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alistair23-linux/drivers/rtc/rtc-wm8350.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Real Time Clock driver for Wolfson Microelectronics WM8350
*
* Copyright (C) 2007, 2008 Wolfson Microelectronics PLC.
*
* Author: Liam Girdwood
* linux@wolfsonmicro.com
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/interrupt.h>
#include <linux/ioctl.h>
#include <linux/completion.h>
#include <linux/mfd/wm8350/rtc.h>
#include <linux/mfd/wm8350/core.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#define WM8350_SET_ALM_RETRIES 5
#define WM8350_SET_TIME_RETRIES 5
#define WM8350_GET_TIME_RETRIES 5
/*
* Read current time and date in RTC
*/
static int wm8350_rtc_readtime(struct device *dev, struct rtc_time *tm)
{
struct wm8350 *wm8350 = dev_get_drvdata(dev);
u16 time1[4], time2[4];
int retries = WM8350_GET_TIME_RETRIES, ret;
/*
* Read the time twice and compare.
* If time1 == time2, then time is valid else retry.
*/
do {
ret = wm8350_block_read(wm8350, WM8350_RTC_SECONDS_MINUTES,
4, time1);
if (ret < 0)
return ret;
ret = wm8350_block_read(wm8350, WM8350_RTC_SECONDS_MINUTES,
4, time2);
if (ret < 0)
return ret;
if (memcmp(time1, time2, sizeof(time1)) == 0) {
tm->tm_sec = time1[0] & WM8350_RTC_SECS_MASK;
tm->tm_min = (time1[0] & WM8350_RTC_MINS_MASK)
>> WM8350_RTC_MINS_SHIFT;
tm->tm_hour = time1[1] & WM8350_RTC_HRS_MASK;
tm->tm_wday = ((time1[1] >> WM8350_RTC_DAY_SHIFT)
& 0x7) - 1;
tm->tm_mon = ((time1[2] & WM8350_RTC_MTH_MASK)
>> WM8350_RTC_MTH_SHIFT) - 1;
tm->tm_mday = (time1[2] & WM8350_RTC_DATE_MASK);
tm->tm_year = ((time1[3] & WM8350_RTC_YHUNDREDS_MASK)
>> WM8350_RTC_YHUNDREDS_SHIFT) * 100;
tm->tm_year += time1[3] & WM8350_RTC_YUNITS_MASK;
tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon,
tm->tm_year);
tm->tm_year -= 1900;
dev_dbg(dev, "Read (%d left): %04x %04x %04x %04x\n",
retries,
time1[0], time1[1], time1[2], time1[3]);
return 0;
}
} while (retries--);
dev_err(dev, "timed out reading RTC time\n");
return -EIO;
}
/*
* Set current time and date in RTC
*/
static int wm8350_rtc_settime(struct device *dev, struct rtc_time *tm)
{
struct wm8350 *wm8350 = dev_get_drvdata(dev);
u16 time[4];
u16 rtc_ctrl;
int ret, retries = WM8350_SET_TIME_RETRIES;
time[0] = tm->tm_sec;
time[0] |= tm->tm_min << WM8350_RTC_MINS_SHIFT;
time[1] = tm->tm_hour;
time[1] |= (tm->tm_wday + 1) << WM8350_RTC_DAY_SHIFT;
time[2] = tm->tm_mday;
time[2] |= (tm->tm_mon + 1) << WM8350_RTC_MTH_SHIFT;
time[3] = ((tm->tm_year + 1900) / 100) << WM8350_RTC_YHUNDREDS_SHIFT;
time[3] |= (tm->tm_year + 1900) % 100;
dev_dbg(dev, "Setting: %04x %04x %04x %04x\n",
time[0], time[1], time[2], time[3]);
/* Set RTC_SET to stop the clock */
ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL, WM8350_RTC_SET);
if (ret < 0)
return ret;
/* Wait until confirmation of stopping */
do {
rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
schedule_timeout_uninterruptible(msecs_to_jiffies(1));
} while (--retries && !(rtc_ctrl & WM8350_RTC_STS));
if (!retries) {
dev_err(dev, "timed out on set confirmation\n");
return -EIO;
}
/* Write time to RTC */
ret = wm8350_block_write(wm8350, WM8350_RTC_SECONDS_MINUTES, 4, time);
if (ret < 0)
return ret;
/* Clear RTC_SET to start the clock */
ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,
WM8350_RTC_SET);
return ret;
}
/*
* Read alarm time and date in RTC
*/
static int wm8350_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct wm8350 *wm8350 = dev_get_drvdata(dev);
struct rtc_time *tm = &alrm->time;
u16 time[4];
int ret;
ret = wm8350_block_read(wm8350, WM8350_ALARM_SECONDS_MINUTES, 4, time);
