[linux-2.6-block.git] / drivers / watchdog / atlas7_wdt.c

/*
 * Watchdog driver for CSR Atlas7
 *
 * Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company.
 *
 * Licensed under GPLv2.
 */

#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>

#define ATLAS7_TIMER_WDT_INDEX		5
#define ATLAS7_WDT_DEFAULT_TIMEOUT	20

#define ATLAS7_WDT_CNT_CTRL	(0 + 4 * ATLAS7_TIMER_WDT_INDEX)
#define ATLAS7_WDT_CNT_MATCH	(0x18 + 4 * ATLAS7_TIMER_WDT_INDEX)
#define ATLAS7_WDT_CNT		(0x48 +  4 * ATLAS7_TIMER_WDT_INDEX)
#define ATLAS7_WDT_CNT_EN	(BIT(0) | BIT(1))
#define ATLAS7_WDT_EN		0x64

static unsigned int timeout = ATLAS7_WDT_DEFAULT_TIMEOUT;
static bool nowayout = WATCHDOG_NOWAYOUT;

module_param(timeout, uint, 0);
module_param(nowayout, bool, 0);

MODULE_PARM_DESC(timeout, "Default watchdog timeout (in seconds)");
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
			__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

struct atlas7_wdog {
	struct device *dev;
	void __iomem *base;
	unsigned long tick_rate;
	struct clk *clk;
};

static unsigned int atlas7_wdt_gettimeleft(struct watchdog_device *wdd)
{
	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
	u32 counter, match, delta;

	counter = readl(wdt->base + ATLAS7_WDT_CNT);
	match = readl(wdt->base + ATLAS7_WDT_CNT_MATCH);
	delta = match - counter;

	return  delta / wdt->tick_rate;
}

static int atlas7_wdt_ping(struct watchdog_device *wdd)
{
	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
	u32 counter, match, delta;

	counter = readl(wdt->base + ATLAS7_WDT_CNT);
	delta = wdd->timeout * wdt->tick_rate;
	match = counter + delta;

	writel(match, wdt->base + ATLAS7_WDT_CNT_MATCH);

	return 0;
}

static int atlas7_wdt_enable(struct watchdog_device *wdd)
{
	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);

	atlas7_wdt_ping(wdd);

	writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) | ATLAS7_WDT_CNT_EN,
	      wdt->base + ATLAS7_WDT_CNT_CTRL);
	writel(1, wdt->base + ATLAS7_WDT_EN);

	return 0;
}

static int atlas7_wdt_disable(struct watchdog_device *wdd)
{
	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);

	writel(0, wdt->base + ATLAS7_WDT_EN);
	writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) & ~ATLAS7_WDT_CNT_EN,
	      wdt->base + ATLAS7_WDT_CNT_CTRL);

	return 0;
}

static int atlas7_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
{
	wdd->timeout = to;

	return 0;
}

#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)

static const struct watchdog_info atlas7_wdt_ident = {
	.options = OPTIONS,
	.firmware_version = 0,
	.identity = "atlas7 Watchdog",
};

static const struct watchdog_ops atlas7_wdt_ops = {
	.owner = THIS_MODULE,
	.start = atlas7_wdt_enable,
	.stop = atlas7_wdt_disable,
	.get_timeleft = atlas7_wdt_gettimeleft,
	.ping = atlas7_wdt_ping,
	.set_timeout = atlas7_wdt_settimeout,
};

static struct watchdog_device atlas7_wdd = {
	.info = &atlas7_wdt_ident,
	.ops = &atlas7_wdt_ops,
	.timeout = ATLAS7_WDT_DEFAULT_TIMEOUT,
};

static const struct of_device_id atlas7_wdt_ids[] = {
	{ .compatible = "sirf,atlas7-tick"},
	{}
};

static int atlas7_wdt_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct atlas7_wdog *wdt;
	struct clk *clk;
	int ret;

	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
	if (!wdt)
		return -ENOMEM;
	wdt->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(wdt->base))
		return PTR_ERR(wdt->base);

	clk = of_clk_get(np, 0);
	if (IS_ERR(clk))
		return PTR_ERR(clk);
	ret = clk_prepare_enable(clk);
	if (ret) {
		dev_err(&pdev->dev, "clk enable failed\n");
		goto err;
	}

