swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 1c23f9e627a7b412978b4e852793c5e3c3efc555 authored by Linus Torvalds on 22 August 2022, 00:32:54 UTC
Linux 6.0-rc2
Linux 6.0-rc2
Tip revision: 1c23f9e
rtc-s3c.c
// SPDX-License-Identifier: GPL-2.0-only
/* drivers/rtc/rtc-s3c.c
*
* Copyright (c) 2010 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* Copyright (c) 2004,2006 Simtec Electronics
* Ben Dooks, <ben@simtec.co.uk>
* http://armlinux.simtec.co.uk/
*
* S3C2410/S3C2440/S3C24XX Internal RTC Driver
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/clk.h>
#include <linux/log2.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <asm/irq.h>
#include "rtc-s3c.h"
struct s3c_rtc {
struct device *dev;
struct rtc_device *rtc;
void __iomem *base;
struct clk *rtc_clk;
struct clk *rtc_src_clk;
bool alarm_enabled;
const struct s3c_rtc_data *data;
int irq_alarm;
spinlock_t alarm_lock;
bool wake_en;
};
struct s3c_rtc_data {
bool needs_src_clk;
void (*irq_handler) (struct s3c_rtc *info, int mask);
void (*enable) (struct s3c_rtc *info);
void (*disable) (struct s3c_rtc *info);
};
static int s3c_rtc_enable_clk(struct s3c_rtc *info)
{
int ret;
ret = clk_enable(info->rtc_clk);
if (ret)
return ret;
if (info->data->needs_src_clk) {
ret = clk_enable(info->rtc_src_clk);
if (ret) {
clk_disable(info->rtc_clk);
return ret;
}
}
return 0;
}
static void s3c_rtc_disable_clk(struct s3c_rtc *info)
{
if (info->data->needs_src_clk)
clk_disable(info->rtc_src_clk);
clk_disable(info->rtc_clk);
}
/* IRQ Handler */
static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
{
struct s3c_rtc *info = (struct s3c_rtc *)id;
if (info->data->irq_handler)
info->data->irq_handler(info, S3C2410_INTP_ALM);
return IRQ_HANDLED;
}
/* Update control registers */
static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
{
struct s3c_rtc *info = dev_get_drvdata(dev);
unsigned long flags;
unsigned int tmp;
int ret;
dev_dbg(info->dev, "%s: aie=%d\n", __func__, enabled);
ret = s3c_rtc_enable_clk(info);
if (ret)
return ret;
tmp = readb(info->base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
if (enabled)
tmp |= S3C2410_RTCALM_ALMEN;
writeb(tmp, info->base + S3C2410_RTCALM);
spin_lock_irqsave(&info->alarm_lock, flags);
if (info->alarm_enabled && !enabled)
s3c_rtc_disable_clk(info);
else if (!info->alarm_enabled && enabled)
ret = s3c_rtc_enable_clk(info);
info->alarm_enabled = enabled;
spin_unlock_irqrestore(&info->alarm_lock, flags);
s3c_rtc_disable_clk(info);
return ret;
}
/* Read time from RTC and convert it from BCD */
static int s3c_rtc_read_time(struct s3c_rtc *info, struct rtc_time *tm)
{
unsigned int have_retried = 0;
int ret;
ret = s3c_rtc_enable_clk(info);
if (ret)
return ret;
retry_get_time:
tm->tm_min = readb(info->base + S3C2410_RTCMIN);
tm->tm_hour = readb(info->base + S3C2410_RTCHOUR);
tm->tm_mday = readb(info->base + S3C2410_RTCDATE);
tm->tm_mon = readb(info->base + S3C2410_RTCMON);
tm->tm_year = readb(info->base + S3C2410_RTCYEAR);
tm->tm_sec = readb(info->base + S3C2410_RTCSEC);
/*
* The only way to work out whether the system was mid-update
* when we read it is to check the second counter, and if it
* is zero, then we re-try the entire read
*/
if (tm->tm_sec == 0 && !have_retried) {
have_retried = 1;
goto retry_get_time;
}
s3c_rtc_disable_clk(info);
tm->tm_sec = bcd2bin(tm->tm_sec);
tm->tm_min = bcd2bin(tm->tm_min);
tm->tm_hour = bcd2bin(tm->tm_hour);
tm->tm_mday = bcd2bin(tm->tm_mday);
tm->tm_mon = bcd2bin(tm->tm_mon);
tm->tm_year = bcd2bin(tm->tm_year);
return 0;
}
/* Convert time to BCD and write it to RTC */
static int s3c_rtc_write_time(struct s3c_rtc *info, const struct rtc_time *tm)
{
int ret;
ret = s3c_rtc_enable_clk(info);
if (ret)
return ret;
writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_RTCSEC);
writeb(bin2bcd(tm->tm_min), info->base + S3C2410_RTCMIN);
writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_RTCHOUR);
writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_RTCDATE);
writeb(bin2bcd(tm->tm_mon), info->base + S3C2410_RTCMON);
writeb(bin2bcd(tm->tm_year), info->base + S3C2410_RTCYEAR);
s3c_rtc_disable_clk(info);
return 0;
}
static int s3c_rtc_gettime(struct device *dev, struct rtc_time *tm)
{
struct s3c_rtc *info = dev_get_drvdata(dev);
int ret;
ret = s3c_rtc_read_time(info, tm);
if (ret)
return ret;
/* Convert internal representation to actual date/time */
tm->tm_year += 100;
tm->tm_mon -= 1;
dev_dbg(dev, "read time %ptR\n", tm);
return 0;
}
static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
{
struct s3c_rtc *info = dev_get_drvdata(dev);
struct rtc_time rtc_tm = *tm;
dev_dbg(dev, "set time %ptR\n", tm);
/*
* Convert actual date/time to internal representation.
