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Star64_linux/drivers/rtc/rtc-max77686.c
Javier Martinez Canillas 90a5698a86 rtc: max77686: Add an indirection level to access RTC registers 
The max77686 driver is generic enough that can be used for other
Maxim RTC IP blocks but these might not have the same registers
layout so instead of accessing the registers directly, add a map
to translate offsets to the real registers addresses for each IP.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-02-04 23:42:08 +01:00

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/*
* RTC driver for Maxim MAX77686
*
* Copyright (C) 2012 Samsung Electronics Co.Ltd
*
* based on rtc-max8997.c
*
* 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.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/slab.h>
#include <linux/rtc.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/mfd/max77686-private.h>
#include <linux/irqdomain.h>
#include <linux/regmap.h>
/* RTC Control Register */
#define BCD_EN_SHIFT 0
#define BCD_EN_MASK (1 << BCD_EN_SHIFT)
#define MODEL24_SHIFT 1
#define MODEL24_MASK (1 << MODEL24_SHIFT)
/* RTC Update Register1 */
#define RTC_UDR_SHIFT 0
#define RTC_UDR_MASK (1 << RTC_UDR_SHIFT)
#define RTC_RBUDR_SHIFT 4
#define RTC_RBUDR_MASK (1 << RTC_RBUDR_SHIFT)
/* RTC Hour register */
#define HOUR_PM_SHIFT 6
#define HOUR_PM_MASK (1 << HOUR_PM_SHIFT)
/* RTC Alarm Enable */
#define ALARM_ENABLE_SHIFT 7
#define ALARM_ENABLE_MASK (1 << ALARM_ENABLE_SHIFT)
enum {
RTC_SEC = 0,
RTC_MIN,
RTC_HOUR,
RTC_WEEKDAY,
RTC_MONTH,
RTC_YEAR,
RTC_DATE,
RTC_NR_TIME
};
struct max77686_rtc_driver_data {
/* Minimum usecs needed for a RTC update */
unsigned long delay;
/* Mask used to read RTC registers value */
u8 mask;
/* Registers offset to I2C addresses map */
const unsigned int *map;
};
struct max77686_rtc_info {
struct device *dev;
struct max77686_dev *max77686;
struct i2c_client *rtc;
struct rtc_device *rtc_dev;
struct mutex lock;
struct regmap *regmap;
const struct max77686_rtc_driver_data *drv_data;
int virq;
int rtc_24hr_mode;
};
enum MAX77686_RTC_OP {
MAX77686_RTC_WRITE,
MAX77686_RTC_READ,
};
/* These are not registers but just offsets that are mapped to addresses */
enum max77686_rtc_reg_offset {
REG_RTC_CONTROLM = 0,
REG_RTC_CONTROL,
REG_RTC_UPDATE0,
REG_WTSR_SMPL_CNTL,
REG_RTC_SEC,
REG_RTC_MIN,
REG_RTC_HOUR,
REG_RTC_WEEKDAY,
REG_RTC_MONTH,
REG_RTC_YEAR,
REG_RTC_DATE,
REG_ALARM1_SEC,
REG_ALARM1_MIN,
REG_ALARM1_HOUR,
REG_ALARM1_WEEKDAY,
REG_ALARM1_MONTH,
REG_ALARM1_YEAR,
REG_ALARM1_DATE,
REG_ALARM2_SEC,
REG_ALARM2_MIN,
REG_ALARM2_HOUR,
REG_ALARM2_WEEKDAY,
REG_ALARM2_MONTH,
REG_ALARM2_YEAR,
REG_ALARM2_DATE,
REG_RTC_END,
};
/* Maps RTC registers offset to the MAX77686 register addresses */
static const unsigned int max77686_map[REG_RTC_END] = {
[REG_RTC_CONTROLM] = MAX77686_RTC_CONTROLM,
[REG_RTC_CONTROL] = MAX77686_RTC_CONTROL,
[REG_RTC_UPDATE0] = MAX77686_RTC_UPDATE0,
[REG_WTSR_SMPL_CNTL] = MAX77686_WTSR_SMPL_CNTL,
[REG_RTC_SEC] = MAX77686_RTC_SEC,
[REG_RTC_MIN] = MAX77686_RTC_MIN,
[REG_RTC_HOUR] = MAX77686_RTC_HOUR,
[REG_RTC_WEEKDAY] = MAX77686_RTC_WEEKDAY,
[REG_RTC_MONTH] = MAX77686_RTC_MONTH,
[REG_RTC_YEAR] = MAX77686_RTC_YEAR,
[REG_RTC_DATE] = MAX77686_RTC_DATE,
[REG_ALARM1_SEC] = MAX77686_ALARM1_SEC,
[REG_ALARM1_MIN] = MAX77686_ALARM1_MIN,
[REG_ALARM1_HOUR] = MAX77686_ALARM1_HOUR,
[REG_ALARM1_WEEKDAY] = MAX77686_ALARM1_WEEKDAY,
[REG_ALARM1_MONTH] = MAX77686_ALARM1_MONTH,
[REG_ALARM1_YEAR] = MAX77686_ALARM1_YEAR,
[REG_ALARM1_DATE] = MAX77686_ALARM1_DATE,
[REG_ALARM2_SEC] = MAX77686_ALARM2_SEC,
[REG_ALARM2_MIN] = MAX77686_ALARM2_MIN,