	/* disable watchdog hardware */
	writel(0, wdt->base + ATLAS7_WDT_CNT_CTRL);

	wdt->tick_rate = clk_get_rate(clk);
	if (!wdt->tick_rate) {
		ret = -EINVAL;
		goto err1;
	}

	wdt->clk = clk;
	atlas7_wdd.min_timeout = 1;
	atlas7_wdd.max_timeout = UINT_MAX / wdt->tick_rate;

	watchdog_init_timeout(&atlas7_wdd, 0, &pdev->dev);
	watchdog_set_nowayout(&atlas7_wdd, nowayout);

	watchdog_set_drvdata(&atlas7_wdd, wdt);
	platform_set_drvdata(pdev, &atlas7_wdd);

	ret = watchdog_register_device(&atlas7_wdd);
	if (ret)
		goto err1;

	return 0;

err1:
	clk_disable_unprepare(clk);
err:
	clk_put(clk);
	return ret;
}

static void atlas7_wdt_shutdown(struct platform_device *pdev)
{
	struct watchdog_device *wdd = platform_get_drvdata(pdev);
	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);

	atlas7_wdt_disable(wdd);
	clk_disable_unprepare(wdt->clk);
}

static int atlas7_wdt_remove(struct platform_device *pdev)
{
	struct watchdog_device *wdd = platform_get_drvdata(pdev);
	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);

	atlas7_wdt_shutdown(pdev);
	clk_put(wdt->clk);
	return 0;
}

static int __maybe_unused atlas7_wdt_suspend(struct device *dev)
{
	/*
	 * NOTE:timer controller registers settings are saved
	 * and restored back by the timer-atlas7.c
	 */
	return 0;
}

static int __maybe_unused atlas7_wdt_resume(struct device *dev)
{
	struct watchdog_device *wdd = dev_get_drvdata(dev);

	/*
	 * NOTE: Since timer controller registers settings are saved
	 * and restored back by the timer-atlas7.c, so we need not
	 * update WD settings except refreshing timeout.
	 */
	atlas7_wdt_ping(wdd);

	return 0;
}

static SIMPLE_DEV_PM_OPS(atlas7_wdt_pm_ops,
		atlas7_wdt_suspend, atlas7_wdt_resume);

MODULE_DEVICE_TABLE(of, atlas7_wdt_ids);

static struct platform_driver atlas7_wdt_driver = {
	.driver = {
		.name = "atlas7-wdt",
		.pm = &atlas7_wdt_pm_ops,
		.of_match_table	= atlas7_wdt_ids,
	},
	.probe = atlas7_wdt_probe,
	.remove = atlas7_wdt_remove,
	.shutdown = atlas7_wdt_shutdown,
};
module_platform_driver(atlas7_wdt_driver);

