[WDT] Add Synopsys DesignWare watchdog

This device is commonly used in SoCs.

Signed-off-by: GuEe-GUI <2991707448@qq.com>

components/drivers/watchdog/Kconfig

@@ -2,6 +2,13 @@ menuconfig RT_USING_WDT
     bool "Using Watch Dog device drivers"
     default n
 
+config RT_WDT_DW
+    bool "Synopsys DesignWare watchdog"
+    depends on RT_USING_DM
+    depends on RT_USING_WDT
+    depends on RT_USING_RESET
+    default n
+
 if RT_USING_DM && RT_USING_WDT
     osource "$(SOC_DM_WDT_DIR)/Kconfig"
 endif

components/drivers/watchdog/SConscript

@@ -11,6 +11,9 @@ CPPPATH = [cwd + '/../include']
 
 src = ['dev_watchdog.c']
 
+if GetDepend(['RT_WDT_DW']):
+    src += ['watchdog-dw.c']
+
 group = DefineGroup('DeviceDrivers', src, depend = [''], CPPPATH = CPPPATH)
 
 Return('group')

components/drivers/watchdog/watchdog-dw.c

@@ -0,0 +1,621 @@
+/*
+ * Copyright (c) 2006-2022, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2022-3-08      GuEe-GUI     the first version
+ */
+
+#include <rthw.h>
+#include <rtthread.h>
+#include <rtdevice.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      (1 << 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
+
+#define MSEC_PER_SEC 1000L
+
+enum dw_wdt_rmod
+{
+    DW_WDT_RMOD_RESET = 1,
+    DW_WDT_RMOD_IRQ
+};
+
+struct dw_wdt_timeout
+{
+    rt_uint32_t top_val;
+    rt_uint32_t sec;
+    rt_uint32_t msec;
+};
+
+struct dw_wdt
+{
+    rt_watchdog_t parent;
+
+    void *base;
+    int irq;
+    struct rt_clk *clk;
+    struct rt_reset_control *rstc;
+
+    rt_ubase_t rate;
+    enum dw_wdt_rmod rmod;
+    struct dw_wdt_timeout timeouts[DW_WDT_NUM_TOPS];
+    /* Save/Restore */
+    rt_uint32_t user;
+    rt_uint32_t timeout;
+    rt_uint32_t pretimeout;
+    rt_uint32_t max_hw_heartbeat_ms;
+
+    struct rt_device_notify pretimeout_notify;
+};
+
+#define raw_to_dw_wdt(raw) rt_container_of(raw, struct dw_wdt, parent)
+
+static const rt_uint32_t 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)
+};
+
+rt_inline int dw_wdt_is_enabled(struct dw_wdt *dw_wdt)
+{
+    return HWREG32(dw_wdt->base + 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)
+{
+    rt_uint32_t val = HWREG32(dw_wdt->base + 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;
+    }
+
+    HWREG32(dw_wdt->base + WDOG_CONTROL_REG_OFFSET) = val;
+
+    dw_wdt->rmod = rmod;
+}
+
+static rt_uint32_t dw_wdt_find_best_top(struct dw_wdt *dw_wdt, rt_uint32_t timeout, rt_uint32_t *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 rt_uint32_t dw_wdt_get_max_timeout_ms(struct dw_wdt *dw_wdt)
+{
+    rt_uint64_t msec;
+    struct dw_wdt_timeout *timeout = &dw_wdt->timeouts[DW_WDT_NUM_TOPS - 1];
+
+    msec = (rt_uint64_t)timeout->sec * MSEC_PER_SEC + timeout->msec;
+
+    return msec < RT_UINT32_MAX ? msec : RT_UINT32_MAX;
+}
+
+static rt_uint32_t dw_wdt_get_timeout(struct dw_wdt *dw_wdt)
+{
+    int idx;
+    int top_val = HWREG32(dw_wdt->base + WDOG_TIMEOUT_RANGE_REG_OFFSET) & 0xF;
+
+    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_keep_alive(struct dw_wdt *dw_wdt)
+{
+    HWREG32(dw_wdt->base + WDOG_COUNTER_RESTART_REG_OFFSET) = WDOG_COUNTER_RESTART_KICK_VALUE;
