Merge tag 'topic-sbsa-watchdog-erp-20160426.0' into leg-kernel

7 files changed, 482 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/watchdog/sbsa-gwdt.txt b/Documentation/devicetree/bindings/watchdog/sbsa-gwdt.txt
new file mode 100644
index 000000000000..6f2d5f91964d
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/sbsa-gwdt.txt
@@ -0,0 +1,31 @@
+* SBSA (Server Base System Architecture) Generic Watchdog
+
+The SBSA Generic Watchdog Timer is used to force a reset of the system
+after two stages of timeout have elapsed.  A detailed definition of the
+watchdog timer can be found in the ARM document: ARM-DEN-0029 - Server
+Base System Architecture (SBSA)
+
+Required properties:
+- compatible: Should at least contain "arm,sbsa-gwdt".
+
+- reg: Each entry specifies the base physical address of a register frame
+  and the length of that frame; currently, two frames must be defined,
+  in this order:
+  1: Watchdog control frame;
+  2: Refresh frame.
+
+- interrupts: Should contain the Watchdog Signal 0 (WS0) SPI (Shared
+  Peripheral Interrupt) number of SBSA Generic Watchdog.
+
+Optional properties
+- timeout-sec: Watchdog timeout values (in seconds).
+
+Example for FVP Foundation Model v8:
+
+watchdog@2a440000 {
+	compatible = "arm,sbsa-gwdt";
+	reg = <0x0 0x2a440000 0 0x1000>,
+	      <0x0 0x2a450000 0 0x1000>;
+	interrupts = <0 27 4>;
+	timeout-sec = <30>;
+};
diff --git a/Documentation/watchdog/watchdog-parameters.txt b/Documentation/watchdog/watchdog-parameters.txt
index 9f9ec9f76039..ce7ae4ee94e0 100644
--- a/Documentation/watchdog/watchdog-parameters.txt
+++ b/Documentation/watchdog/watchdog-parameters.txt
@@ -284,6 +284,13 @@ sbc_fitpc2_wdt:
 margin: Watchdog margin in seconds (default 60s)
 nowayout: Watchdog cannot be stopped once started
 -------------------------------------------------
+sbsa_gwdt:
+timeout: Watchdog timeout in seconds. (default 10s)
+action: Watchdog action at the first stage timeout,
+	set to 0 to ignore, 1 to panic. (default=0)
+nowayout: Watchdog cannot be stopped once started
+	(default=kernel config parameter)
+-------------------------------------------------
 sc1200wdt:
 isapnp: When set to 0 driver ISA PnP support will be disabled (default=1)
 io: io port
diff --git a/arch/arm64/boot/dts/amd/amd-seattle-soc.dtsi b/arch/arm64/boot/dts/amd/amd-seattle-soc.dtsi
index 2874d92881fd..0a8ca1de467a 100644
--- a/arch/arm64/boot/dts/amd/amd-seattle-soc.dtsi
+++ b/arch/arm64/boot/dts/amd/amd-seattle-soc.dtsi
@@ -84,6 +84,14 @@
 			clock-names = "uartclk", "apb_pclk";
 		};
 
+		watchdog0: watchdog@e0bb0000 {
+			compatible = "arm,sbsa-gwdt";
+			reg = <0x0 0xe0bc0000 0 0x1000>,
+				<0x0 0xe0bb0000 0 0x1000>;
+			interrupts = <0 337 4>;
+			timeout-sec = <15>;
+		};
+
 		spi0: ssp@e1020000 {
 			status = "disabled";
 			compatible = "arm,pl022", "arm,primecell";
diff --git a/arch/arm64/boot/dts/arm/foundation-v8.dts b/arch/arm64/boot/dts/arm/foundation-v8.dts
index 4eac8dcea423..66cb9aaa9135 100644
--- a/arch/arm64/boot/dts/arm/foundation-v8.dts
+++ b/arch/arm64/boot/dts/arm/foundation-v8.dts
@@ -237,4 +237,11 @@
 			};
 		};
 	};
+	watchdog@2a440000 {
+		compatible = "arm,sbsa-gwdt";
+		reg = <0x0 0x2a440000 0 0x1000>,
+			<0x0 0x2a450000 0 0x1000>;
+		interrupts = <0 27 4>;
+		timeout-sec = <30>;
+	};
 };
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 1c427beffadd..96e944e56ceb 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -173,6 +173,26 @@ config ARM_SP805_WATCHDOG
 	  ARM Primecell SP805 Watchdog timer. This will reboot your system when
 	  the timeout is reached.
