watchdog: stm32: add pclk feature for stm32mp1

This patch adds compatible data to manage pclk clock by
compatible. Adds stm32mp1 support which requires pclk clock.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Acked-by: Alexandre TORGUE <alexandre.torgue@st.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

diff --git a/drivers/watchdog/stm32_iwdg.c b/drivers/watchdog/stm32_iwdg.c
index c97ad56..e00e3b3 100644 (file)
--- a/drivers/watchdog/stm32_iwdg.c
+++ b/drivers/watchdog/stm32_iwdg.c
@@ -11,12 +11,13 @@
 
 #include <linux/clk.h>
 #include <linux/delay.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/watchdog.h>
 
@@ -54,11 +55,15 @@
 #define TIMEOUT_US     100000
 #define SLEEP_US       1000
 
+#define HAS_PCLK       true
+
 struct stm32_iwdg {
        struct watchdog_device  wdd;
        void __iomem            *regs;
-       struct clk              *clk;
+       struct clk              *clk_lsi;
+       struct clk              *clk_pclk;
        unsigned int            rate;
+       bool                    has_pclk;
 };
 
 static inline u32 reg_read(void __iomem *base, u32 reg)
@@ -133,6 +138,44 @@ static int stm32_iwdg_set_timeout(struct watchdog_device *wdd,
        return 0;
 }
 
+static int stm32_iwdg_clk_init(struct platform_device *pdev,
+                              struct stm32_iwdg *wdt)
+{
+       u32 ret;
+
+       wdt->clk_lsi = devm_clk_get(&pdev->dev, "lsi");
+       if (IS_ERR(wdt->clk_lsi)) {
+               dev_err(&pdev->dev, "Unable to get lsi clock\n");
+               return PTR_ERR(wdt->clk_lsi);
+       }
+
+       /* optional peripheral clock */
+       if (wdt->has_pclk) {
+               wdt->clk_pclk = devm_clk_get(&pdev->dev, "pclk");
+               if (IS_ERR(wdt->clk_pclk)) {
+                       dev_err(&pdev->dev, "Unable to get pclk clock\n");
+                       return PTR_ERR(wdt->clk_pclk);
+               }
+
+               ret = clk_prepare_enable(wdt->clk_pclk);
+               if (ret) {
+                       dev_err(&pdev->dev, "Unable to prepare pclk clock\n");
+                       return ret;
+               }
+       }
+
+       ret = clk_prepare_enable(wdt->clk_lsi);
+       if (ret) {
+               dev_err(&pdev->dev, "Unable to prepare lsi clock\n");
+               clk_disable_unprepare(wdt->clk_pclk);
+               return ret;
+       }
+
+       wdt->rate = clk_get_rate(wdt->clk_lsi);
+
+       return 0;
+}
+
 static const struct watchdog_info stm32_iwdg_info = {
        .options        = WDIOF_SETTIMEOUT |
                          WDIOF_MAGICCLOSE |
@@ -147,49 +190,42 @@ static const struct watchdog_ops stm32_iwdg_ops = {
        .set_timeout    = stm32_iwdg_set_timeout,
 };
 
+static const struct of_device_id stm32_iwdg_of_match[] = {
+       { .compatible = "st,stm32-iwdg", .data = (void *)!HAS_PCLK },
+       { .compatible = "st,stm32mp1-iwdg", .data = (void *)HAS_PCLK },
+       { /* end node */ }
+};
+MODULE_DEVICE_TABLE(of, stm32_iwdg_of_match);
+
 static int stm32_iwdg_probe(struct platform_device *pdev)
 {
        struct watchdog_device *wdd;
+       const struct of_device_id *match;
        struct stm32_iwdg *wdt;
        struct resource *res;
-       void __iomem *regs;
-       struct clk *clk;
        int ret;
 
+       match = of_match_device(stm32_iwdg_of_match, &pdev->dev);
+       if (!match)
+               return -ENODEV;
+
+       wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
+       if (!wdt)
+               return -ENOMEM;
+
+       wdt->has_pclk = match->data;
+
        /* This is the timer base. */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-       regs = devm_ioremap_resource(&pdev->dev, res);
-       if (IS_ERR(regs)) {
+       wdt->regs = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(wdt->regs)) {
                dev_err(&pdev->dev, "Could not get resource\n");
-               return PTR_ERR(regs);
+               return PTR_ERR(wdt->regs);
        }
 
-       clk = devm_clk_get(&pdev->dev, NULL);
-       if (IS_ERR(clk)) {
-               dev_err(&pdev->dev, "Unable to get clock\n");
-               return PTR_ERR(clk);
-       }
-
-       ret = clk_prepare_enable(clk);
-       if (ret) {
-               dev_err(&pdev->dev, "Unable to prepare clock %p\n", clk);
+       ret = stm32_iwdg_clk_init(pdev, wdt);
+       if (ret)
                return ret;
-       }
-
-       /*
-        * Allocate our watchdog driver data, which has the
-        * struct watchdog_device nested within it.
-        */
-       wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
-       if (!wdt) {
-               ret = -ENOMEM;
-               goto err;
-       }
-
-       /* Initialize struct stm32_iwdg. */
-       wdt->regs = regs;
-       wdt->clk = clk;
-       wdt->rate = clk_get_rate(clk);
 
        /* Initialize struct watchdog_device. */
        wdd = &wdt->wdd;
@@ -217,7 +253,8 @@ static int stm32_iwdg_probe(struct platform_device *pdev)
 
        return 0;
 err:
-       clk_disable_unprepare(clk);
+       clk_disable_unprepare(wdt->clk_lsi);
+       clk_disable_unprepare(wdt->clk_pclk);
 
        return ret;
 }
@@ -227,23 +264,18 @@ static int stm32_iwdg_remove(struct platform_device *pdev)
        struct stm32_iwdg *wdt = platform_get_drvdata(pdev);
 
        watchdog_unregister_device(&wdt->wdd);
-       clk_disable_unprepare(wdt->clk);
+       clk_disable_unprepare(wdt->clk_lsi);
+       clk_disable_unprepare(wdt->clk_pclk);
 
        return 0;
 }
 
-static const struct of_device_id stm32_iwdg_of_match[] = {
-       { .compatible = "st,stm32-iwdg" },
-       { /* end node */ }
-};
-MODULE_DEVICE_TABLE(of, stm32_iwdg_of_match);
-
 static struct platform_driver stm32_iwdg_driver = {
        .probe          = stm32_iwdg_probe,
        .remove         = stm32_iwdg_remove,
        .driver = {
                .name   = "iwdg",
-               .of_match_table = stm32_iwdg_of_match,
+               .of_match_table = of_match_ptr(stm32_iwdg_of_match),
        },
 };
 module_platform_driver(stm32_iwdg_driver);