIMEOUT 2000
#define REG_ADDR_LOW_MASK GENMASK(11, 0)
/* Registers definitions for PMIC watchdog controller */
#define REG_WDG_LOAD_LOW 0x80
#define REG_WDG_LOAD_HIGH 0x84
#define REG_WDG_CTRL 0x88
#define REG_WDG_LOCK 0xa0
/* Bits definitions for register REG_WDG_CTRL */
#define BIT_WDG_RUN BIT(1)
#define BIT_WDG_RST BIT(3)
/* Registers definitions for PMIC */
#define PMIC_RST_STATUS 0xee8
#define PMIC_MODULE_EN 0xc08
#define PMIC_CLK_EN 0xc18
#define BIT_WDG_EN BIT(2)
/* Definition of PMIC reset status register */
#define HWRST_STATUS_RECOVERY 0x20
#define HWRST_STATUS_NORMAL 0x40
#define HWRST_STATUS_ALARM 0x50
#define HWRST_STATUS_SLEEP 0x60
#define HWRST_STATUS_FASTBOOT 0x30
#define HWRST_STATUS_SPECIAL 0x70
#define HWRST_STATUS_PANIC 0x80
#define HWRST_STATUS_CFTREBOOT 0x90
#define HWRST_STATUS_AUTODLOADER 0xa0
#define HWRST_STATUS_IQMODE 0xb0
#define HWRST_STATUS_SPRDISK 0xc0
/* Use default timeout 50 ms that converts to watchdog values */
#define WDG_LOAD_VAL ((50 * 1000) / 32768)
#define WDG_LOAD_MASK GENMASK(15, 0)
#define WDG_UNLOCK_KEY 0xe551
struct sprd_adi {
struct spi_controller *ctlr;
struct device *dev;
void __iomem *base;
struct hwspinlock *hwlock;
unsigned long slave_vbase;
unsigned long slave_pbase;
struct notifier_block restart_handler;
};
static int sprd_adi_check_paddr(struct sprd_adi *sadi, u32 paddr)
{
if (paddr < sadi->slave_pbase || paddr >
(sadi->slave_pbase + ADI_SLAVE_ADDR_SIZE)) {
dev_err(sadi->dev,
"slave physical address is incorrect, addr = 0x%x\n",
paddr);
return -EINVAL;
}
return 0;
}
static unsigned long sprd_adi_to_vaddr(struct sprd_adi *sadi, u32 paddr)
{
return (paddr - sadi->slave_pbase + sadi->slave_vbase);
}
static int sprd_adi_drain_fifo(struct sprd_adi *sadi)
{
u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
u32 sts;
do {
sts = readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS);
if (sts & BIT_FIFO_EMPTY)
break;
cpu_relax();
} while (--timeout);
if (timeout == 0) {
dev_err(sadi->dev, "drain write fifo timeout\n");
return -EBUSY;
}
return 0;
}
static int sprd_adi_fifo_is_full(struct sprd_adi *sadi)
{
return readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS) & BIT_FIFO_FULL;
}
static int sprd_adi_read(struct sprd_adi *sadi, u32 reg_paddr, u32 *read_val)
{
int read_timeout = ADI_READ_TIMEOUT;
unsigned long flags;
u32 val, rd_addr;
int ret;
ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
ADI_HWSPINLOCK_TIMEOUT,
&flags);
if (ret) {
dev_err(sadi->dev, "get the hw lock failed\n");
return ret;
}
/*
* Set the physical register address need to read into RD_CMD register,
* then ADI controller will start to transfer automatically.
*/
writel_relaxed(reg_paddr, sadi->base + REG_ADI_RD_CMD);
/*
* Wait read operation complete, the BIT_RD_CMD_BUSY will be set
* simultaneously when writing read command to register, and the
* BIT_RD_CMD_BUSY will be cleared after the read operation is
* completed.
*/
do {
val = readl_relaxed(sadi->base + REG_ADI_RD_DATA);
if (!(val & BIT_RD_CMD_BUSY))
break;
cpu_relax();
} while (--read_timeout);
if (read_timeout == 0) {
dev_err(sadi->dev, "ADI read timeout\n");
ret = -EBUSY;
goto out;
}
/*
* The return value includes data and read register address, from bit 0
* to bit 15 are data, and from bit 16 to bit 30 are read register
* address. Then we can check the returned register address to validate
* data.
*/
rd_addr = (val & RD_ADDR_MASK ) >> RD_ADDR_SHIFT;
if (rd_addr != (reg_paddr & REG_ADDR_LOW_MASK)) {
dev_err(sadi->dev, "read error, reg addr = 0x%x, val = 0x%x\n",
reg_paddr, val);
ret = -EIO;
goto out;
}
*read_val = val & RD_VALUE_MASK;
out:
hwspin_unlock_irqrestore(sadi->hwlock, &flags);
return ret;
}
static int sprd_adi_write(struct sprd_adi *sadi, u32 reg_paddr, u32 val)
{
unsigned long reg = sprd_adi_to_vaddr(sadi, reg_paddr);
u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
unsigned long flags;
int ret;
ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
ADI_HWSPINLOCK_TIMEOUT,
&flags);
if (ret) {
dev_err(sadi->dev, "get the hw lock failed\n");
return ret;
}
ret = sprd_adi_drain_fifo(sadi);
if (ret < 0)
goto out;
/*
* we should wait for write fifo is empty before writing data to PMIC
* registers.