* We get around Y2K by simply not supporting it.
*/
rtc_tm.tm_year -= 100;
rtc_tm.tm_mon += 1;
return s3c_rtc_write_time(info, &rtc_tm);
}
static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct s3c_rtc *info = dev_get_drvdata(dev);
struct rtc_time *alm_tm = &alrm->time;
unsigned int alm_en;
int ret;
ret = s3c_rtc_enable_clk(info);
if (ret)
return ret;
alm_tm->tm_sec = readb(info->base + S3C2410_ALMSEC);
alm_tm->tm_min = readb(info->base + S3C2410_ALMMIN);
alm_tm->tm_hour = readb(info->base + S3C2410_ALMHOUR);
alm_tm->tm_mon = readb(info->base + S3C2410_ALMMON);
alm_tm->tm_mday = readb(info->base + S3C2410_ALMDATE);
alm_tm->tm_year = readb(info->base + S3C2410_ALMYEAR);
alm_en = readb(info->base + S3C2410_RTCALM);
s3c_rtc_disable_clk(info);
alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
dev_dbg(dev, "read alarm %d, %ptR\n", alm_en, alm_tm);
/* decode the alarm enable field */
if (alm_en & S3C2410_RTCALM_SECEN)
alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
if (alm_en & S3C2410_RTCALM_MINEN)
alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
if (alm_en & S3C2410_RTCALM_HOUREN)
alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
if (alm_en & S3C2410_RTCALM_DAYEN)
alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
if (alm_en & S3C2410_RTCALM_MONEN) {
alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
alm_tm->tm_mon -= 1;
}
if (alm_en & S3C2410_RTCALM_YEAREN)
alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
return 0;
}
static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct s3c_rtc *info = dev_get_drvdata(dev);
struct rtc_time *tm = &alrm->time;
unsigned int alrm_en;
int ret;
dev_dbg(dev, "s3c_rtc_setalarm: %d, %ptR\n", alrm->enabled, tm);
ret = s3c_rtc_enable_clk(info);
if (ret)
return ret;
alrm_en = readb(info->base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
writeb(0x00, info->base + S3C2410_RTCALM);
if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
alrm_en |= S3C2410_RTCALM_SECEN;
writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_ALMSEC);
}
if (tm->tm_min < 60 && tm->tm_min >= 0) {
alrm_en |= S3C2410_RTCALM_MINEN;
writeb(bin2bcd(tm->tm_min), info->base + S3C2410_ALMMIN);
}
if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
alrm_en |= S3C2410_RTCALM_HOUREN;
writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_ALMHOUR);
}
if (tm->tm_mon < 12 && tm->tm_mon >= 0) {
alrm_en |= S3C2410_RTCALM_MONEN;
writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_ALMMON);
}
if (tm->tm_mday <= 31 && tm->tm_mday >= 1) {
alrm_en |= S3C2410_RTCALM_DAYEN;
writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_ALMDATE);
}
dev_dbg(dev, "setting S3C2410_RTCALM to %08x\n", alrm_en);
writeb(alrm_en, info->base + S3C2410_RTCALM);
s3c_rtc_setaie(dev, alrm->enabled);
s3c_rtc_disable_clk(info);
return 0;
}
static const struct rtc_class_ops s3c_rtcops = {
.read_time = s3c_rtc_gettime,
.set_time = s3c_rtc_settime,
.read_alarm = s3c_rtc_getalarm,
.set_alarm = s3c_rtc_setalarm,
.alarm_irq_enable = s3c_rtc_setaie,
};
static void s3c24xx_rtc_enable(struct s3c_rtc *info)
{
unsigned int con, tmp;
con = readw(info->base + S3C2410_RTCCON);
/* re-enable the device, and check it is ok */
