linux/drivers/rtc/rtc-omap.c
Vaibhav Hiremath fc9bd9022e rtc: omap: add runtime pm support
OMAP1 RTC driver is used in multiple devices like, OMAPL138 and AM33XX.
Driver currently doesn't handle any clocks, which may be right for OMAP1
architecture but in case of AM33XX, the clock/module needs to be enabled
in order to access the registers.

So convert this driver to runtime pm, which internally handles rest.

[afzal@ti.com: handle error path]
Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Afzal Mohammed <afzal@ti.com>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Sekhar Nori <nsekhar@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Daniel Mack <zonque@gmail.com>
Cc: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17 17:15:20 -08:00

567 lines
15 KiB
C

/*
* 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 <asm/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.
*/
#define DRIVER_NAME "omap_rtc"
#define OMAP_RTC_BASE 0xfffb4800
/* 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
/* OMAP_RTC_CTRL_REG bit fields: */
#define OMAP_RTC_CTRL_SPLIT (1<<7)
#define OMAP_RTC_CTRL_DISABLE (1<<6)
#define OMAP_RTC_CTRL_SET_32_COUNTER (1<<5)
#define OMAP_RTC_CTRL_TEST (1<<4)
#define OMAP_RTC_CTRL_MODE_12_24 (1<<3)
#define OMAP_RTC_CTRL_AUTO_COMP (1<<2)
#define OMAP_RTC_CTRL_ROUND_30S (1<<1)
#define OMAP_RTC_CTRL_STOP (1<<0)
/* OMAP_RTC_STATUS_REG bit fields: */
#define OMAP_RTC_STATUS_POWER_UP (1<<7)
#define OMAP_RTC_STATUS_ALARM (1<<6)
#define OMAP_RTC_STATUS_1D_EVENT (1<<5)
#define OMAP_RTC_STATUS_1H_EVENT (1<<4)
#define OMAP_RTC_STATUS_1M_EVENT (1<<3)
#define OMAP_RTC_STATUS_1S_EVENT (1<<2)
#define OMAP_RTC_STATUS_RUN (1<<1)
#define OMAP_RTC_STATUS_BUSY (1<<0)
/* OMAP_RTC_INTERRUPTS_REG bit fields: */
#define OMAP_RTC_INTERRUPTS_IT_ALARM (1<<3)
#define OMAP_RTC_INTERRUPTS_IT_TIMER (1<<2)
/* OMAP_RTC_KICKER values */
#define KICK0_VALUE 0x83e70b13
#define KICK1_VALUE 0x95a4f1e0
#define OMAP_RTC_HAS_KICKER 0x1
static void __iomem *rtc_base;
#define rtc_read(addr) readb(rtc_base + (addr))
#define rtc_write(val, addr) writeb(val, rtc_base + (addr))
#define rtc_writel(val, addr) writel(val, rtc_base + (addr))
/* 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(void)
{
int count = 0;
u8 status;
/* BUSY may stay active for 1/32768 second (~30 usec) */
for (count = 0; count < 50; count++) {
status = rtc_read(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 *rtc)
{
unsigned long events = 0;
u8 irq_data;
irq_data = rtc_read(OMAP_RTC_STATUS_REG);
/* alarm irq? */
if (irq_data & OMAP_RTC_STATUS_ALARM) {
rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
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, 1, events);
return IRQ_HANDLED;
}
static int omap_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
u8 reg;
local_irq_disable();
rtc_wait_not_busy();
reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
if (enabled)
reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
else
reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
rtc_wait_not_busy();
rtc_write(reg, OMAP_RTC_INTERRUPTS_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 int omap_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
/* we don't report wday/yday/isdst ... */
local_irq_disable();
rtc_wait_not_busy();
tm->tm_sec = rtc_read(OMAP_RTC_SECONDS_REG);
tm->tm_min = rtc_read(OMAP_RTC_MINUTES_REG);
tm->tm_hour = rtc_read(OMAP_RTC_HOURS_REG);
tm->tm_mday = rtc_read(OMAP_RTC_DAYS_REG);
tm->tm_mon = rtc_read(OMAP_RTC_MONTHS_REG);
tm->tm_year = rtc_read(OMAP_RTC_YEARS_REG);
local_irq_enable();
bcd2tm(tm);
return 0;
}
static int omap_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
if (tm2bcd(tm) < 0)
return -EINVAL;
local_irq_disable();
rtc_wait_not_busy();
rtc_write(tm->tm_year, OMAP_RTC_YEARS_REG);
rtc_write(tm->tm_mon, OMAP_RTC_MONTHS_REG);
