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linux/drivers/rtc/rtc-s35390a.c
Wolfram Sang fbae3fb154 i2c: Remove all i2c_set_clientdata(client, NULL) in drivers 
I2C drivers can use the clientdata-pointer to point to private data. As I2C
devices are not really unregistered, but merely detached from their driver, it
used to be the drivers obligation to clear this pointer during remove() or a
failed probe(). As a couple of drivers forgot to do this, it was agreed that it
was cleaner if the i2c-core does this clearance when appropriate, as there is
no guarantee for the lifetime of the clientdata-pointer after remove() anyhow.
This feature was added to the core with commit
e4a7b9b04d to fix the faulty drivers.

As there is no need anymore to clear the clientdata-pointer, remove all current
occurrences in the drivers to simplify the code and prevent confusion.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Richard Purdie <rpurdie@linux.intel.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-06-03 11:33:58 +02:00

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/*
* Seiko Instruments S-35390A RTC Driver
*
* Copyright (c) 2007 Byron Bradley
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/i2c.h>
#include <linux/bitrev.h>
#include <linux/bcd.h>
#include <linux/slab.h>
#define S35390A_CMD_STATUS1 0
#define S35390A_CMD_STATUS2 1
#define S35390A_CMD_TIME1 2
#define S35390A_BYTE_YEAR 0
#define S35390A_BYTE_MONTH 1
#define S35390A_BYTE_DAY 2
#define S35390A_BYTE_WDAY 3
#define S35390A_BYTE_HOURS 4
#define S35390A_BYTE_MINS 5
#define S35390A_BYTE_SECS 6
#define S35390A_FLAG_POC 0x01
#define S35390A_FLAG_BLD 0x02
#define S35390A_FLAG_24H 0x40
#define S35390A_FLAG_RESET 0x80
#define S35390A_FLAG_TEST 0x01
static const struct i2c_device_id s35390a_id[] = {
{ "s35390a", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, s35390a_id);
struct s35390a {
struct i2c_client *client[8];
struct rtc_device *rtc;
int twentyfourhour;
};
static int s35390a_set_reg(struct s35390a *s35390a, int reg, char *buf, int len)
{
struct i2c_client *client = s35390a->client[reg];
struct i2c_msg msg[] = {
{ client->addr, 0, len, buf },
};
if ((i2c_transfer(client->adapter, msg, 1)) != 1)
return -EIO;
return 0;
}
static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len)
{
struct i2c_client *client = s35390a->client[reg];
struct i2c_msg msg[] = {
{ client->addr, I2C_M_RD, len, buf },
};
if ((i2c_transfer(client->adapter, msg, 1)) != 1)
return -EIO;
return 0;
}
static int s35390a_reset(struct s35390a *s35390a)
{
char buf[1];
if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)) < 0)
return -EIO;
if (!(buf[0] & (S35390A_FLAG_POC | S35390A_FLAG_BLD)))
return 0;
buf[0] |= (S35390A_FLAG_RESET | S35390A_FLAG_24H);
buf[0] &= 0xf0;
return s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf));
}
static int s35390a_disable_test_mode(struct s35390a *s35390a)
{
char buf[1];
if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0)
return -EIO;
if (!(buf[0] & S35390A_FLAG_TEST))
return 0;
buf[0] &= ~S35390A_FLAG_TEST;
return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf));
}
static char s35390a_hr2reg(struct s35390a *s35390a, int hour)
{
if (s35390a->twentyfourhour)
return bin2bcd(hour);
if (hour < 12)
return bin2bcd(hour);
return 0x40 | bin2bcd(hour - 12);
}
static int s35390a_reg2hr(struct s35390a *s35390a, char reg)
{
unsigned hour;
if (s35390a->twentyfourhour)
return bcd2bin(reg & 0x3f);
hour = bcd2bin(reg & 0x3f);
if (reg & 0x40)
hour += 12;
return hour;
}
static int s35390a_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
struct s35390a *s35390a = i2c_get_clientdata(client);
int i, err;
char buf[7];
dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d mday=%d, "
"mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
tm->tm_wday);
buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100);
buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1);
buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday);
buf[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday);
buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour);