 
+config ARM_SBSA_WATCHDOG
+	tristate "ARM SBSA Generic Watchdog"
+	depends on ARM64
+	depends on ARM_ARCH_TIMER
+	select WATCHDOG_CORE
+	help
+	  ARM SBSA Generic Watchdog has two stage timeouts:
+	  the first signal (WS0) is for alerting the system by interrupt,
+	  the second one (WS1) is a real hardware reset.
+	  More details: ARM DEN0029B - Server Base System Architecture (SBSA)
+
+	  This driver can operate ARM SBSA Generic Watchdog as a single stage
+	  or a two stages watchdog, it depends on the module parameter "action".
+
+	  Note: the maximum timeout in the two stages mode is half of that in
+	  the single stage mode.
+
+	  To compile this driver as module, choose M here: The module
+	  will be called sbsa_gwdt.
+
 config AT91RM9200_WATCHDOG
 	tristate "AT91RM9200 watchdog"
 	depends on SOC_AT91RM9200 && MFD_SYSCON
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 53d4827ddfe1..66b2062114dc 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_USBPCWATCHDOG) += pcwd_usb.o
 
 # ARM Architecture
 obj-$(CONFIG_ARM_SP805_WATCHDOG) += sp805_wdt.o
+obj-$(CONFIG_ARM_SBSA_WATCHDOG) += sbsa_gwdt.o
 obj-$(CONFIG_AT91RM9200_WATCHDOG) += at91rm9200_wdt.o
 obj-$(CONFIG_AT91SAM9X_WATCHDOG) += at91sam9_wdt.o
 obj-$(CONFIG_CADENCE_WATCHDOG) += cadence_wdt.o
diff --git a/drivers/watchdog/sbsa_gwdt.c b/drivers/watchdog/sbsa_gwdt.c
new file mode 100644
index 000000000000..ad383f6f15fc
--- /dev/null
+++ b/drivers/watchdog/sbsa_gwdt.c
@@ -0,0 +1,408 @@
+/*
+ * SBSA(Server Base System Architecture) Generic Watchdog driver
+ *
+ * Copyright (c) 2015, Linaro Ltd.
+ * Author: Fu Wei <fu.wei@linaro.org>
+ *         Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
+ *         Al Stone <al.stone@linaro.org>
+ *         Timur Tabi <timur@codeaurora.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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.
+ *
+ * ARM SBSA Generic Watchdog has two stage timeouts:
+ * the first signal (WS0) is for alerting the system by interrupt,
+ * the second one (WS1) is a real hardware reset.
+ * More details about the hardware specification of this device:
+ * ARM DEN0029B - Server Base System Architecture (SBSA)
+ *
+ * This driver can operate ARM SBSA Generic Watchdog as a single stage watchdog
+ * or a two stages watchdog, it's set up by the module parameter "action".
+ * In the single stage mode, when the timeout is reached, your system
+ * will be reset by WS1. The first signal (WS0) is ignored.
+ * In the two stages mode, when the timeout is reached, the first signal (WS0)
+ * will trigger panic. If the system is getting into trouble and cannot be reset
+ * by panic or restart properly by the kdump kernel(if supported), then the
+ * second stage (as long as the first stage) will be reached, system will be
+ * reset by WS1. This function can help administrator to backup the system
+ * context info by panic console output or kdump.
+ *
+ * SBSA GWDT:
+ * if action is 1 (the two stages mode):
+ * |--------WOR-------WS0--------WOR-------WS1
+ * |----timeout-----(panic)----timeout-----reset
+ *
+ * if action is 0 (the single stage mode):
+ * |------WOR-----WS0(ignored)-----WOR------WS1
+ * |--------------timeout-------------------reset
+ *
+ * Note: Since this watchdog timer has two stages, and each stage is determined
+ * by WOR, in the single stage mode, the timeout is (WOR * 2); in the two
+ * stages mode, the timeout is WOR. The maximum timeout in the two stages mode
+ * is half of that in the single stage mode.
