- 根目录:
- drivers
- rtc
- rtc-pm8xxx.c
/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/rtc.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/mfd/pm8xxx/core.h>
#include <linux/mfd/pm8xxx/rtc.h>
/* RTC Register offsets from RTC CTRL REG */
#define PM8XXX_ALARM_CTRL_OFFSET 0x01
#define PM8XXX_RTC_WRITE_OFFSET 0x02
#define PM8XXX_RTC_READ_OFFSET 0x06
#define PM8XXX_ALARM_RW_OFFSET 0x0A
/* RTC_CTRL register bit fields */
#define PM8xxx_RTC_ENABLE BIT(7)
#define PM8xxx_RTC_ALARM_ENABLE BIT(1)
#define PM8xxx_RTC_ALARM_CLEAR BIT(0)
#define NUM_8_BIT_RTC_REGS 0x4
/**
* struct pm8xxx_rtc - rtc driver internal structure
* @rtc: rtc device for this driver.
* @rtc_alarm_irq: rtc alarm irq number.
* @rtc_base: address of rtc control register.
* @rtc_read_base: base address of read registers.
* @rtc_write_base: base address of write registers.
* @alarm_rw_base: base address of alarm registers.
* @ctrl_reg: rtc control register.
* @rtc_dev: device structure.
* @ctrl_reg_lock: spinlock protecting access to ctrl_reg.
*/
struct pm8xxx_rtc {
struct rtc_device *rtc;
int rtc_alarm_irq;
int rtc_base;
int rtc_read_base;
int rtc_write_base;
int alarm_rw_base;
u8 ctrl_reg;
struct device *rtc_dev;
spinlock_t ctrl_reg_lock;
};
/*
* The RTC registers need to be read/written one byte at a time. This is a
* hardware limitation.
*/
static int pm8xxx_read_wrapper(struct pm8xxx_rtc *rtc_dd, u8 *rtc_val,
int base, int count)
{
int i, rc;
struct device *parent = rtc_dd->rtc_dev->parent;
for (i = 0; i < count; i++) {
rc = pm8xxx_readb(parent, base + i, &rtc_val[i]);
if (rc < 0) {
dev_err(rtc_dd->rtc_dev, "PMIC read failed\n");
return rc;
}
}
return 0;
}
static int pm8xxx_write_wrapper(struct pm8xxx_rtc *rtc_dd, u8 *rtc_val,
int base, int count)
{
int i, rc;
struct device *parent = rtc_dd->rtc_dev->parent;
for (i = 0; i < count; i++) {
rc = pm8xxx_writeb(parent, base + i, rtc_val[i]);
if (rc < 0) {
dev_err(rtc_dd->rtc_dev, "PMIC write failed\n");
return rc;
}
}
return 0;
}
/*
* Steps to write the RTC registers.
* 1. Disable alarm if enabled.
* 2. Write 0x00 to LSB.
* 3. Write Byte[1], Byte[2], Byte[3] then Byte[0].
* 4. Enable alarm if disabled in step 1.
