[linux.git] / drivers / rtc / rtc-wm831x.c

/*
 *	Real Time Clock driver for Wolfson Microelectronics WM831x
 *
 *	Copyright (C) 2009 Wolfson Microelectronics PLC.
 *
 *  Author: Mark Brown <[email protected]>
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <linux/bcd.h>
#include <linux/interrupt.h>
#include <linux/ioctl.h>
#include <linux/completion.h>
#include <linux/mfd/wm831x/core.h>
#include <linux/delay.h>
#include <linux/platform_device.h>


/*
 * R16416 (0x4020) - RTC Write Counter
 */
#define WM831X_RTC_WR_CNT_MASK                  0xFFFF  /* RTC_WR_CNT - [15:0] */
#define WM831X_RTC_WR_CNT_SHIFT                      0  /* RTC_WR_CNT - [15:0] */
#define WM831X_RTC_WR_CNT_WIDTH                     16  /* RTC_WR_CNT - [15:0] */

/*
 * R16417 (0x4021) - RTC Time 1
 */
#define WM831X_RTC_TIME_MASK                    0xFFFF  /* RTC_TIME - [15:0] */
#define WM831X_RTC_TIME_SHIFT                        0  /* RTC_TIME - [15:0] */
#define WM831X_RTC_TIME_WIDTH                       16  /* RTC_TIME - [15:0] */

/*
 * R16418 (0x4022) - RTC Time 2
 */
#define WM831X_RTC_TIME_MASK                    0xFFFF  /* RTC_TIME - [15:0] */
#define WM831X_RTC_TIME_SHIFT                        0  /* RTC_TIME - [15:0] */
#define WM831X_RTC_TIME_WIDTH                       16  /* RTC_TIME - [15:0] */

/*
 * R16419 (0x4023) - RTC Alarm 1
 */
#define WM831X_RTC_ALM_MASK                     0xFFFF  /* RTC_ALM - [15:0] */
#define WM831X_RTC_ALM_SHIFT                         0  /* RTC_ALM - [15:0] */
#define WM831X_RTC_ALM_WIDTH                        16  /* RTC_ALM - [15:0] */

/*
 * R16420 (0x4024) - RTC Alarm 2
 */
#define WM831X_RTC_ALM_MASK                     0xFFFF  /* RTC_ALM - [15:0] */
#define WM831X_RTC_ALM_SHIFT                         0  /* RTC_ALM - [15:0] */
#define WM831X_RTC_ALM_WIDTH                        16  /* RTC_ALM - [15:0] */

/*
 * R16421 (0x4025) - RTC Control
 */
#define WM831X_RTC_VALID                        0x8000  /* RTC_VALID */
#define WM831X_RTC_VALID_MASK                   0x8000  /* RTC_VALID */
#define WM831X_RTC_VALID_SHIFT                      15  /* RTC_VALID */
#define WM831X_RTC_VALID_WIDTH                       1  /* RTC_VALID */
#define WM831X_RTC_SYNC_BUSY                    0x4000  /* RTC_SYNC_BUSY */
#define WM831X_RTC_SYNC_BUSY_MASK               0x4000  /* RTC_SYNC_BUSY */
#define WM831X_RTC_SYNC_BUSY_SHIFT                  14  /* RTC_SYNC_BUSY */
#define WM831X_RTC_SYNC_BUSY_WIDTH                   1  /* RTC_SYNC_BUSY */
#define WM831X_RTC_ALM_ENA                      0x0400  /* RTC_ALM_ENA */
#define WM831X_RTC_ALM_ENA_MASK                 0x0400  /* RTC_ALM_ENA */
#define WM831X_RTC_ALM_ENA_SHIFT                    10  /* RTC_ALM_ENA */
#define WM831X_RTC_ALM_ENA_WIDTH                     1  /* RTC_ALM_ENA */
#define WM831X_RTC_PINT_FREQ_MASK               0x0070  /* RTC_PINT_FREQ - [6:4] */
#define WM831X_RTC_PINT_FREQ_SHIFT                   4  /* RTC_PINT_FREQ - [6:4] */
#define WM831X_RTC_PINT_FREQ_WIDTH                   3  /* RTC_PINT_FREQ - [6:4] */