rtc_write(tm->tm_mday, OMAP_RTC_DAYS_REG);
rtc_write(tm->tm_hour, OMAP_RTC_HOURS_REG);
rtc_write(tm->tm_min, OMAP_RTC_MINUTES_REG);
rtc_write(tm->tm_sec, OMAP_RTC_SECONDS_REG);
local_irq_enable();
return 0;
}
static int omap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
local_irq_disable();
rtc_wait_not_busy();
alm->time.tm_sec = rtc_read(OMAP_RTC_ALARM_SECONDS_REG);
alm->time.tm_min = rtc_read(OMAP_RTC_ALARM_MINUTES_REG);
alm->time.tm_hour = rtc_read(OMAP_RTC_ALARM_HOURS_REG);
alm->time.tm_mday = rtc_read(OMAP_RTC_ALARM_DAYS_REG);
alm->time.tm_mon = rtc_read(OMAP_RTC_ALARM_MONTHS_REG);
alm->time.tm_year = rtc_read(OMAP_RTC_ALARM_YEARS_REG);
local_irq_enable();
bcd2tm(&alm->time);
alm->enabled = !!(rtc_read(OMAP_RTC_INTERRUPTS_REG)
& OMAP_RTC_INTERRUPTS_IT_ALARM);
return 0;
}
static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
u8 reg;
if (tm2bcd(&alm->time) < 0)
return -EINVAL;
local_irq_disable();
rtc_wait_not_busy();
rtc_write(alm->time.tm_year, OMAP_RTC_ALARM_YEARS_REG);
rtc_write(alm->time.tm_mon, OMAP_RTC_ALARM_MONTHS_REG);
rtc_write(alm->time.tm_mday, OMAP_RTC_ALARM_DAYS_REG);
rtc_write(alm->time.tm_hour, OMAP_RTC_ALARM_HOURS_REG);
rtc_write(alm->time.tm_min, OMAP_RTC_ALARM_MINUTES_REG);
rtc_write(alm->time.tm_sec, OMAP_RTC_ALARM_SECONDS_REG);
reg = rtc_read(OMAP_RTC_INTERRUPTS_REG);
if (alm->enabled)
reg |= OMAP_RTC_INTERRUPTS_IT_ALARM;
else
reg &= ~OMAP_RTC_INTERRUPTS_IT_ALARM;
rtc_write(reg, OMAP_RTC_INTERRUPTS_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 int omap_rtc_alarm;
static int omap_rtc_timer;
#define OMAP_RTC_DATA_DA830_IDX 1
static struct platform_device_id omap_rtc_devtype[] = {
{
.name = DRIVER_NAME,
}, {
.name = "da830-rtc",
.driver_data = OMAP_RTC_HAS_KICKER,
},
{},
};
MODULE_DEVICE_TABLE(platform, omap_rtc_devtype);
static const struct of_device_id omap_rtc_of_match[] = {
{ .compatible = "ti,da830-rtc",
.data = &omap_rtc_devtype[OMAP_RTC_DATA_DA830_IDX],
},
{},
};
MODULE_DEVICE_TABLE(of, omap_rtc_of_match);
static int __init omap_rtc_probe(struct platform_device *pdev)
{
struct resource *res, *mem;
struct rtc_device *rtc;
u8 reg, new_ctrl;
const struct platform_device_id *id_entry;
const struct of_device_id *of_id;
of_id = of_match_device(omap_rtc_of_match, &pdev->dev);
if (of_id)
pdev->id_entry = of_id->data;
omap_rtc_timer = platform_get_irq(pdev, 0);
if (omap_rtc_timer <= 0) {
pr_debug("%s: no update irq?\n", pdev->name);
return -ENOENT;
}
omap_rtc_alarm = platform_get_irq(pdev, 1);
if (omap_rtc_alarm <= 0) {
pr_debug("%s: no alarm irq?\n", pdev->name);
return -ENOENT;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
pr_debug("%s: RTC resource data missing\n", pdev->name);
return -ENOENT;
}
mem = request_mem_region(res->start, resource_size(res), pdev->name);
if (!mem) {
pr_debug("%s: RTC registers at %08x are not free\n",
pdev->name, res->start);
return -EBUSY;
}
rtc_base = ioremap(res->start, resource_size(res));
if (!rtc_base) {
pr_debug("%s: RTC registers can't be mapped\n", pdev->name);
goto fail;
}
/* Enable the clock/module so that we can access the registers */
pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);
id_entry = platform_get_device_id(pdev);
if (id_entry && (id_entry->driver_data & OMAP_RTC_HAS_KICKER)) {
rtc_writel(KICK0_VALUE, OMAP_RTC_KICK0_REG);
rtc_writel(KICK1_VALUE, OMAP_RTC_KICK1_REG);
}
rtc = rtc_device_register(pdev->name, &pdev->dev,
&omap_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc)) {
pr_debug("%s: can't register RTC device, err %ld\n",
pdev->name, PTR_ERR(rtc));
goto fail0;
}
platform_set_drvdata(pdev, rtc);
dev_set_drvdata(&rtc->dev, mem);
/* clear pending irqs, and set 1/second periodic,
* which we'll use instead of update irqs
*/
rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
/* clear old status */
