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linux/drivers/rtc/rtc-davinci.c
Wolfram Sang f4e708ae8e rtc: davinci: Initialize drvdata before registering device 
Commit f44f7f96a2 ("RTC: Initialize kernel state from RTC") uncovered
an issue in a number of RTC drivers, where the drivers call
rtc_device_register before initializing the device or platform drvdata.

This frequently results in null pointer dereferences when the
rtc_device_register immediately makes use of the rtc device, calling
rtc_read_alarm.

The solution is to ensure the drvdata is initialized prior to registering
the rtc device.

CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: rtc-linux@googlegroups.com
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
[fixed up commit log -jstultz]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-05-06 17:41:06 -07:00

621 lines
16 KiB
C
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/*
* DaVinci Power Management and Real Time Clock Driver for TI platforms
*
* Copyright (C) 2009 Texas Instruments, Inc
*
* Author: Miguel Aguilar <miguel.aguilar@ridgerun.com>
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/slab.h>
/*
* The DaVinci RTC is a simple RTC with the following
* Sec: 0 - 59 : BCD count
* Min: 0 - 59 : BCD count
* Hour: 0 - 23 : BCD count
* Day: 0 - 0x7FFF(32767) : Binary count ( Over 89 years )
*/
/* PRTC interface registers */
#define DAVINCI_PRTCIF_PID 0x00
#define PRTCIF_CTLR 0x04
#define PRTCIF_LDATA 0x08
#define PRTCIF_UDATA 0x0C
#define PRTCIF_INTEN 0x10
#define PRTCIF_INTFLG 0x14
/* PRTCIF_CTLR bit fields */
#define PRTCIF_CTLR_BUSY BIT(31)
#define PRTCIF_CTLR_SIZE BIT(25)
#define PRTCIF_CTLR_DIR BIT(24)
#define PRTCIF_CTLR_BENU_MSB BIT(23)
#define PRTCIF_CTLR_BENU_3RD_BYTE BIT(22)
#define PRTCIF_CTLR_BENU_2ND_BYTE BIT(21)
#define PRTCIF_CTLR_BENU_LSB BIT(20)
#define PRTCIF_CTLR_BENU_MASK (0x00F00000)
#define PRTCIF_CTLR_BENL_MSB BIT(19)
#define PRTCIF_CTLR_BENL_3RD_BYTE BIT(18)
#define PRTCIF_CTLR_BENL_2ND_BYTE BIT(17)
#define PRTCIF_CTLR_BENL_LSB BIT(16)
#define PRTCIF_CTLR_BENL_MASK (0x000F0000)
/* PRTCIF_INTEN bit fields */
#define PRTCIF_INTEN_RTCSS BIT(1)
#define PRTCIF_INTEN_RTCIF BIT(0)
#define PRTCIF_INTEN_MASK (PRTCIF_INTEN_RTCSS \
| PRTCIF_INTEN_RTCIF)
/* PRTCIF_INTFLG bit fields */
#define PRTCIF_INTFLG_RTCSS BIT(1)
#define PRTCIF_INTFLG_RTCIF BIT(0)
#define PRTCIF_INTFLG_MASK (PRTCIF_INTFLG_RTCSS \
| PRTCIF_INTFLG_RTCIF)
/* PRTC subsystem registers */
#define PRTCSS_RTC_INTC_EXTENA1 (0x0C)
#define PRTCSS_RTC_CTRL (0x10)
#define PRTCSS_RTC_WDT (0x11)
#define PRTCSS_RTC_TMR0 (0x12)
#define PRTCSS_RTC_TMR1 (0x13)
#define PRTCSS_RTC_CCTRL (0x14)
#define PRTCSS_RTC_SEC (0x15)
#define PRTCSS_RTC_MIN (0x16)
#define PRTCSS_RTC_HOUR (0x17)
#define PRTCSS_RTC_DAY0 (0x18)
#define PRTCSS_RTC_DAY1 (0x19)
#define PRTCSS_RTC_AMIN (0x1A)
#define PRTCSS_RTC_AHOUR (0x1B)
#define PRTCSS_RTC_ADAY0 (0x1C)
#define PRTCSS_RTC_ADAY1 (0x1D)
#define PRTCSS_RTC_CLKC_CNT (0x20)
/* PRTCSS_RTC_INTC_EXTENA1 */
#define PRTCSS_RTC_INTC_EXTENA1_MASK (0x07)
