[mirror_ubuntu-bionic-kernel.git] / drivers / rtc / rtc-brcmstb-waketimer.c

/*
 * Copyright © 2014-2017 Broadcom
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

#include <linux/clk.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irqreturn.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/pm_wakeup.h>
#include <linux/reboot.h>
#include <linux/rtc.h>
#include <linux/stat.h>
#include <linux/suspend.h>

struct brcmstb_waketmr {
	struct rtc_device *rtc;
	struct device *dev;
	void __iomem *base;
	int irq;
	struct notifier_block reboot_notifier;
	struct clk *clk;
	u32 rate;
};

#define BRCMSTB_WKTMR_EVENT		0x00
#define BRCMSTB_WKTMR_COUNTER		0x04
#define BRCMSTB_WKTMR_ALARM		0x08
#define BRCMSTB_WKTMR_PRESCALER		0x0C
#define BRCMSTB_WKTMR_PRESCALER_VAL	0x10

#define BRCMSTB_WKTMR_DEFAULT_FREQ	27000000

static inline void brcmstb_waketmr_clear_alarm(struct brcmstb_waketmr *timer)
{
	writel_relaxed(1, timer->base + BRCMSTB_WKTMR_EVENT);
	(void)readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
}

static void brcmstb_waketmr_set_alarm(struct brcmstb_waketmr *timer,
				      unsigned int secs)
{
	brcmstb_waketmr_clear_alarm(timer);

	writel_relaxed(secs + 1, timer->base + BRCMSTB_WKTMR_ALARM);
}

static irqreturn_t brcmstb_waketmr_irq(int irq, void *data)
{
	struct brcmstb_waketmr *timer = data;

	pm_wakeup_event(timer->dev, 0);

	return IRQ_HANDLED;
}

struct wktmr_time {
	u32 sec;
	u32 pre;
};

static void wktmr_read(struct brcmstb_waketmr *timer,
		       struct wktmr_time *t)
{
	u32 tmp;

	do {
		t->sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER);
		tmp = readl_relaxed(timer->base + BRCMSTB_WKTMR_PRESCALER_VAL);
	} while (tmp >= timer->rate);

	t->pre = timer->rate - tmp;
}

static int brcmstb_waketmr_prepare_suspend(struct brcmstb_waketmr *timer)
{
	struct device *dev = timer->dev;
	int ret = 0;

	if (device_may_wakeup(dev)) {
		ret = enable_irq_wake(timer->irq);
		if (ret) {
			dev_err(dev, "failed to enable wake-up interrupt\n");
			return ret;
		}
	}

	return ret;
}

/* If enabled as a wakeup-source, arm the timer when powering off */
static int brcmstb_waketmr_reboot(struct notifier_block *nb,
		unsigned long action, void *data)
{
	struct brcmstb_waketmr *timer;

	timer = container_of(nb, struct brcmstb_waketmr, reboot_notifier);

	/* Set timer for cold boot */
	if (action == SYS_POWER_OFF)
		brcmstb_waketmr_prepare_suspend(timer);

	return NOTIFY_DONE;
}

static int brcmstb_waketmr_gettime(struct device *dev,
				   struct rtc_time *tm)
{
	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
	struct wktmr_time now;

	wktmr_read(timer, &now);

	rtc_time_to_tm(now.sec, tm);

	return 0;
}

static int brcmstb_waketmr_settime(struct device *dev,
				   struct rtc_time *tm)
{
	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
	time64_t sec;

	sec = rtc_tm_to_time64(tm);

	if (sec > U32_MAX || sec < 0)
		return -EINVAL;

	writel_relaxed(sec, timer->base + BRCMSTB_WKTMR_COUNTER);

	return 0;
}

static int brcmstb_waketmr_getalarm(struct device *dev,
				    struct rtc_wkalrm *alarm)
{
	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
	time64_t sec;
	u32 reg;

	sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_ALARM);
	if (sec != 0) {
		/* Alarm is enabled */
		alarm->enabled = 1;
		rtc_time64_to_tm(sec, &alarm->time);
	}

