watchdog: add support for Sigma Designs SMP86xx/SMP87xx

This adds support for the Sigma Designs SMP86xx/SMP87xx family built-in watchdog. Signed-off-by: Mans Rullgard <mans@mansr.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

watchdog: add support for Sigma Designs SMP86xx/SMP87xx
This adds support for the Sigma Designs SMP86xx/SMP87xx family built-in watchdog. Signed-off-by: Mans Rullgard <mans@mansr.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Mans Rullgard · Wim Van Sebroeck
1 parent 5c6bb88a1b
Showing 3 changed files with 236 additions and 0 deletions Side-by-side Diff
drivers/watchdog/Kconfig
drivers/watchdog/Makefile
drivers/watchdog/tangox_wdt.c
@@ -142,6 +142,16 @@
 	  This driver can also be built as a module. If so the module
 	  will be called menf21bmc_wdt.
  
+config TANGOX_WATCHDOG
+	tristate "Sigma Designs SMP86xx/SMP87xx watchdog"
+	select WATCHDOG_CORE
+	depends on ARCH_TANGOX || COMPILE_TEST
+	help
+	  Support for the watchdog in Sigma Designs SMP86xx (tango3)
+	  and SMP87xx (tango4) family chips.
+
+	  This driver can be built as a module. The module name is tangox_wdt.
+
 config WM831X_WATCHDOG
 	tristate "WM831x watchdog"
 	depends on MFD_WM831X
@@ -190,6 +190,7 @@
 obj-$(CONFIG_DA9062_WATCHDOG) += da9062_wdt.o
 obj-$(CONFIG_DA9063_WATCHDOG) += da9063_wdt.o
 obj-$(CONFIG_GPIO_WATCHDOG)	+= gpio_wdt.o
+obj-$(CONFIG_TANGOX_WATCHDOG) += tangox_wdt.o
 obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
 obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
 obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o
+/*
+ *  Copyright (C) 2015 Mans Rullgard <mans@mansr.com>
+ *  SMP86xx/SMP87xx Watchdog driver
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under  the terms of the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the License, or (at your
+ *  option) any later version.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/notifier.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/watchdog.h>
+
+#define DEFAULT_TIMEOUT 30
+
+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) ")");
+
+static unsigned int timeout;
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout");
+
+/*
+ * Counter counts down from programmed value.  Reset asserts when
+ * the counter reaches 1.
+ */
+#define WD_COUNTER		0
+
+#define WD_CONFIG		4
+#define WD_CONFIG_XTAL_IN	BIT(0)
+#define WD_CONFIG_DISABLE	BIT(31)
+
+struct tangox_wdt_device {
+	struct watchdog_device wdt;
+	void __iomem *base;
+	unsigned long clk_rate;
+	struct clk *clk;
+	struct notifier_block restart;
+};
+
+static int tangox_wdt_set_timeout(struct watchdog_device *wdt,
+				  unsigned int new_timeout)
+{
+	wdt->timeout = new_timeout;
+
+	return 0;
+}
+
+static int tangox_wdt_start(struct watchdog_device *wdt)
+{
+	struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
+	u32 ticks;
+
+	ticks = 1 + wdt->timeout * dev->clk_rate;
+	writel(ticks, dev->base + WD_COUNTER);
+
+	return 0;
+}
+
+static int tangox_wdt_stop(struct watchdog_device *wdt)
+{
+	struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
+
+	writel(0, dev->base + WD_COUNTER);
+
+	return 0;
+}
+
+static unsigned int tangox_wdt_get_timeleft(struct watchdog_device *wdt)
+{
+	struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
+	u32 count;
+
+	count = readl(dev->base + WD_COUNTER);
+
+	if (!count)
+		return 0;
+
+	return (count - 1) / dev->clk_rate;
+}
+
+static const struct watchdog_info tangox_wdt_info = {
+	.options  = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+	.identity = "tangox watchdog",
+};
+
+static const struct watchdog_ops tangox_wdt_ops = {
+	.start		= tangox_wdt_start,
+	.stop		= tangox_wdt_stop,
+	.set_timeout	= tangox_wdt_set_timeout,
+	.get_timeleft	= tangox_wdt_get_timeleft,
+};
+
+static int tangox_wdt_restart(struct notifier_block *nb, unsigned long action,
+			      void *data)
+{
+	struct tangox_wdt_device *dev =
+		container_of(nb, struct tangox_wdt_device, restart);
+
+	writel(1, dev->base + WD_COUNTER);
+
+	return NOTIFY_DONE;
+}
+
+static int tangox_wdt_probe(struct platform_device *pdev)
+{
+	struct tangox_wdt_device *dev;
+	struct resource *res;
+	u32 config;
+	int err;
+
+	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	dev->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(dev->base))
+		return PTR_ERR(dev->base);
+
+	dev->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(dev->clk))
+		return PTR_ERR(dev->clk);
+
+	err = clk_prepare_enable(dev->clk);
+	if (err)
+		return err;
+
+	dev->clk_rate = clk_get_rate(dev->clk);
+
+	dev->wdt.parent = &pdev->dev;
+	dev->wdt.info = &tangox_wdt_info;
+	dev->wdt.ops = &tangox_wdt_ops;
+	dev->wdt.timeout = DEFAULT_TIMEOUT;
+	dev->wdt.min_timeout = 1;
+	dev->wdt.max_timeout = (U32_MAX - 1) / dev->clk_rate;
+
+	watchdog_init_timeout(&dev->wdt, timeout, &pdev->dev);
+	watchdog_set_nowayout(&dev->wdt, nowayout);
+	watchdog_set_drvdata(&dev->wdt, dev);
+
+	/*
+	 * Deactivate counter if disable bit is set to avoid
+	 * accidental reset.
