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>

1 files changed, 74 insertions, 42 deletions

diff --git a/drivers/watchdog/stm32_iwdg.c b/drivers/watchdog/stm32_iwdg.c
index c97ad5619cb0..e00e3b3526c6 100644
--- 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);