/* PRTCSS_RTC_CTRL bit fields */
#define PRTCSS_RTC_CTRL_WDTBUS BIT(7)
#define PRTCSS_RTC_CTRL_WEN BIT(6)
#define PRTCSS_RTC_CTRL_WDRT BIT(5)
#define PRTCSS_RTC_CTRL_WDTFLG BIT(4)
#define PRTCSS_RTC_CTRL_TE BIT(3)
#define PRTCSS_RTC_CTRL_TIEN BIT(2)
#define PRTCSS_RTC_CTRL_TMRFLG BIT(1)
#define PRTCSS_RTC_CTRL_TMMD BIT(0)
/* PRTCSS_RTC_CCTRL bit fields */
#define PRTCSS_RTC_CCTRL_CALBUSY BIT(7)
#define PRTCSS_RTC_CCTRL_DAEN BIT(5)
#define PRTCSS_RTC_CCTRL_HAEN BIT(4)
#define PRTCSS_RTC_CCTRL_MAEN BIT(3)
#define PRTCSS_RTC_CCTRL_ALMFLG BIT(2)
#define PRTCSS_RTC_CCTRL_AIEN BIT(1)
#define PRTCSS_RTC_CCTRL_CAEN BIT(0)
static DEFINE_SPINLOCK(davinci_rtc_lock);
struct davinci_rtc {
struct rtc_device *rtc;
void __iomem *base;
resource_size_t pbase;
size_t base_size;
int irq;
};
static inline void rtcif_write(struct davinci_rtc *davinci_rtc,
u32 val, u32 addr)
{
writel(val, davinci_rtc->base + addr);
}
static inline u32 rtcif_read(struct davinci_rtc *davinci_rtc, u32 addr)
{
return readl(davinci_rtc->base + addr);
}
static inline void rtcif_wait(struct davinci_rtc *davinci_rtc)
{
while (rtcif_read(davinci_rtc, PRTCIF_CTLR) & PRTCIF_CTLR_BUSY)
cpu_relax();
}
static inline void rtcss_write(struct davinci_rtc *davinci_rtc,
unsigned long val, u8 addr)
{
rtcif_wait(davinci_rtc);
rtcif_write(davinci_rtc, PRTCIF_CTLR_BENL_LSB | addr, PRTCIF_CTLR);
rtcif_write(davinci_rtc, val, PRTCIF_LDATA);
rtcif_wait(davinci_rtc);
}
static inline u8 rtcss_read(struct davinci_rtc *davinci_rtc, u8 addr)
{
rtcif_wait(davinci_rtc);
rtcif_write(davinci_rtc, PRTCIF_CTLR_DIR | PRTCIF_CTLR_BENL_LSB | addr,
PRTCIF_CTLR);
rtcif_wait(davinci_rtc);
return rtcif_read(davinci_rtc, PRTCIF_LDATA);
}
static inline void davinci_rtcss_calendar_wait(struct davinci_rtc *davinci_rtc)
{
while (rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL) &
PRTCSS_RTC_CCTRL_CALBUSY)
cpu_relax();
}
static irqreturn_t davinci_rtc_interrupt(int irq, void *class_dev)
{
struct davinci_rtc *davinci_rtc = class_dev;
unsigned long events = 0;
u32 irq_flg;
u8 alm_irq, tmr_irq;
u8 rtc_ctrl, rtc_cctrl;
int ret = IRQ_NONE;
irq_flg = rtcif_read(davinci_rtc, PRTCIF_INTFLG) &
PRTCIF_INTFLG_RTCSS;
alm_irq = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL) &
PRTCSS_RTC_CCTRL_ALMFLG;
tmr_irq = rtcss_read(davinci_rtc, PRTCSS_RTC_CTRL) &
PRTCSS_RTC_CTRL_TMRFLG;
if (irq_flg) {
if (alm_irq) {
events |= RTC_IRQF | RTC_AF;
rtc_cctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL);
rtc_cctrl |= PRTCSS_RTC_CCTRL_ALMFLG;
rtcss_write(davinci_rtc, rtc_cctrl, PRTCSS_RTC_CCTRL);
} else if (tmr_irq) {
events |= RTC_IRQF | RTC_PF;
rtc_ctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CTRL);
rtc_ctrl |= PRTCSS_RTC_CTRL_TMRFLG;
rtcss_write(davinci_rtc, rtc_ctrl, PRTCSS_RTC_CTRL);
}
rtcif_write(davinci_rtc, PRTCIF_INTFLG_RTCSS,
PRTCIF_INTFLG);
rtc_update_irq(davinci_rtc->rtc, 1, events);
ret = IRQ_HANDLED;
}
return ret;
}
static int
davinci_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
u8 rtc_ctrl;