/*
 * R16422 (0x4026) - RTC Trim
 */
#define WM831X_RTC_TRIM_MASK                    0x03FF  /* RTC_TRIM - [9:0] */
#define WM831X_RTC_TRIM_SHIFT                        0  /* RTC_TRIM - [9:0] */
#define WM831X_RTC_TRIM_WIDTH                       10  /* RTC_TRIM - [9:0] */

#define WM831X_SET_TIME_RETRIES	5
#define WM831X_GET_TIME_RETRIES	5

struct wm831x_rtc {
	struct wm831x *wm831x;
	struct rtc_device *rtc;
	unsigned int alarm_enabled:1;
};

/*
 * Read current time and date in RTC
 */
static int wm831x_rtc_readtime(struct device *dev, struct rtc_time *tm)
{
	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
	struct wm831x *wm831x = wm831x_rtc->wm831x;
	u16 time1[2], time2[2];
	int ret;
	int count = 0;

	/* Has the RTC been programmed? */
	ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
	if (ret < 0) {
		dev_err(dev, "Failed to read RTC control: %d\n", ret);
		return ret;
	}
	if (!(ret & WM831X_RTC_VALID)) {
		dev_dbg(dev, "RTC not yet configured\n");
		return -EINVAL;
	}

	/* Read twice to make sure we don't read a corrupt, partially
	 * incremented, value.
	 */
	do {
		ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
				       2, time1);
		if (ret != 0)
			continue;

		ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
				       2, time2);
		if (ret != 0)
			continue;

		if (memcmp(time1, time2, sizeof(time1)) == 0) {
			u32 time = (time1[0] << 16) | time1[1];

			rtc_time_to_tm(time, tm);
			return rtc_valid_tm(tm);
		}

	} while (++count < WM831X_GET_TIME_RETRIES);

	dev_err(dev, "Timed out reading current time\n");

	return -EIO;
}

/*
 * Set current time and date in RTC
 */
static int wm831x_rtc_set_mmss(struct device *dev, unsigned long time)
{
	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
	struct wm831x *wm831x = wm831x_rtc->wm831x;
	struct rtc_time new_tm;
	unsigned long new_time;
	int ret;
	int count = 0;

	ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_1,
			       (time >> 16) & 0xffff);
	if (ret < 0) {
		dev_err(dev, "Failed to write TIME_1: %d\n", ret);
		return ret;
	}

	ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_2, time & 0xffff);
	if (ret < 0) {
		dev_err(dev, "Failed to write TIME_2: %d\n", ret);
		return ret;
	}

	/* Wait for the update to complete - should happen first time
	 * round but be conservative.
	 */
	do {
		msleep(1);

		ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
		if (ret < 0)
			ret = WM831X_RTC_SYNC_BUSY;
	} while (!(ret & WM831X_RTC_SYNC_BUSY) &&
		 ++count < WM831X_SET_TIME_RETRIES);

	if (ret & WM831X_RTC_SYNC_BUSY) {
		dev_err(dev, "Timed out writing RTC update\n");
		return -EIO;
	}

	/* Check that the update was accepted; security features may
	 * have caused the update to be ignored.
	 */
	ret = wm831x_rtc_readtime(dev, &new_tm);
	if (ret < 0)
		return ret;

	ret = rtc_tm_to_time(&new_tm, &new_time);
	if (ret < 0) {
		dev_err(dev, "Failed to convert time: %d\n", ret);
		return ret;
	}

	/* Allow a second of change in case of tick */
	if (new_time - time > 1) {
		dev_err(dev, "RTC update not permitted by hardware\n");
		return -EPERM;
	}

	return 0;
}

/*
 * Read alarm time and date in RTC
 */
static int wm831x_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
	int ret;
	u16 data[2];
	u32 time;

	ret = wm831x_bulk_read(wm831x_rtc->wm831x, WM831X_RTC_ALARM_1,
			       2, data);
	if (ret != 0) {
		dev_err(dev, "Failed to read alarm time: %d\n", ret);
		return ret;
	}

	time = (data[0] << 16) | data[1];

	rtc_time_to_tm(time, &alrm->time);

	ret = wm831x_reg_read(wm831x_rtc->wm831x, WM831X_RTC_CONTROL);
	if (ret < 0) {
		dev_err(dev, "Failed to read RTC control: %d\n", ret);
		return ret;
	}

	if (ret & WM831X_RTC_ALM_ENA)
		alrm->enabled = 1;
	else
		alrm->enabled = 0;

