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rtc-ds1307 becomes new-style i2c driver
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Convert the rtc-ds1307 driver into a "new style" driver.

Also improve probe() checks:  be more correct about switching out of
AM/PM mode, and issue a (debug) diagnostic when failing due to bogus
register values.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Andrew Victor <andrew@sanpeople.com>
Cc: Bill Gatliff <bgat@billgatliff.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@gate.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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David Brownell authored and Linus Torvalds committed Jul 17, 2007
1 parent be5f59f commit c065f35
Showing 1 changed file with 53 additions and 75 deletions.
128 changes: 53 additions & 75 deletions drivers/rtc/rtc-ds1307.c
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Original file line number Diff line number Diff line change
Expand Up @@ -27,13 +27,8 @@
* This is currently a simple no-alarms driver. If your board has the
* alarm irq wired up on a ds1337 or ds1339, and you want to use that,
* then look at the rtc-rs5c372 driver for code to steal...
*
* If the I2C "force" mechanism is used, we assume the chip is a ds1337.
* (Much better would be board-specific tables of I2C devices, along with
* the platform_data drivers would use to sort such issues out.)
*/
enum ds_type {
unknown = 0,
ds_1307,
ds_1337,
ds_1338,
Expand All @@ -43,18 +38,15 @@ enum ds_type {
// rs5c372 too? different address...
};

static unsigned short normal_i2c[] = { 0x68, I2C_CLIENT_END };

I2C_CLIENT_INSMOD;



/* RTC registers don't differ much, except for the century flag */
#define DS1307_REG_SECS 0x00 /* 00-59 */
# define DS1307_BIT_CH 0x80
# define DS1340_BIT_nEOSC 0x80
#define DS1307_REG_MIN 0x01 /* 00-59 */
#define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
# define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
# define DS1307_BIT_PM 0x20 /* in REG_HOUR */
# define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
# define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
#define DS1307_REG_WDAY 0x03 /* 01-07 */
Expand Down Expand Up @@ -252,39 +244,27 @@ static const struct rtc_class_ops ds13xx_rtc_ops = {

static struct i2c_driver ds1307_driver;

static int __devinit
ds1307_detect(struct i2c_adapter *adapter, int address, int kind)
static int __devinit ds1307_probe(struct i2c_client *client)
{
struct ds1307 *ds1307;
int err = -ENODEV;
struct i2c_client *client;
int tmp;
const struct chip_desc *chip;
struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);

if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL))) {
err = -ENOMEM;
goto exit;
chip = find_chip(client->name);
if (!chip) {
dev_err(&client->dev, "unknown chip type '%s'\n",
client->name);
return -ENODEV;
}

/* REVISIT: pending driver model conversion, set up "client"
* ourselves, and use a hack to determine the RTC type (instead
* of reading the client->name we're given)
*/
client = &ds1307->dev;
client->addr = address;
client->adapter = adapter;
client->driver = &ds1307_driver;

/* HACK: "force" implies "needs ds1337-style-oscillator setup", and
* that's the only kind of chip setup we'll know about. Until the
* driver model conversion, here's where to add any board-specific
* code to say what kind of chip is present...
*/
if (kind >= 0)
chip = find_chip("ds1337");
else
chip = find_chip("ds1307");
strlcpy(client->name, chip->name, I2C_NAME_SIZE);
if (!i2c_check_functionality(adapter,
I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
return -EIO;

if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL)))
return -ENOMEM;

ds1307->client = client;
i2c_set_clientdata(client, ds1307);
Expand Down Expand Up @@ -378,94 +358,92 @@ ds1307_detect(struct i2c_adapter *adapter, int address, int kind)
goto read_rtc;
}
break;
default:
case ds_1337:
case ds_1339:
break;
}

tmp = ds1307->regs[DS1307_REG_SECS];
tmp = BCD2BIN(tmp & 0x7f);
if (tmp > 60)
goto exit_free;
goto exit_bad;
tmp = BCD2BIN(ds1307->regs[DS1307_REG_MIN] & 0x7f);
if (tmp > 60)
goto exit_free;
goto exit_bad;

tmp = BCD2BIN(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
if (tmp == 0 || tmp > 31)
goto exit_free;
goto exit_bad;

tmp = BCD2BIN(ds1307->regs[DS1307_REG_MONTH] & 0x1f);
if (tmp == 0 || tmp > 12)
goto exit_free;
goto exit_bad;

/* force into in 24 hour mode (most chips) or
* disable century bit (ds1340)
*
* REVISIT forcing 24 hour mode can prevent multi-master
* configs from sharing this RTC ... don't do this.
* The clock needs to be reset after changing it, too...
*/
tmp = ds1307->regs[DS1307_REG_HOUR];
if (tmp & (1 << 6)) {
if (tmp & (1 << 5))
tmp = BCD2BIN(tmp & 0x1f) + 12;
else
tmp = BCD2BIN(tmp);
switch (ds1307->type) {
case ds_1340:
case m41t00:
/* NOTE: ignores century bits; fix before deploying
* systems that will run through year 2100.
*/
break;
default:
if (!(tmp & DS1307_BIT_12HR))
break;

/* Be sure we're in 24 hour mode. Multi-master systems
* take note...
*/
tmp = BCD2BIN(tmp & 0x1f);
if (tmp == 12)
tmp = 0;
if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
tmp += 12;
i2c_smbus_write_byte_data(client,
DS1307_REG_HOUR,
BIN2BCD(tmp));
}

/* Tell the I2C layer a new client has arrived */
if ((err = i2c_attach_client(client)))
goto exit_free;

ds1307->rtc = rtc_device_register(client->name, &client->dev,
&ds13xx_rtc_ops, THIS_MODULE);
if (IS_ERR(ds1307->rtc)) {
err = PTR_ERR(ds1307->rtc);
dev_err(&client->dev,
"unable to register the class device\n");
goto exit_detach;
goto exit_free;
}

return 0;

exit_detach:
i2c_detach_client(client);
exit_bad:
dev_dbg(&client->dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
"bogus register",
ds1307->regs[0], ds1307->regs[1],
ds1307->regs[2], ds1307->regs[3],
ds1307->regs[4], ds1307->regs[5],
ds1307->regs[6]);

exit_free:
kfree(ds1307);
exit:
return err;
}

static int __devinit
ds1307_attach_adapter(struct i2c_adapter *adapter)
{
if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
return 0;
return i2c_probe(adapter, &addr_data, ds1307_detect);
}

static int __devexit ds1307_detach_client(struct i2c_client *client)
static int __devexit ds1307_remove(struct i2c_client *client)
{
int err;
struct ds1307 *ds1307 = i2c_get_clientdata(client);

rtc_device_unregister(ds1307->rtc);
if ((err = i2c_detach_client(client)))
return err;
kfree(ds1307);
return 0;
}

static struct i2c_driver ds1307_driver = {
.driver = {
.name = "ds1307",
.name = "rtc-ds1307",
.owner = THIS_MODULE,
},
.attach_adapter = ds1307_attach_adapter,
.detach_client = __devexit_p(ds1307_detach_client),
.probe = ds1307_probe,
.remove = __devexit_p(ds1307_remove),
};

static int __init ds1307_init(void)
Expand Down

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