[linux-2.6-block.git] / drivers / rtc / rtc-wm831x.c

/*
 *	Real Time Clock driver for Wolfson Microelectronics WM831x
 *
 *	Copyright (C) 2009 Wolfson Microelectronics PLC.
 *
 *  Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 *
 *  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/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 int wm831x_rtc_update_irq_enable(struct device *dev,
					unsigned int enabled)
{
	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
	int val;

	if (enabled)
		val = 1 << WM831X_RTC_PINT_FREQ_SHIFT;
	else
		val = 0;

	return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
			       WM831X_RTC_PINT_FREQ_MASK, val);
}

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 irqreturn_t wm831x_per_irq(int irq, void *data)
{
	struct wm831x_rtc *wm831x_rtc = data;

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

	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,
	.update_irq_enable = wm831x_rtc_update_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 per_irq = platform_get_irq_byname(pdev, "PER");
	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 = wm831x_request_irq(wm831x, per_irq, wm831x_per_irq,
				 IRQF_TRIGGER_RISING, "wm831x_rtc_per",
				 wm831x_rtc);
	if (ret != 0) {
		dev_err(&pdev->dev, "Failed to request periodic IRQ %d: %d\n",
			per_irq, ret);
	}

	ret = wm831x_request_irq(wm831x, alm_irq, wm831x_alm_irq,
				 IRQF_TRIGGER_RISING, "wm831x_rtc_alm",
				 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 per_irq = platform_get_irq_byname(pdev, "PER");
	int alm_irq = platform_get_irq_byname(pdev, "ALM");

	wm831x_free_irq(wm831x_rtc->wm831x, alm_irq, wm831x_rtc);
	wm831x_free_irq(wm831x_rtc->wm831x, per_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 <broonie@opensource.wolfsonmicro.com>");
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 <broonie@opensource.wolfsonmicro.com>
	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>
	19	#include <linux/bcd.h>
	20	#include <linux/interrupt.h>
	21	#include <linux/ioctl.h>
	22	#include <linux/completion.h>
	23	#include <linux/mfd/wm831x/core.h>
	24	#include <linux/delay.h>
	25	#include <linux/platform_device.h>
	26
	27
	28	/*
	29	* R16416 (0x4020) - RTC Write Counter
	30	*/
	31	#define WM831X_RTC_WR_CNT_MASK 0xFFFF /* RTC_WR_CNT - [15:0] */
	32	#define WM831X_RTC_WR_CNT_SHIFT 0 /* RTC_WR_CNT - [15:0] */
	33	#define WM831X_RTC_WR_CNT_WIDTH 16 /* RTC_WR_CNT - [15:0] */
	34
	35	/*
	36	* R16417 (0x4021) - RTC Time 1
	37	*/
	38	#define WM831X_RTC_TIME_MASK 0xFFFF /* RTC_TIME - [15:0] */
	39	#define WM831X_RTC_TIME_SHIFT 0 /* RTC_TIME - [15:0] */
	40	#define WM831X_RTC_TIME_WIDTH 16 /* RTC_TIME - [15:0] */
	41
	42	/*
	43	* R16418 (0x4022) - RTC Time 2
	44	*/
	45	#define WM831X_RTC_TIME_MASK 0xFFFF /* RTC_TIME - [15:0] */
	46	#define WM831X_RTC_TIME_SHIFT 0 /* RTC_TIME - [15:0] */
	47	#define WM831X_RTC_TIME_WIDTH 16 /* RTC_TIME - [15:0] */
	48
	49	/*
	50	* R16419 (0x4023) - RTC Alarm 1
	51	*/
	52	#define WM831X_RTC_ALM_MASK 0xFFFF /* RTC_ALM - [15:0] */
	53	#define WM831X_RTC_ALM_SHIFT 0 /* RTC_ALM - [15:0] */
	54	#define WM831X_RTC_ALM_WIDTH 16 /* RTC_ALM - [15:0] */
	55
	56	/*
	57	* R16420 (0x4024) - RTC Alarm 2
	58	*/
	59	#define WM831X_RTC_ALM_MASK 0xFFFF /* RTC_ALM - [15:0] */
	60	#define WM831X_RTC_ALM_SHIFT 0 /* RTC_ALM - [15:0] */
	61	#define WM831X_RTC_ALM_WIDTH 16 /* RTC_ALM - [15:0] */
	62
	63	/*
