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linux/drivers/rtc/rtc-rc5t619.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+
/*
* drivers/rtc/rtc-rc5t619.c
*
* Real time clock driver for RICOH RC5T619 power management chip.
*
* Copyright (C) 2019 Andreas Kemnade
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mfd/rn5t618.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <linux/irqdomain.h>
struct rc5t619_rtc {
int irq;
struct rtc_device *rtc;
struct rn5t618 *rn5t618;
};
#define CTRL1_ALARM_ENABLED 0x40
#define CTRL1_24HR 0x20
#define CTRL1_PERIODIC_MASK 0xf
#define CTRL2_PON 0x10
#define CTRL2_ALARM_STATUS 0x80
#define CTRL2_CTFG 0x4
#define CTRL2_CTC 0x1
#define MONTH_CENTFLAG 0x80
#define HOUR_PMFLAG 0x20
#define MDAY_DAL_EXT 0x80
static uint8_t rtc5t619_12hour_bcd2bin(uint8_t hour)
{
if (hour & HOUR_PMFLAG) {
hour = bcd2bin(hour & ~HOUR_PMFLAG);
return hour == 12 ? 12 : 12 + hour;
}
hour = bcd2bin(hour);
return hour == 12 ? 0 : hour;
}
static uint8_t rtc5t619_12hour_bin2bcd(uint8_t hour)
{
if (!hour)
return 0x12;
if (hour < 12)
return bin2bcd(hour);
if (hour == 12)
return 0x12 | HOUR_PMFLAG;
return bin2bcd(hour - 12) | HOUR_PMFLAG;
}
static int rc5t619_rtc_periodic_disable(struct device *dev)
{
struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
int err;
/* disable function */
err = regmap_update_bits(rtc->rn5t618->regmap,
RN5T618_RTC_CTRL1, CTRL1_PERIODIC_MASK, 0);
if (err < 0)
return err;
/* clear alarm flag and CTFG */
err = regmap_update_bits(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2,
CTRL2_ALARM_STATUS | CTRL2_CTFG | CTRL2_CTC,
0);
if (err < 0)
return err;
return 0;
}
/* things to be done once after power on */
static int rc5t619_rtc_pon_setup(struct device *dev)
{
struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
int err;
unsigned int reg_data;
err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &reg_data);
if (err < 0)
return err;
/* clear VDET PON */
reg_data &= ~(CTRL2_PON | CTRL2_CTC | 0x4a); /* 0101-1011 */
reg_data |= 0x20; /* 0010-0000 */
err = regmap_write(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, reg_data);
if (err < 0)
return err;
/* clearing RTC Adjust register */
err = regmap_write(rtc->rn5t618->regmap, RN5T618_RTC_ADJUST, 0);
if (err)
return err;
return regmap_update_bits(rtc->rn5t618->regmap,
RN5T618_RTC_CTRL1,
CTRL1_24HR, CTRL1_24HR);
}
static int rc5t619_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
u8 buff[7];
int err;
int cent_flag;
unsigned int ctrl1;
unsigned int ctrl2;
err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
if (err < 0)
return err;
if (ctrl2 & CTRL2_PON)
return -EINVAL;
err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
if (err < 0)
return err;
err = regmap_bulk_read(rtc->rn5t618->regmap, RN5T618_RTC_SECONDS,
buff, sizeof(buff));
if (err < 0)
return err;
if (buff[5] & MONTH_CENTFLAG)
cent_flag = 1;
else
cent_flag = 0;
tm->tm_sec = bcd2bin(buff[0]);
tm->tm_min = bcd2bin(buff[1]);
if (ctrl1 & CTRL1_24HR)
tm->tm_hour = bcd2bin(buff[2]);
else
tm->tm_hour = rtc5t619_12hour_bcd2bin(buff[2]);
tm->tm_wday = bcd2bin(buff[3]);
