Initial import

1 files changed, 654 insertions, 0 deletions

diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c
new file mode 100644
index 000000000..ef0c628d5
--- /dev/null
+++ b/drivers/watchdog/orion_wdt.c
@@ -0,0 +1,654 @@
+/*
+ * drivers/watchdog/orion_wdt.c
+ *
+ * Watchdog driver for Orion/Kirkwood processors
+ *
+ * Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
+ *
+ * This file is licensed under  the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/of.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 TIMER_A370_STATUS	0x04
+
+#define WDT_MAX_CYCLE_COUNT	0xffffffff
+
+#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) */
+
+struct orion_watchdog;
+
+struct orion_watchdog_data {
+	int wdt_counter_offset;
+	int wdt_enable_bit;
+	int rstout_enable_bit;
+	int rstout_mask_bit;
+	int (*clock_init)(struct platform_device *,
+			  struct orion_watchdog *);
+	int (*enabled)(struct orion_watchdog *);
+	int (*start)(struct watchdog_device *);
+	int (*stop)(struct watchdog_device *);
+};
+
+struct orion_watchdog {
+	struct watchdog_device wdt;
+	void __iomem *reg;
+	void __iomem *rstout;
+	void __iomem *rstout_mask;
+	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)
+{
+	int ret;
+
+	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;
+	}
+
+	dev->clk_rate = clk_get_rate(dev->clk);
+	return 0;
+}
+
+static int armada370_wdt_clock_init(struct platform_device *pdev,
+				    struct orion_watchdog *dev)
+{
+	int ret;
+
+	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 armada375_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)) {
+		ret = clk_prepare_enable(dev->clk);
+		if (ret) {
+			clk_put(dev->clk);
+			return ret;
+		}
+
+		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;
+	}
+
+	/* Mandatory fallback for proper devicetree backward compatibility */
+	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;
+	}
+
+	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 armada375_start(struct watchdog_device *wdt_dev)
+{
+	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
+	u32 reg;
+
+	/* Set watchdog duration */
+	writel(dev->clk_rate * wdt_dev->timeout,
+	       dev->reg + dev->data->wdt_counter_offset);
+
+	/* Clear the watchdog expiration bit */
+	atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
+
+	/* 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(dev->rstout);
+	reg |= dev->data->rstout_enable_bit;
+	writel(reg, dev->rstout);
+
+	atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, 0);
+	return 0;
+}
+
+static int armada370_start(struct watchdog_device *wdt_dev)
+{
+	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
+	u32 reg;
+
+	/* Set watchdog duration */
+	writel(dev->clk_rate * wdt_dev->timeout,
+	       dev->reg + dev->data->wdt_counter_offset);
+
+	/* Clear the watchdog expiration bit */
+	atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
+
+	/* 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(dev->rstout);
+	reg |= dev->data->rstout_enable_bit;
+	writel(reg, dev->rstout);
+	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 */
+	atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit,
+				      dev->data->rstout_enable_bit);
+
+	return 0;
+}
+
+static int orion_wdt_start(struct watchdog_device *wdt_dev)
+{
+	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
+
+	/* There are some per-SoC quirks to handle */
+	return dev->data->start(wdt_dev);
+}
+
+static int orion_stop(struct watchdog_device *wdt_dev)
+{
+	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
+
+	/* Disable reset on watchdog */
+	atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, 0);
+
+	/* Disable watchdog timer */
+	atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
+
+	return 0;
+}
+
+static int armada375_stop(struct watchdog_device *wdt_dev)
+{
+	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
+	u32 reg;
+
+	/* Disable reset on watchdog */
+	atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit,
+					   dev->data->rstout_mask_bit);
+	reg = readl(dev->rstout);
+	reg &= ~dev->data->rstout_enable_bit;
+	writel(reg, dev->rstout);
+
+	/* Disable watchdog timer */
+	atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
+
+	return 0;
+}
+
+static int armada370_stop(struct watchdog_device *wdt_dev)
+{
+	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
+	u32 reg;
+
+	/* Disable reset on watchdog */
+	reg = readl(dev->rstout);
+	reg &= ~dev->data->rstout_enable_bit;
+	writel(reg, dev->rstout);
+
+	/* Disable watchdog timer */
+	atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
+
+	return 0;
+}
+
+static int orion_wdt_stop(struct watchdog_device *wdt_dev)
+{
+	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
+
+	return dev->data->stop(wdt_dev);
+}
+
+static int orion_enabled(struct orion_watchdog *dev)
+{
+	bool enabled, running;
+
+	enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
+	running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
+
+	return enabled && running;
+}
+
+static int armada375_enabled(struct orion_watchdog *dev)