+	 */
+	config = readl(dev->base + WD_CONFIG);
+	if (config & WD_CONFIG_DISABLE)
+		writel(0, dev->base + WD_COUNTER);
+
+	writel(WD_CONFIG_XTAL_IN, dev->base + WD_CONFIG);
+
+	/*
+	 * Mark as active and restart with configured timeout if
+	 * already running.
+	 */
+	if (readl(dev->base + WD_COUNTER)) {
+		set_bit(WDOG_ACTIVE, &dev->wdt.status);
+		tangox_wdt_start(&dev->wdt);
+	}
+
+	err = watchdog_register_device(&dev->wdt);
+	if (err) {
+		clk_disable_unprepare(dev->clk);
+		return err;
+	}
+
+	platform_set_drvdata(pdev, dev);
+
+	dev->restart.notifier_call = tangox_wdt_restart;
+	dev->restart.priority = 128;
+	err = register_restart_handler(&dev->restart);
+	if (err)
+		dev_warn(&pdev->dev, "failed to register restart handler\n");
+
+	dev_info(dev->wdt.dev, "SMP86xx/SMP87xx watchdog registered\n");
+
+	return 0;
+}
+
+static int tangox_wdt_remove(struct platform_device *pdev)
+{
+	struct tangox_wdt_device *dev = platform_get_drvdata(pdev);
+
+	tangox_wdt_stop(&dev->wdt);
+	clk_disable_unprepare(dev->clk);
+
+	unregister_restart_handler(&dev->restart);
+	watchdog_unregister_device(&dev->wdt);
+
+	return 0;
+}
+
+static const struct of_device_id tangox_wdt_dt_ids[] = {
+	{ .compatible = "sigma,smp8642-wdt" },
+	{ .compatible = "sigma,smp8759-wdt" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tangox_wdt_dt_ids);
+
+static struct platform_driver tangox_wdt_driver = {
+	.probe	= tangox_wdt_probe,
+	.remove	= tangox_wdt_remove,
+	.driver	= {
+		.name		= "tangox-wdt",
+		.of_match_table	= tangox_wdt_dt_ids,
+	},
+};
+
+module_platform_driver(tangox_wdt_driver);
+
+MODULE_AUTHOR("Mans Rullgard <mans@mansr.com>");
+MODULE_DESCRIPTION("SMP86xx/SMP87xx Watchdog driver");
+MODULE_LICENSE("GPL");
...	...	@@ -142,6 +142,16 @@
142	142	This driver can also be built as a module. If so the module
143	143	will be called menf21bmc_wdt.
144	144
	145	+config TANGOX_WATCHDOG
	146	+ tristate "Sigma Designs SMP86xx/SMP87xx watchdog"
	147	+ select WATCHDOG_CORE
	148	+ depends on ARCH_TANGOX \|\| COMPILE_TEST
	149	+ help
	150	+ Support for the watchdog in Sigma Designs SMP86xx (tango3)
	151	+ and SMP87xx (tango4) family chips.
	152	+
	153	+ This driver can be built as a module. The module name is tangox_wdt.
