linux/drivers/watchdog/s3c2410_wdt.c
Sam Protsenko f7bcb02390 watchdog: s3c2410: Fix getting the optional clock
"watchdog_src" clock is optional and may not be present for some SoCs
supported by this driver. Nevertheless, in case the clock is provided
but some error happens during its getting, that error should be handled
properly. Use devm_clk_get_optional() API for that. Also report possible
errors using dev_err_probe() to handle properly -EPROBE_DEFER error (if
clock provider is not ready by the time WDT probe function is executed).

Fixes: e249d01b5e ("watchdog: s3c2410: Support separate source clock")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Suggested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211212170247.30646-1-semen.protsenko@linaro.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2022-01-05 10:38:37 +01:00

910 lines
24 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2004 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*
* S3C2410 Watchdog Timer Support
*
* Based on, softdog.c by Alan Cox,
* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/cpufreq.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/delay.h>
#define S3C2410_WTCON 0x00
#define S3C2410_WTDAT 0x04
#define S3C2410_WTCNT 0x08
#define S3C2410_WTCLRINT 0x0c
#define S3C2410_WTCNT_MAXCNT 0xffff
#define S3C2410_WTCON_RSTEN (1 << 0)
#define S3C2410_WTCON_INTEN (1 << 2)
#define S3C2410_WTCON_ENABLE (1 << 5)
#define S3C2410_WTCON_DIV16 (0 << 3)
#define S3C2410_WTCON_DIV32 (1 << 3)
#define S3C2410_WTCON_DIV64 (2 << 3)
#define S3C2410_WTCON_DIV128 (3 << 3)
#define S3C2410_WTCON_MAXDIV 0x80
#define S3C2410_WTCON_PRESCALE(x) ((x) << 8)
#define S3C2410_WTCON_PRESCALE_MASK (0xff << 8)
#define S3C2410_WTCON_PRESCALE_MAX 0xff
#define S3C2410_WATCHDOG_ATBOOT (0)
#define S3C2410_WATCHDOG_DEFAULT_TIME (15)
#define EXYNOS5_RST_STAT_REG_OFFSET 0x0404
#define EXYNOS5_WDT_DISABLE_REG_OFFSET 0x0408
#define EXYNOS5_WDT_MASK_RESET_REG_OFFSET 0x040c
#define EXYNOS850_CLUSTER0_NONCPU_OUT 0x1220
#define EXYNOS850_CLUSTER0_NONCPU_INT_EN 0x1244
#define EXYNOS850_CLUSTER1_NONCPU_OUT 0x1620
#define EXYNOS850_CLUSTER1_NONCPU_INT_EN 0x1644
#define EXYNOS850_CLUSTER0_WDTRESET_BIT 24
#define EXYNOS850_CLUSTER1_WDTRESET_BIT 23
/**
* DOC: Quirk flags for different Samsung watchdog IP-cores
*
* This driver supports multiple Samsung SoCs, each of which might have
* different set of registers and features supported. As watchdog block
* sometimes requires modifying PMU registers for proper functioning, register
* differences in both watchdog and PMU IP-cores should be accounted for. Quirk
* flags described below serve the purpose of telling the driver about mentioned
* SoC traits, and can be specified in driver data for each particular supported
* device.
*
* %QUIRK_HAS_WTCLRINT_REG: Watchdog block has WTCLRINT register. It's used to
* clear the interrupt once the interrupt service routine is complete. It's
* write-only, writing any values to this register clears the interrupt, but
* reading is not permitted.
*
* %QUIRK_HAS_PMU_MASK_RESET: PMU block has the register for disabling/enabling
* WDT reset request. On old SoCs it's usually called MASK_WDT_RESET_REQUEST,
* new SoCs have CLUSTERx_NONCPU_INT_EN register, which 'mask_bit' value is
* inverted compared to the former one.
*
* %QUIRK_HAS_PMU_RST_STAT: PMU block has RST_STAT (reset status) register,
* which contains bits indicating the reason for most recent CPU reset. If
* present, driver will use this register to check if previous reboot was due to
* watchdog timer reset.
