Merge tag 'drivers-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
[pandora-kernel.git] / drivers / watchdog / orion_wdt.c
index 4981634..9b3c41d 100644 (file)
 #include <linux/kernel.h>
 #include <linux/platform_device.h>
 #include <linux/watchdog.h>
+#include <linux/interrupt.h>
 #include <linux/io.h>
-#include <linux/spinlock.h>
 #include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/of.h>
-#include <mach/bridge-regs.h>
+#include <linux/of_device.h>
+
+/* RSTOUT mask register physical address for Orion5x, Kirkwood and Dove */
+#define ORION_RSTOUT_MASK_OFFSET       0x20108
+
+/* Internal registers can be configured at any 1 MiB aligned address */
+#define INTERNAL_REGS_MASK             ~(SZ_1M - 1)
 
 /*
  * Watchdog timer block registers.
  */
 #define TIMER_CTRL             0x0000
-#define WDT_EN                 0x0010
-#define WDT_VAL                        0x0024
+#define TIMER_A370_STATUS      0x04
 
 #define WDT_MAX_CYCLE_COUNT    0xffffffff
-#define WDT_IN_USE             0
-#define WDT_OK_TO_CLOSE                1
 
-#define WDT_RESET_OUT_EN       BIT(1)
-#define WDT_INT_REQ            BIT(3)
+#define WDT_A370_RATIO_MASK(v) ((v) << 16)
+#define WDT_A370_RATIO_SHIFT   5
+#define WDT_A370_RATIO         (1 << WDT_A370_RATIO_SHIFT)
+
+#define WDT_AXP_FIXED_ENABLE_BIT BIT(10)
+#define WDT_A370_EXPIRED       BIT(31)
 
 static bool nowayout = WATCHDOG_NOWAYOUT;
 static int heartbeat = -1;             /* module parameter (seconds) */
-static unsigned int wdt_max_duration;  /* (seconds) */
-static struct clk *clk;
-static unsigned int wdt_tclk;
-static void __iomem *wdt_reg;
-static DEFINE_SPINLOCK(wdt_lock);
 
-static int orion_wdt_ping(struct watchdog_device *wdt_dev)
+struct orion_watchdog;
+
+struct orion_watchdog_data {
+       int wdt_counter_offset;
+       int wdt_enable_bit;
+       int rstout_enable_bit;
+       int (*clock_init)(struct platform_device *,
+                         struct orion_watchdog *);
+       int (*start)(struct watchdog_device *);
+};
+
+struct orion_watchdog {
+       struct watchdog_device wdt;
+       void __iomem *reg;
+       void __iomem *rstout;
+       unsigned long clk_rate;
+       struct clk *clk;
+       const struct orion_watchdog_data *data;
+};
+
+static int orion_wdt_clock_init(struct platform_device *pdev,
+                               struct orion_watchdog *dev)
 {
-       spin_lock(&wdt_lock);
+       int ret;
 
-       /* Reload watchdog duration */
-       writel(wdt_tclk * wdt_dev->timeout, wdt_reg + WDT_VAL);
+       dev->clk = clk_get(&pdev->dev, NULL);
+       if (IS_ERR(dev->clk))
+               return PTR_ERR(dev->clk);
+       ret = clk_prepare_enable(dev->clk);
+       if (ret) {
+               clk_put(dev->clk);
+               return ret;
+       }
 
-       spin_unlock(&wdt_lock);
+       dev->clk_rate = clk_get_rate(dev->clk);
        return 0;
 }
 
-static int orion_wdt_start(struct watchdog_device *wdt_dev)
+static int armada370_wdt_clock_init(struct platform_device *pdev,
+                                   struct orion_watchdog *dev)
 {
-       u32 reg;
+       int ret;
 
