swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 7d2a07b769330c34b4deabeed939325c77a7ec2f authored by Linus Torvalds on 29 August 2021, 22:04:50 UTC
Linux 5.14
Linux 5.14
Tip revision: 7d2a07b
dw_wdt.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 2010-2011 Picochip Ltd., Jamie Iles
* https://www.picochip.com
*
* This file implements a driver for the Synopsys DesignWare watchdog device
* in the many subsystems. The watchdog has 16 different timeout periods
* and these are a function of the input clock frequency.
*
* The DesignWare watchdog cannot be stopped once it has been started so we
* do not implement a stop function. The watchdog core will continue to send
* heartbeat requests after the watchdog device has been closed.
*/
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/limits.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/reset.h>
#include <linux/watchdog.h>
#define WDOG_CONTROL_REG_OFFSET 0x00
#define WDOG_CONTROL_REG_WDT_EN_MASK 0x01
#define WDOG_CONTROL_REG_RESP_MODE_MASK 0x02
#define WDOG_TIMEOUT_RANGE_REG_OFFSET 0x04
#define WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT 4
#define WDOG_CURRENT_COUNT_REG_OFFSET 0x08
#define WDOG_COUNTER_RESTART_REG_OFFSET 0x0c
#define WDOG_COUNTER_RESTART_KICK_VALUE 0x76
#define WDOG_INTERRUPT_STATUS_REG_OFFSET 0x10
#define WDOG_INTERRUPT_CLEAR_REG_OFFSET 0x14
#define WDOG_COMP_PARAMS_5_REG_OFFSET 0xe4
#define WDOG_COMP_PARAMS_4_REG_OFFSET 0xe8
#define WDOG_COMP_PARAMS_3_REG_OFFSET 0xec
#define WDOG_COMP_PARAMS_2_REG_OFFSET 0xf0
#define WDOG_COMP_PARAMS_1_REG_OFFSET 0xf4
#define WDOG_COMP_PARAMS_1_USE_FIX_TOP BIT(6)
#define WDOG_COMP_VERSION_REG_OFFSET 0xf8
#define WDOG_COMP_TYPE_REG_OFFSET 0xfc
/* There are sixteen TOPs (timeout periods) that can be set in the watchdog. */
#define DW_WDT_NUM_TOPS 16
#define DW_WDT_FIX_TOP(_idx) (1U << (16 + _idx))
#define DW_WDT_DEFAULT_SECONDS 30
static const u32 dw_wdt_fix_tops[DW_WDT_NUM_TOPS] = {
DW_WDT_FIX_TOP(0), DW_WDT_FIX_TOP(1), DW_WDT_FIX_TOP(2),
DW_WDT_FIX_TOP(3), DW_WDT_FIX_TOP(4), DW_WDT_FIX_TOP(5),
DW_WDT_FIX_TOP(6), DW_WDT_FIX_TOP(7), DW_WDT_FIX_TOP(8),
DW_WDT_FIX_TOP(9), DW_WDT_FIX_TOP(10), DW_WDT_FIX_TOP(11),
DW_WDT_FIX_TOP(12), DW_WDT_FIX_TOP(13), DW_WDT_FIX_TOP(14),
DW_WDT_FIX_TOP(15)
};
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
enum dw_wdt_rmod {
DW_WDT_RMOD_RESET = 1,
DW_WDT_RMOD_IRQ = 2
};
struct dw_wdt_timeout {
u32 top_val;
unsigned int sec;
unsigned int msec;
};
struct dw_wdt {
void __iomem *regs;
struct clk *clk;
struct clk *pclk;
unsigned long rate;
enum dw_wdt_rmod rmod;
struct dw_wdt_timeout timeouts[DW_WDT_NUM_TOPS];
struct watchdog_device wdd;
struct reset_control *rst;
/* Save/restore */
u32 control;
u32 timeout;
#ifdef CONFIG_DEBUG_FS
struct dentry *dbgfs_dir;
#endif
};
#define to_dw_wdt(wdd) container_of(wdd, struct dw_wdt, wdd)
static inline int dw_wdt_is_enabled(struct dw_wdt *dw_wdt)
{
return readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET) &
WDOG_CONTROL_REG_WDT_EN_MASK;
}
static void dw_wdt_update_mode(struct dw_wdt *dw_wdt, enum dw_wdt_rmod rmod)
{
u32 val;
val = readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
if (rmod == DW_WDT_RMOD_IRQ)
val |= WDOG_CONTROL_REG_RESP_MODE_MASK;
else
val &= ~WDOG_CONTROL_REG_RESP_MODE_MASK;
writel(val, dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
dw_wdt->rmod = rmod;
}
static unsigned int dw_wdt_find_best_top(struct dw_wdt *dw_wdt,
unsigned int timeout, u32 *top_val)
{
int idx;
/*
* Find a TOP with timeout greater or equal to the requested number.
