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

// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
 * Copyright (c) 2016 BayLibre, SAS.
 * Author: Neil Armstrong <narmstrong@baylibre.com>
 *
 */
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/watchdog.h>

#define DEFAULT_TIMEOUT	30	/* seconds */

#define GXBB_WDT_CTRL_REG			0x0
#define GXBB_WDT_TCNT_REG			0x8
#define GXBB_WDT_RSET_REG			0xc

#define GXBB_WDT_CTRL_CLKDIV_EN			BIT(25)
#define GXBB_WDT_CTRL_CLK_EN			BIT(24)
#define GXBB_WDT_CTRL_EE_RESET			BIT(21)
#define GXBB_WDT_CTRL_EN			BIT(18)
#define GXBB_WDT_CTRL_DIV_MASK			(BIT(18) - 1)

#define GXBB_WDT_TCNT_SETUP_MASK		(BIT(16) - 1)
#define GXBB_WDT_TCNT_CNT_SHIFT			16

struct meson_gxbb_wdt {
	void __iomem *reg_base;
	struct watchdog_device wdt_dev;
	struct clk *clk;
};

static int meson_gxbb_wdt_start(struct watchdog_device *wdt_dev)
{
	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);

	writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) | GXBB_WDT_CTRL_EN,
	       data->reg_base + GXBB_WDT_CTRL_REG);

	return 0;
}

static int meson_gxbb_wdt_stop(struct watchdog_device *wdt_dev)
{
	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);

	writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN,
	       data->reg_base + GXBB_WDT_CTRL_REG);

	return 0;
}

static int meson_gxbb_wdt_ping(struct watchdog_device *wdt_dev)
{
	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);

	writel(0, data->reg_base + GXBB_WDT_RSET_REG);

	return 0;
}

static int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev,
				      unsigned int timeout)
{
	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
	unsigned long tcnt = timeout * 1000;

	if (tcnt > GXBB_WDT_TCNT_SETUP_MASK)
		tcnt = GXBB_WDT_TCNT_SETUP_MASK;

	wdt_dev->timeout = timeout;

	meson_gxbb_wdt_ping(wdt_dev);

	writel(tcnt, data->reg_base + GXBB_WDT_TCNT_REG);

	return 0;
}

static unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev)
{
	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
	unsigned long reg;

	reg = readl(data->reg_base + GXBB_WDT_TCNT_REG);

	return ((reg >> GXBB_WDT_TCNT_CNT_SHIFT) -
		(reg & GXBB_WDT_TCNT_SETUP_MASK)) / 1000;
}

static const struct watchdog_ops meson_gxbb_wdt_ops = {
	.start = meson_gxbb_wdt_start,
	.stop = meson_gxbb_wdt_stop,
	.ping = meson_gxbb_wdt_ping,
	.set_timeout = meson_gxbb_wdt_set_timeout,
	.get_timeleft = meson_gxbb_wdt_get_timeleft,
};

static const struct watchdog_info meson_gxbb_wdt_info = {
	.identity = "Meson GXBB Watchdog",
	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
};

static int __maybe_unused meson_gxbb_wdt_resume(struct device *dev)
{
	struct meson_gxbb_wdt *data = dev_get_drvdata(dev);

	if (watchdog_active(&data->wdt_dev))
		meson_gxbb_wdt_start(&data->wdt_dev);

	return 0;
}

static int __maybe_unused meson_gxbb_wdt_suspend(struct device *dev)
{
	struct meson_gxbb_wdt *data = dev_get_drvdata(dev);

	if (watchdog_active(&data->wdt_dev))
		meson_gxbb_wdt_stop(&data->wdt_dev);

	return 0;
}

static const struct dev_pm_ops meson_gxbb_wdt_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(meson_gxbb_wdt_suspend, meson_gxbb_wdt_resume)
};

static const struct of_device_id meson_gxbb_wdt_dt_ids[] = {
	 { .compatible = "amlogic,meson-gxbb-wdt", },
	 { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, meson_gxbb_wdt_dt_ids);

static int meson_gxbb_wdt_probe(struct platform_device *pdev)
{
	struct meson_gxbb_wdt *data;
	int ret;

	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->reg_base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(data->reg_base))
		return PTR_ERR(data->reg_base);

	data->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(data->clk))
		return PTR_ERR(data->clk);

	ret = clk_prepare_enable(data->clk);
	if (ret)
		return ret;

	platform_set_drvdata(pdev, data);

	data->wdt_dev.parent = &pdev->dev;
	data->wdt_dev.info = &meson_gxbb_wdt_info;
	data->wdt_dev.ops = &meson_gxbb_wdt_ops;
	data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK;
	data->wdt_dev.min_timeout = 1;
	data->wdt_dev.timeout = DEFAULT_TIMEOUT;
	watchdog_set_drvdata(&data->wdt_dev, data);

