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linux/drivers/rtc/rtc-ab8500.c
Linus Torvalds e6b5be2be4 Driver core patches for 3.19-rc1 
Here's the set of driver core patches for 3.19-rc1.
 
 They are dominated by the removal of the .owner field in platform
 drivers.  They touch a lot of files, but they are "simple" changes, just
 removing a line in a structure.
 
 Other than that, a few minor driver core and debugfs changes.  There are
 some ath9k patches coming in through this tree that have been acked by
 the wireless maintainers as they relied on the debugfs changes.
 
 Everything has been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_<level>_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
2014-12-14 16:10:09 -08:00

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/*
* Copyright (C) ST-Ericsson SA 2010
*
* License terms: GNU General Public License (GPL) version 2
* Author: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
*
* RTC clock driver for the RTC part of the AB8500 Power management chip.
* Based on RTC clock driver for the AB3100 Analog Baseband Chip by
* 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>
#include <linux/mfd/abx500/ab8500.h>
#include <linux/delay.h>
#include <linux/of.h>
#define AB8500_RTC_SOFF_STAT_REG 0x00
#define AB8500_RTC_CC_CONF_REG 0x01
#define AB8500_RTC_READ_REQ_REG 0x02
#define AB8500_RTC_WATCH_TSECMID_REG 0x03
#define AB8500_RTC_WATCH_TSECHI_REG 0x04
#define AB8500_RTC_WATCH_TMIN_LOW_REG 0x05
#define AB8500_RTC_WATCH_TMIN_MID_REG 0x06
#define AB8500_RTC_WATCH_TMIN_HI_REG 0x07
#define AB8500_RTC_ALRM_MIN_LOW_REG 0x08
#define AB8500_RTC_ALRM_MIN_MID_REG 0x09
#define AB8500_RTC_ALRM_MIN_HI_REG 0x0A
#define AB8500_RTC_STAT_REG 0x0B
#define AB8500_RTC_BKUP_CHG_REG 0x0C
#define AB8500_RTC_FORCE_BKUP_REG 0x0D
#define AB8500_RTC_CALIB_REG 0x0E
#define AB8500_RTC_SWITCH_STAT_REG 0x0F
#define AB8540_RTC_ALRM_SEC 0x22
#define AB8540_RTC_ALRM_MIN_LOW_REG 0x23
#define AB8540_RTC_ALRM_MIN_MID_REG 0x24
#define AB8540_RTC_ALRM_MIN_HI_REG 0x25
/* RtcReadRequest bits */
#define RTC_READ_REQUEST 0x01
#define RTC_WRITE_REQUEST 0x02
/* RtcCtrl bits */
#define RTC_ALARM_ENA 0x04
#define RTC_STATUS_DATA 0x01
#define COUNTS_PER_SEC (0xF000 / 60)
#define AB8500_RTC_EPOCH 2000
static const u8 ab8500_rtc_time_regs[] = {
AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,
AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,
AB8500_RTC_WATCH_TSECMID_REG
};
static const u8 ab8500_rtc_alarm_regs[] = {
AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,
AB8500_RTC_ALRM_MIN_LOW_REG
};
static const u8 ab8540_rtc_alarm_regs[] = {
AB8540_RTC_ALRM_MIN_HI_REG, AB8540_RTC_ALRM_MIN_MID_REG,
AB8540_RTC_ALRM_MIN_LOW_REG, AB8540_RTC_ALRM_SEC
};
/* Calculate the seconds from 1970 to 01-01-2000 00:00:00 */
static unsigned long get_elapsed_seconds(int year)
{
unsigned long secs;
struct rtc_time tm = {
.tm_year = year - 1900,
.tm_mday = 1,
};
/*
* This function calculates secs from 1970 and not from
* 1900, even if we supply the offset from year 1900.