* Note we'll select a TOP with maximum timeout if the requested
* timeout couldn't be reached.
*/
for (idx = 0; idx < DW_WDT_NUM_TOPS; ++idx) {
if (dw_wdt->timeouts[idx].sec >= timeout)
break;
}
if (idx == DW_WDT_NUM_TOPS)
--idx;
*top_val = dw_wdt->timeouts[idx].top_val;
return dw_wdt->timeouts[idx].sec;
}
static unsigned int dw_wdt_get_min_timeout(struct dw_wdt *dw_wdt)
{
int idx;
/*
* We'll find a timeout greater or equal to one second anyway because
* the driver probe would have failed if there was none.
*/
for (idx = 0; idx < DW_WDT_NUM_TOPS; ++idx) {
if (dw_wdt->timeouts[idx].sec)
break;
}
return dw_wdt->timeouts[idx].sec;
}
static unsigned int dw_wdt_get_max_timeout_ms(struct dw_wdt *dw_wdt)
{
struct dw_wdt_timeout *timeout = &dw_wdt->timeouts[DW_WDT_NUM_TOPS - 1];
u64 msec;
msec = (u64)timeout->sec * MSEC_PER_SEC + timeout->msec;
return msec < UINT_MAX ? msec : UINT_MAX;
}
static unsigned int dw_wdt_get_timeout(struct dw_wdt *dw_wdt)
{
int top_val = readl(dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET) & 0xF;
int idx;
for (idx = 0; idx < DW_WDT_NUM_TOPS; ++idx) {
if (dw_wdt->timeouts[idx].top_val == top_val)
break;
}
/*
* In IRQ mode due to the two stages counter, the actual timeout is
* twice greater than the TOP setting.
*/
return dw_wdt->timeouts[idx].sec * dw_wdt->rmod;
}
static int dw_wdt_ping(struct watchdog_device *wdd)
{
struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
writel(WDOG_COUNTER_RESTART_KICK_VALUE, dw_wdt->regs +
WDOG_COUNTER_RESTART_REG_OFFSET);
return 0;
}
static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s)
{
struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
unsigned int timeout;
u32 top_val;
/*
* Note IRQ mode being enabled means having a non-zero pre-timeout
* setup. In this case we try to find a TOP as close to the half of the
* requested timeout as possible since DW Watchdog IRQ mode is designed
* in two stages way - first timeout rises the pre-timeout interrupt,
* second timeout performs the system reset. So basically the effective
* watchdog-caused reset happens after two watchdog TOPs elapsed.
*/
timeout = dw_wdt_find_best_top(dw_wdt, DIV_ROUND_UP(top_s, dw_wdt->rmod),
&top_val);
if (dw_wdt->rmod == DW_WDT_RMOD_IRQ)
wdd->pretimeout = timeout;
else
wdd->pretimeout = 0;
/*
* Set the new value in the watchdog. Some versions of dw_wdt
* have have TOPINIT in the TIMEOUT_RANGE register (as per
* CP_WDT_DUAL_TOP in WDT_COMP_PARAMS_1). On those we
* effectively get a pat of the watchdog right here.
