/*
- * I2C client/driver for the ST M41T00 family of i2c rtc chips.
+ * drivers/i2c/chips/m41t00.c
+ *
+ * I2C client/driver for the ST M41T00 Real-Time Clock chip.
*
* Author: Mark A. Greer <mgreer@mvista.com>
*
- * 2005, 2006 (c) MontaVista Software, Inc. This file is licensed under
+ * 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/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>
+#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[] = { I2C_CLIENT_END, 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,
+ .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,
- },
- };
+ 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 (i2c_transfer(save_client->adapter, msgs, 2) < 0)
- goto read_err;
+ 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;
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 = 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);
+ 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);
-
-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)
+m41t00_set_tlet(ulong 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,
- },
- };
+ ulong nowtime = *(ulong *)arg;
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");
+ 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 & 0x3f)
+ < 0)
+ || (i2c_smbus_write_byte_data(save_client, 4, tm.tm_mday & 0x3f)
+ < 0)
+ || (i2c_smbus_write_byte_data(save_client, 5, tm.tm_mon & 0x1f)
+ < 0)
+ || (i2c_smbus_write_byte_data(save_client, 6, tm.tm_year & 0xff)
+ < 0))
+
+ dev_warn(&save_client->dev,"m41t00: can't write to rtc chip\n");
+
+ up(&m41t00_mutex);
+ return;
}
-static ulong new_time;
-static struct workqueue_struct *m41t00_wq;
-static DECLARE_WORK(m41t00_work, m41t00_set, &new_time);
+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())
- queue_work(m41t00_wq, &m41t00_work);
+ tasklet_schedule(&m41t00_tasklet);
else
- m41t00_set(&new_time);
+ m41t00_set_tlet((ulong)&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,
- },
-};
/*
*****************************************************************************
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);
+ strncpy(client->name, M41T00_DRV_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;
+ if ((rc = i2c_attach_client(client)) != 0) {
+ kfree(client);
+ return rc;
}
- /* 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
static int
m41t00_detach(struct i2c_client *client)
{
- int rc;
+ int rc;
if ((rc = i2c_detach_client(client)) == 0) {
kfree(client);
- destroy_workqueue(m41t00_wq);
+ tasklet_kill(&m41t00_tasklet);
}
return rc;
}
static int __init
m41t00_init(void)
{
- int rc;
-
- if (!(rc = platform_driver_register(&m41t00_platform_driver)))
- rc = i2c_add_driver(&m41t00_driver);
- return rc;
+ return i2c_add_driver(&m41t00_driver);
}
static void __exit
m41t00_exit(void)
{
i2c_del_driver(&m41t00_driver);
- platform_driver_unregister(&m41t00_platform_driver);
+ return;
}
module_init(m41t00_init);
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