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linux/drivers/rtc/rtc-mv.c
Uwe Kleine-König ede66fb37f rtc: mv: Convert to platform remove callback returning void 
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231002080529.2535610-11-u.kleine-koenig@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2023-10-13 12:29:08 +02:00

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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,
.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);
else
clear_bit(RTC_FEATURE_ALARM, pdata->rtc->features);
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 void __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);
}
#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
/*
* mv_rtc_remove() lives in .exit.text. For drivers registered via
* module_platform_driver_probe() this is ok because they cannot get unbound at
* runtime. So mark the driver struct with __refdata to prevent modpost
* triggering a section mismatch warning.
*/
static struct platform_driver mv_rtc_driver __refdata = {
.remove_new = __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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