Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 318 insertions, 0 deletions

diff --git a/drivers/watchdog/lpc18xx_wdt.c b/drivers/watchdog/lpc18xx_wdt.c
new file mode 100644
index 000000000..60b6d74f2
--- /dev/null
+++ b/drivers/watchdog/lpc18xx_wdt.c
@@ -0,0 +1,318 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * NXP LPC18xx Watchdog Timer (WDT)
+ *
+ * Copyright (c) 2015 Ariel D'Alessandro <ariel@vanguardiasur.com>
+ *
+ * Notes
+ * -----
+ * The Watchdog consists of a fixed divide-by-4 clock pre-scaler and a 24-bit
+ * counter which decrements on every clock cycle.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+
+/* Registers */
+#define LPC18XX_WDT_MOD			0x00
+#define LPC18XX_WDT_MOD_WDEN		BIT(0)
+#define LPC18XX_WDT_MOD_WDRESET		BIT(1)
+
+#define LPC18XX_WDT_TC			0x04
+#define LPC18XX_WDT_TC_MIN		0xff
+#define LPC18XX_WDT_TC_MAX		0xffffff
+
+#define LPC18XX_WDT_FEED		0x08
+#define LPC18XX_WDT_FEED_MAGIC1		0xaa
+#define LPC18XX_WDT_FEED_MAGIC2		0x55
+
+#define LPC18XX_WDT_TV			0x0c
+
+/* Clock pre-scaler */
+#define LPC18XX_WDT_CLK_DIV		4
+
+/* Timeout values in seconds */
+#define LPC18XX_WDT_DEF_TIMEOUT		30U
+
+static int heartbeat;
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds (default="
+		 __MODULE_STRING(LPC18XX_WDT_DEF_TIMEOUT) ")");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+struct lpc18xx_wdt_dev {
+	struct watchdog_device	wdt_dev;
+	struct clk		*reg_clk;
+	struct clk		*wdt_clk;
+	unsigned long		clk_rate;
+	void __iomem		*base;
+	struct timer_list	timer;
+	spinlock_t		lock;
+};
+
+static int lpc18xx_wdt_feed(struct watchdog_device *wdt_dev)
+{
+	struct lpc18xx_wdt_dev *lpc18xx_wdt = watchdog_get_drvdata(wdt_dev);
+	unsigned long flags;
+
+	/*
+	 * An abort condition will occur if an interrupt happens during the feed
+	 * sequence.
+	 */
+	spin_lock_irqsave(&lpc18xx_wdt->lock, flags);
+	writel(LPC18XX_WDT_FEED_MAGIC1, lpc18xx_wdt->base + LPC18XX_WDT_FEED);
+	writel(LPC18XX_WDT_FEED_MAGIC2, lpc18xx_wdt->base + LPC18XX_WDT_FEED);
+	spin_unlock_irqrestore(&lpc18xx_wdt->lock, flags);
+
+	return 0;
+}
+
+static void lpc18xx_wdt_timer_feed(struct timer_list *t)
+{
+	struct lpc18xx_wdt_dev *lpc18xx_wdt = from_timer(lpc18xx_wdt, t, timer);
+	struct watchdog_device *wdt_dev = &lpc18xx_wdt->wdt_dev;
+
+	lpc18xx_wdt_feed(wdt_dev);
+
+	/* Use safe value (1/2 of real timeout) */
+	mod_timer(&lpc18xx_wdt->timer, jiffies +
+		  msecs_to_jiffies((wdt_dev->timeout * MSEC_PER_SEC) / 2));
+}
+
+/*
+ * Since LPC18xx Watchdog cannot be disabled in hardware, we must keep feeding
+ * it with a timer until userspace watchdog software takes over.
