linux/drivers/rtc/rtc-pl031.c
Linus Walleij 2f39721683 drivers/rtc/rtc-pl031.c: enable clock on all ST variants
The ST variants of the PL031 all require bit 26 in the control register
to be set before they work properly.  Discovered this when testing on
the Nomadik board where it would suprisingly just stand still.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
Cc: Alessandro Rubini <rubini@unipv.it>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-12 13:12:12 -07:00

437 lines
11 KiB
C

/*
* drivers/rtc/rtc-pl031.c
*
* Real Time Clock interface for ARM AMBA PrimeCell 031 RTC
*
* Author: Deepak Saxena <dsaxena@plexity.net>
*
* Copyright 2006 (c) MontaVista Software, Inc.
*
* Author: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
* Copyright 2010 (c) ST-Ericsson AB
*
* 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/module.h>
#include <linux/rtc.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/amba/bus.h>
#include <linux/io.h>
#include <linux/bcd.h>
#include <linux/delay.h>
#include <linux/slab.h>
/*
* Register definitions
*/
#define RTC_DR 0x00 /* Data read register */
#define RTC_MR 0x04 /* Match register */
#define RTC_LR 0x08 /* Data load register */
#define RTC_CR 0x0c /* Control register */
#define RTC_IMSC 0x10 /* Interrupt mask and set register */
#define RTC_RIS 0x14 /* Raw interrupt status register */
#define RTC_MIS 0x18 /* Masked interrupt status register */
#define RTC_ICR 0x1c /* Interrupt clear register */
/* ST variants have additional timer functionality */
#define RTC_TDR 0x20 /* Timer data read register */
#define RTC_TLR 0x24 /* Timer data load register */
#define RTC_TCR 0x28 /* Timer control register */
#define RTC_YDR 0x30 /* Year data read register */
#define RTC_YMR 0x34 /* Year match register */
#define RTC_YLR 0x38 /* Year data load register */
#define RTC_CR_CWEN (1 << 26) /* Clockwatch enable bit */
#define RTC_TCR_EN (1 << 1) /* Periodic timer enable bit */
/* Common bit definitions for Interrupt status and control registers */
#define RTC_BIT_AI (1 << 0) /* Alarm interrupt bit */
#define RTC_BIT_PI (1 << 1) /* Periodic interrupt bit. ST variants only. */
/* Common bit definations for ST v2 for reading/writing time */
#define RTC_SEC_SHIFT 0
#define RTC_SEC_MASK (0x3F << RTC_SEC_SHIFT) /* Second [0-59] */
#define RTC_MIN_SHIFT 6
#define RTC_MIN_MASK (0x3F << RTC_MIN_SHIFT) /* Minute [0-59] */
#define RTC_HOUR_SHIFT 12
#define RTC_HOUR_MASK (0x1F << RTC_HOUR_SHIFT) /* Hour [0-23] */
#define RTC_WDAY_SHIFT 17
#define RTC_WDAY_MASK (0x7 << RTC_WDAY_SHIFT) /* Day of Week [1-7] 1=Sunday */
#define RTC_MDAY_SHIFT 20
#define RTC_MDAY_MASK (0x1F << RTC_MDAY_SHIFT) /* Day of Month [1-31] */
#define RTC_MON_SHIFT 25
#define RTC_MON_MASK (0xF << RTC_MON_SHIFT) /* Month [1-12] 1=January */
#define RTC_TIMER_FREQ 32768
struct pl031_local {
struct rtc_device *rtc;
void __iomem *base;
u8 hw_designer;
u8 hw_revision:4;
};
static int pl031_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct pl031_local *ldata = dev_get_drvdata(dev);
unsigned long imsc;
/* Clear any pending alarm interrupts. */
writel(RTC_BIT_AI, ldata->base + RTC_ICR);
imsc = readl(ldata->base + RTC_IMSC);
if (enabled == 1)
writel(imsc | RTC_BIT_AI, ldata->base + RTC_IMSC);
else
writel(imsc & ~RTC_BIT_AI, ldata->base + RTC_IMSC);
return 0;
}
/*
* Convert Gregorian date to ST v2 RTC format.
