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linux/drivers/rtc/rtc-max8997.c
Christophe JAILLET 41ef387820 rtc: max8997: Fix the returned value in case of error in 'max8997_rtc_read_alarm()' 
In case of error, we return 0.
This is spurious and not consistent with the other functions of the driver.
Propagate the error code instead.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-11-22 18:11:35 +01:00

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// SPDX-License-Identifier: GPL-2.0+
//
// RTC driver for Maxim MAX8997
//
// Copyright (C) 2013 Samsung Electronics Co.Ltd
//
// based on rtc-max8998.c
#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/max8997-private.h>
#include <linux/irqdomain.h>
/* Module parameter for WTSR function control */
static int wtsr_en = 1;
module_param(wtsr_en, int, 0444);
MODULE_PARM_DESC(wtsr_en, "Watchdog Timeout & Software Reset (default=on)");
/* Module parameter for SMPL function control */
static int smpl_en = 1;
module_param(smpl_en, int, 0444);
MODULE_PARM_DESC(smpl_en, "Sudden Momentary Power Loss (default=on)");
/* 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)
/* WTSR and SMPL Register */
#define WTSRT_SHIFT 0
#define SMPLT_SHIFT 2
#define WTSR_EN_SHIFT 6
#define SMPL_EN_SHIFT 7
#define WTSRT_MASK (3 << WTSRT_SHIFT)
#define SMPLT_MASK (3 << SMPLT_SHIFT)
#define WTSR_EN_MASK (1 << WTSR_EN_SHIFT)
#define SMPL_EN_MASK (1 << SMPL_EN_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 max8997_rtc_info {
struct device *dev;
struct max8997_dev *max8997;
struct i2c_client *rtc;
struct rtc_device *rtc_dev;
struct mutex lock;
int virq;
int rtc_24hr_mode;
};
static void max8997_rtc_data_to_tm(u8 *data, struct rtc_time *tm,
int rtc_24hr_mode)
{
tm->tm_sec = data[RTC_SEC] & 0x7f;
tm->tm_min = data[RTC_MIN] & 0x7f;
if (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;
}
tm->tm_wday = fls(data[RTC_WEEKDAY] & 0x7f) - 1;
tm->tm_mday = data[RTC_DATE] & 0x1f;
tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1;
tm->tm_year = (data[RTC_YEAR] & 0x7f) + 100;
tm->tm_yday = 0;
tm->tm_isdst = 0;
}
static int max8997_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 inline int max8997_rtc_set_update_reg(struct max8997_rtc_info *info)
{
int ret;
ret = max8997_write_reg(info->rtc, MAX8997_RTC_UPDATE1,
RTC_UDR_MASK);
if (ret < 0)
dev_err(info->dev, "%s: fail to write update reg(%d)\n",
__func__, ret);
else {
/* Minimum 16ms delay required before RTC update.
* Otherwise, we may read and update based on out-of-date
* value */
msleep(20);
}
return ret;
}
static int max8997_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct max8997_rtc_info *info = dev_get_drvdata(dev);
u8 data[RTC_NR_TIME];
int ret;
mutex_lock(&info->lock);
ret = max8997_bulk_read(info->rtc, MAX8997_RTC_SEC, RTC_NR_TIME, data);
mutex_unlock(&info->lock);
if (ret < 0) {
dev_err(info->dev, "%s: fail to read time reg(%d)\n", __func__,
ret);
return ret;
}
max8997_rtc_data_to_tm(data, tm, info->rtc_24hr_mode);
return 0;
}
static int max8997_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct max8997_rtc_info *info = dev_get_drvdata(dev);
u8 data[RTC_NR_TIME];
int ret;
ret = max8997_rtc_tm_to_data(tm, data);
if (ret < 0)
return ret;
mutex_lock(&info->lock);
ret = max8997_bulk_write(info->rtc, MAX8997_RTC_SEC, RTC_NR_TIME, data);
if (ret < 0) {
dev_err(info->dev, "%s: fail to write time reg(%d)\n", __func__,
ret);
goto out;
}
ret = max8997_rtc_set_update_reg(info);
out:
