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OpenCloudOS-Kernel/drivers/rtc/rtc-omap.c

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/*
* TI OMAP1 Real Time Clock interface for Linux
*
* Copyright (C) 2003 MontaVista Software, Inc.
* Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
*
* Copyright (C) 2006 David Brownell (new RTC framework)
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pm_runtime.h>
#include <linux/io.h>
/* The OMAP1 RTC is a year/month/day/hours/minutes/seconds BCD clock
* with century-range alarm matching, driven by the 32kHz clock.
*
* The main user-visible ways it differs from PC RTCs are by omitting
* "don't care" alarm fields and sub-second periodic IRQs, and having
* an autoadjust mechanism to calibrate to the true oscillator rate.
*
* Board-specific wiring options include using split power mode with
* RTC_OFF_NOFF used as the reset signal (so the RTC won't be reset),
* and wiring RTC_WAKE_INT (so the RTC alarm can wake the system from
* low power modes) for OMAP1 boards (OMAP-L138 has this built into
* the SoC). See the BOARD-SPECIFIC CUSTOMIZATION comment.
*/
/* RTC registers */
#define OMAP_RTC_SECONDS_REG 0x00
#define OMAP_RTC_MINUTES_REG 0x04
#define OMAP_RTC_HOURS_REG 0x08
#define OMAP_RTC_DAYS_REG 0x0C
#define OMAP_RTC_MONTHS_REG 0x10
#define OMAP_RTC_YEARS_REG 0x14
#define OMAP_RTC_WEEKS_REG 0x18
#define OMAP_RTC_ALARM_SECONDS_REG 0x20
#define OMAP_RTC_ALARM_MINUTES_REG 0x24
#define OMAP_RTC_ALARM_HOURS_REG 0x28
#define OMAP_RTC_ALARM_DAYS_REG 0x2c
#define OMAP_RTC_ALARM_MONTHS_REG 0x30
#define OMAP_RTC_ALARM_YEARS_REG 0x34
#define OMAP_RTC_CTRL_REG 0x40
#define OMAP_RTC_STATUS_REG 0x44
#define OMAP_RTC_INTERRUPTS_REG 0x48
#define OMAP_RTC_COMP_LSB_REG 0x4c
#define OMAP_RTC_COMP_MSB_REG 0x50
#define OMAP_RTC_OSC_REG 0x54
#define OMAP_RTC_KICK0_REG 0x6c
#define OMAP_RTC_KICK1_REG 0x70
#define OMAP_RTC_IRQWAKEEN 0x7c
/* OMAP_RTC_CTRL_REG bit fields: */
#define OMAP_RTC_CTRL_SPLIT BIT(7)
#define OMAP_RTC_CTRL_DISABLE BIT(6)
#define OMAP_RTC_CTRL_SET_32_COUNTER BIT(5)
#define OMAP_RTC_CTRL_TEST BIT(4)
#define OMAP_RTC_CTRL_MODE_12_24 BIT(3)
#define OMAP_RTC_CTRL_AUTO_COMP BIT(2)
#define OMAP_RTC_CTRL_ROUND_30S BIT(1)
#define OMAP_RTC_CTRL_STOP BIT(0)
/* OMAP_RTC_STATUS_REG bit fields: */
#define OMAP_RTC_STATUS_POWER_UP BIT(7)
#define OMAP_RTC_STATUS_ALARM BIT(6)
#define OMAP_RTC_STATUS_1D_EVENT BIT(5)
#define OMAP_RTC_STATUS_1H_EVENT BIT(4)
#define OMAP_RTC_STATUS_1M_EVENT BIT(3)
#define OMAP_RTC_STATUS_1S_EVENT BIT(2)
#define OMAP_RTC_STATUS_RUN BIT(1)
#define OMAP_RTC_STATUS_BUSY BIT(0)
/* OMAP_RTC_INTERRUPTS_REG bit fields: */
#define OMAP_RTC_INTERRUPTS_IT_ALARM BIT(3)
#define OMAP_RTC_INTERRUPTS_IT_TIMER BIT(2)
/* OMAP_RTC_OSC_REG bit fields: */
#define OMAP_RTC_OSC_32KCLK_EN BIT(6)
/* OMAP_RTC_IRQWAKEEN bit fields: */
#define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN BIT(1)
/* OMAP_RTC_KICKER values */
#define KICK0_VALUE 0x83e70b13
#define KICK1_VALUE 0x95a4f1e0
struct omap_rtc_device_type {
bool has_32kclk_en;
bool has_kicker;
bool has_irqwakeen;
bool has_power_up_reset;
};
struct omap_rtc {
struct rtc_device *rtc;
void __iomem *base;
int irq_alarm;
int irq_timer;