+ */
+static int lpc18xx_wdt_stop(struct watchdog_device *wdt_dev)
+{
+	struct lpc18xx_wdt_dev *lpc18xx_wdt = watchdog_get_drvdata(wdt_dev);
+
+	lpc18xx_wdt_timer_feed(&lpc18xx_wdt->timer);
+
+	return 0;
+}
+
+static void __lpc18xx_wdt_set_timeout(struct lpc18xx_wdt_dev *lpc18xx_wdt)
+{
+	unsigned int val;
+
+	val = DIV_ROUND_UP(lpc18xx_wdt->wdt_dev.timeout * lpc18xx_wdt->clk_rate,
+			   LPC18XX_WDT_CLK_DIV);
+	writel(val, lpc18xx_wdt->base + LPC18XX_WDT_TC);
+}
+
+static int lpc18xx_wdt_set_timeout(struct watchdog_device *wdt_dev,
+				   unsigned int new_timeout)
+{
+	struct lpc18xx_wdt_dev *lpc18xx_wdt = watchdog_get_drvdata(wdt_dev);
+
+	lpc18xx_wdt->wdt_dev.timeout = new_timeout;
+	__lpc18xx_wdt_set_timeout(lpc18xx_wdt);
+
+	return 0;
+}
+
+static unsigned int lpc18xx_wdt_get_timeleft(struct watchdog_device *wdt_dev)
+{
+	struct lpc18xx_wdt_dev *lpc18xx_wdt = watchdog_get_drvdata(wdt_dev);
+	unsigned int val;
+
+	val = readl(lpc18xx_wdt->base + LPC18XX_WDT_TV);
+	return (val * LPC18XX_WDT_CLK_DIV) / lpc18xx_wdt->clk_rate;
+}
+
+static int lpc18xx_wdt_start(struct watchdog_device *wdt_dev)
+{
+	struct lpc18xx_wdt_dev *lpc18xx_wdt = watchdog_get_drvdata(wdt_dev);
+	unsigned int val;
+
+	if (timer_pending(&lpc18xx_wdt->timer))
+		del_timer(&lpc18xx_wdt->timer);
+
+	val = readl(lpc18xx_wdt->base + LPC18XX_WDT_MOD);
+	val |= LPC18XX_WDT_MOD_WDEN;
+	val |= LPC18XX_WDT_MOD_WDRESET;
+	writel(val, lpc18xx_wdt->base + LPC18XX_WDT_MOD);
+
+	/*
+	 * Setting the WDEN bit in the WDMOD register is not sufficient to
+	 * enable the Watchdog. A valid feed sequence must be completed after
+	 * setting WDEN before the Watchdog is capable of generating a reset.
+	 */
+	lpc18xx_wdt_feed(wdt_dev);
+
+	return 0;
+}
+
+static int lpc18xx_wdt_restart(struct watchdog_device *wdt_dev,
+			       unsigned long action, void *data)
+{
+	struct lpc18xx_wdt_dev *lpc18xx_wdt = watchdog_get_drvdata(wdt_dev);
+	unsigned long flags;
+	int val;
+
+	/*
+	 * Incorrect feed sequence causes immediate watchdog reset if enabled.
+	 */
+	spin_lock_irqsave(&lpc18xx_wdt->lock, flags);
+
+	val = readl(lpc18xx_wdt->base + LPC18XX_WDT_MOD);
+	val |= LPC18XX_WDT_MOD_WDEN;
+	val |= LPC18XX_WDT_MOD_WDRESET;
+	writel(val, lpc18xx_wdt->base + LPC18XX_WDT_MOD);
+
+	writel(LPC18XX_WDT_FEED_MAGIC1, lpc18xx_wdt->base + LPC18XX_WDT_FEED);
+	writel(LPC18XX_WDT_FEED_MAGIC2, lpc18xx_wdt->base + LPC18XX_WDT_FEED);
+
+	writel(LPC18XX_WDT_FEED_MAGIC1, lpc18xx_wdt->base + LPC18XX_WDT_FEED);
+	writel(LPC18XX_WDT_FEED_MAGIC1, lpc18xx_wdt->base + LPC18XX_WDT_FEED);
+
+	spin_unlock_irqrestore(&lpc18xx_wdt->lock, flags);
+
+	return 0;
+}
+
+static const struct watchdog_info lpc18xx_wdt_info = {
+	.identity	= "NXP LPC18xx Watchdog",
+	.options	= WDIOF_SETTIMEOUT |
+			  WDIOF_KEEPALIVEPING |
+			  WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops lpc18xx_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= lpc18xx_wdt_start,
+	.stop		= lpc18xx_wdt_stop,
+	.ping		= lpc18xx_wdt_feed,
+	.set_timeout	= lpc18xx_wdt_set_timeout,
+	.get_timeleft	= lpc18xx_wdt_get_timeleft,
+	.restart        = lpc18xx_wdt_restart,
+};
+
+static void lpc18xx_clk_disable_unprepare(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static int lpc18xx_wdt_probe(struct platform_device *pdev)
+{
