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linux/drivers/rtc/rtc-lpc24xx.c
Uwe Kleine-König 52fcb90d8c rtc: lpc24xx: 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 (mostly) ignored
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.

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/20230304133028.2135435-15-u.kleine-koenig@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2023-03-17 23:03:17 +01:00

300 lines
8.0 KiB
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* RTC driver for NXP LPC178x/18xx/43xx Real-Time Clock (RTC)
*
* Copyright (C) 2011 NXP Semiconductors
* Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
*/
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
/* LPC24xx RTC register offsets and bits */
#define LPC24XX_ILR 0x00
#define LPC24XX_RTCCIF BIT(0)
#define LPC24XX_RTCALF BIT(1)
#define LPC24XX_CTC 0x04
#define LPC24XX_CCR 0x08
#define LPC24XX_CLKEN BIT(0)
#define LPC178X_CCALEN BIT(4)
#define LPC24XX_CIIR 0x0c
#define LPC24XX_AMR 0x10
#define LPC24XX_ALARM_DISABLE 0xff
#define LPC24XX_CTIME0 0x14
#define LPC24XX_CTIME1 0x18
#define LPC24XX_CTIME2 0x1c
#define LPC24XX_SEC 0x20
#define LPC24XX_MIN 0x24
#define LPC24XX_HOUR 0x28
#define LPC24XX_DOM 0x2c
#define LPC24XX_DOW 0x30
#define LPC24XX_DOY 0x34
#define LPC24XX_MONTH 0x38
#define LPC24XX_YEAR 0x3c
#define LPC24XX_ALSEC 0x60
#define LPC24XX_ALMIN 0x64
#define LPC24XX_ALHOUR 0x68
#define LPC24XX_ALDOM 0x6c
#define LPC24XX_ALDOW 0x70
#define LPC24XX_ALDOY 0x74
#define LPC24XX_ALMON 0x78
#define LPC24XX_ALYEAR 0x7c
/* Macros to read fields in consolidated time (CT) registers */
#define CT0_SECS(x) (((x) >> 0) & 0x3f)
#define CT0_MINS(x) (((x) >> 8) & 0x3f)
#define CT0_HOURS(x) (((x) >> 16) & 0x1f)
#define CT0_DOW(x) (((x) >> 24) & 0x07)
#define CT1_DOM(x) (((x) >> 0) & 0x1f)
#define CT1_MONTH(x) (((x) >> 8) & 0x0f)
#define CT1_YEAR(x) (((x) >> 16) & 0xfff)
#define CT2_DOY(x) (((x) >> 0) & 0xfff)
#define rtc_readl(dev, reg) readl((dev)->rtc_base + (reg))
#define rtc_writel(dev, reg, val) writel((val), (dev)->rtc_base + (reg))
struct lpc24xx_rtc {
void __iomem *rtc_base;
struct rtc_device *rtc;
struct clk *clk_rtc;
struct clk *clk_reg;
};
static int lpc24xx_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct lpc24xx_rtc *rtc = dev_get_drvdata(dev);
/* Disable RTC during update */
rtc_writel(rtc, LPC24XX_CCR, LPC178X_CCALEN);
rtc_writel(rtc, LPC24XX_SEC, tm->tm_sec);
rtc_writel(rtc, LPC24XX_MIN, tm->tm_min);
rtc_writel(rtc, LPC24XX_HOUR, tm->tm_hour);
rtc_writel(rtc, LPC24XX_DOW, tm->tm_wday);
rtc_writel(rtc, LPC24XX_DOM, tm->tm_mday);
rtc_writel(rtc, LPC24XX_DOY, tm->tm_yday);
rtc_writel(rtc, LPC24XX_MONTH, tm->tm_mon);
rtc_writel(rtc, LPC24XX_YEAR, tm->tm_year);