-       spin_lock(&wdt_lock);
+       dev->clk = clk_get(&pdev->dev, NULL);
+       if (IS_ERR(dev->clk))
+               return PTR_ERR(dev->clk);
+       ret = clk_prepare_enable(dev->clk);
+       if (ret) {
+               clk_put(dev->clk);
+               return ret;
+       }
+
+       /* Setup watchdog input clock */
+       atomic_io_modify(dev->reg + TIMER_CTRL,
+                       WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT),
+                       WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT));
+
+       dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
+       return 0;
+}
+
+static int armadaxp_wdt_clock_init(struct platform_device *pdev,
+                                  struct orion_watchdog *dev)
+{
+       int ret;
+
+       dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed");
+       if (IS_ERR(dev->clk))
+               return PTR_ERR(dev->clk);
+       ret = clk_prepare_enable(dev->clk);
+       if (ret) {
+               clk_put(dev->clk);
+               return ret;
+       }
+
+       /* Enable the fixed watchdog clock input */
+       atomic_io_modify(dev->reg + TIMER_CTRL,
+                        WDT_AXP_FIXED_ENABLE_BIT,
+                        WDT_AXP_FIXED_ENABLE_BIT);
+
+       dev->clk_rate = clk_get_rate(dev->clk);
+       return 0;
+}
+
+static int orion_wdt_ping(struct watchdog_device *wdt_dev)
+{
+       struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
+       /* Reload watchdog duration */
+       writel(dev->clk_rate * wdt_dev->timeout,
+              dev->reg + dev->data->wdt_counter_offset);
+       return 0;
+}
+
+static int armada370_start(struct watchdog_device *wdt_dev)
+{
+       struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 
        /* Set watchdog duration */
-       writel(wdt_tclk * wdt_dev->timeout, wdt_reg + WDT_VAL);
+       writel(dev->clk_rate * wdt_dev->timeout,
+              dev->reg + dev->data->wdt_counter_offset);
 
-       /* Clear watchdog timer interrupt */
-       writel(~WDT_INT_REQ, BRIDGE_CAUSE);
+       /* Clear the watchdog expiration bit */
+       atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
 
        /* Enable watchdog timer */
-       reg = readl(wdt_reg + TIMER_CTRL);
-       reg |= WDT_EN;
-       writel(reg, wdt_reg + TIMER_CTRL);
+       atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
+                                               dev->data->wdt_enable_bit);
+
+       atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit,
+                                     dev->data->rstout_enable_bit);
+       return 0;
+}
+
+static int orion_start(struct watchdog_device *wdt_dev)
+{
+       struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
+
+       /* Set watchdog duration */
+       writel(dev->clk_rate * wdt_dev->timeout,
+              dev->reg + dev->data->wdt_counter_offset);
+
+       /* Enable watchdog timer */
+       atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
+                                               dev->data->wdt_enable_bit);
 
        /* Enable reset on watchdog */
-       reg = readl(RSTOUTn_MASK);
-       reg |= WDT_RESET_OUT_EN;
-       writel(reg, RSTOUTn_MASK);
+       atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit,
+                                     dev->data->rstout_enable_bit);
 
-       spin_unlock(&wdt_lock);
        return 0;
 }
 
-static int orion_wdt_stop(struct watchdog_device *wdt_dev)
+static int orion_wdt_start(struct watchdog_device *wdt_dev)
 {
-       u32 reg;
+       struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 
-       spin_lock(&wdt_lock);
+       /* There are some per-SoC quirks to handle */
+       return dev->data->start(wdt_dev);
+}
+
+static int orion_wdt_stop(struct watchdog_device *wdt_dev)
+{
+       struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
 
        /* Disable reset on watchdog */
-       reg = readl(RSTOUTn_MASK);
-       reg &= ~WDT_RESET_OUT_EN;
-       writel(reg, RSTOUTn_MASK);
+       atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, 0);
 
        /* Disable watchdog timer */
-       reg = readl(wdt_reg + TIMER_CTRL);
-       reg &= ~WDT_EN;
-       writel(reg, wdt_reg + TIMER_CTRL);
+       atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
 
-       spin_unlock(&wdt_lock);
        return 0;
 }
 
-static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
+static int orion_wdt_enabled(struct orion_watchdog *dev)
 {
-       unsigned int time_left;
+       bool enabled, running;
+
+       enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
+       running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
 
-       spin_lock(&wdt_lock);
-       time_left = readl(wdt_reg + WDT_VAL) / wdt_tclk;
-       spin_unlock(&wdt_lock);
+       return enabled && running;
+}
 
