[linux-2.6-block.git] / drivers / watchdog / menf21bmc_wdt.c

/*
 *  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		= {
		.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");
Commit	Line	Data
50332639 AW	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 = {
50332639 AW	190	.name = DEVNAME,
	191	},
	192	.probe = menf21bmc_wdt_probe,
	193	.remove = menf21bmc_wdt_remove,
	194	.shutdown = menf21bmc_wdt_shutdown,
	195	};
	196
	197	module_platform_driver(menf21bmc_wdt);
	198
	199	MODULE_DESCRIPTION("MEN 14F021P00 BMC Watchdog driver");
	200	MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
	201	MODULE_LICENSE("GPL v2");
	202	MODULE_ALIAS("platform:menf21bmc_wdt");