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Commit 38ae176e authored by Kim, Milo's avatar Kim, Milo Committed by Linus Torvalds
Browse files

rtc: add new lp8788 rtc driver 



TI LP8788 PMU supports regulators, battery charger, RTC, ADC, backlight
driver and current sinks.  This patch enables LP8788 rtc module.

Signed-off-by: default avatarMilo(Woogyom) Kim <milo.kim@ti.com>
Cc: "devendra.aaru" <devendra.aaru@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 56ae1b8e

drivers/rtc/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -204,6 +204,12 @@ config RTC_DRV_DS3232 
	  This driver can also be built as a module.  If so, the module

	  will be called rtc-ds3232.



config RTC_DRV_LP8788

	tristate "TI LP8788 RTC driver"

	depends on MFD_LP8788

	help

	  Say Y to enable support for the LP8788 RTC/ALARM driver.



config RTC_DRV_MAX6900

	tristate "Maxim MAX6900"

	help

drivers/rtc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -57,6 +57,7 @@ obj-$(CONFIG_RTC_DRV_IMXDI) += rtc-imxdi.o 
obj-$(CONFIG_RTC_DRV_ISL1208)	+= rtc-isl1208.o

obj-$(CONFIG_RTC_DRV_ISL12022)	+= rtc-isl12022.o

obj-$(CONFIG_RTC_DRV_JZ4740)	+= rtc-jz4740.o

obj-$(CONFIG_RTC_DRV_LP8788)	+= rtc-lp8788.o

obj-$(CONFIG_RTC_DRV_LPC32XX)	+= rtc-lpc32xx.o

obj-$(CONFIG_RTC_DRV_LOONGSON1)	+= rtc-ls1x.o

obj-$(CONFIG_RTC_DRV_M41T80)	+= rtc-m41t80.o

drivers/rtc/rtc-lp8788.c

0 → 100644
+344 −0
Original line number Diff line number Diff line 
/*

 * TI LP8788 MFD - rtc driver

 *

 * Copyright 2012 Texas Instruments

 *

 * Author: Milo(Woogyom) Kim <milo.kim@ti.com>

 *

 * 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.

 *

 */



#include <linux/err.h>

#include <linux/irqdomain.h>

#include <linux/mfd/lp8788.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/rtc.h>

#include <linux/slab.h>



/* register address */

#define LP8788_INTEN_3			0x05

#define LP8788_RTC_UNLOCK		0x64

#define LP8788_RTC_SEC			0x70

#define LP8788_ALM1_SEC			0x77

#define LP8788_ALM1_EN			0x7D

#define LP8788_ALM2_SEC			0x7E

#define LP8788_ALM2_EN			0x84



/* mask/shift bits */

#define LP8788_INT_RTC_ALM1_M		BIT(1)	/* Addr 05h */

#define LP8788_INT_RTC_ALM1_S		1

#define LP8788_INT_RTC_ALM2_M		BIT(2)	/* Addr 05h */

#define LP8788_INT_RTC_ALM2_S		2

#define LP8788_ALM_EN_M			BIT(7)	/* Addr 7Dh or 84h */

#define LP8788_ALM_EN_S			7



#define DEFAULT_ALARM_SEL		LP8788_ALARM_1

#define LP8788_MONTH_OFFSET		1

#define LP8788_BASE_YEAR		2000

#define MAX_WDAY_BITS			7

#define LP8788_WDAY_SET			1

#define RTC_UNLOCK			0x1

#define RTC_LATCH			0x2

#define ALARM_IRQ_FLAG			(RTC_IRQF | RTC_AF)



enum lp8788_time {

	LPTIME_SEC,

	LPTIME_MIN,

	LPTIME_HOUR,

	LPTIME_MDAY,

	LPTIME_MON,

	LPTIME_YEAR,

	LPTIME_WDAY,

	LPTIME_MAX,

};



struct lp8788_rtc {

	struct lp8788 *lp;

	struct rtc_device *rdev;

	enum lp8788_alarm_sel alarm;

	int irq;

};



static const u8 addr_alarm_sec[LP8788_ALARM_MAX] = {

	LP8788_ALM1_SEC,

	LP8788_ALM2_SEC,

};



static const u8 addr_alarm_en[LP8788_ALARM_MAX] = {

	LP8788_ALM1_EN,

	LP8788_ALM2_EN,

};



static const u8 mask_alarm_en[LP8788_ALARM_MAX] = {

	LP8788_INT_RTC_ALM1_M,

	LP8788_INT_RTC_ALM2_M,

};



static const u8 shift_alarm_en[LP8788_ALARM_MAX] = {

	LP8788_INT_RTC_ALM1_S,

	LP8788_INT_RTC_ALM2_S,

};



static int _to_tm_wday(u8 lp8788_wday)