u8 interrupts_reg;
const struct omap_rtc_device_type *type;
};
static inline u8 rtc_read(struct omap_rtc *rtc, unsigned int reg)
{
return readb(rtc->base + reg);
}
static inline void rtc_write(struct omap_rtc *rtc, unsigned int reg, u8 val)
{
writeb(val, rtc->base + reg);
}
static inline void rtc_writel(struct omap_rtc *rtc, unsigned int reg, u32 val)
{
writel(val, rtc->base + reg);
}
/* we rely on the rtc framework to handle locking (rtc->ops_lock),
* so the only other requirement is that register accesses which
* require BUSY to be clear are made with IRQs locally disabled
*/
static void rtc_wait_not_busy(struct omap_rtc *rtc)
{
int count = 0;
u8 status;
/* BUSY may stay active for 1/32768 second (~30 usec) */
for (count = 0; count < 50; count++) {
status = rtc_read(rtc, OMAP_RTC_STATUS_REG);
if ((status & (u8)OMAP_RTC_STATUS_BUSY) == 0)
break;
udelay(1);
}
/* now we have ~15 usec to read/write various registers */
}
static irqreturn_t rtc_irq(int irq, void *dev_id)
{
struct omap_rtc *rtc = dev_id;
unsigned long events = 0;
u8 irq_data;
irq_data = rtc_read(rtc, OMAP_RTC_STATUS_REG);
/* alarm irq? */
if (irq_data & OMAP_RTC_STATUS_ALARM) {
rtc_write(rtc, OMAP_RTC_STATUS_REG, OMAP_RTC_STATUS_ALARM);
events |= RTC_IRQF | RTC_AF;
}
/* 1/sec periodic/update irq? */
if (irq_data & OMAP_RTC_STATUS_1S_EVENT)
events |= RTC_IRQF | RTC_UF;
rtc_update_irq(rtc->rtc, 1, events);
return IRQ_HANDLED;
}
static int omap_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct omap_rtc *rtc = dev_get_drvdata(dev);
u8 reg, irqwake_reg = 0;
local_irq_disable();
rtc_wait_not_busy(rtc);
reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
if (rtc->type->has_irqwakeen)
irqwake_reg = rtc_read(rtc, OMAP_RTC_IRQWAKEEN);
if (enabled) {
reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
irqwake_reg |= OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
} else {
reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
irqwake_reg &= ~OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
}
rtc_wait_not_busy(rtc);
rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, reg);
if (rtc->type->has_irqwakeen)
rtc_write(rtc, OMAP_RTC_IRQWAKEEN, irqwake_reg);
local_irq_enable();
return 0;
}
/* this hardware doesn't support "don't care" alarm fields */
static int tm2bcd(struct rtc_time *tm)
{
if (rtc_valid_tm(tm) != 0)
return -EINVAL;
tm->tm_sec = bin2bcd(tm->tm_sec);
tm->tm_min = bin2bcd(tm->tm_min);
tm->tm_hour = bin2bcd(tm->tm_hour);
tm->tm_mday = bin2bcd(tm->tm_mday);
tm->tm_mon = bin2bcd(tm->tm_mon + 1);
/* epoch == 1900 */
if (tm->tm_year < 100 || tm->tm_year > 199)
return -EINVAL;
tm->tm_year = bin2bcd(tm->tm_year - 100);
return 0;
}
static void bcd2tm(struct rtc_time *tm)
{
tm->tm_sec = bcd2bin(tm->tm_sec);
tm->tm_min = bcd2bin(tm->tm_min);
tm->tm_hour = bcd2bin(tm->tm_hour);
tm->tm_mday = bcd2bin(tm->tm_mday);
tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
/* epoch == 1900 */
tm->tm_year = bcd2bin(tm->tm_year) + 100;
}
static void omap_rtc_read_time_raw(struct omap_rtc *rtc, struct rtc_time *tm)
{
tm->tm_sec = rtc_read(rtc, OMAP_RTC_SECONDS_REG);
tm->tm_min = rtc_read(rtc, OMAP_RTC_MINUTES_REG);
tm->tm_hour = rtc_read(rtc, OMAP_RTC_HOURS_REG);