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/uaccess.h>
+#include <linux/watchdog.h>
+#include <asm/arch_timer.h>
+
+#define DRV_NAME		"sbsa-gwdt"
+#define WATCHDOG_NAME		"SBSA Generic Watchdog"
+
+/* SBSA Generic Watchdog register definitions */
+/* refresh frame */
+#define SBSA_GWDT_WRR		0x000
+
+/* control frame */
+#define SBSA_GWDT_WCS		0x000
+#define SBSA_GWDT_WOR		0x008
+#define SBSA_GWDT_WCV		0x010
+
+/* refresh/control frame */
+#define SBSA_GWDT_W_IIDR	0xfcc
+#define SBSA_GWDT_IDR		0xfd0
+
+/* Watchdog Control and Status Register */
+#define SBSA_GWDT_WCS_EN	BIT(0)
+#define SBSA_GWDT_WCS_WS0	BIT(1)
+#define SBSA_GWDT_WCS_WS1	BIT(2)
+
+/**
+ * struct sbsa_gwdt - Internal representation of the SBSA GWDT
+ * @wdd:		kernel watchdog_device structure
+ * @clk:		store the System Counter clock frequency, in Hz.
+ * @refresh_base:	Virtual address of the watchdog refresh frame
+ * @control_base:	Virtual address of the watchdog control frame
+ */
+struct sbsa_gwdt {
+	struct watchdog_device	wdd;
+	u32			clk;
+	void __iomem		*refresh_base;
+	void __iomem		*control_base;
+};
+
+#define DEFAULT_TIMEOUT		10 /* seconds */
+
+static unsigned int timeout;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout,
+		 "Watchdog timeout in seconds. (>=0, default="
+		 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
+
+/*
+ * action refers to action taken when watchdog gets WS0
+ * 0 = skip
+ * 1 = panic
+ * defaults to skip (0)
+ */
+static int action;
+module_param(action, int, 0);
+MODULE_PARM_DESC(action, "after watchdog gets WS0 interrupt, do: "
+		 "0 = skip(*)  1 = panic");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, S_IRUGO);
+MODULE_PARM_DESC(nowayout,
+		 "Watchdog cannot be stopped once started (default="
+		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+/*
+ * watchdog operation functions
+ */
+static int sbsa_gwdt_set_timeout(struct watchdog_device *wdd,
+				 unsigned int timeout)
+{
+	struct sbsa_gwdt *gwdt = watchdog_get_drvdata(wdd);
+
+	wdd->timeout = timeout;
+
+	if (action)
+		writel(gwdt->clk * timeout,
+		       gwdt->control_base + SBSA_GWDT_WOR);
+	else
+		/*
+		 * In the single stage mode, The first signal (WS0) is ignored,
+		 * the timeout is (WOR * 2), so the WOR should be configured
+		 * to half value of timeout.
+		 */
+		writel(gwdt->clk / 2 * timeout,
+		       gwdt->control_base + SBSA_GWDT_WOR);
+
+	return 0;
+}
+
+static unsigned int sbsa_gwdt_get_timeleft(struct watchdog_device *wdd)
+{
+	struct sbsa_gwdt *gwdt = watchdog_get_drvdata(wdd);
+	u64 timeleft = 0;
+
+	/*
+	 * In the single stage mode, if WS0 is deasserted
+	 * (watchdog is in the first stage),
+	 * timeleft = WOR + (WCV - system counter)
+	 */
+	if (!action &&
+	    !(readl(gwdt->control_base + SBSA_GWDT_WCS) & SBSA_GWDT_WCS_WS0))
+		timeleft += readl(gwdt->control_base + SBSA_GWDT_WOR);
+
+	timeleft += readq(gwdt->control_base + SBSA_GWDT_WCV) -
+		    arch_counter_get_cntvct();
+
+	do_div(timeleft, gwdt->clk);
+
+	return timeleft;
+}
+
+static int sbsa_gwdt_keepalive(struct watchdog_device *wdd)
+{
+	struct sbsa_gwdt *gwdt = watchdog_get_drvdata(wdd);
+
+	/*
+	 * Writing WRR for an explicit watchdog refresh.
+	 * You can write anyting (like 0).
