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linux/drivers/rtc/rtc-davinci.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-or-later
/*
* DaVinci Power Management and Real Time Clock Driver for TI platforms
*
* Copyright (C) 2009 Texas Instruments, Inc
*
* Author: Miguel Aguilar <miguel.aguilar@ridgerun.com>
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/slab.h>
/*
* The DaVinci RTC is a simple RTC with the following
* Sec: 0 - 59 : BCD count
* Min: 0 - 59 : BCD count
* Hour: 0 - 23 : BCD count
* Day: 0 - 0x7FFF(32767) : Binary count ( Over 89 years )
*/
/* PRTC interface registers */
#define DAVINCI_PRTCIF_PID 0x00
#define PRTCIF_CTLR 0x04
#define PRTCIF_LDATA 0x08
#define PRTCIF_UDATA 0x0C
#define PRTCIF_INTEN 0x10
#define PRTCIF_INTFLG 0x14
/* PRTCIF_CTLR bit fields */
#define PRTCIF_CTLR_BUSY BIT(31)
#define PRTCIF_CTLR_SIZE BIT(25)
#define PRTCIF_CTLR_DIR BIT(24)
#define PRTCIF_CTLR_BENU_MSB BIT(23)
#define PRTCIF_CTLR_BENU_3RD_BYTE BIT(22)
#define PRTCIF_CTLR_BENU_2ND_BYTE BIT(21)
#define PRTCIF_CTLR_BENU_LSB BIT(20)
#define PRTCIF_CTLR_BENU_MASK (0x00F00000)
#define PRTCIF_CTLR_BENL_MSB BIT(19)
#define PRTCIF_CTLR_BENL_3RD_BYTE BIT(18)
#define PRTCIF_CTLR_BENL_2ND_BYTE BIT(17)
#define PRTCIF_CTLR_BENL_LSB BIT(16)
#define PRTCIF_CTLR_BENL_MASK (0x000F0000)
/* PRTCIF_INTEN bit fields */
#define PRTCIF_INTEN_RTCSS BIT(1)
#define PRTCIF_INTEN_RTCIF BIT(0)
#define PRTCIF_INTEN_MASK (PRTCIF_INTEN_RTCSS \
| PRTCIF_INTEN_RTCIF)
/* PRTCIF_INTFLG bit fields */
#define PRTCIF_INTFLG_RTCSS BIT(1)
#define PRTCIF_INTFLG_RTCIF BIT(0)
#define PRTCIF_INTFLG_MASK (PRTCIF_INTFLG_RTCSS \
| PRTCIF_INTFLG_RTCIF)
/* PRTC subsystem registers */
#define PRTCSS_RTC_INTC_EXTENA1 (0x0C)
#define PRTCSS_RTC_CTRL (0x10)
#define PRTCSS_RTC_WDT (0x11)
#define PRTCSS_RTC_TMR0 (0x12)
#define PRTCSS_RTC_TMR1 (0x13)
#define PRTCSS_RTC_CCTRL (0x14)
#define PRTCSS_RTC_SEC (0x15)
#define PRTCSS_RTC_MIN (0x16)
#define PRTCSS_RTC_HOUR (0x17)
#define PRTCSS_RTC_DAY0 (0x18)
#define PRTCSS_RTC_DAY1 (0x19)
#define PRTCSS_RTC_AMIN (0x1A)
#define PRTCSS_RTC_AHOUR (0x1B)
#define PRTCSS_RTC_ADAY0 (0x1C)
#define PRTCSS_RTC_ADAY1 (0x1D)
#define PRTCSS_RTC_CLKC_CNT (0x20)
/* PRTCSS_RTC_INTC_EXTENA1 */
#define PRTCSS_RTC_INTC_EXTENA1_MASK (0x07)
/* PRTCSS_RTC_CTRL bit fields */
#define PRTCSS_RTC_CTRL_WDTBUS BIT(7)
#define PRTCSS_RTC_CTRL_WEN BIT(6)
#define PRTCSS_RTC_CTRL_WDRT BIT(5)
#define PRTCSS_RTC_CTRL_WDTFLG BIT(4)
#define PRTCSS_RTC_CTRL_TE BIT(3)
#define PRTCSS_RTC_CTRL_TIEN BIT(2)
#define PRTCSS_RTC_CTRL_TMRFLG BIT(1)
#define PRTCSS_RTC_CTRL_TMMD BIT(0)
/* PRTCSS_RTC_CCTRL bit fields */
#define PRTCSS_RTC_CCTRL_CALBUSY BIT(7)
#define PRTCSS_RTC_CCTRL_DAEN BIT(5)
#define PRTCSS_RTC_CCTRL_HAEN BIT(4)
#define PRTCSS_RTC_CCTRL_MAEN BIT(3)
#define PRTCSS_RTC_CCTRL_ALMFLG BIT(2)
#define PRTCSS_RTC_CCTRL_AIEN BIT(1)
#define PRTCSS_RTC_CCTRL_CAEN BIT(0)
static DEFINE_SPINLOCK(davinci_rtc_lock);
struct davinci_rtc {
struct rtc_device *rtc;
void __iomem *base;
int irq;
};
static inline void rtcif_write(struct davinci_rtc *davinci_rtc,
u32 val, u32 addr)
{
writel(val, davinci_rtc->base + addr);
}
