watchdog: menf21bmc_wdt: Introduce MEN 14F021P00 BMC Watchdog driver

Added driver to support the 14F021P00 BMC Watchdog. The BMC is a Board Management Controller including watchdog functionality. Signed-off-by: Andreas Werner <andreas.werner@men.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Lee Jones <lee.jones@linaro.org>

watchdog: menf21bmc_wdt: Introduce MEN 14F021P00 BMC Watchdog driver
Added driver to support the 14F021P00 BMC Watchdog. The BMC is a Board Management Controller including watchdog functionality. Signed-off-by: Andreas Werner <andreas.werner@men.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Lee Jones <lee.jones@linaro.org>
Andreas Werner · Lee Jones
1 parent dfbdcd7cef
Showing 3 changed files with 214 additions and 0 deletions Side-by-side Diff
drivers/watchdog/Kconfig
drivers/watchdog/Makefile
drivers/watchdog/menf21bmc_wdt.c
@@ -95,6 +95,16 @@
 	  If you say yes here you get support for watchdog device
 	  controlled through GPIO-line.
  
+config MENF21BMC_WATCHDOG
+	tristate "MEN 14F021P00 BMC Watchdog"
+	depends on MFD_MENF21BMC
+	select WATCHDOG_CORE
+	help
+	  Say Y here to include support for the MEN 14F021P00 BMC Watchdog.
+
+	  This driver can also be built as a module. If so the module
+	  will be called menf21bmc_wdt.
+
 config WM831X_WATCHDOG
 	tristate "WM831x watchdog"
 	depends on MFD_WM831X
@@ -178,4 +178,5 @@
 obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
 obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o
 obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o
+obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o
+/*
+ *  MEN 14F021P00 Board Management Controller (BMC) Watchdog Driver.
+ *
+ *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
+ *
+ *  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/kernel.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+
+#define DEVNAME "menf21bmc_wdt"
+
+#define BMC_CMD_WD_ON		0x11
+#define BMC_CMD_WD_OFF		0x12
+#define BMC_CMD_WD_TRIG		0x13
+#define BMC_CMD_WD_TIME		0x14
+#define BMC_CMD_WD_STATE	0x17
+#define BMC_WD_OFF_VAL		0x69
+#define BMC_CMD_RST_RSN		0x92
+
+#define BMC_WD_TIMEOUT_MIN	1	/* in sec */
+#define BMC_WD_TIMEOUT_MAX	6553	/* in sec */
+
+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 menf21bmc_wdt {
+	struct watchdog_device wdt;
+	struct i2c_client *i2c_client;
+};
+
+static int menf21bmc_wdt_set_bootstatus(struct menf21bmc_wdt *data)
+{
+	int rst_rsn;
+
+	rst_rsn = i2c_smbus_read_byte_data(data->i2c_client, BMC_CMD_RST_RSN);
+	if (rst_rsn < 0)
+		return rst_rsn;
+
+	if (rst_rsn == 0x02)
+		data->wdt.bootstatus |= WDIOF_CARDRESET;
+	else if (rst_rsn == 0x05)
+		data->wdt.bootstatus |= WDIOF_EXTERN1;
+	else if (rst_rsn == 0x06)
+		data->wdt.bootstatus |= WDIOF_EXTERN2;
+	else if (rst_rsn == 0x0A)
+		data->wdt.bootstatus |= WDIOF_POWERUNDER;
+
+	return 0;
+}
+
+static int menf21bmc_wdt_start(struct watchdog_device *wdt)
+{
+	struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+	return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_ON);
+}
+
+static int menf21bmc_wdt_stop(struct watchdog_device *wdt)
+{
+	struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+	return i2c_smbus_write_byte_data(drv_data->i2c_client,
+					 BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
+}
+
+static int
+menf21bmc_wdt_settimeout(struct watchdog_device *wdt, unsigned int timeout)
+{
+	int ret;
+	struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+	/*
+	 *  BMC Watchdog does have a resolution of 100ms.
+	 *  Watchdog API defines the timeout in seconds, so we have to
+	 *  multiply the value.