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&davinci_rtc_lock, flags);
rtc_ctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CTRL);
switch (cmd) {
case RTC_WIE_ON:
rtc_ctrl |= PRTCSS_RTC_CTRL_WEN | PRTCSS_RTC_CTRL_WDTFLG;
break;
case RTC_WIE_OFF:
rtc_ctrl &= ~PRTCSS_RTC_CTRL_WEN;
break;
default:
ret = -ENOIOCTLCMD;
}
rtcss_write(davinci_rtc, rtc_ctrl, PRTCSS_RTC_CTRL);
spin_unlock_irqrestore(&davinci_rtc_lock, flags);
return ret;
}
static int convertfromdays(u16 days, struct rtc_time *tm)
{
int tmp_days, year, mon;
for (year = 2000;; year++) {
tmp_days = rtc_year_days(1, 12, year);
if (days >= tmp_days)
days -= tmp_days;
else {
for (mon = 0;; mon++) {
tmp_days = rtc_month_days(mon, year);
if (days >= tmp_days) {
days -= tmp_days;
} else {
tm->tm_year = year - 1900;
tm->tm_mon = mon;
tm->tm_mday = days + 1;
break;
}
}
break;
}
}
return 0;
}
static int convert2days(u16 *days, struct rtc_time *tm)
{
int i;
*days = 0;
/* epoch == 1900 */
if (tm->tm_year < 100 || tm->tm_year > 199)
return -EINVAL;
for (i = 2000; i < 1900 + tm->tm_year; i++)
*days += rtc_year_days(1, 12, i);
*days += rtc_year_days(tm->tm_mday, tm->tm_mon, 1900 + tm->tm_year);
return 0;
}
static int davinci_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
u16 days = 0;
u8 day0, day1;
unsigned long flags;
spin_lock_irqsave(&davinci_rtc_lock, flags);
davinci_rtcss_calendar_wait(davinci_rtc);
tm->tm_sec = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_SEC));
davinci_rtcss_calendar_wait(davinci_rtc);
tm->tm_min = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_MIN));
davinci_rtcss_calendar_wait(davinci_rtc);
tm->tm_hour = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_HOUR));
davinci_rtcss_calendar_wait(davinci_rtc);
day0 = rtcss_read(davinci_rtc, PRTCSS_RTC_DAY0);
davinci_rtcss_calendar_wait(davinci_rtc);
day1 = rtcss_read(davinci_rtc, PRTCSS_RTC_DAY1);
spin_unlock_irqrestore(&davinci_rtc_lock, flags);
days |= day1;
days <<= 8;
days |= day0;
if (convertfromdays(days, tm) < 0)
return -EINVAL;
return 0;
}
static int davinci_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
u16 days;
u8 rtc_cctrl;
unsigned long flags;
if (convert2days(&days, tm) < 0)
return -EINVAL;
spin_lock_irqsave(&davinci_rtc_lock, flags);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, bin2bcd(tm->tm_sec), PRTCSS_RTC_SEC);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, bin2bcd(tm->tm_min), PRTCSS_RTC_MIN);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, bin2bcd(tm->tm_hour), PRTCSS_RTC_HOUR);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, days & 0xFF, PRTCSS_RTC_DAY0);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, (days & 0xFF00) >> 8, PRTCSS_RTC_DAY1);
rtc_cctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL);
rtc_cctrl |= PRTCSS_RTC_CCTRL_CAEN;
rtcss_write(davinci_rtc, rtc_cctrl, PRTCSS_RTC_CCTRL);
spin_unlock_irqrestore(&davinci_rtc_lock, flags);
return 0;
}
static int davinci_rtc_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
unsigned long flags;
u8 rtc_cctrl = rtcss_read(davinci_rtc, PRTCSS_RTC_CCTRL);
