linux/drivers/rtc/rtc-tps65910.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* rtc-tps65910.c -- TPS65910 Real Time Clock interface
*
* Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
* Author: Venu Byravarasu <vbyravarasu@nvidia.com>
*
* Based on original TI driver rtc-twl.c
* Copyright (C) 2007 MontaVista Software, Inc
* Author: Alexandre Rusev <source@mvista.com>
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/math64.h>
#include <linux/property.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/mfd/tps65910.h>
struct tps65910_rtc {
struct rtc_device *rtc;
int irq;
};
/* Total number of RTC registers needed to set time*/
#define NUM_TIME_REGS (TPS65910_YEARS - TPS65910_SECONDS + 1)
/* Total number of RTC registers needed to set compensation registers */
#define NUM_COMP_REGS (TPS65910_RTC_COMP_MSB - TPS65910_RTC_COMP_LSB + 1)
/* Min and max values supported with 'offset' interface (swapped sign) */
#define MIN_OFFSET (-277761)
#define MAX_OFFSET (277778)
/* Number of ticks per hour */
#define TICKS_PER_HOUR (32768 * 3600)
/* Multiplier for ppb conversions */
#define PPB_MULT (1000000000LL)
static int tps65910_rtc_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct tps65910 *tps = dev_get_drvdata(dev->parent);
u8 val = 0;
if (enabled)
val = TPS65910_RTC_INTERRUPTS_IT_ALARM;
return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, val);
}
/*
* Gets current tps65910 RTC time and date parameters.
*
* The RTC's time/alarm representation is not what gmtime(3) requires
* Linux to use:
*
* - Months are 1..12 vs Linux 0-11
* - Years are 0..99 vs Linux 1900..N (we assume 21st century)
*/
static int tps65910_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
unsigned char rtc_data[NUM_TIME_REGS];
struct tps65910 *tps = dev_get_drvdata(dev->parent);
int ret;
/* Copy RTC counting registers to static registers or latches */
ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
TPS65910_RTC_CTRL_GET_TIME, TPS65910_RTC_CTRL_GET_TIME);
if (ret < 0) {
dev_err(dev, "RTC CTRL reg update failed with err:%d\n", ret);
return ret;
}
ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, rtc_data,
NUM_TIME_REGS);
if (ret < 0) {
dev_err(dev, "reading from RTC failed with err:%d\n", ret);
return ret;
}
tm->tm_sec = bcd2bin(rtc_data[0]);
tm->tm_min = bcd2bin(rtc_data[1]);
tm->tm_hour = bcd2bin(rtc_data[2]);
tm->tm_mday = bcd2bin(rtc_data[3]);
tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
tm->tm_year = bcd2bin(rtc_data[5]) + 100;
return ret;
}
static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
unsigned char rtc_data[NUM_TIME_REGS];
struct tps65910 *tps = dev_get_drvdata(dev->parent);
int ret;
rtc_data[0] = bin2bcd(tm->tm_sec);
rtc_data[1] = bin2bcd(tm->tm_min);
rtc_data[2] = bin2bcd(tm->tm_hour);
rtc_data[3] = bin2bcd(tm->tm_mday);
rtc_data[4] = bin2bcd(tm->tm_mon + 1);
rtc_data[5] = bin2bcd(tm->tm_year - 100);
/* Stop RTC while updating the RTC time registers */
ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
TPS65910_RTC_CTRL_STOP_RTC, 0);
if (ret < 0) {
dev_err(dev, "RTC stop failed with err:%d\n", ret);
return ret;
}
/* update all the time registers in one shot */
ret = regmap_bulk_write(tps->regmap, TPS65910_SECONDS, rtc_data,
NUM_TIME_REGS);
if (ret < 0) {
dev_err(dev, "rtc_set_time error %d\n", ret);
return ret;
}
/* Start back RTC */
ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
TPS65910_RTC_CTRL_STOP_RTC, 1);
if (ret < 0)
dev_err(dev, "RTC start failed with err:%d\n", ret);
return ret;
}
/*
* Gets current tps65910 RTC alarm time.