+	 */
+	ret = i2c_smbus_write_word_data(drv_data->i2c_client,
+					BMC_CMD_WD_TIME, timeout * 10);
+	if (ret < 0)
+		return ret;
+
+	wdt->timeout = timeout;
+
+	return 0;
+}
+
+static int menf21bmc_wdt_ping(struct watchdog_device *wdt)
+{
+	struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+	return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_TRIG);
+}
+
+static const struct watchdog_info menf21bmc_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+	.identity = DEVNAME,
+};
+
+static const struct watchdog_ops menf21bmc_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= menf21bmc_wdt_start,
+	.stop		= menf21bmc_wdt_stop,
+	.ping		= menf21bmc_wdt_ping,
+	.set_timeout	= menf21bmc_wdt_settimeout,
+};
+
+static int menf21bmc_wdt_probe(struct platform_device *pdev)
+{
+	int ret, bmc_timeout;
+	struct menf21bmc_wdt *drv_data;
+	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
+
+	drv_data = devm_kzalloc(&pdev->dev,
+				sizeof(struct menf21bmc_wdt), GFP_KERNEL);
+	if (!drv_data)
+		return -ENOMEM;
+
+	drv_data->wdt.ops = &menf21bmc_wdt_ops;
+	drv_data->wdt.info = &menf21bmc_wdt_info;
+	drv_data->wdt.min_timeout = BMC_WD_TIMEOUT_MIN;
+	drv_data->wdt.max_timeout = BMC_WD_TIMEOUT_MAX;
+	drv_data->i2c_client = i2c_client;
+
+	/*
+	 * Get the current wdt timeout value from the BMC because
+	 * the BMC will save the value set before if the system restarts.
+	 */
+	bmc_timeout = i2c_smbus_read_word_data(drv_data->i2c_client,
+					       BMC_CMD_WD_TIME);
+	if (bmc_timeout < 0) {
+		dev_err(&pdev->dev, "failed to get current WDT timeout\n");
+		return bmc_timeout;
+	}
+
+	watchdog_init_timeout(&drv_data->wdt, bmc_timeout / 10, &pdev->dev);
+	watchdog_set_nowayout(&drv_data->wdt, nowayout);
+	watchdog_set_drvdata(&drv_data->wdt, drv_data);
+	platform_set_drvdata(pdev, drv_data);
+
+	ret = menf21bmc_wdt_set_bootstatus(drv_data);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to set Watchdog bootstatus\n");
+		return ret;
+	}
+
+	ret = watchdog_register_device(&drv_data->wdt);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register Watchdog device\n");
+		return ret;
+	}
+
+	dev_info(&pdev->dev, "MEN 14F021P00 BMC Watchdog device enabled\n");
+
+	return 0;
+}
+
+static int menf21bmc_wdt_remove(struct platform_device *pdev)
+{
+	struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
+
+	dev_warn(&pdev->dev,
+		 "Unregister MEN 14F021P00 BMC Watchdog device, board may reset\n");
+
+	watchdog_unregister_device(&drv_data->wdt);
+
+	return 0;
+}
+
+static void menf21bmc_wdt_shutdown(struct platform_device *pdev)
+{
+	struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
+
+	i2c_smbus_write_word_data(drv_data->i2c_client,
+				  BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
+}
+
+static struct  platform_driver menf21bmc_wdt = {
+	.driver		= {
+		.owner = THIS_MODULE,
+		.name	= DEVNAME,
+	},
+	.probe		= menf21bmc_wdt_probe,
+	.remove		= menf21bmc_wdt_remove,
+	.shutdown	= menf21bmc_wdt_shutdown,
+};
+
+module_platform_driver(menf21bmc_wdt);
+
+MODULE_DESCRIPTION("MEN 14F021P00 BMC Watchdog driver");
+MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:menf21bmc_wdt");
...	...	@@ -95,6 +95,16 @@
95	95	If you say yes here you get support for watchdog device
96	96	controlled through GPIO-line.
97	97
	98	+config MENF21BMC_WATCHDOG
	99	+ tristate "MEN 14F021P00 BMC Watchdog"
	100	+ depends on MFD_MENF21BMC
	101	+ select WATCHDOG_CORE
	102	+ help
	103	+ Say Y here to include support for the MEN 14F021P00 BMC Watchdog.
	104	+
	105	+ This driver can also be built as a module. If so the module
	106	+ will be called menf21bmc_wdt.