MODULE_DESCRIPTION("CSRatlas7 watchdog driver");
MODULE_AUTHOR("Guo Zeng <Guo.Zeng@csr.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:atlas7-wdt");
Commit	Line	Data
b466ee89 GZ	1	/*
	2	* Watchdog driver for CSR Atlas7
	3	*
	4	* Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company.
	5	*
	6	* Licensed under GPLv2.
	7	*/
	8
	9	#include <linux/clk.h>
	10	#include <linux/io.h>
	11	#include <linux/module.h>
	12	#include <linux/moduleparam.h>
	13	#include <linux/of.h>
	14	#include <linux/platform_device.h>
	15	#include <linux/watchdog.h>
	16
	17	#define ATLAS7_TIMER_WDT_INDEX 5
	18	#define ATLAS7_WDT_DEFAULT_TIMEOUT 20
	19
	20	#define ATLAS7_WDT_CNT_CTRL (0 + 4 * ATLAS7_TIMER_WDT_INDEX)
	21	#define ATLAS7_WDT_CNT_MATCH (0x18 + 4 * ATLAS7_TIMER_WDT_INDEX)
	22	#define ATLAS7_WDT_CNT (0x48 + 4 * ATLAS7_TIMER_WDT_INDEX)
	23	#define ATLAS7_WDT_CNT_EN (BIT(0) \| BIT(1))
	24	#define ATLAS7_WDT_EN 0x64
	25
	26	static unsigned int timeout = ATLAS7_WDT_DEFAULT_TIMEOUT;
	27	static bool nowayout = WATCHDOG_NOWAYOUT;
	28
	29	module_param(timeout, uint, 0);
	30	module_param(nowayout, bool, 0);
	31
	32	MODULE_PARM_DESC(timeout, "Default watchdog timeout (in seconds)");
	33	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
	34	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	35
	36	struct atlas7_wdog {
	37	struct device *dev;
	38	void __iomem *base;
	39	unsigned long tick_rate;
	40	struct clk *clk;
	41	};
	42
	43	static unsigned int atlas7_wdt_gettimeleft(struct watchdog_device *wdd)
	44	{
	45	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
	46	u32 counter, match, delta;
	47
	48	counter = readl(wdt->base + ATLAS7_WDT_CNT);
	49	match = readl(wdt->base + ATLAS7_WDT_CNT_MATCH);
	50	delta = match - counter;
	51
	52	return delta / wdt->tick_rate;
	53	}
	54
	55	static int atlas7_wdt_ping(struct watchdog_device *wdd)
	56	{
	57	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
	58	u32 counter, match, delta;
	59
	60	counter = readl(wdt->base + ATLAS7_WDT_CNT);
	61	delta = wdd->timeout * wdt->tick_rate;
	62	match = counter + delta;
	63
	64	writel(match, wdt->base + ATLAS7_WDT_CNT_MATCH);
65
66	return 0;
67	}
68
69	static int atlas7_wdt_enable(struct watchdog_device *wdd)
70	{
71	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
72
73	atlas7_wdt_ping(wdd);
74
75	writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) \| ATLAS7_WDT_CNT_EN,
76	wdt->base + ATLAS7_WDT_CNT_CTRL);
77	writel(1, wdt->base + ATLAS7_WDT_EN);
78
79	return 0;
80	}
81
82	static int atlas7_wdt_disable(struct watchdog_device *wdd)
83	{
84	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
85
86	writel(0, wdt->base + ATLAS7_WDT_EN);
87	writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) & ~ATLAS7_WDT_CNT_EN,
88	wdt->base + ATLAS7_WDT_CNT_CTRL);
89
90	return 0;
91	}
92
93	static int atlas7_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
94	{
95	wdd->timeout = to;
96
97	return 0;
98	}
99
100	#define OPTIONS (WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE)
101
102	static const struct watchdog_info atlas7_wdt_ident = {
103	.options = OPTIONS,
104	.firmware_version = 0,
105	.identity = "atlas7 Watchdog",
106	};
107
b893e344	108	static const struct watchdog_ops atlas7_wdt_ops = {
b466ee89 GZ	109	.owner = THIS_MODULE,
	110	.start = atlas7_wdt_enable,
	111	.stop = atlas7_wdt_disable,
	112	.get_timeleft = atlas7_wdt_gettimeleft,
	113	.ping = atlas7_wdt_ping,
	114	.set_timeout = atlas7_wdt_settimeout,
	115	};
	116
	117	static struct watchdog_device atlas7_wdd = {