+	struct lpc18xx_wdt_dev *lpc18xx_wdt;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	lpc18xx_wdt = devm_kzalloc(dev, sizeof(*lpc18xx_wdt), GFP_KERNEL);
+	if (!lpc18xx_wdt)
+		return -ENOMEM;
+
+	lpc18xx_wdt->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(lpc18xx_wdt->base))
+		return PTR_ERR(lpc18xx_wdt->base);
+
+	lpc18xx_wdt->reg_clk = devm_clk_get(dev, "reg");
+	if (IS_ERR(lpc18xx_wdt->reg_clk)) {
+		dev_err(dev, "failed to get the reg clock\n");
+		return PTR_ERR(lpc18xx_wdt->reg_clk);
+	}
+
+	lpc18xx_wdt->wdt_clk = devm_clk_get(dev, "wdtclk");
+	if (IS_ERR(lpc18xx_wdt->wdt_clk)) {
+		dev_err(dev, "failed to get the wdt clock\n");
+		return PTR_ERR(lpc18xx_wdt->wdt_clk);
+	}
+
+	ret = clk_prepare_enable(lpc18xx_wdt->reg_clk);
+	if (ret) {
+		dev_err(dev, "could not prepare or enable sys clock\n");
+		return ret;
+	}
+	ret = devm_add_action_or_reset(dev, lpc18xx_clk_disable_unprepare,
+				       lpc18xx_wdt->reg_clk);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(lpc18xx_wdt->wdt_clk);
+	if (ret) {
+		dev_err(dev, "could not prepare or enable wdt clock\n");
+		return ret;
+	}
+	ret = devm_add_action_or_reset(dev, lpc18xx_clk_disable_unprepare,
+				       lpc18xx_wdt->wdt_clk);
+	if (ret)
+		return ret;
+
+	/* We use the clock rate to calculate timeouts */
+	lpc18xx_wdt->clk_rate = clk_get_rate(lpc18xx_wdt->wdt_clk);
+	if (lpc18xx_wdt->clk_rate == 0) {
+		dev_err(dev, "failed to get clock rate\n");
+		return -EINVAL;
+	}
+
+	lpc18xx_wdt->wdt_dev.info = &lpc18xx_wdt_info;
+	lpc18xx_wdt->wdt_dev.ops = &lpc18xx_wdt_ops;
+
+	lpc18xx_wdt->wdt_dev.min_timeout = DIV_ROUND_UP(LPC18XX_WDT_TC_MIN *
+				LPC18XX_WDT_CLK_DIV, lpc18xx_wdt->clk_rate);
+
+	lpc18xx_wdt->wdt_dev.max_timeout = (LPC18XX_WDT_TC_MAX *
+				LPC18XX_WDT_CLK_DIV) / lpc18xx_wdt->clk_rate;
+
+	lpc18xx_wdt->wdt_dev.timeout = min(lpc18xx_wdt->wdt_dev.max_timeout,
+					   LPC18XX_WDT_DEF_TIMEOUT);
+
+	spin_lock_init(&lpc18xx_wdt->lock);
+
+	lpc18xx_wdt->wdt_dev.parent = dev;
+	watchdog_set_drvdata(&lpc18xx_wdt->wdt_dev, lpc18xx_wdt);
+
+	watchdog_init_timeout(&lpc18xx_wdt->wdt_dev, heartbeat, dev);
+
+	__lpc18xx_wdt_set_timeout(lpc18xx_wdt);
+
+	timer_setup(&lpc18xx_wdt->timer, lpc18xx_wdt_timer_feed, 0);
+
+	watchdog_set_nowayout(&lpc18xx_wdt->wdt_dev, nowayout);
+	watchdog_set_restart_priority(&lpc18xx_wdt->wdt_dev, 128);
+
+	platform_set_drvdata(pdev, lpc18xx_wdt);
+
+	watchdog_stop_on_reboot(&lpc18xx_wdt->wdt_dev);
+	return devm_watchdog_register_device(dev, &lpc18xx_wdt->wdt_dev);
+}
+
+static int lpc18xx_wdt_remove(struct platform_device *pdev)
+{
+	struct lpc18xx_wdt_dev *lpc18xx_wdt = platform_get_drvdata(pdev);
+
+	dev_warn(&pdev->dev, "I quit now, hardware will probably reboot!\n");
+	del_timer_sync(&lpc18xx_wdt->timer);
+
+	return 0;
+}
+
+static const struct of_device_id lpc18xx_wdt_match[] = {
+	{ .compatible = "nxp,lpc1850-wwdt" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, lpc18xx_wdt_match);
+
+static struct platform_driver lpc18xx_wdt_driver = {
+	.driver = {
+		.name = "lpc18xx-wdt",
+		.of_match_table	= lpc18xx_wdt_match,
+	},
+	.probe = lpc18xx_wdt_probe,
+	.remove = lpc18xx_wdt_remove,
+};
+module_platform_driver(lpc18xx_wdt_driver);
+
+MODULE_AUTHOR("Ariel D'Alessandro <ariel@vanguardiasur.com.ar>");
+MODULE_DESCRIPTION("NXP LPC18xx Watchdog Timer Driver");
+MODULE_LICENSE("GPL v2");