*/
rtc_tm_to_time(&tm, &secs);
return secs;
}
static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
unsigned long timeout = jiffies + HZ;
int retval, i;
unsigned long mins, secs;
unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
u8 value;
/* Request a data read */
retval = abx500_set_register_interruptible(dev,
AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);
if (retval < 0)
return retval;
/* Wait for some cycles after enabling the rtc read in ab8500 */
while (time_before(jiffies, timeout)) {
retval = abx500_get_register_interruptible(dev,
AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);
if (retval < 0)
return retval;
if (!(value & RTC_READ_REQUEST))
break;
usleep_range(1000, 5000);
}
/* Read the Watchtime registers */
for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
retval = abx500_get_register_interruptible(dev,
AB8500_RTC, ab8500_rtc_time_regs[i], &value);
if (retval < 0)
return retval;
buf[i] = value;
}
mins = (buf[0] << 16) | (buf[1] << 8) | buf[2];
secs = (buf[3] << 8) | buf[4];
secs = secs / COUNTS_PER_SEC;
secs = secs + (mins * 60);
/* Add back the initially subtracted number of seconds */
secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
rtc_time_to_tm(secs, tm);
return rtc_valid_tm(tm);
}
static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
int retval, i;
unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];
unsigned long no_secs, no_mins, secs = 0;
if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) {
dev_dbg(dev, "year should be equal to or greater than %d\n",
AB8500_RTC_EPOCH);
return -EINVAL;
}
/* Get the number of seconds since 1970 */
rtc_tm_to_time(tm, &secs);
/*
* Convert it to the number of seconds since 01-01-2000 00:00:00, since
* we only have a small counter in the RTC.
*/
secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
no_mins = secs / 60;
no_secs = secs % 60;
/* Make the seconds count as per the RTC resolution */
no_secs = no_secs * COUNTS_PER_SEC;
buf[4] = no_secs & 0xFF;
buf[3] = (no_secs >> 8) & 0xFF;
buf[2] = no_mins & 0xFF;
buf[1] = (no_mins >> 8) & 0xFF;
buf[0] = (no_mins >> 16) & 0xFF;
for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {
retval = abx500_set_register_interruptible(dev, AB8500_RTC,
ab8500_rtc_time_regs[i], buf[i]);
if (retval < 0)
return retval;
}
/* Request a data write */
return abx500_set_register_interruptible(dev, AB8500_RTC,
AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);
}
static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
int retval, i;
u8 rtc_ctrl, value;
unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
unsigned long secs, mins;
/* Check if the alarm is enabled or not */
retval = abx500_get_register_interruptible(dev, AB8500_RTC,
AB8500_RTC_STAT_REG, &rtc_ctrl);
if (retval < 0)
return retval;
if (rtc_ctrl & RTC_ALARM_ENA)
alarm->enabled = 1;
else
alarm->enabled = 0;
alarm->pending = 0;
for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
retval = abx500_get_register_interruptible(dev, AB8500_RTC,
ab8500_rtc_alarm_regs[i], &value);
if (retval < 0)
return retval;
buf[i] = value;
}
mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]);
secs = mins * 60;
/* Add back the initially subtracted number of seconds */
secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
rtc_time_to_tm(secs, &alarm->time);
return rtc_valid_tm(&alarm->time);
}
static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled)
{
return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,
AB8500_RTC_STAT_REG, RTC_ALARM_ENA,
enabled ? RTC_ALARM_ENA : 0);
}
static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
int retval, i;
unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];
unsigned long mins, secs = 0, cursec = 0;
struct rtc_time curtm;
if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
dev_dbg(dev, "year should be equal to or greater than %d\n",
AB8500_RTC_EPOCH);
return -EINVAL;
}
/* Get the number of seconds since 1970 */
rtc_tm_to_time(&alarm->time, &secs);
/*
* Check whether alarm is set less than 1min.
* Since our RTC doesn't support alarm resolution less than 1min,
* return -EINVAL, so UIE EMUL can take it up, incase of UIE_ON
*/
ab8500_rtc_read_time(dev, &curtm); /* Read current time */
rtc_tm_to_time(&curtm, &cursec);
if ((secs - cursec) < 59) {
dev_dbg(dev, "Alarm less than 1 minute not supported\r\n");
return -EINVAL;
}
/*
* Convert it to the number of seconds since 01-01-2000 00:00:00, since
* we only have a small counter in the RTC.