	118	.info = &atlas7_wdt_ident,
	119	.ops = &atlas7_wdt_ops,
	120	.timeout = ATLAS7_WDT_DEFAULT_TIMEOUT,
	121	};
	122
	123	static const struct of_device_id atlas7_wdt_ids[] = {
	124	{ .compatible = "sirf,atlas7-tick"},
	125	{}
	126	};
	127
	128	static int atlas7_wdt_probe(struct platform_device *pdev)
	129	{
	130	struct device_node *np = pdev->dev.of_node;
	131	struct atlas7_wdog *wdt;
b466ee89 GZ	132	struct clk *clk;
	133	int ret;
	134
	135	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
	136	if (!wdt)
	137	return -ENOMEM;
0f0a6a28	138	wdt->base = devm_platform_ioremap_resource(pdev, 0);
b466ee89 GZ	139	if (IS_ERR(wdt->base))
	140	return PTR_ERR(wdt->base);
	141
	142	clk = of_clk_get(np, 0);
	143	if (IS_ERR(clk))
	144	return PTR_ERR(clk);
	145	ret = clk_prepare_enable(clk);
	146	if (ret) {
	147	dev_err(&pdev->dev, "clk enable failed\n");
	148	goto err;
	149	}
	150
	151	/* disable watchdog hardware */
	152	writel(0, wdt->base + ATLAS7_WDT_CNT_CTRL);
	153
	154	wdt->tick_rate = clk_get_rate(clk);
ccc8208d WS	155	if (!wdt->tick_rate) {
	156	ret = -EINVAL;
	157	goto err1;
	158	}
	159
b466ee89 GZ	160	wdt->clk = clk;
	161	atlas7_wdd.min_timeout = 1;
	162	atlas7_wdd.max_timeout = UINT_MAX / wdt->tick_rate;
	163
	164	watchdog_init_timeout(&atlas7_wdd, 0, &pdev->dev);
	165	watchdog_set_nowayout(&atlas7_wdd, nowayout);
	166
	167	watchdog_set_drvdata(&atlas7_wdd, wdt);
	168	platform_set_drvdata(pdev, &atlas7_wdd);
	169
	170	ret = watchdog_register_device(&atlas7_wdd);
	171	if (ret)
	172	goto err1;
	173
	174	return 0;
	175
	176	err1:
	177	clk_disable_unprepare(clk);
	178	err:
	179	clk_put(clk);
	180	return ret;
	181	}
	182
	183	static void atlas7_wdt_shutdown(struct platform_device *pdev)
	184	{
	185	struct watchdog_device *wdd = platform_get_drvdata(pdev);
	186	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
	187
	188	atlas7_wdt_disable(wdd);
	189	clk_disable_unprepare(wdt->clk);
	190	}
	191
	192	static int atlas7_wdt_remove(struct platform_device *pdev)
	193	{
	194	struct watchdog_device *wdd = platform_get_drvdata(pdev);
	195	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
	196
	197	atlas7_wdt_shutdown(pdev);
	198	clk_put(wdt->clk);
	199	return 0;
	200	}
	201
	202	static int __maybe_unused atlas7_wdt_suspend(struct device *dev)
	203	{
	204	/*
	205	* NOTE:timer controller registers settings are saved
	206	* and restored back by the timer-atlas7.c
	207	*/
	208	return 0;
	209	}
	210
	211	static int __maybe_unused atlas7_wdt_resume(struct device *dev)
	212	{
	213	struct watchdog_device *wdd = dev_get_drvdata(dev);
	214
	215	/*
	216	* NOTE: Since timer controller registers settings are saved
	217	* and restored back by the timer-atlas7.c, so we need not
	218	* update WD settings except refreshing timeout.
	219	*/
	220	atlas7_wdt_ping(wdd);
	221
	222	return 0;
	223	}
224
225	static SIMPLE_DEV_PM_OPS(atlas7_wdt_pm_ops,
226	atlas7_wdt_suspend, atlas7_wdt_resume);
227
228	MODULE_DEVICE_TABLE(of, atlas7_wdt_ids);
229
230	static struct platform_driver atlas7_wdt_driver = {
231	.driver = {
232	.name = "atlas7-wdt",
233	.pm = &atlas7_wdt_pm_ops,
234	.of_match_table = atlas7_wdt_ids,
235	},
236	.probe = atlas7_wdt_probe,
237	.remove = atlas7_wdt_remove,
238	.shutdown = atlas7_wdt_shutdown,
239	};
240	module_platform_driver(atlas7_wdt_driver);
241
242	MODULE_DESCRIPTION("CSRatlas7 watchdog driver");
243	MODULE_AUTHOR("Guo Zeng <Guo.Zeng@csr.com>");
244	MODULE_LICENSE("GPL v2");
245	MODULE_ALIAS("platform:atlas7-wdt");