	/* Setup with 1ms timebase */
	writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) |
		GXBB_WDT_CTRL_EE_RESET |
		GXBB_WDT_CTRL_CLK_EN |
		GXBB_WDT_CTRL_CLKDIV_EN,
		data->reg_base + GXBB_WDT_CTRL_REG);

	meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);

	ret = watchdog_register_device(&data->wdt_dev);
	if (ret) {
		clk_disable_unprepare(data->clk);
		return ret;
	}

	return 0;
}

static int meson_gxbb_wdt_remove(struct platform_device *pdev)
{
	struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);

	watchdog_unregister_device(&data->wdt_dev);

	clk_disable_unprepare(data->clk);

	return 0;
}

static void meson_gxbb_wdt_shutdown(struct platform_device *pdev)
{
	struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);

	meson_gxbb_wdt_stop(&data->wdt_dev);
}

static struct platform_driver meson_gxbb_wdt_driver = {
	.probe	= meson_gxbb_wdt_probe,
	.remove	= meson_gxbb_wdt_remove,
	.shutdown = meson_gxbb_wdt_shutdown,
	.driver = {
		.name = "meson-gxbb-wdt",
		.pm = &meson_gxbb_wdt_pm_ops,
		.of_match_table	= meson_gxbb_wdt_dt_ids,
	},
};

module_platform_driver(meson_gxbb_wdt_driver);

MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver");
MODULE_LICENSE("Dual BSD/GPL");
Commit	Line	Data
2e62c498	1	// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
683fa50f	2	/*
683fa50f NA	3	* Copyright (c) 2016 BayLibre, SAS.
	4	* Author: Neil Armstrong <narmstrong@baylibre.com>
	5	*
683fa50f NA	6	*/
	7	#include <linux/clk.h>
	8	#include <linux/err.h>
	9	#include <linux/io.h>
	10	#include <linux/module.h>
	11	#include <linux/of.h>
	12	#include <linux/platform_device.h>
	13	#include <linux/slab.h>
	14	#include <linux/types.h>
	15	#include <linux/watchdog.h>
	16
	17	#define DEFAULT_TIMEOUT 30 /* seconds */
	18
	19	#define GXBB_WDT_CTRL_REG 0x0
	20	#define GXBB_WDT_TCNT_REG 0x8
	21	#define GXBB_WDT_RSET_REG 0xc
	22
	23	#define GXBB_WDT_CTRL_CLKDIV_EN BIT(25)
	24	#define GXBB_WDT_CTRL_CLK_EN BIT(24)
	25	#define GXBB_WDT_CTRL_EE_RESET BIT(21)
	26	#define GXBB_WDT_CTRL_EN BIT(18)
	27	#define GXBB_WDT_CTRL_DIV_MASK (BIT(18) - 1)
	28
	29	#define GXBB_WDT_TCNT_SETUP_MASK (BIT(16) - 1)
	30	#define GXBB_WDT_TCNT_CNT_SHIFT 16
	31
	32	struct meson_gxbb_wdt {
	33	void __iomem *reg_base;
	34	struct watchdog_device wdt_dev;
	35	struct clk *clk;
	36	};
	37
	38	static int meson_gxbb_wdt_start(struct watchdog_device *wdt_dev)
	39	{
	40	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
	41
	42	writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) \| GXBB_WDT_CTRL_EN,
	43	data->reg_base + GXBB_WDT_CTRL_REG);
	44
	45	return 0;
	46	}
	47
	48	static int meson_gxbb_wdt_stop(struct watchdog_device *wdt_dev)
	49	{
	50	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
	51
	52	writel(readl(data->reg_base + GXBB_WDT_CTRL_REG) & ~GXBB_WDT_CTRL_EN,
	53	data->reg_base + GXBB_WDT_CTRL_REG);
	54
	55	return 0;
	56	}
	57
	58	static int meson_gxbb_wdt_ping(struct watchdog_device *wdt_dev)
	59	{
	60	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
	61
	62	writel(0, data->reg_base + GXBB_WDT_RSET_REG);
	63
	64	return 0;
	65	}
	66
	67	static int meson_gxbb_wdt_set_timeout(struct watchdog_device *wdt_dev,
	68	unsigned int timeout)
	69	{
70	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
71	unsigned long tcnt = timeout * 1000;
72
73	if (tcnt > GXBB_WDT_TCNT_SETUP_MASK)
74	tcnt = GXBB_WDT_TCNT_SETUP_MASK;
75
76	wdt_dev->timeout = timeout;
77
78	meson_gxbb_wdt_ping(wdt_dev);
79
80	writel(tcnt, data->reg_base + GXBB_WDT_TCNT_REG);
81
82	return 0;
83	}
84
85	static unsigned int meson_gxbb_wdt_get_timeleft(struct watchdog_device *wdt_dev)
86	{
87	struct meson_gxbb_wdt *data = watchdog_get_drvdata(wdt_dev);
88	unsigned long reg;
89
90	reg = readl(data->reg_base + GXBB_WDT_TCNT_REG);
91
92	return ((reg >> GXBB_WDT_TCNT_CNT_SHIFT) -
93	(reg & GXBB_WDT_TCNT_SETUP_MASK)) / 1000;
94	}
95
96	static const struct watchdog_ops meson_gxbb_wdt_ops = {
97	.start = meson_gxbb_wdt_start,
98	.stop = meson_gxbb_wdt_stop,
99	.ping = meson_gxbb_wdt_ping,
100	.set_timeout = meson_gxbb_wdt_set_timeout,
101	.get_timeleft = meson_gxbb_wdt_get_timeleft,
102	};
103
104	static const struct watchdog_info meson_gxbb_wdt_info = {
105	.identity = "Meson GXBB Watchdog",
106	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
107	};
108
109	static int __maybe_unused meson_gxbb_wdt_resume(struct device *dev)
110	{
111	struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
112
113	if (watchdog_active(&data->wdt_dev))
114	meson_gxbb_wdt_start(&data->wdt_dev);
115
116	return 0;
117	}
118
119	static int __maybe_unused meson_gxbb_wdt_suspend(struct device *dev)
120	{
121	struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
122
123	if (watchdog_active(&data->wdt_dev))
124	meson_gxbb_wdt_stop(&data->wdt_dev);
125
126	return 0;
127	}
128
129	static const struct dev_pm_ops meson_gxbb_wdt_pm_ops = {
130	SET_SYSTEM_SLEEP_PM_OPS(meson_gxbb_wdt_suspend, meson_gxbb_wdt_resume)
131	};
132
133	static const struct of_device_id meson_gxbb_wdt_dt_ids[] = {
134	{ .compatible = "amlogic,meson-gxbb-wdt", },
135	{ /* sentinel */ },
136	};
137	MODULE_DEVICE_TABLE(of, meson_gxbb_wdt_dt_ids);
138
139	static int meson_gxbb_wdt_probe(struct platform_device *pdev)
140	{
141	struct meson_gxbb_wdt *data;
683fa50f NA	142	int ret;
	143
	144	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	145	if (!data)
	146	return -ENOMEM;
	147
0f0a6a28	148	data->reg_base = devm_platform_ioremap_resource(pdev, 0);
683fa50f NA	149	if (IS_ERR(data->reg_base))
	150	return PTR_ERR(data->reg_base);
	151
	152	data->clk = devm_clk_get(&pdev->dev, NULL);
	153	if (IS_ERR(data->clk))
	154	return PTR_ERR(data->clk);
	155
65360944 AY	156	ret = clk_prepare_enable(data->clk);
	157	if (ret)
	158	return ret;
683fa50f NA	159
	160	platform_set_drvdata(pdev, data);
	161
	162	data->wdt_dev.parent = &pdev->dev;
	163	data->wdt_dev.info = &meson_gxbb_wdt_info;
	164	data->wdt_dev.ops = &meson_gxbb_wdt_ops;
	165	data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK;
	166	data->wdt_dev.min_timeout = 1;
	167	data->wdt_dev.timeout = DEFAULT_TIMEOUT;
	168	watchdog_set_drvdata(&data->wdt_dev, data);
	169
	170	/* Setup with 1ms timebase */
	171	writel(((clk_get_rate(data->clk) / 1000) & GXBB_WDT_CTRL_DIV_MASK) \|
	172	GXBB_WDT_CTRL_EE_RESET \|
	173	GXBB_WDT_CTRL_CLK_EN \|
	174	GXBB_WDT_CTRL_CLKDIV_EN,
	175	data->reg_base + GXBB_WDT_CTRL_REG);
	176
	177	meson_gxbb_wdt_set_timeout(&data->wdt_dev, data->wdt_dev.timeout);
	178
	179	ret = watchdog_register_device(&data->wdt_dev);
	180	if (ret) {
	181	clk_disable_unprepare(data->clk);
	182	return ret;
	183	}
	184
	185	return 0;
	186	}
	187
	188	static int meson_gxbb_wdt_remove(struct platform_device *pdev)
	189	{
	190	struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);
	191
	192	watchdog_unregister_device(&data->wdt_dev);
	193
	194	clk_disable_unprepare(data->clk);
	195
	196	return 0;
	197	}
	198
	199	static void meson_gxbb_wdt_shutdown(struct platform_device *pdev)
	200	{
	201	struct meson_gxbb_wdt *data = platform_get_drvdata(pdev);
	202
	203	meson_gxbb_wdt_stop(&data->wdt_dev);
	204	}
	205
	206	static struct platform_driver meson_gxbb_wdt_driver = {
	207	.probe = meson_gxbb_wdt_probe,
	208	.remove = meson_gxbb_wdt_remove,
	209	.shutdown = meson_gxbb_wdt_shutdown,
	210	.driver = {
	211	.name = "meson-gxbb-wdt",
	212	.pm = &meson_gxbb_wdt_pm_ops,
	213	.of_match_table = meson_gxbb_wdt_dt_ids,
	214	},
	215	};
	216
	217	module_platform_driver(meson_gxbb_wdt_driver);
	218
683fa50f NA	219	MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
	220	MODULE_DESCRIPTION("Amlogic Meson GXBB Watchdog timer driver");
	221	MODULE_LICENSE("Dual BSD/GPL");