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rtc: Add MAX8998 rtc driver
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This adds support for the RTC provided by the Maxim 8998 chip. This
driver was tested on a GONI board by using the rtc-test application from
the Documentation/rtc.txt.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
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Joonyoung Shim authored and Samuel Ortiz committed Oct 28, 2010
1 parent 2c7e6f5 commit 9b16c0a
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Showing 5 changed files with 339 additions and 2 deletions.
24 changes: 23 additions & 1 deletion drivers/mfd/max8998.c
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Expand Up @@ -30,10 +30,14 @@
#include <linux/mfd/max8998.h>
#include <linux/mfd/max8998-private.h>

#define RTC_I2C_ADDR (0x0c >> 1)

static struct mfd_cell max8998_devs[] = {
{
.name = "max8998-pmic",
}
}, {
.name = "max8998-rtc",
},
};

int max8998_read_reg(struct i2c_client *i2c, u8 reg, u8 *dest)
Expand Down Expand Up @@ -80,6 +84,21 @@ int max8998_write_reg(struct i2c_client *i2c, u8 reg, u8 value)
}
EXPORT_SYMBOL(max8998_write_reg);

int max8998_bulk_write(struct i2c_client *i2c, u8 reg, int count, u8 *buf)
{
struct max8998_dev *max8998 = i2c_get_clientdata(i2c);
int ret;

mutex_lock(&max8998->iolock);
ret = i2c_smbus_write_i2c_block_data(i2c, reg, count, buf);
mutex_unlock(&max8998->iolock);
if (ret < 0)
return ret;

return 0;
}
EXPORT_SYMBOL(max8998_bulk_write);

int max8998_update_reg(struct i2c_client *i2c, u8 reg, u8 val, u8 mask)
{
struct max8998_dev *max8998 = i2c_get_clientdata(i2c);
Expand Down Expand Up @@ -120,6 +139,9 @@ static int max8998_i2c_probe(struct i2c_client *i2c,
}
mutex_init(&max8998->iolock);

max8998->rtc = i2c_new_dummy(i2c->adapter, RTC_I2C_ADDR);
i2c_set_clientdata(max8998->rtc, max8998);

max8998_irq_init(max8998);

ret = mfd_add_devices(max8998->dev, -1,
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10 changes: 10 additions & 0 deletions drivers/rtc/Kconfig
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Expand Up @@ -196,6 +196,16 @@ config RTC_DRV_MAX8925
This driver can also be built as a module. If so, the module
will be called rtc-max8925.

config RTC_DRV_MAX8998
tristate "Maxim MAX8998"
depends on MFD_MAX8998
help
If you say yes here you will get support for the
RTC of Maxim MAX8998 PMIC.

This driver can also be built as a module. If so, the module
will be called rtc-max8998.

config RTC_DRV_RS5C372
tristate "Ricoh R2025S/D, RS5C372A/B, RV5C386, RV5C387A"
help
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1 change: 1 addition & 0 deletions drivers/rtc/Makefile
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Expand Up @@ -60,6 +60,7 @@ obj-$(CONFIG_RTC_DRV_M48T86) += rtc-m48t86.o
obj-$(CONFIG_RTC_MXC) += rtc-mxc.o
obj-$(CONFIG_RTC_DRV_MAX6900) += rtc-max6900.o
obj-$(CONFIG_RTC_DRV_MAX8925) += rtc-max8925.o
obj-$(CONFIG_RTC_DRV_MAX8998) += rtc-max8998.o
obj-$(CONFIG_RTC_DRV_MAX6902) += rtc-max6902.o
obj-$(CONFIG_RTC_DRV_MC13783) += rtc-mc13783.o
obj-$(CONFIG_RTC_DRV_MSM6242) += rtc-msm6242.o
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300 changes: 300 additions & 0 deletions drivers/rtc/rtc-max8998.c
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@@ -0,0 +1,300 @@
/*
* RTC driver for Maxim MAX8998
*
* Copyright (C) 2010 Samsung Electronics Co.Ltd
* Author: Minkyu Kang <mk7.kang@samsung.com>
* Author: Joonyoung Shim <jy0922.shim@samsung.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/i2c.h>
#include <linux/slab.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/mfd/max8998.h>
#include <linux/mfd/max8998-private.h>

