[mirror_ubuntu-jammy-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);

	/* Make sure we are actually counting in seconds */
	writel_relaxed(timer->rate, timer->base + BRCMSTB_WKTMR_PRESCALER);

	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);

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
58d3d5e7 JC	63	/* Make sure we are actually counting in seconds */
	64	writel_relaxed(timer->rate, timer->base + BRCMSTB_WKTMR_PRESCALER);
	65
c4f07ece BN	66	writel_relaxed(secs + 1, timer->base + BRCMSTB_WKTMR_ALARM);
	67	}
	68
	69	static irqreturn_t brcmstb_waketmr_irq(int irq, void *data)
	70	{
	71	struct brcmstb_waketmr *timer = data;
	72
	73	pm_wakeup_event(timer->dev, 0);
	74
	75	return IRQ_HANDLED;
	76	}
	77
	78	struct wktmr_time {
	79	u32 sec;
	80	u32 pre;
	81	};
	82
	83	static void wktmr_read(struct brcmstb_waketmr *timer,
	84	struct wktmr_time *t)
	85	{
	86	u32 tmp;
	87
	88	do {
	89	t->sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_COUNTER);
	90	tmp = readl_relaxed(timer->base + BRCMSTB_WKTMR_PRESCALER_VAL);
	91	} while (tmp >= timer->rate);
	92
	93	t->pre = timer->rate - tmp;
	94	}
	95
	96	static int brcmstb_waketmr_prepare_suspend(struct brcmstb_waketmr *timer)
	97	{
	98	struct device *dev = timer->dev;
	99	int ret = 0;
	100
	101	if (device_may_wakeup(dev)) {
	102	ret = enable_irq_wake(timer->irq);
	103	if (ret) {
	104	dev_err(dev, "failed to enable wake-up interrupt\n");
	105	return ret;
	106	}
	107	}
	108
	109	return ret;
	110	}
	111
	112	/* If enabled as a wakeup-source, arm the timer when powering off */
	113	static int brcmstb_waketmr_reboot(struct notifier_block *nb,
	114	unsigned long action, void *data)
	115	{
	116	struct brcmstb_waketmr *timer;
	117
	118	timer = container_of(nb, struct brcmstb_waketmr, reboot_notifier);
	119
	120	/* Set timer for cold boot */
	121	if (action == SYS_POWER_OFF)
	122	brcmstb_waketmr_prepare_suspend(timer);
	123
	124	return NOTIFY_DONE;
	125	}
	126
	127	static int brcmstb_waketmr_gettime(struct device *dev,
	128	struct rtc_time *tm)
	129	{
130	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
131	struct wktmr_time now;
132
133	wktmr_read(timer, &now);
134
135	rtc_time_to_tm(now.sec, tm);
136
137	return 0;
138	}
139
140	static int brcmstb_waketmr_settime(struct device *dev,
141	struct rtc_time *tm)
142	{
143	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
144	time64_t sec;
145
146	sec = rtc_tm_to_time64(tm);
147
148	if (sec > U32_MAX \|\| sec < 0)
149	return -EINVAL;
150
151	writel_relaxed(sec, timer->base + BRCMSTB_WKTMR_COUNTER);
152
153	return 0;
154	}
155
156	static int brcmstb_waketmr_getalarm(struct device *dev,
157	struct rtc_wkalrm *alarm)
158	{
159	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
160	time64_t sec;
161	u32 reg;
162
163	sec = readl_relaxed(timer->base + BRCMSTB_WKTMR_ALARM);
164	if (sec != 0) {
165	/* Alarm is enabled */
166	alarm->enabled = 1;
167	rtc_time64_to_tm(sec, &alarm->time);
168	}
169
170	reg = readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT);
171	alarm->pending = !!(reg & 1);
172
173	return 0;
174	}
175
176	static int brcmstb_waketmr_setalarm(struct device *dev,
177	struct rtc_wkalrm *alarm)
178	{
179	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
180	time64_t sec;
181
182	if (alarm->enabled)
183	sec = rtc_tm_to_time64(&alarm->time);
184	else
185	sec = 0;
186
187	if (sec > U32_MAX \|\| sec < 0)
188	return -EINVAL;
189
190	brcmstb_waketmr_set_alarm(timer, sec);
191
192	return 0;
193	}
194
195	/*
196	* Does not do much but keep the RTC class happy. We always support
197	* alarms.
198	*/
199	static int brcmstb_waketmr_alarm_enable(struct device *dev,
200	unsigned int enabled)
201	{
202	return 0;
203	}
204
205	static const struct rtc_class_ops brcmstb_waketmr_ops = {
206	.read_time = brcmstb_waketmr_gettime,
207	.set_time = brcmstb_waketmr_settime,