if (ret < 0)
return ret;
tm->tm_sec = time[0] & WM8350_RTC_ALMSECS_MASK;
if (tm->tm_sec == WM8350_RTC_ALMSECS_MASK)
tm->tm_sec = -1;
tm->tm_min = time[0] & WM8350_RTC_ALMMINS_MASK;
if (tm->tm_min == WM8350_RTC_ALMMINS_MASK)
tm->tm_min = -1;
else
tm->tm_min >>= WM8350_RTC_ALMMINS_SHIFT;
tm->tm_hour = time[1] & WM8350_RTC_ALMHRS_MASK;
if (tm->tm_hour == WM8350_RTC_ALMHRS_MASK)
tm->tm_hour = -1;
tm->tm_wday = ((time[1] >> WM8350_RTC_ALMDAY_SHIFT) & 0x7) - 1;
if (tm->tm_wday > 7)
tm->tm_wday = -1;
tm->tm_mon = time[2] & WM8350_RTC_ALMMTH_MASK;
if (tm->tm_mon == WM8350_RTC_ALMMTH_MASK)
tm->tm_mon = -1;
else
tm->tm_mon = (tm->tm_mon >> WM8350_RTC_ALMMTH_SHIFT) - 1;
tm->tm_mday = (time[2] & WM8350_RTC_ALMDATE_MASK);
if (tm->tm_mday == WM8350_RTC_ALMDATE_MASK)
tm->tm_mday = -1;
tm->tm_year = -1;
alrm->enabled = !(time[3] & WM8350_RTC_ALMSTS);
return 0;
}
static int wm8350_rtc_stop_alarm(struct wm8350 *wm8350)
{
int retries = WM8350_SET_ALM_RETRIES;
u16 rtc_ctrl;
int ret;
/* Set RTC_SET to stop the clock */
ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL,
WM8350_RTC_ALMSET);
if (ret < 0)
return ret;
/* Wait until confirmation of stopping */
do {
rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
schedule_timeout_uninterruptible(msecs_to_jiffies(1));
} while (retries-- && !(rtc_ctrl & WM8350_RTC_ALMSTS));
if (!(rtc_ctrl & WM8350_RTC_ALMSTS))
return -ETIMEDOUT;
return 0;
}
static int wm8350_rtc_start_alarm(struct wm8350 *wm8350)
{
int ret;
int retries = WM8350_SET_ALM_RETRIES;
u16 rtc_ctrl;
ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,
WM8350_RTC_ALMSET);
if (ret < 0)
return ret;
/* Wait until confirmation */
do {
rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
schedule_timeout_uninterruptible(msecs_to_jiffies(1));
} while (retries-- && rtc_ctrl & WM8350_RTC_ALMSTS);
if (rtc_ctrl & WM8350_RTC_ALMSTS)
return -ETIMEDOUT;
return 0;
}
static int wm8350_rtc_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct wm8350 *wm8350 = dev_get_drvdata(dev);
if (enabled)
return wm8350_rtc_start_alarm(wm8350);
else
return wm8350_rtc_stop_alarm(wm8350);
}
static int wm8350_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct wm8350 *wm8350 = dev_get_drvdata(dev);
struct rtc_time *tm = &alrm->time;
u16 time[3];
int ret;
memset(time, 0, sizeof(time));
if (tm->tm_sec != -1)
time[0] |= tm->tm_sec;
else
time[0] |= WM8350_RTC_ALMSECS_MASK;
if (tm->tm_min != -1)
time[0] |= tm->tm_min << WM8350_RTC_ALMMINS_SHIFT;
else
time[0] |= WM8350_RTC_ALMMINS_MASK;
if (tm->tm_hour != -1)
time[1] |= tm->tm_hour;
else
time[1] |= WM8350_RTC_ALMHRS_MASK;
if (tm->tm_wday != -1)
time[1] |= (tm->tm_wday + 1) << WM8350_RTC_ALMDAY_SHIFT;
else
time[1] |= WM8350_RTC_ALMDAY_MASK;
if (tm->tm_mday != -1)
time[2] |= tm->tm_mday;
else
time[2] |= WM8350_RTC_ALMDATE_MASK;
if (tm->tm_mon != -1)
time[2] |= (tm->tm_mon + 1) << WM8350_RTC_ALMMTH_SHIFT;
else
time[2] |= WM8350_RTC_ALMMTH_MASK;
ret = wm8350_rtc_stop_alarm(wm8350);
if (ret < 0)
return ret;
/* Write time to RTC */
ret = wm8350_block_write(wm8350, WM8350_ALARM_SECONDS_MINUTES,
3, time);
if (ret < 0)
return ret;
if (alrm->enabled)
ret = wm8350_rtc_start_alarm(wm8350);
return ret;
}
static irqreturn_t wm8350_rtc_alarm_handler(int irq, void *data)
{
struct wm8350 *wm8350 = data;
struct rtc_device *rtc = wm8350->rtc.rtc;
int ret;
rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
/* Make it one shot */
ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL,
WM8350_RTC_ALMSET);
if (ret != 0) {
dev_err(&(wm8350->rtc.pdev->dev),
"Failed to disable alarm: %d\n", ret);
}
return IRQ_HANDLED;
}
static irqreturn_t wm8350_rtc_update_handler(int irq, void *data)