	64	* R16421 (0x4025) - RTC Control
65	*/
66	#define WM831X_RTC_VALID 0x8000 /* RTC_VALID */
67	#define WM831X_RTC_VALID_MASK 0x8000 /* RTC_VALID */
68	#define WM831X_RTC_VALID_SHIFT 15 /* RTC_VALID */
69	#define WM831X_RTC_VALID_WIDTH 1 /* RTC_VALID */
70	#define WM831X_RTC_SYNC_BUSY 0x4000 /* RTC_SYNC_BUSY */
71	#define WM831X_RTC_SYNC_BUSY_MASK 0x4000 /* RTC_SYNC_BUSY */
72	#define WM831X_RTC_SYNC_BUSY_SHIFT 14 /* RTC_SYNC_BUSY */
73	#define WM831X_RTC_SYNC_BUSY_WIDTH 1 /* RTC_SYNC_BUSY */
74	#define WM831X_RTC_ALM_ENA 0x0400 /* RTC_ALM_ENA */
75	#define WM831X_RTC_ALM_ENA_MASK 0x0400 /* RTC_ALM_ENA */
76	#define WM831X_RTC_ALM_ENA_SHIFT 10 /* RTC_ALM_ENA */
77	#define WM831X_RTC_ALM_ENA_WIDTH 1 /* RTC_ALM_ENA */
78	#define WM831X_RTC_PINT_FREQ_MASK 0x0070 /* RTC_PINT_FREQ - [6:4] */
79	#define WM831X_RTC_PINT_FREQ_SHIFT 4 /* RTC_PINT_FREQ - [6:4] */
80	#define WM831X_RTC_PINT_FREQ_WIDTH 3 /* RTC_PINT_FREQ - [6:4] */
81
82	/*
83	* R16422 (0x4026) - RTC Trim
84	*/
85	#define WM831X_RTC_TRIM_MASK 0x03FF /* RTC_TRIM - [9:0] */
86	#define WM831X_RTC_TRIM_SHIFT 0 /* RTC_TRIM - [9:0] */
87	#define WM831X_RTC_TRIM_WIDTH 10 /* RTC_TRIM - [9:0] */
88
89	#define WM831X_SET_TIME_RETRIES 5
90	#define WM831X_GET_TIME_RETRIES 5
91
92	struct wm831x_rtc {
93	struct wm831x *wm831x;
94	struct rtc_device *rtc;
95	unsigned int alarm_enabled:1;
96	};
97
98	/*
99	* Read current time and date in RTC
100	*/
101	static int wm831x_rtc_readtime(struct device dev, struct rtc_time tm)
102	{
103	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
104	struct wm831x *wm831x = wm831x_rtc->wm831x;
105	u16 time1[2], time2[2];
106	int ret;
107	int count = 0;
108
109	/* Has the RTC been programmed? */
110	ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
111	if (ret < 0) {
112	dev_err(dev, "Failed to read RTC control: %d\n", ret);
113	return ret;
114	}
115	if (!(ret & WM831X_RTC_VALID)) {
116	dev_dbg(dev, "RTC not yet configured\n");
117	return -EINVAL;
118	}
119
120	/* Read twice to make sure we don't read a corrupt, partially
121	* incremented, value.
122	*/
123	do {
124	ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
125	2, time1);
126	if (ret != 0)
127	continue;
128
129	ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
130	2, time2);
131	if (ret != 0)
132	continue;
133
134	if (memcmp(time1, time2, sizeof(time1)) == 0) {
135	u32 time = (time1[0] << 16) \| time1[1];
136
137	rtc_time_to_tm(time, tm);
138	return rtc_valid_tm(tm);
139	}
140
141	} while (++count < WM831X_GET_TIME_RETRIES);
142
143	dev_err(dev, "Timed out reading current time\n");
144
145	return -EIO;
146	}
147
148	/*
149	* Set current time and date in RTC
150	*/
151	static int wm831x_rtc_set_mmss(struct device *dev, unsigned long time)
152	{
153	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
154	struct wm831x *wm831x = wm831x_rtc->wm831x;
155	struct rtc_time new_tm;
156	unsigned long new_time;
157	int ret;
158	int count = 0;
159
160	ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_1,
161	(time >> 16) & 0xffff);
162	if (ret < 0) {
163	dev_err(dev, "Failed to write TIME_1: %d\n", ret);
164	return ret;
165	}
166
167	ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_2, time & 0xffff);
168	if (ret < 0) {
169	dev_err(dev, "Failed to write TIME_2: %d\n", ret);
170	return ret;
171	}
172
173	/* Wait for the update to complete - should happen first time
174	* round but be conservative.
