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linux/drivers/rtc/rtc-mv.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
/*
* Driver for the RTC in Marvell SoCs.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/gfp.h>
#include <linux/module.h>
#define RTC_TIME_REG_OFFS 0
#define RTC_SECONDS_OFFS 0
#define RTC_MINUTES_OFFS 8
#define RTC_HOURS_OFFS 16
#define RTC_WDAY_OFFS 24
#define RTC_HOURS_12H_MODE BIT(22) /* 12 hour mode */
#define RTC_DATE_REG_OFFS 4
#define RTC_MDAY_OFFS 0
#define RTC_MONTH_OFFS 8
#define RTC_YEAR_OFFS 16
#define RTC_ALARM_TIME_REG_OFFS 8
#define RTC_ALARM_DATE_REG_OFFS 0xc
#define RTC_ALARM_VALID BIT(7)
#define RTC_ALARM_INTERRUPT_MASK_REG_OFFS 0x10
#define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS 0x14
struct rtc_plat_data {
struct rtc_device *rtc;
void __iomem *ioaddr;
int irq;
struct clk *clk;
};
static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct rtc_plat_data *pdata = dev_get_drvdata(dev);
void __iomem *ioaddr = pdata->ioaddr;
u32 rtc_reg;
rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
(bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
(bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
(bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
(bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
(bin2bcd(tm->tm_year - 100) << RTC_YEAR_OFFS);
writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
return 0;
}
static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct rtc_plat_data *pdata = dev_get_drvdata(dev);
void __iomem *ioaddr = pdata->ioaddr;
u32 rtc_time, rtc_date;
unsigned int year, month, day, hour, minute, second, wday;
rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
second = rtc_time & 0x7f;
minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
day = rtc_date & 0x3f;
month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
tm->tm_sec = bcd2bin(second);
tm->tm_min = bcd2bin(minute);
tm->tm_hour = bcd2bin(hour);
tm->tm_mday = bcd2bin(day);
tm->tm_wday = bcd2bin(wday);
tm->tm_mon = bcd2bin(month) - 1;
/* hw counts from year 2000, but tm_year is relative to 1900 */
tm->tm_year = bcd2bin(year) + 100;
return 0;
}
static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
struct rtc_plat_data *pdata = dev_get_drvdata(dev);
void __iomem *ioaddr = pdata->ioaddr;
u32 rtc_time, rtc_date;
unsigned int year, month, day, hour, minute, second, wday;
rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS);
rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS);
second = rtc_time & 0x7f;
minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
day = rtc_date & 0x3f;
month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
alm->time.tm_sec = bcd2bin(second);
alm->time.tm_min = bcd2bin(minute);
alm->time.tm_hour = bcd2bin(hour);
alm->time.tm_mday = bcd2bin(day);
alm->time.tm_wday = bcd2bin(wday);
alm->time.tm_mon = bcd2bin(month) - 1;
/* hw counts from year 2000, but tm_year is relative to 1900 */
alm->time.tm_year = bcd2bin(year) + 100;
alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
return rtc_valid_tm(&alm->time);
}
static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
struct rtc_plat_data *pdata = dev_get_drvdata(dev);
void __iomem *ioaddr = pdata->ioaddr;
u32 rtc_reg = 0;
if (alm->time.tm_sec >= 0)
rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
<< RTC_SECONDS_OFFS;
if (alm->time.tm_min >= 0)
rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
<< RTC_MINUTES_OFFS;
if (alm->time.tm_hour >= 0)
rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
<< RTC_HOURS_OFFS;
writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
if (alm->time.tm_mday >= 0)
rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
<< RTC_MDAY_OFFS;
else
rtc_reg = 0;
if (alm->time.tm_mon >= 0)
rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
<< RTC_MONTH_OFFS;