+	 */
+	writel(0, gwdt->refresh_base + SBSA_GWDT_WRR);
+
+	return 0;
+}
+
+static unsigned int sbsa_gwdt_status(struct watchdog_device *wdd)
+{
+	struct sbsa_gwdt *gwdt = watchdog_get_drvdata(wdd);
+	u32 status = readl(gwdt->control_base + SBSA_GWDT_WCS);
+
+	/* is the watchdog timer running? */
+	return (status & SBSA_GWDT_WCS_EN) << WDOG_ACTIVE;
+}
+
+static int sbsa_gwdt_start(struct watchdog_device *wdd)
+{
+	struct sbsa_gwdt *gwdt = watchdog_get_drvdata(wdd);
+
+	/* writing WCS will cause an explicit watchdog refresh */
+	writel(SBSA_GWDT_WCS_EN, gwdt->control_base + SBSA_GWDT_WCS);
+
+	return 0;
+}
+
+static int sbsa_gwdt_stop(struct watchdog_device *wdd)
+{
+	struct sbsa_gwdt *gwdt = watchdog_get_drvdata(wdd);
+
+	/* Simply write 0 to WCS to clean WCS_EN bit */
+	writel(0, gwdt->control_base + SBSA_GWDT_WCS);
+
+	return 0;
+}
+
+static irqreturn_t sbsa_gwdt_interrupt(int irq, void *dev_id)
+{
+	panic(WATCHDOG_NAME " timeout");
+
+	return IRQ_HANDLED;
+}
+
+static struct watchdog_info sbsa_gwdt_info = {
+	.identity	= WATCHDOG_NAME,
+	.options	= WDIOF_SETTIMEOUT |
+			  WDIOF_KEEPALIVEPING |
+			  WDIOF_MAGICCLOSE |
+			  WDIOF_CARDRESET,
+};
+
+static struct watchdog_ops sbsa_gwdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= sbsa_gwdt_start,
+	.stop		= sbsa_gwdt_stop,
+	.status		= sbsa_gwdt_status,
+	.ping		= sbsa_gwdt_keepalive,
+	.set_timeout	= sbsa_gwdt_set_timeout,
+	.get_timeleft	= sbsa_gwdt_get_timeleft,
+};
+
+static int sbsa_gwdt_probe(struct platform_device *pdev)
+{
+	void __iomem *rf_base, *cf_base;
+	struct device *dev = &pdev->dev;
+	struct watchdog_device *wdd;
+	struct sbsa_gwdt *gwdt;
+	struct resource *res;
+	int ret, irq;
+	u32 status;
+
+	gwdt = devm_kzalloc(dev, sizeof(*gwdt), GFP_KERNEL);
+	if (!gwdt)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, gwdt);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	cf_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(cf_base))
+		return PTR_ERR(cf_base);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	rf_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(rf_base))
+		return PTR_ERR(rf_base);
+
+	/*
+	 * Get the frequency of system counter from the cp15 interface of ARM
+	 * Generic timer. We don't need to check it, because if it returns "0",
+	 * system would panic in very early stage.
+	 */
+	gwdt->clk = arch_timer_get_cntfrq();
+	gwdt->refresh_base = rf_base;
+	gwdt->control_base = cf_base;
+
+	wdd = &gwdt->wdd;
+	wdd->parent = dev;
+	wdd->info = &sbsa_gwdt_info;
+	wdd->ops = &sbsa_gwdt_ops;
+	wdd->min_timeout = 1;
+	wdd->max_timeout = U32_MAX / gwdt->clk;
+	wdd->timeout = DEFAULT_TIMEOUT;
+	watchdog_set_drvdata(wdd, gwdt);
+	watchdog_set_nowayout(wdd, nowayout);
+
+	status = readl(cf_base + SBSA_GWDT_WCS);
+	if (status & SBSA_GWDT_WCS_WS1) {
+		dev_warn(dev, "System reset by WDT.\n");
+		wdd->bootstatus |= WDIOF_CARDRESET;
+	}
+
+	if (action) {
+		irq = platform_get_irq(pdev, 0);
+		if (irq < 0) {
+			action = 0;
+			dev_warn(dev, "unable to get ws0 interrupt.\n");
+		} else {
+			/*
+			 * In case there is a pending ws0 interrupt, just ping
+			 * the watchdog before registering the interrupt routine
+			 */
+			writel(0, rf_base + SBSA_GWDT_WRR);
+			if (devm_request_irq(dev, irq, sbsa_gwdt_interrupt, 0,
+					     pdev->name, gwdt)) {
+				action = 0;
+				dev_warn(dev, "unable to request IRQ %d.\n",
+					 irq);
+			}
+		}
+		if (!action)
+			dev_warn(dev, "falling back to single stage mode.\n");
+	}
+	/*
+	 * In the single stage mode, The first signal (WS0) is ignored,
+	 * the timeout is (WOR * 2), so the maximum timeout should be doubled.