*/
static int pl031_stv2_tm_to_time(struct device *dev,
struct rtc_time *tm, unsigned long *st_time,
unsigned long *bcd_year)
{
int year = tm->tm_year + 1900;
int wday = tm->tm_wday;
/* wday masking is not working in hardware so wday must be valid */
if (wday < -1 || wday > 6) {
dev_err(dev, "invalid wday value %d\n", tm->tm_wday);
return -EINVAL;
} else if (wday == -1) {
/* wday is not provided, calculate it here */
unsigned long time;
struct rtc_time calc_tm;
rtc_tm_to_time(tm, &time);
rtc_time_to_tm(time, &calc_tm);
wday = calc_tm.tm_wday;
}
*bcd_year = (bin2bcd(year % 100) | bin2bcd(year / 100) << 8);
*st_time = ((tm->tm_mon + 1) << RTC_MON_SHIFT)
| (tm->tm_mday << RTC_MDAY_SHIFT)
| ((wday + 1) << RTC_WDAY_SHIFT)
| (tm->tm_hour << RTC_HOUR_SHIFT)
| (tm->tm_min << RTC_MIN_SHIFT)
| (tm->tm_sec << RTC_SEC_SHIFT);
return 0;
}
/*
* Convert ST v2 RTC format to Gregorian date.
*/
static int pl031_stv2_time_to_tm(unsigned long st_time, unsigned long bcd_year,
struct rtc_time *tm)
{
tm->tm_year = bcd2bin(bcd_year) + (bcd2bin(bcd_year >> 8) * 100);
tm->tm_mon = ((st_time & RTC_MON_MASK) >> RTC_MON_SHIFT) - 1;
tm->tm_mday = ((st_time & RTC_MDAY_MASK) >> RTC_MDAY_SHIFT);
tm->tm_wday = ((st_time & RTC_WDAY_MASK) >> RTC_WDAY_SHIFT) - 1;
tm->tm_hour = ((st_time & RTC_HOUR_MASK) >> RTC_HOUR_SHIFT);
tm->tm_min = ((st_time & RTC_MIN_MASK) >> RTC_MIN_SHIFT);
tm->tm_sec = ((st_time & RTC_SEC_MASK) >> RTC_SEC_SHIFT);
tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
tm->tm_year -= 1900;
return 0;
}
static int pl031_stv2_read_time(struct device *dev, struct rtc_time *tm)
{
struct pl031_local *ldata = dev_get_drvdata(dev);
pl031_stv2_time_to_tm(readl(ldata->base + RTC_DR),
readl(ldata->base + RTC_YDR), tm);
return 0;
}
static int pl031_stv2_set_time(struct device *dev, struct rtc_time *tm)
{
unsigned long time;
unsigned long bcd_year;
struct pl031_local *ldata = dev_get_drvdata(dev);
int ret;
ret = pl031_stv2_tm_to_time(dev, tm, &time, &bcd_year);
if (ret == 0) {
writel(bcd_year, ldata->base + RTC_YLR);
writel(time, ldata->base + RTC_LR);
}
return ret;
}
static int pl031_stv2_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct pl031_local *ldata = dev_get_drvdata(dev);
int ret;
ret = pl031_stv2_time_to_tm(readl(ldata->base + RTC_MR),
readl(ldata->base + RTC_YMR), &alarm->time);
alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI;
alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI;
return ret;
}
static int pl031_stv2_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct pl031_local *ldata = dev_get_drvdata(dev);
unsigned long time;
unsigned long bcd_year;
int ret;
/* At the moment, we can only deal with non-wildcarded alarm times. */
ret = rtc_valid_tm(&alarm->time);
if (ret == 0) {
ret = pl031_stv2_tm_to_time(dev, &alarm->time,
&time, &bcd_year);
if (ret == 0) {
writel(bcd_year, ldata->base + RTC_YMR);
writel(time, ldata->base + RTC_MR);
pl031_alarm_irq_enable(dev, alarm->enabled);
}
}
return ret;
}
static irqreturn_t pl031_interrupt(int irq, void *dev_id)
{
struct pl031_local *ldata = dev_id;
unsigned long rtcmis;
unsigned long events = 0;
rtcmis = readl(ldata->base + RTC_MIS);
if (rtcmis) {
writel(rtcmis, ldata->base + RTC_ICR);
if (rtcmis & RTC_BIT_AI)
events |= (RTC_AF | RTC_IRQF);
/* Timer interrupt is only available in ST variants */
if ((rtcmis & RTC_BIT_PI) &&
(ldata->hw_designer == AMBA_VENDOR_ST))
events |= (RTC_PF | RTC_IRQF);
rtc_update_irq(ldata->rtc, 1, events);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static int pl031_read_time(struct device *dev, struct rtc_time *tm)
{
struct pl031_local *ldata = dev_get_drvdata(dev);
rtc_time_to_tm(readl(ldata->base + RTC_DR), tm);
return 0;
}
static int pl031_set_time(struct device *dev, struct rtc_time *tm)
{
unsigned long time;
struct pl031_local *ldata = dev_get_drvdata(dev);
