linux/drivers/i2c/chips/m41t00.c

406 lines
9.0 KiB
C

/*
* I2C client/driver for the ST M41T00 family of i2c rtc chips.
*
* Author: Mark A. Greer <mgreer@mvista.com>
*
* 2005, 2006 (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.
*/
#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 <linux/workqueue.h>
#include <linux/platform_device.h>
#include <linux/m41t00.h>
#include <asm/time.h>
#include <asm/rtc.h>
static struct i2c_driver m41t00_driver;
static struct i2c_client *save_client;
static unsigned short ignore[] = { I2C_CLIENT_END };
static unsigned short normal_addr[] = { I2C_CLIENT_END, I2C_CLIENT_END };
static struct i2c_client_address_data addr_data = {
.normal_i2c = normal_addr,
.probe = ignore,
.ignore = ignore,
};
struct m41t00_chip_info {
u8 type;
char *name;
u8 read_limit;
u8 sec; /* Offsets for chip regs */
u8 min;
u8 hour;
u8 day;
u8 mon;
u8 year;
u8 alarm_mon;
u8 alarm_hour;
u8 sqw;
u8 sqw_freq;
};
static struct m41t00_chip_info m41t00_chip_info_tbl[] = {
{
.type = M41T00_TYPE_M41T00,
.name = "m41t00",
.read_limit = 5,
.sec = 0,
.min = 1,
.hour = 2,
.day = 4,
.mon = 5,
.year = 6,
},
{
.type = M41T00_TYPE_M41T81,
.name = "m41t81",
.read_limit = 1,
.sec = 1,
.min = 2,
.hour = 3,
.day = 5,
.mon = 6,
.year = 7,
.alarm_mon = 0xa,
.alarm_hour = 0xc,
.sqw = 0x13,
},
{
.type = M41T00_TYPE_M41T85,
.name = "m41t85",
.read_limit = 1,
.sec = 1,
.min = 2,
.hour = 3,
.day = 5,
.mon = 6,
.year = 7,
.alarm_mon = 0xa,
.alarm_hour = 0xc,
.sqw = 0x13,
},
};
static struct m41t00_chip_info *m41t00_chip;
ulong
m41t00_get_rtc_time(void)
{
s32 sec, min, hour, day, mon, year;
s32 sec1, min1, hour1, day1, mon1, year1;
u8 reads = 0;
u8 buf[8], msgbuf[1] = { 0 }; /* offset into rtc's regs */
struct i2c_msg msgs[] = {
{
.addr = save_client->addr,
.flags = 0,
.len = 1,
.buf = msgbuf,
},
{
.addr = save_client->addr,
.flags = I2C_M_RD,
.len = 8,
.buf = buf,
},
};
sec = min = hour = day = mon = year = 0;
do {
if (i2c_transfer(save_client->adapter, msgs, 2) < 0)
goto read_err;
sec1 = sec;
min1 = min;
hour1 = hour;
day1 = day;
mon1 = mon;
year1 = year;
sec = buf[m41t00_chip->sec] & 0x7f;
min = buf[m41t00_chip->min] & 0x7f;
hour = buf[m41t00_chip->hour] & 0x3f;
day = buf[m41t00_chip->day] & 0x3f;
mon = buf[m41t00_chip->mon] & 0x1f;
year = buf[m41t00_chip->year];
} while ((++reads < m41t00_chip->read_limit) && ((sec != sec1)
|| (min != min1) || (hour != hour1) || (day != day1)
|| (mon != mon1) || (year != year1)));
if ((m41t00_chip->read_limit > 1) && ((sec != sec1) || (min != min1)
|| (hour != hour1) || (day != day1) || (mon != mon1)
|| (year != year1)))
goto read_err;
sec = BCD2BIN(sec);
min = BCD2BIN(min);
hour = BCD2BIN(hour);
day = BCD2BIN(day);
mon = BCD2BIN(mon);
year = BCD2BIN(year);
year += 1900;
if (year < 1970)
year += 100;
return mktime(year, mon, day, hour, min, sec);
read_err:
dev_err(&save_client->dev, "m41t00_get_rtc_time: Read error\n");
return 0;
}
EXPORT_SYMBOL_GPL(m41t00_get_rtc_time);
static void
m41t00_set(void *arg)
{
struct rtc_time tm;
int nowtime = *(int *)arg;
s32 sec, min, hour, day, mon, year;
u8 wbuf[9], *buf = &wbuf[1], msgbuf[1] = { 0 };
struct i2c_msg msgs[] = {
{
.addr = save_client->addr,
.flags = 0,
.len = 1,
.buf = msgbuf,
},
{
.addr = save_client->addr,
.flags = I2C_M_RD,
.len = 8,
.buf = buf,
},
};
to_tm(nowtime, &tm);
tm.tm_year = (tm.tm_year - 1900) % 100;
sec = BIN2BCD(tm.tm_sec);
min = BIN2BCD(tm.tm_min);
hour = BIN2BCD(tm.tm_hour);
day = BIN2BCD(tm.tm_mday);
mon = BIN2BCD(tm.tm_mon);
year = BIN2BCD(tm.tm_year);
/* Read reg values into buf[0..7]/wbuf[1..8] */
if (i2c_transfer(save_client->adapter, msgs, 2) < 0) {
dev_err(&save_client->dev, "m41t00_set: Read error\n");
return;
}
wbuf[0] = 0; /* offset into rtc's regs */
buf[m41t00_chip->sec] = (buf[m41t00_chip->sec] & ~0x7f) | (sec & 0x7f);
buf[m41t00_chip->min] = (buf[m41t00_chip->min] & ~0x7f) | (min & 0x7f);
buf[m41t00_chip->hour] = (buf[m41t00_chip->hour] & ~0x3f) | (hour& 0x3f);
buf[m41t00_chip->day] = (buf[m41t00_chip->day] & ~0x3f) | (day & 0x3f);