+	 */
+	if (!action)
+		wdd->max_timeout *= 2;
+
+	watchdog_init_timeout(wdd, timeout, dev);
+	/*
+	 * Update timeout to WOR.
+	 * Because of the explicit watchdog refresh mechanism,
+	 * it's also a ping, if watchdog is enabled.
+	 */
+	sbsa_gwdt_set_timeout(wdd, wdd->timeout);
+
+	ret = watchdog_register_device(wdd);
+	if (ret)
+		return ret;
+
+	dev_info(dev, "Initialized with %ds timeout @ %u Hz, action=%d.%s\n",
+		 wdd->timeout, gwdt->clk, action,
+		 status & SBSA_GWDT_WCS_EN ? " [enabled]" : "");
+
+	return 0;
+}
+
+static void sbsa_gwdt_shutdown(struct platform_device *pdev)
+{
+	struct sbsa_gwdt *gwdt = platform_get_drvdata(pdev);
+
+	sbsa_gwdt_stop(&gwdt->wdd);
+}
+
+static int sbsa_gwdt_remove(struct platform_device *pdev)
+{
+	struct sbsa_gwdt *gwdt = platform_get_drvdata(pdev);
+
+	watchdog_unregister_device(&gwdt->wdd);
+
+	return 0;
+}
+
+/* Disable watchdog if it is active during suspend */
+static int __maybe_unused sbsa_gwdt_suspend(struct device *dev)
+{
+	struct sbsa_gwdt *gwdt = dev_get_drvdata(dev);
+
+	if (watchdog_active(&gwdt->wdd))
+		sbsa_gwdt_stop(&gwdt->wdd);
+
+	return 0;
+}
+
+/* Enable watchdog if necessary */
+static int __maybe_unused sbsa_gwdt_resume(struct device *dev)
+{
+	struct sbsa_gwdt *gwdt = dev_get_drvdata(dev);
+
+	if (watchdog_active(&gwdt->wdd))
+		sbsa_gwdt_start(&gwdt->wdd);
+
+	return 0;
+}
+
+static const struct dev_pm_ops sbsa_gwdt_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(sbsa_gwdt_suspend, sbsa_gwdt_resume)
+};
+
+static const struct of_device_id sbsa_gwdt_of_match[] = {
+	{ .compatible = "arm,sbsa-gwdt", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, sbsa_gwdt_of_match);
+
+static const struct platform_device_id sbsa_gwdt_pdev_match[] = {
+	{ .name = DRV_NAME, },
+	{},
+};
+MODULE_DEVICE_TABLE(platform, sbsa_gwdt_pdev_match);
+
+static struct platform_driver sbsa_gwdt_driver = {
+	.driver = {
+		.name = DRV_NAME,
+		.pm = &sbsa_gwdt_pm_ops,
+		.of_match_table = sbsa_gwdt_of_match,
+	},
+	.probe = sbsa_gwdt_probe,
+	.remove = sbsa_gwdt_remove,
+	.shutdown = sbsa_gwdt_shutdown,
+	.id_table = sbsa_gwdt_pdev_match,
+};
+
+module_platform_driver(sbsa_gwdt_driver);
+
+MODULE_DESCRIPTION("SBSA Generic Watchdog Driver");
+MODULE_AUTHOR("Fu Wei <fu.wei@linaro.org>");
+MODULE_AUTHOR("Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>");
+MODULE_AUTHOR("Al Stone <al.stone@linaro.org>");
+MODULE_AUTHOR("Timur Tabi <timur@codeaurora.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRV_NAME);