On 11/11/2013 10:34 PM, Leela Krishna Amudala wrote:
Add device tree support and use syscon regmap interface to configure
AUTOMATIC_WDT_RESET_DISABLE and MASK_WDT_RESET_REQUEST registers of PMU
to mask/unmask enable/disable of watchdog in probe and s2r scenarios.

If the driver didn't support devicetree before, why did it have #ifdef 
CONFIG_OF, and
why does its devicetree bindings file already exist ?

Seems to me the description does not match the patch; it appears that you are 
really
adding Exynos5 support to the driver.


Signed-off-by: Leela Krishna Amudala <[email protected]>
---
  .../devicetree/bindings/watchdog/samsung-wdt.txt   |   21 ++-
  drivers/watchdog/Kconfig                           |    1 +
  drivers/watchdog/s3c2410_wdt.c                     |  148 ++++++++++++++++++--
  3 files changed, 161 insertions(+), 9 deletions(-)

diff --git a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt 
b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
index 2aa486c..5dea363 100644
--- a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
+++ b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
@@ -5,10 +5,29 @@ after a preset amount of time during which the WDT reset 
event has not
  occurred.

  Required properties:
-- compatible : should be "samsung,s3c2410-wdt"
+- compatible : should be one among the following
+       (a) "samsung,s3c2410-wdt" for Exynos4 and previous SoCs
+       (b) "samsung,exynos5250-wdt" for Exynos5250
+       (c) "samsung,exynos5420-wdt" for Exynos5420
+
  - reg : base physical address of the controller and length of memory mapped
        region.
  - interrupts : interrupt number to the cpu.
+- samsung,syscon-phandle : reference to syscon node (This property required 
only
+       in case of compatible being "samsung,exynos5250-wdt" or 
"samsung,exynos5420-wdt".
+       In case of Exynos5250 and 5420 this property points to syscon node 
holding the PMU
+       base address)

  Optional properties:
  - timeout-sec : contains the watchdog timeout in seconds.
+
+Example:
+
+watchdog@101D0000 {
+       compatible = "samsung,exynos5250-wdt";
+       reg = <0x101D0000 0x100>;
+       interrupts = <0 42 0>;
+       clocks = <&clock 336>;
+       clock-names = "watchdog";
+       samsung,syscon-phandle = <&pmu_sys_reg>;
+};
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index d1d53f3..0d272ae 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -188,6 +188,7 @@ config S3C2410_WATCHDOG
        tristate "S3C2410 Watchdog"
        depends on HAVE_S3C2410_WATCHDOG
        select WATCHDOG_CORE
+       select MFD_SYSCON if ARCH_EXYNOS5
        help
          Watchdog timer block in the Samsung SoCs. This will reboot
          the system when the timer expires with the watchdog enabled.
diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
index 23aad7c..ccf755d 100644
--- a/drivers/watchdog/s3c2410_wdt.c
+++ b/drivers/watchdog/s3c2410_wdt.c
@@ -41,6 +41,8 @@
  #include <linux/slab.h>
  #include <linux/err.h>
  #include <linux/of.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>

  #define S3C2410_WTCON         0x00
  #define S3C2410_WTDAT         0x04
@@ -61,6 +63,10 @@
  #define CONFIG_S3C2410_WATCHDOG_ATBOOT                (0)
  #define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME  (15)

+#define WDT_DISABLE_REG_OFFSET         0x0408
+#define WDT_MASK_RESET_REG_OFFSET      0x040c
+#define QUIRK_NEEDS_PMU_CONFIG         (1 << 0)
+
  static bool nowayout  = WATCHDOG_NOWAYOUT;
  static int tmr_margin;
  static int tmr_atboot = CONFIG_S3C2410_WATCHDOG_ATBOOT;
@@ -84,6 +90,13 @@ MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to 
ignore reboots, "
                        "0 to reboot (default 0)");
  MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default 0)");