175	*/
176	do {
177	msleep(1);
178
179	ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
180	if (ret < 0)
181	ret = WM831X_RTC_SYNC_BUSY;
182	} while (!(ret & WM831X_RTC_SYNC_BUSY) &&
183	++count < WM831X_SET_TIME_RETRIES);
184
185	if (ret & WM831X_RTC_SYNC_BUSY) {
186	dev_err(dev, "Timed out writing RTC update\n");
187	return -EIO;
188	}
189
190	/* Check that the update was accepted; security features may
191	* have caused the update to be ignored.
192	*/
193	ret = wm831x_rtc_readtime(dev, &new_tm);
194	if (ret < 0)
195	return ret;
196
197	ret = rtc_tm_to_time(&new_tm, &new_time);
198	if (ret < 0) {
199	dev_err(dev, "Failed to convert time: %d\n", ret);
200	return ret;
201	}
202
203	/* Allow a second of change in case of tick */
204	if (new_time - time > 1) {
205	dev_err(dev, "RTC update not permitted by hardware\n");
206	return -EPERM;
207	}
208
209	return 0;
210	}
211
212	/*
213	* Read alarm time and date in RTC
214	*/
215	static int wm831x_rtc_readalarm(struct device dev, struct rtc_wkalrm alrm)
216	{
217	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
218	int ret;
219	u16 data[2];
220	u32 time;
221
222	ret = wm831x_bulk_read(wm831x_rtc->wm831x, WM831X_RTC_ALARM_1,
223	2, data);
224	if (ret != 0) {
225	dev_err(dev, "Failed to read alarm time: %d\n", ret);
226	return ret;
227	}
228
229	time = (data[0] << 16) \| data[1];
230
231	rtc_time_to_tm(time, &alrm->time);
232
233	ret = wm831x_reg_read(wm831x_rtc->wm831x, WM831X_RTC_CONTROL);
234	if (ret < 0) {
235	dev_err(dev, "Failed to read RTC control: %d\n", ret);
236	return ret;
237	}
238
239	if (ret & WM831X_RTC_ALM_ENA)
240	alrm->enabled = 1;
241	else
242	alrm->enabled = 0;
243
244	return 0;
245	}
246
247	static int wm831x_rtc_stop_alarm(struct wm831x_rtc *wm831x_rtc)
248	{
249	wm831x_rtc->alarm_enabled = 0;
250
251	return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
252	WM831X_RTC_ALM_ENA, 0);
253	}
254
255	static int wm831x_rtc_start_alarm(struct wm831x_rtc *wm831x_rtc)
256	{
257	wm831x_rtc->alarm_enabled = 1;
258
259	return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
260	WM831X_RTC_ALM_ENA, WM831X_RTC_ALM_ENA);
261	}
262
263	static int wm831x_rtc_setalarm(struct device dev, struct rtc_wkalrm alrm)
264	{
265	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
266	struct wm831x *wm831x = wm831x_rtc->wm831x;
267	int ret;
268	unsigned long time;
269
270	ret = rtc_tm_to_time(&alrm->time, &time);
271	if (ret < 0) {
272	dev_err(dev, "Failed to convert time: %d\n", ret);
273	return ret;
274	}
275
276	ret = wm831x_rtc_stop_alarm(wm831x_rtc);
277	if (ret < 0) {
278	dev_err(dev, "Failed to stop alarm: %d\n", ret);
279	return ret;
280	}
281
