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rtc: AB8500 RTC driver
Add a driver for the RTC on the AB8500 power management chip. This is a client of the AB8500 MFD driver. Signed-off-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com> Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Acked-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Samuel Ortiz <sameo@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Virupax Sadashivpetimath
Linus Torvalds
parent
7ca5ca60cb
commit
0af62f4d1e
@ -611,6 +611,13 @@ config RTC_DRV_AB3100
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Select this to enable the ST-Ericsson AB3100 Mixed Signal IC RTC
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support. This chip contains a battery- and capacitor-backed RTC.
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config RTC_DRV_AB8500
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tristate "ST-Ericsson AB8500 RTC"
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depends on AB8500_CORE
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help
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Select this to enable the ST-Ericsson AB8500 power management IC RTC
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support. This chip contains a battery- and capacitor-backed RTC.
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config RTC_DRV_NUC900
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tristate "NUC910/NUC920 RTC driver"
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depends on RTC_CLASS && ARCH_W90X900
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@ -18,6 +18,7 @@ rtc-core-$(CONFIG_RTC_INTF_SYSFS) += rtc-sysfs.o
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# Keep the list ordered.
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obj-$(CONFIG_RTC_DRV_AB3100) += rtc-ab3100.o
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obj-$(CONFIG_RTC_DRV_AB8500) += rtc-ab8500.o
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obj-$(CONFIG_RTC_DRV_AT32AP700X)+= rtc-at32ap700x.o
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obj-$(CONFIG_RTC_DRV_AT91RM9200)+= rtc-at91rm9200.o
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obj-$(CONFIG_RTC_DRV_AT91SAM9) += rtc-at91sam9.o
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363
drivers/rtc/rtc-ab8500.c
Normal file
363
drivers/rtc/rtc-ab8500.c
Normal file
@ -0,0 +1,363 @@
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/*
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* Copyright (C) ST-Ericsson SA 2010
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*
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* License terms: GNU General Public License (GPL) version 2
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* Author: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
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*
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* RTC clock driver for the RTC part of the AB8500 Power management chip.
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* Based on RTC clock driver for the AB3100 Analog Baseband Chip by
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* Linus Walleij <linus.walleij@stericsson.com>
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/rtc.h>
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#include <linux/mfd/ab8500.h>
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#include <linux/delay.h>
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#define AB8500_RTC_SOFF_STAT_REG 0x0F00
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#define AB8500_RTC_CC_CONF_REG 0x0F01
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#define AB8500_RTC_READ_REQ_REG 0x0F02
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#define AB8500_RTC_WATCH_TSECMID_REG 0x0F03
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#define AB8500_RTC_WATCH_TSECHI_REG 0x0F04
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#define AB8500_RTC_WATCH_TMIN_LOW_REG 0x0F05
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#define AB8500_RTC_WATCH_TMIN_MID_REG 0x0F06
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#define AB8500_RTC_WATCH_TMIN_HI_REG 0x0F07
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#define AB8500_RTC_ALRM_MIN_LOW_REG 0x0F08
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#define AB8500_RTC_ALRM_MIN_MID_REG 0x0F09
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#define AB8500_RTC_ALRM_MIN_HI_REG 0x0F0A
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#define AB8500_RTC_STAT_REG 0x0F0B
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#define AB8500_RTC_BKUP_CHG_REG 0x0F0C
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#define AB8500_RTC_FORCE_BKUP_REG 0x0F0D
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#define AB8500_RTC_CALIB_REG 0x0F0E
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#define AB8500_RTC_SWITCH_STAT_REG 0x0F0F
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#define AB8500_REV_REG 0x1080
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/* RtcReadRequest bits */
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#define RTC_READ_REQUEST 0x01
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#define RTC_WRITE_REQUEST 0x02
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/* RtcCtrl bits */
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#define RTC_ALARM_ENA 0x04
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#define RTC_STATUS_DATA 0x01
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#define COUNTS_PER_SEC (0xF000 / 60)
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#define AB8500_RTC_EPOCH 2000
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static const unsigned long ab8500_rtc_time_regs[] = {
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AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
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AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
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AB8500_RTC_WATCH_TSECMID_REG
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};
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static const unsigned long ab8500_rtc_alarm_regs[] = {
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AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
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AB8500_RTC_ALRM_MIN_LOW_REG
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};
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/* Calculate the seconds from 1970 to 01-01-2000 00:00:00 */
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static unsigned long get_elapsed_seconds(int year)
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{
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unsigned long secs;
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struct rtc_time tm = {
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.tm_year = year - 1900,
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.tm_mday = 1,
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};
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/*
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* This function calculates secs from 1970 and not from
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* 1900, even if we supply the offset from year 1900.