if ((con & S3C2410_RTCCON_RTCEN) == 0) {
dev_info(info->dev, "rtc disabled, re-enabling\n");
tmp = readw(info->base + S3C2410_RTCCON);
writew(tmp | S3C2410_RTCCON_RTCEN, info->base + S3C2410_RTCCON);
}
if (con & S3C2410_RTCCON_CNTSEL) {
dev_info(info->dev, "removing RTCCON_CNTSEL\n");
tmp = readw(info->base + S3C2410_RTCCON);
writew(tmp & ~S3C2410_RTCCON_CNTSEL,
info->base + S3C2410_RTCCON);
}
if (con & S3C2410_RTCCON_CLKRST) {
dev_info(info->dev, "removing RTCCON_CLKRST\n");
tmp = readw(info->base + S3C2410_RTCCON);
writew(tmp & ~S3C2410_RTCCON_CLKRST,
info->base + S3C2410_RTCCON);
}
}
static void s3c24xx_rtc_disable(struct s3c_rtc *info)
{
unsigned int con;
con = readw(info->base + S3C2410_RTCCON);
con &= ~S3C2410_RTCCON_RTCEN;
writew(con, info->base + S3C2410_RTCCON);
con = readb(info->base + S3C2410_TICNT);
con &= ~S3C2410_TICNT_ENABLE;
writeb(con, info->base + S3C2410_TICNT);
}
static void s3c6410_rtc_disable(struct s3c_rtc *info)
{
unsigned int con;
con = readw(info->base + S3C2410_RTCCON);
con &= ~S3C64XX_RTCCON_TICEN;
con &= ~S3C2410_RTCCON_RTCEN;
writew(con, info->base + S3C2410_RTCCON);
}
static int s3c_rtc_remove(struct platform_device *pdev)
{
struct s3c_rtc *info = platform_get_drvdata(pdev);
s3c_rtc_setaie(info->dev, 0);
if (info->data->needs_src_clk)
clk_unprepare(info->rtc_src_clk);
clk_unprepare(info->rtc_clk);
return 0;
}
static int s3c_rtc_probe(struct platform_device *pdev)
{
struct s3c_rtc *info = NULL;
int ret;
info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
info->dev = &pdev->dev;
info->data = of_device_get_match_data(&pdev->dev);
if (!info->data) {
dev_err(&pdev->dev, "failed getting s3c_rtc_data\n");
return -EINVAL;
}
spin_lock_init(&info->alarm_lock);
platform_set_drvdata(pdev, info);
info->irq_alarm = platform_get_irq(pdev, 0);
if (info->irq_alarm < 0)
return info->irq_alarm;
dev_dbg(&pdev->dev, "s3c2410_rtc: alarm irq %d\n", info->irq_alarm);
/* get the memory region */
info->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(info->base))
return PTR_ERR(info->base);
info->rtc_clk = devm_clk_get(&pdev->dev, "rtc");
if (IS_ERR(info->rtc_clk)) {
ret = PTR_ERR(info->rtc_clk);
if (ret != -EPROBE_DEFER)
dev_err(&pdev->dev, "failed to find rtc clock\n");
else
dev_dbg(&pdev->dev, "probe deferred due to missing rtc clk\n");
return ret;
}
ret = clk_prepare_enable(info->rtc_clk);
if (ret)
return ret;
if (info->data->needs_src_clk) {
info->rtc_src_clk = devm_clk_get(&pdev->dev, "rtc_src");
if (IS_ERR(info->rtc_src_clk)) {
ret = dev_err_probe(&pdev->dev, PTR_ERR(info->rtc_src_clk),
"failed to find rtc source clock\n");
goto err_src_clk;
}
ret = clk_prepare_enable(info->rtc_src_clk);
if (ret)
goto err_src_clk;
}
/* disable RTC enable bits potentially set by the bootloader */
if (info->data->disable)
info->data->disable(info);
/* check to see if everything is setup correctly */
if (info->data->enable)
info->data->enable(info);
dev_dbg(&pdev->dev, "s3c2410_rtc: RTCCON=%02x\n",
readw(info->base + S3C2410_RTCCON));
device_init_wakeup(&pdev->dev, 1);
info->rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(info->rtc)) {
ret = PTR_ERR(info->rtc);
goto err_nortc;
}