*/
writel(top_val | top_val << WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT,
dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
/* Kick new TOP value into the watchdog counter if activated. */
if (watchdog_active(wdd))
dw_wdt_ping(wdd);
/*
* In case users set bigger timeout value than HW can support,
* kernel(watchdog_dev.c) helps to feed watchdog before
* wdd->max_hw_heartbeat_ms
*/
if (top_s * 1000 <= wdd->max_hw_heartbeat_ms)
wdd->timeout = timeout * dw_wdt->rmod;
else
wdd->timeout = top_s;
return 0;
}
static int dw_wdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req)
{
struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
/*
* We ignore actual value of the timeout passed from user-space
* using it as a flag whether the pretimeout functionality is intended
* to be activated.
*/
dw_wdt_update_mode(dw_wdt, req ? DW_WDT_RMOD_IRQ : DW_WDT_RMOD_RESET);
dw_wdt_set_timeout(wdd, wdd->timeout);
return 0;
}
static void dw_wdt_arm_system_reset(struct dw_wdt *dw_wdt)
{
u32 val = readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
/* Disable/enable interrupt mode depending on the RMOD flag. */
if (dw_wdt->rmod == DW_WDT_RMOD_IRQ)
val |= WDOG_CONTROL_REG_RESP_MODE_MASK;
else
val &= ~WDOG_CONTROL_REG_RESP_MODE_MASK;
/* Enable watchdog. */
val |= WDOG_CONTROL_REG_WDT_EN_MASK;
writel(val, dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
}
static int dw_wdt_start(struct watchdog_device *wdd)
{
struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
dw_wdt_set_timeout(wdd, wdd->timeout);
dw_wdt_ping(&dw_wdt->wdd);
dw_wdt_arm_system_reset(dw_wdt);
return 0;
}
static int dw_wdt_stop(struct watchdog_device *wdd)
{
struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
if (!dw_wdt->rst) {
set_bit(WDOG_HW_RUNNING, &wdd->status);
return 0;
}
reset_control_assert(dw_wdt->rst);
reset_control_deassert(dw_wdt->rst);
return 0;
}
static int dw_wdt_restart(struct watchdog_device *wdd,
unsigned long action, void *data)
{
struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
writel(0, dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
dw_wdt_update_mode(dw_wdt, DW_WDT_RMOD_RESET);
if (dw_wdt_is_enabled(dw_wdt))
writel(WDOG_COUNTER_RESTART_KICK_VALUE,
dw_wdt->regs + WDOG_COUNTER_RESTART_REG_OFFSET);
else
dw_wdt_arm_system_reset(dw_wdt);
/* wait for reset to assert... */
mdelay(500);
return 0;
}
static unsigned int dw_wdt_get_timeleft(struct watchdog_device *wdd)
{
struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
unsigned int sec;
u32 val;
val = readl(dw_wdt->regs + WDOG_CURRENT_COUNT_REG_OFFSET);
sec = val / dw_wdt->rate;
if (dw_wdt->rmod == DW_WDT_RMOD_IRQ) {
val = readl(dw_wdt->regs + WDOG_INTERRUPT_STATUS_REG_OFFSET);
if (!val)
sec += wdd->pretimeout;
}
return sec;
}
static const struct watchdog_info dw_wdt_ident = {
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE,
.identity = "Synopsys DesignWare Watchdog",
};
static const struct watchdog_info dw_wdt_pt_ident = {
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
WDIOF_PRETIMEOUT | WDIOF_MAGICCLOSE,
.identity = "Synopsys DesignWare Watchdog",
};
static const struct watchdog_ops dw_wdt_ops = {
.owner = THIS_MODULE,
.start = dw_wdt_start,
.stop = dw_wdt_stop,
.ping = dw_wdt_ping,
.set_timeout = dw_wdt_set_timeout,
.set_pretimeout = dw_wdt_set_pretimeout,
.get_timeleft = dw_wdt_get_timeleft,
.restart = dw_wdt_restart,
};
static irqreturn_t dw_wdt_irq(int irq, void *devid)
{
struct dw_wdt *dw_wdt = devid;
u32 val;
/*
* We don't clear the IRQ status. It's supposed to be done by the
* following ping operations.