buf[m41t00_chip->mon] = (buf[m41t00_chip->mon] & ~0x1f) | (mon & 0x1f);
if (i2c_master_send(save_client, wbuf, 9) < 0)
dev_err(&save_client->dev, "m41t00_set: Write error\n");
}
static ulong new_time;
static struct workqueue_struct *m41t00_wq;
static DECLARE_WORK(m41t00_work, m41t00_set, &new_time);
int
m41t00_set_rtc_time(ulong nowtime)
{
new_time = nowtime;
if (in_interrupt())
queue_work(m41t00_wq, &m41t00_work);
else
m41t00_set(&new_time);
return 0;
}
EXPORT_SYMBOL_GPL(m41t00_set_rtc_time);
/*
*****************************************************************************
*
* platform_data Driver Interface
*
*****************************************************************************
*/
static int __init
m41t00_platform_probe(struct platform_device *pdev)
{
struct m41t00_platform_data *pdata;
int i;
if (pdev && (pdata = pdev->dev.platform_data)) {
normal_addr[0] = pdata->i2c_addr;
for (i=0; i<ARRAY_SIZE(m41t00_chip_info_tbl); i++)
if (m41t00_chip_info_tbl[i].type == pdata->type) {
m41t00_chip = &m41t00_chip_info_tbl[i];
m41t00_chip->sqw_freq = pdata->sqw_freq;
return 0;
}
}
return -ENODEV;
}
static int __exit
m41t00_platform_remove(struct platform_device *pdev)
{
return 0;
}
static struct platform_driver m41t00_platform_driver = {
.probe = m41t00_platform_probe,
.remove = m41t00_platform_remove,
.driver = {
.owner = THIS_MODULE,
.name = M41T00_DRV_NAME,
},
};
/*
*****************************************************************************
*
* Driver Interface
*
*****************************************************************************
*/
static int
m41t00_probe(struct i2c_adapter *adap, int addr, int kind)
{
struct i2c_client *client;
int rc;
if (!i2c_check_functionality(adap, I2C_FUNC_I2C
| I2C_FUNC_SMBUS_BYTE_DATA))
return 0;
client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
if (!client)
return -ENOMEM;
strlcpy(client->name, m41t00_chip->name, I2C_NAME_SIZE);
client->addr = addr;
client->adapter = adap;
client->driver = &m41t00_driver;
if ((rc = i2c_attach_client(client)))
goto attach_err;
if (m41t00_chip->type != M41T00_TYPE_M41T00) {
/* If asked, disable SQW, set SQW frequency & re-enable */
if (m41t00_chip->sqw_freq)
if (((rc = i2c_smbus_read_byte_data(client,
m41t00_chip->alarm_mon)) < 0)
|| ((rc = i2c_smbus_write_byte_data(client,
m41t00_chip->alarm_mon, rc & ~0x40)) <0)
|| ((rc = i2c_smbus_write_byte_data(client,
m41t00_chip->sqw,
m41t00_chip->sqw_freq)) < 0)
|| ((rc = i2c_smbus_write_byte_data(client,
m41t00_chip->alarm_mon, rc | 0x40)) <0))
goto sqw_err;
/* Make sure HT (Halt Update) bit is cleared */
if ((rc = i2c_smbus_read_byte_data(client,
m41t00_chip->alarm_hour)) < 0)
goto ht_err;
if (rc & 0x40)
if ((rc = i2c_smbus_write_byte_data(client,
m41t00_chip->alarm_hour, rc & ~0x40))<0)
goto ht_err;
}
/* Make sure ST (stop) bit is cleared */
if ((rc = i2c_smbus_read_byte_data(client, m41t00_chip->sec)) < 0)
goto st_err;
if (rc & 0x80)
if ((rc = i2c_smbus_write_byte_data(client, m41t00_chip->sec,
rc & ~0x80)) < 0)
goto st_err;
m41t00_wq = create_singlethread_workqueue(m41t00_chip->name);
save_client = client;
return 0;
st_err:
dev_err(&client->dev, "m41t00_probe: Can't clear ST bit\n");
goto attach_err;
ht_err:
dev_err(&client->dev, "m41t00_probe: Can't clear HT bit\n");
goto attach_err;
sqw_err:
dev_err(&client->dev, "m41t00_probe: Can't set SQW Frequency\n");
attach_err:
kfree(client);
return rc;
}
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);
destroy_workqueue(m41t00_wq);
}
return rc;
}
static struct i2c_driver m41t00_driver = {
.driver = {
.name = M41T00_DRV_NAME,
},
.id = I2C_DRIVERID_STM41T00,
.attach_adapter = m41t00_attach,
.detach_client = m41t00_detach,
};
static int __init
m41t00_init(void)
{
int rc;
if (!(rc = platform_driver_register(&m41t00_platform_driver)))
rc = i2c_add_driver(&m41t00_driver);
return rc;
}
static void __exit
m41t00_exit(void)
{
i2c_del_driver(&m41t00_driver);
platform_driver_unregister(&m41t00_platform_driver);
}
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");