linux-watchdog 5.8-rc1 tag

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Merge tag 'linux-watchdog-5.8-rc1' of git://www.linux-watchdog.org/linux-watchdog

Pull watchdog updates from Wim Van Sebroeck:

 - add new arm_smc_wdt watchdog driver

 - da9062 and da9063 improvements

 - clarify documentation about stop() that became optional

 - document r8a7742 support

 - some overall fixes and improvements

* tag 'linux-watchdog-5.8-rc1' of git://www.linux-watchdog.org/linux-watchdog:
  watchdog: m54xx: Add missing include
  dt-bindings: watchdog: renesas,wdt: Document r8a7742 support
  watchdog: Fix runtime PM imbalance on error
  watchdog: riowd: remove unneeded semicolon
  watchdog: Add new arm_smc_wdt watchdog driver
  dt-bindings: watchdog: Add ARM smc wdt for mt8173 watchdog
  watchdog: imx2_wdt: update contact email
  watchdog: iTCO: fix link error
  watchdog: da9062: No need to ping manually before setting timeout
  watchdog: da9063: Make use of pre-configured timeout during probe
  watchdog: da9062: Initialize timeout during probe
  watchdog: clarify that stop() is optional
  watchdog: imx_sc_wdt: Fix reboot on crash
  watchdog: ts72xx_wdt: fix build error

Documentation/devicetree/bindings/watchdog/arm-smc-wdt.yaml

@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/watchdog/arm-smc-wdt.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM Secure Monitor Call based watchdog
+
+allOf:
+  - $ref: "watchdog.yaml#"
+
+maintainers:
+  - Julius Werner <jwerner@chromium.org>
+
+properties:
+  compatible:
+    enum:
+      - arm,smc-wdt
+  arm,smc-id:
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      The ATF smc function id used by the firmware.
+      Defaults to 0x82003D06 if unset.
+
+required:
+  - compatible
+
+examples:
+  - |
+    watchdog {
+      compatible = "arm,smc-wdt";
+      arm,smc-id = <0x82003D06>;
+      timeout-sec = <15>;
+    };
+
+...

Documentation/devicetree/bindings/watchdog/renesas,wdt.txt

@@ -5,6 +5,7 @@ Required properties:
 		fallback compatible string when compatible with the generic
 		version.
 	       Examples with soctypes are:
+		 - "renesas,r8a7742-wdt" (RZ/G1H)
 		 - "renesas,r8a7743-wdt" (RZ/G1M)
 		 - "renesas,r8a7744-wdt" (RZ/G1N)
 		 - "renesas,r8a7745-wdt" (RZ/G1E)

MAINTAINERS

@@ -1468,6 +1468,13 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/interrupt-controller/arm,vic.txt
 F:	drivers/irqchip/irq-vic.c
 
+ARM SMC WATCHDOG DRIVER
+M:	Julius Werner <jwerner@chromium.org>
+R:	Evan Benn <evanbenn@chromium.org>
+S:	Maintained
+F:	devicetree/bindings/watchdog/arm-smc-wdt.yaml
+F:	drivers/watchdog/arm_smc_wdt.c
+
 ARM SMMU DRIVERS
 M:	Will Deacon <will@kernel.org>
 R:	Robin Murphy <robin.murphy@arm.com>

arch/arm64/configs/defconfig

@@ -513,6 +513,7 @@ CONFIG_UNIPHIER_THERMAL=y
 CONFIG_WATCHDOG=y
 CONFIG_ARM_SP805_WATCHDOG=y
 CONFIG_ARM_SBSA_WATCHDOG=y
+CONFIG_ARM_SMC_WATCHDOG=y
 CONFIG_S3C2410_WATCHDOG=y
 CONFIG_DW_WATCHDOG=y
 CONFIG_SUNXI_WATCHDOG=m

drivers/watchdog/Kconfig

@@ -678,6 +678,7 @@ config TS4800_WATCHDOG
 config TS72XX_WATCHDOG
 	tristate "TS-72XX SBC Watchdog"
 	depends on MACH_TS72XX || COMPILE_TEST
+	select WATCHDOG_CORE
 	help
 	  Technologic Systems TS-7200, TS-7250 and TS-7260 boards have
 	  watchdog timer implemented in a external CPLD chip. Say Y here
@@ -867,6 +868,19 @@ config DIGICOLOR_WATCHDOG
 	  To compile this driver as a module, choose M here: the
 	  module will be called digicolor_wdt.
 