#define MAX8998_RTC_SEC 0x00
#define MAX8998_RTC_MIN 0x01
#define MAX8998_RTC_HOUR 0x02
#define MAX8998_RTC_WEEKDAY 0x03
#define MAX8998_RTC_DATE 0x04
#define MAX8998_RTC_MONTH 0x05
#define MAX8998_RTC_YEAR1 0x06
#define MAX8998_RTC_YEAR2 0x07
#define MAX8998_ALARM0_SEC 0x08
#define MAX8998_ALARM0_MIN 0x09
#define MAX8998_ALARM0_HOUR 0x0a
#define MAX8998_ALARM0_WEEKDAY 0x0b
#define MAX8998_ALARM0_DATE 0x0c
#define MAX8998_ALARM0_MONTH 0x0d
#define MAX8998_ALARM0_YEAR1 0x0e
#define MAX8998_ALARM0_YEAR2 0x0f
#define MAX8998_ALARM1_SEC 0x10
#define MAX8998_ALARM1_MIN 0x11
#define MAX8998_ALARM1_HOUR 0x12
#define MAX8998_ALARM1_WEEKDAY 0x13
#define MAX8998_ALARM1_DATE 0x14
#define MAX8998_ALARM1_MONTH 0x15
#define MAX8998_ALARM1_YEAR1 0x16
#define MAX8998_ALARM1_YEAR2 0x17
#define MAX8998_ALARM0_CONF 0x18
#define MAX8998_ALARM1_CONF 0x19
#define MAX8998_RTC_STATUS 0x1a
#define MAX8998_WTSR_SMPL_CNTL 0x1b
#define MAX8998_TEST 0x1f

#define HOUR_12 (1 << 7)
#define HOUR_PM (1 << 5)
#define ALARM0_STATUS (1 << 1)
#define ALARM1_STATUS (1 << 2)

enum {
RTC_SEC = 0,
RTC_MIN,
RTC_HOUR,
RTC_WEEKDAY,
RTC_DATE,
RTC_MONTH,
RTC_YEAR1,
RTC_YEAR2,
};

struct max8998_rtc_info {
struct device *dev;
struct max8998_dev *max8998;
struct i2c_client *rtc;
struct rtc_device *rtc_dev;
int irq;
};

static void max8998_data_to_tm(u8 *data, struct rtc_time *tm)
{
tm->tm_sec = bcd2bin(data[RTC_SEC]);
tm->tm_min = bcd2bin(data[RTC_MIN]);
if (data[RTC_HOUR] & HOUR_12) {
tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x1f);
if (data[RTC_HOUR] & HOUR_PM)
tm->tm_hour += 12;
} else
tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f);

tm->tm_wday = data[RTC_WEEKDAY] & 0x07;
tm->tm_mday = bcd2bin(data[RTC_DATE]);
tm->tm_mon = bcd2bin(data[RTC_MONTH]);
tm->tm_year = bcd2bin(data[RTC_YEAR1]) + bcd2bin(data[RTC_YEAR2]) * 100;
tm->tm_year -= 1900;
}

static void max8998_tm_to_data(struct rtc_time *tm, u8 *data)
{
data[RTC_SEC] = bin2bcd(tm->tm_sec);
data[RTC_MIN] = bin2bcd(tm->tm_min);
data[RTC_HOUR] = bin2bcd(tm->tm_hour);
data[RTC_WEEKDAY] = tm->tm_wday;
data[RTC_DATE] = bin2bcd(tm->tm_mday);
data[RTC_MONTH] = bin2bcd(tm->tm_mon);
data[RTC_YEAR1] = bin2bcd(tm->tm_year % 100);
data[RTC_YEAR2] = bin2bcd((tm->tm_year + 1900) / 100);
}

static int max8998_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct max8998_rtc_info *info = dev_get_drvdata(dev);
u8 data[8];
int ret;

ret = max8998_bulk_read(info->rtc, MAX8998_RTC_SEC, 8, data);
if (ret < 0)
return ret;

max8998_data_to_tm(data, tm);

return rtc_valid_tm(tm);
}

static int max8998_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct max8998_rtc_info *info = dev_get_drvdata(dev);
u8 data[8];

max8998_tm_to_data(tm, data);