	return 0;
}

static int wm831x_rtc_stop_alarm(struct wm831x_rtc *wm831x_rtc)
{
	wm831x_rtc->alarm_enabled = 0;

	return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
			       WM831X_RTC_ALM_ENA, 0);
}

static int wm831x_rtc_start_alarm(struct wm831x_rtc *wm831x_rtc)
{
	wm831x_rtc->alarm_enabled = 1;

	return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
			       WM831X_RTC_ALM_ENA, WM831X_RTC_ALM_ENA);
}

static int wm831x_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
	struct wm831x *wm831x = wm831x_rtc->wm831x;
	int ret;
	unsigned long time;

	ret = rtc_tm_to_time(&alrm->time, &time);
	if (ret < 0) {
		dev_err(dev, "Failed to convert time: %d\n", ret);
		return ret;
	}

	ret = wm831x_rtc_stop_alarm(wm831x_rtc);
	if (ret < 0) {
		dev_err(dev, "Failed to stop alarm: %d\n", ret);
		return ret;
	}

	ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_1,
			       (time >> 16) & 0xffff);
	if (ret < 0) {
		dev_err(dev, "Failed to write ALARM_1: %d\n", ret);
		return ret;
	}

	ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_2, time & 0xffff);
	if (ret < 0) {
		dev_err(dev, "Failed to write ALARM_2: %d\n", ret);
		return ret;
	}

	if (alrm->enabled) {
		ret = wm831x_rtc_start_alarm(wm831x_rtc);
		if (ret < 0) {
			dev_err(dev, "Failed to start alarm: %d\n", ret);
			return ret;
		}
	}

	return 0;
}

static int wm831x_rtc_alarm_irq_enable(struct device *dev,
				       unsigned int enabled)
{
	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);

	if (enabled)
		return wm831x_rtc_start_alarm(wm831x_rtc);
	else
		return wm831x_rtc_stop_alarm(wm831x_rtc);
}

static irqreturn_t wm831x_alm_irq(int irq, void *data)
{
	struct wm831x_rtc *wm831x_rtc = data;

	rtc_update_irq(wm831x_rtc->rtc, 1, RTC_IRQF | RTC_AF);

	return IRQ_HANDLED;
}

static const struct rtc_class_ops wm831x_rtc_ops = {
	.read_time = wm831x_rtc_readtime,
	.set_mmss = wm831x_rtc_set_mmss,
	.read_alarm = wm831x_rtc_readalarm,
	.set_alarm = wm831x_rtc_setalarm,
	.alarm_irq_enable = wm831x_rtc_alarm_irq_enable,
};

#ifdef CONFIG_PM
/* Turn off the alarm if it should not be a wake source. */
static int wm831x_rtc_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
	int ret, enable;

	if (wm831x_rtc->alarm_enabled && device_may_wakeup(&pdev->dev))
		enable = WM831X_RTC_ALM_ENA;
	else
		enable = 0;

	ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
			      WM831X_RTC_ALM_ENA, enable);
	if (ret != 0)
		dev_err(&pdev->dev, "Failed to update RTC alarm: %d\n", ret);

	return 0;
}

/* Enable the alarm if it should be enabled (in case it was disabled to
 * prevent use as a wake source).
 */
static int wm831x_rtc_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
	int ret;

	if (wm831x_rtc->alarm_enabled) {
		ret = wm831x_rtc_start_alarm(wm831x_rtc);
		if (ret != 0)
			dev_err(&pdev->dev,
				"Failed to restart RTC alarm: %d\n", ret);
	}

	return 0;
}

/* Unconditionally disable the alarm */
static int wm831x_rtc_freeze(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
	int ret;

	ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
			      WM831X_RTC_ALM_ENA, 0);
	if (ret != 0)
		dev_err(&pdev->dev, "Failed to stop RTC alarm: %d\n", ret);

	return 0;
}
#else
#define wm831x_rtc_suspend NULL
#define wm831x_rtc_resume NULL
#define wm831x_rtc_freeze NULL
#endif

static int wm831x_rtc_probe(struct platform_device *pdev)
{
	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
	struct wm831x_rtc *wm831x_rtc;
	int alm_irq = platform_get_irq_byname(pdev, "ALM");
	int ret = 0;

	wm831x_rtc = kzalloc(sizeof(*wm831x_rtc), GFP_KERNEL);
	if (wm831x_rtc == NULL)
		return -ENOMEM;

	platform_set_drvdata(pdev, wm831x_rtc);
	wm831x_rtc->wm831x = wm831x;

	ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
	if (ret < 0) {
		dev_err(&pdev->dev, "Failed to read RTC control: %d\n", ret);
		goto err;
	}
	if (ret & WM831X_RTC_ALM_ENA)
		wm831x_rtc->alarm_enabled = 1;

	device_init_wakeup(&pdev->dev, 1);

	wm831x_rtc->rtc = rtc_device_register("wm831x", &pdev->dev,
					      &wm831x_rtc_ops, THIS_MODULE);
	if (IS_ERR(wm831x_rtc->rtc)) {
		ret = PTR_ERR(wm831x_rtc->rtc);
		goto err;
	}

	ret = request_threaded_irq(alm_irq, NULL, wm831x_alm_irq,
				   IRQF_TRIGGER_RISING, "RTC alarm",
				   wm831x_rtc);
	if (ret != 0) {
		dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
			alm_irq, ret);
	}

	return 0;

err:
	kfree(wm831x_rtc);
	return ret;
}

static int __devexit wm831x_rtc_remove(struct platform_device *pdev)
{
	struct wm831x_rtc *wm831x_rtc = platform_get_drvdata(pdev);
	int alm_irq = platform_get_irq_byname(pdev, "ALM");

	free_irq(alm_irq, wm831x_rtc);
	rtc_device_unregister(wm831x_rtc->rtc);
	kfree(wm831x_rtc);

	return 0;
}

static const struct dev_pm_ops wm831x_rtc_pm_ops = {
	.suspend = wm831x_rtc_suspend,
	.resume = wm831x_rtc_resume,

	.freeze = wm831x_rtc_freeze,
	.thaw = wm831x_rtc_resume,
	.restore = wm831x_rtc_resume,

	.poweroff = wm831x_rtc_suspend,
};

static struct platform_driver wm831x_rtc_driver = {
	.probe = wm831x_rtc_probe,
	.remove = __devexit_p(wm831x_rtc_remove),
	.driver = {
		.name = "wm831x-rtc",
		.pm = &wm831x_rtc_pm_ops,
	},
};

static int __init wm831x_rtc_init(void)
{
	return platform_driver_register(&wm831x_rtc_driver);
}
module_init(wm831x_rtc_init);

static void __exit wm831x_rtc_exit(void)
{
	platform_driver_unregister(&wm831x_rtc_driver);
}
module_exit(wm831x_rtc_exit);

