Commit c666961d authored by Russell King's avatar Russell King

Add /dev/rtc support for Acorn machines.

parent 36dcfaba
......@@ -14,6 +14,9 @@
*/
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/miscdevice.h>
#include <linux/rtc.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
......@@ -21,15 +24,19 @@
#include <asm/io.h>
#include <asm/hardware/ioc.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include "pcf8583.h"
extern unsigned long
mktime(unsigned int year, unsigned int mon, unsigned int day,
unsigned int hour, unsigned int min, unsigned int sec);
extern int (*set_rtc)(void);
static struct i2c_client *rtc_client;
static const unsigned char days_in_mon[] =
{ 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
static unsigned int rtc_epoch = 1900;
#define CMOS_CHECKSUM (63)
#define CMOS_YEAR (64 + 128)
static inline int rtc_command(int cmd, void *data)
{
......@@ -44,12 +51,10 @@ static inline int rtc_command(int cmd, void *data)
/*
* Read the current RTC time and date, and update xtime.
*/
static void get_rtc_time(void)
static void get_rtc_time(struct rtc_tm *rtctm, unsigned int *year)
{
unsigned char ctrl;
unsigned char year;
struct rtc_tm rtctm;
struct mem rtcmem = { 0xc0, 1, &year };
unsigned char ctrl, yr[2];
struct mem rtcmem = { CMOS_YEAR, sizeof(yr), yr };
/*
* Ensure that the RTC is running.
......@@ -73,22 +78,53 @@ static void get_rtc_time(void)
if (rtc_command(MEM_READ, &rtcmem))
return;
if (rtc_command(RTC_GETDATETIME, &rtctm))
if (rtc_command(RTC_GETDATETIME, rtctm))
return;
if (year < 70)
year += 100;
*year = yr[1] * 100 + yr[0];
}
xtime.tv_usec = rtctm.cs * 10000;
xtime.tv_sec = mktime(1900 + year, rtctm.mon, rtctm.mday,
rtctm.hours, rtctm.mins, rtctm.secs);
static int set_rtc_time(struct rtc_tm *rtctm, unsigned int year)
{
unsigned char yr[2], leap, chk;
struct mem cmos_year = { CMOS_YEAR, sizeof(yr), yr };
struct mem cmos_check = { CMOS_CHECKSUM, 1, &chk };
int ret;
leap = (!(year % 4) && (year % 100)) || !(year % 400);
if (rtctm->mon > 12 || rtctm->mday == 0)
return -EINVAL;
if (rtctm->mday > (days_in_mon[rtctm->mon] + (rtctm->mon == 2 && leap)))
return -EINVAL;
if (rtctm->hours >= 24 || rtctm->mins >= 60 || rtctm->secs >= 60)
return -EINVAL;
ret = rtc_command(RTC_SETDATETIME, rtctm);
if (ret == 0) {
rtc_command(MEM_READ, &cmos_check);
rtc_command(MEM_READ, &cmos_year);
chk -= yr[1] + yr[0];
yr[1] = year / 100;
yr[0] = year % 100;
chk += yr[1] + yr[0];
rtc_command(MEM_WRITE, &cmos_year);
rtc_command(MEM_WRITE, &cmos_check);
}
return ret;
}
/*
* Set the RTC time only. Note that
* we do not touch the date.
*/
static int set_rtc_time(void)
static int k_set_rtc_time(void)
{
struct rtc_tm new_rtctm, old_rtctm;
unsigned long nowtime = xtime.tv_sec;
......@@ -117,6 +153,63 @@ static int set_rtc_time(void)
return rtc_command(RTC_SETTIME, &new_rtctm);
}
static int rtc_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
unsigned int year;
struct rtc_time rtctm;
struct rtc_tm rtc_raw;
switch (cmd) {
case RTC_ALM_READ:
case RTC_ALM_SET:
break;
case RTC_RD_TIME:
get_rtc_time(&rtc_raw, &year);
rtctm.tm_sec = rtc_raw.secs;
rtctm.tm_min = rtc_raw.mins;
rtctm.tm_hour = rtc_raw.hours;
rtctm.tm_mday = rtc_raw.mday;
rtctm.tm_mon = rtc_raw.mon - 1; /* month starts at 0 */
rtctm.tm_year = year - 1900; /* starts at 1900 */
return copy_to_user((void *)arg, &rtctm, sizeof(rtctm))
? -EFAULT : 0;
case RTC_SET_TIME:
if (!capable(CAP_SYS_TIME))
return -EACCES;
if (copy_from_user(&rtctm, (void *)arg, sizeof(rtctm)))
return -EFAULT;
rtc_raw.secs = rtctm.tm_sec;
rtc_raw.mins = rtctm.tm_min;
rtc_raw.hours = rtctm.tm_hour;
rtc_raw.mday = rtctm.tm_mday;
rtc_raw.mon = rtctm.tm_mon + 1;
rtc_raw.year_off = 2;
year = rtctm.tm_year + 1900;
return set_rtc_time(&rtc_raw, year);
break;
case RTC_EPOCH_READ:
return put_user(rtc_epoch, (unsigned long *)arg);
}
return -EINVAL;
}
static struct file_operations rtc_fops = {
ioctl: rtc_ioctl,
};
static struct miscdevice rtc_dev = {
minor: RTC_MINOR,
name: "rtc",
fops: &rtc_fops,
};
/* IOC / IOMD i2c driver */
#define FORCE_ONES 0xdc
#define SCL 0x02
......@@ -184,9 +277,16 @@ static int ioc_client_reg(struct i2c_client *client)
{
if (client->id == I2C_DRIVERID_PCF8583 &&
client->addr == 0x50) {
struct rtc_tm rtctm;
unsigned int year;
rtc_client = client;
get_rtc_time();
set_rtc = set_rtc_time;
get_rtc_time(&rtctm, &year);
xtime.tv_usec = rtctm.cs * 10000;
xtime.tv_sec = mktime(year, rtctm.mon, rtctm.mday,
rtctm.hours, rtctm.mins, rtctm.secs);
set_rtc = k_set_rtc_time;
}
return 0;
......@@ -212,9 +312,16 @@ static struct i2c_adapter ioc_ops = {
static int __init i2c_ioc_init(void)
{
int ret;
force_ones = FORCE_ONES | SCL | SDA;
return i2c_bit_add_bus(&ioc_ops);
ret = i2c_bit_add_bus(&ioc_ops);
if (ret >= 0)
misc_register(&rtc_dev);
return ret;
}
__initcall(i2c_ioc_init);
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