mirror of
https://github.com/torvalds/linux.git
synced 2024-12-16 08:02:17 +00:00
93015236d9
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: Wolfram Sang <w.sang@pengutronix.de>
CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: rtc-linux@googlegroups.com
Signed-off-by: John Stultz <john.stultz@linaro.org>
272 lines
7.4 KiB
C
272 lines
7.4 KiB
C
/*
|
|
* Oki MSM6242 RTC Driver
|
|
*
|
|
* Copyright 2009 Geert Uytterhoeven
|
|
*
|
|
* Based on the A2000 TOD code in arch/m68k/amiga/config.c
|
|
* Copyright (C) 1993 Hamish Macdonald
|
|
*/
|
|
|
|
#include <linux/delay.h>
|
|
#include <linux/io.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/slab.h>
|
|
|
|
|
|
enum {
|
|
MSM6242_SECOND1 = 0x0, /* 1-second digit register */
|
|
MSM6242_SECOND10 = 0x1, /* 10-second digit register */
|
|
MSM6242_MINUTE1 = 0x2, /* 1-minute digit register */
|
|
MSM6242_MINUTE10 = 0x3, /* 10-minute digit register */
|
|
MSM6242_HOUR1 = 0x4, /* 1-hour digit register */
|
|
MSM6242_HOUR10 = 0x5, /* PM/AM, 10-hour digit register */
|
|
MSM6242_DAY1 = 0x6, /* 1-day digit register */
|
|
MSM6242_DAY10 = 0x7, /* 10-day digit register */
|
|
MSM6242_MONTH1 = 0x8, /* 1-month digit register */
|
|
MSM6242_MONTH10 = 0x9, /* 10-month digit register */
|
|
MSM6242_YEAR1 = 0xa, /* 1-year digit register */
|
|
MSM6242_YEAR10 = 0xb, /* 10-year digit register */
|
|
MSM6242_WEEK = 0xc, /* Week register */
|
|
MSM6242_CD = 0xd, /* Control Register D */
|
|
MSM6242_CE = 0xe, /* Control Register E */
|
|
MSM6242_CF = 0xf, /* Control Register F */
|
|
};
|
|
|
|
#define MSM6242_HOUR10_AM (0 << 2)
|
|
#define MSM6242_HOUR10_PM (1 << 2)
|
|
#define MSM6242_HOUR10_HR_MASK (3 << 0)
|
|
|
|
#define MSM6242_WEEK_SUNDAY 0
|
|
#define MSM6242_WEEK_MONDAY 1
|
|
#define MSM6242_WEEK_TUESDAY 2
|
|
#define MSM6242_WEEK_WEDNESDAY 3
|
|
#define MSM6242_WEEK_THURSDAY 4
|
|
#define MSM6242_WEEK_FRIDAY 5
|
|
#define MSM6242_WEEK_SATURDAY 6
|
|
|
|
#define MSM6242_CD_30_S_ADJ (1 << 3) /* 30-second adjustment */
|
|
#define MSM6242_CD_IRQ_FLAG (1 << 2)
|
|
#define MSM6242_CD_BUSY (1 << 1)
|
|
#define MSM6242_CD_HOLD (1 << 0)
|
|
|
|
#define MSM6242_CE_T_MASK (3 << 2)
|
|
#define MSM6242_CE_T_64HZ (0 << 2) /* period 1/64 second */
|
|
#define MSM6242_CE_T_1HZ (1 << 2) /* period 1 second */
|
|
#define MSM6242_CE_T_1MINUTE (2 << 2) /* period 1 minute */
|
|
#define MSM6242_CE_T_1HOUR (3 << 2) /* period 1 hour */
|
|
|
|
#define MSM6242_CE_ITRPT_STND (1 << 1)
|
|
#define MSM6242_CE_MASK (1 << 0) /* STD.P output control */
|
|
|
|
#define MSM6242_CF_TEST (1 << 3)
|
|
#define MSM6242_CF_12H (0 << 2)
|
|
#define MSM6242_CF_24H (1 << 2)
|
|
#define MSM6242_CF_STOP (1 << 1)
|
|
#define MSM6242_CF_REST (1 << 0) /* reset */
|
|
|
|
|
|
struct msm6242_priv {
|
|
u32 __iomem *regs;
|
|
struct rtc_device *rtc;
|
|
};
|
|
|
|