208	.read_alarm = brcmstb_waketmr_getalarm,
209	.set_alarm = brcmstb_waketmr_setalarm,
210	.alarm_irq_enable = brcmstb_waketmr_alarm_enable,
211	};
212
213	static int brcmstb_waketmr_probe(struct platform_device *pdev)
214	{
215	struct device *dev = &pdev->dev;
216	struct brcmstb_waketmr *timer;
217	struct resource *res;
218	int ret;
219
220	timer = devm_kzalloc(dev, sizeof(*timer), GFP_KERNEL);
221	if (!timer)
222	return -ENOMEM;
223
224	platform_set_drvdata(pdev, timer);
225	timer->dev = dev;
226
227	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
228	timer->base = devm_ioremap_resource(dev, res);
229	if (IS_ERR(timer->base))
230	return PTR_ERR(timer->base);
231
232	/*
233	* Set wakeup capability before requesting wakeup interrupt, so we can
234	* process boot-time "wakeups" (e.g., from S5 soft-off)
235	*/
236	device_set_wakeup_capable(dev, true);
237	device_wakeup_enable(dev);
238
239	timer->irq = platform_get_irq(pdev, 0);
240	if (timer->irq < 0)
241	return -ENODEV;
242
243	timer->clk = devm_clk_get(dev, NULL);
244	if (!IS_ERR(timer->clk)) {
245	ret = clk_prepare_enable(timer->clk);
246	if (ret)
247	return ret;
248	timer->rate = clk_get_rate(timer->clk);
249	if (!timer->rate)
250	timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
251	} else {
252	timer->rate = BRCMSTB_WKTMR_DEFAULT_FREQ;
253	timer->clk = NULL;
254	}
255
256	ret = devm_request_irq(dev, timer->irq, brcmstb_waketmr_irq, 0,
257	"brcmstb-waketimer", timer);
258	if (ret < 0)
f2eef045	259	goto err_clk;
c4f07ece BN	260
	261	timer->reboot_notifier.notifier_call = brcmstb_waketmr_reboot;
	262	register_reboot_notifier(&timer->reboot_notifier);
	263
	264	timer->rtc = rtc_device_register("brcmstb-waketmr", dev,
	265	&brcmstb_waketmr_ops, THIS_MODULE);
	266	if (IS_ERR(timer->rtc)) {
	267	dev_err(dev, "unable to register device\n");
f2eef045 AK	268	ret = PTR_ERR(timer->rtc);
f2eef045 AK	269	goto err_notifier;
c4f07ece BN	270	}
	271
	272	dev_info(dev, "registered, with irq %d\n", timer->irq);
	273
f2eef045 AK	274	return 0;
	275
	276	err_notifier:
	277	unregister_reboot_notifier(&timer->reboot_notifier);
	278
	279	err_clk:
	280	if (timer->clk)
	281	clk_disable_unprepare(timer->clk);
	282
c4f07ece BN	283	return ret;
	284	}
	285
	286	static int brcmstb_waketmr_remove(struct platform_device *pdev)
	287	{
	288	struct brcmstb_waketmr *timer = dev_get_drvdata(&pdev->dev);
	289
	290	unregister_reboot_notifier(&timer->reboot_notifier);
	291	rtc_device_unregister(timer->rtc);
	292
	293	return 0;
	294	}
	295
	296	#ifdef CONFIG_PM_SLEEP
	297	static int brcmstb_waketmr_suspend(struct device *dev)
	298	{
	299	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
	300
	301	return brcmstb_waketmr_prepare_suspend(timer);
	302	}
	303
	304	static int brcmstb_waketmr_resume(struct device *dev)
	305	{
	306	struct brcmstb_waketmr *timer = dev_get_drvdata(dev);
	307	int ret;
	308
	309	if (!device_may_wakeup(dev))
	310	return 0;
	311
	312	ret = disable_irq_wake(timer->irq);
	313
	314	brcmstb_waketmr_clear_alarm(timer);
	315
	316	return ret;
	317	}
	318	#endif /* CONFIG_PM_SLEEP */
	319
	320	static SIMPLE_DEV_PM_OPS(brcmstb_waketmr_pm_ops,
	321	brcmstb_waketmr_suspend, brcmstb_waketmr_resume);
	322
	323	static const struct of_device_id brcmstb_waketmr_of_match[] = {
	324	{ .compatible = "brcm,brcmstb-waketimer" },
	325	{ /* sentinel */ },
	326	};
	327
	328	static struct platform_driver brcmstb_waketmr_driver = {
	329	.probe = brcmstb_waketmr_probe,
	330	.remove = brcmstb_waketmr_remove,
	331	.driver = {
	332	.name = "brcmstb-waketimer",
	333	.pm = &brcmstb_waketmr_pm_ops,
	334	.of_match_table = of_match_ptr(brcmstb_waketmr_of_match),
	335	}
	336	};
	337	module_platform_driver(brcmstb_waketmr_driver);
	338
	339	MODULE_LICENSE("GPL v2");
	340	MODULE_AUTHOR("Brian Norris");
	341	MODULE_AUTHOR("Markus Mayer");
	342	MODULE_DESCRIPTION("Wake-up timer driver for STB chips");