MODULE_AUTHOR("Mark Brown <[email protected]>");
MODULE_DESCRIPTION("RTC driver for the WM831x series PMICs");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-rtc");
Commit	Line	Data
35c86bf6 MB	1	/*
	2	* Real Time Clock driver for Wolfson Microelectronics WM831x
	3	*
	4	* Copyright (C) 2009 Wolfson Microelectronics PLC.
	5	*
	6	* Author: Mark Brown <[email protected]>
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License as published by the
	10	* Free Software Foundation; either version 2 of the License, or (at your
	11	* option) any later version.
	12	*
	13	*/
	14
	15	#include <linux/module.h>
	16	#include <linux/kernel.h>
	17	#include <linux/time.h>
	18	#include <linux/rtc.h>
5a0e3ad6	19	#include <linux/slab.h>
35c86bf6 MB	20	#include <linux/bcd.h>
	21	#include <linux/interrupt.h>
	22	#include <linux/ioctl.h>
	23	#include <linux/completion.h>
	24	#include <linux/mfd/wm831x/core.h>
	25	#include <linux/delay.h>
	26	#include <linux/platform_device.h>
	27
	28
	29	/*
	30	* R16416 (0x4020) - RTC Write Counter
	31	*/
	32	#define WM831X_RTC_WR_CNT_MASK 0xFFFF /* RTC_WR_CNT - [15:0] */
	33	#define WM831X_RTC_WR_CNT_SHIFT 0 /* RTC_WR_CNT - [15:0] */
	34	#define WM831X_RTC_WR_CNT_WIDTH 16 /* RTC_WR_CNT - [15:0] */
	35
	36	/*
	37	* R16417 (0x4021) - RTC Time 1
	38	*/
	39	#define WM831X_RTC_TIME_MASK 0xFFFF /* RTC_TIME - [15:0] */
	40	#define WM831X_RTC_TIME_SHIFT 0 /* RTC_TIME - [15:0] */
	41	#define WM831X_RTC_TIME_WIDTH 16 /* RTC_TIME - [15:0] */
	42
	43	/*
	44	* R16418 (0x4022) - RTC Time 2
	45	*/
	46	#define WM831X_RTC_TIME_MASK 0xFFFF /* RTC_TIME - [15:0] */
	47	#define WM831X_RTC_TIME_SHIFT 0 /* RTC_TIME - [15:0] */
	48	#define WM831X_RTC_TIME_WIDTH 16 /* RTC_TIME - [15:0] */
	49
	50	/*
	51	* R16419 (0x4023) - RTC Alarm 1
	52	*/
	53	#define WM831X_RTC_ALM_MASK 0xFFFF /* RTC_ALM - [15:0] */
	54	#define WM831X_RTC_ALM_SHIFT 0 /* RTC_ALM - [15:0] */
	55	#define WM831X_RTC_ALM_WIDTH 16 /* RTC_ALM - [15:0] */
	56
	57	/*
	58	* R16420 (0x4024) - RTC Alarm 2
	59	*/
	60	#define WM831X_RTC_ALM_MASK 0xFFFF /* RTC_ALM - [15:0] */
	61	#define WM831X_RTC_ALM_SHIFT 0 /* RTC_ALM - [15:0] */
	62	#define WM831X_RTC_ALM_WIDTH 16 /* RTC_ALM - [15:0] */
	63
	64	/*
	65	* R16421 (0x4025) - RTC Control
	66	*/
	67	#define WM831X_RTC_VALID 0x8000 /* RTC_VALID */
	68	#define WM831X_RTC_VALID_MASK 0x8000 /* RTC_VALID */
	69	#define WM831X_RTC_VALID_SHIFT 15 /* RTC_VALID */
	70	#define WM831X_RTC_VALID_WIDTH 1 /* RTC_VALID */
	71	#define WM831X_RTC_SYNC_BUSY 0x4000 /* RTC_SYNC_BUSY */
	72	#define WM831X_RTC_SYNC_BUSY_MASK 0x4000 /* RTC_SYNC_BUSY */
	73	#define WM831X_RTC_SYNC_BUSY_SHIFT 14 /* RTC_SYNC_BUSY */
	74	#define WM831X_RTC_SYNC_BUSY_WIDTH 1 /* RTC_SYNC_BUSY */
	75	#define WM831X_RTC_ALM_ENA 0x0400 /* RTC_ALM_ENA */
	76	#define WM831X_RTC_ALM_ENA_MASK 0x0400 /* RTC_ALM_ENA */
	77	#define WM831X_RTC_ALM_ENA_SHIFT 10 /* RTC_ALM_ENA */
	78	#define WM831X_RTC_ALM_ENA_WIDTH 1 /* RTC_ALM_ENA */
	79	#define WM831X_RTC_PINT_FREQ_MASK 0x0070 /* RTC_PINT_FREQ - [6:4] */
	80	#define WM831X_RTC_PINT_FREQ_SHIFT 4 /* RTC_PINT_FREQ - [6:4] */
	81	#define WM831X_RTC_PINT_FREQ_WIDTH 3 /* RTC_PINT_FREQ - [6:4] */
	82
	83	/*
84	* R16422 (0x4026) - RTC Trim
85	*/
86	#define WM831X_RTC_TRIM_MASK 0x03FF /* RTC_TRIM - [9:0] */
87	#define WM831X_RTC_TRIM_SHIFT 0 /* RTC_TRIM - [9:0] */
88	#define WM831X_RTC_TRIM_WIDTH 10 /* RTC_TRIM - [9:0] */
89
90	#define WM831X_SET_TIME_RETRIES 5
91	#define WM831X_GET_TIME_RETRIES 5
92
93	struct wm831x_rtc {
94	struct wm831x *wm831x;
95	struct rtc_device *rtc;