+{
+	bool masked, enabled, running;
+
+	masked = readl(dev->rstout_mask) & dev->data->rstout_mask_bit;
+	enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
+	running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
+
+	return !masked && enabled && running;
+}
+
+static int orion_wdt_enabled(struct watchdog_device *wdt_dev)
+{
+	struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
+
+	return dev->data->enabled(dev);
+}
+
+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,
+				 unsigned int timeout)
+{
+	wdt_dev->timeout = timeout;
+	return 0;
+}
+
+static const struct watchdog_info orion_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+	.identity = "Orion Watchdog",
+};
+
+static const struct watchdog_ops orion_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = orion_wdt_start,
+	.stop = orion_wdt_stop,
+	.ping = orion_wdt_ping,
+	.set_timeout = orion_wdt_set_timeout,
+	.get_timeleft = orion_wdt_get_timeleft,
+};
+
+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));
+
+	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,
+	.enabled = orion_enabled,
+	.start = orion_start,
+	.stop = orion_stop,
+};
+
+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,
+	.enabled = orion_enabled,
+	.start = armada370_start,
+	.stop = armada370_stop,
+};
+
+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,
+	.enabled = orion_enabled,
+	.start = armada370_start,
+	.stop = armada370_stop,
+};
+
+static const struct orion_watchdog_data armada375_data = {
+	.rstout_enable_bit = BIT(8),
+	.rstout_mask_bit = BIT(10),
+	.wdt_enable_bit = BIT(8),
+	.wdt_counter_offset = 0x34,
+	.clock_init = armada375_wdt_clock_init,
+	.enabled = armada375_enabled,
+	.start = armada375_start,
+	.stop = armada375_stop,
+};
+
+static const struct orion_watchdog_data armada380_data = {
+	.rstout_enable_bit = BIT(8),
+	.rstout_mask_bit = BIT(10),
+	.wdt_enable_bit = BIT(8),
+	.wdt_counter_offset = 0x34,
+	.clock_init = armadaxp_wdt_clock_init,
+	.enabled = armada375_enabled,
+	.start = armada375_start,
+	.stop = armada375_stop,
+};
+
+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,
+	},
+	{
+		.compatible = "marvell,armada-375-wdt",
+		.data = &armada375_data,
+	},
+	{
+		.compatible = "marvell,armada-380-wdt",
+		.data = &armada380_data,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
+
+static int orion_wdt_get_regs(struct platform_device *pdev,
+			      struct orion_watchdog *dev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+	dev->reg = devm_ioremap(&pdev->dev, res->start,
+				resource_size(res));
+	if (!dev->reg)
+		return -ENOMEM;
+
+	/* Each supported compatible has some RSTOUT register quirk */
+	if (of_device_is_compatible(node, "marvell,orion-wdt")) {
+
+		dev->rstout = orion_wdt_ioremap_rstout(pdev, res->start &
+						       INTERNAL_REGS_MASK);
+		if (!dev->rstout)
+			return -ENODEV;
+
+	} else if (of_device_is_compatible(node, "marvell,armada-370-wdt") ||
+		   of_device_is_compatible(node, "marvell,armada-xp-wdt")) {
+
+		/* Dedicated RSTOUT register, can be requested. */
+		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+		dev->rstout = devm_ioremap_resource(&pdev->dev, res);
+		if (IS_ERR(dev->rstout))
+			return PTR_ERR(dev->rstout);
+
+	} else if (of_device_is_compatible(node, "marvell,armada-375-wdt") ||
+		   of_device_is_compatible(node, "marvell,armada-380-wdt")) {
+
+		/* Dedicated RSTOUT register, can be requested. */
+		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+		dev->rstout = devm_ioremap_resource(&pdev->dev, res);
+		if (IS_ERR(dev->rstout))
+			return PTR_ERR(dev->rstout);
+
+		res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
+		if (!res)
+			return -ENODEV;
+		dev->rstout_mask = devm_ioremap(&pdev->dev, res->start,
+						resource_size(res));
+		if (!dev->rstout_mask)
+			return -ENOMEM;
+
+	} else {
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+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) */
+	int ret, irq;
+
+	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;
+
+	ret = orion_wdt_get_regs(pdev, dev);
+	if (ret)
+		return ret;
+
+	ret = dev->data->clock_init(pdev, dev);
+	if (ret) {
+		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->wdt))
+		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",
+		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)
+{
+	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)
+{
+	struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
+	orion_wdt_stop(wdt_dev);
+}
+
+static struct platform_driver orion_wdt_driver = {
+	.probe		= orion_wdt_probe,
+	.remove		= orion_wdt_remove,
+	.shutdown	= orion_wdt_shutdown,
+	.driver		= {
+		.name	= "orion_wdt",
+		.of_match_table = orion_wdt_of_match_table,
+	},
+};
+
+module_platform_driver(orion_wdt_driver);
+
+MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
+MODULE_DESCRIPTION("Orion Processor Watchdog");
+
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
+
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:orion_wdt");