*
* %QUIRK_HAS_PMU_AUTO_DISABLE: PMU block has AUTOMATIC_WDT_RESET_DISABLE
* register. If 'mask_bit' bit is set, PMU will disable WDT reset when
* corresponding processor is in reset state.
*
* %QUIRK_HAS_PMU_CNT_EN: PMU block has some register (e.g. CLUSTERx_NONCPU_OUT)
* with "watchdog counter enable" bit. That bit should be set to make watchdog
* counter running.
*/
#define QUIRK_HAS_WTCLRINT_REG (1 << 0)
#define QUIRK_HAS_PMU_MASK_RESET (1 << 1)
#define QUIRK_HAS_PMU_RST_STAT (1 << 2)
#define QUIRK_HAS_PMU_AUTO_DISABLE (1 << 3)
#define QUIRK_HAS_PMU_CNT_EN (1 << 4)
/* These quirks require that we have a PMU register map */
#define QUIRKS_HAVE_PMUREG \
(QUIRK_HAS_PMU_MASK_RESET | QUIRK_HAS_PMU_RST_STAT | \
QUIRK_HAS_PMU_AUTO_DISABLE | QUIRK_HAS_PMU_CNT_EN)
static bool nowayout = WATCHDOG_NOWAYOUT;
static int tmr_margin;
static int tmr_atboot = S3C2410_WATCHDOG_ATBOOT;
static int soft_noboot;
module_param(tmr_margin, int, 0);
module_param(tmr_atboot, int, 0);
module_param(nowayout, bool, 0);
module_param(soft_noboot, int, 0);
MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. (default="
__MODULE_STRING(S3C2410_WATCHDOG_DEFAULT_TIME) ")");
MODULE_PARM_DESC(tmr_atboot,
"Watchdog is started at boot time if set to 1, default="
__MODULE_STRING(S3C2410_WATCHDOG_ATBOOT));
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, 0 to reboot (default 0)");
/**
* struct s3c2410_wdt_variant - Per-variant config data
*
* @disable_reg: Offset in pmureg for the register that disables the watchdog
* timer reset functionality.
* @mask_reset_reg: Offset in pmureg for the register that masks the watchdog
* timer reset functionality.
* @mask_reset_inv: If set, mask_reset_reg value will have inverted meaning.
* @mask_bit: Bit number for the watchdog timer in the disable register and the
* mask reset register.
* @rst_stat_reg: Offset in pmureg for the register that has the reset status.
* @rst_stat_bit: Bit number in the rst_stat register indicating a watchdog
* reset.
* @cnt_en_reg: Offset in pmureg for the register that enables WDT counter.
* @cnt_en_bit: Bit number for "watchdog counter enable" in cnt_en register.
* @quirks: A bitfield of quirks.
*/
struct s3c2410_wdt_variant {
int disable_reg;
int mask_reset_reg;
bool mask_reset_inv;
int mask_bit;
int rst_stat_reg;
int rst_stat_bit;
int cnt_en_reg;
int cnt_en_bit;
u32 quirks;
};
struct s3c2410_wdt {
struct device *dev;
struct clk *bus_clk; /* for register interface (PCLK) */
struct clk *src_clk; /* for WDT counter */
void __iomem *reg_base;
unsigned int count;
spinlock_t lock;
unsigned long wtcon_save;
unsigned long wtdat_save;
struct watchdog_device wdt_device;
struct notifier_block freq_transition;
const struct s3c2410_wdt_variant *drv_data;
struct regmap *pmureg;
};
static const struct s3c2410_wdt_variant drv_data_s3c2410 = {
.quirks = 0
};
#ifdef CONFIG_OF
static const struct s3c2410_wdt_variant drv_data_s3c6410 = {
.quirks = QUIRK_HAS_WTCLRINT_REG,
};
static const struct s3c2410_wdt_variant drv_data_exynos5250 = {
.disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
.mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
.mask_bit = 20,
.rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
.rst_stat_bit = 20,
.quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_AUTO_DISABLE,
};
static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
.disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
.mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
