1 files changed, 142 insertions, 59 deletions

diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c
index 780971318810..dfaac5995c84 100644
--- a/drivers/watchdog/qcom-wdt.c
+++ b/drivers/watchdog/qcom-wdt.c
@@ -1,24 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2014, The Linux Foundation. All rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 and
- * only version 2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
  */
+#include <linux/bits.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/watchdog.h>
-#include <linux/of_device.h>
 
 enum wdt_reg {
 	WDT_RST,
@@ -28,6 +20,8 @@ enum wdt_reg {
 	WDT_BITE_TIME,
 };
 
+#define QCOM_WDT_ENABLE		BIT(0)
+
 static const u32 reg_offset_data_apcs_tmr[] = {
 	[WDT_RST] = 0x38,
 	[WDT_EN] = 0x40,
@@ -44,9 +38,14 @@ static const u32 reg_offset_data_kpss[] = {
 	[WDT_BITE_TIME] = 0x14,
 };
 
+struct qcom_wdt_match_data {
+	const u32 *offset;
+	bool pretimeout;
+	u32 max_tick_count;
+};
+
 struct qcom_wdt {
 	struct watchdog_device	wdd;
-	struct clk		*clk;
 	unsigned long		rate;
 	void __iomem		*base;
 	const u32		*layout;
@@ -63,15 +62,25 @@ struct qcom_wdt *to_qcom_wdt(struct watchdog_device *wdd)
 	return container_of(wdd, struct qcom_wdt, wdd);
 }
 
+static irqreturn_t qcom_wdt_isr(int irq, void *arg)
+{
+	struct watchdog_device *wdd = arg;
+
+	watchdog_notify_pretimeout(wdd);
+
+	return IRQ_HANDLED;
+}
+
 static int qcom_wdt_start(struct watchdog_device *wdd)
 {
 	struct qcom_wdt *wdt = to_qcom_wdt(wdd);
+	unsigned int bark = wdd->timeout - wdd->pretimeout;
 
 	writel(0, wdt_addr(wdt, WDT_EN));
 	writel(1, wdt_addr(wdt, WDT_RST));
-	writel(wdd->timeout * wdt->rate, wdt_addr(wdt, WDT_BARK_TIME));
+	writel(bark * wdt->rate, wdt_addr(wdt, WDT_BARK_TIME));
 	writel(wdd->timeout * wdt->rate, wdt_addr(wdt, WDT_BITE_TIME));
-	writel(1, wdt_addr(wdt, WDT_EN));
+	writel(QCOM_WDT_ENABLE, wdt_addr(wdt, WDT_EN));
 	return 0;
 }
 
@@ -98,6 +107,13 @@ static int qcom_wdt_set_timeout(struct watchdog_device *wdd,
 	return qcom_wdt_start(wdd);
 }
 
+static int qcom_wdt_set_pretimeout(struct watchdog_device *wdd,
+				   unsigned int timeout)
+{
+	wdd->pretimeout = timeout;
+	return qcom_wdt_start(wdd);
+}
+
 static int qcom_wdt_restart(struct watchdog_device *wdd, unsigned long action,
 			    void *data)
 {
@@ -114,22 +130,30 @@ static int qcom_wdt_restart(struct watchdog_device *wdd, unsigned long action,
 	writel(1, wdt_addr(wdt, WDT_RST));
 	writel(timeout, wdt_addr(wdt, WDT_BARK_TIME));
 	writel(timeout, wdt_addr(wdt, WDT_BITE_TIME));
-	writel(1, wdt_addr(wdt, WDT_EN));
+	writel(QCOM_WDT_ENABLE, wdt_addr(wdt, WDT_EN));
 
 	/*
 	 * Actually make sure the above sequence hits hardware before sleeping.
 	 */
 	wmb();
 
-	msleep(150);
+	mdelay(150);
 	return 0;
 }
 
+static int qcom_wdt_is_running(struct watchdog_device *wdd)
+{
+	struct qcom_wdt *wdt = to_qcom_wdt(wdd);
+
+	return (readl(wdt_addr(wdt, WDT_EN)) & QCOM_WDT_ENABLE);
+}
+
 static const struct watchdog_ops qcom_wdt_ops = {
 	.start		= qcom_wdt_start,
 	.stop		= qcom_wdt_stop,
 	.ping		= qcom_wdt_ping,
 	.set_timeout	= qcom_wdt_set_timeout,
+	.set_pretimeout	= qcom_wdt_set_pretimeout,
 	.restart        = qcom_wdt_restart,
 	.owner		= THIS_MODULE,
 };
@@ -142,22 +166,51 @@ static const struct watchdog_info qcom_wdt_info = {
 	.identity	= KBUILD_MODNAME,
 };
 
