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rtc: add rtc-tx4939 driver
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Add support for RTC in TX4939 SoC.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Atsushi Nemoto authored and Linus Torvalds committed Jan 6, 2009
1 parent bbccf83 commit 0e14923
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7 changes: 7 additions & 0 deletions drivers/rtc/Kconfig
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Expand Up @@ -705,4 +705,11 @@ config RTC_DRV_STARFIRE
If you say Y here you will get support for the RTC found on
Starfire systems.

config RTC_DRV_TX4939
tristate "TX4939 SoC"
depends on SOC_TX4939
help
Driver for the internal RTC (Realtime Clock) module found on
Toshiba TX4939 SoC.

endif # RTC_CLASS
1 change: 1 addition & 0 deletions drivers/rtc/Makefile
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Expand Up @@ -68,6 +68,7 @@ obj-$(CONFIG_RTC_DRV_SH) += rtc-sh.o
obj-$(CONFIG_RTC_DRV_STK17TA8) += rtc-stk17ta8.o
obj-$(CONFIG_RTC_DRV_TEST) += rtc-test.o
obj-$(CONFIG_RTC_DRV_TWL4030) += rtc-twl4030.o
obj-$(CONFIG_RTC_DRV_TX4939) += rtc-tx4939.o
obj-$(CONFIG_RTC_DRV_V3020) += rtc-v3020.o
obj-$(CONFIG_RTC_DRV_VR41XX) += rtc-vr41xx.o
obj-$(CONFIG_RTC_DRV_WM8350) += rtc-wm8350.o
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317 changes: 317 additions & 0 deletions drivers/rtc/rtc-tx4939.c
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@@ -0,0 +1,317 @@
/*
* TX4939 internal RTC driver
* Based on RBTX49xx patch from CELF patch archive.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* (C) Copyright TOSHIBA CORPORATION 2005-2007
*/
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <asm/txx9/tx4939.h>

struct tx4939rtc_plat_data {
struct rtc_device *rtc;
struct tx4939_rtc_reg __iomem *rtcreg;
};

static struct tx4939rtc_plat_data *get_tx4939rtc_plat_data(struct device *dev)
{
return platform_get_drvdata(to_platform_device(dev));
}

static int tx4939_rtc_cmd(struct tx4939_rtc_reg __iomem *rtcreg, int cmd)
{
int i = 0;

__raw_writel(cmd, &rtcreg->ctl);
/* This might take 30us (next 32.768KHz clock) */
while (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_BUSY) {
/* timeout on approx. 100us (@ GBUS200MHz) */
if (i++ > 200 * 100)
return -EBUSY;
cpu_relax();
}
return 0;
}

static int tx4939_rtc_set_mmss(struct device *dev, unsigned long secs)
{
struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
int i, ret;
unsigned char buf[6];

buf[0] = 0;
buf[1] = 0;
buf[2] = secs;
buf[3] = secs >> 8;
buf[4] = secs >> 16;
buf[5] = secs >> 24;
spin_lock_irq(&pdata->rtc->irq_lock);
__raw_writel(0, &rtcreg->adr);
for (i = 0; i < 6; i++)
__raw_writel(buf[i], &rtcreg->dat);
ret = tx4939_rtc_cmd(rtcreg,
TX4939_RTCCTL_COMMAND_SETTIME |
(__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
spin_unlock_irq(&pdata->rtc->irq_lock);
return ret;
}

static int tx4939_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
int i, ret;
unsigned long sec;
unsigned char buf[6];

spin_lock_irq(&pdata->rtc->irq_lock);
ret = tx4939_rtc_cmd(rtcreg,
TX4939_RTCCTL_COMMAND_GETTIME |
(__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
if (ret) {
spin_unlock_irq(&pdata->rtc->irq_lock);
return ret;
}
__raw_writel(2, &rtcreg->adr);
for (i = 2; i < 6; i++)
buf[i] = __raw_readl(&rtcreg->dat);
spin_unlock_irq(&pdata->rtc->irq_lock);
sec = (buf[5] << 24) | (buf[4] << 16) | (buf[3] << 8) | buf[2];
rtc_time_to_tm(sec, tm);
return rtc_valid_tm(tm);
}

static int tx4939_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
int i, ret;
unsigned long sec;
unsigned char buf[6];

if (alrm->time.tm_sec < 0 ||
alrm->time.tm_min < 0 ||
alrm->time.tm_hour < 0 ||
alrm->time.tm_mday < 0 ||
alrm->time.tm_mon < 0 ||
alrm->time.tm_year < 0)
return -EINVAL;
rtc_tm_to_time(&alrm->time, &sec);
buf[0] = 0;
buf[1] = 0;
buf[2] = sec;
buf[3] = sec >> 8;
buf[4] = sec >> 16;
buf[5] = sec >> 24;
spin_lock_irq(&pdata->rtc->irq_lock);
__raw_writel(0, &rtcreg->adr);
for (i = 0; i < 6; i++)
__raw_writel(buf[i], &rtcreg->dat);
ret = tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_SETALARM |
(alrm->enabled ? TX4939_RTCCTL_ALME : 0));
spin_unlock_irq(&pdata->rtc->irq_lock);
return ret;
}

static int tx4939_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
int i, ret;
unsigned long sec;
unsigned char buf[6];
u32 ctl;