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*/
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rtc_tm_to_time(&tm, &secs);
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return secs;
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}
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static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
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{
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struct ab8500 *ab8500 = dev_get_drvdata(dev->parent);
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unsigned long timeout = jiffies + HZ;
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int retval, i;
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unsigned long mins, secs;
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unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
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/* Request a data read */
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retval = ab8500_write(ab8500, AB8500_RTC_READ_REQ_REG,
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RTC_READ_REQUEST);
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if (retval < 0)
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return retval;
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/* Early AB8500 chips will not clear the rtc read request bit */
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if (ab8500->revision == 0) {
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msleep(1);
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} else {
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/* Wait for some cycles after enabling the rtc read in ab8500 */
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while (time_before(jiffies, timeout)) {
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retval = ab8500_read(ab8500, AB8500_RTC_READ_REQ_REG);
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if (retval < 0)
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return retval;
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if (!(retval & RTC_READ_REQUEST))
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break;
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msleep(1);
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}
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}
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/* Read the Watchtime registers */
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for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
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retval = ab8500_read(ab8500, ab8500_rtc_time_regs[i]);
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if (retval < 0)
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return retval;
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buf[i] = retval;
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}
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mins = (buf[0] << 16) | (buf[1] << 8) | buf[2];
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secs = (buf[3] << 8) | buf[4];
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secs = secs / COUNTS_PER_SEC;
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secs = secs + (mins * 60);
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/* Add back the initially subtracted number of seconds */
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secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
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rtc_time_to_tm(secs, tm);
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return rtc_valid_tm(tm);
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}
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static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
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{
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struct ab8500 *ab8500 = dev_get_drvdata(dev->parent);
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int retval, i;
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unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
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unsigned long no_secs, no_mins, secs = 0;
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if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {
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dev_dbg(dev, "year should be equal to or greater than %d\n",
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AB8500_RTC_EPOCH);
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return -EINVAL;
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}
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/* Get the number of seconds since 1970 */
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rtc_tm_to_time(tm, &secs);
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/*
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* Convert it to the number of seconds since 01-01-2000 00:00:00, since
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* we only have a small counter in the RTC.
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*/
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secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
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no_mins = secs / 60;
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no_secs = secs % 60;
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/* Make the seconds count as per the RTC resolution */
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no_secs = no_secs * COUNTS_PER_SEC;
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buf[4] = no_secs & 0xFF;
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buf[3] = (no_secs >> 8) & 0xFF;
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buf[2] = no_mins & 0xFF;
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buf[1] = (no_mins >> 8) & 0xFF;
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buf[0] = (no_mins >> 16) & 0xFF;
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for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
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retval = ab8500_write(ab8500, ab8500_rtc_time_regs[i], buf[i]);
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if (retval < 0)
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return retval;
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}
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/* Request a data write */
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return ab8500_write(ab8500, AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
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}
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static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
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{
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struct ab8500 *ab8500 = dev_get_drvdata(dev->parent);
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int retval, i;
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int rtc_ctrl;
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unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
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unsigned long secs, mins;
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/* Check if the alarm is enabled or not */
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rtc_ctrl = ab8500_read(ab8500, AB8500_RTC_STAT_REG);
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if (rtc_ctrl < 0)
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return rtc_ctrl;
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if (rtc_ctrl & RTC_ALARM_ENA)
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alarm->enabled = 1;
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else
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alarm->enabled = 0;
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alarm->pending = 0;
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for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
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retval = ab8500_read(ab8500, ab8500_rtc_alarm_regs[i]);
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if (retval < 0)
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return retval;
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buf[i] = retval;
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}
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mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]);
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secs = mins * 60;
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/* Add back the initially subtracted number of seconds */
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secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
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rtc_time_to_tm(secs, &alarm->time);
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return rtc_valid_tm(&alarm->time);
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}
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static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
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{
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struct ab8500 *ab8500 = dev_get_drvdata(dev->parent);
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return ab8500_set_bits(ab8500, AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
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enabled ? RTC_ALARM_ENA : 0);
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}
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static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
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{
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struct ab8500 *ab8500 = dev_get_drvdata(dev->parent);
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int retval, i;
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unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
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unsigned long mins, secs = 0;
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if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
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dev_dbg(dev, "year should be equal to or greater than %d\n",
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AB8500_RTC_EPOCH);
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return -EINVAL;
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}
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/* Get the number of seconds since 1970 */
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rtc_tm_to_time(&alarm->time, &secs);
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/*
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* Convert it to the number of seconds since 01-01-2000 00:00:00, since
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* we only have a small counter in the RTC.
