- 根目录:
- drivers
- rtc
- rtc-pl031.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_EN (1 << 0) /* counter enable bit */
#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_vendor_data - per-vendor variations
* @ops: the vendor-specific operations used on this silicon version
* @clockwatch: if this is an ST Microelectronics silicon version with a
* clockwatch function
* @st_weekday: if this is an ST Microelectronics silicon version that need
* the weekday fix
* @irqflags: special IRQ flags per variant
*/
struct pl031_vendor_data {
struct rtc_class_ops ops;
bool clockwatch;
bool st_weekday;
unsigned long irqflags;
};
struct pl031_local {
struct pl031_vendor_data *vendor;
struct rtc_device *rtc;
void __iomem *base;
};
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 & RTC_BIT_AI) {
writel(RTC_BIT_AI, ldata->base + RTC_ICR);
events |= (RTC_AF | 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);
free_irq(adev->irq[0], ldata);
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 pl031_vendor_data *vendor = id->data;
struct rtc_class_ops *ops = &vendor->ops;
unsigned long time, 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->vendor = vendor;
ldata->base = ioremap(adev->res.start, resource_size(&adev->res));
if (!ldata->base) {
ret = -ENOMEM;
goto out_no_remap;
}
amba_set_drvdata(adev, ldata);
dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev));
dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev));
data = readl(ldata->base + RTC_CR);
/* Enable the clockwatch on ST Variants */
if (vendor->clockwatch)
data |= RTC_CR_CWEN;
else
data |= RTC_CR_EN;
writel(data, ldata->base + RTC_CR);
/*
* On ST PL031 variants, the RTC reset value does not provide correct
* weekday for 2000-01-01. Correct the erroneous sunday to saturday.
*/
if (vendor->st_weekday) {
if (readl(ldata->base + RTC_YDR) == 0x2000) {
time = readl(ldata->base + RTC_DR);
if ((time &
(RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK))
== 0x02120000) {
time = time | (0x7 << RTC_WDAY_SHIFT);
writel(0x2000, ldata->base + RTC_YLR);
writel(time, ldata->base + RTC_LR);
}
}
}
device_init_wakeup(&adev->dev, 1);
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,
vendor->irqflags, "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);
out_no_remap:
kfree(ldata);
out:
amba_release_regions(adev);
err_req:
return ret;
}
/* Operations for the original ARM version */
static struct pl031_vendor_data 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,
},
.irqflags = IRQF_NO_SUSPEND,
};
/* The First ST derivative */
static struct pl031_vendor_data 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,
},
.clockwatch = true,
.st_weekday = true,
.irqflags = IRQF_NO_SUSPEND,
};
/* And the second ST derivative */
static struct pl031_vendor_data 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,
},
.clockwatch = true,
.st_weekday = true,
/*
* This variant shares the IRQ with another block and must not
* suspend that IRQ line.
*/
.irqflags = IRQF_SHARED | IRQF_NO_SUSPEND,
};
static struct amba_id pl031_ids[] = {
{
.id = 0x00041031,
.mask = 0x000fffff,
.data = &arm_pl031,
},
/* ST Micro variants */
{
.id = 0x00180031,
.mask = 0x00ffffff,
.data = &stv1_pl031,
},
{
.id = 0x00280031,
.mask = 0x00ffffff,
.data = &stv2_pl031,
},
{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");