-       return time_left;
+static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
+{
+       struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
+       return readl(dev->reg + dev->data->wdt_counter_offset) / dev->clk_rate;
 }
 
 static int orion_wdt_set_timeout(struct watchdog_device *wdt_dev,
@@ -136,68 +239,188 @@ static const struct watchdog_ops orion_wdt_ops = {
        .get_timeleft = orion_wdt_get_timeleft,
 };
 
-static struct watchdog_device orion_wdt = {
-       .info = &orion_wdt_info,
-       .ops = &orion_wdt_ops,
-       .min_timeout = 1,
+static irqreturn_t orion_wdt_irq(int irq, void *devid)
+{
+       panic("Watchdog Timeout");
+       return IRQ_HANDLED;
+}
+
+/*
+ * The original devicetree binding for this driver specified only
+ * one memory resource, so in order to keep DT backwards compatibility
+ * we try to fallback to a hardcoded register address, if the resource
+ * is missing from the devicetree.
+ */
+static void __iomem *orion_wdt_ioremap_rstout(struct platform_device *pdev,
+                                             phys_addr_t internal_regs)
+{
+       struct resource *res;
+       phys_addr_t rstout;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+       if (res)
+               return devm_ioremap(&pdev->dev, res->start,
+                                   resource_size(res));
+
+       /* This workaround works only for "orion-wdt", DT-enabled */
+       if (!of_device_is_compatible(pdev->dev.of_node, "marvell,orion-wdt"))
+               return NULL;
+
+       rstout = internal_regs + ORION_RSTOUT_MASK_OFFSET;
+
+       WARN(1, FW_BUG "falling back to harcoded RSTOUT reg %pa\n", &rstout);
+       return devm_ioremap(&pdev->dev, rstout, 0x4);
+}
+
+static const struct orion_watchdog_data orion_data = {
+       .rstout_enable_bit = BIT(1),
+       .wdt_enable_bit = BIT(4),
+       .wdt_counter_offset = 0x24,
+       .clock_init = orion_wdt_clock_init,
+       .start = orion_start,
+};
+
+static const struct orion_watchdog_data armada370_data = {
+       .rstout_enable_bit = BIT(8),
+       .wdt_enable_bit = BIT(8),
+       .wdt_counter_offset = 0x34,
+       .clock_init = armada370_wdt_clock_init,
+       .start = armada370_start,
 };
 
+static const struct orion_watchdog_data armadaxp_data = {
+       .rstout_enable_bit = BIT(8),
+       .wdt_enable_bit = BIT(8),
+       .wdt_counter_offset = 0x34,
+       .clock_init = armadaxp_wdt_clock_init,
+       .start = armada370_start,
+};
+
+static const struct of_device_id orion_wdt_of_match_table[] = {
+       {
+               .compatible = "marvell,orion-wdt",
+               .data = &orion_data,
+       },
+       {
+               .compatible = "marvell,armada-370-wdt",
+               .data = &armada370_data,
+       },
+       {
+               .compatible = "marvell,armada-xp-wdt",
+               .data = &armadaxp_data,
+       },
+       {},
+};
+MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
+
 static int orion_wdt_probe(struct platform_device *pdev)
 {
+       struct orion_watchdog *dev;
+       const struct of_device_id *match;
+       unsigned int wdt_max_duration;  /* (seconds) */
        struct resource *res;
-       int ret;
+       int ret, irq;
 
-       clk = devm_clk_get(&pdev->dev, NULL);
-       if (IS_ERR(clk)) {
-               dev_err(&pdev->dev, "Orion Watchdog missing clock\n");
-               return -ENODEV;
-       }
-       clk_prepare_enable(clk);
-       wdt_tclk = clk_get_rate(clk);
+       dev = devm_kzalloc(&pdev->dev, sizeof(struct orion_watchdog),
+                          GFP_KERNEL);
+       if (!dev)
+               return -ENOMEM;
+
+       match = of_match_device(orion_wdt_of_match_table, &pdev->dev);
+       if (!match)
+               /* Default legacy match */
+               match = &orion_wdt_of_match_table[0];
+
+       dev->wdt.info = &orion_wdt_info;
+       dev->wdt.ops = &orion_wdt_ops;
+       dev->wdt.min_timeout = 1;
+       dev->data = match->data;
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res)
                return -ENODEV;
-       wdt_reg = devm_ioremap(&pdev->dev, res->start, resource_size(res));
-       if (!wdt_reg)
-               return -ENOMEM;
 