{
struct wm8350 *wm8350 = data;
struct rtc_device *rtc = wm8350->rtc.rtc;
rtc_update_irq(rtc, 1, RTC_IRQF | RTC_UF);
return IRQ_HANDLED;
}
static const struct rtc_class_ops wm8350_rtc_ops = {
.read_time = wm8350_rtc_readtime,
.set_time = wm8350_rtc_settime,
.read_alarm = wm8350_rtc_readalarm,
.set_alarm = wm8350_rtc_setalarm,
.alarm_irq_enable = wm8350_rtc_alarm_irq_enable,
};
#ifdef CONFIG_PM_SLEEP
static int wm8350_rtc_suspend(struct device *dev)
{
struct wm8350 *wm8350 = dev_get_drvdata(dev);
int ret = 0;
u16 reg;
reg = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
if (device_may_wakeup(&wm8350->rtc.pdev->dev) &&
reg & WM8350_RTC_ALMSTS) {
ret = wm8350_rtc_stop_alarm(wm8350);
if (ret != 0)
dev_err(dev, "Failed to stop RTC alarm: %d\n", ret);
}
return ret;
}
static int wm8350_rtc_resume(struct device *dev)
{
struct wm8350 *wm8350 = dev_get_drvdata(dev);
int ret;
if (wm8350->rtc.alarm_enabled) {
ret = wm8350_rtc_start_alarm(wm8350);
if (ret != 0)
dev_err(dev, "Failed to restart RTC alarm: %d\n", ret);
}
return 0;
}
#endif
static int wm8350_rtc_probe(struct platform_device *pdev)
{
struct wm8350 *wm8350 = platform_get_drvdata(pdev);
struct wm8350_rtc *wm_rtc = &wm8350->rtc;
int ret = 0;
u16 timectl, power5;
timectl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
if (timectl & WM8350_RTC_BCD) {
dev_err(&pdev->dev, "RTC BCD mode not supported\n");
return -EINVAL;
}
if (timectl & WM8350_RTC_12HR) {
dev_err(&pdev->dev, "RTC 12 hour mode not supported\n");
return -EINVAL;
}
/* enable the RTC if it's not already enabled */
power5 = wm8350_reg_read(wm8350, WM8350_POWER_MGMT_5);
if (!(power5 & WM8350_RTC_TICK_ENA)) {
dev_info(wm8350->dev, "Starting RTC\n");
wm8350_reg_unlock(wm8350);
ret = wm8350_set_bits(wm8350, WM8350_POWER_MGMT_5,
WM8350_RTC_TICK_ENA);
if (ret < 0) {
dev_err(&pdev->dev, "failed to enable RTC: %d\n", ret);
return ret;
}
wm8350_reg_lock(wm8350);
}
if (timectl & WM8350_RTC_STS) {
int retries;
ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,
WM8350_RTC_SET);
if (ret < 0) {
dev_err(&pdev->dev, "failed to start: %d\n", ret);
return ret;
}
retries = WM8350_SET_TIME_RETRIES;
do {
timectl = wm8350_reg_read(wm8350,
WM8350_RTC_TIME_CONTROL);
} while (timectl & WM8350_RTC_STS && --retries);
if (retries == 0) {
dev_err(&pdev->dev, "failed to start: timeout\n");
return -ENODEV;
}
}
device_init_wakeup(&pdev->dev, 1);
wm_rtc->rtc = devm_rtc_device_register(&pdev->dev, "wm8350",
&wm8350_rtc_ops, THIS_MODULE);
if (IS_ERR(wm_rtc->rtc)) {
ret = PTR_ERR(wm_rtc->rtc);
dev_err(&pdev->dev, "failed to register RTC: %d\n", ret);
return ret;
}
wm8350_register_irq(wm8350, WM8350_IRQ_RTC_SEC,
wm8350_rtc_update_handler, 0,
"RTC Seconds", wm8350);
wm8350_mask_irq(wm8350, WM8350_IRQ_RTC_SEC);
wm8350_register_irq(wm8350, WM8350_IRQ_RTC_ALM,
wm8350_rtc_alarm_handler, 0,
"RTC Alarm", wm8350);
return 0;
}
static int wm8350_rtc_remove(struct platform_device *pdev)
{
struct wm8350 *wm8350 = platform_get_drvdata(pdev);
wm8350_free_irq(wm8350, WM8350_IRQ_RTC_SEC, wm8350);
wm8350_free_irq(wm8350, WM8350_IRQ_RTC_ALM, wm8350);
return 0;
}
static SIMPLE_DEV_PM_OPS(wm8350_rtc_pm_ops, wm8350_rtc_suspend,
wm8350_rtc_resume);
static struct platform_driver wm8350_rtc_driver = {
.probe = wm8350_rtc_probe,
.remove = wm8350_rtc_remove,
.driver = {
.name = "wm8350-rtc",
.pm = &wm8350_rtc_pm_ops,
},
};
module_platform_driver(wm8350_rtc_driver);
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("RTC driver for the WM8350");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm8350-rtc");
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