+
+    return 0;
+}
+
+static void dw_wdt_set_timeout(struct dw_wdt *dw_wdt, rt_uint32_t top_s)
+{
+    rt_uint32_t top_val;
+    rt_uint32_t timeout;
+
+    /*
+     * 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, RT_DIV_ROUND_UP(top_s, dw_wdt->rmod), &top_val);
+
+    if (dw_wdt->rmod == DW_WDT_RMOD_IRQ)
+    {
+        dw_wdt->pretimeout = timeout;
+    }
+    else
+    {
+        dw_wdt->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.
+     */
+    HWREG32(dw_wdt->base + WDOG_TIMEOUT_RANGE_REG_OFFSET) = top_val | top_val << WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT;
+
+    dw_wdt_keep_alive(dw_wdt);
+
+    /*
+     * 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 <= dw_wdt->max_hw_heartbeat_ms)
+    {
+        dw_wdt->timeout = timeout * dw_wdt->rmod;
+    }
+    else
+    {
+        dw_wdt->timeout = top_s;
+    }
+}
+
+static void dw_wdt_set_pretimeout(struct dw_wdt *dw_wdt, rt_uint32_t req)
+{
+    /*
+     * 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(dw_wdt, dw_wdt->timeout);
+}
+
+static void dw_wdt_arm_system_reset(struct dw_wdt *dw_wdt)
+{
+    rt_uint32_t val = HWREG32(dw_wdt->base + 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. */
+    HWREG32(dw_wdt->base + WDOG_CONTROL_REG_OFFSET) = val | WDOG_CONTROL_REG_WDT_EN_MASK;
+}
+
+static int dw_wdt_start(struct dw_wdt *dw_wdt)
+{
+    rt_clk_enable(dw_wdt->clk);
+
+    dw_wdt_set_timeout(dw_wdt, dw_wdt->timeout);
+    dw_wdt_keep_alive(dw_wdt);
+    dw_wdt_arm_system_reset(dw_wdt);
+
+    return 0;
+}
+
+static int dw_wdt_stop(struct dw_wdt *dw_wdt)
+{
+    /*
+     * 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.
+     */
+    rt_clk_disable(dw_wdt->clk);
+
+    rt_reset_control_assert(dw_wdt->rstc);
+    rt_reset_control_deassert(dw_wdt->rstc);
+
+    return 0;
+}
+
+static rt_uint32_t dw_wdt_get_timeleft(struct dw_wdt *dw_wdt)
+{
+    rt_uint32_t val, sec;
+
+    val = HWREG32(dw_wdt->base + WDOG_CURRENT_COUNT_REG_OFFSET);
+    sec = val / dw_wdt->rate;
+
+    if (dw_wdt->rmod == DW_WDT_RMOD_IRQ)
+    {
+        val = HWREG32(dw_wdt->base + WDOG_INTERRUPT_STATUS_REG_OFFSET);
+
+        if (!val)
+        {
+            sec += dw_wdt->pretimeout;
+        }
+    }
+
+    return sec;
+}
+
+static rt_err_t dw_wdt_init_timeouts(struct dw_wdt *dw_wdt)
+{
+    int val, tidx;
+    rt_uint64_t msec;
+    struct dw_wdt_timeout tout, *dst;
+    const rt_uint32_t *tops = dw_wdt_fix_tops;
+
+    /*
+     * Convert the specified TOPs into an array of watchdog timeouts. 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 = (rt_uint64_t)tops[val] * MSEC_PER_SEC;
+        rt_do_div(msec, dw_wdt->rate);
+        tout.msec = msec - ((rt_uint64_t)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
+            {
+                struct dw_wdt_timeout tmp = *dst;
+
+                *dst = tout;
+                tout = tmp;
+            }
+        }
+
+        dw_wdt->timeouts[val] = tout;
+    }
+
+    if (!dw_wdt->timeouts[DW_WDT_NUM_TOPS - 1].sec)
+    {
+        return -RT_ENOSYS;
+    }
+
+    return RT_EOK;
+}
+
+static rt_err_t dw_wdt_init(rt_watchdog_t *wdt)