{

	int i;



	if (lp8788_wday == 0)

		return 0;



	/* lookup defined weekday from read register value */

	for (i = 0; i < MAX_WDAY_BITS; i++) {

		if ((lp8788_wday >> i) == LP8788_WDAY_SET)

			break;

	}



	return i + 1;

}



static inline int _to_lp8788_wday(int tm_wday)

{

	return LP8788_WDAY_SET << (tm_wday - 1);

}



static void lp8788_rtc_unlock(struct lp8788 *lp)

{

	lp8788_write_byte(lp, LP8788_RTC_UNLOCK, RTC_UNLOCK);

	lp8788_write_byte(lp, LP8788_RTC_UNLOCK, RTC_LATCH);

}



static int lp8788_rtc_read_time(struct device *dev, struct rtc_time *tm)

{

	struct lp8788_rtc *rtc = dev_get_drvdata(dev);

	struct lp8788 *lp = rtc->lp;

	u8 data[LPTIME_MAX];

	int ret;



	lp8788_rtc_unlock(lp);



	ret = lp8788_read_multi_bytes(lp, LP8788_RTC_SEC, data,	LPTIME_MAX);

	if (ret)

		return ret;



	tm->tm_sec  = data[LPTIME_SEC];

	tm->tm_min  = data[LPTIME_MIN];

	tm->tm_hour = data[LPTIME_HOUR];

	tm->tm_mday = data[LPTIME_MDAY];

	tm->tm_mon  = data[LPTIME_MON] - LP8788_MONTH_OFFSET;

	tm->tm_year = data[LPTIME_YEAR] + LP8788_BASE_YEAR - 1900;

	tm->tm_wday = _to_tm_wday(data[LPTIME_WDAY]);



	return 0;

}



static int lp8788_rtc_set_time(struct device *dev, struct rtc_time *tm)

{

	struct lp8788_rtc *rtc = dev_get_drvdata(dev);

	struct lp8788 *lp = rtc->lp;

	u8 data[LPTIME_MAX - 1];

	int ret, i, year;



	year = tm->tm_year + 1900 - LP8788_BASE_YEAR;

	if (year < 0) {

		dev_err(lp->dev, "invalid year: %d\n", year);

		return -EINVAL;

	}



	/* because rtc weekday is a readonly register, do not update */

	data[LPTIME_SEC]  = tm->tm_sec;

	data[LPTIME_MIN]  = tm->tm_min;

	data[LPTIME_HOUR] = tm->tm_hour;

	data[LPTIME_MDAY] = tm->tm_mday;

	data[LPTIME_MON]  = tm->tm_mon + LP8788_MONTH_OFFSET;

	data[LPTIME_YEAR] = year;



	for (i = 0; i < ARRAY_SIZE(data); i++) {

		ret = lp8788_write_byte(lp, LP8788_RTC_SEC + i, data[i]);

		if (ret)

			return ret;

	}



	return 0;

}



static int lp8788_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)

{

	struct lp8788_rtc *rtc = dev_get_drvdata(dev);

	struct lp8788 *lp = rtc->lp;

	struct rtc_time *tm = &alarm->time;

	u8 addr, data[LPTIME_MAX];

	int ret;



	addr = addr_alarm_sec[rtc->alarm];

	ret = lp8788_read_multi_bytes(lp, addr, data, LPTIME_MAX);

	if (ret)

		return ret;



	tm->tm_sec  = data[LPTIME_SEC];

	tm->tm_min  = data[LPTIME_MIN];

	tm->tm_hour = data[LPTIME_HOUR];

	tm->tm_mday = data[LPTIME_MDAY];

	tm->tm_mon  = data[LPTIME_MON] - LP8788_MONTH_OFFSET;

	tm->tm_year = data[LPTIME_YEAR] + LP8788_BASE_YEAR - 1900;

	tm->tm_wday = _to_tm_wday(data[LPTIME_WDAY]);

	alarm->enabled = data[LPTIME_WDAY] & LP8788_ALM_EN_M;



	return 0;

}



static int lp8788_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)

{

	struct lp8788_rtc *rtc = dev_get_drvdata(dev);

	struct lp8788 *lp = rtc->lp;

	struct rtc_time *tm = &alarm->time;

	u8 addr, data[LPTIME_MAX];

	int ret, i, year;



	year = tm->tm_year + 1900 - LP8788_BASE_YEAR;

	if (year < 0) {

		dev_err(lp->dev, "invalid year: %d\n", year);

		return -EINVAL;

