[deliverable/linux.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 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 resource *res;
	struct clk *clk;
	int ret;

	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
	if (!wdt)
		return -ENOMEM;
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	wdt->base = devm_ioremap_resource(&pdev->dev, res);
	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);
	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
108	static struct watchdog_ops atlas7_wdt_ops = {
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;
132	struct resource *res;
133	struct clk *clk;
134	int ret;
135
136	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
137	if (!wdt)
138	return -ENOMEM;
139	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
140	wdt->base = devm_ioremap_resource(&pdev->dev, res);
141	if (IS_ERR(wdt->base))
142	return PTR_ERR(wdt->base);
143
144	clk = of_clk_get(np, 0);
145	if (IS_ERR(clk))
146	return PTR_ERR(clk);
147	ret = clk_prepare_enable(clk);
148	if (ret) {
149	dev_err(&pdev->dev, "clk enable failed\n");
150	goto err;
151	}
152
153	/* disable watchdog hardware */
154	writel(0, wdt->base + ATLAS7_WDT_CNT_CTRL);
155
156	wdt->tick_rate = clk_get_rate(clk);
157	wdt->clk = clk;
158	atlas7_wdd.min_timeout = 1;
159	atlas7_wdd.max_timeout = UINT_MAX / wdt->tick_rate;
160
161	watchdog_init_timeout(&atlas7_wdd, 0, &pdev->dev);
162	watchdog_set_nowayout(&atlas7_wdd, nowayout);
163
164	watchdog_set_drvdata(&atlas7_wdd, wdt);
165	platform_set_drvdata(pdev, &atlas7_wdd);
166
167	ret = watchdog_register_device(&atlas7_wdd);
168	if (ret)
169	goto err1;
170
171	return 0;
172
173	err1:
174	clk_disable_unprepare(clk);
175	err:
176	clk_put(clk);
177	return ret;
178	}
179
180	static void atlas7_wdt_shutdown(struct platform_device *pdev)
181	{
182	struct watchdog_device *wdd = platform_get_drvdata(pdev);
183	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
184
185	atlas7_wdt_disable(wdd);
186	clk_disable_unprepare(wdt->clk);
187	}
188
189	static int atlas7_wdt_remove(struct platform_device *pdev)
190	{
191	struct watchdog_device *wdd = platform_get_drvdata(pdev);
192	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
193
194	atlas7_wdt_shutdown(pdev);
195	clk_put(wdt->clk);
196	return 0;
197	}
198
199	static int __maybe_unused atlas7_wdt_suspend(struct device *dev)
200	{
201	/*
202	* NOTE:timer controller registers settings are saved
203	* and restored back by the timer-atlas7.c
204	*/
205	return 0;
206	}
207
208	static int __maybe_unused atlas7_wdt_resume(struct device *dev)
209	{
210	struct watchdog_device *wdd = dev_get_drvdata(dev);
211
212	/*
213	* NOTE: Since timer controller registers settings are saved
214	* and restored back by the timer-atlas7.c, so we need not
215	* update WD settings except refreshing timeout.
216	*/
217	atlas7_wdt_ping(wdd);
218
219	return 0;
220	}
221
222	static SIMPLE_DEV_PM_OPS(atlas7_wdt_pm_ops,
223	atlas7_wdt_suspend, atlas7_wdt_resume);
224
225	MODULE_DEVICE_TABLE(of, atlas7_wdt_ids);
226
227	static struct platform_driver atlas7_wdt_driver = {
228	.driver = {
229	.name = "atlas7-wdt",
230	.pm = &atlas7_wdt_pm_ops,
231	.of_match_table = atlas7_wdt_ids,
232	},
233	.probe = atlas7_wdt_probe,
234	.remove = atlas7_wdt_remove,
235	.shutdown = atlas7_wdt_shutdown,
236	};
237	module_platform_driver(atlas7_wdt_driver);
238
239	MODULE_DESCRIPTION("CSRatlas7 watchdog driver");
240	MODULE_AUTHOR("Guo Zeng <Guo.Zeng@csr.com>");
241	MODULE_LICENSE("GPL v2");
242	MODULE_ALIAS("platform:atlas7-wdt");