tm->tm_mday = bcd2bin(buff[4]);
tm->tm_mon = bcd2bin(buff[5] & 0x1f) - 1; /* back to system 0-11 */
tm->tm_year = bcd2bin(buff[6]) + 100 * cent_flag;
return 0;
}
static int rc5t619_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
u8 buff[7];
int err;
int cent_flag;
unsigned int ctrl1;
unsigned int ctrl2;
err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
if (err < 0)
return err;
if (ctrl2 & CTRL2_PON)
rc5t619_rtc_pon_setup(dev);
err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
if (err < 0)
return err;
if (tm->tm_year >= 100)
cent_flag = 1;
else
cent_flag = 0;
buff[0] = bin2bcd(tm->tm_sec);
buff[1] = bin2bcd(tm->tm_min);
if (ctrl1 & CTRL1_24HR)
buff[2] = bin2bcd(tm->tm_hour);
else
buff[2] = rtc5t619_12hour_bin2bcd(tm->tm_hour);
buff[3] = bin2bcd(tm->tm_wday);
buff[4] = bin2bcd(tm->tm_mday);
buff[5] = bin2bcd(tm->tm_mon + 1); /* system set 0-11 */
buff[6] = bin2bcd(tm->tm_year - cent_flag * 100);
if (cent_flag)
buff[5] |= MONTH_CENTFLAG;
err = regmap_bulk_write(rtc->rn5t618->regmap, RN5T618_RTC_SECONDS,
buff, sizeof(buff));
if (err < 0) {
dev_err(dev, "failed to program new time: %d\n", err);
return err;
}
return 0;
}
/* 0-disable, 1-enable */
static int rc5t619_rtc_alarm_enable(struct device *dev, unsigned int enabled)
{
struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
return regmap_update_bits(rtc->rn5t618->regmap,
RN5T618_RTC_CTRL1,
CTRL1_ALARM_ENABLED,
enabled ? CTRL1_ALARM_ENABLED : 0);
}
static int rc5t619_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
u8 buff[6];
unsigned int buff_cent;
int err;
int cent_flag;
unsigned int ctrl1;
err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
if (err)
return err;
err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_MONTH, &buff_cent);
if (err < 0) {
dev_err(dev, "failed to read time: %d\n", err);
return err;
}
if (buff_cent & MONTH_CENTFLAG)
cent_flag = 1;
else
cent_flag = 0;
err = regmap_bulk_read(rtc->rn5t618->regmap, RN5T618_RTC_ALARM_Y_SEC,
buff, sizeof(buff));
if (err)
return err;
buff[3] = buff[3] & 0x3f;
alrm->time.tm_sec = bcd2bin(buff[0]);
alrm->time.tm_min = bcd2bin(buff[1]);
if (ctrl1 & CTRL1_24HR)
alrm->time.tm_hour = bcd2bin(buff[2]);
else
alrm->time.tm_hour = rtc5t619_12hour_bcd2bin(buff[2]);
alrm->time.tm_mday = bcd2bin(buff[3]);
alrm->time.tm_mon = bcd2bin(buff[4]) - 1;
alrm->time.tm_year = bcd2bin(buff[5]) + 100 * cent_flag;
alrm->enabled = !!(ctrl1 & CTRL1_ALARM_ENABLED);
dev_dbg(dev, "read alarm: %ptR\n", &alrm->time);
return 0;
}
static int rc5t619_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
u8 buff[6];
int err;
int cent_flag;
unsigned int ctrl1;
err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1);
if (err)
return err;
err = rc5t619_rtc_alarm_enable(dev, 0);
if (err < 0)
return err;
if (rtc->irq == -1)
return -EINVAL;
if (alrm->enabled == 0)
return 0;
if (alrm->time.tm_year >= 100)
cent_flag = 1;
else
cent_flag = 0;
alrm->time.tm_mon += 1;
buff[0] = bin2bcd(alrm->time.tm_sec);
buff[1] = bin2bcd(alrm->time.tm_min);
if (ctrl1 & CTRL1_24HR)
buff[2] = bin2bcd(alrm->time.tm_hour);
else
buff[2] = rtc5t619_12hour_bin2bcd(alrm->time.tm_hour);