[REG_ALARM2_HOUR] = MAX77686_ALARM2_HOUR,
[REG_ALARM2_WEEKDAY] = MAX77686_ALARM2_WEEKDAY,
[REG_ALARM2_MONTH] = MAX77686_ALARM2_MONTH,
[REG_ALARM2_YEAR] = MAX77686_ALARM2_YEAR,
[REG_ALARM2_DATE] = MAX77686_ALARM2_DATE,
};
static const struct max77686_rtc_driver_data max77686_drv_data = {
.delay = 16000,
.mask = 0x7f,
.map = max77686_map,
};
static void max77686_rtc_data_to_tm(u8 *data, struct rtc_time *tm,
struct max77686_rtc_info *info)
{
u8 mask = info->drv_data->mask;
tm->tm_sec = data[RTC_SEC] & mask;
tm->tm_min = data[RTC_MIN] & mask;
if (info->rtc_24hr_mode)
tm->tm_hour = data[RTC_HOUR] & 0x1f;
else {
tm->tm_hour = data[RTC_HOUR] & 0x0f;
if (data[RTC_HOUR] & HOUR_PM_MASK)
tm->tm_hour += 12;
}
/* Only a single bit is set in data[], so fls() would be equivalent */
tm->tm_wday = ffs(data[RTC_WEEKDAY] & mask) - 1;
tm->tm_mday = data[RTC_DATE] & 0x1f;
tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1;
tm->tm_year = (data[RTC_YEAR] & mask) + 100;
tm->tm_yday = 0;
tm->tm_isdst = 0;
}
static int max77686_rtc_tm_to_data(struct rtc_time *tm, u8 *data)
{
data[RTC_SEC] = tm->tm_sec;
data[RTC_MIN] = tm->tm_min;
data[RTC_HOUR] = tm->tm_hour;
data[RTC_WEEKDAY] = 1 << tm->tm_wday;
data[RTC_DATE] = tm->tm_mday;
data[RTC_MONTH] = tm->tm_mon + 1;
data[RTC_YEAR] = tm->tm_year > 100 ? (tm->tm_year - 100) : 0;
if (tm->tm_year < 100) {
pr_warn("RTC cannot handle the year %d. Assume it's 2000.\n",
1900 + tm->tm_year);
return -EINVAL;
}
return 0;
}
static int max77686_rtc_update(struct max77686_rtc_info *info,
enum MAX77686_RTC_OP op)
{
int ret;
unsigned int data;
unsigned long delay = info->drv_data->delay;
if (op == MAX77686_RTC_WRITE)
data = 1 << RTC_UDR_SHIFT;
else
data = 1 << RTC_RBUDR_SHIFT;
ret = regmap_update_bits(info->max77686->rtc_regmap,
info->drv_data->map[REG_RTC_UPDATE0],
data, data);
if (ret < 0)
dev_err(info->dev, "%s: fail to write update reg(ret=%d, data=0x%x)\n",
__func__, ret, data);
else {
/* Minimum delay required before RTC update. */
usleep_range(delay, delay * 2);
}
return ret;
}
static int max77686_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct max77686_rtc_info *info = dev_get_drvdata(dev);
u8 data[RTC_NR_TIME];
int ret;
mutex_lock(&info->lock);
ret = max77686_rtc_update(info, MAX77686_RTC_READ);
if (ret < 0)
goto out;
ret = regmap_bulk_read(info->max77686->rtc_regmap,
info->drv_data->map[REG_RTC_SEC],
data, ARRAY_SIZE(data));
if (ret < 0) {
dev_err(info->dev, "%s: fail to read time reg(%d)\n", __func__, ret);
goto out;
}
max77686_rtc_data_to_tm(data, tm, info);
ret = rtc_valid_tm(tm);
out:
mutex_unlock(&info->lock);
return ret;
}
static int max77686_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct max77686_rtc_info *info = dev_get_drvdata(dev);
u8 data[RTC_NR_TIME];
int ret;
ret = max77686_rtc_tm_to_data(tm, data);
if (ret < 0)
return ret;
mutex_lock(&info->lock);
ret = regmap_bulk_write(info->max77686->rtc_regmap,
info->drv_data->map[REG_RTC_SEC],
data, ARRAY_SIZE(data));
if (ret < 0) {
dev_err(info->dev, "%s: fail to write time reg(%d)\n", __func__,
ret);
goto out;
}
ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
out:
mutex_unlock(&info->lock);
return ret;
}
static int max77686_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct max77686_rtc_info *info = dev_get_drvdata(dev);
u8 data[RTC_NR_TIME];
unsigned int val;
const unsigned int *map = info->drv_data->map;
int i, ret;
mutex_lock(&info->lock);
ret = max77686_rtc_update(info, MAX77686_RTC_READ);
if (ret < 0)
goto out;
ret = regmap_bulk_read(info->max77686->rtc_regmap,
map[REG_ALARM1_SEC], data, ARRAY_SIZE(data));
if (ret < 0) {
dev_err(info->dev, "%s:%d fail to read alarm reg(%d)\n",