	reg = readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
	alarm->pending = !!(reg & 1);

	return 0;
}

static int brcmstb_waketmr_setalarm(struct device *dev,
				     struct rtc_wkalrm *alarm)
{
	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
	time64_t sec;

	if (alarm->enabled)
		sec = rtc_tm_to_time64(&alarm->time);
	else
		sec = 0;

	if (sec > U32_MAX || sec < 0)
		return -EINVAL;

	brcmstb_waketmr_set_alarm(timer, sec);

	return 0;
}

/*
 * Does not do much but keep the RTC class happy. We always support
 * alarms.
 */
static int brcmstb_waketmr_alarm_enable(struct device *dev,
					unsigned int enabled)
{
	return 0;
}

static const struct rtc_class_ops brcmstb_waketmr_ops = {
	.read_time	= brcmstb_waketmr_gettime,
	.set_time	= brcmstb_waketmr_settime,
	.read_alarm	= brcmstb_waketmr_getalarm,
	.set_alarm	= brcmstb_waketmr_setalarm,
	.alarm_irq_enable = brcmstb_waketmr_alarm_enable,
};

static int brcmstb_waketmr_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct brcmstb_waketmr *timer;
	struct resource *res;
	int ret;

	timer = devm_kzalloc(dev, sizeof(*timer), GFP_KERNEL);
	if (!timer)
		return -ENOMEM;

	platform_set_drvdata(pdev, timer);
	timer->dev = dev;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	timer->base = devm_ioremap_resource(dev, res);
	if (IS_ERR(timer->base))
		return PTR_ERR(timer->base);

	/*
	 * Set wakeup capability before requesting wakeup interrupt, so we can
	 * process boot-time "wakeups" (e.g., from S5 soft-off)
	 */
	device_set_wakeup_capable(dev, true);
	device_wakeup_enable(dev);

	timer->irq = platform_get_irq(pdev, 0);
	if (timer->irq < 0)
		return -ENODEV;

	timer->clk = devm_clk_get(dev, NULL);
	if (!IS_ERR(timer->clk)) {
		ret = clk_prepare_enable(timer->clk);
		if (ret)
			return ret;
		timer->rate = clk_get_rate(timer->clk);
		if (!timer->rate)
			timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
	} else {
		timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
		timer->clk = NULL;
	}

	ret = devm_request_irq(dev, timer->irq, brcmstb_waketmr_irq, 0,
			       "brcmstb-waketimer", timer);
	if (ret < 0)
		goto err_clk;

	timer->reboot_notifier.notifier_call = brcmstb_waketmr_reboot;
	register_reboot_notifier(&timer->reboot_notifier);

	timer->rtc = rtc_device_register("brcmstb-waketmr", dev,
					 &brcmstb_waketmr_ops, THIS_MODULE);
	if (IS_ERR(timer->rtc)) {
		dev_err(dev, "unable to register device\n");
		ret = PTR_ERR(timer->rtc);
		goto err_notifier;
	}

	dev_info(dev, "registered, with irq %d\n", timer->irq);

	return 0;

err_notifier:
	unregister_reboot_notifier(&timer->reboot_notifier);
	clk_disable_unprepare(timer->clk);

err_clk:
	if (timer->clk)
		clk_disable_unprepare(timer->clk);

	return ret;
}

static int brcmstb_waketmr_remove(struct platform_device *pdev)
{
	struct brcmstb_waketmr *timer = dev_get_drvdata(&pdev->dev);

	unregister_reboot_notifier(&timer->reboot_notifier);
	rtc_device_unregister(timer->rtc);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int brcmstb_waketmr_suspend(struct device *dev)
{
	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);

	return brcmstb_waketmr_prepare_suspend(timer);
}

static int brcmstb_waketmr_resume(struct device *dev)
{
	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
	int ret;

	if (!device_may_wakeup(dev))
		return 0;

	ret = disable_irq_wake(timer->irq);

	brcmstb_waketmr_clear_alarm(timer);

