mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![Alexandre Belloni](/assets/img/avatar_default.png)
rtc_time64_to_tm never generates an invalid tm. It is not necessary to validate it. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
252 lines
6.4 KiB
C
252 lines
6.4 KiB
C
/*
|
|
* Copyright (C) 2007-2009 ST-Ericsson AB
|
|
* License terms: GNU General Public License (GPL) version 2
|
|
* RTC clock driver for the AB3100 Analog Baseband Chip
|
|
* Author: Linus Walleij <linus.walleij@stericsson.com>
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/mfd/abx500.h>
|
|
|
|
/* Clock rate in Hz */
|
|
#define AB3100_RTC_CLOCK_RATE 32768
|
|
|
|
/*
|
|
* The AB3100 RTC registers. These are the same for
|
|
* AB3000 and AB3100.
|
|
* Control register:
|
|
* Bit 0: RTC Monitor cleared=0, active=1, if you set it
|
|
* to 1 it remains active until RTC power is lost.
|
|
* Bit 1: 32 kHz Oscillator, 0 = on, 1 = bypass
|
|
* Bit 2: Alarm on, 0 = off, 1 = on
|
|
* Bit 3: 32 kHz buffer disabling, 0 = enabled, 1 = disabled
|
|
*/
|
|
#define AB3100_RTC 0x53
|
|
/* default setting, buffer disabled, alarm on */
|
|
#define RTC_SETTING 0x30
|
|
/* Alarm when AL0-AL3 == TI0-TI3 */
|
|
#define AB3100_AL0 0x56
|
|
#define AB3100_AL1 0x57
|
|
#define AB3100_AL2 0x58
|
|
#define AB3100_AL3 0x59
|
|
/* This 48-bit register that counts up at 32768 Hz */
|
|
#define AB3100_TI0 0x5a
|
|
#define AB3100_TI1 0x5b
|
|
#define AB3100_TI2 0x5c
|
|
#define AB3100_TI3 0x5d
|
|
#define AB3100_TI4 0x5e
|
|
#define AB3100_TI5 0x5f
|
|
|
|
/*
|
|
* RTC clock functions and device struct declaration
|
|
*/
|
|
static int ab3100_rtc_set_mmss(struct device *dev, time64_t secs)
|
|
{
|
|
u8 regs[] = {AB3100_TI0, AB3100_TI1, AB3100_TI2,
|
|
AB3100_TI3, AB3100_TI4, AB3100_TI5};
|
|
unsigned char buf[6];
|
|
u64 hw_counter = secs * AB3100_RTC_CLOCK_RATE * 2;
|
|
int err = 0;
|
|
int i;
|
|
|
|
buf[0] = (hw_counter) & 0xFF;
|
|
buf[1] = (hw_counter >> 8) & 0xFF;
|
|
buf[2] = (hw_counter >> 16) & 0xFF;
|
|
buf[3] = (hw_counter >> 24) & 0xFF;
|
|
buf[4] = (hw_counter >> 32) & 0xFF;
|
|
buf[5] = (hw_counter >> 40) & 0xFF;
|
|
|
|
for (i = 0; i < 6; i++) {
|
|
err = abx500_set_register_interruptible(dev, 0,
|
|
regs[i], buf[i]);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
/* Set the flag to mark that the clock is now set */
|
|
return abx500_mask_and_set_register_interruptible(dev, 0,
|
|
AB3100_RTC,
|
|
0x01, 0x01);
|
|
|
|
}
|
|
|
|
static int ab3100_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
time64_t time;
|
|
u8 rtcval;
|
|
int err;
|
|
|
|
err = abx500_get_register_interruptible(dev, 0,
|
|
AB3100_RTC, &rtcval);
|
|
if (err)
|
|
return err;
|
|
|
|
if (!(rtcval & 0x01)) {
|
|
dev_info(dev, "clock not set (lost power)");
|
|
return -EINVAL;
|
|
} else {
|
|
u64 hw_counter;
|
|
u8 buf[6];
|
|
|
|
/* Read out time registers */
|
|
err = abx500_get_register_page_interruptible(dev, 0,
|
|
AB3100_TI0,
|
|
buf, 6);
|
|
if (err != 0)
|
|
return err;
|
|
|
|
hw_counter = ((u64) buf[5] << 40) | ((u64) buf[4] << 32) |
|
|
((u64) buf[3] << 24) | ((u64) buf[2] << 16) |
|
|
((u64) buf[1] << 8) | (u64) buf[0];
|
|
time = hw_counter / (u64) (AB3100_RTC_CLOCK_RATE * 2);
|
|
}
|
|
|
|
rtc_time64_to_tm(time, tm);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ab3100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
|
|
{
|
|
time64_t time;
|
|
u64 hw_counter;
|
|
u8 buf[6];
|
|
u8 rtcval;
|
|
int err;
|
|
|
|
/* Figure out if alarm is enabled or not */
|
|
err = abx500_get_register_interruptible(dev, 0,
|
|
AB3100_RTC, &rtcval);
|
|
if (err)
|
|
return err;
|
|
if (rtcval & 0x04)
|
|
alarm->enabled = 1;
|