.mask_bit = 0,
.rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
.rst_stat_bit = 9,
.quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_AUTO_DISABLE,
};
static const struct s3c2410_wdt_variant drv_data_exynos7 = {
.disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
.mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
.mask_bit = 23,
.rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
.rst_stat_bit = 23, /* A57 WDTRESET */
.quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_AUTO_DISABLE,
};
static const struct s3c2410_wdt_variant drv_data_exynos850_cl0 = {
.mask_reset_reg = EXYNOS850_CLUSTER0_NONCPU_INT_EN,
.mask_bit = 2,
.mask_reset_inv = true,
.rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
.rst_stat_bit = EXYNOS850_CLUSTER0_WDTRESET_BIT,
.cnt_en_reg = EXYNOS850_CLUSTER0_NONCPU_OUT,
.cnt_en_bit = 7,
.quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_CNT_EN,
};
static const struct s3c2410_wdt_variant drv_data_exynos850_cl1 = {
.mask_reset_reg = EXYNOS850_CLUSTER1_NONCPU_INT_EN,
.mask_bit = 2,
.mask_reset_inv = true,
.rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
.rst_stat_bit = EXYNOS850_CLUSTER1_WDTRESET_BIT,
.cnt_en_reg = EXYNOS850_CLUSTER1_NONCPU_OUT,
.cnt_en_bit = 7,
.quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_CNT_EN,
};
static const struct of_device_id s3c2410_wdt_match[] = {
{ .compatible = "samsung,s3c2410-wdt",
.data = &drv_data_s3c2410 },
{ .compatible = "samsung,s3c6410-wdt",
.data = &drv_data_s3c6410 },
{ .compatible = "samsung,exynos5250-wdt",
.data = &drv_data_exynos5250 },
{ .compatible = "samsung,exynos5420-wdt",
.data = &drv_data_exynos5420 },
{ .compatible = "samsung,exynos7-wdt",
.data = &drv_data_exynos7 },
{ .compatible = "samsung,exynos850-wdt",
.data = &drv_data_exynos850_cl0 },
{},
};
MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
#endif
static const struct platform_device_id s3c2410_wdt_ids[] = {
{
.name = "s3c2410-wdt",
.driver_data = (unsigned long)&drv_data_s3c2410,
},
{}
};
MODULE_DEVICE_TABLE(platform, s3c2410_wdt_ids);
/* functions */
static inline unsigned long s3c2410wdt_get_freq(struct s3c2410_wdt *wdt)
{
return clk_get_rate(wdt->src_clk ? wdt->src_clk : wdt->bus_clk);
}
static inline unsigned int s3c2410wdt_max_timeout(struct s3c2410_wdt *wdt)
{
const unsigned long freq = s3c2410wdt_get_freq(wdt);
return S3C2410_WTCNT_MAXCNT / (freq / (S3C2410_WTCON_PRESCALE_MAX + 1)
/ S3C2410_WTCON_MAXDIV);
}
static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb)
{
return container_of(nb, struct s3c2410_wdt, freq_transition);
}
static int s3c2410wdt_disable_wdt_reset(struct s3c2410_wdt *wdt, bool mask)
{
const u32 mask_val = BIT(wdt->drv_data->mask_bit);
const u32 val = mask ? mask_val : 0;
int ret;
ret = regmap_update_bits(wdt->pmureg, wdt->drv_data->disable_reg,
mask_val, val);
if (ret < 0)
dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
return ret;
}
static int s3c2410wdt_mask_wdt_reset(struct s3c2410_wdt *wdt, bool mask)
{
const u32 mask_val = BIT(wdt->drv_data->mask_bit);
const bool val_inv = wdt->drv_data->mask_reset_inv;
const u32 val = (mask ^ val_inv) ? mask_val : 0;
int ret;
ret = regmap_update_bits(wdt->pmureg, wdt->drv_data->mask_reset_reg,
mask_val, val);
if (ret < 0)
dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
return ret;
}
static int s3c2410wdt_enable_counter(struct s3c2410_wdt *wdt, bool en)
{
const u32 mask_val = BIT(wdt->drv_data->cnt_en_bit);
const u32 val = en ? mask_val : 0;