	107	+
98	108	config WM831X_WATCHDOG
99	109	tristate "WM831x watchdog"
100	110	depends on MFD_WM831X
...	...	@@ -178,4 +178,5 @@
178	178	obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
179	179	obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o
180	180	obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o
	181	+obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o
	1	+/*
	2	+ * MEN 14F021P00 Board Management Controller (BMC) Watchdog Driver.
	3	+ *
	4	+ * Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
	5	+ *
	6	+ * This program is free software; you can redistribute it and/or modify it
	7	+ * under the terms of the GNU General Public License as published by the
	8	+ * Free Software Foundation; either version 2 of the License, or (at your
	9	+ * option) any later version.
	10	+ */
	11	+
	12	+#include <linux/kernel.h>
	13	+#include <linux/device.h>
	14	+#include <linux/module.h>
	15	+#include <linux/watchdog.h>
	16	+#include <linux/platform_device.h>
	17	+#include <linux/i2c.h>
	18	+
	19	+#define DEVNAME "menf21bmc_wdt"
	20	+
	21	+#define BMC_CMD_WD_ON 0x11
	22	+#define BMC_CMD_WD_OFF 0x12
	23	+#define BMC_CMD_WD_TRIG 0x13
	24	+#define BMC_CMD_WD_TIME 0x14
	25	+#define BMC_CMD_WD_STATE 0x17
	26	+#define BMC_WD_OFF_VAL 0x69
	27	+#define BMC_CMD_RST_RSN 0x92
	28	+
	29	+#define BMC_WD_TIMEOUT_MIN 1 /* in sec */
	30	+#define BMC_WD_TIMEOUT_MAX 6553 /* in sec */
	31	+
	32	+static bool nowayout = WATCHDOG_NOWAYOUT;
	33	+module_param(nowayout, bool, 0);
	34	+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
	35	+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	36	+
	37	+struct menf21bmc_wdt {
	38	+ struct watchdog_device wdt;
	39	+ struct i2c_client *i2c_client;
	40	+};
	41	+
	42	+static int menf21bmc_wdt_set_bootstatus(struct menf21bmc_wdt *data)
	43	+{
	44	+ int rst_rsn;
	45	+
	46	+ rst_rsn = i2c_smbus_read_byte_data(data->i2c_client, BMC_CMD_RST_RSN);
	47	+ if (rst_rsn < 0)
	48	+ return rst_rsn;
	49	+
	50	+ if (rst_rsn == 0x02)
	51	+ data->wdt.bootstatus \|= WDIOF_CARDRESET;
	52	+ else if (rst_rsn == 0x05)
	53	+ data->wdt.bootstatus \|= WDIOF_EXTERN1;
	54	+ else if (rst_rsn == 0x06)
	55	+ data->wdt.bootstatus \|= WDIOF_EXTERN2;
	56	+ else if (rst_rsn == 0x0A)
	57	+ data->wdt.bootstatus \|= WDIOF_POWERUNDER;
	58	+
	59	+ return 0;
	60	+}
	61	+
	62	+static int menf21bmc_wdt_start(struct watchdog_device *wdt)
	63	+{
	64	+ struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
	65	+
	66	+ return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_ON);
	67	+}
	68	+
	69	+static int menf21bmc_wdt_stop(struct watchdog_device *wdt)
	70	+{
	71	+ struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
	72	+
	73	+ return i2c_smbus_write_byte_data(drv_data->i2c_client,
	74	+ BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
	75	+}
	76	+
	77	+static int
	78	+menf21bmc_wdt_settimeout(struct watchdog_device *wdt, unsigned int timeout)
	79	+{
	80	+ int ret;
	81	+ struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
	82	+
	83	+ /*
	84	+ * BMC Watchdog does have a resolution of 100ms.
	85	+ * Watchdog API defines the timeout in seconds, so we have to
	86	+ * multiply the value.