+config ARM_SMC_WATCHDOG
+	tristate "ARM Secure Monitor Call based watchdog support"
+	depends on ARM || ARM64
+	depends on OF
+	depends on HAVE_ARM_SMCCC
+	select WATCHDOG_CORE
+	help
+	  Say Y here to include support for a watchdog timer
+	  implemented by the EL3 Secure Monitor on ARM platforms.
+	  Requires firmware support.
+	  To compile this driver as a module, choose M here: the
+	  module will be called arm_smc_wdt.
+
 config LPC18XX_WATCHDOG
 	tristate "LPC18xx/43xx Watchdog"
 	depends on ARCH_LPC18XX || COMPILE_TEST

drivers/watchdog/Makefile

@@ -94,6 +94,7 @@ obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o
 obj-$(CONFIG_RTD119X_WATCHDOG) += rtd119x_wdt.o
 obj-$(CONFIG_SPRD_WATCHDOG) += sprd_wdt.o
 obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o
+obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o
 
 # X86 (i386 + ia64 + x86_64) Architecture
 obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o

drivers/watchdog/arm_smc_wdt.c

@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ARM Secure Monitor Call watchdog driver
+ *
+ * Copyright 2020 Google LLC.
+ * Julius Werner <jwerner@chromium.org>
+ * Based on mtk_wdt.c
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+#include <uapi/linux/psci.h>
+
+#define DRV_NAME		"arm_smc_wdt"
+#define DRV_VERSION		"1.0"
+
+enum smcwd_call {
+	SMCWD_INIT		= 0,
+	SMCWD_SET_TIMEOUT	= 1,
+	SMCWD_ENABLE		= 2,
+	SMCWD_PET		= 3,
+	SMCWD_GET_TIMELEFT	= 4,
+};
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static unsigned int timeout;
+
+static int smcwd_call(struct watchdog_device *wdd, enum smcwd_call call,
+		      unsigned long arg, struct arm_smccc_res *res)
+{
+	struct arm_smccc_res local_res;
+
+	if (!res)
+		res = &local_res;
+
+	arm_smccc_smc((u32)(uintptr_t)watchdog_get_drvdata(wdd), call, arg, 0,
+		      0, 0, 0, 0, res);
+
+	if (res->a0 == PSCI_RET_NOT_SUPPORTED)
+		return -ENODEV;
+	if (res->a0 == PSCI_RET_INVALID_PARAMS)
+		return -EINVAL;
+	if (res->a0 != PSCI_RET_SUCCESS)
+		return -EIO;
+	return 0;
+}
+
+static int smcwd_ping(struct watchdog_device *wdd)
+{
+	return smcwd_call(wdd, SMCWD_PET, 0, NULL);
+}
+
+static unsigned int smcwd_get_timeleft(struct watchdog_device *wdd)
+{
+	struct arm_smccc_res res;
+
+	smcwd_call(wdd, SMCWD_GET_TIMELEFT, 0, &res);
+	if (res.a0)
+		return 0;
+	return res.a1;
+}
+
+static int smcwd_set_timeout(struct watchdog_device *wdd, unsigned int timeout)
+{
+	int res;
+
+	res = smcwd_call(wdd, SMCWD_SET_TIMEOUT, timeout, NULL);
+	if (!res)
+		wdd->timeout = timeout;
+	return res;
+}
+
+static int smcwd_stop(struct watchdog_device *wdd)
+{
+	return smcwd_call(wdd, SMCWD_ENABLE, 0, NULL);
+}
+
+static int smcwd_start(struct watchdog_device *wdd)
+{
+	return smcwd_call(wdd, SMCWD_ENABLE, 1, NULL);
+}
+
+static const struct watchdog_info smcwd_info = {
+	.identity	= DRV_NAME,
+	.options	= WDIOF_SETTIMEOUT |
+			  WDIOF_KEEPALIVEPING |
+			  WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops smcwd_ops = {
+	.start		= smcwd_start,
+	.stop		= smcwd_stop,
+	.ping		= smcwd_ping,
+	.set_timeout	= smcwd_set_timeout,
+};
+
+static const struct watchdog_ops smcwd_timeleft_ops = {
+	.start		= smcwd_start,
+	.stop		= smcwd_stop,
+	.ping		= smcwd_ping,
+	.set_timeout	= smcwd_set_timeout,
+	.get_timeleft	= smcwd_get_timeleft,
+};
+
+static int smcwd_probe(struct platform_device *pdev)
+{
+	struct watchdog_device *wdd;
+	int err;
+	struct arm_smccc_res res;
+	u32 smc_func_id;
+
+	wdd = devm_kzalloc(&pdev->dev, sizeof(*wdd), GFP_KERNEL);
+	if (!wdd)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, wdd);
+
+	if (of_property_read_u32(pdev->dev.of_node, "arm,smc-id",
+				 &smc_func_id))
+		smc_func_id = 0x82003D06;
+	watchdog_set_drvdata(wdd, (void *)(uintptr_t)smc_func_id);
+
+	err = smcwd_call(wdd, SMCWD_INIT, 0, &res);
+	if (err < 0)
+		return err;
+
+	wdd->info = &smcwd_info;
+	/* get_timeleft is optional */
+	if (smcwd_call(wdd, SMCWD_GET_TIMELEFT, 0, NULL))
+		wdd->ops = &smcwd_ops;
+	else
+		wdd->ops = &smcwd_timeleft_ops;
+	wdd->timeout = res.a2;
+	wdd->max_timeout = res.a2;
+	wdd->min_timeout = res.a1;
+	wdd->parent = &pdev->dev;
+
+	watchdog_stop_on_reboot(wdd);
+	watchdog_stop_on_unregister(wdd);
+	watchdog_set_nowayout(wdd, nowayout);
+	watchdog_init_timeout(wdd, timeout, &pdev->dev);
+	err = smcwd_set_timeout(wdd, wdd->timeout);
+	if (err)
+		return err;
+
+	err = devm_watchdog_register_device(&pdev->dev, wdd);
+	if (err)
+		return err;
+
+	dev_info(&pdev->dev,
+		 "Watchdog registered (timeout=%d sec, nowayout=%d)\n",
+		 wdd->timeout, nowayout);
+
+	return 0;
+}
+
+static const struct of_device_id smcwd_dt_ids[] = {
+	{ .compatible = "arm,smc-wdt" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, smcwd_dt_ids);
+
+static struct platform_driver smcwd_driver = {
+	.probe		= smcwd_probe,
+	.driver		= {
+		.name		= DRV_NAME,
+		.of_match_table	= smcwd_dt_ids,
+	},
+};
+
+module_platform_driver(smcwd_driver);
+
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout, "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_AUTHOR("Julius Werner <jwerner@chromium.org>");
+MODULE_DESCRIPTION("ARM Secure Monitor Call Watchdog Driver");
+MODULE_VERSION(DRV_VERSION);