buf[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min);
buf[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec);
/* This chip expects the bits of each byte to be in reverse order */
for (i = 0; i < 7; ++i)
buf[i] = bitrev8(buf[i]);
err = s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
return err;
}
static int s35390a_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
struct s35390a *s35390a = i2c_get_clientdata(client);
char buf[7];
int i, err;
err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
if (err < 0)
return err;
/* This chip returns the bits of each byte in reverse order */
for (i = 0; i < 7; ++i)
buf[i] = bitrev8(buf[i]);
tm->tm_sec = bcd2bin(buf[S35390A_BYTE_SECS]);
tm->tm_min = bcd2bin(buf[S35390A_BYTE_MINS]);
tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]);
tm->tm_wday = bcd2bin(buf[S35390A_BYTE_WDAY]);
tm->tm_mday = bcd2bin(buf[S35390A_BYTE_DAY]);
tm->tm_mon = bcd2bin(buf[S35390A_BYTE_MONTH]) - 1;
tm->tm_year = bcd2bin(buf[S35390A_BYTE_YEAR]) + 100;
dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, "
"mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec,
tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
tm->tm_wday);
return rtc_valid_tm(tm);
}
static int s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
return s35390a_get_datetime(to_i2c_client(dev), tm);
}
static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
return s35390a_set_datetime(to_i2c_client(dev), tm);
}
static const struct rtc_class_ops s35390a_rtc_ops = {
.read_time = s35390a_rtc_read_time,
.set_time = s35390a_rtc_set_time,
};
static struct i2c_driver s35390a_driver;
static int s35390a_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int err;
unsigned int i;
struct s35390a *s35390a;
struct rtc_time tm;
char buf[1];
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
err = -ENODEV;
goto exit;
}
s35390a = kzalloc(sizeof(struct s35390a), GFP_KERNEL);
if (!s35390a) {
err = -ENOMEM;
goto exit;
}
s35390a->client[0] = client;
i2c_set_clientdata(client, s35390a);
/* This chip uses multiple addresses, use dummy devices for them */
for (i = 1; i < 8; ++i) {
s35390a->client[i] = i2c_new_dummy(client->adapter,
client->addr + i);
if (!s35390a->client[i]) {
dev_err(&client->dev, "Address %02x unavailable\n",
client->addr + i);
err = -EBUSY;
goto exit_dummy;
}
}
err = s35390a_reset(s35390a);
if (err < 0) {
dev_err(&client->dev, "error resetting chip\n");
goto exit_dummy;
}
err = s35390a_disable_test_mode(s35390a);
if (err < 0) {
dev_err(&client->dev, "error disabling test mode\n");
goto exit_dummy;
}
err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf));
if (err < 0) {
dev_err(&client->dev, "error checking 12/24 hour mode\n");
goto exit_dummy;
}
if (buf[0] & S35390A_FLAG_24H)
s35390a->twentyfourhour = 1;
else
s35390a->twentyfourhour = 0;
if (s35390a_get_datetime(client, &tm) < 0)
dev_warn(&client->dev, "clock needs to be set\n");
s35390a->rtc = rtc_device_register(s35390a_driver.driver.name,
&client->dev, &s35390a_rtc_ops, THIS_MODULE);
if (IS_ERR(s35390a->rtc)) {
err = PTR_ERR(s35390a->rtc);
goto exit_dummy;
}
return 0;
exit_dummy:
for (i = 1; i < 8; ++i)
if (s35390a->client[i])
i2c_unregister_device(s35390a->client[i]);
kfree(s35390a);
exit:
return err;
}
static int s35390a_remove(struct i2c_client *client)
{
unsigned int i;
struct s35390a *s35390a = i2c_get_clientdata(client);
for (i = 1; i < 8; ++i)
if (s35390a->client[i])
i2c_unregister_device(s35390a->client[i]);
rtc_device_unregister(s35390a->rtc);
kfree(s35390a);
return 0;
}
static struct i2c_driver s35390a_driver = {
.driver = {
.name = "rtc-s35390a",
},
.probe = s35390a_probe,
.remove = s35390a_remove,
.id_table = s35390a_id,
};
static int __init s35390a_rtc_init(void)
{
return i2c_add_driver(&s35390a_driver);
}
static void __exit s35390a_rtc_exit(void)
{
i2c_del_driver(&s35390a_driver);
}
MODULE_AUTHOR("Byron Bradley <byron.bbradley@gmail.com>");
MODULE_DESCRIPTION("S35390A RTC driver");
MODULE_LICENSE("GPL");
module_init(s35390a_rtc_init);
module_exit(s35390a_rtc_exit);
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