*/
static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
int rc, i;
unsigned long secs, irq_flags;
u8 value[NUM_8_BIT_RTC_REGS], reg = 0, alarm_enabled = 0, ctrl_reg;
struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
rtc_tm_to_time(tm, &secs);
for (i = 0; i < NUM_8_BIT_RTC_REGS; i++) {
value[i] = secs & 0xFF;
secs >>= 8;
}
dev_dbg(dev, "Seconds value to be written to RTC = %lu\n", secs);
spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
ctrl_reg = rtc_dd->ctrl_reg;
if (ctrl_reg & PM8xxx_RTC_ALARM_ENABLE) {
alarm_enabled = 1;
ctrl_reg &= ~PM8xxx_RTC_ALARM_ENABLE;
rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
1);
if (rc < 0) {
dev_err(dev, "Write to RTC control register "
"failed\n");
goto rtc_rw_fail;
}
rtc_dd->ctrl_reg = ctrl_reg;
} else
spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
/* Write 0 to Byte[0] */
reg = 0;
rc = pm8xxx_write_wrapper(rtc_dd, ®, rtc_dd->rtc_write_base, 1);
if (rc < 0) {
dev_err(dev, "Write to RTC write data register failed\n");
goto rtc_rw_fail;
}
/* Write Byte[1], Byte[2], Byte[3] */
rc = pm8xxx_write_wrapper(rtc_dd, value + 1,
rtc_dd->rtc_write_base + 1, 3);
if (rc < 0) {
dev_err(dev, "Write to RTC write data register failed\n");
goto rtc_rw_fail;
}
/* Write Byte[0] */
rc = pm8xxx_write_wrapper(rtc_dd, value, rtc_dd->rtc_write_base, 1);
if (rc < 0) {
dev_err(dev, "Write to RTC write data register failed\n");
goto rtc_rw_fail;
}
if (alarm_enabled) {
ctrl_reg |= PM8xxx_RTC_ALARM_ENABLE;
rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
1);
if (rc < 0) {
dev_err(dev, "Write to RTC control register "
"failed\n");
goto rtc_rw_fail;
}
rtc_dd->ctrl_reg = ctrl_reg;
}
rtc_rw_fail:
if (alarm_enabled)
spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
return rc;
}
static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
int rc;
u8 value[NUM_8_BIT_RTC_REGS], reg;
unsigned long secs;
struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
rc = pm8xxx_read_wrapper(rtc_dd, value, rtc_dd->rtc_read_base,
NUM_8_BIT_RTC_REGS);
if (rc < 0) {
dev_err(dev, "RTC read data register failed\n");
return rc;
}
/*
* Read the LSB again and check if there has been a carry over.
* If there is, redo the read operation.
*/
rc = pm8xxx_read_wrapper(rtc_dd, ®, rtc_dd->rtc_read_base, 1);
if (rc < 0) {
dev_err(dev, "RTC read data register failed\n");
return rc;
}
if (unlikely(reg < value[0])) {
rc = pm8xxx_read_wrapper(rtc_dd, value,
rtc_dd->rtc_read_base, NUM_8_BIT_RTC_REGS);
if (rc < 0) {
dev_err(dev, "RTC read data register failed\n");
return rc;
}
}
secs = value[0] | (value[1] << 8) | (value[2] << 16) | (value[3] << 24);
rtc_time_to_tm(secs, tm);
rc = rtc_valid_tm(tm);
if (rc < 0) {
dev_err(dev, "Invalid time read from RTC\n");
return rc;
}
dev_dbg(dev, "secs = %lu, h:m:s == %d:%d:%d, d/m/y = %d/%d/%d\n",
secs, tm->tm_hour, tm->tm_min, tm->tm_sec,
tm->tm_mday, tm->tm_mon, tm->tm_year);
return 0;
}
static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
int rc, i;
u8 value[NUM_8_BIT_RTC_REGS], ctrl_reg;
unsigned long secs, irq_flags;
struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
rtc_tm_to_time(&alarm->time, &secs);
for (i = 0; i < NUM_8_BIT_RTC_REGS; i++) {
value[i] = secs & 0xFF;
secs >>= 8;
}
spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
rc = pm8xxx_write_wrapper(rtc_dd, value, rtc_dd->alarm_rw_base,
NUM_8_BIT_RTC_REGS);
if (rc < 0) {
dev_err(dev, "Write to RTC ALARM register failed\n");
goto rtc_rw_fail;