	return ret;
}
#endif /* CONFIG_PM_SLEEP */

static SIMPLE_DEV_PM_OPS(brcmstb_waketmr_pm_ops,
			 brcmstb_waketmr_suspend, brcmstb_waketmr_resume);

static const struct of_device_id brcmstb_waketmr_of_match[] = {
	{ .compatible = "brcm,brcmstb-waketimer" },
	{ /* sentinel */ },
};

static struct platform_driver brcmstb_waketmr_driver = {
	.probe			= brcmstb_waketmr_probe,
	.remove			= brcmstb_waketmr_remove,
	.driver = {
		.name		= "brcmstb-waketimer",
		.pm		= &brcmstb_waketmr_pm_ops,
		.of_match_table	= of_match_ptr(brcmstb_waketmr_of_match),
	}
};
module_platform_driver(brcmstb_waketmr_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Brian Norris");
MODULE_AUTHOR("Markus Mayer");
MODULE_DESCRIPTION("Wake-up timer driver for STB chips");
Commit	Line	Data
c4f07ece BN	1	/*
	2	* Copyright © 2014-2017 Broadcom
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	11	* GNU General Public License for more details.
	12	*/
	13
	14	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	15
	16	#include <linux/clk.h>
	17	#include <linux/device.h>
	18	#include <linux/err.h>
	19	#include <linux/init.h>
	20	#include <linux/interrupt.h>
	21	#include <linux/io.h>
	22	#include <linux/irqreturn.h>
	23	#include <linux/kernel.h>
	24	#include <linux/module.h>
	25	#include <linux/of.h>
	26	#include <linux/platform_device.h>
	27	#include <linux/pm.h>
	28	#include <linux/pm_wakeup.h>
	29	#include <linux/reboot.h>
	30	#include <linux/rtc.h>
	31	#include <linux/stat.h>
	32	#include <linux/suspend.h>
	33
	34	struct brcmstb_waketmr {
	35	struct rtc_device *rtc;
	36	struct device *dev;
	37	void __iomem *base;
	38	int irq;
	39	struct notifier_block reboot_notifier;
	40	struct clk *clk;
	41	u32 rate;
	42	};
	43
	44	#define BRCMSTB_WKTMR_EVENT 0x00
	45	#define BRCMSTB_WKTMR_COUNTER 0x04
	46	#define BRCMSTB_WKTMR_ALARM 0x08
	47	#define BRCMSTB_WKTMR_PRESCALER 0x0C
	48	#define BRCMSTB_WKTMR_PRESCALER_VAL 0x10
	49
	50	#define BRCMSTB_WKTMR_DEFAULT_FREQ 27000000
	51
	52	static inline void brcmstb_waketmr_clear_alarm(struct brcmstb_waketmr *timer)
	53	{
	54	writel_relaxed(1, timer->base + BRCMSTB_WKTMR_EVENT);
	55	(void)readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
	56	}
	57
	58	static void brcmstb_waketmr_set_alarm(struct brcmstb_waketmr *timer,
	59	unsigned int secs)
	60	{
	61	brcmstb_waketmr_clear_alarm(timer);
	62
	63	writel_relaxed(secs + 1, timer->base + BRCMSTB_WKTMR_ALARM);
	64	}
65
66	static irqreturn_t brcmstb_waketmr_irq(int irq, void *data)
67	{
68	struct brcmstb_waketmr *timer = data;
69
70	pm_wakeup_event(timer->dev, 0);
71
72	return IRQ_HANDLED;
73	}
74
75	struct wktmr_time {
76	u32 sec;
77	u32 pre;
78	};
79
80	static void wktmr_read(struct brcmstb_waketmr *timer,
81	struct wktmr_time *t)
82	{
83	u32 tmp;
84
85	do {
86	t->sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER);
87	tmp = readl_relaxed(timer->base + BRCMSTB_WKTMR_PRESCALER_VAL);
88	} while (tmp >= timer->rate);
89
90	t->pre = timer->rate - tmp;
91	}
92
93	static int brcmstb_waketmr_prepare_suspend(struct brcmstb_waketmr *timer)
94	{
95	struct device *dev = timer->dev;
96	int ret = 0;
97
98	if (device_may_wakeup(dev)) {
99	ret = enable_irq_wake(timer->irq);
100	if (ret) {