*/
static int tps65910_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
unsigned char alarm_data[NUM_TIME_REGS];
u32 int_val;
struct tps65910 *tps = dev_get_drvdata(dev->parent);
int ret;
ret = regmap_bulk_read(tps->regmap, TPS65910_ALARM_SECONDS, alarm_data,
NUM_TIME_REGS);
if (ret < 0) {
dev_err(dev, "rtc_read_alarm error %d\n", ret);
return ret;
}
alm->time.tm_sec = bcd2bin(alarm_data[0]);
alm->time.tm_min = bcd2bin(alarm_data[1]);
alm->time.tm_hour = bcd2bin(alarm_data[2]);
alm->time.tm_mday = bcd2bin(alarm_data[3]);
alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;
ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS, &int_val);
if (ret < 0)
return ret;
if (int_val & TPS65910_RTC_INTERRUPTS_IT_ALARM)
alm->enabled = 1;
return ret;
}
static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
unsigned char alarm_data[NUM_TIME_REGS];
struct tps65910 *tps = dev_get_drvdata(dev->parent);
int ret;
ret = tps65910_rtc_alarm_irq_enable(dev, 0);
if (ret)
return ret;
alarm_data[0] = bin2bcd(alm->time.tm_sec);
alarm_data[1] = bin2bcd(alm->time.tm_min);
alarm_data[2] = bin2bcd(alm->time.tm_hour);
alarm_data[3] = bin2bcd(alm->time.tm_mday);
alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
/* update all the alarm registers in one shot */
ret = regmap_bulk_write(tps->regmap, TPS65910_ALARM_SECONDS,
alarm_data, NUM_TIME_REGS);
if (ret) {
dev_err(dev, "rtc_set_alarm error %d\n", ret);
return ret;
}
if (alm->enabled)
ret = tps65910_rtc_alarm_irq_enable(dev, 1);
return ret;
}
static int tps65910_rtc_set_calibration(struct device *dev, int calibration)
{
unsigned char comp_data[NUM_COMP_REGS];
struct tps65910 *tps = dev_get_drvdata(dev->parent);
s16 value;
int ret;
/*
* TPS65910 uses two's complement 16 bit value for compensation for RTC
* crystal inaccuracies. One time every hour when seconds counter
* increments from 0 to 1 compensation value will be added to internal
* RTC counter value.
*
* Compensation value 0x7FFF is prohibited value.
*
* Valid range for compensation value: [-32768 .. 32766]
*/
if ((calibration < -32768) || (calibration > 32766)) {
dev_err(dev, "RTC calibration value out of range: %d\n",
calibration);
return -EINVAL;
}
value = (s16)calibration;
comp_data[0] = (u16)value & 0xFF;
comp_data[1] = ((u16)value >> 8) & 0xFF;
/* Update all the compensation registers in one shot */
ret = regmap_bulk_write(tps->regmap, TPS65910_RTC_COMP_LSB,
comp_data, NUM_COMP_REGS);
if (ret < 0) {
dev_err(dev, "rtc_set_calibration error: %d\n", ret);
return ret;
}
/* Enable automatic compensation */
ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
TPS65910_RTC_CTRL_AUTO_COMP, TPS65910_RTC_CTRL_AUTO_COMP);
if (ret < 0)
dev_err(dev, "auto_comp enable failed with error: %d\n", ret);
return ret;
}
static int tps65910_rtc_get_calibration(struct device *dev, int *calibration)
{
unsigned char comp_data[NUM_COMP_REGS];
struct tps65910 *tps = dev_get_drvdata(dev->parent);
unsigned int ctrl;
u16 value;
int ret;
ret = regmap_read(tps->regmap, TPS65910_RTC_CTRL, &ctrl);
if (ret < 0)
return ret;
/* If automatic compensation is not enabled report back zero */
if (!(ctrl & TPS65910_RTC_CTRL_AUTO_COMP)) {
*calibration = 0;
return 0;
}
ret = regmap_bulk_read(tps->regmap, TPS65910_RTC_COMP_LSB, comp_data,
NUM_COMP_REGS);
if (ret < 0) {
dev_err(dev, "rtc_get_calibration error: %d\n", ret);
return ret;
}
value = (u16)comp_data[0] | ((u16)comp_data[1] << 8);
*calibration = (s16)value;
return 0;
}
static int tps65910_read_offset(struct device *dev, long *offset)
{
int calibration;
s64 tmp;
int ret;
ret = tps65910_rtc_get_calibration(dev, &calibration);
if (ret < 0)
return ret;
/* Convert from RTC calibration register format to ppb format */
tmp = calibration * (s64)PPB_MULT;
if (tmp < 0)
tmp -= TICKS_PER_HOUR / 2LL;
else
tmp += TICKS_PER_HOUR / 2LL;
tmp = div_s64(tmp, TICKS_PER_HOUR);
/* Offset value operates in negative way, so swap sign */
*offset = (long)-tmp;
return 0;
}