int ret;
ret = regmap_update_bits(wdt->pmureg, wdt->drv_data->cnt_en_reg,
mask_val, val);
if (ret < 0)
dev_err(wdt->dev, "failed to update reg(%d)\n", ret);
return ret;
}
static int s3c2410wdt_enable(struct s3c2410_wdt *wdt, bool en)
{
int ret;
if (wdt->drv_data->quirks & QUIRK_HAS_PMU_AUTO_DISABLE) {
ret = s3c2410wdt_disable_wdt_reset(wdt, !en);
if (ret < 0)
return ret;
}
if (wdt->drv_data->quirks & QUIRK_HAS_PMU_MASK_RESET) {
ret = s3c2410wdt_mask_wdt_reset(wdt, !en);
if (ret < 0)
return ret;
}
if (wdt->drv_data->quirks & QUIRK_HAS_PMU_CNT_EN) {
ret = s3c2410wdt_enable_counter(wdt, en);
if (ret < 0)
return ret;
}
return 0;
}
static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
{
struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
spin_lock(&wdt->lock);
writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
spin_unlock(&wdt->lock);
return 0;
}
static void __s3c2410wdt_stop(struct s3c2410_wdt *wdt)
{
unsigned long wtcon;
wtcon = readl(wdt->reg_base + S3C2410_WTCON);
wtcon &= ~(S3C2410_WTCON_ENABLE | S3C2410_WTCON_RSTEN);
writel(wtcon, wdt->reg_base + S3C2410_WTCON);
}
static int s3c2410wdt_stop(struct watchdog_device *wdd)
{
struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
spin_lock(&wdt->lock);
__s3c2410wdt_stop(wdt);
spin_unlock(&wdt->lock);
return 0;
}
static int s3c2410wdt_start(struct watchdog_device *wdd)
{
unsigned long wtcon;
struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
spin_lock(&wdt->lock);
__s3c2410wdt_stop(wdt);
wtcon = readl(wdt->reg_base + S3C2410_WTCON);
wtcon |= S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128;
if (soft_noboot) {
wtcon |= S3C2410_WTCON_INTEN;
wtcon &= ~S3C2410_WTCON_RSTEN;
} else {
wtcon &= ~S3C2410_WTCON_INTEN;
wtcon |= S3C2410_WTCON_RSTEN;
}
dev_dbg(wdt->dev, "Starting watchdog: count=0x%08x, wtcon=%08lx\n",
wdt->count, wtcon);
writel(wdt->count, wdt->reg_base + S3C2410_WTDAT);
writel(wdt->count, wdt->reg_base + S3C2410_WTCNT);
writel(wtcon, wdt->reg_base + S3C2410_WTCON);
spin_unlock(&wdt->lock);
return 0;
}
static inline int s3c2410wdt_is_running(struct s3c2410_wdt *wdt)
{
return readl(wdt->reg_base + S3C2410_WTCON) & S3C2410_WTCON_ENABLE;
}
static int s3c2410wdt_set_heartbeat(struct watchdog_device *wdd,
unsigned int timeout)
{
struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
unsigned long freq = s3c2410wdt_get_freq(wdt);
unsigned int count;
unsigned int divisor = 1;
unsigned long wtcon;
if (timeout < 1)
return -EINVAL;
freq = DIV_ROUND_UP(freq, 128);
count = timeout * freq;
dev_dbg(wdt->dev, "Heartbeat: count=%d, timeout=%d, freq=%lu\n",
count, timeout, freq);
/* if the count is bigger than the watchdog register,
then work out what we need to do (and if) we can
actually make this value
*/
if (count >= 0x10000) {
divisor = DIV_ROUND_UP(count, 0xffff);
if (divisor > 0x100) {
dev_err(wdt->dev, "timeout %d too big\n", timeout);
return -EINVAL;
}
}
dev_dbg(wdt->dev, "Heartbeat: timeout=%d, divisor=%d, count=%d (%08x)\n",
timeout, divisor, count, DIV_ROUND_UP(count, divisor));
count = DIV_ROUND_UP(count, divisor);
wdt->count = count;
/* update the pre-scaler */
wtcon = readl(wdt->reg_base + S3C2410_WTCON);
wtcon &= ~S3C2410_WTCON_PRESCALE_MASK;
wtcon |= S3C2410_WTCON_PRESCALE(divisor-1);
writel(count, wdt->reg_base + S3C2410_WTDAT);
writel(wtcon, wdt->reg_base + S3C2410_WTCON);
wdd->timeout = (count * divisor) / freq;
return 0;
}
static int s3c2410wdt_restart(struct watchdog_device *wdd, unsigned long action,