rtc_writel(rtc, LPC24XX_CCR, LPC24XX_CLKEN | LPC178X_CCALEN);
return 0;
}
static int lpc24xx_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct lpc24xx_rtc *rtc = dev_get_drvdata(dev);
u32 ct0, ct1, ct2;
ct0 = rtc_readl(rtc, LPC24XX_CTIME0);
ct1 = rtc_readl(rtc, LPC24XX_CTIME1);
ct2 = rtc_readl(rtc, LPC24XX_CTIME2);
tm->tm_sec = CT0_SECS(ct0);
tm->tm_min = CT0_MINS(ct0);
tm->tm_hour = CT0_HOURS(ct0);
tm->tm_wday = CT0_DOW(ct0);
tm->tm_mon = CT1_MONTH(ct1);
tm->tm_mday = CT1_DOM(ct1);
tm->tm_year = CT1_YEAR(ct1);
tm->tm_yday = CT2_DOY(ct2);
return 0;
}
static int lpc24xx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
struct lpc24xx_rtc *rtc = dev_get_drvdata(dev);
struct rtc_time *tm = &wkalrm->time;
tm->tm_sec = rtc_readl(rtc, LPC24XX_ALSEC);
tm->tm_min = rtc_readl(rtc, LPC24XX_ALMIN);
tm->tm_hour = rtc_readl(rtc, LPC24XX_ALHOUR);
tm->tm_mday = rtc_readl(rtc, LPC24XX_ALDOM);
tm->tm_wday = rtc_readl(rtc, LPC24XX_ALDOW);
tm->tm_yday = rtc_readl(rtc, LPC24XX_ALDOY);
tm->tm_mon = rtc_readl(rtc, LPC24XX_ALMON);
tm->tm_year = rtc_readl(rtc, LPC24XX_ALYEAR);
wkalrm->enabled = rtc_readl(rtc, LPC24XX_AMR) == 0;
wkalrm->pending = !!(rtc_readl(rtc, LPC24XX_ILR) & LPC24XX_RTCCIF);
return rtc_valid_tm(&wkalrm->time);
}
static int lpc24xx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
struct lpc24xx_rtc *rtc = dev_get_drvdata(dev);
struct rtc_time *tm = &wkalrm->time;
/* Disable alarm irq during update */
rtc_writel(rtc, LPC24XX_AMR, LPC24XX_ALARM_DISABLE);
rtc_writel(rtc, LPC24XX_ALSEC, tm->tm_sec);
rtc_writel(rtc, LPC24XX_ALMIN, tm->tm_min);
rtc_writel(rtc, LPC24XX_ALHOUR, tm->tm_hour);
rtc_writel(rtc, LPC24XX_ALDOM, tm->tm_mday);
rtc_writel(rtc, LPC24XX_ALDOW, tm->tm_wday);
rtc_writel(rtc, LPC24XX_ALDOY, tm->tm_yday);
rtc_writel(rtc, LPC24XX_ALMON, tm->tm_mon);
rtc_writel(rtc, LPC24XX_ALYEAR, tm->tm_year);
if (wkalrm->enabled)
rtc_writel(rtc, LPC24XX_AMR, 0);
return 0;
}
static int lpc24xx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
{
struct lpc24xx_rtc *rtc = dev_get_drvdata(dev);
if (enable)
rtc_writel(rtc, LPC24XX_AMR, 0);
else
rtc_writel(rtc, LPC24XX_AMR, LPC24XX_ALARM_DISABLE);
return 0;
}
static irqreturn_t lpc24xx_rtc_interrupt(int irq, void *data)
{
unsigned long events = RTC_IRQF;
struct lpc24xx_rtc *rtc = data;
u32 rtc_iir;
/* Check interrupt cause */
rtc_iir = rtc_readl(rtc, LPC24XX_ILR);
if (rtc_iir & LPC24XX_RTCALF) {
events |= RTC_AF;
rtc_writel(rtc, LPC24XX_AMR, LPC24XX_ALARM_DISABLE);
}
/* Clear interrupt status and report event */
rtc_writel(rtc, LPC24XX_ILR, rtc_iir);
rtc_update_irq(rtc->rtc, 1, events);
return IRQ_HANDLED;
}
static const struct rtc_class_ops lpc24xx_rtc_ops = {
.read_time = lpc24xx_rtc_read_time,
.set_time = lpc24xx_rtc_set_time,