int ret;
ret = rtc_tm_to_time(tm, &time);
if (ret == 0)
writel(time, ldata->base + RTC_LR);
return ret;
}
static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct pl031_local *ldata = dev_get_drvdata(dev);
rtc_time_to_tm(readl(ldata->base + RTC_MR), &alarm->time);
alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI;
alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI;
return 0;
}
static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct pl031_local *ldata = dev_get_drvdata(dev);
unsigned long time;
int ret;
/* At the moment, we can only deal with non-wildcarded alarm times. */
ret = rtc_valid_tm(&alarm->time);
if (ret == 0) {
ret = rtc_tm_to_time(&alarm->time, &time);
if (ret == 0) {
writel(time, ldata->base + RTC_MR);
pl031_alarm_irq_enable(dev, alarm->enabled);
}
}
return ret;
}
static int pl031_remove(struct amba_device *adev)
{
struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
amba_set_drvdata(adev, NULL);
free_irq(adev->irq[0], ldata->rtc);
rtc_device_unregister(ldata->rtc);
iounmap(ldata->base);
kfree(ldata);
amba_release_regions(adev);
return 0;
}
static int pl031_probe(struct amba_device *adev, const struct amba_id *id)
{
int ret;
struct pl031_local *ldata;
struct rtc_class_ops *ops = id->data;
ret = amba_request_regions(adev, NULL);
if (ret)
goto err_req;
ldata = kzalloc(sizeof(struct pl031_local), GFP_KERNEL);
if (!ldata) {
ret = -ENOMEM;
goto out;
}
ldata->base = ioremap(adev->res.start, resource_size(&adev->res));
if (!ldata->base) {
ret = -ENOMEM;
goto out_no_remap;
}
amba_set_drvdata(adev, ldata);
ldata->hw_designer = amba_manf(adev);
ldata->hw_revision = amba_rev(adev);
dev_dbg(&adev->dev, "designer ID = 0x%02x\n", ldata->hw_designer);
dev_dbg(&adev->dev, "revision = 0x%01x\n", ldata->hw_revision);
/* Enable the clockwatch on ST Variants */
if (ldata->hw_designer == AMBA_VENDOR_ST)
writel(readl(ldata->base + RTC_CR) | RTC_CR_CWEN,
ldata->base + RTC_CR);
ldata->rtc = rtc_device_register("pl031", &adev->dev, ops,
THIS_MODULE);
if (IS_ERR(ldata->rtc)) {
ret = PTR_ERR(ldata->rtc);
goto out_no_rtc;
}
if (request_irq(adev->irq[0], pl031_interrupt,
0, "rtc-pl031", ldata)) {
ret = -EIO;
goto out_no_irq;
}
return 0;
out_no_irq:
rtc_device_unregister(ldata->rtc);
out_no_rtc:
iounmap(ldata->base);
amba_set_drvdata(adev, NULL);
out_no_remap:
kfree(ldata);
out:
amba_release_regions(adev);
err_req:
return ret;
}
/* Operations for the original ARM version */
static struct rtc_class_ops arm_pl031_ops = {
.read_time = pl031_read_time,
.set_time = pl031_set_time,
.read_alarm = pl031_read_alarm,
.set_alarm = pl031_set_alarm,
.alarm_irq_enable = pl031_alarm_irq_enable,
};
/* The First ST derivative */
static struct rtc_class_ops stv1_pl031_ops = {
.read_time = pl031_read_time,
.set_time = pl031_set_time,
.read_alarm = pl031_read_alarm,
.set_alarm = pl031_set_alarm,
.alarm_irq_enable = pl031_alarm_irq_enable,
};
/* And the second ST derivative */
static struct rtc_class_ops stv2_pl031_ops = {
.read_time = pl031_stv2_read_time,
.set_time = pl031_stv2_set_time,
.read_alarm = pl031_stv2_read_alarm,
.set_alarm = pl031_stv2_set_alarm,
.alarm_irq_enable = pl031_alarm_irq_enable,
};
static struct amba_id pl031_ids[] = {
{
.id = 0x00041031,
.mask = 0x000fffff,
.data = &arm_pl031_ops,
},
/* ST Micro variants */
{
.id = 0x00180031,
.mask = 0x00ffffff,
.data = &stv1_pl031_ops,
},
{
.id = 0x00280031,
.mask = 0x00ffffff,
.data = &stv2_pl031_ops,
},
{0, 0},
};
MODULE_DEVICE_TABLE(amba, pl031_ids);
static struct amba_driver pl031_driver = {
.drv = {
.name = "rtc-pl031",
},
.id_table = pl031_ids,
.probe = pl031_probe,
.remove = pl031_remove,
};
module_amba_driver(pl031_driver);
MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net");
MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver");
MODULE_LICENSE("GPL");