+{
+    rt_err_t status = RT_EOK;
+    struct dw_wdt *dw_wdt = raw_to_dw_wdt(wdt);
+
+    /* Enable normal reset without pre-timeout by default. */
+    dw_wdt_update_mode(dw_wdt, DW_WDT_RMOD_RESET);
+
+    if (dw_wdt_init_timeouts(dw_wdt))
+    {
+        return -RT_ERROR;
+    }
+
+    dw_wdt->max_hw_heartbeat_ms = dw_wdt_get_max_timeout_ms(dw_wdt);
+
+    /*
+     * 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))
+    {
+        dw_wdt->timeout = dw_wdt_get_timeout(dw_wdt);
+    }
+    else
+    {
+        dw_wdt->timeout = DW_WDT_DEFAULT_SECONDS;
+    }
+
+    return status;
+}
+
+static rt_err_t dw_wdt_control(rt_watchdog_t *wdt, int cmd, void *args)
+{
+    rt_err_t status = RT_EOK;
+    struct dw_wdt *dw_wdt = raw_to_dw_wdt(wdt);
+
+    switch (cmd)
+    {
+    case RT_DEVICE_CTRL_WDT_GET_TIMEOUT:
+        *(rt_uint32_t *)args = dw_wdt_get_timeout(dw_wdt);
+        break;
+
+    case RT_DEVICE_CTRL_WDT_SET_TIMEOUT:
+        dw_wdt_set_timeout(dw_wdt, *(rt_uint32_t *)args);
+        break;
+
+    case RT_DEVICE_CTRL_WDT_GET_TIMELEFT:
+        *(rt_uint32_t *)args = dw_wdt_get_timeleft(dw_wdt);
+        break;
+
+    case RT_DEVICE_CTRL_WDT_KEEPALIVE:
+        dw_wdt_set_pretimeout(dw_wdt, dw_wdt->pretimeout);
+        dw_wdt_keep_alive(dw_wdt);
+        break;
+
+    case RT_DEVICE_CTRL_WDT_START:
+        dw_wdt_start(dw_wdt);
+        dw_wdt->user++;
+        break;
+
+    case RT_DEVICE_CTRL_WDT_STOP:
+        dw_wdt_stop(dw_wdt);
+        dw_wdt->user--;
+        break;
+
+    case RT_DEVICE_CTRL_NOTIFY_SET:
+        rt_hw_interrupt_mask(dw_wdt->irq);
+        if (args)
+        {
+            rt_memcpy(&dw_wdt->pretimeout_notify, args, sizeof(dw_wdt->pretimeout_notify));
+        }
+        else
+        {
+            rt_memset(&dw_wdt->pretimeout_notify, 0, sizeof(dw_wdt->pretimeout_notify));
+        }
+        rt_hw_interrupt_umask(dw_wdt->irq);
+        break;
+
+    default:
+        status = -RT_EINVAL;
+    }
+
+    return status;
+}
+
+static const struct rt_watchdog_ops dw_wdt_ops =
+{
+    .init = dw_wdt_init,
+    .control = dw_wdt_control,
+};
+
+#ifdef RT_USING_PM
+static rt_err_t dw_wdt_pm_suspend(const struct rt_device *device, rt_uint8_t mode)
+{
+    rt_watchdog_t *wdt = rt_container_of(device, rt_watchdog_t, parent);
+    struct dw_wdt *dw_wdt = raw_to_dw_wdt(wdt);
+
+    dw_wdt->timeout = dw_wdt_get_timeleft(dw_wdt) / dw_wdt->rate;
+    dw_wdt_stop(dw_wdt);
+
+    return RT_EOK;
+}
+
+static void dw_wdt_pm_resume(const struct rt_device *device, rt_uint8_t mode)
+{
+    rt_watchdog_t *wdt = rt_container_of(device, rt_watchdog_t, parent);
+    struct dw_wdt *dw_wdt = raw_to_dw_wdt(wdt);
+
+    if (!dw_wdt->user)
+    {
+        return;
+    }
+
+    if (!dw_wdt_init(wdt))
+    {
+        dw_wdt_start(dw_wdt);
+    }
+}
+
+static const struct rt_device_pm_ops dw_wdt_pm_ops =
+{
+    .suspend = dw_wdt_pm_suspend,
+    .resume = dw_wdt_pm_resume,
+};
+#endif /* RT_USING_PM */
+
+static void dw_wdt_isr(int irqno, void *param)
+{
+    struct dw_wdt *wdt = (struct dw_wdt *)param;
+
+    if (!HWREG32(wdt->base + WDOG_INTERRUPT_STATUS_REG_OFFSET))