*/
val = readl(dw_wdt->regs + WDOG_INTERRUPT_STATUS_REG_OFFSET);
if (!val)
return IRQ_NONE;
watchdog_notify_pretimeout(&dw_wdt->wdd);
return IRQ_HANDLED;
}
#ifdef CONFIG_PM_SLEEP
static int dw_wdt_suspend(struct device *dev)
{
struct dw_wdt *dw_wdt = dev_get_drvdata(dev);
dw_wdt->control = readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
dw_wdt->timeout = readl(dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
clk_disable_unprepare(dw_wdt->pclk);
clk_disable_unprepare(dw_wdt->clk);
return 0;
}
static int dw_wdt_resume(struct device *dev)
{
struct dw_wdt *dw_wdt = dev_get_drvdata(dev);
int err = clk_prepare_enable(dw_wdt->clk);
if (err)
return err;
err = clk_prepare_enable(dw_wdt->pclk);
if (err) {
clk_disable_unprepare(dw_wdt->clk);
return err;
}
writel(dw_wdt->timeout, dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
writel(dw_wdt->control, dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
dw_wdt_ping(&dw_wdt->wdd);
return 0;
}
#endif /* CONFIG_PM_SLEEP */
static SIMPLE_DEV_PM_OPS(dw_wdt_pm_ops, dw_wdt_suspend, dw_wdt_resume);
/*
* In case if DW WDT IP core is synthesized with fixed TOP feature disabled the
* TOPs array can be arbitrary ordered with nearly any sixteen uint numbers
* depending on the system engineer imagination. The next method handles the
* passed TOPs array to pre-calculate the effective timeouts and to sort the
* TOP items out in the ascending order with respect to the timeouts.
*/
static void dw_wdt_handle_tops(struct dw_wdt *dw_wdt, const u32 *tops)
{
struct dw_wdt_timeout tout, *dst;
int val, tidx;
u64 msec;
/*
* We walk over the passed TOPs array and calculate corresponding
* timeouts in seconds and milliseconds. The milliseconds granularity
* is needed to distinguish the TOPs with very close timeouts and to
* set the watchdog max heartbeat setting further.
*/
for (val = 0; val < DW_WDT_NUM_TOPS; ++val) {
tout.top_val = val;
tout.sec = tops[val] / dw_wdt->rate;
msec = (u64)tops[val] * MSEC_PER_SEC;
do_div(msec, dw_wdt->rate);
tout.msec = msec - ((u64)tout.sec * MSEC_PER_SEC);
/*
* Find a suitable place for the current TOP in the timeouts
* array so that the list is remained in the ascending order.
*/
for (tidx = 0; tidx < val; ++tidx) {
dst = &dw_wdt->timeouts[tidx];
if (tout.sec > dst->sec || (tout.sec == dst->sec &&
tout.msec >= dst->msec))
continue;
else
swap(*dst, tout);
}
dw_wdt->timeouts[val] = tout;
}
}
static int dw_wdt_init_timeouts(struct dw_wdt *dw_wdt, struct device *dev)
{
u32 data, of_tops[DW_WDT_NUM_TOPS];
const u32 *tops;
int ret;
/*
* Retrieve custom or fixed counter values depending on the
* WDT_USE_FIX_TOP flag found in the component specific parameters
* #1 register.