info->rtc->ops = &s3c_rtcops;
info->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
info->rtc->range_max = RTC_TIMESTAMP_END_2099;
ret = devm_rtc_register_device(info->rtc);
if (ret)
goto err_nortc;
ret = devm_request_irq(&pdev->dev, info->irq_alarm, s3c_rtc_alarmirq,
0, "s3c2410-rtc alarm", info);
if (ret) {
dev_err(&pdev->dev, "IRQ%d error %d\n", info->irq_alarm, ret);
goto err_nortc;
}
s3c_rtc_disable_clk(info);
return 0;
err_nortc:
if (info->data->disable)
info->data->disable(info);
if (info->data->needs_src_clk)
clk_disable_unprepare(info->rtc_src_clk);
err_src_clk:
clk_disable_unprepare(info->rtc_clk);
return ret;
}
#ifdef CONFIG_PM_SLEEP
static int s3c_rtc_suspend(struct device *dev)
{
struct s3c_rtc *info = dev_get_drvdata(dev);
int ret;
ret = s3c_rtc_enable_clk(info);
if (ret)
return ret;
if (info->data->disable)
info->data->disable(info);
if (device_may_wakeup(dev) && !info->wake_en) {
if (enable_irq_wake(info->irq_alarm) == 0)
info->wake_en = true;
else
dev_err(dev, "enable_irq_wake failed\n");
}
return 0;
}
static int s3c_rtc_resume(struct device *dev)
{
struct s3c_rtc *info = dev_get_drvdata(dev);
if (info->data->enable)
info->data->enable(info);
s3c_rtc_disable_clk(info);
if (device_may_wakeup(dev) && info->wake_en) {
disable_irq_wake(info->irq_alarm);
info->wake_en = false;
}
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(s3c_rtc_pm_ops, s3c_rtc_suspend, s3c_rtc_resume);
static void s3c24xx_rtc_irq(struct s3c_rtc *info, int mask)
{
rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF);
}
static void s3c6410_rtc_irq(struct s3c_rtc *info, int mask)
{
rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF);
writeb(mask, info->base + S3C2410_INTP);
}
static struct s3c_rtc_data const s3c2410_rtc_data = {
.irq_handler = s3c24xx_rtc_irq,
.enable = s3c24xx_rtc_enable,
.disable = s3c24xx_rtc_disable,
};
static struct s3c_rtc_data const s3c2416_rtc_data = {
.irq_handler = s3c24xx_rtc_irq,
.enable = s3c24xx_rtc_enable,
.disable = s3c24xx_rtc_disable,
};
static struct s3c_rtc_data const s3c2443_rtc_data = {
.irq_handler = s3c24xx_rtc_irq,
.enable = s3c24xx_rtc_enable,
.disable = s3c24xx_rtc_disable,
};
static struct s3c_rtc_data const s3c6410_rtc_data = {
.needs_src_clk = true,
.irq_handler = s3c6410_rtc_irq,
.enable = s3c24xx_rtc_enable,
.disable = s3c6410_rtc_disable,
};
static const __maybe_unused struct of_device_id s3c_rtc_dt_match[] = {
{
.compatible = "samsung,s3c2410-rtc",
.data = &s3c2410_rtc_data,
}, {
.compatible = "samsung,s3c2416-rtc",
.data = &s3c2416_rtc_data,
}, {
.compatible = "samsung,s3c2443-rtc",
.data = &s3c2443_rtc_data,
}, {
.compatible = "samsung,s3c6410-rtc",
.data = &s3c6410_rtc_data,
}, {
.compatible = "samsung,exynos3250-rtc",
.data = &s3c6410_rtc_data,
},
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, s3c_rtc_dt_match);
static struct platform_driver s3c_rtc_driver = {
.probe = s3c_rtc_probe,
.remove = s3c_rtc_remove,
.driver = {
.name = "s3c-rtc",
.pm = &s3c_rtc_pm_ops,
.of_match_table = of_match_ptr(s3c_rtc_dt_match),
},
};
module_platform_driver(s3c_rtc_driver);
MODULE_DESCRIPTION("Samsung S3C RTC Driver");
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:s3c2410-rtc");