101	dev_err(dev, "failed to enable wake-up interrupt\n");
102	return ret;
103	}
104	}
105
106	return ret;
107	}
108
109	/* If enabled as a wakeup-source, arm the timer when powering off */
110	static int brcmstb_waketmr_reboot(struct notifier_block *nb,
111	unsigned long action, void *data)
112	{
113	struct brcmstb_waketmr *timer;
114
115	timer = container_of(nb, struct brcmstb_waketmr, reboot_notifier);
116
117	/* Set timer for cold boot */
118	if (action == SYS_POWER_OFF)
119	brcmstb_waketmr_prepare_suspend(timer);
120
121	return NOTIFY_DONE;
122	}
123
124	static int brcmstb_waketmr_gettime(struct device *dev,
125	struct rtc_time *tm)
126	{
127	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
128	struct wktmr_time now;
129
130	wktmr_read(timer, &now);
131
132	rtc_time_to_tm(now.sec, tm);
133
134	return 0;
135	}
136
137	static int brcmstb_waketmr_settime(struct device *dev,
138	struct rtc_time *tm)
139	{
140	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
141	time64_t sec;
142
143	sec = rtc_tm_to_time64(tm);
144
145	if (sec > U32_MAX \|\| sec < 0)
146	return -EINVAL;
147
148	writel_relaxed(sec, timer->base + BRCMSTB_WKTMR_COUNTER);
149
150	return 0;
151	}
152
153	static int brcmstb_waketmr_getalarm(struct device *dev,
154	struct rtc_wkalrm *alarm)
155	{
156	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
157	time64_t sec;
158	u32 reg;
159
160	sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_ALARM);
161	if (sec != 0) {
162	/* Alarm is enabled */
163	alarm->enabled = 1;
164	rtc_time64_to_tm(sec, &alarm->time);
165	}
166
167	reg = readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
168	alarm->pending = !!(reg & 1);
169
170	return 0;
171	}
172
173	static int brcmstb_waketmr_setalarm(struct device *dev,
174	struct rtc_wkalrm *alarm)
175	{
176	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
177	time64_t sec;
178
179	if (alarm->enabled)
180	sec = rtc_tm_to_time64(&alarm->time);
181	else
182	sec = 0;
183
184	if (sec > U32_MAX \|\| sec < 0)
185	return -EINVAL;
186
187	brcmstb_waketmr_set_alarm(timer, sec);
188
189	return 0;
190	}
191
192	/*
193	* Does not do much but keep the RTC class happy. We always support
194	* alarms.
195	*/
196	static int brcmstb_waketmr_alarm_enable(struct device *dev,
197	unsigned int enabled)
198	{
199	return 0;
200	}
201
202	static const struct rtc_class_ops brcmstb_waketmr_ops = {
203	.read_time = brcmstb_waketmr_gettime,
204	.set_time = brcmstb_waketmr_settime,
205	.read_alarm = brcmstb_waketmr_getalarm,
206	.set_alarm = brcmstb_waketmr_setalarm,
207	.alarm_irq_enable = brcmstb_waketmr_alarm_enable,
208	};
209
210	static int brcmstb_waketmr_probe(struct platform_device *pdev)
211	{
212	struct device *dev = &pdev->dev;
213	struct brcmstb_waketmr *timer;
214	struct resource *res;
215	int ret;
216
217	timer = devm_kzalloc(dev, sizeof(*timer), GFP_KERNEL);
218	if (!timer)
219	return -ENOMEM;
220
221	platform_set_drvdata(pdev, timer);
222	timer->dev = dev;
223
224	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
225	timer->base = devm_ioremap_resource(dev, res);
226	if (IS_ERR(timer->base))
227	return PTR_ERR(timer->base);
228
229	/*
230	* Set wakeup capability before requesting wakeup interrupt, so we can
