- 根目录:
- drivers
- rtc
- rtc-palmas.c
/*
* rtc-palmas.c -- Palmas Real Time Clock driver.
* RTC driver for TI Palma series devices like TPS65913,
* TPS65914 power management IC.
*
* Copyright (c) 2012, NVIDIA Corporation.
*
* Author: Laxman Dewangan <ldewangan@nvidia.com>
*
* 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 version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
* whether express or implied; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
* 02111-1307, USA
*/
#include <linux/bcd.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mfd/palmas.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/rtc.h>
#include <linux/types.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
struct palmas_rtc {
struct rtc_device *rtc;
struct device *dev;
unsigned int irq;
};
/* Total number of RTC registers needed to set time*/
#define PALMAS_NUM_TIME_REGS (PALMAS_YEARS_REG - PALMAS_SECONDS_REG + 1)
/*
* Special bin2bcd mapping to deal with bcd storage of year.
*
* 0-69 -> 0xD0
* 70-99 (1970 - 1999) -> 0xD0 - 0xF9 (correctly rolls to 0x00)
* 100-199 (2000 - 2099) -> 0x00 - 0x99 (does not roll to 0xA0 :-( )
* 200-229 (2100 - 2129) -> 0xA0 - 0xC9 (really for completeness)
* 230- -> 0xC9
*
* Confirmed: the only transition that does not work correctly for this rtc
* clock is the transition from 2099 to 2100, it proceeds to 2000. We will
* accept this issue since the clock retains and transitions the year correctly
* in all other conditions.
*/
static unsigned char year_bin2bcd(int val)
{
if (val < 70)
return 0xD0;
if (val < 100)
return bin2bcd(val - 20) | 0x80; /* KISS leverage of bin2bcd */
if (val >= 230)
return 0xC9;
if (val >= 200)
return bin2bcd(val - 180) | 0x80;
return bin2bcd(val - 100);
}
static int year_bcd2bin(unsigned char val)
{
if (val >= 0xD0)
return bcd2bin(val & 0x7F) + 20;
if (val >= 0xA0)
return bcd2bin(val & 0x7F) + 180;
return bcd2bin(val) + 100;
}
static int palmas_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
struct palmas *palmas = dev_get_drvdata(dev->parent);
int ret;
/* Copy RTC counting registers to static registers or latches */
ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
PALMAS_RTC_CTRL_REG_GET_TIME, PALMAS_RTC_CTRL_REG_GET_TIME);
if (ret < 0) {
dev_err(dev, "RTC CTRL reg update failed, err: %d\n", ret);
return ret;
}
ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
rtc_data, PALMAS_NUM_TIME_REGS);
if (ret < 0) {
dev_err(dev, "RTC_SECONDS reg read failed, 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 = year_bcd2bin(rtc_data[5]);
return ret;
}
static int palmas_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
struct palmas *palmas = 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] = year_bin2bcd(tm->tm_year);
/* Stop RTC while updating the RTC time registers */
ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
PALMAS_RTC_CTRL_REG_STOP_RTC, 0);
if (ret < 0) {
dev_err(dev, "RTC stop failed, err = %d\n", ret);
return ret;
}
ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
rtc_data, PALMAS_NUM_TIME_REGS);
if (ret < 0) {
dev_err(dev, "RTC_SECONDS reg write failed, err = %d\n", ret);
return ret;
}
/* Start back RTC */
ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
PALMAS_RTC_CTRL_REG_STOP_RTC, PALMAS_RTC_CTRL_REG_STOP_RTC);
if (ret < 0)
dev_err(dev, "RTC start failed, err = %d\n", ret);
return ret;
}
static int palmas_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
{
struct palmas *palmas = dev_get_drvdata(dev->parent);
u8 val;
val = enabled ? PALMAS_RTC_INTERRUPTS_REG_IT_ALARM : 0;
return palmas_write(palmas, PALMAS_RTC_BASE,
PALMAS_RTC_INTERRUPTS_REG, val);
}
static int palmas_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
u32 int_val;
struct palmas *palmas = dev_get_drvdata(dev->parent);
int ret;
ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE,
PALMAS_ALARM_SECONDS_REG,
alarm_data, PALMAS_NUM_TIME_REGS);
if (ret < 0) {
dev_err(dev, "RTC_ALARM_SECONDS read failed, err = %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 = year_bcd2bin(alarm_data[5]);
ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_INTERRUPTS_REG,
&int_val);
if (ret < 0) {
dev_err(dev, "RTC_INTERRUPTS reg read failed, err = %d\n", ret);
return ret;
}
if (int_val & PALMAS_RTC_INTERRUPTS_REG_IT_ALARM)
alm->enabled = 1;
return ret;
}
static int palmas_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
struct palmas *palmas = dev_get_drvdata(dev->parent);
int ret;
ret = palmas_rtc_alarm_irq_enable(dev, 0);
if (ret < 0) {
dev_err(dev, "Disable RTC alarm failed\n");
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] = year_bin2bcd(alm->time.tm_year);
ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE,
PALMAS_ALARM_SECONDS_REG, alarm_data, PALMAS_NUM_TIME_REGS);
