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linux/drivers/rtc/rtc-da9052.c
Bartosz Golaszewski fdcfd85433 rtc: rework rtc_register_device() resource management 
rtc_register_device() is a managed interface but it doesn't use devres
by itself - instead it marks an rtc_device as "registered" and the devres
callback for devm_rtc_allocate_device() takes care of resource release.

This doesn't correspond with the design behind devres where managed
structures should not be aware of being managed. The correct solution
here is to register a separate devres callback for unregistering the
device.

While at it: rename rtc_register_device() to devm_rtc_register_device()
and add it to the list of managed interfaces in devres.rst. This way we
can avoid any potential confusion of driver developers who may expect
there to exist a corresponding unregister function.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201109163409.24301-8-brgl@bgdev.pl
2020-11-19 12:50:12 +01:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Real time clock driver for DA9052
*
* Copyright(c) 2012 Dialog Semiconductor Ltd.
*
* Author: Dajun Dajun Chen <dajun.chen@diasemi.com>
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/mfd/da9052/da9052.h>
#include <linux/mfd/da9052/reg.h>
#define rtc_err(rtc, fmt, ...) \
dev_err(rtc->da9052->dev, "%s: " fmt, __func__, ##__VA_ARGS__)
#define DA9052_GET_TIME_RETRIES 5
struct da9052_rtc {
struct rtc_device *rtc;
struct da9052 *da9052;
};
static int da9052_rtc_enable_alarm(struct da9052_rtc *rtc, bool enable)
{
int ret;
if (enable) {
ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON,
DA9052_ALARM_Y_ALARM_ON);
if (ret != 0)
rtc_err(rtc, "Failed to enable ALM: %d\n", ret);
} else {
ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, 0);
if (ret != 0)
rtc_err(rtc, "Write error: %d\n", ret);
}
return ret;
}
static irqreturn_t da9052_rtc_irq(int irq, void *data)
{
struct da9052_rtc *rtc = data;
rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
return IRQ_HANDLED;
}
static int da9052_read_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
{
int ret;
uint8_t v[2][5];
int idx = 1;
int timeout = DA9052_GET_TIME_RETRIES;
ret = da9052_group_read(rtc->da9052, DA9052_ALARM_MI_REG, 5, &v[0][0]);
if (ret) {
rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
return ret;
}
do {
ret = da9052_group_read(rtc->da9052,
DA9052_ALARM_MI_REG, 5, &v[idx][0]);
if (ret) {
rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
return ret;
}
if (memcmp(&v[0][0], &v[1][0], 5) == 0) {
rtc_tm->tm_year = (v[0][4] & DA9052_RTC_YEAR) + 100;
rtc_tm->tm_mon = (v[0][3] & DA9052_RTC_MONTH) - 1;
rtc_tm->tm_mday = v[0][2] & DA9052_RTC_DAY;
rtc_tm->tm_hour = v[0][1] & DA9052_RTC_HOUR;
rtc_tm->tm_min = v[0][0] & DA9052_RTC_MIN;
rtc_tm->tm_sec = 0;
ret = rtc_valid_tm(rtc_tm);
return ret;
}
idx = (1-idx);
msleep(20);
} while (timeout--);
rtc_err(rtc, "Timed out reading alarm time\n");
return -EIO;
}
static int da9052_set_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
{
struct da9052 *da9052 = rtc->da9052;
unsigned long alm_time;
int ret;
uint8_t v[3];
alm_time = rtc_tm_to_time64(rtc_tm);
if (rtc_tm->tm_sec > 0) {
alm_time += 60 - rtc_tm->tm_sec;
rtc_time64_to_tm(alm_time, rtc_tm);
}
BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */
rtc_tm->tm_year -= 100;
rtc_tm->tm_mon += 1;
ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG,
DA9052_RTC_MIN, rtc_tm->tm_min);
if (ret != 0) {
rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret);
return ret;
}
v[0] = rtc_tm->tm_hour;
v[1] = rtc_tm->tm_mday;
v[2] = rtc_tm->tm_mon;
ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v);
if (ret < 0)
return ret;
ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
DA9052_RTC_YEAR, rtc_tm->tm_year);
if (ret != 0)
rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret);
return ret;
}
static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc)
{
int ret;
ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG);
if (ret < 0) {
rtc_err(rtc, "Failed to read ALM: %d\n", ret);