}
ctrl_reg = rtc_dd->ctrl_reg;
ctrl_reg = alarm->enabled ? (ctrl_reg | PM8xxx_RTC_ALARM_ENABLE) :
(ctrl_reg & ~PM8xxx_RTC_ALARM_ENABLE);
rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
if (rc < 0) {
dev_err(dev, "Write to RTC control register failed\n");
goto rtc_rw_fail;
}
rtc_dd->ctrl_reg = ctrl_reg;
dev_dbg(dev, "Alarm Set for h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
alarm->time.tm_hour, alarm->time.tm_min,
alarm->time.tm_sec, alarm->time.tm_mday,
alarm->time.tm_mon, alarm->time.tm_year);
rtc_rw_fail:
spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
return rc;
}
static int pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
int rc;
u8 value[NUM_8_BIT_RTC_REGS];
unsigned long secs;
struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
rc = pm8xxx_read_wrapper(rtc_dd, value, rtc_dd->alarm_rw_base,
NUM_8_BIT_RTC_REGS);
if (rc < 0) {
dev_err(dev, "RTC alarm time read failed\n");
return rc;
}
secs = value[0] | (value[1] << 8) | (value[2] << 16) | (value[3] << 24);
rtc_time_to_tm(secs, &alarm->time);
rc = rtc_valid_tm(&alarm->time);
if (rc < 0) {
dev_err(dev, "Invalid alarm time read from RTC\n");
return rc;
}
dev_dbg(dev, "Alarm set for - h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
alarm->time.tm_hour, alarm->time.tm_min,
alarm->time.tm_sec, alarm->time.tm_mday,
alarm->time.tm_mon, alarm->time.tm_year);
return 0;
}
static int pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
{
int rc;
unsigned long irq_flags;
struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
u8 ctrl_reg;
spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
ctrl_reg = rtc_dd->ctrl_reg;
ctrl_reg = (enable) ? (ctrl_reg | PM8xxx_RTC_ALARM_ENABLE) :
(ctrl_reg & ~PM8xxx_RTC_ALARM_ENABLE);
rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
if (rc < 0) {
dev_err(dev, "Write to RTC control register failed\n");
goto rtc_rw_fail;
}
rtc_dd->ctrl_reg = ctrl_reg;
rtc_rw_fail:
spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
return rc;
}
static struct rtc_class_ops pm8xxx_rtc_ops = {
.read_time = pm8xxx_rtc_read_time,
.set_alarm = pm8xxx_rtc_set_alarm,
.read_alarm = pm8xxx_rtc_read_alarm,
.alarm_irq_enable = pm8xxx_rtc_alarm_irq_enable,
};
static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
{
struct pm8xxx_rtc *rtc_dd = dev_id;
u8 ctrl_reg;
int rc;
unsigned long irq_flags;
rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF);
spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
/* Clear the alarm enable bit */
ctrl_reg = rtc_dd->ctrl_reg;
ctrl_reg &= ~PM8xxx_RTC_ALARM_ENABLE;
rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
if (rc < 0) {
spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
dev_err(rtc_dd->rtc_dev, "Write to RTC control register "
"failed\n");
goto rtc_alarm_handled;
}
rtc_dd->ctrl_reg = ctrl_reg;
spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
/* Clear RTC alarm register */
rc = pm8xxx_read_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base +
PM8XXX_ALARM_CTRL_OFFSET, 1);
if (rc < 0) {
dev_err(rtc_dd->rtc_dev, "RTC Alarm control register read "
"failed\n");
goto rtc_alarm_handled;
}
ctrl_reg &= ~PM8xxx_RTC_ALARM_CLEAR;
rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base +
PM8XXX_ALARM_CTRL_OFFSET, 1);
if (rc < 0)
dev_err(rtc_dd->rtc_dev, "Write to RTC Alarm control register"
" failed\n");
rtc_alarm_handled:
return IRQ_HANDLED;
}
static int pm8xxx_rtc_probe(struct platform_device *pdev)
{