mutex_unlock(&info->lock);
return ret;
}
static int max8997_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct max8997_rtc_info *info = dev_get_drvdata(dev);
u8 data[RTC_NR_TIME];
u8 val;
int i, ret;
mutex_lock(&info->lock);
ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
data);
if (ret < 0) {
dev_err(info->dev, "%s:%d fail to read alarm reg(%d)\n",
__func__, __LINE__, ret);
goto out;
}
max8997_rtc_data_to_tm(data, &alrm->time, info->rtc_24hr_mode);
alrm->enabled = 0;
for (i = 0; i < RTC_NR_TIME; i++) {
if (data[i] & ALARM_ENABLE_MASK) {
alrm->enabled = 1;
break;
}
}
alrm->pending = 0;
ret = max8997_read_reg(info->max8997->i2c, MAX8997_REG_STATUS1, &val);
if (ret < 0) {
dev_err(info->dev, "%s:%d fail to read status1 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 max8997_rtc_stop_alarm(struct max8997_rtc_info *info)
{
u8 data[RTC_NR_TIME];
int ret, i;
if (!mutex_is_locked(&info->lock))
dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
data);
if (ret < 0) {
dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
__func__, ret);
goto out;
}
for (i = 0; i < RTC_NR_TIME; i++)
data[i] &= ~ALARM_ENABLE_MASK;
ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
data);
if (ret < 0) {
dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
__func__, ret);
goto out;
}
ret = max8997_rtc_set_update_reg(info);
out:
return ret;
}
static int max8997_rtc_start_alarm(struct max8997_rtc_info *info)
{
u8 data[RTC_NR_TIME];
int ret;
if (!mutex_is_locked(&info->lock))
dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
data);
if (ret < 0) {
dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
__func__, ret);
goto out;
}
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] & 0x7f)
data[RTC_YEAR] |= (1 << ALARM_ENABLE_SHIFT);
if (data[RTC_DATE] & 0x1f)
data[RTC_DATE] |= (1 << ALARM_ENABLE_SHIFT);
ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
data);
if (ret < 0) {
dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
__func__, ret);
goto out;
}
ret = max8997_rtc_set_update_reg(info);
out:
return ret;
}
static int max8997_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct max8997_rtc_info *info = dev_get_drvdata(dev);
u8 data[RTC_NR_TIME];
int ret;
ret = max8997_rtc_tm_to_data(&alrm->time, data);
if (ret < 0)
return ret;
dev_info(info->dev, "%s: %d-%02d-%02d %02d:%02d:%02d\n", __func__,
data[RTC_YEAR] + 2000, data[RTC_MONTH], data[RTC_DATE],
data[RTC_HOUR], data[RTC_MIN], data[RTC_SEC]);
mutex_lock(&info->lock);
ret = max8997_rtc_stop_alarm(info);
if (ret < 0)
goto out;
ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME,
data);
if (ret < 0) {
dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
__func__, ret);
goto out;
}
ret = max8997_rtc_set_update_reg(info);
if (ret < 0)
goto out;
if (alrm->enabled)
ret = max8997_rtc_start_alarm(info);
out:
mutex_unlock(&info->lock);
return ret;
}
static int max8997_rtc_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct max8997_rtc_info *info = dev_get_drvdata(dev);
int ret;
mutex_lock(&info->lock);
if (enabled)
ret = max8997_rtc_start_alarm(info);
else
ret = max8997_rtc_stop_alarm(info);
mutex_unlock(&info->lock);
return ret;
}
static irqreturn_t max8997_rtc_alarm_irq(int irq, void *data)
{
struct max8997_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 max8997_rtc_ops = {
.read_time = max8997_rtc_read_time,
.set_time = max8997_rtc_set_time,
.read_alarm = max8997_rtc_read_alarm,
.set_alarm = max8997_rtc_set_alarm,