+struct s3c2410_wdt_variant {
+       int disable_reg;
+       int mask_reset_reg;
+       int mask_bit;
+       u32 quirks;
+};
+
  struct s3c2410_wdt {
        struct device           *dev;
        struct clk              *clock;
@@ -94,8 +107,50 @@ struct s3c2410_wdt {
        unsigned long           wtdat_save;
        struct watchdog_device  wdt_device;
        struct notifier_block   freq_transition;
+       struct s3c2410_wdt_variant *pmu_config;
+       struct regmap *pmureg;
+};
+
+static const struct s3c2410_wdt_variant pmu_config_s3c2410 = {
+       .quirks = 0
+};
+
+#ifdef CONFIG_OF
+static const struct s3c2410_wdt_variant pmu_config_5250  = {
+       .disable_reg = WDT_DISABLE_REG_OFFSET,
+       .mask_reset_reg = WDT_MASK_RESET_REG_OFFSET,
+       .mask_bit = 20,
+       .quirks = QUIRK_NEEDS_PMU_CONFIG
  };

+static const struct s3c2410_wdt_variant pmu_config_5420 = {
+       .disable_reg = WDT_DISABLE_REG_OFFSET,
+       .mask_reset_reg = WDT_MASK_RESET_REG_OFFSET,
+       .mask_bit = 0,
+       .quirks = QUIRK_NEEDS_PMU_CONFIG
+};
+
+static const struct of_device_id s3c2410_wdt_match[] = {
+       { .compatible = "samsung,s3c2410-wdt",
+         .data = &pmu_config_s3c2410 },
+       { .compatible = "samsung,exynos5250-wdt",
+         .data = &pmu_config_5250 },
+       { .compatible = "samsung,exynos5420-wdt",
+         .data = &pmu_config_5420 },
+       {},
+};
+MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
+#endif
+
+static const struct platform_device_id s3c2410_wdt_ids[] = {
+       {
+               .name = "s3c2410-wdt",
+               .driver_data = (unsigned long)&pmu_config_s3c2410,
+       },
+       {}
+};
+MODULE_DEVICE_TABLE(platform, s3c2410_wdt_ids);
+

What is this second device ID and MODULE_DEVICE_TABLE for ?
I assume it is to provide driver_data. If so, you should probably remove the
platform MODULE_ALIAS at the end of the driver.

  /* watchdog control routines */

  #define DBG(fmt, ...)                                 \
@@ -111,6 +166,30 @@ static inline struct s3c2410_wdt *freq_to_wdt(struct 
notifier_block *nb)
        return container_of(nb, struct s3c2410_wdt, freq_transition);
  }

+static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool 
mask)
+{
+       int ret;
+       u32 mask_val = 1 << wdt->pmu_config->mask_bit;
+       u32 val = 0;
+
+       if (mask)
+               val = mask_val;
+
+       ret = regmap_update_bits(wdt->pmureg,
+                       wdt->pmu_config->disable_reg,
+                       mask_val, val);
+       if (ret < 0)
+               return ret;
+
+       ret = regmap_update_bits(wdt->pmureg,
+                       wdt->pmu_config->mask_reset_reg,
+                       mask_val, val);
+       if (ret < 0)
+               return ret;
+
+       return 0;

The above code is identical to
        return ret;

+}
+
  static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
  {
        struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
@@ -332,6 +411,20 @@ static inline void s3c2410wdt_cpufreq_deregister(struct 
s3c2410_wdt *wdt)
  }
  #endif

+/* s3c2410_get_wdt_driver_data */
+static inline struct s3c2410_wdt_variant *
+get_wdt_drv_data(struct platform_device *pdev)
+{
+       if (pdev->dev.of_node) {
+               const struct of_device_id *match;
+               match = of_match_node(s3c2410_wdt_match, pdev->dev.of_node);
+               return (struct s3c2410_wdt_variant *)match->data;
+       } else {
+               return (struct s3c2410_wdt_variant *)
+                       platform_get_device_id(pdev)->driver_data;
+       }
+}
+
  static int s3c2410wdt_probe(struct platform_device *pdev)
  {
        struct device *dev;
@@ -354,6 +447,16 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
        spin_lock_init(&wdt->lock);
        wdt->wdt_device = s3c2410_wdd;

+       wdt->pmu_config = get_wdt_drv_data(pdev);
+       if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) {
+               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_resource(pdev, IORESOURCE_IRQ, 0);
        if (wdt_irq == NULL) {
                dev_err(dev, "no irq resource specified\n");
@@ -444,6 +547,14 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
                 (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis",
                 (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis");

+       if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) {

Might be easier to check for wdt->pmureg in all those secondary conditionals.