if (alm->time.tm_year >= 0)
rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year - 100))
<< RTC_YEAR_OFFS;
writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
writel(alm->enabled ? 1 : 0,
ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
return 0;
}
static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct rtc_plat_data *pdata = dev_get_drvdata(dev);
void __iomem *ioaddr = pdata->ioaddr;
if (pdata->irq < 0)
return -EINVAL; /* fall back into rtc-dev's emulation */
if (enabled)
writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
else
writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
return 0;
}
static irqreturn_t mv_rtc_interrupt(int irq, void *data)
{
struct rtc_plat_data *pdata = data;
void __iomem *ioaddr = pdata->ioaddr;
/* alarm irq? */
if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
return IRQ_NONE;
/* clear interrupt */
writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
return IRQ_HANDLED;
}
static const struct rtc_class_ops mv_rtc_ops = {
.read_time = mv_rtc_read_time,
.set_time = mv_rtc_set_time,
};
static const struct rtc_class_ops mv_rtc_alarm_ops = {
.read_time = mv_rtc_read_time,
.set_time = mv_rtc_set_time,
.read_alarm = mv_rtc_read_alarm,
.set_alarm = mv_rtc_set_alarm,
.alarm_irq_enable = mv_rtc_alarm_irq_enable,
};
static int __init mv_rtc_probe(struct platform_device *pdev)
{
struct rtc_plat_data *pdata;
u32 rtc_time;
int ret = 0;
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return -ENOMEM;
pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(pdata->ioaddr))
return PTR_ERR(pdata->ioaddr);
pdata->clk = devm_clk_get(&pdev->dev, NULL);
/* Not all SoCs require a clock.*/
if (!IS_ERR(pdata->clk))
clk_prepare_enable(pdata->clk);
/* make sure the 24 hour mode is enabled */
rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
if (rtc_time & RTC_HOURS_12H_MODE) {
dev_err(&pdev->dev, "12 Hour mode is enabled but not supported.\n");
ret = -EINVAL;
goto out;
}
/* make sure it is actually functional */
if (rtc_time == 0x01000000) {
ssleep(1);
rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
if (rtc_time == 0x01000000) {
dev_err(&pdev->dev, "internal RTC not ticking\n");
ret = -ENODEV;
goto out;
}
}
pdata->irq = platform_get_irq(pdev, 0);
platform_set_drvdata(pdev, pdata);
pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(pdata->rtc)) {
ret = PTR_ERR(pdata->rtc);
goto out;
}
if (pdata->irq >= 0) {
writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
IRQF_SHARED,
pdev->name, pdata) < 0) {
dev_warn(&pdev->dev, "interrupt not available.\n");
pdata->irq = -1;
}
}
if (pdata->irq >= 0) {
device_init_wakeup(&pdev->dev, 1);
pdata->rtc->ops = &mv_rtc_alarm_ops;
} else {
pdata->rtc->ops = &mv_rtc_ops;
}
pdata->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
pdata->rtc->range_max = RTC_TIMESTAMP_END_2099;
ret = devm_rtc_register_device(pdata->rtc);
if (!ret)
return 0;
out:
if (!IS_ERR(pdata->clk))
clk_disable_unprepare(pdata->clk);
return ret;
}
static int __exit mv_rtc_remove(struct platform_device *pdev)
{
struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
if (pdata->irq >= 0)
device_init_wakeup(&pdev->dev, 0);
if (!IS_ERR(pdata->clk))
clk_disable_unprepare(pdata->clk);
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id rtc_mv_of_match_table[] = {
{ .compatible = "marvell,orion-rtc", },
{}
};
MODULE_DEVICE_TABLE(of, rtc_mv_of_match_table);
#endif
static struct platform_driver mv_rtc_driver = {
.remove = __exit_p(mv_rtc_remove),
.driver = {
.name = "rtc-mv",
.of_match_table = of_match_ptr(rtc_mv_of_match_table),
},
};
module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe);
MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
MODULE_DESCRIPTION("Marvell RTC driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:rtc-mv");
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