rtc: add Intersil ISL12022 RTC driver (d6c7428f) · Commits · e / devices / android_kernel_sony_msm8994

drivers/rtc/Kconfig

+9 −0

Original line number	Diff line number	Diff line
		@@ -203,6 +203,15 @@ config RTC_DRV_ISL1208
		This driver can also be built as a module. If so, the module
		will be called rtc-isl1208.

		config RTC_DRV_ISL12022
		tristate "Intersil ISL12022"
		help
		If you say yes here you get support for the
		Intersil ISL12022 RTC chip.

		This driver can also be built as a module. If so, the module
		will be called rtc-isl12022.

		config RTC_DRV_X1205
		tristate "Xicor/Intersil X1205"
		help

drivers/rtc/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -48,6 +48,7 @@ obj-$(CONFIG_RTC_DRV_FM3130) += rtc-fm3130.o
		obj-$(CONFIG_RTC_DRV_GENERIC) += rtc-generic.o
		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-$(CONFIG_RTC_DRV_M41T80) += rtc-m41t80.o
		obj-$(CONFIG_RTC_DRV_M41T94) += rtc-m41t94.o

drivers/rtc/rtc-isl12022.c

0 → 100644

+327 −0

Original line number	Diff line number	Diff line
		/*
		* An I2C driver for the Intersil ISL 12022
		*
		* Author: Roman Fietze <roman.fietze@telemotive.de>
		*
		* Based on the Philips PCF8563 RTC
		* by Alessandro Zummo <a.zummo@towertech.it>.
		*
		* 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/i2c.h>
		#include <linux/bcd.h>
		#include <linux/rtc.h>
		#include <linux/slab.h>

		#define DRV_VERSION "0.1"

		/* ISL register offsets */
		#define ISL12022_REG_SC 0x00
		#define ISL12022_REG_MN 0x01
		#define ISL12022_REG_HR 0x02
		#define ISL12022_REG_DT 0x03
		#define ISL12022_REG_MO 0x04
		#define ISL12022_REG_YR 0x05
		#define ISL12022_REG_DW 0x06

		#define ISL12022_REG_SR 0x07
		#define ISL12022_REG_INT 0x08

		/* ISL register bits */
		#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */

		#define ISL12022_SR_LBAT85 (1 << 2)
		#define ISL12022_SR_LBAT75 (1 << 1)

		#define ISL12022_INT_WRTC (1 << 6)


		static struct i2c_driver isl12022_driver;

		struct isl12022 {
		struct rtc_device *rtc;

		bool write_enabled; /* true if write enable is set */
		};


		static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
		uint8_t *data, size_t n)
		{
		struct i2c_msg msgs[] = {
		{
		.addr = client->addr,
		.flags = 0,
		.len = 1,
		.buf = data
		}, /* setup read ptr */
		{
		.addr = client->addr,
		.flags = I2C_M_RD,
		.len = n,
		.buf = data
		}
		};

		int ret;

		data[0] = reg;
		ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
		if (ret != ARRAY_SIZE(msgs)) {
		dev_err(&client->dev, "%s: read error, ret=%d\n",
		__func__, ret);
		return -EIO;
		}

		return 0;
		}


		static int isl12022_write_reg(struct i2c_client *client,
		uint8_t reg, uint8_t val)
		{
		uint8_t data[2] = { reg, val };
		int err;

		err = i2c_master_send(client, data, sizeof(data));
		if (err != sizeof(data)) {
		dev_err(&client->dev,
		"%s: err=%d addr=%02x, data=%02x\n",
		__func__, err, data[0], data[1]);
		return -EIO;
		}

		return 0;
		}


		/*
		* In the routines that deal directly with the isl12022 hardware, we use
		* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
		*/
		static int isl12022_get_datetime(struct i2c_client client, struct rtc_time tm)
		{
		uint8_t buf[ISL12022_REG_INT + 1];
		int ret;

		ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
		if (ret)
		return ret;

		if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 \| ISL12022_SR_LBAT75)) {
		dev_warn(&client->dev,
		"voltage dropped below %u%%, "
		"date and time is not reliable.\n",
		buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
		}

		dev_dbg(&client->dev,
		"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
		"mday=%02x, mon=%02x, year=%02x, wday=%02x, "
		"sr=%02x, int=%02x",
		__func__,
		buf[ISL12022_REG_SC],
		buf[ISL12022_REG_MN],
		buf[ISL12022_REG_HR],
		buf[ISL12022_REG_DT],
		buf[ISL12022_REG_MO],
		buf[ISL12022_REG_YR],
		buf[ISL12022_REG_DW],
		buf[ISL12022_REG_SR],
		buf[ISL12022_REG_INT]);

		tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
		tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
		tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
		tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
		tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
		tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
		tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;

		dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
		"mday=%d, mon=%d, year=%d, wday=%d\n",
		__func__,
		tm->tm_sec, tm->tm_min, tm->tm_hour,
		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