	87	+ */
	88	+ ret = i2c_smbus_write_word_data(drv_data->i2c_client,
	89	+ BMC_CMD_WD_TIME, timeout * 10);
	90	+ if (ret < 0)
	91	+ return ret;
	92	+
	93	+ wdt->timeout = timeout;
	94	+
	95	+ return 0;
	96	+}
	97	+
	98	+static int menf21bmc_wdt_ping(struct watchdog_device *wdt)
	99	+{
	100	+ struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
	101	+
	102	+ return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_TRIG);
	103	+}
	104	+
	105	+static const struct watchdog_info menf21bmc_wdt_info = {
	106	+ .options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	107	+ .identity = DEVNAME,
	108	+};
	109	+
	110	+static const struct watchdog_ops menf21bmc_wdt_ops = {
	111	+ .owner = THIS_MODULE,
	112	+ .start = menf21bmc_wdt_start,
	113	+ .stop = menf21bmc_wdt_stop,
	114	+ .ping = menf21bmc_wdt_ping,
	115	+ .set_timeout = menf21bmc_wdt_settimeout,
	116	+};
	117	+
	118	+static int menf21bmc_wdt_probe(struct platform_device *pdev)
	119	+{
	120	+ int ret, bmc_timeout;
	121	+ struct menf21bmc_wdt *drv_data;
	122	+ struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
	123	+
	124	+ drv_data = devm_kzalloc(&pdev->dev,
	125	+ sizeof(struct menf21bmc_wdt), GFP_KERNEL);
	126	+ if (!drv_data)
	127	+ return -ENOMEM;
	128	+
	129	+ drv_data->wdt.ops = &menf21bmc_wdt_ops;
	130	+ drv_data->wdt.info = &menf21bmc_wdt_info;
	131	+ drv_data->wdt.min_timeout = BMC_WD_TIMEOUT_MIN;
	132	+ drv_data->wdt.max_timeout = BMC_WD_TIMEOUT_MAX;
	133	+ drv_data->i2c_client = i2c_client;
	134	+
	135	+ /*
	136	+ * Get the current wdt timeout value from the BMC because
	137	+ * the BMC will save the value set before if the system restarts.
	138	+ */
	139	+ bmc_timeout = i2c_smbus_read_word_data(drv_data->i2c_client,
	140	+ BMC_CMD_WD_TIME);
	141	+ if (bmc_timeout < 0) {
	142	+ dev_err(&pdev->dev, "failed to get current WDT timeout\n");
	143	+ return bmc_timeout;
	144	+ }
	145	+
	146	+ watchdog_init_timeout(&drv_data->wdt, bmc_timeout / 10, &pdev->dev);
	147	+ watchdog_set_nowayout(&drv_data->wdt, nowayout);
	148	+ watchdog_set_drvdata(&drv_data->wdt, drv_data);
	149	+ platform_set_drvdata(pdev, drv_data);
	150	+
	151	+ ret = menf21bmc_wdt_set_bootstatus(drv_data);
	152	+ if (ret < 0) {
	153	+ dev_err(&pdev->dev, "failed to set Watchdog bootstatus\n");
	154	+ return ret;
	155	+ }
	156	+
	157	+ ret = watchdog_register_device(&drv_data->wdt);
	158	+ if (ret) {
	159	+ dev_err(&pdev->dev, "failed to register Watchdog device\n");
	160	+ return ret;
	161	+ }
	162	+
	163	+ dev_info(&pdev->dev, "MEN 14F021P00 BMC Watchdog device enabled\n");
	164	+
	165	+ return 0;
	166	+}
	167	+
	168	+static int menf21bmc_wdt_remove(struct platform_device *pdev)
	169	+{
	170	+ struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
	171	+
	172	+ dev_warn(&pdev->dev,
	173	+ "Unregister MEN 14F021P00 BMC Watchdog device, board may reset\n");
	174	+
	175	+ watchdog_unregister_device(&drv_data->wdt);
	176	+
	177	+ return 0;
	178	+}
	179	+
	180	+static void menf21bmc_wdt_shutdown(struct platform_device *pdev)
	181	+{
	182	+ struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
	183	+
	184	+ i2c_smbus_write_word_data(drv_data->i2c_client,
	185	+ BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
	186	+}
	187	+
	188	+static struct platform_driver menf21bmc_wdt = {
	189	+ .driver = {
	190	+ .owner = THIS_MODULE,
	191	+ .name = DEVNAME,
	192	+ },
	193	+ .probe = menf21bmc_wdt_probe,
	194	+ .remove = menf21bmc_wdt_remove,
	195	+ .shutdown = menf21bmc_wdt_shutdown,
	196	+};
	197	+
	198	+module_platform_driver(menf21bmc_wdt);
	199	+
	200	+MODULE_DESCRIPTION("MEN 14F021P00 BMC Watchdog driver");
	201	+MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
	202	+MODULE_LICENSE("GPL v2");
	203	+MODULE_ALIAS("platform:menf21bmc_wdt");