return ret;
}
return !!(ret&DA9052_ALARM_Y_ALARM_ON);
}
static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
{
struct da9052_rtc *rtc = dev_get_drvdata(dev);
int ret;
uint8_t v[2][6];
int idx = 1;
int timeout = DA9052_GET_TIME_RETRIES;
ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, &v[0][0]);
if (ret) {
rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
return ret;
}
do {
ret = da9052_group_read(rtc->da9052,
DA9052_COUNT_S_REG, 6, &v[idx][0]);
if (ret) {
rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
return ret;
}
if (memcmp(&v[0][0], &v[1][0], 6) == 0) {
rtc_tm->tm_year = (v[0][5] & DA9052_RTC_YEAR) + 100;
rtc_tm->tm_mon = (v[0][4] & DA9052_RTC_MONTH) - 1;
rtc_tm->tm_mday = v[0][3] & DA9052_RTC_DAY;
rtc_tm->tm_hour = v[0][2] & DA9052_RTC_HOUR;
rtc_tm->tm_min = v[0][1] & DA9052_RTC_MIN;
rtc_tm->tm_sec = v[0][0] & DA9052_RTC_SEC;
return 0;
}
idx = (1-idx);
msleep(20);
} while (timeout--);
rtc_err(rtc, "Timed out reading time\n");
return -EIO;
}
static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct da9052_rtc *rtc;
uint8_t v[6];
int ret;
/* DA9052 only has 6 bits for year - to represent 2000-2063 */
if ((tm->tm_year < 100) || (tm->tm_year > 163))
return -EINVAL;
rtc = dev_get_drvdata(dev);
v[0] = tm->tm_sec;
v[1] = tm->tm_min;
v[2] = tm->tm_hour;
v[3] = tm->tm_mday;
v[4] = tm->tm_mon + 1;
v[5] = tm->tm_year - 100;
ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
if (ret < 0)
rtc_err(rtc, "failed to set RTC time: %d\n", ret);
return ret;
}
static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
int ret;
struct rtc_time *tm = &alrm->time;
struct da9052_rtc *rtc = dev_get_drvdata(dev);
ret = da9052_read_alarm(rtc, tm);
if (ret < 0) {
rtc_err(rtc, "failed to read RTC alarm: %d\n", ret);
return ret;
}
alrm->enabled = da9052_rtc_get_alarm_status(rtc);
return 0;
}
static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
int ret;
struct rtc_time *tm = &alrm->time;
struct da9052_rtc *rtc = dev_get_drvdata(dev);
/* DA9052 only has 6 bits for year - to represent 2000-2063 */
if ((tm->tm_year < 100) || (tm->tm_year > 163))
return -EINVAL;
ret = da9052_rtc_enable_alarm(rtc, 0);
if (ret < 0)
return ret;
ret = da9052_set_alarm(rtc, tm);
if (ret < 0)
return ret;
ret = da9052_rtc_enable_alarm(rtc, 1);
return ret;
}
static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct da9052_rtc *rtc = dev_get_drvdata(dev);
return da9052_rtc_enable_alarm(rtc, enabled);
}
static const struct rtc_class_ops da9052_rtc_ops = {
.read_time = da9052_rtc_read_time,
.set_time = da9052_rtc_set_time,
.read_alarm = da9052_rtc_read_alarm,
.set_alarm = da9052_rtc_set_alarm,
.alarm_irq_enable = da9052_rtc_alarm_irq_enable,
};
static int da9052_rtc_probe(struct platform_device *pdev)
{
struct da9052_rtc *rtc;
int ret;
rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL);
if (!rtc)
return -ENOMEM;
rtc->da9052 = dev_get_drvdata(pdev->dev.parent);
platform_set_drvdata(pdev, rtc);
ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE);
if (ret < 0) {
rtc_err(rtc,
"Failed to setup RTC battery charging: %d\n", ret);
return ret;
}
ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
DA9052_ALARM_Y_TICK_ON, 0);
if (ret != 0)
rtc_err(rtc, "Failed to disable TICKS: %d\n", ret);
device_init_wakeup(&pdev->dev, true);
rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(rtc->rtc))
return PTR_ERR(rtc->rtc);
rtc->rtc->ops = &da9052_rtc_ops;
rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
rtc->rtc->range_max = RTC_TIMESTAMP_END_2063;
ret = devm_rtc_register_device(rtc->rtc);
if (ret)
return ret;
ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM",
da9052_rtc_irq, rtc);
if (ret != 0) {
rtc_err(rtc, "irq registration failed: %d\n", ret);
return ret;
}
return 0;
}
static struct platform_driver da9052_rtc_driver = {
.probe = da9052_rtc_probe,
.driver = {
.name = "da9052-rtc",
},
};
module_platform_driver(da9052_rtc_driver);
MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9052-rtc");
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