static inline u32 rtcif_read(struct davinci_rtc *davinci_rtc, u32 addr)
{
return readl(davinci_rtc->base + addr);
}
static inline void rtcif_wait(struct davinci_rtc *davinci_rtc)
{
while (rtcif_read(davinci_rtc, PRTCIF_CTLR) & PRTCIF_CTLR_BUSY)
cpu_relax();
}
static inline void rtcss_write(struct davinci_rtc *davinci_rtc,
unsigned long val, u8 addr)
{
rtcif_wait(davinci_rtc);
rtcif_write(davinci_rtc, PRTCIF_CTLR_BENL_LSB | addr, PRTCIF_CTLR);
rtcif_write(davinci_rtc, val, PRTCIF_LDATA);
rtcif_wait(davinci_rtc);
}
static inline u8 rtcss_read(struct davinci_rtc *davinci_rtc, u8 addr)
{
rtcif_wait(davinci_rtc);
rtcif_write(davinci_rtc, PRTCIF_CTLR_DIR | PRTCIF_CTLR_BENL_LSB | addr,
PRTCIF_CTLR);
rtcif_wait(davinci_rtc);
return rtcif_read(davinci_rtc, PRTCIF_LDATA);
}
static inline void davinci_rtcss_calendar_wait(struct davinci_rtc *davinci_rtc)
{
while (rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL) &
PRTCSS_RTC_CCTRL_CALBUSY)
cpu_relax();
}
static irqreturn_t davinci_rtc_interrupt(int irq, void *class_dev)
{
struct davinci_rtc *davinci_rtc = class_dev;
unsigned long events = 0;
u32 irq_flg;
u8 alm_irq, tmr_irq;
u8 rtc_ctrl, rtc_cctrl;
int ret = IRQ_NONE;
irq_flg = rtcif_read(davinci_rtc, PRTCIF_INTFLG) &
PRTCIF_INTFLG_RTCSS;
alm_irq = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL) &
PRTCSS_RTC_CCTRL_ALMFLG;
tmr_irq = rtcss_read(davinci_rtc, PRTCSS_RTC_CTRL) &
PRTCSS_RTC_CTRL_TMRFLG;
if (irq_flg) {
if (alm_irq) {
events |= RTC_IRQF | RTC_AF;
rtc_cctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL);
rtc_cctrl |= PRTCSS_RTC_CCTRL_ALMFLG;
rtcss_write(davinci_rtc, rtc_cctrl, PRTCSS_RTC_CCTRL);
} else if (tmr_irq) {
events |= RTC_IRQF | RTC_PF;
rtc_ctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CTRL);
rtc_ctrl |= PRTCSS_RTC_CTRL_TMRFLG;
rtcss_write(davinci_rtc, rtc_ctrl, PRTCSS_RTC_CTRL);
}
rtcif_write(davinci_rtc, PRTCIF_INTFLG_RTCSS,
PRTCIF_INTFLG);
rtc_update_irq(davinci_rtc->rtc, 1, events);
ret = IRQ_HANDLED;
}
return ret;
}
static int
davinci_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
u8 rtc_ctrl;
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&davinci_rtc_lock, flags);
rtc_ctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CTRL);
switch (cmd) {
case RTC_WIE_ON:
rtc_ctrl |= PRTCSS_RTC_CTRL_WEN | PRTCSS_RTC_CTRL_WDTFLG;
break;
case RTC_WIE_OFF:
rtc_ctrl &= ~PRTCSS_RTC_CTRL_WEN;
break;
default:
ret = -ENOIOCTLCMD;
}
rtcss_write(davinci_rtc, rtc_ctrl, PRTCSS_RTC_CTRL);
spin_unlock_irqrestore(&davinci_rtc_lock, flags);
return ret;
}
static void convertfromdays(u16 days, struct rtc_time *tm)
{
int tmp_days, year, mon;
for (year = 2000;; year++) {
tmp_days = rtc_year_days(1, 12, year);
if (days >= tmp_days)
days -= tmp_days;
else {
for (mon = 0;; mon++) {
tmp_days = rtc_month_days(mon, year);
if (days >= tmp_days) {
days -= tmp_days;
} else {
tm->tm_year = year - 1900;
tm->tm_mon = mon;
tm->tm_mday = days + 1;
break;
}
}
break;
}
}
}
static void convert2days(u16 *days, struct rtc_time *tm)
{
int i;
*days = 0;
for (i = 2000; i < 1900 + tm->tm_year; i++)
*days += rtc_year_days(1, 12, i);
*days += rtc_year_days(tm->tm_mday, tm->tm_mon, 1900 + tm->tm_year);