reg = rtc_read(OMAP_RTC_STATUS_REG);
if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
pr_info("%s: RTC power up reset detected\n",
pdev->name);
rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG);
}
if (reg & (u8) OMAP_RTC_STATUS_ALARM)
rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
/* handle periodic and alarm irqs */
if (request_irq(omap_rtc_timer, rtc_irq, 0,
dev_name(&rtc->dev), rtc)) {
pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
pdev->name, omap_rtc_timer);
goto fail1;
}
if ((omap_rtc_timer != omap_rtc_alarm) &&
(request_irq(omap_rtc_alarm, rtc_irq, 0,
dev_name(&rtc->dev), rtc))) {
pr_debug("%s: RTC alarm interrupt IRQ%d already claimed\n",
pdev->name, omap_rtc_alarm);
goto fail2;
}
/* On boards with split power, RTC_ON_NOFF won't reset the RTC */
reg = rtc_read(OMAP_RTC_CTRL_REG);
if (reg & (u8) OMAP_RTC_CTRL_STOP)
pr_info("%s: already running\n", pdev->name);
/* 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)
pr_info("%s: split power mode\n", pdev->name);
if (reg != new_ctrl)
rtc_write(new_ctrl, OMAP_RTC_CTRL_REG);
return 0;
fail2:
free_irq(omap_rtc_timer, rtc);
fail1:
rtc_device_unregister(rtc);
fail0:
if (id_entry && (id_entry->driver_data & OMAP_RTC_HAS_KICKER))
rtc_writel(0, OMAP_RTC_KICK0_REG);
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
iounmap(rtc_base);
fail:
release_mem_region(mem->start, resource_size(mem));
return -EIO;
}
static int __exit omap_rtc_remove(struct platform_device *pdev)
{
struct rtc_device *rtc = platform_get_drvdata(pdev);
struct resource *mem = dev_get_drvdata(&rtc->dev);
const struct platform_device_id *id_entry =
platform_get_device_id(pdev);
device_init_wakeup(&pdev->dev, 0);
/* leave rtc running, but disable irqs */
rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
free_irq(omap_rtc_timer, rtc);
if (omap_rtc_timer != omap_rtc_alarm)
free_irq(omap_rtc_alarm, rtc);
rtc_device_unregister(rtc);
if (id_entry && (id_entry->driver_data & OMAP_RTC_HAS_KICKER))
rtc_writel(0, OMAP_RTC_KICK0_REG);
/* Disable the clock/module */
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
iounmap(rtc_base);
release_mem_region(mem->start, resource_size(mem));
return 0;
}
#ifdef CONFIG_PM
static u8 irqstat;
static int omap_rtc_suspend(struct platform_device *pdev, pm_message_t state)
{
irqstat = rtc_read(OMAP_RTC_INTERRUPTS_REG);
/* FIXME the RTC alarm is not currently acting as a wakeup event
* source, and in fact this enable() call is just saving a flag
* that's never used...
*/
if (device_may_wakeup(&pdev->dev))
enable_irq_wake(omap_rtc_alarm);
else
rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
/* Disable the clock/module */
pm_runtime_put_sync(&pdev->dev);
return 0;
}
static int omap_rtc_resume(struct platform_device *pdev)
{
/* Enable the clock/module so that we can access the registers */
pm_runtime_get_sync(&pdev->dev);
if (device_may_wakeup(&pdev->dev))
disable_irq_wake(omap_rtc_alarm);
else
rtc_write(irqstat, OMAP_RTC_INTERRUPTS_REG);
return 0;
}
#else
#define omap_rtc_suspend NULL
#define omap_rtc_resume NULL
#endif
static void omap_rtc_shutdown(struct platform_device *pdev)
{
rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
}
MODULE_ALIAS("platform:omap_rtc");
static struct platform_driver omap_rtc_driver = {
.remove = __exit_p(omap_rtc_remove),
.suspend = omap_rtc_suspend,
.resume = omap_rtc_resume,
.shutdown = omap_rtc_shutdown,
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(omap_rtc_of_match),
},
.id_table = omap_rtc_devtype,
};
static int __init rtc_init(void)
{
return platform_driver_probe(&omap_rtc_driver, omap_rtc_probe);
}
module_init(rtc_init);
static void __exit rtc_exit(void)
{
platform_driver_unregister(&omap_rtc_driver);
}
module_exit(rtc_exit);
MODULE_AUTHOR("George G. Davis (and others)");
MODULE_LICENSE("GPL");