+               ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
+               if (ret < 0) {
+                       dev_warn(wdt->dev, "failed to update pmu register");

Is this a warning or an error ?

If it is (only) a warning, why do you bail out ?

On a side note, I am not sure if all those errors can really happen in practice.
Becasue if not, all you do is to increase code size with no real benefit.

+                       goto err_cpufreq;
+               }
+       }
+
        return 0;

   err_cpufreq:
@@ -459,8 +570,15 @@ static int s3c2410wdt_probe(struct platform_device *pdev)

  static int s3c2410wdt_remove(struct platform_device *dev)
  {
+       int ret;
        struct s3c2410_wdt *wdt = platform_get_drvdata(dev);

+       if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) {
+               ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
+               if (ret < 0)
+                       dev_warn(wdt->dev, "failed to update pmu register");
+       }
+
        watchdog_unregister_device(&wdt->wdt_device);

        s3c2410wdt_cpufreq_deregister(wdt);
@@ -473,8 +591,15 @@ static int s3c2410wdt_remove(struct platform_device *dev)

  static void s3c2410wdt_shutdown(struct platform_device *dev)
  {
+       int ret;
        struct s3c2410_wdt *wdt = platform_get_drvdata(dev);

+       if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) {
+               ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
+               if (ret < 0)
+                       dev_warn(wdt->dev, "failed to update pmu register");
+       }
+
        s3c2410wdt_stop(&wdt->wdt_device);
  }

@@ -482,12 +607,19 @@ static void s3c2410wdt_shutdown(struct platform_device 
*dev)

  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);

+       if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) {
+               ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
+               if (ret < 0)
+                       dev_warn(wdt->dev, "failed to update pmu register");
+       }
+
        /* Note that WTCNT doesn't need to be saved. */
        s3c2410wdt_stop(&wdt->wdt_device);

@@ -496,6 +628,7 @@ static int s3c2410wdt_suspend(struct device *dev)

  static int s3c2410wdt_resume(struct device *dev)
  {
+       int ret;
        struct s3c2410_wdt *wdt = dev_get_drvdata(dev);

        /* Restore watchdog state. */
@@ -503,6 +636,12 @@ static int s3c2410wdt_resume(struct device *dev)
        writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTCNT);/* Reset count */
        writel(wdt->wtcon_save, wdt->reg_base + S3C2410_WTCON);

+       if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) {
+               ret = s3c2410wdt_mask_and_disable_reset(wdt, false);
+               if (ret < 0)
+                       dev_warn(wdt->dev, "failed to update pmu register");
+       }
+
        dev_info(dev, "watchdog %sabled\n",
                (wdt->wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis");

@@ -513,18 +652,11 @@ static int s3c2410wdt_resume(struct device *dev)
  static SIMPLE_DEV_PM_OPS(s3c2410wdt_pm_ops, s3c2410wdt_suspend,
                        s3c2410wdt_resume);

-#ifdef CONFIG_OF
-static const struct of_device_id s3c2410_wdt_match[] = {
-       { .compatible = "samsung,s3c2410-wdt" },
-       {},
-};
-MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
-#endif
-
  static struct platform_driver s3c2410wdt_driver = {
        .probe          = s3c2410wdt_probe,
        .remove         = s3c2410wdt_remove,
        .shutdown       = s3c2410wdt_shutdown,
+       .id_table       = s3c2410_wdt_ids,
        .driver         = {
                .owner  = THIS_MODULE,
                .name   = "s3c2410-wdt",


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