spin_lock_irqsave(&davinci_rtc_lock, flags);
if (enabled)
rtc_cctrl |= PRTCSS_RTC_CCTRL_DAEN |
PRTCSS_RTC_CCTRL_HAEN |
PRTCSS_RTC_CCTRL_MAEN |
PRTCSS_RTC_CCTRL_ALMFLG |
PRTCSS_RTC_CCTRL_AIEN;
else
rtc_cctrl &= ~PRTCSS_RTC_CCTRL_AIEN;
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, rtc_cctrl, PRTCSS_RTC_CCTRL);
spin_unlock_irqrestore(&davinci_rtc_lock, flags);
return 0;
}
static int davinci_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
u16 days = 0;
u8 day0, day1;
unsigned long flags;
spin_lock_irqsave(&davinci_rtc_lock, flags);
davinci_rtcss_calendar_wait(davinci_rtc);
alm->time.tm_min = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_AMIN));
davinci_rtcss_calendar_wait(davinci_rtc);
alm->time.tm_hour = bcd2bin(rtcss_read(davinci_rtc, PRTCSS_RTC_AHOUR));
davinci_rtcss_calendar_wait(davinci_rtc);
day0 = rtcss_read(davinci_rtc, PRTCSS_RTC_ADAY0);
davinci_rtcss_calendar_wait(davinci_rtc);
day1 = rtcss_read(davinci_rtc, PRTCSS_RTC_ADAY1);
spin_unlock_irqrestore(&davinci_rtc_lock, flags);
days |= day1;
days <<= 8;
days |= day0;
if (convertfromdays(days, &alm->time) < 0)
return -EINVAL;
alm->pending = !!(rtcss_read(davinci_rtc,
PRTCSS_RTC_CCTRL) &
PRTCSS_RTC_CCTRL_AIEN);
alm->enabled = alm->pending && device_may_wakeup(dev);
return 0;
}
static int davinci_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
struct davinci_rtc *davinci_rtc = dev_get_drvdata(dev);
unsigned long flags;
u16 days;
if (alm->time.tm_mday <= 0 && alm->time.tm_mon < 0
&& alm->time.tm_year < 0) {
struct rtc_time tm;
unsigned long now, then;
davinci_rtc_read_time(dev, &tm);
rtc_tm_to_time(&tm, &now);
alm->time.tm_mday = tm.tm_mday;
alm->time.tm_mon = tm.tm_mon;
alm->time.tm_year = tm.tm_year;
rtc_tm_to_time(&alm->time, &then);
if (then < now) {
rtc_time_to_tm(now + 24 * 60 * 60, &tm);
alm->time.tm_mday = tm.tm_mday;
alm->time.tm_mon = tm.tm_mon;
alm->time.tm_year = tm.tm_year;
}
}
if (convert2days(&days, &alm->time) < 0)
return -EINVAL;
spin_lock_irqsave(&davinci_rtc_lock, flags);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, bin2bcd(alm->time.tm_min), PRTCSS_RTC_AMIN);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, bin2bcd(alm->time.tm_hour), PRTCSS_RTC_AHOUR);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, days & 0xFF, PRTCSS_RTC_ADAY0);
davinci_rtcss_calendar_wait(davinci_rtc);
rtcss_write(davinci_rtc, (days & 0xFF00) >> 8, PRTCSS_RTC_ADAY1);
spin_unlock_irqrestore(&davinci_rtc_lock, flags);
return 0;
}
static struct rtc_class_ops davinci_rtc_ops = {
.ioctl = davinci_rtc_ioctl,
.read_time = davinci_rtc_read_time,
.set_time = davinci_rtc_set_time,
.alarm_irq_enable = davinci_rtc_alarm_irq_enable,
.read_alarm = davinci_rtc_read_alarm,
.set_alarm = davinci_rtc_set_alarm,
};
static int __init davinci_rtc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct davinci_rtc *davinci_rtc;
struct resource *res, *mem;
int ret = 0;
davinci_rtc = kzalloc(sizeof(struct davinci_rtc), GFP_KERNEL);
if (!davinci_rtc) {
dev_dbg(dev, "could not allocate memory for private data\n");