|
else
|
|
alarm->enabled = 0;
|
|
/* No idea how this could be represented */
|
|
alarm->pending = 0;
|
|
/* Read out alarm registers, only 4 bytes */
|
|
err = abx500_get_register_page_interruptible(dev, 0,
|
|
AB3100_AL0, buf, 4);
|
|
if (err)
|
|
return err;
|
|
hw_counter = ((u64) buf[3] << 40) | ((u64) buf[2] << 32) |
|
|
((u64) buf[1] << 24) | ((u64) buf[0] << 16);
|
|
time = hw_counter / (u64) (AB3100_RTC_CLOCK_RATE * 2);
|
|
|
|
rtc_time64_to_tm(time, &alarm->time);
|
|
|
|
return rtc_valid_tm(&alarm->time);
|
|
}
|
|
|
|
static int ab3100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
|
|
{
|
|
u8 regs[] = {AB3100_AL0, AB3100_AL1, AB3100_AL2, AB3100_AL3};
|
|
unsigned char buf[4];
|
|
time64_t secs;
|
|
u64 hw_counter;
|
|
int err;
|
|
int i;
|
|
|
|
secs = rtc_tm_to_time64(&alarm->time);
|
|
hw_counter = secs * AB3100_RTC_CLOCK_RATE * 2;
|
|
buf[0] = (hw_counter >> 16) & 0xFF;
|
|
buf[1] = (hw_counter >> 24) & 0xFF;
|
|
buf[2] = (hw_counter >> 32) & 0xFF;
|
|
buf[3] = (hw_counter >> 40) & 0xFF;
|
|
|
|
/* Set the alarm */
|
|
for (i = 0; i < 4; i++) {
|
|
err = abx500_set_register_interruptible(dev, 0,
|
|
regs[i], buf[i]);
|
|
if (err)
|
|
return err;
|
|
}
|
|
/* Then enable the alarm */
|
|
return abx500_mask_and_set_register_interruptible(dev, 0,
|
|
AB3100_RTC, (1 << 2),
|
|
alarm->enabled << 2);
|
|
}
|
|
|
|
static int ab3100_rtc_irq_enable(struct device *dev, unsigned int enabled)
|
|
{
|
|
/*
|
|
* It's not possible to enable/disable the alarm IRQ for this RTC.
|
|
* It does not actually trigger any IRQ: instead its only function is
|
|
* to power up the system, if it wasn't on. This will manifest as
|
|
* a "power up cause" in the AB3100 power driver (battery charging etc)
|
|
* and need to be handled there instead.
|
|
*/
|
|
if (enabled)
|
|
return abx500_mask_and_set_register_interruptible(dev, 0,
|
|
AB3100_RTC, (1 << 2),
|
|
1 << 2);
|
|
else
|
|
return abx500_mask_and_set_register_interruptible(dev, 0,
|
|
AB3100_RTC, (1 << 2),
|
|
0);
|
|
}
|
|
|
|
static const struct rtc_class_ops ab3100_rtc_ops = {
|
|
.read_time = ab3100_rtc_read_time,
|
|
.set_mmss64 = ab3100_rtc_set_mmss,
|
|
.read_alarm = ab3100_rtc_read_alarm,
|
|
.set_alarm = ab3100_rtc_set_alarm,
|
|
.alarm_irq_enable = ab3100_rtc_irq_enable,
|
|
};
|
|
|
|
static int __init ab3100_rtc_probe(struct platform_device *pdev)
|
|
{
|
|
int err;
|
|
u8 regval;
|
|
struct rtc_device *rtc;
|
|
|
|
/* The first RTC register needs special treatment */
|
|
err = abx500_get_register_interruptible(&pdev->dev, 0,
|
|
AB3100_RTC, ®val);
|
|
if (err) {
|
|
dev_err(&pdev->dev, "unable to read RTC register\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
if ((regval & 0xFE) != RTC_SETTING) {
|
|
dev_warn(&pdev->dev, "not default value in RTC reg 0x%x\n",
|
|
regval);
|
|
}
|
|
|
|
if ((regval & 1) == 0) {
|
|
/*
|
|
* Set bit to detect power loss.
|
|
* This bit remains until RTC power is lost.
|
|
*/
|
|
regval = 1 | RTC_SETTING;
|
|
err = abx500_set_register_interruptible(&pdev->dev, 0,
|
|
AB3100_RTC, regval);
|
|
/* Ignore any error on this write */
|
|
}
|
|
|
|
rtc = devm_rtc_device_register(&pdev->dev, "ab3100-rtc",
|
|
&ab3100_rtc_ops, THIS_MODULE);
|
|
if (IS_ERR(rtc)) {
|
|
err = PTR_ERR(rtc);
|
|
return err;
|
|
}
|
|
platform_set_drvdata(pdev, rtc);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver ab3100_rtc_driver = {
|
|
.driver = {
|
|
.name = "ab3100-rtc",
|
|
},
|
|
};
|
|
|
|
module_platform_driver_probe(ab3100_rtc_driver, ab3100_rtc_probe);
|
|
|
|
MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
|
|
MODULE_DESCRIPTION("AB3100 RTC Driver");
|
|
MODULE_LICENSE("GPL");
|