void *data)
{
struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
void __iomem *wdt_base = wdt->reg_base;
/* disable watchdog, to be safe */
writel(0, wdt_base + S3C2410_WTCON);
/* put initial values into count and data */
writel(0x80, wdt_base + S3C2410_WTCNT);
writel(0x80, wdt_base + S3C2410_WTDAT);
/* set the watchdog to go and reset... */
writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV16 |
S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x20),
wdt_base + S3C2410_WTCON);
/* wait for reset to assert... */
mdelay(500);
return 0;
}
#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
static const struct watchdog_info s3c2410_wdt_ident = {
.options = OPTIONS,
.firmware_version = 0,
.identity = "S3C2410 Watchdog",
};
static const struct watchdog_ops s3c2410wdt_ops = {
.owner = THIS_MODULE,
.start = s3c2410wdt_start,
.stop = s3c2410wdt_stop,
.ping = s3c2410wdt_keepalive,
.set_timeout = s3c2410wdt_set_heartbeat,
.restart = s3c2410wdt_restart,
};
static const struct watchdog_device s3c2410_wdd = {
.info = &s3c2410_wdt_ident,
.ops = &s3c2410wdt_ops,
.timeout = S3C2410_WATCHDOG_DEFAULT_TIME,
};
/* interrupt handler code */
static irqreturn_t s3c2410wdt_irq(int irqno, void *param)
{
struct s3c2410_wdt *wdt = platform_get_drvdata(param);
dev_info(wdt->dev, "watchdog timer expired (irq)\n");
s3c2410wdt_keepalive(&wdt->wdt_device);
if (wdt->drv_data->quirks & QUIRK_HAS_WTCLRINT_REG)
writel(0x1, wdt->reg_base + S3C2410_WTCLRINT);
return IRQ_HANDLED;
}
#ifdef CONFIG_ARM_S3C24XX_CPUFREQ
static int s3c2410wdt_cpufreq_transition(struct notifier_block *nb,
unsigned long val, void *data)
{
int ret;
struct s3c2410_wdt *wdt = freq_to_wdt(nb);
if (!s3c2410wdt_is_running(wdt))
goto done;
if (val == CPUFREQ_PRECHANGE) {
/* To ensure that over the change we don't cause the
* watchdog to trigger, we perform an keep-alive if
* the watchdog is running.
*/
s3c2410wdt_keepalive(&wdt->wdt_device);
} else if (val == CPUFREQ_POSTCHANGE) {
s3c2410wdt_stop(&wdt->wdt_device);
ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
wdt->wdt_device.timeout);
if (ret >= 0)
s3c2410wdt_start(&wdt->wdt_device);
else
goto err;
}
done:
return 0;
err:
dev_err(wdt->dev, "cannot set new value for timeout %d\n",
wdt->wdt_device.timeout);
return ret;
}
static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt)
{
wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition;
return cpufreq_register_notifier(&wdt->freq_transition,
CPUFREQ_TRANSITION_NOTIFIER);
}
static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
{
wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition;
cpufreq_unregister_notifier(&wdt->freq_transition,
CPUFREQ_TRANSITION_NOTIFIER);
}
#else
static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt)
{
return 0;
}
static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
{
}
#endif
static inline unsigned int s3c2410wdt_get_bootstatus(struct s3c2410_wdt *wdt)
{
unsigned int rst_stat;
int ret;
if (!(wdt->drv_data->quirks & QUIRK_HAS_PMU_RST_STAT))
return 0;
ret = regmap_read(wdt->pmureg, wdt->drv_data->rst_stat_reg, &rst_stat);
if (ret)
dev_warn(wdt->dev, "Couldn't get RST_STAT register\n");
else if (rst_stat & BIT(wdt->drv_data->rst_stat_bit))
return WDIOF_CARDRESET;
return 0;
}
static inline const struct s3c2410_wdt_variant *
s3c2410_get_wdt_drv_data(struct platform_device *pdev)
{
const struct s3c2410_wdt_variant *variant;
struct device *dev = &pdev->dev;
variant = of_device_get_match_data(dev);