	}



	data[LPTIME_SEC]  = tm->tm_sec;

	data[LPTIME_MIN]  = tm->tm_min;

	data[LPTIME_HOUR] = tm->tm_hour;

	data[LPTIME_MDAY] = tm->tm_mday;

	data[LPTIME_MON]  = tm->tm_mon + LP8788_MONTH_OFFSET;

	data[LPTIME_YEAR] = year;

	data[LPTIME_WDAY] = _to_lp8788_wday(tm->tm_wday);



	for (i = 0; i < ARRAY_SIZE(data); i++) {

		addr = addr_alarm_sec[rtc->alarm] + i;

		ret = lp8788_write_byte(lp, addr, data[i]);

		if (ret)

			return ret;

	}



	alarm->enabled = 1;

	addr = addr_alarm_en[rtc->alarm];



	return lp8788_update_bits(lp, addr, LP8788_ALM_EN_M,

				alarm->enabled << LP8788_ALM_EN_S);

}



static int lp8788_alarm_irq_enable(struct device *dev, unsigned int enable)

{

	struct lp8788_rtc *rtc = dev_get_drvdata(dev);

	struct lp8788 *lp = rtc->lp;

	u8 mask, shift;



	if (!rtc->irq)

		return -EIO;



	mask = mask_alarm_en[rtc->alarm];

	shift = shift_alarm_en[rtc->alarm];



	return lp8788_update_bits(lp, LP8788_INTEN_3, mask, enable << shift);

}



static const struct rtc_class_ops lp8788_rtc_ops = {

	.read_time = lp8788_rtc_read_time,

	.set_time = lp8788_rtc_set_time,

	.read_alarm = lp8788_read_alarm,

	.set_alarm = lp8788_set_alarm,

	.alarm_irq_enable = lp8788_alarm_irq_enable,

};



static irqreturn_t lp8788_alarm_irq_handler(int irq, void *ptr)

{

	struct lp8788_rtc *rtc = ptr;



	rtc_update_irq(rtc->rdev, 1, ALARM_IRQ_FLAG);

	return IRQ_HANDLED;

}



static int lp8788_alarm_irq_register(struct platform_device *pdev,

				struct lp8788_rtc *rtc)

{

	struct resource *r;

	struct lp8788 *lp = rtc->lp;

	struct irq_domain *irqdm = lp->irqdm;

	int irq;



	rtc->irq = 0;



	/* even the alarm IRQ number is not specified, rtc time should work */

	r = platform_get_resource_byname(pdev, IORESOURCE_IRQ, LP8788_ALM_IRQ);

	if (!r)

		return 0;



	if (rtc->alarm == LP8788_ALARM_1)

		irq = r->start;

	else

		irq = r->end;



	rtc->irq = irq_create_mapping(irqdm, irq);



	return request_threaded_irq(rtc->irq, NULL, lp8788_alarm_irq_handler,

				0, LP8788_ALM_IRQ, rtc);

}



static void lp8788_alarm_irq_unregister(struct lp8788_rtc *rtc)

{

	if (rtc->irq)

		free_irq(rtc->irq, rtc);

}



static int lp8788_rtc_probe(struct platform_device *pdev)

{

	struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);

	struct lp8788_rtc *rtc;

	struct device *dev = &pdev->dev;



	rtc = devm_kzalloc(dev, sizeof(struct lp8788_rtc), GFP_KERNEL);

	if (!rtc)

		return -ENOMEM;



	rtc->lp = lp;

	rtc->alarm = lp->pdata ? lp->pdata->alarm_sel : DEFAULT_ALARM_SEL;

	platform_set_drvdata(pdev, rtc);



	device_init_wakeup(dev, 1);



	rtc->rdev = rtc_device_register("lp8788_rtc", dev,

					&lp8788_rtc_ops, THIS_MODULE);

	if (IS_ERR(rtc->rdev)) {

		dev_err(dev, "can not register rtc device\n");

		return PTR_ERR(rtc->rdev);

	}



	if (lp8788_alarm_irq_register(pdev, rtc))

		dev_warn(lp->dev, "no rtc irq handler\n");



	return 0;

}



static int lp8788_rtc_remove(struct platform_device *pdev)

{

	struct lp8788_rtc *rtc = platform_get_drvdata(pdev);



	lp8788_alarm_irq_unregister(rtc);

	rtc_device_unregister(rtc->rdev);

	platform_set_drvdata(pdev, NULL);



	return 0;

}



static struct platform_driver lp8788_rtc_driver = {

	.probe = lp8788_rtc_probe,

	.remove = lp8788_rtc_remove,

	.driver = {

		.name = LP8788_DEV_RTC,

		.owner = THIS_MODULE,

	},

};

module_platform_driver(lp8788_rtc_driver);



MODULE_DESCRIPTION("Texas Instruments LP8788 RTC Driver");

MODULE_AUTHOR("Milo Kim");

MODULE_LICENSE("GPL");

MODULE_ALIAS("platform:lp8788-rtc");