*/
do {
if (!sprd_adi_fifo_is_full(sadi)) {
writel_relaxed(val, (void __iomem *)reg);
break;
}
cpu_relax();
} while (--timeout);
if (timeout == 0) {
dev_err(sadi->dev, "write fifo is full\n");
ret = -EBUSY;
}
out:
hwspin_unlock_irqrestore(sadi->hwlock, &flags);
return ret;
}
static int sprd_adi_transfer_one(struct spi_controller *ctlr,
struct spi_device *spi_dev,
struct spi_transfer *t)
{
struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
u32 phy_reg, val;
int ret;
if (t->rx_buf) {
phy_reg = *(u32 *)t->rx_buf + sadi->slave_pbase;
ret = sprd_adi_check_paddr(sadi, phy_reg);
if (ret)
return ret;
ret = sprd_adi_read(sadi, phy_reg, &val);
if (ret)
return ret;
*(u32 *)t->rx_buf = val;
} else if (t->tx_buf) {
u32 *p = (u32 *)t->tx_buf;
/*
* Get the physical register address need to write and convert
* the physical address to virtual address. Since we need
* virtual register address to write.
*/
phy_reg = *p++ + sadi->slave_pbase;
ret = sprd_adi_check_paddr(sadi, phy_reg);
if (ret)
return ret;
val = *p;
ret = sprd_adi_write(sadi, phy_reg, val);
if (ret)
return ret;
} else {
dev_err(sadi->dev, "no buffer for transfer\n");
return -EINVAL;
}
return 0;
}
static int sprd_adi_restart_handler(struct notifier_block *this,
unsigned long mode, void *cmd)
{
struct sprd_adi *sadi = container_of(this, struct sprd_adi,
restart_handler);
u32 val, reboot_mode = 0;
if (!cmd)
reboot_mode = HWRST_STATUS_NORMAL;
else if (!strncmp(cmd, "recovery", 8))
reboot_mode = HWRST_STATUS_RECOVERY;
else if (!strncmp(cmd, "alarm", 5))
reboot_mode = HWRST_STATUS_ALARM;
else if (!strncmp(cmd, "fastsleep", 9))
reboot_mode = HWRST_STATUS_SLEEP;
else if (!strncmp(cmd, "bootloader", 10))
reboot_mode = HWRST_STATUS_FASTBOOT;
else if (!strncmp(cmd, "panic", 5))
reboot_mode = HWRST_STATUS_PANIC;
else if (!strncmp(cmd, "special", 7))
reboot_mode = HWRST_STATUS_SPECIAL;
else if (!strncmp(cmd, "cftreboot", 9))
reboot_mode = HWRST_STATUS_CFTREBOOT;
else if (!strncmp(cmd, "autodloader", 11))
reboot_mode = HWRST_STATUS_AUTODLOADER;
else if (!strncmp(cmd, "iqmode", 6))
reboot_mode = HWRST_STATUS_IQMODE;
else if (!strncmp(cmd, "sprdisk", 7))
reboot_mode = HWRST_STATUS_SPRDISK;
else
reboot_mode = HWRST_STATUS_NORMAL;
/* Record the reboot mode */
sprd_adi_read(sadi, sadi->slave_pbase + PMIC_RST_STATUS, &val);
val |= reboot_mode;
sprd_adi_write(sadi, sadi->slave_pbase + PMIC_RST_STATUS, val);
/* Enable the interface clock of the watchdog */
sprd_adi_read(sadi, sadi->slave_pbase + PMIC_MODULE_EN, &val);
val |= BIT_WDG_EN;
sprd_adi_write(sadi, sadi->slave_pbase + PMIC_MODULE_EN, val);
/* Enable the work clock of the watchdog */
sprd_adi_read(sadi, sadi->slave_pbase + PMIC_CLK_EN, &val);
val |= BIT_WDG_EN;
sprd_adi_write(sadi, sadi->slave_pbase + PMIC_CLK_EN, val);
/* Unlock the watchdog */
sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOCK, WDG_UNLOCK_KEY);
/* Load the watchdog timeout value, 50ms is always enough. */
sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOAD_LOW,
WDG_LOAD_VAL & WDG_LOAD_MASK);
sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOAD_HIGH, 0);
/* Start the watchdog to reset system */
sprd_adi_read(sadi, sadi->slave_pbase + REG_WDG_CTRL, &val);
val |= BIT_WDG_RUN | BIT_WDG_RST;
sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_CTRL, val);
mdelay(1000);
dev_emerg(sadi->dev, "Unable to restart system\n");
return NOTIFY_DONE;
}
static void sprd_adi_hw_init(struct sprd_adi *sadi)
{
struct device_node *np = sadi->dev->of_node;
int i, size, chn_cnt;
const __be32 *list;
u32 tmp;
/* Address bits select default 12 bits */
writel_relaxed(0, sadi->base + REG_ADI_CTRL0);
/* Set all channels as default priority */
writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIL);
writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIH);
/* Set clock auto gate mode */
tmp = readl_relaxed(sadi->base + REG_ADI_GSSI_CFG0);
tmp &= ~BIT_CLK_ALL_ON;
writel_relaxed(tmp, sadi->base + REG_ADI_GSSI_CFG0);
/* Set hardware channels setting */
list = of_get_property(np, "sprd,hw-channels", &size);
if (!list || !size) {
dev_info(sadi->dev, "no hw channels setting in node\n");
return;
}
chn_cnt = size / 8;
for (i = 0; i < chn_cnt; i++) {
u32 value;
u32 chn_id = be32_to_cpu(*list++);
u32 chn_config = be32_to_cpu(*list++);
/* Channel 0 and 1 are software channels */
if (chn_id < 2)
continue;
writel_relaxed(chn_config, sadi->base +
REG_ADI_CHN_ADDR(chn_id));
if (chn_id < 32) {
value = readl_relaxed(sadi->base + REG_ADI_CHN_EN);
value |= BIT(chn_id);
writel_relaxed(value, sadi->base + REG_ADI_CHN_EN);
} else if (chn_id < ADI_HW_CHNS) {
value = readl_relaxed(sadi->base + REG_ADI_CHN_EN1);
value |= BIT(chn_id - 32);
writel_relaxed(value, sadi->base + REG_ADI_CHN_EN1);
}
}
}
static int sprd_adi_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct spi_controller *ctlr;
struct sprd_adi *sadi;
struct resource *res;
u32 num_chipselect;
int ret;
if (!np) {
dev_err(&pdev->dev, "can not find the adi bus node\n");
return -ENODEV;
}
pdev->id = of_alias_get_id(np, "spi");
num_chipselect = of_get_child_count(np);
ctlr = spi_alloc_master(&pdev->dev, sizeof(struct sprd_adi));
if (!ctlr)
return -ENOMEM;
dev_set_drvdata(&pdev->dev, ctlr);
sadi = spi_controller_get_devdata(ctlr);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
sadi->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(sadi->base)) {
ret = PTR_ERR(sadi->base);
goto put_ctlr;
}
sadi->slave_vbase = (unsigned long)sadi->base + ADI_SLAVE_OFFSET;
sadi->slave_pbase = res->start + ADI_SLAVE_OFFSET;
sadi->ctlr = ctlr;
sadi->dev = &pdev->dev;
ret = of_hwspin_lock_get_id(np, 0);
if (ret < 0) {
dev_err(&pdev->dev, "can not get the hardware spinlock\n");
goto put_ctlr;
}
sadi->hwlock = hwspin_lock_request_specific(ret);
if (!sadi->hwlock) {
ret = -ENXIO;
goto put_ctlr;
}
sprd_adi_hw_init(sadi);
ctlr->dev.of_node = pdev->dev.of_node;
ctlr->bus_num = pdev->id;
ctlr->num_chipselect = num_chipselect;
ctlr->flags = SPI_MASTER_HALF_DUPLEX;
ctlr->bits_per_word_mask = 0;
ctlr->transfer_one = sprd_adi_transfer_one;
ret = devm_spi_register_controller(&pdev->dev, ctlr);
if (ret) {
dev_err(&pdev->dev, "failed to register SPI controller\n");
goto free_hwlock;
}
sadi->restart_handler.notifier_call = sprd_adi_restart_handler;
sadi->restart_handler.priority = 128;
ret = register_restart_handler(&sadi->restart_handler);
if (ret) {
dev_err(&pdev->dev, "can not register restart handler\n");
goto free_hwlock;
}
return 0;
free_hwlock:
hwspin_lock_free(sadi->hwlock);
put_ctlr:
spi_controller_put(ctlr);
return ret;
}
static int sprd_adi_remove(struct platform_device *pdev)
{
struct spi_controller *ctlr = dev_get_drvdata(&pdev->dev);
struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
unregister_restart_handler(&sadi->restart_handler);
hwspin_lock_free(sadi->hwlock);
return 0;
}
static const struct of_device_id sprd_adi_of_match[] = {
{
.compatible = "sprd,sc9860-adi",
},
{ },
};
MODULE_DEVICE_TABLE(of, sprd_adi_of_match);
static struct platform_driver sprd_adi_driver = {
.driver = {
.name = "sprd-adi",
.of_match_table = sprd_adi_of_match,
},
.probe = sprd_adi_probe,
.remove = sprd_adi_remove,
};
module_platform_driver(sprd_adi_driver);
MODULE_DESCRIPTION("Spreadtrum ADI Controller Driver");
MODULE_AUTHOR("Baolin Wang <Baolin.Wang@spreadtrum.com>");
MODULE_LICENSE("GPL v2");