*/
secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
mins = secs / 60;
buf[2] = mins & 0xFF;
buf[1] = (mins >> 8) & 0xFF;
buf[0] = (mins >> 16) & 0xFF;
/* Set the alarm time */
for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {
retval = abx500_set_register_interruptible(dev, AB8500_RTC,
ab8500_rtc_alarm_regs[i], buf[i]);
if (retval < 0)
return retval;
}
return ab8500_rtc_irq_enable(dev, alarm->enabled);
}
static int ab8540_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
int retval, i;
unsigned char buf[ARRAY_SIZE(ab8540_rtc_alarm_regs)];
unsigned long mins, secs = 0;
if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) {
dev_dbg(dev, "year should be equal to or greater than %d\n",
AB8500_RTC_EPOCH);
return -EINVAL;
}
/* Get the number of seconds since 1970 */
rtc_tm_to_time(&alarm->time, &secs);
/*
* Convert it to the number of seconds since 01-01-2000 00:00:00
*/
secs -= get_elapsed_seconds(AB8500_RTC_EPOCH);
mins = secs / 60;
buf[3] = secs % 60;
buf[2] = mins & 0xFF;
buf[1] = (mins >> 8) & 0xFF;
buf[0] = (mins >> 16) & 0xFF;
/* Set the alarm time */
for (i = 0; i < ARRAY_SIZE(ab8540_rtc_alarm_regs); i++) {
retval = abx500_set_register_interruptible(dev, AB8500_RTC,
ab8540_rtc_alarm_regs[i], buf[i]);
if (retval < 0)
return retval;
}
return ab8500_rtc_irq_enable(dev, alarm->enabled);
}
static int ab8500_rtc_set_calibration(struct device *dev, int calibration)
{
int retval;
u8 rtccal = 0;
/*
* Check that the calibration value (which is in units of 0.5
* parts-per-million) is in the AB8500's range for RtcCalibration
* register. -128 (0x80) is not permitted because the AB8500 uses
* a sign-bit rather than two's complement, so 0x80 is just another
* representation of zero.
*/
if ((calibration < -127) || (calibration > 127)) {
dev_err(dev, "RtcCalibration value outside permitted range\n");
return -EINVAL;
}
/*
* The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
* so need to convert to this sort of representation before writing
* into RtcCalibration register...
*/
if (calibration >= 0)
rtccal = 0x7F & calibration;
else
rtccal = ~(calibration - 1) | 0x80;
retval = abx500_set_register_interruptible(dev, AB8500_RTC,
AB8500_RTC_CALIB_REG, rtccal);
return retval;
}
static int ab8500_rtc_get_calibration(struct device *dev, int *calibration)
{
int retval;
u8 rtccal = 0;
retval = abx500_get_register_interruptible(dev, AB8500_RTC,
AB8500_RTC_CALIB_REG, &rtccal);
if (retval >= 0) {
/*
* The AB8500 uses sign (in bit7) and magnitude (in bits0-7)
* so need to convert value from RtcCalibration register into
* a two's complement signed value...