.read_alarm = lpc24xx_rtc_read_alarm,
.set_alarm = lpc24xx_rtc_set_alarm,
.alarm_irq_enable = lpc24xx_rtc_alarm_irq_enable,
};
static int lpc24xx_rtc_probe(struct platform_device *pdev)
{
struct lpc24xx_rtc *rtc;
int irq, ret;
rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
if (!rtc)
return -ENOMEM;
rtc->rtc_base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(rtc->rtc_base))
return PTR_ERR(rtc->rtc_base);
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
rtc->clk_rtc = devm_clk_get(&pdev->dev, "rtc");
if (IS_ERR(rtc->clk_rtc)) {
dev_err(&pdev->dev, "error getting rtc clock\n");
return PTR_ERR(rtc->clk_rtc);
}
rtc->clk_reg = devm_clk_get(&pdev->dev, "reg");
if (IS_ERR(rtc->clk_reg)) {
dev_err(&pdev->dev, "error getting reg clock\n");
return PTR_ERR(rtc->clk_reg);
}
ret = clk_prepare_enable(rtc->clk_rtc);
if (ret) {
dev_err(&pdev->dev, "unable to enable rtc clock\n");
return ret;
}
ret = clk_prepare_enable(rtc->clk_reg);
if (ret) {
dev_err(&pdev->dev, "unable to enable reg clock\n");
goto disable_rtc_clk;
}
platform_set_drvdata(pdev, rtc);
/* Clear any pending interrupts */
rtc_writel(rtc, LPC24XX_ILR, LPC24XX_RTCCIF | LPC24XX_RTCALF);
/* Enable RTC count */
rtc_writel(rtc, LPC24XX_CCR, LPC24XX_CLKEN | LPC178X_CCALEN);
ret = devm_request_irq(&pdev->dev, irq, lpc24xx_rtc_interrupt, 0,
pdev->name, rtc);
if (ret < 0) {
dev_warn(&pdev->dev, "can't request interrupt\n");
goto disable_clks;
}
rtc->rtc = devm_rtc_device_register(&pdev->dev, "lpc24xx-rtc",
&lpc24xx_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc->rtc)) {
dev_err(&pdev->dev, "can't register rtc device\n");
ret = PTR_ERR(rtc->rtc);
goto disable_clks;
}
return 0;
disable_clks:
clk_disable_unprepare(rtc->clk_reg);
disable_rtc_clk:
clk_disable_unprepare(rtc->clk_rtc);
return ret;
}
static void lpc24xx_rtc_remove(struct platform_device *pdev)
{
struct lpc24xx_rtc *rtc = platform_get_drvdata(pdev);
/* Ensure all interrupt sources are masked */
rtc_writel(rtc, LPC24XX_AMR, LPC24XX_ALARM_DISABLE);
rtc_writel(rtc, LPC24XX_CIIR, 0);
rtc_writel(rtc, LPC24XX_CCR, LPC178X_CCALEN);
clk_disable_unprepare(rtc->clk_rtc);
clk_disable_unprepare(rtc->clk_reg);
}
static const struct of_device_id lpc24xx_rtc_match[] = {
{ .compatible = "nxp,lpc1788-rtc" },
{ }
};
MODULE_DEVICE_TABLE(of, lpc24xx_rtc_match);
static struct platform_driver lpc24xx_rtc_driver = {
.probe = lpc24xx_rtc_probe,
.remove_new = lpc24xx_rtc_remove,
.driver = {
.name = "lpc24xx-rtc",
.of_match_table = lpc24xx_rtc_match,
},
};
module_platform_driver(lpc24xx_rtc_driver);
MODULE_AUTHOR("Kevin Wells <wellsk40@gmail.com>");
MODULE_DESCRIPTION("RTC driver for the LPC178x/18xx/408x/43xx SoCs");
MODULE_LICENSE("GPL");
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