diff options
Diffstat (limited to 'drivers/watchdog/dw_wdt.c')
| -rw-r--r-- | drivers/watchdog/dw_wdt.c | 722 |
1 files changed, 722 insertions, 0 deletions
diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c new file mode 100644 index 000000000..61af5d133 --- /dev/null +++ b/drivers/watchdog/dw_wdt.c @@ -0,0 +1,722 @@ +// 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 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; +} + +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; +} + +static DEFINE_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_assert_rst; + + 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_assert_rst; + + dw_wdt_dbgfs_init(dw_wdt); + + return 0; + +out_assert_rst: + reset_control_assert(dw_wdt->rst); + +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 = pm_sleep_ptr(&dw_wdt_pm_ops), + }, +}; + +module_platform_driver(dw_wdt_driver); + +MODULE_AUTHOR("Jamie Iles"); +MODULE_DESCRIPTION("Synopsys DesignWare Watchdog Driver"); +MODULE_LICENSE("GPL"); |