tm->tm_mday = rtc_read(rtc, OMAP_RTC_DAYS_REG);
tm->tm_mon = rtc_read(rtc, OMAP_RTC_MONTHS_REG);
tm->tm_year = rtc_read(rtc, OMAP_RTC_YEARS_REG);
}
static int omap_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct omap_rtc *rtc = dev_get_drvdata(dev);
/* we don't report wday/yday/isdst ... */
local_irq_disable();
rtc_wait_not_busy(rtc);
omap_rtc_read_time_raw(rtc, tm);
local_irq_enable();
bcd2tm(tm);
return 0;
}
static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct omap_rtc *rtc = dev_get_drvdata(dev);
if (tm2bcd(tm) < 0)
return -EINVAL;
local_irq_disable();
rtc_wait_not_busy(rtc);
rtc_write(rtc, OMAP_RTC_YEARS_REG, tm->tm_year);
rtc_write(rtc, OMAP_RTC_MONTHS_REG, tm->tm_mon);
rtc_write(rtc, OMAP_RTC_DAYS_REG, tm->tm_mday);
rtc_write(rtc, OMAP_RTC_HOURS_REG, tm->tm_hour);
rtc_write(rtc, OMAP_RTC_MINUTES_REG, tm->tm_min);
rtc_write(rtc, OMAP_RTC_SECONDS_REG, tm->tm_sec);
local_irq_enable();
return 0;
}
static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
struct omap_rtc *rtc = dev_get_drvdata(dev);
local_irq_disable();
rtc_wait_not_busy(rtc);
alm->time.tm_sec = rtc_read(rtc, OMAP_RTC_ALARM_SECONDS_REG);
alm->time.tm_min = rtc_read(rtc, OMAP_RTC_ALARM_MINUTES_REG);
alm->time.tm_hour = rtc_read(rtc, OMAP_RTC_ALARM_HOURS_REG);
alm->time.tm_mday = rtc_read(rtc, OMAP_RTC_ALARM_DAYS_REG);
alm->time.tm_mon = rtc_read(rtc, OMAP_RTC_ALARM_MONTHS_REG);
alm->time.tm_year = rtc_read(rtc, OMAP_RTC_ALARM_YEARS_REG);
local_irq_enable();
bcd2tm(&alm->time);
alm->enabled = !!(rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG)
& OMAP_RTC_INTERRUPTS_IT_ALARM);
return 0;
}
static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
struct omap_rtc *rtc = dev_get_drvdata(dev);
u8 reg, irqwake_reg = 0;
if (tm2bcd(&alm->time) < 0)
return -EINVAL;
local_irq_disable();
rtc_wait_not_busy(rtc);
rtc_write(rtc, OMAP_RTC_ALARM_YEARS_REG, alm->time.tm_year);
rtc_write(rtc, OMAP_RTC_ALARM_MONTHS_REG, alm->time.tm_mon);
rtc_write(rtc, OMAP_RTC_ALARM_DAYS_REG, alm->time.tm_mday);
rtc_write(rtc, OMAP_RTC_ALARM_HOURS_REG, alm->time.tm_hour);
rtc_write(rtc, OMAP_RTC_ALARM_MINUTES_REG, alm->time.tm_min);
rtc_write(rtc, OMAP_RTC_ALARM_SECONDS_REG, alm->time.tm_sec);
reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
if (rtc->type->has_irqwakeen)
irqwake_reg = rtc_read(rtc, OMAP_RTC_IRQWAKEEN);
if (alm->enabled) {
reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
irqwake_reg |= OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
} else {
reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
irqwake_reg &= ~OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN;
}
rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, reg);
if (rtc->type->has_irqwakeen)
rtc_write(rtc, OMAP_RTC_IRQWAKEEN, irqwake_reg);
local_irq_enable();
return 0;
}
static struct rtc_class_ops omap_rtc_ops = {
.read_time = omap_rtc_read_time,
.set_time = omap_rtc_set_time,
.read_alarm = omap_rtc_read_alarm,
.set_alarm = omap_rtc_set_alarm,
.alarm_irq_enable = omap_rtc_alarm_irq_enable,
};
static const struct omap_rtc_device_type omap_rtc_default_type = {
.has_power_up_reset = true,
};
static const struct omap_rtc_device_type omap_rtc_am3352_type = {
.has_32kclk_en = true,