96	unsigned int alarm_enabled:1;
97	};
98
99	/*
100	* Read current time and date in RTC
101	*/
102	static int wm831x_rtc_readtime(struct device dev, struct rtc_time tm)
103	{
104	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
105	struct wm831x *wm831x = wm831x_rtc->wm831x;
106	u16 time1[2], time2[2];
107	int ret;
108	int count = 0;
109
110	/* Has the RTC been programmed? */
111	ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
112	if (ret < 0) {
113	dev_err(dev, "Failed to read RTC control: %d\n", ret);
114	return ret;
115	}
116	if (!(ret & WM831X_RTC_VALID)) {
117	dev_dbg(dev, "RTC not yet configured\n");
118	return -EINVAL;
119	}
120
121	/* Read twice to make sure we don't read a corrupt, partially
122	* incremented, value.
123	*/
124	do {
125	ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
126	2, time1);
127	if (ret != 0)
128	continue;
129
130	ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
131	2, time2);
132	if (ret != 0)
133	continue;
134
135	if (memcmp(time1, time2, sizeof(time1)) == 0) {
136	u32 time = (time1[0] << 16) \| time1[1];
137
138	rtc_time_to_tm(time, tm);
139	return rtc_valid_tm(tm);
140	}
141
142	} while (++count < WM831X_GET_TIME_RETRIES);
143
144	dev_err(dev, "Timed out reading current time\n");
145
146	return -EIO;
147	}
148
149	/*
150	* Set current time and date in RTC
151	*/
152	static int wm831x_rtc_set_mmss(struct device *dev, unsigned long time)
153	{
154	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
155	struct wm831x *wm831x = wm831x_rtc->wm831x;
156	struct rtc_time new_tm;
157	unsigned long new_time;
158	int ret;
159	int count = 0;
160
161	ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_1,
162	(time >> 16) & 0xffff);
163	if (ret < 0) {
164	dev_err(dev, "Failed to write TIME_1: %d\n", ret);
165	return ret;
166	}
167
168	ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_2, time & 0xffff);
169	if (ret < 0) {
170	dev_err(dev, "Failed to write TIME_2: %d\n", ret);
171	return ret;
172	}
173
174	/* Wait for the update to complete - should happen first time
175	* round but be conservative.
176	*/
177	do {
178	msleep(1);
179
180	ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
181	if (ret < 0)
182	ret = WM831X_RTC_SYNC_BUSY;
183	} while (!(ret & WM831X_RTC_SYNC_BUSY) &&
184	++count < WM831X_SET_TIME_RETRIES);
185
186	if (ret & WM831X_RTC_SYNC_BUSY) {
187	dev_err(dev, "Timed out writing RTC update\n");
188	return -EIO;
189	}
190
191	/* Check that the update was accepted; security features may
192	* have caused the update to be ignored.
193	*/
194	ret = wm831x_rtc_readtime(dev, &new_tm);
195	if (ret < 0)
196	return ret;
197
198	ret = rtc_tm_to_time(&new_tm, &new_time);
199	if (ret < 0) {
200	dev_err(dev, "Failed to convert time: %d\n", ret);
201	return ret;
202	}
203
204	/* Allow a second of change in case of tick */
205	if (new_time - time > 1) {
206	dev_err(dev, "RTC update not permitted by hardware\n");
207	return -EPERM;
208	}
209
210	return 0;
211	}
212
213	/*
214	* Read alarm time and date in RTC
215	*/
216	static int wm831x_rtc_readalarm(struct device dev, struct rtc_wkalrm alrm)
217	{
218	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
219	int ret;
220	u16 data[2];
221	u32 time;
222
223	ret = wm831x_bulk_read(wm831x_rtc->wm831x, WM831X_RTC_ALARM_1,
224	2, data);
225	if (ret != 0) {
226	dev_err(dev, "Failed to read alarm time: %d\n", ret);
227	return ret;
228	}
229
230	time = (data[0] << 16) \| data[1];
231
232	rtc_time_to_tm(time, &alrm->time);
233
234	ret = wm831x_reg_read(wm831x_rtc->wm831x, WM831X_RTC_CONTROL);
