linux/drivers/rtc/rtc-ab3100.c
Mattias Wallin fa661258a2 mfd: AB3100 register access change to abx500 API
The interface for the AB3100 is changed to make way for the
ABX500 family of chips: AB3550, AB5500 and future ST-Ericsson
Analog Baseband chips. The register access functions are moved
out to a separate struct abx500_ops. In this way the interface
is moved from the implementation and the sub functionality drivers
can keep their interface intact when chip infrastructure and
communication mechanisms changes. We also define the AB3550
device IDs and the AB3550 platform data struct and convert
the catenated 32bit event to an array of 3 x 8bits.

Signed-off-by: Mattias Wallin <mattias.wallin@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2010-05-28 01:37:45 +02:00

274 lines
6.8 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, unsigned long secs)
{
u8 regs[] = {AB3100_TI0, AB3100_TI1, AB3100_TI2,
AB3100_TI3, AB3100_TI4, AB3100_TI5};
unsigned char buf[6];
u64 fat_time = (u64) secs * AB3100_RTC_CLOCK_RATE * 2;
int err = 0;
int i;
buf[0] = (fat_time) & 0xFF;
buf[1] = (fat_time >> 8) & 0xFF;
buf[2] = (fat_time >> 16) & 0xFF;
buf[3] = (fat_time >> 24) & 0xFF;
buf[4] = (fat_time >> 32) & 0xFF;
buf[5] = (fat_time >> 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)
{
unsigned long 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 fat_time;
u8 buf[6];
/* Read out time registers */
err = abx500_get_register_page_interruptible(dev, 0,
AB3100_TI0,
buf, 6);
if (err != 0)
return err;
fat_time = ((u64) buf[5] << 40) | ((u64) buf[4] << 32) |
((u64) buf[3] << 24) | ((u64) buf[2] << 16) |
((u64) buf[1] << 8) | (u64) buf[0];
time = (unsigned long) (fat_time /
(u64) (AB3100_RTC_CLOCK_RATE * 2));
}
rtc_time_to_tm(time, tm);
return rtc_valid_tm(tm);
}
static int ab3100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
unsigned long time;
u64 fat_time;
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;
fat_time = ((u64) buf[3] << 40) | ((u64) buf[2] << 32) |
((u64) buf[1] << 24) | ((u64) buf[0] << 16);
time = (unsigned long) (fat_time / (u64) (AB3100_RTC_CLOCK_RATE * 2));
rtc_time_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];
unsigned long secs;
u64 fat_time;
int err;
int i;
rtc_tm_to_time(&alarm->time, &secs);
fat_time = (u64) secs * AB3100_RTC_CLOCK_RATE * 2;
buf[0] = (fat_time >> 16) & 0xFF;
buf[1] = (fat_time >> 24) & 0xFF;
buf[2] = (fat_time >> 32) & 0xFF;
buf[3] = (fat_time >> 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_mmss = 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, &regval);
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 = rtc_device_register("ab3100-rtc", &pdev->dev, &ab3100_rtc_ops,
THIS_MODULE);
if (IS_ERR(rtc)) {
err = PTR_ERR(rtc);
return err;
}
return 0;
}
static int __exit ab3100_rtc_remove(struct platform_device *pdev)
{
struct rtc_device *rtc = platform_get_drvdata(pdev);
rtc_device_unregister(rtc);
return 0;
}
static struct platform_driver ab3100_rtc_driver = {
.driver = {
.name = "ab3100-rtc",
.owner = THIS_MODULE,
},
.remove = __exit_p(ab3100_rtc_remove),
};
static int __init ab3100_rtc_init(void)
{
return platform_driver_probe(&ab3100_rtc_driver,
ab3100_rtc_probe);
}
static void __exit ab3100_rtc_exit(void)
{
platform_driver_unregister(&ab3100_rtc_driver);
}
module_init(ab3100_rtc_init);
module_exit(ab3100_rtc_exit);
MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
MODULE_DESCRIPTION("AB3100 RTC Driver");
MODULE_LICENSE("GPL");