282	ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_1,
283	(time >> 16) & 0xffff);
284	if (ret < 0) {
285	dev_err(dev, "Failed to write ALARM_1: %d\n", ret);
286	return ret;
287	}
288
289	ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_2, time & 0xffff);
290	if (ret < 0) {
291	dev_err(dev, "Failed to write ALARM_2: %d\n", ret);
292	return ret;
293	}
294
295	if (alrm->enabled) {
296	ret = wm831x_rtc_start_alarm(wm831x_rtc);
297	if (ret < 0) {
298	dev_err(dev, "Failed to start alarm: %d\n", ret);
299	return ret;
300	}
301	}
302
303	return 0;
304	}
305
306	static int wm831x_rtc_alarm_irq_enable(struct device *dev,
307	unsigned int enabled)
308	{
309	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
310
311	if (enabled)
312	return wm831x_rtc_start_alarm(wm831x_rtc);
313	else
314	return wm831x_rtc_stop_alarm(wm831x_rtc);
315	}
316
317	static int wm831x_rtc_update_irq_enable(struct device *dev,
318	unsigned int enabled)
319	{
320	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
321	int val;
322
323	if (enabled)
324	val = 1 << WM831X_RTC_PINT_FREQ_SHIFT;
325	else
326	val = 0;
327
328	return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
329	WM831X_RTC_PINT_FREQ_MASK, val);
330	}
331
332	static irqreturn_t wm831x_alm_irq(int irq, void *data)
333	{
334	struct wm831x_rtc *wm831x_rtc = data;
335
336	rtc_update_irq(wm831x_rtc->rtc, 1, RTC_IRQF \| RTC_AF);
337
338	return IRQ_HANDLED;
339	}
340
341	static irqreturn_t wm831x_per_irq(int irq, void *data)
342	{
343	struct wm831x_rtc *wm831x_rtc = data;
344
345	rtc_update_irq(wm831x_rtc->rtc, 1, RTC_IRQF \| RTC_UF);
346
347	return IRQ_HANDLED;
348	}
349
350	static const struct rtc_class_ops wm831x_rtc_ops = {
351	.read_time = wm831x_rtc_readtime,
352	.set_mmss = wm831x_rtc_set_mmss,
353	.read_alarm = wm831x_rtc_readalarm,
354	.set_alarm = wm831x_rtc_setalarm,
355	.alarm_irq_enable = wm831x_rtc_alarm_irq_enable,
356	.update_irq_enable = wm831x_rtc_update_irq_enable,
357	};
358
359	#ifdef CONFIG_PM
360	/* Turn off the alarm if it should not be a wake source. */
361	static int wm831x_rtc_suspend(struct device *dev)
362	{
363	struct platform_device *pdev = to_platform_device(dev);
364	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
365	int ret, enable;
366
367	if (wm831x_rtc->alarm_enabled && device_may_wakeup(&pdev->dev))
368	enable = WM831X_RTC_ALM_ENA;
369	else
370	enable = 0;
371
372	ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
373	WM831X_RTC_ALM_ENA, enable);
374	if (ret != 0)
375	dev_err(&pdev->dev, "Failed to update RTC alarm: %d\n", ret);
376
377	return 0;
378	}
379
380	/* Enable the alarm if it should be enabled (in case it was disabled to
381	* prevent use as a wake source).