+    {
+        return;
+    }
+
+    /* Clear the IRQ status (EOI) */
+    (void)HWREG32(wdt->base + WDOG_INTERRUPT_CLEAR_REG_OFFSET);
+
+    if (wdt->pretimeout_notify.notify)
+    {
+        wdt->pretimeout_notify.notify(wdt->pretimeout_notify.dev);
+    }
+}
+
+static void dw_wdt_free(struct dw_wdt *dw_wdt)
+{
+    if (dw_wdt->base)
+    {
+        rt_iounmap(dw_wdt->base);
+    }
+
+    if (!rt_is_err_or_null(dw_wdt->clk))
+    {
+        rt_clk_disable(dw_wdt->clk);
+    }
+
+    if (!rt_is_err_or_null(dw_wdt->rstc))
+    {
+        rt_reset_control_assert(dw_wdt->rstc);
+        rt_reset_control_put(dw_wdt->rstc);
+    }
+
+    rt_free(dw_wdt);
+}
+
+static rt_err_t dw_wdt_probe(struct rt_platform_device *pdev)
+{
+    rt_err_t err = RT_EOK;
+    const char *dev_name;
+    struct rt_device *dev = &pdev->parent;
+    struct dw_wdt *dw_wdt = rt_calloc(1, sizeof(*dw_wdt));
+
+    if (!dw_wdt)
+    {
+        return -RT_ENOMEM;
+    }
+
+    dw_wdt->base = rt_dm_dev_iomap(dev, 0);
+
+    if (!dw_wdt->base)
+    {
+        err = -RT_EIO;
+        goto _free_res;
+    }
+
+    dw_wdt->irq = rt_dm_dev_get_irq(dev, 0);
+
+    if (dw_wdt->irq < 0)
+    {
+        err = dw_wdt->irq;
+        goto _free_res;
+    }
+
+    dw_wdt->clk = rt_clk_get_by_name(dev, "pclk");
+
+    if (rt_is_err(dw_wdt->clk))
+    {
+        dw_wdt->clk = rt_clk_get_by_index(dev, 0);
+
+        if (rt_is_err(dw_wdt->clk))
+        {
+            err = rt_ptr_err(dw_wdt->clk);
+            goto _free_res;
+        }
+    }
+
+    dw_wdt->rstc = rt_reset_control_get_by_index(dev, 0);
+
+    if (rt_is_err(dw_wdt->rstc))
+    {
+        err = rt_ptr_err(dw_wdt->rstc);
+        goto _free_res;
+    }
+
+    rt_reset_control_deassert(dw_wdt->rstc);
+
+    dev->user_data = dw_wdt;
+
+    dw_wdt->rate = rt_clk_get_rate(dw_wdt->clk);
+    dw_wdt->parent.ops = &dw_wdt_ops;
+
+    rt_dm_dev_set_name_auto(&dw_wdt->parent.parent, "wdt");
+    dev_name = rt_dm_dev_get_name(&dw_wdt->parent.parent);
+
+    rt_hw_interrupt_install(dw_wdt->irq, dw_wdt_isr, dw_wdt, dev_name);
+    rt_hw_interrupt_umask(dw_wdt->irq);
+
+#ifdef RT_USING_PM
+    rt_pm_device_register(&dw_wdt->parent.parent, &dw_wdt_pm_ops);
+#endif
+
+    rt_hw_watchdog_register(&dw_wdt->parent, dev_name, 0, dw_wdt);
+
+    return RT_EOK;
+
+_free_res:
+    dw_wdt_free(dw_wdt);
+
+    return err;
+}
+
+static rt_err_t dw_wdt_remove(struct rt_platform_device *pdev)
+{
+    struct dw_wdt *dw_wdt = pdev->parent.user_data;
+
+    rt_hw_interrupt_mask(dw_wdt->irq);
+    rt_pic_detach_irq(dw_wdt->irq, dw_wdt);
+
+#ifdef RT_USING_PM
+    rt_pm_device_unregister(&dw_wdt->parent.parent);
+#endif
+
+    rt_device_unregister(&dw_wdt->parent.parent);
+
+    dw_wdt_free(dw_wdt);
+
+    return RT_EOK;
+}
+
+static const struct rt_ofw_node_id dw_wdt_ofw_ids[] =
+{
+    { .compatible = "snps,dw-wdt" },
+    { /* sentinel */ }
+};
+
+static struct rt_platform_driver dw_wdt_driver =
+{
+    .name = "dw-wdt",
+    .ids = dw_wdt_ofw_ids,
+
+    .probe = dw_wdt_probe,
+    .remove = dw_wdt_remove,
+};
+RT_PLATFORM_DRIVER_EXPORT(dw_wdt_driver);