.has_kicker = true,
.has_irqwakeen = true,
};
static const struct omap_rtc_device_type omap_rtc_da830_type = {
.has_kicker = true,
};
static const struct platform_device_id omap_rtc_id_table[] = {
{
.name = "omap_rtc",
.driver_data = (kernel_ulong_t)&omap_rtc_default_type,
}, {
.name = "am3352-rtc",
.driver_data = (kernel_ulong_t)&omap_rtc_am3352_type,
}, {
.name = "da830-rtc",
.driver_data = (kernel_ulong_t)&omap_rtc_da830_type,
}, {
/* sentinel */
}
};
MODULE_DEVICE_TABLE(platform, omap_rtc_id_table);
static const struct of_device_id omap_rtc_of_match[] = {
{
.compatible = "ti,am3352-rtc",
.data = &omap_rtc_am3352_type,
}, {
.compatible = "ti,da830-rtc",
.data = &omap_rtc_da830_type,
}, {
/* sentinel */
}
};
MODULE_DEVICE_TABLE(of, omap_rtc_of_match);
static int __init omap_rtc_probe(struct platform_device *pdev)
{
struct omap_rtc *rtc;
struct resource *res;
u8 reg, mask, new_ctrl;
const struct platform_device_id *id_entry;
const struct of_device_id *of_id;
int ret;
rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
if (!rtc)
return -ENOMEM;
of_id = of_match_device(omap_rtc_of_match, &pdev->dev);
if (of_id) {
rtc->type = of_id->data;
} else {
id_entry = platform_get_device_id(pdev);
rtc->type = (void *)id_entry->driver_data;
}
rtc->irq_timer = platform_get_irq(pdev, 0);
if (rtc->irq_timer <= 0)
return -ENOENT;
rtc->irq_alarm = platform_get_irq(pdev, 1);
if (rtc->irq_alarm <= 0)
return -ENOENT;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
rtc->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(rtc->base))
return PTR_ERR(rtc->base);
platform_set_drvdata(pdev, rtc);
/* Enable the clock/module so that we can access the registers */
pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);
if (rtc->type->has_kicker) {
rtc_writel(rtc, OMAP_RTC_KICK0_REG, KICK0_VALUE);
rtc_writel(rtc, OMAP_RTC_KICK1_REG, KICK1_VALUE);
}
/*
* disable interrupts
*
* NOTE: ALARM2 is not cleared on AM3352 if rtc_write (writeb) is used
*/
rtc_writel(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
/* enable RTC functional clock */
if (rtc->type->has_32kclk_en) {
reg = rtc_read(rtc, OMAP_RTC_OSC_REG);
rtc_writel(rtc, OMAP_RTC_OSC_REG,
reg | OMAP_RTC_OSC_32KCLK_EN);
}
/* clear old status */
reg = rtc_read(rtc, OMAP_RTC_STATUS_REG);
mask = OMAP_RTC_STATUS_ALARM;
if (rtc->type->has_power_up_reset) {
mask |= OMAP_RTC_STATUS_POWER_UP;
if (reg & OMAP_RTC_STATUS_POWER_UP)
dev_info(&pdev->dev, "RTC power up reset detected\n");
}
if (reg & mask)
rtc_write(rtc, OMAP_RTC_STATUS_REG, reg & mask);
/* On boards with split power, RTC_ON_NOFF won't reset the RTC */
reg = rtc_read(rtc, OMAP_RTC_CTRL_REG);
if (reg & (u8) OMAP_RTC_CTRL_STOP)
dev_info(&pdev->dev, "already running\n");
/* force to 24 hour mode */
new_ctrl = reg & (OMAP_RTC_CTRL_SPLIT|OMAP_RTC_CTRL_AUTO_COMP);
new_ctrl |= OMAP_RTC_CTRL_STOP;
/* BOARD-SPECIFIC CUSTOMIZATION CAN GO HERE:
*
* - Device wake-up capability setting should come through chip
* init logic. OMAP1 boards should initialize the "wakeup capable"
* flag in the platform device if the board is wired right for
* being woken up by RTC alarm. For OMAP-L138, this capability
* is built into the SoC by the "Deep Sleep" capability.
