Merge tag 'x86-urgent-2020-10-27' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux-2.6-microblaze.git] / drivers / watchdog / imx7ulp_wdt.c

diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c
index 7993c8c..922b603 100644 (file)
--- a/drivers/watchdog/imx7ulp_wdt.c
+++ b/drivers/watchdog/imx7ulp_wdt.c
@@ -5,6 +5,7 @@
 
 #include <linux/clk.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -21,6 +22,8 @@
 #define WDOG_CS_CLK            (LPO_CLK << LPO_CLK_SHIFT)
 #define WDOG_CS_EN             BIT(7)
 #define WDOG_CS_UPDATE         BIT(5)
+#define WDOG_CS_WAIT           BIT(1)
+#define WDOG_CS_STOP           BIT(0)
 
 #define WDOG_CNT       0x4
 #define WDOG_TOVAL     0x8
@@ -36,6 +39,7 @@
 #define DEFAULT_TIMEOUT        60
 #define MAX_TIMEOUT    128
 #define WDOG_CLOCK_RATE        1000
+#define WDOG_WAIT_TIMEOUT      20
 
 static bool nowayout = WATCHDOG_NOWAYOUT;
 module_param(nowayout, bool, 0000);
@@ -48,17 +52,40 @@ struct imx7ulp_wdt_device {
        struct clk *clk;
 };
 
-static void imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable)
+static int imx7ulp_wdt_wait(void __iomem *base, u32 mask)
+{
+       u32 val = readl(base + WDOG_CS);
+
+       if (!(val & mask) && readl_poll_timeout_atomic(base + WDOG_CS, val,
+                                                      val & mask, 0,
+                                                      WDOG_WAIT_TIMEOUT))
+               return -ETIMEDOUT;
+
+       return 0;
+}
+
+static int imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable)
 {
        struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
 
        u32 val = readl(wdt->base + WDOG_CS);
+       int ret;
 
+       local_irq_disable();
        writel(UNLOCK, wdt->base + WDOG_CNT);
+       ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK);
+       if (ret)
+               goto enable_out;
        if (enable)
                writel(val | WDOG_CS_EN, wdt->base + WDOG_CS);
        else
                writel(val & ~WDOG_CS_EN, wdt->base + WDOG_CS);
+       imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS);
+
+enable_out:
+       local_irq_enable();
+
+       return ret;
 }
 
 static bool imx7ulp_wdt_is_enabled(void __iomem *base)
@@ -79,17 +106,12 @@ static int imx7ulp_wdt_ping(struct watchdog_device *wdog)
 
 static int imx7ulp_wdt_start(struct watchdog_device *wdog)
 {
-
-       imx7ulp_wdt_enable(wdog, true);
-
-       return 0;
+       return imx7ulp_wdt_enable(wdog, true);
 }
 
 static int imx7ulp_wdt_stop(struct watchdog_device *wdog)
 {
-       imx7ulp_wdt_enable(wdog, false);
-
-       return 0;
+       return imx7ulp_wdt_enable(wdog, false);
 }
 
 static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog,
@@ -97,22 +119,37 @@ static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog,
 {
        struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
        u32 val = WDOG_CLOCK_RATE * timeout;
+       int ret;
 
+       local_irq_disable();
        writel(UNLOCK, wdt->base + WDOG_CNT);
+       ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK);
+       if (ret)
+               goto timeout_out;
        writel(val, wdt->base + WDOG_TOVAL);
+       imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS);
 
        wdog->timeout = timeout;
 
-       return 0;
+timeout_out:
+       local_irq_enable();
+
+       return ret;
 }
 
 static int imx7ulp_wdt_restart(struct watchdog_device *wdog,
                               unsigned long action, void *data)
 {
        struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
+       int ret;
+
+       ret = imx7ulp_wdt_enable(wdog, true);
+       if (ret)
+               return ret;
 
-       imx7ulp_wdt_enable(wdog, true);
-       imx7ulp_wdt_set_timeout(&wdt->wdd, 1);
+       ret = imx7ulp_wdt_set_timeout(&wdt->wdd, 1);
+       if (ret)
+               return ret;
 
        /* wait for wdog to fire */
        while (true)
@@ -136,19 +173,31 @@ static const struct watchdog_info imx7ulp_wdt_info = {
                    WDIOF_MAGICCLOSE,
 };
 
-static void imx7ulp_wdt_init(void __iomem *base, unsigned int timeout)
+static int imx7ulp_wdt_init(void __iomem *base, unsigned int timeout)
 {
        u32 val;
+       int ret;
 
+       local_irq_disable();
        /* unlock the wdog for reconfiguration */
        writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT);
        writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT);
+       ret = imx7ulp_wdt_wait(base, WDOG_CS_ULK);
+       if (ret)
+               goto init_out;
 
        /* set an initial timeout value in TOVAL */
        writel(timeout, base + WDOG_TOVAL);
        /* enable 32bit command sequence and reconfigure */
-       val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE;
+       val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE |
+             WDOG_CS_WAIT | WDOG_CS_STOP;
        writel(val, base + WDOG_CS);
+       imx7ulp_wdt_wait(base, WDOG_CS_RCS);
+
+init_out:
+       local_irq_enable();
+
+       return ret;
 }
 
 static void imx7ulp_wdt_action(void *data)
@@ -199,7 +248,9 @@ static int imx7ulp_wdt_probe(struct platform_device *pdev)
        watchdog_stop_on_reboot(wdog);
        watchdog_stop_on_unregister(wdog);
        watchdog_set_drvdata(wdog, imx7ulp_wdt);
-       imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * WDOG_CLOCK_RATE);
+       ret = imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * WDOG_CLOCK_RATE);
+       if (ret)
+               return ret;
 
        return devm_watchdog_register_device(dev, wdog);
 }