*/
data = readl(dw_wdt->regs + WDOG_COMP_PARAMS_1_REG_OFFSET);
if (data & WDOG_COMP_PARAMS_1_USE_FIX_TOP) {
tops = dw_wdt_fix_tops;
} else {
ret = of_property_read_variable_u32_array(dev_of_node(dev),
"snps,watchdog-tops", of_tops, DW_WDT_NUM_TOPS,
DW_WDT_NUM_TOPS);
if (ret < 0) {
dev_warn(dev, "No valid TOPs array specified\n");
tops = dw_wdt_fix_tops;
} else {
tops = of_tops;
}
}
/* Convert the specified TOPs into an array of watchdog timeouts. */
dw_wdt_handle_tops(dw_wdt, tops);
if (!dw_wdt->timeouts[DW_WDT_NUM_TOPS - 1].sec) {
dev_err(dev, "No any valid TOP detected\n");
return -EINVAL;
}
return 0;
}
#ifdef CONFIG_DEBUG_FS
#define DW_WDT_DBGFS_REG(_name, _off) \
{ \
.name = _name, \
.offset = _off \
}
static const struct debugfs_reg32 dw_wdt_dbgfs_regs[] = {
DW_WDT_DBGFS_REG("cr", WDOG_CONTROL_REG_OFFSET),
DW_WDT_DBGFS_REG("torr", WDOG_TIMEOUT_RANGE_REG_OFFSET),
DW_WDT_DBGFS_REG("ccvr", WDOG_CURRENT_COUNT_REG_OFFSET),
DW_WDT_DBGFS_REG("crr", WDOG_COUNTER_RESTART_REG_OFFSET),
DW_WDT_DBGFS_REG("stat", WDOG_INTERRUPT_STATUS_REG_OFFSET),
DW_WDT_DBGFS_REG("param5", WDOG_COMP_PARAMS_5_REG_OFFSET),
DW_WDT_DBGFS_REG("param4", WDOG_COMP_PARAMS_4_REG_OFFSET),
DW_WDT_DBGFS_REG("param3", WDOG_COMP_PARAMS_3_REG_OFFSET),
DW_WDT_DBGFS_REG("param2", WDOG_COMP_PARAMS_2_REG_OFFSET),
DW_WDT_DBGFS_REG("param1", WDOG_COMP_PARAMS_1_REG_OFFSET),
DW_WDT_DBGFS_REG("version", WDOG_COMP_VERSION_REG_OFFSET),
DW_WDT_DBGFS_REG("type", WDOG_COMP_TYPE_REG_OFFSET)
};
static void dw_wdt_dbgfs_init(struct dw_wdt *dw_wdt)
{
struct device *dev = dw_wdt->wdd.parent;
struct debugfs_regset32 *regset;
regset = devm_kzalloc(dev, sizeof(*regset), GFP_KERNEL);
if (!regset)
return;
regset->regs = dw_wdt_dbgfs_regs;
regset->nregs = ARRAY_SIZE(dw_wdt_dbgfs_regs);
regset->base = dw_wdt->regs;
dw_wdt->dbgfs_dir = debugfs_create_dir(dev_name(dev), NULL);
debugfs_create_regset32("registers", 0444, dw_wdt->dbgfs_dir, regset);
}
static void dw_wdt_dbgfs_clear(struct dw_wdt *dw_wdt)
{
debugfs_remove_recursive(dw_wdt->dbgfs_dir);
}
#else /* !CONFIG_DEBUG_FS */
static void dw_wdt_dbgfs_init(struct dw_wdt *dw_wdt) {}
static void dw_wdt_dbgfs_clear(struct dw_wdt *dw_wdt) {}
#endif /* !CONFIG_DEBUG_FS */
static int dw_wdt_drv_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct watchdog_device *wdd;
struct dw_wdt *dw_wdt;
int ret;
dw_wdt = devm_kzalloc(dev, sizeof(*dw_wdt), GFP_KERNEL);
if (!dw_wdt)
return -ENOMEM;
dw_wdt->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(dw_wdt->regs))
return PTR_ERR(dw_wdt->regs);
/*
* Try to request the watchdog dedicated timer clock source. It must
* be supplied if asynchronous mode is enabled. Otherwise fallback
* to the common timer/bus clocks configuration, in which the very
* first found clock supply both timer and APB signals.
*/
dw_wdt->clk = devm_clk_get(dev, "tclk");
if (IS_ERR(dw_wdt->clk)) {
dw_wdt->clk = devm_clk_get(dev, NULL);
if (IS_ERR(dw_wdt->clk))
return PTR_ERR(dw_wdt->clk);
}
ret = clk_prepare_enable(dw_wdt->clk);
if (ret)
return ret;
dw_wdt->rate = clk_get_rate(dw_wdt->clk);
if (dw_wdt->rate == 0) {
ret = -EINVAL;
goto out_disable_clk;
}
/*
* Request APB clock if device is configured with async clocks mode.
* In this case both tclk and pclk clocks are supposed to be specified.
* Alas we can't know for sure whether async mode was really activated,
* so the pclk phandle reference is left optional. If it couldn't be
* found we consider the device configured in synchronous clocks mode.