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*/
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secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
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mins = secs / 60;
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buf[2] = mins & 0xFF;
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buf[1] = (mins >> 8) & 0xFF;
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buf[0] = (mins >> 16) & 0xFF;
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/* Set the alarm time */
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for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
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retval = ab8500_write(ab8500, ab8500_rtc_alarm_regs[i], buf[i]);
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if (retval < 0)
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return retval;
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}
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return ab8500_rtc_irq_enable(dev, alarm->enabled);
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}
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static irqreturn_t rtc_alarm_handler(int irq, void *data)
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{
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struct rtc_device *rtc = data;
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unsigned long events = RTC_IRQF | RTC_AF;
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dev_dbg(&rtc->dev, "%s\n", __func__);
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rtc_update_irq(rtc, 1, events);
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return IRQ_HANDLED;
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}
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static const struct rtc_class_ops ab8500_rtc_ops = {
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.read_time = ab8500_rtc_read_time,
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.set_time = ab8500_rtc_set_time,
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.read_alarm = ab8500_rtc_read_alarm,
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.set_alarm = ab8500_rtc_set_alarm,
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.alarm_irq_enable = ab8500_rtc_irq_enable,
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};
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static int __devinit ab8500_rtc_probe(struct platform_device *pdev)
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{
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struct ab8500 *ab8500 = dev_get_drvdata(pdev->dev.parent);
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int err;
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struct rtc_device *rtc;
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int rtc_ctrl;
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int irq;
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irq = platform_get_irq_byname(pdev, "ALARM");
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if (irq < 0)
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return irq;
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/* For RTC supply test */
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err = ab8500_set_bits(ab8500, AB8500_RTC_STAT_REG, RTC_STATUS_DATA,
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RTC_STATUS_DATA);
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if (err < 0)
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return err;
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/* Wait for reset by the PorRtc */
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msleep(1);
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rtc_ctrl = ab8500_read(ab8500, AB8500_RTC_STAT_REG);
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if (rtc_ctrl < 0)
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return rtc_ctrl;
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/* Check if the RTC Supply fails */
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if (!(rtc_ctrl & RTC_STATUS_DATA)) {
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dev_err(&pdev->dev, "RTC supply failure\n");
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return -ENODEV;
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}
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rtc = rtc_device_register("ab8500-rtc", &pdev->dev, &ab8500_rtc_ops,
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THIS_MODULE);
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if (IS_ERR(rtc)) {
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dev_err(&pdev->dev, "Registration failed\n");
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err = PTR_ERR(rtc);
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return err;
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}
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err = request_threaded_irq(irq, NULL, rtc_alarm_handler, 0,
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"ab8500-rtc", rtc);
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if (err < 0) {
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rtc_device_unregister(rtc);
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return err;
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}
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platform_set_drvdata(pdev, rtc);
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return 0;
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}
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static int __devexit ab8500_rtc_remove(struct platform_device *pdev)
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{
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struct rtc_device *rtc = platform_get_drvdata(pdev);
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int irq = platform_get_irq_byname(pdev, "ALARM");
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free_irq(irq, rtc);
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rtc_device_unregister(rtc);
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platform_set_drvdata(pdev, NULL);
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return 0;
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}
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static struct platform_driver ab8500_rtc_driver = {
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.driver = {
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.name = "ab8500-rtc",
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.owner = THIS_MODULE,
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},
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.probe = ab8500_rtc_probe,
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.remove = __devexit_p(ab8500_rtc_remove),
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};
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static int __init ab8500_rtc_init(void)
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{
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return platform_driver_register(&ab8500_rtc_driver);
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}
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static void __exit ab8500_rtc_exit(void)
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{
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platform_driver_unregister(&ab8500_rtc_driver);
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}
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module_init(ab8500_rtc_init);
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module_exit(ab8500_rtc_exit);
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MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
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MODULE_DESCRIPTION("AB8500 RTC Driver");
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MODULE_LICENSE("GPL v2");
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