return max8998_bulk_write(info->rtc, MAX8998_RTC_SEC, 8, data);
}

static int max8998_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct max8998_rtc_info *info = dev_get_drvdata(dev);
u8 data[8];
u8 val;
int ret;

ret = max8998_bulk_read(info->rtc, MAX8998_ALARM0_SEC, 8, data);
if (ret < 0)
return ret;

max8998_data_to_tm(data, &alrm->time);

ret = max8998_read_reg(info->rtc, MAX8998_ALARM0_CONF, &val);
if (ret < 0)
return ret;

alrm->enabled = !!val;

ret = max8998_read_reg(info->rtc, MAX8998_RTC_STATUS, &val);
if (ret < 0)
return ret;

if (val & ALARM0_STATUS)
alrm->pending = 1;
else
alrm->pending = 0;

return 0;
}

static int max8998_rtc_stop_alarm(struct max8998_rtc_info *info)
{
return max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, 0);
}

static int max8998_rtc_start_alarm(struct max8998_rtc_info *info)
{
return max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, 0x77);
}

static int max8998_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct max8998_rtc_info *info = dev_get_drvdata(dev);
u8 data[8];
int ret;

max8998_tm_to_data(&alrm->time, data);

ret = max8998_rtc_stop_alarm(info);
if (ret < 0)
return ret;

ret = max8998_bulk_write(info->rtc, MAX8998_ALARM0_SEC, 8, data);
if (ret < 0)
return ret;

if (alrm->enabled)
return max8998_rtc_start_alarm(info);

return 0;
}

static int max8998_rtc_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct max8998_rtc_info *info = dev_get_drvdata(dev);

if (enabled)
return max8998_rtc_start_alarm(info);
else
return max8998_rtc_stop_alarm(info);
}

static irqreturn_t max8998_rtc_alarm_irq(int irq, void *data)
{
struct max8998_rtc_info *info = data;

rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);

return IRQ_HANDLED;
}

static const struct rtc_class_ops max8998_rtc_ops = {
.read_time = max8998_rtc_read_time,
.set_time = max8998_rtc_set_time,
.read_alarm = max8998_rtc_read_alarm,
.set_alarm = max8998_rtc_set_alarm,
.alarm_irq_enable = max8998_rtc_alarm_irq_enable,
};

static int __devinit max8998_rtc_probe(struct platform_device *pdev)
{
struct max8998_dev *max8998 = dev_get_drvdata(pdev->dev.parent);
struct max8998_rtc_info *info;
int ret;

info = kzalloc(sizeof(struct max8998_rtc_info), GFP_KERNEL);
if (!info)
return -ENOMEM;

info->dev = &pdev->dev;
info->max8998 = max8998;
info->rtc = max8998->rtc;
info->irq = max8998->irq_base + MAX8998_IRQ_ALARM0;

info->rtc_dev = rtc_device_register("max8998-rtc", &pdev->dev,
&max8998_rtc_ops, THIS_MODULE);

if (IS_ERR(info->rtc_dev)) {
ret = PTR_ERR(info->rtc_dev);
dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
goto out_rtc;
}

platform_set_drvdata(pdev, info);

ret = request_threaded_irq(info->irq, NULL, max8998_rtc_alarm_irq, 0,
"rtc-alarm0", info);
if (ret < 0)
dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
info->irq, ret);

return 0;

out_rtc:
kfree(info);
return ret;
}

static int __devexit max8998_rtc_remove(struct platform_device *pdev)
{
struct max8998_rtc_info *info = platform_get_drvdata(pdev);

if (info) {
free_irq(info->irq, info);
rtc_device_unregister(info->rtc_dev);
kfree(info);
}

return 0;
}

static struct platform_driver max8998_rtc_driver = {
.driver = {
.name = "max8998-rtc",
.owner = THIS_MODULE,
},
.probe = max8998_rtc_probe,
.remove = __devexit_p(max8998_rtc_remove),
};

static int __init max8998_rtc_init(void)
{
return platform_driver_register(&max8998_rtc_driver);
}
module_init(max8998_rtc_init);

static void __exit max8998_rtc_exit(void)
{
platform_driver_unregister(&max8998_rtc_driver);
}
module_exit(max8998_rtc_exit);

MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
MODULE_DESCRIPTION("Maxim MAX8998 RTC driver");
MODULE_LICENSE("GPL");
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