static inline unsigned int msm6242_read(struct msm6242_priv *priv,
|
|
unsigned int reg)
|
|
{
|
|
return __raw_readl(&priv->regs[reg]) & 0xf;
|
|
}
|
|
|
|
static inline void msm6242_write(struct msm6242_priv *priv, unsigned int val,
|
|
unsigned int reg)
|
|
{
|
|
__raw_writel(val, &priv->regs[reg]);
|
|
}
|
|
|
|
static inline void msm6242_set(struct msm6242_priv *priv, unsigned int val,
|
|
unsigned int reg)
|
|
{
|
|
msm6242_write(priv, msm6242_read(priv, reg) | val, reg);
|
|
}
|
|
|
|
static inline void msm6242_clear(struct msm6242_priv *priv, unsigned int val,
|
|
unsigned int reg)
|
|
{
|
|
msm6242_write(priv, msm6242_read(priv, reg) & ~val, reg);
|
|
}
|
|
|
|
static void msm6242_lock(struct msm6242_priv *priv)
|
|
{
|
|
int cnt = 5;
|
|
|
|
msm6242_set(priv, MSM6242_CD_HOLD, MSM6242_CD);
|
|
|
|
while ((msm6242_read(priv, MSM6242_CD) & MSM6242_CD_BUSY) && cnt) {
|
|
msm6242_clear(priv, MSM6242_CD_HOLD, MSM6242_CD);
|
|
udelay(70);
|
|
msm6242_set(priv, MSM6242_CD_HOLD, MSM6242_CD);
|
|
cnt--;
|
|
}
|
|
|
|
if (!cnt)
|
|
pr_warning("msm6242: timed out waiting for RTC (0x%x)\n",
|
|
msm6242_read(priv, MSM6242_CD));
|
|
}
|
|
|
|
static void msm6242_unlock(struct msm6242_priv *priv)
|
|
{
|
|
msm6242_clear(priv, MSM6242_CD_HOLD, MSM6242_CD);
|
|
}
|
|
|
|
static int msm6242_read_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct msm6242_priv *priv = dev_get_drvdata(dev);
|
|
|
|
msm6242_lock(priv);
|
|
|
|
tm->tm_sec = msm6242_read(priv, MSM6242_SECOND10) * 10 +
|
|
msm6242_read(priv, MSM6242_SECOND1);
|
|
tm->tm_min = msm6242_read(priv, MSM6242_MINUTE10) * 10 +
|
|
msm6242_read(priv, MSM6242_MINUTE1);
|
|
tm->tm_hour = (msm6242_read(priv, MSM6242_HOUR10 & 3)) * 10 +
|
|
msm6242_read(priv, MSM6242_HOUR1);
|
|
tm->tm_mday = msm6242_read(priv, MSM6242_DAY10) * 10 +
|
|
msm6242_read(priv, MSM6242_DAY1);
|
|
tm->tm_wday = msm6242_read(priv, MSM6242_WEEK);
|
|
tm->tm_mon = msm6242_read(priv, MSM6242_MONTH10) * 10 +
|
|
msm6242_read(priv, MSM6242_MONTH1) - 1;
|
|
tm->tm_year = msm6242_read(priv, MSM6242_YEAR10) * 10 +
|
|
msm6242_read(priv, MSM6242_YEAR1);
|
|
if (tm->tm_year <= 69)
|
|
tm->tm_year += 100;
|
|
|
|
if (!(msm6242_read(priv, MSM6242_CF) & MSM6242_CF_24H)) {
|
|
unsigned int pm = msm6242_read(priv, MSM6242_HOUR10) &
|
|
MSM6242_HOUR10_PM;
|
|
if (!pm && tm->tm_hour == 12)
|
|
tm->tm_hour = 0;
|
|
else if (pm && tm->tm_hour != 12)
|
|
tm->tm_hour += 12;
|
|
}
|
|
|
|
msm6242_unlock(priv);
|
|
|
|
return rtc_valid_tm(tm);
|
|
}
|
|
|
|
static int msm6242_set_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct msm6242_priv *priv = dev_get_drvdata(dev);
|
|
|
|
msm6242_lock(priv);
|
|
|
|
msm6242_write(priv, tm->tm_sec / 10, MSM6242_SECOND10);
|
|
msm6242_write(priv, tm->tm_sec % 10, MSM6242_SECOND1);
|
|
msm6242_write(priv, tm->tm_min / 10, MSM6242_MINUTE10);
|
|
msm6242_write(priv, tm->tm_min % 10, MSM6242_MINUTE1);