235	if (ret < 0) {
236	dev_err(dev, "Failed to read RTC control: %d\n", ret);
237	return ret;
238	}
239
240	if (ret & WM831X_RTC_ALM_ENA)
241	alrm->enabled = 1;
242	else
243	alrm->enabled = 0;
244
245	return 0;
246	}
247
248	static int wm831x_rtc_stop_alarm(struct wm831x_rtc *wm831x_rtc)
249	{
250	wm831x_rtc->alarm_enabled = 0;
251
252	return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
253	WM831X_RTC_ALM_ENA, 0);
254	}
255
256	static int wm831x_rtc_start_alarm(struct wm831x_rtc *wm831x_rtc)
257	{
258	wm831x_rtc->alarm_enabled = 1;
259
260	return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
261	WM831X_RTC_ALM_ENA, WM831X_RTC_ALM_ENA);
262	}
263
264	static int wm831x_rtc_setalarm(struct device dev, struct rtc_wkalrm alrm)
265	{
266	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
267	struct wm831x *wm831x = wm831x_rtc->wm831x;
268	int ret;
269	unsigned long time;
270
271	ret = rtc_tm_to_time(&alrm->time, &time);
272	if (ret < 0) {
273	dev_err(dev, "Failed to convert time: %d\n", ret);
274	return ret;
275	}
276
277	ret = wm831x_rtc_stop_alarm(wm831x_rtc);
278	if (ret < 0) {
279	dev_err(dev, "Failed to stop alarm: %d\n", ret);
280	return ret;
281	}
282
283	ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_1,
284	(time >> 16) & 0xffff);
285	if (ret < 0) {
286	dev_err(dev, "Failed to write ALARM_1: %d\n", ret);
287	return ret;
288	}
289
290	ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_2, time & 0xffff);
291	if (ret < 0) {
292	dev_err(dev, "Failed to write ALARM_2: %d\n", ret);
293	return ret;
294	}
295
296	if (alrm->enabled) {
297	ret = wm831x_rtc_start_alarm(wm831x_rtc);
298	if (ret < 0) {
299	dev_err(dev, "Failed to start alarm: %d\n", ret);
300	return ret;
301	}
302	}
303
304	return 0;
305	}
306
307	static int wm831x_rtc_alarm_irq_enable(struct device *dev,
308	unsigned int enabled)
309	{
310	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
311
312	if (enabled)
313	return wm831x_rtc_start_alarm(wm831x_rtc);
314	else
315	return wm831x_rtc_stop_alarm(wm831x_rtc);
316	}
317
35c86bf6 MB	318	static irqreturn_t wm831x_alm_irq(int irq, void *data)
	319	{
	320	struct wm831x_rtc *wm831x_rtc = data;
	321
	322	rtc_update_irq(wm831x_rtc->rtc, 1, RTC_IRQF \| RTC_AF);
	323
	324	return IRQ_HANDLED;
	325	}
	326
35c86bf6 MB	327	static const struct rtc_class_ops wm831x_rtc_ops = {
	328	.read_time = wm831x_rtc_readtime,
	329	.set_mmss = wm831x_rtc_set_mmss,
	330	.read_alarm = wm831x_rtc_readalarm,
	331	.set_alarm = wm831x_rtc_setalarm,
	332	.alarm_irq_enable = wm831x_rtc_alarm_irq_enable,
35c86bf6 MB	333	};
	334
	335	#ifdef CONFIG_PM
	336	/* Turn off the alarm if it should not be a wake source. */
	337	static int wm831x_rtc_suspend(struct device *dev)
	338	{
	339	struct platform_device *pdev = to_platform_device(dev);
	340	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
	341	int ret, enable;
	342
	343	if (wm831x_rtc->alarm_enabled && device_may_wakeup(&pdev->dev))
	344	enable = WM831X_RTC_ALM_ENA;
	345	else
	346	enable = 0;
	347
	348	ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
	349	WM831X_RTC_ALM_ENA, enable);
	350	if (ret != 0)
	351	dev_err(&pdev->dev, "Failed to update RTC alarm: %d\n", ret);
	352
	353	return 0;
	354	}
	355
	356	/* Enable the alarm if it should be enabled (in case it was disabled to
	357	* prevent use as a wake source).
	358	*/
	359	static int wm831x_rtc_resume(struct device *dev)
	360	{
	361	struct platform_device *pdev = to_platform_device(dev);
	362	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