static int tps65910_set_offset(struct device *dev, long offset)
{
int calibration;
s64 tmp;
int ret;
/* Make sure offset value is within supported range */
if (offset < MIN_OFFSET || offset > MAX_OFFSET)
return -ERANGE;
/* Convert from ppb format to RTC calibration register format */
tmp = offset * (s64)TICKS_PER_HOUR;
if (tmp < 0)
tmp -= PPB_MULT / 2LL;
else
tmp += PPB_MULT / 2LL;
tmp = div_s64(tmp, PPB_MULT);
/* Offset value operates in negative way, so swap sign */
calibration = (int)-tmp;
ret = tps65910_rtc_set_calibration(dev, calibration);
return ret;
}
static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc)
{
struct device *dev = rtc;
unsigned long events = 0;
struct tps65910 *tps = dev_get_drvdata(dev->parent);
struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
int ret;
u32 rtc_reg;
ret = regmap_read(tps->regmap, TPS65910_RTC_STATUS, &rtc_reg);
if (ret)
return IRQ_NONE;
if (rtc_reg & TPS65910_RTC_STATUS_ALARM)
events = RTC_IRQF | RTC_AF;
ret = regmap_write(tps->regmap, TPS65910_RTC_STATUS, rtc_reg);
if (ret)
return IRQ_NONE;
/* Notify RTC core on event */
rtc_update_irq(tps_rtc->rtc, 1, events);
return IRQ_HANDLED;
}
static const struct rtc_class_ops tps65910_rtc_ops = {
.read_time = tps65910_rtc_read_time,
.set_time = tps65910_rtc_set_time,
.read_alarm = tps65910_rtc_read_alarm,
.set_alarm = tps65910_rtc_set_alarm,
.alarm_irq_enable = tps65910_rtc_alarm_irq_enable,
.read_offset = tps65910_read_offset,
.set_offset = tps65910_set_offset,
};
static int tps65910_rtc_probe(struct platform_device *pdev)
{
struct tps65910 *tps65910 = NULL;
struct tps65910_rtc *tps_rtc = NULL;
int ret;
int irq;
u32 rtc_reg;
tps65910 = dev_get_drvdata(pdev->dev.parent);
tps_rtc = devm_kzalloc(&pdev->dev, sizeof(struct tps65910_rtc),
GFP_KERNEL);
if (!tps_rtc)
return -ENOMEM;
tps_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(tps_rtc->rtc))
return PTR_ERR(tps_rtc->rtc);
/* Clear pending interrupts */
ret = regmap_read(tps65910->regmap, TPS65910_RTC_STATUS, &rtc_reg);
if (ret < 0)
return ret;
ret = regmap_write(tps65910->regmap, TPS65910_RTC_STATUS, rtc_reg);
if (ret < 0)
return ret;
dev_dbg(&pdev->dev, "Enabling rtc-tps65910.\n");
/* Enable RTC digital power domain */
ret = regmap_update_bits(tps65910->regmap, TPS65910_DEVCTRL,
DEVCTRL_RTC_PWDN_MASK, 0 << DEVCTRL_RTC_PWDN_SHIFT);
if (ret < 0)
return ret;
rtc_reg = TPS65910_RTC_CTRL_STOP_RTC;
ret = regmap_write(tps65910->regmap, TPS65910_RTC_CTRL, rtc_reg);
if (ret < 0)
return ret;
platform_set_drvdata(pdev, tps_rtc);
irq = platform_get_irq(pdev, 0);
if (irq <= 0) {
dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n",
irq);
return -ENXIO;
}
ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
tps65910_rtc_interrupt, IRQF_TRIGGER_LOW,
dev_name(&pdev->dev), &pdev->dev);
if (ret < 0)
irq = -1;
tps_rtc->irq = irq;
if (irq != -1) {
if (device_property_present(tps65910->dev, "wakeup-source"))
device_init_wakeup(&pdev->dev, 1);
else
device_set_wakeup_capable(&pdev->dev, 1);
} else {
clear_bit(RTC_FEATURE_ALARM, tps_rtc->rtc->features);
}
tps_rtc->rtc->ops = &tps65910_rtc_ops;
tps_rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
tps_rtc->rtc->range_max = RTC_TIMESTAMP_END_2099;
return devm_rtc_register_device(tps_rtc->rtc);
}
#ifdef CONFIG_PM_SLEEP
static int tps65910_rtc_suspend(struct device *dev)
{
struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
enable_irq_wake(tps_rtc->irq);
return 0;
}
static int tps65910_rtc_resume(struct device *dev)
{
struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
disable_irq_wake(tps_rtc->irq);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(tps65910_rtc_pm_ops, tps65910_rtc_suspend,
tps65910_rtc_resume);
static struct platform_driver tps65910_rtc_driver = {
.probe = tps65910_rtc_probe,
.driver = {
.name = "tps65910-rtc",
.pm = &tps65910_rtc_pm_ops,
},
};
module_platform_driver(tps65910_rtc_driver);
MODULE_ALIAS("platform:rtc-tps65910");
MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
MODULE_LICENSE("GPL");