if (ret < 0) {
dev_err(dev, "ALARM_SECONDS_REG write failed, err = %d\n", ret);
return ret;
}
if (alm->enabled)
ret = palmas_rtc_alarm_irq_enable(dev, 1);
return ret;
}
static int palmas_clear_interrupts(struct device *dev)
{
struct palmas *palmas = dev_get_drvdata(dev->parent);
unsigned int rtc_reg;
int ret;
ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
&rtc_reg);
if (ret < 0) {
dev_err(dev, "RTC_STATUS read failed, err = %d\n", ret);
return ret;
}
ret = palmas_write(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
rtc_reg);
if (ret < 0) {
dev_err(dev, "RTC_STATUS write failed, err = %d\n", ret);
return ret;
}
return 0;
}
static irqreturn_t palmas_rtc_interrupt(int irq, void *context)
{
struct palmas_rtc *palmas_rtc = context;
struct device *dev = palmas_rtc->dev;
int ret;
ret = palmas_clear_interrupts(dev);
if (ret < 0) {
dev_err(dev, "RTC interrupt clear failed, err = %d\n", ret);
return IRQ_NONE;
}
rtc_update_irq(palmas_rtc->rtc, 1, RTC_IRQF | RTC_AF);
return IRQ_HANDLED;
}
static struct rtc_class_ops palmas_rtc_ops = {
.read_time = palmas_rtc_read_time,
.set_time = palmas_rtc_set_time,
.read_alarm = palmas_rtc_read_alarm,
.set_alarm = palmas_rtc_set_alarm,
.alarm_irq_enable = palmas_rtc_alarm_irq_enable,
};
static int palmas_rtc_probe(struct platform_device *pdev)
{
struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
struct palmas_rtc *palmas_rtc = NULL;
int ret;
bool enable_bb_charging = false;
bool high_bb_charging;
if (pdev->dev.of_node) {
enable_bb_charging = of_property_read_bool(pdev->dev.of_node,
"ti,backup-battery-chargeable");
high_bb_charging = of_property_read_bool(pdev->dev.of_node,
"ti,backup-battery-charge-high-current");
}
palmas_rtc = devm_kzalloc(&pdev->dev, sizeof(struct palmas_rtc),
GFP_KERNEL);
if (!palmas_rtc)
return -ENOMEM;
/* Clear pending interrupts */
ret = palmas_clear_interrupts(&pdev->dev);
if (ret < 0) {
dev_err(&pdev->dev, "clear RTC int failed, err = %d\n", ret);
return ret;
}
palmas_rtc->dev = &pdev->dev;
platform_set_drvdata(pdev, palmas_rtc);
if (enable_bb_charging) {
unsigned reg = PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG;
if (high_bb_charging)
reg = 0;
ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
PALMAS_BACKUP_BATTERY_CTRL,
PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG, reg);
if (ret < 0) {
dev_err(&pdev->dev,
"BACKUP_BATTERY_CTRL update failed, %d\n", ret);
return ret;
}
ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
PALMAS_BACKUP_BATTERY_CTRL,
PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN,
PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN);
if (ret < 0) {
dev_err(&pdev->dev,
"BACKUP_BATTERY_CTRL update failed, %d\n", ret);
return ret;
}
}
/* Start RTC */
ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
PALMAS_RTC_CTRL_REG_STOP_RTC,
PALMAS_RTC_CTRL_REG_STOP_RTC);
if (ret < 0) {
dev_err(&pdev->dev, "RTC_CTRL write failed, err = %d\n", ret);
return ret;
}
palmas_rtc->irq = platform_get_irq(pdev, 0);
device_init_wakeup(&pdev->dev, 1);
palmas_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
&palmas_rtc_ops, THIS_MODULE);
if (IS_ERR(palmas_rtc->rtc)) {
ret = PTR_ERR(palmas_rtc->rtc);
dev_err(&pdev->dev, "RTC register failed, err = %d\n", ret);
return ret;
}
ret = devm_request_threaded_irq(&pdev->dev, palmas_rtc->irq, NULL,
palmas_rtc_interrupt,
IRQF_TRIGGER_LOW | IRQF_ONESHOT |
IRQF_EARLY_RESUME,
dev_name(&pdev->dev), palmas_rtc);
if (ret < 0) {
dev_err(&pdev->dev, "IRQ request failed, err = %d\n", ret);
return ret;
}
return 0;
}
static int palmas_rtc_remove(struct platform_device *pdev)
{
palmas_rtc_alarm_irq_enable(&pdev->dev, 0);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int palmas_rtc_suspend(struct device *dev)
{
struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
enable_irq_wake(palmas_rtc->irq);
return 0;
}
static int palmas_rtc_resume(struct device *dev)
{
struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
disable_irq_wake(palmas_rtc->irq);
return 0;
}
#endif
static const struct dev_pm_ops palmas_rtc_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(palmas_rtc_suspend, palmas_rtc_resume)
};
#ifdef CONFIG_OF
static const struct of_device_id of_palmas_rtc_match[] = {
{ .compatible = "ti,palmas-rtc"},
{ },
};
MODULE_DEVICE_TABLE(of, of_palmas_rtc_match);
#endif
static struct platform_driver palmas_rtc_driver = {
.probe = palmas_rtc_probe,
.remove = palmas_rtc_remove,
.driver = {
.owner = THIS_MODULE,
.name = "palmas-rtc",
.pm = &palmas_rtc_pm_ops,
.of_match_table = of_match_ptr(of_palmas_rtc_match),
},
};
module_platform_driver(palmas_rtc_driver);
MODULE_ALIAS("platform:palmas_rtc");
MODULE_DESCRIPTION("TI PALMAS series RTC driver");
MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_LICENSE("GPL v2");