}
static int davinci_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
u16 days = 0;
u8 day0, day1;
unsigned long flags;
spin_lock_irqsave(&davinci_rtc_lock, flags);
davinci_rtcss_calendar_wait(davinci_rtc);
tm->tm_sec = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_SEC));
davinci_rtcss_calendar_wait(davinci_rtc);
tm->tm_min = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_MIN));
davinci_rtcss_calendar_wait(davinci_rtc);
tm->tm_hour = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_HOUR));
davinci_rtcss_calendar_wait(davinci_rtc);
day0 = rtcss_read(davinci_rtc, PRTCSS_RTC_DAY0);
davinci_rtcss_calendar_wait(davinci_rtc);
day1 = rtcss_read(davinci_rtc, PRTCSS_RTC_DAY1);
spin_unlock_irqrestore(&davinci_rtc_lock, flags);
days |= day1;
days <<= 8;
days |= day0;
convertfromdays(days, tm);
return 0;
}
static int davinci_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
u16 days;
u8 rtc_cctrl;
unsigned long flags;
convert2days(&days, tm);
spin_lock_irqsave(&davinci_rtc_lock, flags);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, bin2bcd(tm->tm_sec), PRTCSS_RTC_SEC);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, bin2bcd(tm->tm_min), PRTCSS_RTC_MIN);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, bin2bcd(tm->tm_hour), PRTCSS_RTC_HOUR);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, days & 0xFF, PRTCSS_RTC_DAY0);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, (days & 0xFF00) >> 8, PRTCSS_RTC_DAY1);
rtc_cctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL);
rtc_cctrl |= PRTCSS_RTC_CCTRL_CAEN;
rtcss_write(davinci_rtc, rtc_cctrl, PRTCSS_RTC_CCTRL);
spin_unlock_irqrestore(&davinci_rtc_lock, flags);
return 0;
}
static int davinci_rtc_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
unsigned long flags;
u8 rtc_cctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL);
spin_lock_irqsave(&davinci_rtc_lock, flags);
if (enabled)
rtc_cctrl |= PRTCSS_RTC_CCTRL_DAEN |
PRTCSS_RTC_CCTRL_HAEN |
PRTCSS_RTC_CCTRL_MAEN |
PRTCSS_RTC_CCTRL_ALMFLG |
PRTCSS_RTC_CCTRL_AIEN;
else
rtc_cctrl &= ~PRTCSS_RTC_CCTRL_AIEN;
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, rtc_cctrl, PRTCSS_RTC_CCTRL);
spin_unlock_irqrestore(&davinci_rtc_lock, flags);
return 0;
}
static int davinci_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
u16 days = 0;
u8 day0, day1;
unsigned long flags;
alm->time.tm_sec = 0;
spin_lock_irqsave(&davinci_rtc_lock, flags);
davinci_rtcss_calendar_wait(davinci_rtc);
alm->time.tm_min = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_AMIN));
davinci_rtcss_calendar_wait(davinci_rtc);
alm->time.tm_hour = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_AHOUR));
davinci_rtcss_calendar_wait(davinci_rtc);
day0 = rtcss_read(davinci_rtc, PRTCSS_RTC_ADAY0);
davinci_rtcss_calendar_wait(davinci_rtc);
day1 = rtcss_read(davinci_rtc, PRTCSS_RTC_ADAY1);
spin_unlock_irqrestore(&davinci_rtc_lock, flags);
days |= day1;
days <<= 8;
days |= day0;
convertfromdays(days, &alm->time);
alm->pending = !!(rtcss_read(davinci_rtc,
PRTCSS_RTC_CCTRL) &
PRTCSS_RTC_CCTRL_AIEN);
alm->enabled = alm->pending && device_may_wakeup(dev);