__func__, __LINE__, ret);
goto out;
}
max77686_rtc_data_to_tm(data, &alrm->time, info);
alrm->enabled = 0;
for (i = 0; i < ARRAY_SIZE(data); i++) {
if (data[i] & ALARM_ENABLE_MASK) {
alrm->enabled = 1;
break;
}
}
alrm->pending = 0;
ret = regmap_read(info->max77686->regmap, MAX77686_REG_STATUS2, &val);
if (ret < 0) {
dev_err(info->dev, "%s:%d fail to read status2 reg(%d)\n",
__func__, __LINE__, ret);
goto out;
}
if (val & (1 << 4)) /* RTCA1 */
alrm->pending = 1;
out:
mutex_unlock(&info->lock);
return ret;
}
static int max77686_rtc_stop_alarm(struct max77686_rtc_info *info)
{
u8 data[RTC_NR_TIME];
int ret, i;
struct rtc_time tm;
const unsigned int *map = info->drv_data->map;
if (!mutex_is_locked(&info->lock))
dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
ret = max77686_rtc_update(info, MAX77686_RTC_READ);
if (ret < 0)
goto out;
ret = regmap_bulk_read(info->max77686->rtc_regmap,
map[REG_ALARM1_SEC], data, ARRAY_SIZE(data));
if (ret < 0) {
dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
__func__, ret);
goto out;
}
max77686_rtc_data_to_tm(data, &tm, info);
for (i = 0; i < ARRAY_SIZE(data); i++)
data[i] &= ~ALARM_ENABLE_MASK;
ret = regmap_bulk_write(info->max77686->rtc_regmap,
map[REG_ALARM1_SEC], data, ARRAY_SIZE(data));
if (ret < 0) {
dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
__func__, ret);
goto out;
}
ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
out:
return ret;
}
static int max77686_rtc_start_alarm(struct max77686_rtc_info *info)
{
u8 data[RTC_NR_TIME];
int ret;
struct rtc_time tm;
const unsigned int *map = info->drv_data->map;
if (!mutex_is_locked(&info->lock))
dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
ret = max77686_rtc_update(info, MAX77686_RTC_READ);
if (ret < 0)
goto out;
ret = regmap_bulk_read(info->max77686->rtc_regmap,
map[REG_ALARM1_SEC], data, ARRAY_SIZE(data));
if (ret < 0) {
dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
__func__, ret);
goto out;
}
max77686_rtc_data_to_tm(data, &tm, info);
data[RTC_SEC] |= (1 << ALARM_ENABLE_SHIFT);
data[RTC_MIN] |= (1 << ALARM_ENABLE_SHIFT);
data[RTC_HOUR] |= (1 << ALARM_ENABLE_SHIFT);
data[RTC_WEEKDAY] &= ~ALARM_ENABLE_MASK;
if (data[RTC_MONTH] & 0xf)
data[RTC_MONTH] |= (1 << ALARM_ENABLE_SHIFT);
if (data[RTC_YEAR] & info->drv_data->mask)
data[RTC_YEAR] |= (1 << ALARM_ENABLE_SHIFT);
if (data[RTC_DATE] & 0x1f)
data[RTC_DATE] |= (1 << ALARM_ENABLE_SHIFT);
ret = regmap_bulk_write(info->max77686->rtc_regmap,
map[REG_ALARM1_SEC], data, ARRAY_SIZE(data));
if (ret < 0) {
dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
__func__, ret);
goto out;
}
ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
out:
return ret;
}
static int max77686_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct max77686_rtc_info *info = dev_get_drvdata(dev);
u8 data[RTC_NR_TIME];
int ret;
ret = max77686_rtc_tm_to_data(&alrm->time, data);
if (ret < 0)
return ret;
mutex_lock(&info->lock);
ret = max77686_rtc_stop_alarm(info);
if (ret < 0)
goto out;
ret = regmap_bulk_write(info->max77686->rtc_regmap,
info->drv_data->map[REG_ALARM1_SEC],
data, ARRAY_SIZE(data));
if (ret < 0) {
dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
__func__, ret);
goto out;
}
ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
if (ret < 0)
goto out;
if (alrm->enabled)
ret = max77686_rtc_start_alarm(info);
out:
mutex_unlock(&info->lock);
return ret;
}
static int max77686_rtc_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct max77686_rtc_info *info = dev_get_drvdata(dev);
int ret;
mutex_lock(&info->lock);
if (enabled)
ret = max77686_rtc_start_alarm(info);
else