*/
dw_wdt->pclk = devm_clk_get_optional(dev, "pclk");
if (IS_ERR(dw_wdt->pclk)) {
ret = PTR_ERR(dw_wdt->pclk);
goto out_disable_clk;
}
ret = clk_prepare_enable(dw_wdt->pclk);
if (ret)
goto out_disable_clk;
dw_wdt->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
if (IS_ERR(dw_wdt->rst)) {
ret = PTR_ERR(dw_wdt->rst);
goto out_disable_pclk;
}
/* Enable normal reset without pre-timeout by default. */
dw_wdt_update_mode(dw_wdt, DW_WDT_RMOD_RESET);
/*
* Pre-timeout IRQ is optional, since some hardware may lack support
* of it. Note we must request rising-edge IRQ, since the lane is left
* pending either until the next watchdog kick event or up to the
* system reset.
*/
ret = platform_get_irq_optional(pdev, 0);
if (ret > 0) {
ret = devm_request_irq(dev, ret, dw_wdt_irq,
IRQF_SHARED | IRQF_TRIGGER_RISING,
pdev->name, dw_wdt);
if (ret)
goto out_disable_pclk;
dw_wdt->wdd.info = &dw_wdt_pt_ident;
} else {
if (ret == -EPROBE_DEFER)
goto out_disable_pclk;
dw_wdt->wdd.info = &dw_wdt_ident;
}
reset_control_deassert(dw_wdt->rst);
ret = dw_wdt_init_timeouts(dw_wdt, dev);
if (ret)
goto out_disable_clk;
wdd = &dw_wdt->wdd;
wdd->ops = &dw_wdt_ops;
wdd->min_timeout = dw_wdt_get_min_timeout(dw_wdt);
wdd->max_hw_heartbeat_ms = dw_wdt_get_max_timeout_ms(dw_wdt);
wdd->parent = dev;
watchdog_set_drvdata(wdd, dw_wdt);
watchdog_set_nowayout(wdd, nowayout);
watchdog_init_timeout(wdd, 0, dev);
/*
* If the watchdog is already running, use its already configured
* timeout. Otherwise use the default or the value provided through
* devicetree.
*/
if (dw_wdt_is_enabled(dw_wdt)) {
wdd->timeout = dw_wdt_get_timeout(dw_wdt);
set_bit(WDOG_HW_RUNNING, &wdd->status);
} else {
wdd->timeout = DW_WDT_DEFAULT_SECONDS;
watchdog_init_timeout(wdd, 0, dev);
}
platform_set_drvdata(pdev, dw_wdt);
watchdog_set_restart_priority(wdd, 128);
ret = watchdog_register_device(wdd);
if (ret)
goto out_disable_pclk;
dw_wdt_dbgfs_init(dw_wdt);
return 0;
out_disable_pclk:
clk_disable_unprepare(dw_wdt->pclk);
out_disable_clk:
clk_disable_unprepare(dw_wdt->clk);
return ret;
}
static int dw_wdt_drv_remove(struct platform_device *pdev)
{
struct dw_wdt *dw_wdt = platform_get_drvdata(pdev);
dw_wdt_dbgfs_clear(dw_wdt);
watchdog_unregister_device(&dw_wdt->wdd);
reset_control_assert(dw_wdt->rst);
clk_disable_unprepare(dw_wdt->pclk);
clk_disable_unprepare(dw_wdt->clk);
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id dw_wdt_of_match[] = {
{ .compatible = "snps,dw-wdt", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, dw_wdt_of_match);
#endif
static struct platform_driver dw_wdt_driver = {
.probe = dw_wdt_drv_probe,
.remove = dw_wdt_drv_remove,
.driver = {
.name = "dw_wdt",
.of_match_table = of_match_ptr(dw_wdt_of_match),
.pm = &dw_wdt_pm_ops,
},
};
module_platform_driver(dw_wdt_driver);
MODULE_AUTHOR("Jamie Iles");
MODULE_DESCRIPTION("Synopsys DesignWare Watchdog Driver");
MODULE_LICENSE("GPL");