231	* process boot-time "wakeups" (e.g., from S5 soft-off)
232	*/
233	device_set_wakeup_capable(dev, true);
234	device_wakeup_enable(dev);
235
236	timer->irq = platform_get_irq(pdev, 0);
237	if (timer->irq < 0)
238	return -ENODEV;
239
240	timer->clk = devm_clk_get(dev, NULL);
241	if (!IS_ERR(timer->clk)) {
242	ret = clk_prepare_enable(timer->clk);
243	if (ret)
244	return ret;
245	timer->rate = clk_get_rate(timer->clk);
246	if (!timer->rate)
247	timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
248	} else {
249	timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
250	timer->clk = NULL;
251	}
252
253	ret = devm_request_irq(dev, timer->irq, brcmstb_waketmr_irq, 0,
254	"brcmstb-waketimer", timer);
255	if (ret < 0)
d6ea1088	256	goto err_clk;
c4f07ece BN	257
	258	timer->reboot_notifier.notifier_call = brcmstb_waketmr_reboot;
	259	register_reboot_notifier(&timer->reboot_notifier);
	260
	261	timer->rtc = rtc_device_register("brcmstb-waketmr", dev,
	262	&brcmstb_waketmr_ops, THIS_MODULE);
	263	if (IS_ERR(timer->rtc)) {
	264	dev_err(dev, "unable to register device\n");
d6ea1088 AK	265	ret = PTR_ERR(timer->rtc);
d6ea1088 AK	266	goto err_notifier;
c4f07ece BN	267	}
	268
	269	dev_info(dev, "registered, with irq %d\n", timer->irq);
	270
d6ea1088 AK	271	return 0;
	272
	273	err_notifier:
	274	unregister_reboot_notifier(&timer->reboot_notifier);
a7b10572	275	clk_disable_unprepare(timer->clk);
d6ea1088 AK	276
	277	err_clk:
	278	if (timer->clk)
	279	clk_disable_unprepare(timer->clk);
	280
c4f07ece BN	281	return ret;
	282	}
	283
	284	static int brcmstb_waketmr_remove(struct platform_device *pdev)
	285	{
	286	struct brcmstb_waketmr *timer = dev_get_drvdata(&pdev->dev);
	287
	288	unregister_reboot_notifier(&timer->reboot_notifier);
	289	rtc_device_unregister(timer->rtc);
	290
	291	return 0;
	292	}
	293
	294	#ifdef CONFIG_PM_SLEEP
	295	static int brcmstb_waketmr_suspend(struct device *dev)
	296	{
	297	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
	298
	299	return brcmstb_waketmr_prepare_suspend(timer);
	300	}
	301
	302	static int brcmstb_waketmr_resume(struct device *dev)
	303	{
	304	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
	305	int ret;
	306
	307	if (!device_may_wakeup(dev))
	308	return 0;
	309
	310	ret = disable_irq_wake(timer->irq);
	311
	312	brcmstb_waketmr_clear_alarm(timer);
	313
	314	return ret;
	315	}
	316	#endif /* CONFIG_PM_SLEEP */
	317
	318	static SIMPLE_DEV_PM_OPS(brcmstb_waketmr_pm_ops,
	319	brcmstb_waketmr_suspend, brcmstb_waketmr_resume);
	320
	321	static const struct of_device_id brcmstb_waketmr_of_match[] = {
	322	{ .compatible = "brcm,brcmstb-waketimer" },
	323	{ /* sentinel */ },
	324	};
	325
	326	static struct platform_driver brcmstb_waketmr_driver = {
	327	.probe = brcmstb_waketmr_probe,
	328	.remove = brcmstb_waketmr_remove,
	329	.driver = {
	330	.name = "brcmstb-waketimer",
	331	.pm = &brcmstb_waketmr_pm_ops,
	332	.of_match_table = of_match_ptr(brcmstb_waketmr_of_match),
	333	}
	334	};
	335	module_platform_driver(brcmstb_waketmr_driver);
	336
	337	MODULE_LICENSE("GPL v2");
	338	MODULE_AUTHOR("Brian Norris");
	339	MODULE_AUTHOR("Markus Mayer");
	340	MODULE_DESCRIPTION("Wake-up timer driver for STB chips");