	154	+
145	155	config WM831X_WATCHDOG
146	156	tristate "WM831x watchdog"
147	157	depends on MFD_WM831X
...	...	@@ -190,6 +190,7 @@
190	190	obj-$(CONFIG_DA9062_WATCHDOG) += da9062_wdt.o
191	191	obj-$(CONFIG_DA9063_WATCHDOG) += da9063_wdt.o
192	192	obj-$(CONFIG_GPIO_WATCHDOG) += gpio_wdt.o
	193	+obj-$(CONFIG_TANGOX_WATCHDOG) += tangox_wdt.o
193	194	obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
194	195	obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
195	196	obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o
	1	+/*
	2	+ * Copyright (C) 2015 Mans Rullgard <mans@mansr.com>
	3	+ * SMP86xx/SMP87xx Watchdog driver
	4	+ *
	5	+ * This program is free software; you can redistribute it and/or modify it
	6	+ * under the terms of the GNU General Public License as published by the
	7	+ * Free Software Foundation; either version 2 of the License, or (at your
	8	+ * option) any later version.
	9	+ */
	10	+
	11	+#include <linux/bitops.h>
	12	+#include <linux/clk.h>
	13	+#include <linux/delay.h>
	14	+#include <linux/io.h>
	15	+#include <linux/kernel.h>
	16	+#include <linux/module.h>
	17	+#include <linux/moduleparam.h>
	18	+#include <linux/notifier.h>
	19	+#include <linux/platform_device.h>
	20	+#include <linux/reboot.h>
	21	+#include <linux/watchdog.h>
	22	+
	23	+#define DEFAULT_TIMEOUT 30
	24	+
	25	+static bool nowayout = WATCHDOG_NOWAYOUT;
	26	+module_param(nowayout, bool, 0);
	27	+MODULE_PARM_DESC(nowayout,
	28	+ "Watchdog cannot be stopped once started (default="
	29	+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	30	+
	31	+static unsigned int timeout;
	32	+module_param(timeout, int, 0);
	33	+MODULE_PARM_DESC(timeout, "Watchdog timeout");
	34	+
	35	+/*
	36	+ * Counter counts down from programmed value. Reset asserts when
	37	+ * the counter reaches 1.
	38	+ */
	39	+#define WD_COUNTER 0
	40	+
	41	+#define WD_CONFIG 4
	42	+#define WD_CONFIG_XTAL_IN BIT(0)
	43	+#define WD_CONFIG_DISABLE BIT(31)
	44	+
	45	+struct tangox_wdt_device {
	46	+ struct watchdog_device wdt;
	47	+ void __iomem *base;
	48	+ unsigned long clk_rate;
	49	+ struct clk *clk;
	50	+ struct notifier_block restart;
	51	+};
	52	+
	53	+static int tangox_wdt_set_timeout(struct watchdog_device *wdt,
	54	+ unsigned int new_timeout)
	55	+{
	56	+ wdt->timeout = new_timeout;
	57	+
	58	+ return 0;
	59	+}
	60	+
	61	+static int tangox_wdt_start(struct watchdog_device *wdt)
	62	+{
	63	+ struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
	64	+ u32 ticks;
	65	+
	66	+ ticks = 1 + wdt->timeout * dev->clk_rate;
	67	+ writel(ticks, dev->base + WD_COUNTER);
	68	+
	69	+ return 0;
	70	+}
	71	+
	72	+static int tangox_wdt_stop(struct watchdog_device *wdt)
	73	+{
	74	+ struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
	75	+
	76	+ writel(0, dev->base + WD_COUNTER);
	77	+
	78	+ return 0;
	79	+}
	80	+
	81	+static unsigned int tangox_wdt_get_timeleft(struct watchdog_device *wdt)
	82	+{
	83	+ struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
	84	+ u32 count;
	85	+
	86	+ count = readl(dev->base + WD_COUNTER);
	87	+
	88	+ if (!count)
	89	+ return 0;
	90	+
	91	+ return (count - 1) / dev->clk_rate;
	92	+}
	93	+
	94	+static const struct watchdog_info tangox_wdt_info = {
	95	+ .options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
	96	+ .identity = "tangox watchdog",
	97	+};
	98	+
	99	+static const struct watchdog_ops tangox_wdt_ops = {
	100	+ .start = tangox_wdt_start,
	101	+ .stop = tangox_wdt_stop,
	102	+ .set_timeout = tangox_wdt_set_timeout,
	103	+ .get_timeleft = tangox_wdt_get_timeleft,
	104	+};
	105	+