382	*/
383	static int wm831x_rtc_resume(struct device *dev)
384	{
385	struct platform_device *pdev = to_platform_device(dev);
386	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
387	int ret;
388
389	if (wm831x_rtc->alarm_enabled) {
390	ret = wm831x_rtc_start_alarm(wm831x_rtc);
391	if (ret != 0)
392	dev_err(&pdev->dev,
393	"Failed to restart RTC alarm: %d\n", ret);
394	}
395
396	return 0;
397	}
398
399	/* Unconditionally disable the alarm */
400	static int wm831x_rtc_freeze(struct device *dev)
401	{
402	struct platform_device *pdev = to_platform_device(dev);
403	struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
404	int ret;
405
406	ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
407	WM831X_RTC_ALM_ENA, 0);
408	if (ret != 0)
409	dev_err(&pdev->dev, "Failed to stop RTC alarm: %d\n", ret);
410
411	return 0;
412	}
413	#else
414	#define wm831x_rtc_suspend NULL
415	#define wm831x_rtc_resume NULL
416	#define wm831x_rtc_freeze NULL
417	#endif
418
419	static int wm831x_rtc_probe(struct platform_device *pdev)
420	{
421	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
422	struct wm831x_rtc *wm831x_rtc;
423	int per_irq = platform_get_irq_byname(pdev, "PER");
424	int alm_irq = platform_get_irq_byname(pdev, "ALM");
425	int ret = 0;
426
427	wm831x_rtc = kzalloc(sizeof(*wm831x_rtc), GFP_KERNEL);
428	if (wm831x_rtc == NULL)
429	return -ENOMEM;
430
431	platform_set_drvdata(pdev, wm831x_rtc);
432	wm831x_rtc->wm831x = wm831x;
433
434	ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
435	if (ret < 0) {
436	dev_err(&pdev->dev, "Failed to read RTC control: %d\n", ret);
437	goto err;
438	}
439	if (ret & WM831X_RTC_ALM_ENA)
440	wm831x_rtc->alarm_enabled = 1;
441
442	device_init_wakeup(&pdev->dev, 1);
443
444	wm831x_rtc->rtc = rtc_device_register("wm831x", &pdev->dev,
445	&wm831x_rtc_ops, THIS_MODULE);
446	if (IS_ERR(wm831x_rtc->rtc)) {
447	ret = PTR_ERR(wm831x_rtc->rtc);
448	goto err;
449	}
450
451	ret = wm831x_request_irq(wm831x, per_irq, wm831x_per_irq,
452	IRQF_TRIGGER_RISING, "wm831x_rtc_per",
453	wm831x_rtc);
454	if (ret != 0) {
455	dev_err(&pdev->dev, "Failed to request periodic IRQ %d: %d\n",
456	per_irq, ret);
457	}
458
459	ret = wm831x_request_irq(wm831x, alm_irq, wm831x_alm_irq,
460	IRQF_TRIGGER_RISING, "wm831x_rtc_alm",
461	wm831x_rtc);
462	if (ret != 0) {
463	dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
464	alm_irq, ret);
465	}
466
467	return 0;
468
469	err:
470	kfree(wm831x_rtc);
471	return ret;
472	}
473
474	static int __devexit wm831x_rtc_remove(struct platform_device *pdev)
475	{
476	struct wm831x_rtc *wm831x_rtc = platform_get_drvdata(pdev);
477	int per_irq = platform_get_irq_byname(pdev, "PER");
478	int alm_irq = platform_get_irq_byname(pdev, "ALM");
479
480	wm831x_free_irq(wm831x_rtc->wm831x, alm_irq, wm831x_rtc);
481	wm831x_free_irq(wm831x_rtc->wm831x, per_irq, wm831x_rtc);
482	rtc_device_unregister(wm831x_rtc->rtc);
483	kfree(wm831x_rtc);
484
485	return 0;
486	}
487
47145210	488	static const struct dev_pm_ops wm831x_rtc_pm_ops = {
35c86bf6 MB	489	.suspend = wm831x_rtc_suspend,
	490	.resume = wm831x_rtc_resume,
	491
	492	.freeze = wm831x_rtc_freeze,
	493	.thaw = wm831x_rtc_resume,
	494	.restore = wm831x_rtc_resume,
	495
	496	.poweroff = wm831x_rtc_suspend,
	497	};
	498
	499	static struct platform_driver wm831x_rtc_driver = {
	500	.probe = wm831x_rtc_probe,
	501	.remove = __devexit_p(wm831x_rtc_remove),
	502	.driver = {
	503	.name = "wm831x-rtc",
	504	.pm = &wm831x_rtc_pm_ops,
	505	},
	506	};
	507
	508	static int __init wm831x_rtc_init(void)
	509	{
	510	return platform_driver_register(&wm831x_rtc_driver);
	511	}
	512	module_init(wm831x_rtc_init);
	513
	514	static void __exit wm831x_rtc_exit(void)
	515	{
	516	platform_driver_unregister(&wm831x_rtc_driver);
	517	}
	518	module_exit(wm831x_rtc_exit);
	519
	520	MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
	521	MODULE_DESCRIPTION("RTC driver for the WM831x series PMICs");
	522	MODULE_LICENSE("GPL");
	523	MODULE_ALIAS("platform:wm831x-rtc");