*
* - Boards wired so RTC_ON_nOFF is used as the reset signal,
* rather than nPWRON_RESET, should forcibly enable split
* power mode. (Some chip errata report that RTC_CTRL_SPLIT
* is write-only, and always reads as zero...)
*/
if (new_ctrl & (u8) OMAP_RTC_CTRL_SPLIT)
dev_info(&pdev->dev, "split power mode\n");
if (reg != new_ctrl)
rtc_write(rtc, OMAP_RTC_CTRL_REG, new_ctrl);
device_init_wakeup(&pdev->dev, true);
rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
&omap_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc->rtc)) {
ret = PTR_ERR(rtc->rtc);
goto err;
}
/* handle periodic and alarm irqs */
ret = devm_request_irq(&pdev->dev, rtc->irq_timer, rtc_irq, 0,
dev_name(&rtc->rtc->dev), rtc);
if (ret)
goto err;
if (rtc->irq_timer != rtc->irq_alarm) {
ret = devm_request_irq(&pdev->dev, rtc->irq_alarm, rtc_irq, 0,
dev_name(&rtc->rtc->dev), rtc);
if (ret)
goto err;
}
return 0;
err:
device_init_wakeup(&pdev->dev, false);
if (rtc->type->has_kicker)
rtc_writel(rtc, OMAP_RTC_KICK0_REG, 0);
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
return ret;
}
static int __exit omap_rtc_remove(struct platform_device *pdev)
{
struct omap_rtc *rtc = platform_get_drvdata(pdev);
device_init_wakeup(&pdev->dev, 0);
/* leave rtc running, but disable irqs */
rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
if (rtc->type->has_kicker)
rtc_writel(rtc, OMAP_RTC_KICK0_REG, 0);
/* Disable the clock/module */
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int omap_rtc_suspend(struct device *dev)
{
struct omap_rtc *rtc = dev_get_drvdata(dev);
rtc->interrupts_reg = rtc_read(rtc, OMAP_RTC_INTERRUPTS_REG);
/* FIXME the RTC alarm is not currently acting as a wakeup event
* source on some platforms, and in fact this enable() call is just
* saving a flag that's never used...
*/
if (device_may_wakeup(dev))
enable_irq_wake(rtc->irq_alarm);
else
rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
/* Disable the clock/module */
pm_runtime_put_sync(dev);
return 0;
}
static int omap_rtc_resume(struct device *dev)
{
struct omap_rtc *rtc = dev_get_drvdata(dev);
/* Enable the clock/module so that we can access the registers */
pm_runtime_get_sync(dev);
if (device_may_wakeup(dev))
disable_irq_wake(rtc->irq_alarm);
else
rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, rtc->interrupts_reg);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(omap_rtc_pm_ops, omap_rtc_suspend, omap_rtc_resume);
static void omap_rtc_shutdown(struct platform_device *pdev)
{
struct omap_rtc *rtc = platform_get_drvdata(pdev);
rtc_write(rtc, OMAP_RTC_INTERRUPTS_REG, 0);
}
static struct platform_driver omap_rtc_driver = {
.remove = __exit_p(omap_rtc_remove),
.shutdown = omap_rtc_shutdown,
.driver = {
.name = "omap_rtc",
.owner = THIS_MODULE,
.pm = &omap_rtc_pm_ops,
.of_match_table = omap_rtc_of_match,
},
.id_table = omap_rtc_id_table,
};
module_platform_driver_probe(omap_rtc_driver, omap_rtc_probe);
MODULE_ALIAS("platform:omap_rtc");
MODULE_AUTHOR("George G. Davis (and others)");
MODULE_LICENSE("GPL");
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