![Mark A. Greer](/assets/img/avatar_default.png)
The 'new_time' variable should be static. Signed-off-by: Mark A. Greer <mgreer@mvista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
243 lines
5.3 KiB
C
243 lines
5.3 KiB
C
/*
|
|
* drivers/i2c/chips/m41t00.c
|
|
*
|
|
* I2C client/driver for the ST M41T00 Real-Time Clock chip.
|
|
*
|
|
* Author: Mark A. Greer <mgreer@mvista.com>
|
|
*
|
|
* 2005 (c) MontaVista Software, Inc. This file is licensed under
|
|
* the terms of the GNU General Public License version 2. This program
|
|
* is licensed "as is" without any warranty of any kind, whether express
|
|
* or implied.
|
|
*/
|
|
/*
|
|
* This i2c client/driver wedges between the drivers/char/genrtc.c RTC
|
|
* interface and the SMBus interface of the i2c subsystem.
|
|
* It would be more efficient to use i2c msgs/i2c_transfer directly but, as
|
|
* recommened in .../Documentation/i2c/writing-clients section
|
|
* "Sending and receiving", using SMBus level communication is preferred.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/bcd.h>
|
|
|
|
#include <asm/time.h>
|
|
#include <asm/rtc.h>
|
|
|
|
#define M41T00_DRV_NAME "m41t00"
|
|
|
|
static DECLARE_MUTEX(m41t00_mutex);
|
|
|
|
static struct i2c_driver m41t00_driver;
|
|
static struct i2c_client *save_client;
|
|
|
|
static unsigned short ignore[] = { I2C_CLIENT_END };
|
|
static unsigned short normal_addr[] = { 0x68, I2C_CLIENT_END };
|
|
|
|
static struct i2c_client_address_data addr_data = {
|
|
.normal_i2c = normal_addr,
|
|
.probe = ignore,
|
|
.ignore = ignore,
|
|
};
|
|
|
|
ulong
|
|
m41t00_get_rtc_time(void)
|
|
{
|
|
s32 sec, min, hour, day, mon, year;
|
|
s32 sec1, min1, hour1, day1, mon1, year1;
|
|
ulong limit = 10;
|
|
|
|
sec = min = hour = day = mon = year = 0;
|
|
sec1 = min1 = hour1 = day1 = mon1 = year1 = 0;
|
|
|
|
down(&m41t00_mutex);
|
|
do {
|
|
if (((sec = i2c_smbus_read_byte_data(save_client, 0)) >= 0)
|
|
&& ((min = i2c_smbus_read_byte_data(save_client, 1))
|
|
>= 0)
|
|
&& ((hour = i2c_smbus_read_byte_data(save_client, 2))
|
|
>= 0)
|
|
&& ((day = i2c_smbus_read_byte_data(save_client, 4))
|
|
>= 0)
|
|
&& ((mon = i2c_smbus_read_byte_data(save_client, 5))
|
|
>= 0)
|
|
&& ((year = i2c_smbus_read_byte_data(save_client, 6))
|
|
>= 0)
|
|
&& ((sec == sec1) && (min == min1) && (hour == hour1)
|
|
&& (day == day1) && (mon == mon1)
|
|
&& (year == year1)))
|
|
|
|
break;
|
|
|
|
sec1 = sec;
|
|
min1 = min;
|
|
hour1 = hour;
|
|
day1 = day;
|
|
mon1 = mon;
|
|
year1 = year;
|
|
} while (--limit > 0);
|
|
up(&m41t00_mutex);
|
|
|
|
if (limit == 0) {
|
|
dev_warn(&save_client->dev,
|
|
"m41t00: can't read rtc chip\n");
|
|
sec = min = hour = day = mon = year = 0;
|
|
}
|
|
|
|
sec &= 0x7f;
|
|
min &= 0x7f;
|
|
hour &= 0x3f;
|
|
day &= 0x3f;
|
|
mon &= 0x1f;
|
|
year &= 0xff;
|
|
|
|
BCD_TO_BIN(sec);
|
|
BCD_TO_BIN(min);
|
|
BCD_TO_BIN(hour);
|
|
BCD_TO_BIN(day);
|
|
BCD_TO_BIN(mon);
|
|
BCD_TO_BIN(year);
|
|
|
|
year += 1900;
|
|
if (year < 1970)
|
|
year += 100;
|
|
|
|
return mktime(year, mon, day, hour, min, sec);
|
|
}
|
|
|
|
static void
|
|
m41t00_set_tlet(ulong arg)
|
|
{
|
|
struct rtc_time tm;