		/* The clock can give out invalid datetime, but we cannot return
		* -EINVAL otherwise hwclock will refuse to set the time on bootup. */
		if (rtc_valid_tm(tm) < 0)
		dev_err(&client->dev, "retrieved date and time is invalid.\n");

		return 0;
		}

		static int isl12022_set_datetime(struct i2c_client client, struct rtc_time tm)
		{
		struct isl12022 *isl12022 = i2c_get_clientdata(client);
		size_t i;
		int ret;
		uint8_t buf[ISL12022_REG_DW + 1];

		dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
		"mday=%d, mon=%d, year=%d, wday=%d\n",
		__func__,
		tm->tm_sec, tm->tm_min, tm->tm_hour,
		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

		if (!isl12022->write_enabled) {

		ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
		if (ret)
		return ret;

		/* Check if WRTC (write rtc enable) is set factory default is
		* 0 (not set) */
		if (!(buf[0] & ISL12022_INT_WRTC)) {
		dev_info(&client->dev,
		"init write enable and 24 hour format\n");

		/* Set the write enable bit. */
		ret = isl12022_write_reg(client,
		ISL12022_REG_INT,
		buf[0] \| ISL12022_INT_WRTC);
		if (ret)
		return ret;

		/* Write to any RTC register to start RTC, we use the
		* HR register, setting the MIL bit to use the 24 hour
		* format. */
		ret = isl12022_read_regs(client, ISL12022_REG_HR,
		buf, 1);
		if (ret)
		return ret;

		ret = isl12022_write_reg(client,
		ISL12022_REG_HR,
		buf[0] \| ISL12022_HR_MIL);
		if (ret)
		return ret;
		}

		isl12022->write_enabled = 1;
		}

		/* hours, minutes and seconds */
		buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
		buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
		buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour);

		buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);

		/* month, 1 - 12 */
		buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);

		/* year and century */
		buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);

		buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;

		/* write register's data */
		for (i = 0; i < ARRAY_SIZE(buf); i++) {
		ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
		buf[ISL12022_REG_SC + i]);
		if (ret)
		return -EIO;
		};

		return 0;
		}

		static int isl12022_rtc_read_time(struct device dev, struct rtc_time tm)
		{
		return isl12022_get_datetime(to_i2c_client(dev), tm);
		}

		static int isl12022_rtc_set_time(struct device dev, struct rtc_time tm)
		{
		return isl12022_set_datetime(to_i2c_client(dev), tm);
		}

		static const struct rtc_class_ops isl12022_rtc_ops = {
		.read_time = isl12022_rtc_read_time,
		.set_time = isl12022_rtc_set_time,
		};

		static int isl12022_probe(struct i2c_client *client,
		const struct i2c_device_id *id)
		{
		struct isl12022 *isl12022;

		int ret = 0;

		if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
		return -ENODEV;

		isl12022 = kzalloc(sizeof(struct isl12022), GFP_KERNEL);
		if (!isl12022)
		return -ENOMEM;

		dev_dbg(&client->dev, "chip found, driver version " DRV_VERSION "\n");

		i2c_set_clientdata(client, isl12022);

		isl12022->rtc = rtc_device_register(isl12022_driver.driver.name,
		&client->dev,
		&isl12022_rtc_ops,
		THIS_MODULE);

		if (IS_ERR(isl12022->rtc)) {
		ret = PTR_ERR(isl12022->rtc);
		goto exit_kfree;
		}

		return 0;

		exit_kfree:
		kfree(isl12022);

		return ret;
		}

		static int isl12022_remove(struct i2c_client *client)
		{
		struct isl12022 *isl12022 = i2c_get_clientdata(client);

		rtc_device_unregister(isl12022->rtc);
		kfree(isl12022);

		return 0;
		}

		static const struct i2c_device_id isl12022_id[] = {
		{ "isl12022", 0 },
		{ "rtc8564", 0 },
		{ }
		};
		MODULE_DEVICE_TABLE(i2c, isl12022_id);

		static struct i2c_driver isl12022_driver = {
		.driver = {
		.name = "rtc-isl12022",
		},
		.probe = isl12022_probe,
		.remove = isl12022_remove,
		.id_table = isl12022_id,
		};

		static int __init isl12022_init(void)
		{
		return i2c_add_driver(&isl12022_driver);
		}

		static void __exit isl12022_exit(void)
		{
		i2c_del_driver(&isl12022_driver);
		}

		module_init(isl12022_init);
		module_exit(isl12022_exit);

		MODULE_AUTHOR("roman.fietze@telemotive.de");
		MODULE_DESCRIPTION("ISL 12022 RTC driver");
		MODULE_LICENSE("GPL");
		MODULE_VERSION(DRV_VERSION);