if (!variant) {
/* Device matched by platform_device_id */
variant = (struct s3c2410_wdt_variant *)
platform_get_device_id(pdev)->driver_data;
}
#ifdef CONFIG_OF
/* Choose Exynos850 driver data w.r.t. cluster index */
if (variant == &drv_data_exynos850_cl0) {
u32 index;
int err;
err = of_property_read_u32(dev->of_node,
"samsung,cluster-index", &index);
if (err) {
dev_err(dev, "failed to get cluster index\n");
return NULL;
}
switch (index) {
case 0:
return &drv_data_exynos850_cl0;
case 1:
return &drv_data_exynos850_cl1;
default:
dev_err(dev, "wrong cluster index: %u\n", index);
return NULL;
}
}
#endif
return variant;
}
static int s3c2410wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct s3c2410_wdt *wdt;
unsigned int wtcon;
int wdt_irq;
int ret;
wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
wdt->dev = dev;
spin_lock_init(&wdt->lock);
wdt->wdt_device = s3c2410_wdd;
wdt->drv_data = s3c2410_get_wdt_drv_data(pdev);
if (!wdt->drv_data)
return -EINVAL;
if (wdt->drv_data->quirks & QUIRKS_HAVE_PMUREG) {
wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
"samsung,syscon-phandle");
if (IS_ERR(wdt->pmureg)) {
dev_err(dev, "syscon regmap lookup failed.\n");
return PTR_ERR(wdt->pmureg);
}
}
wdt_irq = platform_get_irq(pdev, 0);
if (wdt_irq < 0)
return wdt_irq;
/* get the memory region for the watchdog timer */
wdt->reg_base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(wdt->reg_base))
return PTR_ERR(wdt->reg_base);
wdt->bus_clk = devm_clk_get(dev, "watchdog");
if (IS_ERR(wdt->bus_clk)) {
dev_err(dev, "failed to find bus clock\n");
return PTR_ERR(wdt->bus_clk);
}
ret = clk_prepare_enable(wdt->bus_clk);
if (ret < 0) {
dev_err(dev, "failed to enable bus clock\n");
return ret;
}
/*
* "watchdog_src" clock is optional; if it's not present -- just skip it
* and use "watchdog" clock as both bus and source clock.
*/
wdt->src_clk = devm_clk_get_optional(dev, "watchdog_src");
if (IS_ERR(wdt->src_clk)) {
dev_err_probe(dev, PTR_ERR(wdt->src_clk),
"failed to get source clock\n");
ret = PTR_ERR(wdt->src_clk);
goto err_bus_clk;
}
ret = clk_prepare_enable(wdt->src_clk);
if (ret) {
dev_err(dev, "failed to enable source clock\n");
goto err_bus_clk;
}
wdt->wdt_device.min_timeout = 1;
wdt->wdt_device.max_timeout = s3c2410wdt_max_timeout(wdt);
ret = s3c2410wdt_cpufreq_register(wdt);
if (ret < 0) {
dev_err(dev, "failed to register cpufreq\n");
goto err_src_clk;
}
watchdog_set_drvdata(&wdt->wdt_device, wdt);
/* see if we can actually set the requested timer margin, and if
* not, try the default value */
watchdog_init_timeout(&wdt->wdt_device, tmr_margin, dev);
ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
wdt->wdt_device.timeout);
if (ret) {
ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
S3C2410_WATCHDOG_DEFAULT_TIME);
if (ret == 0) {
dev_warn(dev, "tmr_margin value out of range, default %d used\n",
S3C2410_WATCHDOG_DEFAULT_TIME);
} else {
dev_err(dev, "failed to use default timeout\n");
goto err_cpufreq;
}
}
ret = devm_request_irq(dev, wdt_irq, s3c2410wdt_irq, 0,
pdev->name, pdev);
if (ret != 0) {
dev_err(dev, "failed to install irq (%d)\n", ret);
goto err_cpufreq;
}
watchdog_set_nowayout(&wdt->wdt_device, nowayout);
watchdog_set_restart_priority(&wdt->wdt_device, 128);
wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt);
wdt->wdt_device.parent = dev;
/*
* If "tmr_atboot" param is non-zero, start the watchdog right now. Also
* set WDOG_HW_RUNNING bit, so that watchdog core can kick the watchdog.