int rc;
u8 ctrl_reg;
bool rtc_write_enable = false;
struct pm8xxx_rtc *rtc_dd;
struct resource *rtc_resource;
const struct pm8xxx_rtc_platform_data *pdata =
dev_get_platdata(&pdev->dev);
if (pdata != NULL)
rtc_write_enable = pdata->rtc_write_enable;
rtc_dd = devm_kzalloc(&pdev->dev, sizeof(*rtc_dd), GFP_KERNEL);
if (rtc_dd == NULL) {
dev_err(&pdev->dev, "Unable to allocate memory!\n");
return -ENOMEM;
}
/* Initialise spinlock to protect RTC control register */
spin_lock_init(&rtc_dd->ctrl_reg_lock);
rtc_dd->rtc_alarm_irq = platform_get_irq(pdev, 0);
if (rtc_dd->rtc_alarm_irq < 0) {
dev_err(&pdev->dev, "Alarm IRQ resource absent!\n");
return -ENXIO;
}
rtc_resource = platform_get_resource_byname(pdev, IORESOURCE_IO,
"pmic_rtc_base");
if (!(rtc_resource && rtc_resource->start)) {
dev_err(&pdev->dev, "RTC IO resource absent!\n");
return -ENXIO;
}
rtc_dd->rtc_base = rtc_resource->start;
/* Setup RTC register addresses */
rtc_dd->rtc_write_base = rtc_dd->rtc_base + PM8XXX_RTC_WRITE_OFFSET;
rtc_dd->rtc_read_base = rtc_dd->rtc_base + PM8XXX_RTC_READ_OFFSET;
rtc_dd->alarm_rw_base = rtc_dd->rtc_base + PM8XXX_ALARM_RW_OFFSET;
rtc_dd->rtc_dev = &pdev->dev;
/* Check if the RTC is on, else turn it on */
rc = pm8xxx_read_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base, 1);
if (rc < 0) {
dev_err(&pdev->dev, "RTC control register read failed!\n");
return rc;
}
if (!(ctrl_reg & PM8xxx_RTC_ENABLE)) {
ctrl_reg |= PM8xxx_RTC_ENABLE;
rc = pm8xxx_write_wrapper(rtc_dd, &ctrl_reg, rtc_dd->rtc_base,
1);
if (rc < 0) {
dev_err(&pdev->dev, "Write to RTC control register "
"failed\n");
return rc;
}
}
rtc_dd->ctrl_reg = ctrl_reg;
if (rtc_write_enable == true)
pm8xxx_rtc_ops.set_time = pm8xxx_rtc_set_time;
platform_set_drvdata(pdev, rtc_dd);
/* Register the RTC device */
rtc_dd->rtc = devm_rtc_device_register(&pdev->dev, "pm8xxx_rtc",
&pm8xxx_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc_dd->rtc)) {
dev_err(&pdev->dev, "%s: RTC registration failed (%ld)\n",
__func__, PTR_ERR(rtc_dd->rtc));
return PTR_ERR(rtc_dd->rtc);
}
/* Request the alarm IRQ */
rc = request_any_context_irq(rtc_dd->rtc_alarm_irq,
pm8xxx_alarm_trigger, IRQF_TRIGGER_RISING,
"pm8xxx_rtc_alarm", rtc_dd);
if (rc < 0) {
dev_err(&pdev->dev, "Request IRQ failed (%d)\n", rc);
return rc;
}
device_init_wakeup(&pdev->dev, 1);
dev_dbg(&pdev->dev, "Probe success !!\n");
return 0;
}
static int pm8xxx_rtc_remove(struct platform_device *pdev)
{
struct pm8xxx_rtc *rtc_dd = platform_get_drvdata(pdev);
device_init_wakeup(&pdev->dev, 0);
free_irq(rtc_dd->rtc_alarm_irq, rtc_dd);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int pm8xxx_rtc_resume(struct device *dev)
{
struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
disable_irq_wake(rtc_dd->rtc_alarm_irq);
return 0;
}
static int pm8xxx_rtc_suspend(struct device *dev)
{
struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
enable_irq_wake(rtc_dd->rtc_alarm_irq);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(pm8xxx_rtc_pm_ops, pm8xxx_rtc_suspend, pm8xxx_rtc_resume);
static struct platform_driver pm8xxx_rtc_driver = {
.probe = pm8xxx_rtc_probe,
.remove = pm8xxx_rtc_remove,
.driver = {
.name = PM8XXX_RTC_DEV_NAME,
.owner = THIS_MODULE,
.pm = &pm8xxx_rtc_pm_ops,
},
};
module_platform_driver(pm8xxx_rtc_driver);
MODULE_ALIAS("platform:rtc-pm8xxx");
MODULE_DESCRIPTION("PMIC8xxx RTC driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Anirudh Ghayal <aghayal@codeaurora.org>");