	106	+static int tangox_wdt_restart(struct notifier_block *nb, unsigned long action,
	107	+ void *data)
	108	+{
	109	+ struct tangox_wdt_device *dev =
	110	+ container_of(nb, struct tangox_wdt_device, restart);
	111	+
	112	+ writel(1, dev->base + WD_COUNTER);
	113	+
	114	+ return NOTIFY_DONE;
	115	+}
	116	+
	117	+static int tangox_wdt_probe(struct platform_device *pdev)
	118	+{
	119	+ struct tangox_wdt_device *dev;
	120	+ struct resource *res;
	121	+ u32 config;
	122	+ int err;
	123	+
	124	+ dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
	125	+ if (!dev)
	126	+ return -ENOMEM;
	127	+
	128	+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	129	+ dev->base = devm_ioremap_resource(&pdev->dev, res);
	130	+ if (IS_ERR(dev->base))
	131	+ return PTR_ERR(dev->base);
	132	+
	133	+ dev->clk = devm_clk_get(&pdev->dev, NULL);
	134	+ if (IS_ERR(dev->clk))
	135	+ return PTR_ERR(dev->clk);
	136	+
	137	+ err = clk_prepare_enable(dev->clk);
	138	+ if (err)
	139	+ return err;
	140	+
	141	+ dev->clk_rate = clk_get_rate(dev->clk);
	142	+
	143	+ dev->wdt.parent = &pdev->dev;
	144	+ dev->wdt.info = &tangox_wdt_info;
	145	+ dev->wdt.ops = &tangox_wdt_ops;
	146	+ dev->wdt.timeout = DEFAULT_TIMEOUT;
	147	+ dev->wdt.min_timeout = 1;
	148	+ dev->wdt.max_timeout = (U32_MAX - 1) / dev->clk_rate;
	149	+
	150	+ watchdog_init_timeout(&dev->wdt, timeout, &pdev->dev);
	151	+ watchdog_set_nowayout(&dev->wdt, nowayout);
	152	+ watchdog_set_drvdata(&dev->wdt, dev);
	153	+
	154	+ /*
	155	+ * Deactivate counter if disable bit is set to avoid
	156	+ * accidental reset.
	157	+ */
	158	+ config = readl(dev->base + WD_CONFIG);
	159	+ if (config & WD_CONFIG_DISABLE)
	160	+ writel(0, dev->base + WD_COUNTER);
	161	+
	162	+ writel(WD_CONFIG_XTAL_IN, dev->base + WD_CONFIG);
	163	+
	164	+ /*
	165	+ * Mark as active and restart with configured timeout if
	166	+ * already running.
	167	+ */
	168	+ if (readl(dev->base + WD_COUNTER)) {
	169	+ set_bit(WDOG_ACTIVE, &dev->wdt.status);
	170	+ tangox_wdt_start(&dev->wdt);
	171	+ }
	172	+
	173	+ err = watchdog_register_device(&dev->wdt);
	174	+ if (err) {
	175	+ clk_disable_unprepare(dev->clk);
	176	+ return err;
	177	+ }
	178	+
	179	+ platform_set_drvdata(pdev, dev);
	180	+
	181	+ dev->restart.notifier_call = tangox_wdt_restart;
	182	+ dev->restart.priority = 128;
	183	+ err = register_restart_handler(&dev->restart);
	184	+ if (err)
	185	+ dev_warn(&pdev->dev, "failed to register restart handler\n");
	186	+
	187	+ dev_info(dev->wdt.dev, "SMP86xx/SMP87xx watchdog registered\n");
	188	+
	189	+ return 0;
	190	+}
	191	+
	192	+static int tangox_wdt_remove(struct platform_device *pdev)
	193	+{
	194	+ struct tangox_wdt_device *dev = platform_get_drvdata(pdev);
	195	+
	196	+ tangox_wdt_stop(&dev->wdt);
	197	+ clk_disable_unprepare(dev->clk);
	198	+
	199	+ unregister_restart_handler(&dev->restart);
	200	+ watchdog_unregister_device(&dev->wdt);
	201	+
	202	+ return 0;
	203	+}
	204	+
	205	+static const struct of_device_id tangox_wdt_dt_ids[] = {
	206	+ { .compatible = "sigma,smp8642-wdt" },
	207	+ { .compatible = "sigma,smp8759-wdt" },
	208	+ { }
	209	+};
	210	+MODULE_DEVICE_TABLE(of, tangox_wdt_dt_ids);
	211	+
	212	+static struct platform_driver tangox_wdt_driver = {
	213	+ .probe = tangox_wdt_probe,
	214	+ .remove = tangox_wdt_remove,
	215	+ .driver = {
	216	+ .name = "tangox-wdt",
	217	+ .of_match_table = tangox_wdt_dt_ids,
	218	+ },
	219	+};
	220	+
	221	+module_platform_driver(tangox_wdt_driver);
	222	+
	223	+MODULE_AUTHOR("Mans Rullgard <mans@mansr.com>");
	224	+MODULE_DESCRIPTION("SMP86xx/SMP87xx Watchdog driver");
	225	+MODULE_LICENSE("GPL");