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path: root/drivers/watchdog/s3c2410_wdt.c
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-rw-r--r--drivers/watchdog/s3c2410_wdt.c939
1 files changed, 939 insertions, 0 deletions
diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
new file mode 100644
index 000000000..d3fc8ed88
--- /dev/null
+++ b/drivers/watchdog/s3c2410_wdt.c
@@ -0,0 +1,939 @@
+// 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 EXYNOSAUTOV9_CLUSTER1_NONCPU_OUT 0x1520
+#define EXYNOSAUTOV9_CLUSTER1_NONCPU_INT_EN 0x1544
+
+#define EXYNOS850_CLUSTER0_WDTRESET_BIT 24
+#define EXYNOS850_CLUSTER1_WDTRESET_BIT 23
+#define EXYNOSAUTOV9_CLUSTER0_WDTRESET_BIT 25
+#define EXYNOSAUTOV9_CLUSTER1_WDTRESET_BIT 24
+
+/**
+ * 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 s3c2410_wdt_variant drv_data_exynosautov9_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 = EXYNOSAUTOV9_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_exynosautov9_cl1 = {
+ .mask_reset_reg = EXYNOSAUTOV9_CLUSTER1_NONCPU_INT_EN,
+ .mask_bit = 2,
+ .mask_reset_inv = true,
+ .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
+ .rst_stat_bit = EXYNOSAUTOV9_CLUSTER1_WDTRESET_BIT,
+ .cnt_en_reg = EXYNOSAUTOV9_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 },
+ { .compatible = "samsung,exynosautov9-wdt",
+ .data = &drv_data_exynosautov9_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/ExynosAutov9 driver data w.r.t. cluster index */
+ if (variant == &drv_data_exynos850_cl0 ||
+ variant == &drv_data_exynosautov9_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 variant;
+ case 1:
+ return (variant == &drv_data_exynos850_cl0) ?
+ &drv_data_exynos850_cl1 :
+ &drv_data_exynosautov9_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);
+}
+
+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;
+}
+
+static DEFINE_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 = pm_sleep_ptr(&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");