|
|
ulong nowtime = *(ulong *)arg;
|
|
|
|
to_tm(nowtime, &tm);
|
|
tm.tm_year = (tm.tm_year - 1900) % 100;
|
|
|
|
BIN_TO_BCD(tm.tm_sec);
|
|
BIN_TO_BCD(tm.tm_min);
|
|
BIN_TO_BCD(tm.tm_hour);
|
|
BIN_TO_BCD(tm.tm_mon);
|
|
BIN_TO_BCD(tm.tm_mday);
|
|
BIN_TO_BCD(tm.tm_year);
|
|
|
|
down(&m41t00_mutex);
|
|
if ((i2c_smbus_write_byte_data(save_client, 0, tm.tm_sec & 0x7f) < 0)
|
|
|| (i2c_smbus_write_byte_data(save_client, 1, tm.tm_min & 0x7f)
|
|
< 0)
|
|
|| (i2c_smbus_write_byte_data(save_client, 2, tm.tm_hour & 0x7f)
|
|
< 0)
|
|
|| (i2c_smbus_write_byte_data(save_client, 4, tm.tm_mday & 0x7f)
|
|
< 0)
|
|
|| (i2c_smbus_write_byte_data(save_client, 5, tm.tm_mon & 0x7f)
|
|
< 0)
|
|
|| (i2c_smbus_write_byte_data(save_client, 6, tm.tm_year & 0x7f)
|
|
< 0))
|
|
|
|
dev_warn(&save_client->dev,"m41t00: can't write to rtc chip\n");
|
|
|
|
up(&m41t00_mutex);
|
|
return;
|
|
}
|
|
|
|
static ulong new_time;
|
|
|
|
DECLARE_TASKLET_DISABLED(m41t00_tasklet, m41t00_set_tlet, (ulong)&new_time);
|
|
|
|
int
|
|
m41t00_set_rtc_time(ulong nowtime)
|
|
{
|
|
new_time = nowtime;
|
|
|
|
if (in_interrupt())
|
|
tasklet_schedule(&m41t00_tasklet);
|
|
else
|
|
m41t00_set_tlet((ulong)&new_time);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
*****************************************************************************
|
|
*
|
|
* Driver Interface
|
|
*
|
|
*****************************************************************************
|
|
*/
|
|
static int
|
|
m41t00_probe(struct i2c_adapter *adap, int addr, int kind)
|
|
{
|
|
struct i2c_client *client;
|
|
int rc;
|
|
|
|
client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
|
|
if (!client)
|
|
return -ENOMEM;
|
|
|
|
memset(client, 0, sizeof(struct i2c_client));
|
|
strncpy(client->name, M41T00_DRV_NAME, I2C_NAME_SIZE);
|
|
client->flags = I2C_DF_NOTIFY;
|
|
client->addr = addr;
|
|
client->adapter = adap;
|
|
client->driver = &m41t00_driver;
|
|
|
|
if ((rc = i2c_attach_client(client)) != 0) {
|
|
kfree(client);
|
|
return rc;
|
|
}
|
|
|
|
save_client = client;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
m41t00_attach(struct i2c_adapter *adap)
|
|
{
|
|
return i2c_probe(adap, &addr_data, m41t00_probe);
|
|
}
|
|
|
|
static int
|
|
m41t00_detach(struct i2c_client *client)
|
|
{
|
|
int rc;
|
|
|
|
if ((rc = i2c_detach_client(client)) == 0) {
|
|
kfree(client);
|
|
tasklet_kill(&m41t00_tasklet);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
static struct i2c_driver m41t00_driver = {
|
|
.owner = THIS_MODULE,
|
|
.name = M41T00_DRV_NAME,
|
|
.id = I2C_DRIVERID_STM41T00,
|
|
.flags = I2C_DF_NOTIFY,
|
|
.attach_adapter = m41t00_attach,
|
|
.detach_client = m41t00_detach,
|
|
};
|
|
|
|
static int __init
|
|
m41t00_init(void)
|
|
{
|
|
return i2c_add_driver(&m41t00_driver);
|
|
}
|
|
|
|
static void __exit
|
|
m41t00_exit(void)
|
|
{
|
|
i2c_del_driver(&m41t00_driver);
|
|
return;
|
|
}
|
|
|
|
module_init(m41t00_init);
|
|
module_exit(m41t00_exit);
|
|
|
|
MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
|
|
MODULE_DESCRIPTION("ST Microelectronics M41T00 RTC I2C Client Driver");
|
|
MODULE_LICENSE("GPL");
|