return 0;
}
static int davinci_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
unsigned long flags;
u16 days;
convert2days(&days, &alm->time);
spin_lock_irqsave(&davinci_rtc_lock, flags);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, bin2bcd(alm->time.tm_min), PRTCSS_RTC_AMIN);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, bin2bcd(alm->time.tm_hour), PRTCSS_RTC_AHOUR);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, days & 0xFF, PRTCSS_RTC_ADAY0);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, (days & 0xFF00) >> 8, PRTCSS_RTC_ADAY1);
spin_unlock_irqrestore(&davinci_rtc_lock, flags);
return 0;
}
static const struct rtc_class_ops davinci_rtc_ops = {
.ioctl = davinci_rtc_ioctl,
.read_time = davinci_rtc_read_time,
.set_time = davinci_rtc_set_time,
.alarm_irq_enable = davinci_rtc_alarm_irq_enable,
.read_alarm = davinci_rtc_read_alarm,
.set_alarm = davinci_rtc_set_alarm,
};
static int __init davinci_rtc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct davinci_rtc *davinci_rtc;
int ret = 0;
davinci_rtc = devm_kzalloc(&pdev->dev, sizeof(struct davinci_rtc), GFP_KERNEL);
if (!davinci_rtc)
return -ENOMEM;
davinci_rtc->irq = platform_get_irq(pdev, 0);
if (davinci_rtc->irq < 0)
return davinci_rtc->irq;
davinci_rtc->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(davinci_rtc->base))
return PTR_ERR(davinci_rtc->base);
platform_set_drvdata(pdev, davinci_rtc);
davinci_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(davinci_rtc->rtc))
return PTR_ERR(davinci_rtc->rtc);
davinci_rtc->rtc->ops = &davinci_rtc_ops;
davinci_rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
davinci_rtc->rtc->range_max = RTC_TIMESTAMP_BEGIN_2000 + (1 << 16) * 86400ULL - 1;
rtcif_write(davinci_rtc, PRTCIF_INTFLG_RTCSS, PRTCIF_INTFLG);
rtcif_write(davinci_rtc, 0, PRTCIF_INTEN);
rtcss_write(davinci_rtc, 0, PRTCSS_RTC_INTC_EXTENA1);
rtcss_write(davinci_rtc, 0, PRTCSS_RTC_CTRL);
rtcss_write(davinci_rtc, 0, PRTCSS_RTC_CCTRL);
ret = devm_request_irq(dev, davinci_rtc->irq, davinci_rtc_interrupt,
0, "davinci_rtc", davinci_rtc);
if (ret < 0) {
dev_err(dev, "unable to register davinci RTC interrupt\n");
return ret;
}
/* Enable interrupts */
rtcif_write(davinci_rtc, PRTCIF_INTEN_RTCSS, PRTCIF_INTEN);
rtcss_write(davinci_rtc, PRTCSS_RTC_INTC_EXTENA1_MASK,
PRTCSS_RTC_INTC_EXTENA1);
rtcss_write(davinci_rtc, PRTCSS_RTC_CCTRL_CAEN, PRTCSS_RTC_CCTRL);
device_init_wakeup(&pdev->dev, 0);
return devm_rtc_register_device(davinci_rtc->rtc);
}
static int __exit davinci_rtc_remove(struct platform_device *pdev)
{
struct davinci_rtc *davinci_rtc = platform_get_drvdata(pdev);
device_init_wakeup(&pdev->dev, 0);
rtcif_write(davinci_rtc, 0, PRTCIF_INTEN);
return 0;
}
static struct platform_driver davinci_rtc_driver = {
.remove = __exit_p(davinci_rtc_remove),
.driver = {
.name = "rtc_davinci",
},
};
module_platform_driver_probe(davinci_rtc_driver, davinci_rtc_probe);
MODULE_AUTHOR("Miguel Aguilar <miguel.aguilar@ridgerun.com>");
MODULE_DESCRIPTION("Texas Instruments DaVinci PRTC Driver");
MODULE_LICENSE("GPL");
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