drivers/watchdog/da9062_wdt.c

@@ -35,6 +35,15 @@ struct da9062_watchdog {
 	bool use_sw_pm;
 };
 
+static unsigned int da9062_wdt_read_timeout(struct da9062_watchdog *wdt)
+{
+	unsigned int val;
+
+	regmap_read(wdt->hw->regmap, DA9062AA_CONTROL_D, &val);
+
+	return wdt_timeout[val & DA9062AA_TWDSCALE_MASK];
+}
+
 static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
 {
 	unsigned int i;
@@ -58,11 +67,6 @@ static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
 					      unsigned int regval)
 {
 	struct da9062 *chip = wdt->hw;
-	int ret;
-
-	ret = da9062_reset_watchdog_timer(wdt);
-	if (ret)
-		return ret;
 
 	regmap_update_bits(chip->regmap,
 				  DA9062AA_CONTROL_D,
@@ -183,7 +187,7 @@ MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
 static int da9062_wdt_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	int ret;
+	unsigned int timeout;
 	struct da9062 *chip;
 	struct da9062_watchdog *wdt;
 
@@ -213,11 +217,19 @@ static int da9062_wdt_probe(struct platform_device *pdev)
 	watchdog_set_drvdata(&wdt->wdtdev, wdt);
 	dev_set_drvdata(dev, &wdt->wdtdev);
 
-	ret = devm_watchdog_register_device(dev, &wdt->wdtdev);
-	if (ret < 0)
-		return ret;
+	timeout = da9062_wdt_read_timeout(wdt);
+	if (timeout)
+		wdt->wdtdev.timeout = timeout;
 