	363	int ret;
	364
	365	if (wm831x_rtc->alarm_enabled) {
	366	ret = wm831x_rtc_start_alarm(wm831x_rtc);
	367	if (ret != 0)
	368	dev_err(&pdev->dev,
	369	"Failed to restart RTC alarm: %d\n", ret);
	370	}
	371
	372	return 0;
	373	}
	374
	375	/* Unconditionally disable the alarm */
	376	static int wm831x_rtc_freeze(struct device *dev)
	377	{
	378	struct platform_device *pdev = to_platform_device(dev);
	379	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
	380	int ret;
	381
	382	ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
	383	WM831X_RTC_ALM_ENA, 0);
	384	if (ret != 0)
	385	dev_err(&pdev->dev, "Failed to stop RTC alarm: %d\n", ret);
	386
	387	return 0;
	388	}
	389	#else
	390	#define wm831x_rtc_suspend NULL
	391	#define wm831x_rtc_resume NULL
	392	#define wm831x_rtc_freeze NULL
	393	#endif
	394
	395	static int wm831x_rtc_probe(struct platform_device *pdev)
	396	{
397	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
398	struct wm831x_rtc *wm831x_rtc;
35c86bf6 MB	399	int alm_irq = platform_get_irq_byname(pdev, "ALM");
	400	int ret = 0;
	401
	402	wm831x_rtc = kzalloc(sizeof(*wm831x_rtc), GFP_KERNEL);
	403	if (wm831x_rtc == NULL)
	404	return -ENOMEM;
	405
	406	platform_set_drvdata(pdev, wm831x_rtc);
	407	wm831x_rtc->wm831x = wm831x;
	408
	409	ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
	410	if (ret < 0) {
	411	dev_err(&pdev->dev, "Failed to read RTC control: %d\n", ret);
	412	goto err;
	413	}
	414	if (ret & WM831X_RTC_ALM_ENA)
	415	wm831x_rtc->alarm_enabled = 1;
	416
	417	device_init_wakeup(&pdev->dev, 1);
	418
	419	wm831x_rtc->rtc = rtc_device_register("wm831x", &pdev->dev,
	420	&wm831x_rtc_ops, THIS_MODULE);
	421	if (IS_ERR(wm831x_rtc->rtc)) {
	422	ret = PTR_ERR(wm831x_rtc->rtc);
	423	goto err;
	424	}
	425
5815e5d3 MB	426	ret = request_threaded_irq(alm_irq, NULL, wm831x_alm_irq,
	427	IRQF_TRIGGER_RISING, "RTC alarm",
	428	wm831x_rtc);
35c86bf6 MB	429	if (ret != 0) {
	430	dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
	431	alm_irq, ret);
	432	}
	433
	434	return 0;
	435
	436	err:
	437	kfree(wm831x_rtc);
	438	return ret;
	439	}
	440
	441	static int __devexit wm831x_rtc_remove(struct platform_device *pdev)
	442	{
	443	struct wm831x_rtc *wm831x_rtc = platform_get_drvdata(pdev);
35c86bf6 MB	444	int alm_irq = platform_get_irq_byname(pdev, "ALM");
35c86bf6 MB	445
5815e5d3	446	free_irq(alm_irq, wm831x_rtc);
35c86bf6 MB	447	rtc_device_unregister(wm831x_rtc->rtc);
	448	kfree(wm831x_rtc);
	449
	450	return 0;
	451	}
	452
47145210	453	static const struct dev_pm_ops wm831x_rtc_pm_ops = {
35c86bf6 MB	454	.suspend = wm831x_rtc_suspend,
	455	.resume = wm831x_rtc_resume,
	456
	457	.freeze = wm831x_rtc_freeze,
	458	.thaw = wm831x_rtc_resume,
	459	.restore = wm831x_rtc_resume,
	460
	461	.poweroff = wm831x_rtc_suspend,
	462	};
	463
	464	static struct platform_driver wm831x_rtc_driver = {
	465	.probe = wm831x_rtc_probe,
	466	.remove = __devexit_p(wm831x_rtc_remove),
	467	.driver = {
	468	.name = "wm831x-rtc",
	469	.pm = &wm831x_rtc_pm_ops,
	470	},
	471	};
	472
	473	static int __init wm831x_rtc_init(void)
	474	{
	475	return platform_driver_register(&wm831x_rtc_driver);
	476	}
	477	module_init(wm831x_rtc_init);
	478
	479	static void __exit wm831x_rtc_exit(void)
	480	{
	481	platform_driver_unregister(&wm831x_rtc_driver);
	482	}
	483	module_exit(wm831x_rtc_exit);
	484
	485	MODULE_AUTHOR("Mark Brown <[email protected]>");
	486	MODULE_DESCRIPTION("RTC driver for the WM831x series PMICs");
	487	MODULE_LICENSE("GPL");
	488	MODULE_ALIAS("platform:wm831x-rtc");