buff[3] = bin2bcd(alrm->time.tm_mday);
buff[4] = bin2bcd(alrm->time.tm_mon);
buff[5] = bin2bcd(alrm->time.tm_year - 100 * cent_flag);
buff[3] |= MDAY_DAL_EXT;
err = regmap_bulk_write(rtc->rn5t618->regmap, RN5T618_RTC_ALARM_Y_SEC,
buff, sizeof(buff));
if (err < 0)
return err;
return rc5t619_rtc_alarm_enable(dev, alrm->enabled);
}
static const struct rtc_class_ops rc5t619_rtc_ops = {
.read_time = rc5t619_rtc_read_time,
.set_time = rc5t619_rtc_set_time,
.set_alarm = rc5t619_rtc_set_alarm,
.read_alarm = rc5t619_rtc_read_alarm,
.alarm_irq_enable = rc5t619_rtc_alarm_enable,
};
static int rc5t619_rtc_alarm_flag_clr(struct device *dev)
{
struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
/* clear alarm-D status bits.*/
return regmap_update_bits(rtc->rn5t618->regmap,
RN5T618_RTC_CTRL2,
CTRL2_ALARM_STATUS | CTRL2_CTC, 0);
}
static irqreturn_t rc5t619_rtc_irq(int irq, void *data)
{
struct device *dev = data;
struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
rc5t619_rtc_alarm_flag_clr(dev);
rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
return IRQ_HANDLED;
}
static int rc5t619_rtc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent);
struct rc5t619_rtc *rtc;
unsigned int ctrl2;
int err;
rtc = devm_kzalloc(dev, sizeof(*rtc), GFP_KERNEL);
if (!rtc)
return -ENOMEM;
rtc->rn5t618 = rn5t618;
dev_set_drvdata(dev, rtc);
rtc->irq = -1;
if (rn5t618->irq_data)
rtc->irq = regmap_irq_get_virq(rn5t618->irq_data,
RN5T618_IRQ_RTC);
if (rtc->irq < 0)
rtc->irq = -1;
err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
if (err < 0)
return err;
/* disable rtc periodic function */
err = rc5t619_rtc_periodic_disable(&pdev->dev);
if (err)
return err;
if (ctrl2 & CTRL2_PON) {
err = rc5t619_rtc_alarm_flag_clr(&pdev->dev);
if (err)
return err;
}
rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(rtc->rtc)) {
err = PTR_ERR(rtc->rtc);
dev_err(dev, "RTC device register: err %d\n", err);
return err;
}
rtc->rtc->ops = &rc5t619_rtc_ops;
rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_1900;
rtc->rtc->range_max = RTC_TIMESTAMP_END_2099;
/* set interrupt and enable it */
if (rtc->irq != -1) {
err = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
rc5t619_rtc_irq,
IRQF_ONESHOT,
"rtc-rc5t619",
&pdev->dev);
if (err < 0) {
dev_err(&pdev->dev, "request IRQ:%d fail\n", rtc->irq);
rtc->irq = -1;
err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
if (err)
return err;
} else {
/* enable wake */
device_init_wakeup(&pdev->dev, 1);
enable_irq_wake(rtc->irq);
}
} else {
/* system don't want to using alarm interrupt, so close it */
err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
if (err)
return err;
dev_warn(&pdev->dev, "rc5t619 interrupt is disabled\n");
}
return devm_rtc_register_device(rtc->rtc);
}
static struct platform_driver rc5t619_rtc_driver = {
.driver = {
.name = "rc5t619-rtc",
},
.probe = rc5t619_rtc_probe,
};
module_platform_driver(rc5t619_rtc_driver);
MODULE_ALIAS("platform:rc5t619-rtc");
MODULE_DESCRIPTION("RICOH RC5T619 RTC driver");
MODULE_LICENSE("GPL");
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