spin_lock_irq(&pdata->rtc->irq_lock);
ret = tx4939_rtc_cmd(rtcreg,
TX4939_RTCCTL_COMMAND_GETALARM |
(__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
if (ret) {
spin_unlock_irq(&pdata->rtc->irq_lock);
return ret;
}
__raw_writel(2, &rtcreg->adr);
for (i = 2; i < 6; i++)
buf[i] = __raw_readl(&rtcreg->dat);
ctl = __raw_readl(&rtcreg->ctl);
alrm->enabled = (ctl & TX4939_RTCCTL_ALME) ? 1 : 0;
alrm->pending = (ctl & TX4939_RTCCTL_ALMD) ? 1 : 0;
spin_unlock_irq(&pdata->rtc->irq_lock);
sec = (buf[5] << 24) | (buf[4] << 16) | (buf[3] << 8) | buf[2];
rtc_time_to_tm(sec, &alrm->time);
return rtc_valid_tm(&alrm->time);
}

static int tx4939_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);

spin_lock_irq(&pdata->rtc->irq_lock);
tx4939_rtc_cmd(pdata->rtcreg,
TX4939_RTCCTL_COMMAND_NOP |
(enabled ? TX4939_RTCCTL_ALME : 0));
spin_unlock_irq(&pdata->rtc->irq_lock);
return 0;
}

static irqreturn_t tx4939_rtc_interrupt(int irq, void *dev_id)
{
struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev_id);
struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
unsigned long events = RTC_IRQF;

spin_lock(&pdata->rtc->irq_lock);
if (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALMD) {
events |= RTC_AF;
tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_NOP);
}
spin_unlock(&pdata->rtc->irq_lock);
rtc_update_irq(pdata->rtc, 1, events);
return IRQ_HANDLED;
}

static const struct rtc_class_ops tx4939_rtc_ops = {
.read_time = tx4939_rtc_read_time,
.read_alarm = tx4939_rtc_read_alarm,
.set_alarm = tx4939_rtc_set_alarm,
.set_mmss = tx4939_rtc_set_mmss,
.alarm_irq_enable = tx4939_rtc_alarm_irq_enable,
};

static ssize_t tx4939_rtc_nvram_read(struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t pos, size_t size)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
ssize_t count;

spin_lock_irq(&pdata->rtc->irq_lock);
for (count = 0; size > 0 && pos < TX4939_RTC_REG_RAMSIZE;
count++, size--) {
__raw_writel(pos++, &rtcreg->adr);
*buf++ = __raw_readl(&rtcreg->dat);
}
spin_unlock_irq(&pdata->rtc->irq_lock);
return count;
}

static ssize_t tx4939_rtc_nvram_write(struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t pos, size_t size)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
ssize_t count;

spin_lock_irq(&pdata->rtc->irq_lock);
for (count = 0; size > 0 && pos < TX4939_RTC_REG_RAMSIZE;
count++, size--) {
__raw_writel(pos++, &rtcreg->adr);
__raw_writel(*buf++, &rtcreg->dat);
}
spin_unlock_irq(&pdata->rtc->irq_lock);
return count;
}

static struct bin_attribute tx4939_rtc_nvram_attr = {
.attr = {
.name = "nvram",
.mode = S_IRUGO | S_IWUSR,
},
.size = TX4939_RTC_REG_RAMSIZE,
.read = tx4939_rtc_nvram_read,
.write = tx4939_rtc_nvram_write,
};

static int __init tx4939_rtc_probe(struct platform_device *pdev)
{
struct rtc_device *rtc;
struct tx4939rtc_plat_data *pdata;
struct resource *res;
int irq, ret;

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENODEV;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return -ENODEV;
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return -ENOMEM;
platform_set_drvdata(pdev, pdata);

if (!devm_request_mem_region(&pdev->dev, res->start,
resource_size(res), pdev->name))
return -EBUSY;
pdata->rtcreg = devm_ioremap(&pdev->dev, res->start,
resource_size(res));
if (!pdata->rtcreg)
return -EBUSY;

tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
if (devm_request_irq(&pdev->dev, irq, tx4939_rtc_interrupt,
IRQF_DISABLED | IRQF_SHARED,
pdev->name, &pdev->dev) < 0) {
return -EBUSY;
}
rtc = rtc_device_register(pdev->name, &pdev->dev,
&tx4939_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
pdata->rtc = rtc;
ret = sysfs_create_bin_file(&pdev->dev.kobj, &tx4939_rtc_nvram_attr);
if (ret)
rtc_device_unregister(rtc);
return ret;
}

static int __exit tx4939_rtc_remove(struct platform_device *pdev)
{
struct tx4939rtc_plat_data *pdata = platform_get_drvdata(pdev);
struct rtc_device *rtc = pdata->rtc;

spin_lock_irq(&rtc->irq_lock);
tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
spin_unlock_irq(&rtc->irq_lock);
sysfs_remove_bin_file(&pdev->dev.kobj, &tx4939_rtc_nvram_attr);
rtc_device_unregister(rtc);
platform_set_drvdata(pdev, NULL);
return 0;
}

static struct platform_driver tx4939_rtc_driver = {
.remove = __exit_p(tx4939_rtc_remove),
.driver = {
.name = "tx4939rtc",
.owner = THIS_MODULE,
},
};

static int __init tx4939rtc_init(void)
{
return platform_driver_probe(&tx4939_rtc_driver, tx4939_rtc_probe);
}

static void __exit tx4939rtc_exit(void)
{
platform_driver_unregister(&tx4939_rtc_driver);
}

module_init(tx4939rtc_init);
module_exit(tx4939rtc_exit);

MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
MODULE_DESCRIPTION("TX4939 internal RTC driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:tx4939rtc");

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