Commit 8ae6e163 authored by Deepak Saxena's avatar Deepak Saxena Committed by Linus Torvalds

[PATCH] Add driver for ARM AMBA PL031 RTC

Add a driver for the ARM PL031 RTC found on some ARM SOCs.  The driver is
fairly trivial as the RTC only provides a read/write and alarm capability.

[akpm@osdl.org: compile fix]
Signed-off-by: default avatarDeepak <dsaxena@plexity.net>
Acked-by: default avatarAlessandro Zummo <a.zummo@towertech.it>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent dcd96379
......@@ -157,6 +157,16 @@ config RTC_DRV_VR41XX
To compile this driver as a module, choose M here: the
module will be called rtc-vr41xx.
config RTC_DRV_PL031
tristate "ARM AMBA PL031 RTC"
depends on RTC_CLASS && ARM_AMBA
help
If you say Y here you will get access to ARM AMBA
PrimeCell PL031 UART found on certain ARM SOCs.
To compile this driver as a module, choose M here: the
module will be called rtc-pl031.
config RTC_DRV_TEST
tristate "Test driver/device"
depends on RTC_CLASS
......
......@@ -20,3 +20,4 @@ obj-$(CONFIG_RTC_DRV_M48T86) += rtc-m48t86.o
obj-$(CONFIG_RTC_DRV_EP93XX) += rtc-ep93xx.o
obj-$(CONFIG_RTC_DRV_SA1100) += rtc-sa1100.o
obj-$(CONFIG_RTC_DRV_VR41XX) += rtc-vr41xx.o
obj-$(CONFIG_RTC_DRV_PL031) += rtc-pl031.o
/*
* 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.
*
* 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/platform_device.h>
#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/string.h>
#include <linux/pm.h>
#include <linux/amba/bus.h>
#include <asm/io.h>
#include <asm/bitops.h>
#include <asm/hardware.h>
#include <asm/irq.h>
#include <asm/rtc.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 */
struct pl031_local {
struct rtc_device *rtc;
void __iomem *base;
};
static irqreturn_t pl031_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
struct rtc_device *rtc = dev_id;
rtc_update_irq(&rtc->class_dev, 1, RTC_AF);
return IRQ_HANDLED;
}
static int pl031_open(struct device *dev)
{
/*
* We request IRQ in pl031_probe, so nothing to do here...
*/
return 0;
}
static void pl031_release(struct device *dev)
{
}
static int pl031_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
struct pl031_local *ldata = dev_get_drvdata(dev);
switch (cmd) {
case RTC_AIE_OFF:
__raw_writel(1, ldata->base + RTC_MIS);
return 0;
case RTC_AIE_ON:
__raw_writel(0, ldata->base + RTC_MIS);
return 0;
}
return -ENOIOCTLCMD;
}
static int pl031_read_time(struct device *dev, struct rtc_time *tm)
{
struct pl031_local *ldata = dev_get_drvdata(dev);
rtc_time_to_tm(__raw_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);
rtc_tm_to_time(tm, &time);
__raw_writel(time, ldata->base + RTC_LR);
return 0;
}
static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct pl031_local *ldata = dev_get_drvdata(dev);
rtc_time_to_tm(__raw_readl(ldata->base + RTC_MR), &alarm->time);
alarm->pending = __raw_readl(ldata->base + RTC_RIS);
alarm->enabled = __raw_readl(ldata->base + RTC_IMSC);
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;
rtc_tm_to_time(&alarm->time, &time);
__raw_writel(time, ldata->base + RTC_MR);
__raw_writel(!alarm->enabled, ldata->base + RTC_MIS);
return 0;
}
static struct rtc_class_ops pl031_ops = {
.open = pl031_open,
.release = pl031_release,
.ioctl = pl031_ioctl,
.read_time = pl031_read_time,
.set_time = pl031_set_time,
.read_alarm = pl031_read_alarm,
.set_alarm = pl031_set_alarm,
};
static int pl031_remove(struct amba_device *adev)
{
struct pl031_local *ldata = dev_get_drvdata(&adev->dev);
if (ldata) {
dev_set_drvdata(&adev->dev, NULL);
free_irq(adev->irq[0], ldata->rtc);
rtc_device_unregister(ldata->rtc);
iounmap(ldata->base);
kfree(ldata);
}
return 0;
}
static int pl031_probe(struct amba_device *adev, void *id)
{
int ret;
struct pl031_local *ldata;
ldata = kmalloc(sizeof(struct pl031_local), GFP_KERNEL);
if (!ldata) {
ret = -ENOMEM;
goto out;
}
dev_set_drvdata(&adev->dev, ldata);
ldata->base = ioremap(adev->res.start,
adev->res.end - adev->res.start + 1);
if (!ldata->base) {
ret = -ENOMEM;
goto out_no_remap;
}
if (request_irq(adev->irq[0], pl031_interrupt, SA_INTERRUPT,
"rtc-pl031", ldata->rtc)) {
ret = -EIO;
goto out_no_irq;
}
ldata->rtc = rtc_device_register("pl031", &adev->dev, &pl031_ops,
THIS_MODULE);
if (IS_ERR(ldata->rtc)) {
ret = PTR_ERR(ldata->rtc);
goto out_no_rtc;
}
return 0;
out_no_rtc:
free_irq(adev->irq[0], ldata->rtc);
out_no_irq:
iounmap(ldata->base);
out_no_remap:
dev_set_drvdata(&adev->dev, NULL);
kfree(ldata);
out:
return ret;
}
static struct amba_id pl031_ids[] __initdata = {
{
.id = 0x00041031,
.mask = 0x000fffff, },
{0, 0},
};
static struct amba_driver pl031_driver = {
.drv = {
.name = "rtc-pl031",
},
.id_table = pl031_ids,
.probe = pl031_probe,
.remove = pl031_remove,
};
static int __init pl031_init(void)
{
return amba_driver_register(&pl031_driver);
}
static void __exit pl031_exit(void)
{
amba_driver_unregister(&pl031_driver);
}
module_init(pl031_init);
module_exit(pl031_exit);
MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net");
MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver");
MODULE_LICENSE("GPL");
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