return -ENOMEM;
}
davinci_rtc->irq = platform_get_irq(pdev, 0);
if (davinci_rtc->irq < 0) {
dev_err(dev, "no RTC irq\n");
ret = davinci_rtc->irq;
goto fail1;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(dev, "no mem resource\n");
ret = -EINVAL;
goto fail1;
}
davinci_rtc->pbase = res->start;
davinci_rtc->base_size = resource_size(res);
mem = request_mem_region(davinci_rtc->pbase, davinci_rtc->base_size,
pdev->name);
if (!mem) {
dev_err(dev, "RTC registers at %08x are not free\n",
davinci_rtc->pbase);
ret = -EBUSY;
goto fail1;
}
davinci_rtc->base = ioremap(davinci_rtc->pbase, davinci_rtc->base_size);
if (!davinci_rtc->base) {
dev_err(dev, "unable to ioremap MEM resource\n");
ret = -ENOMEM;
goto fail2;
}
platform_set_drvdata(pdev, davinci_rtc);
davinci_rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
&davinci_rtc_ops, THIS_MODULE);
if (IS_ERR(davinci_rtc->rtc)) {
dev_err(dev, "unable to register RTC device, err %ld\n",
PTR_ERR(davinci_rtc->rtc));
goto fail3;
}
rtcif_write(davinci_rtc, PRTCIF_INTFLG_RTCSS, PRTCIF_INTFLG);
rtcif_write(davinci_rtc, 0, PRTCIF_INTEN);
rtcss_write(davinci_rtc, 0, PRTCSS_RTC_INTC_EXTENA1);
rtcss_write(davinci_rtc, 0, PRTCSS_RTC_CTRL);
rtcss_write(davinci_rtc, 0, PRTCSS_RTC_CCTRL);
ret = request_irq(davinci_rtc->irq, davinci_rtc_interrupt,
IRQF_DISABLED, "davinci_rtc", davinci_rtc);
if (ret < 0) {
dev_err(dev, "unable to register davinci RTC interrupt\n");
goto fail4;
}
/* Enable interrupts */
rtcif_write(davinci_rtc, PRTCIF_INTEN_RTCSS, PRTCIF_INTEN);
rtcss_write(davinci_rtc, PRTCSS_RTC_INTC_EXTENA1_MASK,
PRTCSS_RTC_INTC_EXTENA1);
rtcss_write(davinci_rtc, PRTCSS_RTC_CCTRL_CAEN, PRTCSS_RTC_CCTRL);
device_init_wakeup(&pdev->dev, 0);
return 0;
fail4:
rtc_device_unregister(davinci_rtc->rtc);
fail3:
platform_set_drvdata(pdev, NULL);
iounmap(davinci_rtc->base);
fail2:
release_mem_region(davinci_rtc->pbase, davinci_rtc->base_size);
fail1:
kfree(davinci_rtc);
return ret;
}
static int __devexit davinci_rtc_remove(struct platform_device *pdev)
{
struct davinci_rtc *davinci_rtc = platform_get_drvdata(pdev);
device_init_wakeup(&pdev->dev, 0);
rtcif_write(davinci_rtc, 0, PRTCIF_INTEN);
free_irq(davinci_rtc->irq, davinci_rtc);
rtc_device_unregister(davinci_rtc->rtc);
iounmap(davinci_rtc->base);
release_mem_region(davinci_rtc->pbase, davinci_rtc->base_size);
platform_set_drvdata(pdev, NULL);
kfree(davinci_rtc);
return 0;
}
static struct platform_driver davinci_rtc_driver = {
.probe = davinci_rtc_probe,
.remove = __devexit_p(davinci_rtc_remove),
.driver = {
.name = "rtc_davinci",
.owner = THIS_MODULE,
},
};
static int __init rtc_init(void)
{
return platform_driver_probe(&davinci_rtc_driver, davinci_rtc_probe);
}
module_init(rtc_init);
static void __exit rtc_exit(void)
{
platform_driver_unregister(&davinci_rtc_driver);
}
module_exit(rtc_exit);
MODULE_AUTHOR("Miguel Aguilar <miguel.aguilar@ridgerun.com>");
MODULE_DESCRIPTION("Texas Instruments DaVinci PRTC Driver");
MODULE_LICENSE("GPL");
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