*/
if (rtccal & 0x80)
*calibration = 0 - (rtccal & 0x7F);
else
*calibration = 0x7F & rtccal;
}
return retval;
}
static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int retval;
int calibration = 0;
if (sscanf(buf, " %i ", &calibration) != 1) {
dev_err(dev, "Failed to store RTC calibration attribute\n");
return -EINVAL;
}
retval = ab8500_rtc_set_calibration(dev, calibration);
return retval ? retval : count;
}
static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,
struct device_attribute *attr, char *buf)
{
int retval = 0;
int calibration = 0;
retval = ab8500_rtc_get_calibration(dev, &calibration);
if (retval < 0) {
dev_err(dev, "Failed to read RTC calibration attribute\n");
sprintf(buf, "0\n");
return retval;
}
return sprintf(buf, "%d\n", calibration);
}
static DEVICE_ATTR(rtc_calibration, S_IRUGO | S_IWUSR,
ab8500_sysfs_show_rtc_calibration,
ab8500_sysfs_store_rtc_calibration);
static int ab8500_sysfs_rtc_register(struct device *dev)
{
return device_create_file(dev, &dev_attr_rtc_calibration);
}
static void ab8500_sysfs_rtc_unregister(struct device *dev)
{
device_remove_file(dev, &dev_attr_rtc_calibration);
}
static irqreturn_t rtc_alarm_handler(int irq, void *data)
{
struct rtc_device *rtc = data;
unsigned long events = RTC_IRQF | RTC_AF;
dev_dbg(&rtc->dev, "%s\n", __func__);
rtc_update_irq(rtc, 1, events);
return IRQ_HANDLED;
}
static const struct rtc_class_ops ab8500_rtc_ops = {
.read_time = ab8500_rtc_read_time,
.set_time = ab8500_rtc_set_time,
.read_alarm = ab8500_rtc_read_alarm,
.set_alarm = ab8500_rtc_set_alarm,
.alarm_irq_enable = ab8500_rtc_irq_enable,
};
static const struct rtc_class_ops ab8540_rtc_ops = {
.read_time = ab8500_rtc_read_time,
.set_time = ab8500_rtc_set_time,
.read_alarm = ab8500_rtc_read_alarm,
.set_alarm = ab8540_rtc_set_alarm,
.alarm_irq_enable = ab8500_rtc_irq_enable,
};
static struct platform_device_id ab85xx_rtc_ids[] = {
{ "ab8500-rtc", (kernel_ulong_t)&ab8500_rtc_ops, },
{ "ab8540-rtc", (kernel_ulong_t)&ab8540_rtc_ops, },
};
static int ab8500_rtc_probe(struct platform_device *pdev)
{
const struct platform_device_id *platid = platform_get_device_id(pdev);
int err;
struct rtc_device *rtc;
u8 rtc_ctrl;
int irq;
irq = platform_get_irq_byname(pdev, "ALARM");
if (irq < 0)
return irq;
/* For RTC supply test */
err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,
AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);
if (err < 0)
return err;
/* Wait for reset by the PorRtc */
usleep_range(1000, 5000);
err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
AB8500_RTC_STAT_REG, &rtc_ctrl);
if (err < 0)
return err;
/* Check if the RTC Supply fails */
if (!(rtc_ctrl & RTC_STATUS_DATA)) {
dev_err(&pdev->dev, "RTC supply failure\n");
return -ENODEV;
}
device_init_wakeup(&pdev->dev, true);
rtc = devm_rtc_device_register(&pdev->dev, "ab8500-rtc",
(struct rtc_class_ops *)platid->driver_data,
THIS_MODULE);
if (IS_ERR(rtc)) {
dev_err(&pdev->dev, "Registration failed\n");
err = PTR_ERR(rtc);
return err;
}
err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
rtc_alarm_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
"ab8500-rtc", rtc);
if (err < 0)
return err;
platform_set_drvdata(pdev, rtc);
err = ab8500_sysfs_rtc_register(&pdev->dev);
if (err) {
dev_err(&pdev->dev, "sysfs RTC failed to register\n");
return err;
}
rtc->uie_unsupported = 1;
return 0;
}
static int ab8500_rtc_remove(struct platform_device *pdev)
{
ab8500_sysfs_rtc_unregister(&pdev->dev);
return 0;
}
static struct platform_driver ab8500_rtc_driver = {
.driver = {
.name = "ab8500-rtc",
},
.probe = ab8500_rtc_probe,
.remove = ab8500_rtc_remove,
.id_table = ab85xx_rtc_ids,
};
module_platform_driver(ab8500_rtc_driver);
MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");
MODULE_DESCRIPTION("AB8500 RTC Driver");
MODULE_LICENSE("GPL v2");
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