.alarm_irq_enable = max8997_rtc_alarm_irq_enable,
};
static void max8997_rtc_enable_wtsr(struct max8997_rtc_info *info, bool enable)
{
int ret;
u8 val, mask;
if (!wtsr_en)
return;
if (enable)
val = (1 << WTSR_EN_SHIFT) | (3 << WTSRT_SHIFT);
else
val = 0;
mask = WTSR_EN_MASK | WTSRT_MASK;
dev_info(info->dev, "%s: %s WTSR\n", __func__,
enable ? "enable" : "disable");
ret = max8997_update_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, val, mask);
if (ret < 0) {
dev_err(info->dev, "%s: fail to update WTSR reg(%d)\n",
__func__, ret);
return;
}
max8997_rtc_set_update_reg(info);
}
static void max8997_rtc_enable_smpl(struct max8997_rtc_info *info, bool enable)
{
int ret;
u8 val, mask;
if (!smpl_en)
return;
if (enable)
val = (1 << SMPL_EN_SHIFT) | (0 << SMPLT_SHIFT);
else
val = 0;
mask = SMPL_EN_MASK | SMPLT_MASK;
dev_info(info->dev, "%s: %s SMPL\n", __func__,
enable ? "enable" : "disable");
ret = max8997_update_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, val, mask);
if (ret < 0) {
dev_err(info->dev, "%s: fail to update SMPL reg(%d)\n",
__func__, ret);
return;
}
max8997_rtc_set_update_reg(info);
val = 0;
max8997_read_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, &val);
pr_info("WTSR_SMPL(0x%02x)\n", val);
}
static int max8997_rtc_init_reg(struct max8997_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 = max8997_bulk_write(info->rtc, MAX8997_RTC_CTRLMASK, 2, data);
if (ret < 0) {
dev_err(info->dev, "%s: fail to write controlm reg(%d)\n",
__func__, ret);
return ret;
}
ret = max8997_rtc_set_update_reg(info);
return ret;
}
static int max8997_rtc_probe(struct platform_device *pdev)
{
struct max8997_dev *max8997 = dev_get_drvdata(pdev->dev.parent);
struct max8997_rtc_info *info;
int ret, virq;
info = devm_kzalloc(&pdev->dev, sizeof(struct max8997_rtc_info),
GFP_KERNEL);
if (!info)
return -ENOMEM;
mutex_init(&info->lock);
info->dev = &pdev->dev;
info->max8997 = max8997;
info->rtc = max8997->rtc;
platform_set_drvdata(pdev, info);
ret = max8997_rtc_init_reg(info);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret);
return ret;
}
max8997_rtc_enable_wtsr(info, true);
max8997_rtc_enable_smpl(info, true);
device_init_wakeup(&pdev->dev, 1);
info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8997-rtc",
&max8997_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);
return ret;
}
virq = irq_create_mapping(max8997->irq_domain, MAX8997_PMICIRQ_RTCA1);
if (!virq) {
dev_err(&pdev->dev, "Failed to create mapping alarm IRQ\n");
ret = -ENXIO;
goto err_out;
}
info->virq = virq;
ret = devm_request_threaded_irq(&pdev->dev, virq, NULL,
max8997_rtc_alarm_irq, 0,
"rtc-alarm0", info);
if (ret < 0)
dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
info->virq, ret);
err_out:
return ret;
}
static void max8997_rtc_shutdown(struct platform_device *pdev)
{
struct max8997_rtc_info *info = platform_get_drvdata(pdev);
max8997_rtc_enable_wtsr(info, false);
max8997_rtc_enable_smpl(info, false);
}
static const struct platform_device_id rtc_id[] = {
{ "max8997-rtc", 0 },
{},
};
MODULE_DEVICE_TABLE(platform, rtc_id);
static struct platform_driver max8997_rtc_driver = {
.driver = {
.name = "max8997-rtc",
},
.probe = max8997_rtc_probe,
.shutdown = max8997_rtc_shutdown,
.id_table = rtc_id,
};
module_platform_driver(max8997_rtc_driver);
MODULE_DESCRIPTION("Maxim MAX8997 RTC driver");
MODULE_AUTHOR("<ms925.kim@samsung.com>");
MODULE_LICENSE("GPL");
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