rtc: add new lp8788 rtc driver (38ae176e) · Commits · 戴 / test

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");

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