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[PATCH] hwmon: Separate the lm90 register read function
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Preparatory patch to add PEC support to the lm90 driver. We need a
centralized function to read register values, where the PEC code will
be later inserted. A positive side effect is that read errors are now
handled properly.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Jean Delvare authored and Greg Kroah-Hartman committed Oct 28, 2005
1 parent e8aac4a commit 8256fe0
Showing 1 changed file with 53 additions and 54 deletions.
107 changes: 53 additions & 54 deletions drivers/hwmon/lm90.c
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Original file line number Diff line number Diff line change
Expand Up @@ -349,6 +349,22 @@ static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
* Real code
*/

static int lm90_read_reg(struct i2c_client* client, u8 reg, u8 *value)
{
int err;

err = i2c_smbus_read_byte_data(client, reg);

if (err < 0) {
dev_warn(&client->dev, "Register %#02x read failed (%d)\n",
reg, err);
return err;
}
*value = err;

return 0;
}

static int lm90_attach_adapter(struct i2c_adapter *adapter)
{
if (!(adapter->class & I2C_CLASS_HWMON))
Expand Down Expand Up @@ -402,20 +418,22 @@ static int lm90_detect(struct i2c_adapter *adapter, int address, int kind)
if (kind < 0) { /* detection and identification */
u8 man_id, chip_id, reg_config1, reg_convrate;

man_id = i2c_smbus_read_byte_data(new_client,
LM90_REG_R_MAN_ID);
chip_id = i2c_smbus_read_byte_data(new_client,
LM90_REG_R_CHIP_ID);
reg_config1 = i2c_smbus_read_byte_data(new_client,
LM90_REG_R_CONFIG1);
reg_convrate = i2c_smbus_read_byte_data(new_client,
LM90_REG_R_CONVRATE);
if (lm90_read_reg(new_client, LM90_REG_R_MAN_ID,
&man_id) < 0
|| lm90_read_reg(new_client, LM90_REG_R_CHIP_ID,
&chip_id) < 0
|| lm90_read_reg(new_client, LM90_REG_R_CONFIG1,
&reg_config1) < 0
|| lm90_read_reg(new_client, LM90_REG_R_CONVRATE,
&reg_convrate) < 0)
goto exit_free;

if (man_id == 0x01) { /* National Semiconductor */
u8 reg_config2;

reg_config2 = i2c_smbus_read_byte_data(new_client,
LM90_REG_R_CONFIG2);
if (lm90_read_reg(new_client, LM90_REG_R_CONFIG2,
&reg_config2) < 0)
goto exit_free;

if ((reg_config1 & 0x2A) == 0x00
&& (reg_config2 & 0xF8) == 0x00
Expand Down Expand Up @@ -547,7 +565,10 @@ static void lm90_init_client(struct i2c_client *client)
*/
i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
5); /* 2 Hz */
config = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG1);
if (lm90_read_reg(client, LM90_REG_R_CONFIG1, &config) < 0) {
dev_warn(&client->dev, "Initialization failed!\n");
return;
}
if (config & 0x40)
i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
config & 0xBF); /* run */
Expand Down Expand Up @@ -575,21 +596,15 @@ static struct lm90_data *lm90_update_device(struct device *dev)
down(&data->update_lock);

if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
u8 oldh, newh;
u8 oldh, newh, l;

dev_dbg(&client->dev, "Updating lm90 data.\n");
data->temp8[0] = i2c_smbus_read_byte_data(client,
LM90_REG_R_LOCAL_TEMP);
data->temp8[1] = i2c_smbus_read_byte_data(client,
LM90_REG_R_LOCAL_LOW);
data->temp8[2] = i2c_smbus_read_byte_data(client,
LM90_REG_R_LOCAL_HIGH);
data->temp8[3] = i2c_smbus_read_byte_data(client,
LM90_REG_R_LOCAL_CRIT);
data->temp8[4] = i2c_smbus_read_byte_data(client,
LM90_REG_R_REMOTE_CRIT);
data->temp_hyst = i2c_smbus_read_byte_data(client,
LM90_REG_R_TCRIT_HYST);
lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP, &data->temp8[0]);
lm90_read_reg(client, LM90_REG_R_LOCAL_LOW, &data->temp8[1]);
lm90_read_reg(client, LM90_REG_R_LOCAL_HIGH, &data->temp8[2]);
lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT, &data->temp8[3]);
lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[4]);
lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);

/*
* There is a trick here. We have to read two registers to
Expand All @@ -605,36 +620,20 @@ static struct lm90_data *lm90_update_device(struct device *dev)
* then we have a valid reading. Else we have to read the low
* byte again, and now we believe we have a correct reading.
*/
oldh = i2c_smbus_read_byte_data(client,
LM90_REG_R_REMOTE_TEMPH);
data->temp11[0] = i2c_smbus_read_byte_data(client,
LM90_REG_R_REMOTE_TEMPL);
newh = i2c_smbus_read_byte_data(client,
LM90_REG_R_REMOTE_TEMPH);
if (newh != oldh) {
data->temp11[0] = i2c_smbus_read_byte_data(client,
LM90_REG_R_REMOTE_TEMPL);
#ifdef DEBUG
oldh = i2c_smbus_read_byte_data(client,
LM90_REG_R_REMOTE_TEMPH);
/* oldh is actually newer */
if (newh != oldh)
dev_warn(&client->dev, "Remote temperature may be "
"wrong.\n");
#endif
}
data->temp11[0] |= (newh << 8);

data->temp11[1] = (i2c_smbus_read_byte_data(client,
LM90_REG_R_REMOTE_LOWH) << 8) +
i2c_smbus_read_byte_data(client,
LM90_REG_R_REMOTE_LOWL);
data->temp11[2] = (i2c_smbus_read_byte_data(client,
LM90_REG_R_REMOTE_HIGHH) << 8) +
i2c_smbus_read_byte_data(client,
LM90_REG_R_REMOTE_HIGHL);
data->alarms = i2c_smbus_read_byte_data(client,
LM90_REG_R_STATUS);
if (lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPH, &oldh) == 0
&& lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPL, &l) == 0
&& lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPH, &newh) == 0
&& (newh == oldh
|| lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPL, &l) == 0))
data->temp11[0] = (newh << 8) | l;

if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &newh) == 0
&& lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL, &l) == 0)
data->temp11[1] = (newh << 8) | l;
if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &newh) == 0
&& lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL, &l) == 0)
data->temp11[2] = (newh << 8) | l;
lm90_read_reg(client, LM90_REG_R_STATUS, &data->alarms);

data->last_updated = jiffies;
data->valid = 1;
Expand Down

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