+static const struct watchdog_info qcom_wdt_pt_info = {
+	.options	= WDIOF_KEEPALIVEPING
+			| WDIOF_MAGICCLOSE
+			| WDIOF_SETTIMEOUT
+			| WDIOF_PRETIMEOUT
+			| WDIOF_CARDRESET,
+	.identity	= KBUILD_MODNAME,
+};
+
+static const struct qcom_wdt_match_data match_data_apcs_tmr = {
+	.offset = reg_offset_data_apcs_tmr,
+	.pretimeout = false,
+	.max_tick_count = 0x10000000U,
+};
+
+static const struct qcom_wdt_match_data match_data_ipq5424 = {
+	.offset = reg_offset_data_kpss,
+	.pretimeout = true,
+	.max_tick_count = 0xFFFFFU,
+};
+
+static const struct qcom_wdt_match_data match_data_kpss = {
+	.offset = reg_offset_data_kpss,
+	.pretimeout = true,
+	.max_tick_count = 0xFFFFFU,
+};
+
 static int qcom_wdt_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct qcom_wdt *wdt;
 	struct resource *res;
-	struct device_node *np = pdev->dev.of_node;
-	const u32 *regs;
+	struct device_node *np = dev->of_node;
+	const struct qcom_wdt_match_data *data;
 	u32 percpu_offset;
-	int ret;
+	int irq, ret;
+	struct clk *clk;
 
-	regs = of_device_get_match_data(&pdev->dev);
-	if (!regs) {
-		dev_err(&pdev->dev, "Unsupported QCOM WDT module\n");
+	data = of_device_get_match_data(dev);
+	if (!data) {
+		dev_err(dev, "Unsupported QCOM WDT module\n");
 		return -ENODEV;
 	}
 
-	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
+	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
 	if (!wdt)
 		return -ENOMEM;
 
@@ -172,20 +225,14 @@ static int qcom_wdt_probe(struct platform_device *pdev)
 	res->start += percpu_offset;
 	res->end += percpu_offset;
 
-	wdt->base = devm_ioremap_resource(&pdev->dev, res);
+	wdt->base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(wdt->base))
 		return PTR_ERR(wdt->base);
 
-	wdt->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(wdt->clk)) {
-		dev_err(&pdev->dev, "failed to get input clock\n");
-		return PTR_ERR(wdt->clk);
-	}
-
-	ret = clk_prepare_enable(wdt->clk);
-	if (ret) {
-		dev_err(&pdev->dev, "failed to setup clock\n");
-		return ret;
+	clk = devm_clk_get_enabled(dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(dev, "failed to get input clock\n");
+		return PTR_ERR(clk);
 	}
 
 	/*
@@ -196,20 +243,35 @@ static int qcom_wdt_probe(struct platform_device *pdev)
 	 * that it would bite before a second elapses it's usefulness is
 	 * limited.  Bail if this is the case.
 	 */
-	wdt->rate = clk_get_rate(wdt->clk);
+	wdt->rate = clk_get_rate(clk);
 	if (wdt->rate == 0 ||
-	    wdt->rate > 0x10000000U) {
-		dev_err(&pdev->dev, "invalid clock rate\n");
-		ret = -EINVAL;
-		goto err_clk_unprepare;
+	    wdt->rate > data->max_tick_count) {
+		dev_err(dev, "invalid clock rate\n");
+		return -EINVAL;
+	}
+
+	/* check if there is pretimeout support */
+	irq = platform_get_irq_optional(pdev, 0);
+	if (data->pretimeout && irq > 0) {
+		ret = devm_request_irq(dev, irq, qcom_wdt_isr, 0,
+				       "wdt_bark", &wdt->wdd);
+		if (ret)
+			return ret;
+
+		wdt->wdd.info = &qcom_wdt_pt_info;
+		wdt->wdd.pretimeout = 1;
+	} else {
+		if (irq == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+
+		wdt->wdd.info = &qcom_wdt_info;
 	}
 