ret = max77686_rtc_stop_alarm(info);
mutex_unlock(&info->lock);
return ret;
}
static irqreturn_t max77686_rtc_alarm_irq(int irq, void *data)
{
struct max77686_rtc_info *info = data;
dev_info(info->dev, "%s:irq(%d)\n", __func__, irq);
rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
return IRQ_HANDLED;
}
static const struct rtc_class_ops max77686_rtc_ops = {
.read_time = max77686_rtc_read_time,
.set_time = max77686_rtc_set_time,
.read_alarm = max77686_rtc_read_alarm,
.set_alarm = max77686_rtc_set_alarm,
.alarm_irq_enable = max77686_rtc_alarm_irq_enable,
};
static int max77686_rtc_init_reg(struct max77686_rtc_info *info)
{
u8 data[2];
int ret;
/* Set RTC control register : Binary mode, 24hour mdoe */
data[0] = (1 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
data[1] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
info->rtc_24hr_mode = 1;
ret = regmap_bulk_write(info->max77686->rtc_regmap,
info->drv_data->map[REG_RTC_CONTROLM],
data, ARRAY_SIZE(data));
if (ret < 0) {
dev_err(info->dev, "%s: fail to write controlm reg(%d)\n",
__func__, ret);
return ret;
}
ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
return ret;
}
static int max77686_rtc_probe(struct platform_device *pdev)
{
struct max77686_dev *max77686 = dev_get_drvdata(pdev->dev.parent);
struct max77686_rtc_info *info;
const struct platform_device_id *id = platform_get_device_id(pdev);
int ret;
dev_info(&pdev->dev, "%s\n", __func__);
info = devm_kzalloc(&pdev->dev, sizeof(struct max77686_rtc_info),
GFP_KERNEL);
if (!info)
return -ENOMEM;
mutex_init(&info->lock);
info->dev = &pdev->dev;
info->max77686 = max77686;
info->rtc = max77686->rtc;
info->drv_data = (const struct max77686_rtc_driver_data *)
id->driver_data;
platform_set_drvdata(pdev, info);
ret = max77686_rtc_init_reg(info);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret);
goto err_rtc;
}
device_init_wakeup(&pdev->dev, 1);
info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max77686-rtc",
&max77686_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);
if (ret == 0)
ret = -EINVAL;
goto err_rtc;
}
if (!max77686->rtc_irq_data) {
ret = -EINVAL;
dev_err(&pdev->dev, "%s: no RTC regmap IRQ chip\n", __func__);
goto err_rtc;
}
info->virq = regmap_irq_get_virq(max77686->rtc_irq_data,
MAX77686_RTCIRQ_RTCA1);
if (!info->virq) {
ret = -ENXIO;
goto err_rtc;
}
ret = devm_request_threaded_irq(&pdev->dev, info->virq, NULL,
max77686_rtc_alarm_irq, 0, "rtc-alarm1", info);
if (ret < 0)
dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
info->virq, ret);
err_rtc:
return ret;
}
#ifdef CONFIG_PM_SLEEP
static int max77686_rtc_suspend(struct device *dev)
{
if (device_may_wakeup(dev)) {
struct max77686_rtc_info *info = dev_get_drvdata(dev);
return enable_irq_wake(info->virq);
}
return 0;
}
static int max77686_rtc_resume(struct device *dev)
{
if (device_may_wakeup(dev)) {
struct max77686_rtc_info *info = dev_get_drvdata(dev);
return disable_irq_wake(info->virq);
}
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(max77686_rtc_pm_ops,
max77686_rtc_suspend, max77686_rtc_resume);
static const struct platform_device_id rtc_id[] = {
{ "max77686-rtc", .driver_data = (kernel_ulong_t)&max77686_drv_data, },
{},
};
MODULE_DEVICE_TABLE(platform, rtc_id);
static struct platform_driver max77686_rtc_driver = {
.driver = {
.name = "max77686-rtc",
.pm = &max77686_rtc_pm_ops,
},
.probe = max77686_rtc_probe,
.id_table = rtc_id,
};
module_platform_driver(max77686_rtc_driver);
MODULE_DESCRIPTION("Maxim MAX77686 RTC driver");
MODULE_AUTHOR("Chiwoong Byun <woong.byun@samsung.com>");
MODULE_LICENSE("GPL");
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