|
|
if (msm6242_read(priv, MSM6242_CF) & MSM6242_CF_24H)
|
|
msm6242_write(priv, tm->tm_hour / 10, MSM6242_HOUR10);
|
|
else if (tm->tm_hour >= 12)
|
|
msm6242_write(priv, MSM6242_HOUR10_PM + (tm->tm_hour - 12) / 10,
|
|
MSM6242_HOUR10);
|
|
else
|
|
msm6242_write(priv, tm->tm_hour / 10, MSM6242_HOUR10);
|
|
msm6242_write(priv, tm->tm_hour % 10, MSM6242_HOUR1);
|
|
msm6242_write(priv, tm->tm_mday / 10, MSM6242_DAY10);
|
|
msm6242_write(priv, tm->tm_mday % 10, MSM6242_DAY1);
|
|
if (tm->tm_wday != -1)
|
|
msm6242_write(priv, tm->tm_wday, MSM6242_WEEK);
|
|
msm6242_write(priv, (tm->tm_mon + 1) / 10, MSM6242_MONTH10);
|
|
msm6242_write(priv, (tm->tm_mon + 1) % 10, MSM6242_MONTH1);
|
|
if (tm->tm_year >= 100)
|
|
tm->tm_year -= 100;
|
|
msm6242_write(priv, tm->tm_year / 10, MSM6242_YEAR10);
|
|
msm6242_write(priv, tm->tm_year % 10, MSM6242_YEAR1);
|
|
|
|
msm6242_unlock(priv);
|
|
return 0;
|
|
}
|
|
|
|
static const struct rtc_class_ops msm6242_rtc_ops = {
|
|
.read_time = msm6242_read_time,
|
|
.set_time = msm6242_set_time,
|
|
};
|
|
|
|
static int __init msm6242_rtc_probe(struct platform_device *dev)
|
|
{
|
|
struct resource *res;
|
|
struct msm6242_priv *priv;
|
|
struct rtc_device *rtc;
|
|
int error;
|
|
|
|
res = platform_get_resource(dev, IORESOURCE_MEM, 0);
|
|
if (!res)
|
|
return -ENODEV;
|
|
|
|
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
|
|
if (!priv)
|
|
return -ENOMEM;
|
|
|
|
priv->regs = ioremap(res->start, resource_size(res));
|
|
if (!priv->regs) {
|
|
error = -ENOMEM;
|
|
goto out_free_priv;
|
|
}
|
|
platform_set_drvdata(dev, priv);
|
|
|
|
rtc = rtc_device_register("rtc-msm6242", &dev->dev, &msm6242_rtc_ops,
|
|
THIS_MODULE);
|
|
if (IS_ERR(rtc)) {
|
|
error = PTR_ERR(rtc);
|
|
goto out_unmap;
|
|
}
|
|
|
|
priv->rtc = rtc;
|
|
return 0;
|
|
|
|
out_unmap:
|
|
platform_set_drvdata(dev, NULL);
|
|
iounmap(priv->regs);
|
|
out_free_priv:
|
|
kfree(priv);
|
|
return error;
|
|
}
|
|
|
|
static int __exit msm6242_rtc_remove(struct platform_device *dev)
|
|
{
|
|
struct msm6242_priv *priv = platform_get_drvdata(dev);
|
|
|
|
rtc_device_unregister(priv->rtc);
|
|
iounmap(priv->regs);
|
|
kfree(priv);
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver msm6242_rtc_driver = {
|
|
.driver = {
|
|
.name = "rtc-msm6242",
|
|
.owner = THIS_MODULE,
|
|
},
|
|
.remove = __exit_p(msm6242_rtc_remove),
|
|
};
|
|
|
|
static int __init msm6242_rtc_init(void)
|
|
{
|
|
return platform_driver_probe(&msm6242_rtc_driver, msm6242_rtc_probe);
|
|
}
|
|
|
|
static void __exit msm6242_rtc_fini(void)
|
|
{
|
|
platform_driver_unregister(&msm6242_rtc_driver);
|
|
}
|
|
|
|
module_init(msm6242_rtc_init);
|
|
module_exit(msm6242_rtc_fini);
|
|
|
|
MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("Oki MSM6242 RTC driver");
|
|
MODULE_ALIAS("platform:rtc-msm6242");
|