-	return da9062_wdt_ping(&wdt->wdtdev);
+	/* Set timeout from DT value if available */
+	watchdog_init_timeout(&wdt->wdtdev, 0, dev);
+
+	if (timeout) {
+		da9062_wdt_set_timeout(&wdt->wdtdev, wdt->wdtdev.timeout);
+		set_bit(WDOG_HW_RUNNING, &wdt->wdtdev.status);
+	}
+
+	return devm_watchdog_register_device(dev, &wdt->wdtdev);
 }
 
 static int __maybe_unused da9062_wdt_suspend(struct device *dev)

drivers/watchdog/da9063_wdt.c

@@ -46,15 +46,16 @@ static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
 }
 
 /*
- * Return 0 if watchdog is disabled, else non zero.
+ * Read the currently active timeout.
+ * Zero means the watchdog is disabled.
  */
-static unsigned int da9063_wdt_is_running(struct da9063 *da9063)
+static unsigned int da9063_wdt_read_timeout(struct da9063 *da9063)
 {
 	unsigned int val;
 
 	regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val);
 
-	return val & DA9063_TWDSCALE_MASK;
+	return wdt_timeout[val & DA9063_TWDSCALE_MASK];
 }
 
 static int da9063_wdt_disable_timer(struct da9063 *da9063)
@@ -191,6 +192,7 @@ static int da9063_wdt_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct da9063 *da9063;
 	struct watchdog_device *wdd;
+	unsigned int timeout;
 
 	if (!dev->parent)
 		return -EINVAL;
@@ -214,13 +216,19 @@ static int da9063_wdt_probe(struct platform_device *pdev)
 	watchdog_set_restart_priority(wdd, 128);
 	watchdog_set_drvdata(wdd, da9063);
 
-	/* Set default timeout, maybe override it with DT value, scale it */
 	wdd->timeout = DA9063_WDG_TIMEOUT;
+
+	/* Use pre-configured timeout if watchdog is already running. */
+	timeout = da9063_wdt_read_timeout(da9063);
+	if (timeout)
+		wdd->timeout = timeout;
+
+	/* Set timeout, maybe override it with DT value, scale it */
 	watchdog_init_timeout(wdd, 0, dev);
 	da9063_wdt_set_timeout(wdd, wdd->timeout);
 
-	/* Change the timeout to the default value if the watchdog is running */
-	if (da9063_wdt_is_running(da9063)) {
+	/* Update timeout if the watchdog is already running. */
+	if (timeout) {
 		da9063_wdt_update_timeout(da9063, wdd->timeout);
 		set_bit(WDOG_HW_RUNNING, &wdd->status);
 	}

drivers/watchdog/imx2_wdt.c

@@ -2,7 +2,7 @@
 /*
  * Watchdog driver for IMX2 and later processors
  *
- *  Copyright (C) 2010 Wolfram Sang, Pengutronix e.K. <w.sang@pengutronix.de>
+ *  Copyright (C) 2010 Wolfram Sang, Pengutronix e.K. <kernel@pengutronix.de>
  *  Copyright (C) 2014 Freescale Semiconductor, Inc.
  *
  * some parts adapted by similar drivers from Darius Augulis and Vladimir

drivers/watchdog/imx_sc_wdt.c

@@ -175,6 +175,11 @@ static int imx_sc_wdt_probe(struct platform_device *pdev)
 	wdog->timeout = DEFAULT_TIMEOUT;
 
 	watchdog_init_timeout(wdog, 0, dev);
+
+	ret = imx_sc_wdt_set_timeout(wdog, wdog->timeout);
+	if (ret)
+		return ret;
+
 	watchdog_stop_on_reboot(wdog);
 	watchdog_stop_on_unregister(wdog);
 

drivers/watchdog/m54xx_wdt.c

@@ -29,6 +29,7 @@
 #include <linux/bitops.h>
 #include <linux/ioport.h>
 #include <linux/uaccess.h>
+#include <linux/io.h>
 
 #include <asm/coldfire.h>
 #include <asm/m54xxsim.h>

drivers/watchdog/omap_wdt.c

@@ -273,6 +273,7 @@ static int omap_wdt_probe(struct platform_device *pdev)
 
 	ret = watchdog_register_device(&wdev->wdog);
 	if (ret) {
+		pm_runtime_put(wdev->dev);
 		pm_runtime_disable(wdev->dev);
 		return ret;
 	}

drivers/watchdog/riowd.c

@@ -141,7 +141,7 @@ static long riowd_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 
 	default:
 		return -EINVAL;
-	};
+	}
 
 	return 0;
 }