-	wdt->wdd.info = &qcom_wdt_info;
 	wdt->wdd.ops = &qcom_wdt_ops;
 	wdt->wdd.min_timeout = 1;
-	wdt->wdd.max_timeout = 0x10000000U / wdt->rate;
-	wdt->wdd.parent = &pdev->dev;
-	wdt->layout = regs;
+	wdt->wdd.max_timeout = data->max_tick_count / wdt->rate;
+	wdt->wdd.parent = dev;
+	wdt->layout = data->offset;
 
 	if (readl(wdt_addr(wdt, WDT_STS)) & 1)
 		wdt->wdd.bootstatus = WDIOF_CARDRESET;
@@ -220,45 +282,66 @@ static int qcom_wdt_probe(struct platform_device *pdev)
 	 * the max instead.
 	 */
 	wdt->wdd.timeout = min(wdt->wdd.max_timeout, 30U);
-	watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev);
+	watchdog_init_timeout(&wdt->wdd, 0, dev);
 
-	ret = watchdog_register_device(&wdt->wdd);
-	if (ret) {
-		dev_err(&pdev->dev, "failed to register watchdog\n");
-		goto err_clk_unprepare;
+	/*
+	 * If WDT is already running, call WDT start which
+	 * will stop the WDT, set timeouts as bootloader
+	 * might use different ones and set running bit
+	 * to inform the WDT subsystem to ping the WDT
+	 */
+	if (qcom_wdt_is_running(&wdt->wdd)) {
+		qcom_wdt_start(&wdt->wdd);
+		set_bit(WDOG_HW_RUNNING, &wdt->wdd.status);
 	}
 
+	ret = devm_watchdog_register_device(dev, &wdt->wdd);
+	if (ret)
+		return ret;
+
 	platform_set_drvdata(pdev, wdt);
 	return 0;
+}
+
+static int __maybe_unused qcom_wdt_suspend(struct device *dev)
+{
+	struct qcom_wdt *wdt = dev_get_drvdata(dev);
 
-err_clk_unprepare:
-	clk_disable_unprepare(wdt->clk);
-	return ret;
+	if (watchdog_active(&wdt->wdd))
+		qcom_wdt_stop(&wdt->wdd);
+
+	return 0;
 }
 
-static int qcom_wdt_remove(struct platform_device *pdev)
+static int __maybe_unused qcom_wdt_resume(struct device *dev)
 {
-	struct qcom_wdt *wdt = platform_get_drvdata(pdev);
+	struct qcom_wdt *wdt = dev_get_drvdata(dev);
+
+	if (watchdog_active(&wdt->wdd))
+		qcom_wdt_start(&wdt->wdd);
 
-	watchdog_unregister_device(&wdt->wdd);
-	clk_disable_unprepare(wdt->clk);
 	return 0;
 }
 
+static const struct dev_pm_ops qcom_wdt_pm_ops = {
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(qcom_wdt_suspend, qcom_wdt_resume)
+};
+
 static const struct of_device_id qcom_wdt_of_table[] = {
-	{ .compatible = "qcom,kpss-timer", .data = reg_offset_data_apcs_tmr },
-	{ .compatible = "qcom,scss-timer", .data = reg_offset_data_apcs_tmr },
-	{ .compatible = "qcom,kpss-wdt", .data = reg_offset_data_kpss },
+	{ .compatible = "qcom,apss-wdt-ipq5424", .data = &match_data_ipq5424 },
+	{ .compatible = "qcom,kpss-timer", .data = &match_data_apcs_tmr },
+	{ .compatible = "qcom,scss-timer", .data = &match_data_apcs_tmr },
+	{ .compatible = "qcom,kpss-wdt", .data = &match_data_kpss },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, qcom_wdt_of_table);
 
 static struct platform_driver qcom_watchdog_driver = {
 	.probe	= qcom_wdt_probe,
-	.remove	= qcom_wdt_remove,
 	.driver	= {
 		.name		= KBUILD_MODNAME,
 		.of_match_table	= qcom_wdt_of_table,
+		.pm		= &qcom_wdt_pm_ops,
 	},
 };
 module_platform_driver(qcom_watchdog_driver);