-       wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk;
+       dev->reg = devm_ioremap(&pdev->dev, res->start,
+                              resource_size(res));
+       if (!dev->reg)
+               return -ENOMEM;
 
-       orion_wdt.timeout = wdt_max_duration;
-       orion_wdt.max_timeout = wdt_max_duration;
-       watchdog_init_timeout(&orion_wdt, heartbeat, &pdev->dev);
+       dev->rstout = orion_wdt_ioremap_rstout(pdev, res->start &
+                                                    INTERNAL_REGS_MASK);
+       if (!dev->rstout)
+               return -ENODEV;
 
-       watchdog_set_nowayout(&orion_wdt, nowayout);
-       ret = watchdog_register_device(&orion_wdt);
+       ret = dev->data->clock_init(pdev, dev);
        if (ret) {
-               clk_disable_unprepare(clk);
+               dev_err(&pdev->dev, "cannot initialize clock\n");
                return ret;
        }
 
+       wdt_max_duration = WDT_MAX_CYCLE_COUNT / dev->clk_rate;
+
+       dev->wdt.timeout = wdt_max_duration;
+       dev->wdt.max_timeout = wdt_max_duration;
+       watchdog_init_timeout(&dev->wdt, heartbeat, &pdev->dev);
+
+       platform_set_drvdata(pdev, &dev->wdt);
+       watchdog_set_drvdata(&dev->wdt, dev);
+
+       /*
+        * Let's make sure the watchdog is fully stopped, unless it's
+        * explicitly enabled. This may be the case if the module was
+        * removed and re-insterted, or if the bootloader explicitly
+        * set a running watchdog before booting the kernel.
+        */
+       if (!orion_wdt_enabled(dev))
+               orion_wdt_stop(&dev->wdt);
+
+       /* Request the IRQ only after the watchdog is disabled */
+       irq = platform_get_irq(pdev, 0);
+       if (irq > 0) {
+               /*
+                * Not all supported platforms specify an interrupt for the
+                * watchdog, so let's make it optional.
+                */
+               ret = devm_request_irq(&pdev->dev, irq, orion_wdt_irq, 0,
+                                      pdev->name, dev);
+               if (ret < 0) {
+                       dev_err(&pdev->dev, "failed to request IRQ\n");
+                       goto disable_clk;
+               }
+       }
+
+       watchdog_set_nowayout(&dev->wdt, nowayout);
+       ret = watchdog_register_device(&dev->wdt);
+       if (ret)
+               goto disable_clk;
+
        pr_info("Initial timeout %d sec%s\n",
-               orion_wdt.timeout, nowayout ? ", nowayout" : "");
+               dev->wdt.timeout, nowayout ? ", nowayout" : "");
        return 0;
+
+disable_clk:
+       clk_disable_unprepare(dev->clk);
+       clk_put(dev->clk);
+       return ret;
 }
 
 static int orion_wdt_remove(struct platform_device *pdev)
 {
-       watchdog_unregister_device(&orion_wdt);
-       clk_disable_unprepare(clk);
+       struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
+       struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
+
+       watchdog_unregister_device(wdt_dev);
+       clk_disable_unprepare(dev->clk);
+       clk_put(dev->clk);
        return 0;
 }
 
 static void orion_wdt_shutdown(struct platform_device *pdev)
 {
-       orion_wdt_stop(&orion_wdt);
+       struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
+       orion_wdt_stop(wdt_dev);
 }
 
-static const struct of_device_id orion_wdt_of_match_table[] = {
-       { .compatible = "marvell,orion-wdt", },
-       {},
-};
-MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
-
 static struct platform_driver orion_wdt_driver = {
        .probe          = orion_wdt_probe,
        .remove         = orion_wdt_remove,