*
* If we're not enabling the watchdog, then ensure it is disabled if it
* has been left running from the bootloader or other source.
*/
if (tmr_atboot) {
dev_info(dev, "starting watchdog timer\n");
s3c2410wdt_start(&wdt->wdt_device);
set_bit(WDOG_HW_RUNNING, &wdt->wdt_device.status);
} else {
s3c2410wdt_stop(&wdt->wdt_device);
}
ret = watchdog_register_device(&wdt->wdt_device);
if (ret)
goto err_cpufreq;
ret = s3c2410wdt_enable(wdt, true);
if (ret < 0)
goto err_unregister;
platform_set_drvdata(pdev, wdt);
/* print out a statement of readiness */
wtcon = readl(wdt->reg_base + S3C2410_WTCON);
dev_info(dev, "watchdog %sactive, reset %sabled, irq %sabled\n",
(wtcon & S3C2410_WTCON_ENABLE) ? "" : "in",
(wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis",
(wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis");
return 0;
err_unregister:
watchdog_unregister_device(&wdt->wdt_device);
err_cpufreq:
s3c2410wdt_cpufreq_deregister(wdt);
err_src_clk:
clk_disable_unprepare(wdt->src_clk);
err_bus_clk:
clk_disable_unprepare(wdt->bus_clk);
return ret;
}
static int s3c2410wdt_remove(struct platform_device *dev)
{
int ret;
struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
ret = s3c2410wdt_enable(wdt, false);
if (ret < 0)
return ret;
watchdog_unregister_device(&wdt->wdt_device);
s3c2410wdt_cpufreq_deregister(wdt);
clk_disable_unprepare(wdt->src_clk);
clk_disable_unprepare(wdt->bus_clk);
return 0;
}
static void s3c2410wdt_shutdown(struct platform_device *dev)
{
struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
s3c2410wdt_enable(wdt, false);
s3c2410wdt_stop(&wdt->wdt_device);
}
#ifdef CONFIG_PM_SLEEP
static int s3c2410wdt_suspend(struct device *dev)
{
int ret;
struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
/* Save watchdog state, and turn it off. */
wdt->wtcon_save = readl(wdt->reg_base + S3C2410_WTCON);
wdt->wtdat_save = readl(wdt->reg_base + S3C2410_WTDAT);
ret = s3c2410wdt_enable(wdt, false);
if (ret < 0)
return ret;
/* Note that WTCNT doesn't need to be saved. */
s3c2410wdt_stop(&wdt->wdt_device);
return 0;
}
static int s3c2410wdt_resume(struct device *dev)
{
int ret;
struct s3c2410_wdt *wdt = dev_get_drvdata(dev);
/* Restore watchdog state. */
writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTDAT);
writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTCNT);/* Reset count */
writel(wdt->wtcon_save, wdt->reg_base + S3C2410_WTCON);
ret = s3c2410wdt_enable(wdt, true);
if (ret < 0)
return ret;
dev_info(dev, "watchdog %sabled\n",
(wdt->wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis");
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(s3c2410wdt_pm_ops, s3c2410wdt_suspend,
s3c2410wdt_resume);
static struct platform_driver s3c2410wdt_driver = {
.probe = s3c2410wdt_probe,
.remove = s3c2410wdt_remove,
.shutdown = s3c2410wdt_shutdown,
.id_table = s3c2410_wdt_ids,
.driver = {
.name = "s3c2410-wdt",
.pm = &s3c2410wdt_pm_ops,
.of_match_table = of_match_ptr(s3c2410_wdt_match),
},
};
module_platform_driver(s3c2410wdt_driver);
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>, Dimitry Andric <dimitry.andric@tomtom.com>");
MODULE_DESCRIPTION("S3C2410 Watchdog Device Driver");
MODULE_LICENSE("GPL");