[PATCH] I2C fixes for 2.6.10-rc2

From: Greg KH
Date: Fri Nov 19 2004 - 17:26:03 EST


ChangeSet 1.2164, 2004/11/19 09:12:35-08:00, khali@xxxxxxxxxxxx

[PATCH] I2C: Do not register useless smsc47m1

While verifying my stack of patches against what you sent to Linus last
week, I noticed this one. Looks like I simply forgot to send it to you,
as I cannot find any trace of it in the lm_sensors mailing-list
archives.

The patch prevents an smsc47m1 device from being registered when no
monitoring function is actually active within the chip. See this ticket
for background:
http://secure.netroedge.com/~lm78/readticket.cgi?ticket=1801
This is certainly better to explicitely fail in this case than leave the
user with an empty sysfs directory (except for alarms), which tends to
make him/her think of a driver bug, which it isn't (what it really is is
a BIOS brokenness).

Signed-off-by: Jean Delvare <khali@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <greg@xxxxxxxxx>


drivers/i2c/chips/smsc47m1.c | 29 +++++++++++++++++++++--------
1 files changed, 21 insertions(+), 8 deletions(-)


diff -Nru a/drivers/i2c/chips/smsc47m1.c b/drivers/i2c/chips/smsc47m1.c
--- a/drivers/i2c/chips/smsc47m1.c 2004-11-19 11:40:54 -08:00
+++ b/drivers/i2c/chips/smsc47m1.c 2004-11-19 11:40:54 -08:00
@@ -394,6 +394,7 @@
struct i2c_client *new_client;
struct smsc47m1_data *data;
int err = 0;
+ int fan1, fan2, pwm1, pwm2;

if (!i2c_is_isa_adapter(adapter)) {
return 0;
@@ -423,6 +424,22 @@
new_client->id = smsc47m1_id++;
init_MUTEX(&data->update_lock);

+ /* If no function is properly configured, there's no point in
+ actually registering the chip. */
+ fan1 = (smsc47m1_read_value(new_client, SMSC47M1_REG_TPIN(0)) & 0x05)
+ == 0x05;
+ fan2 = (smsc47m1_read_value(new_client, SMSC47M1_REG_TPIN(1)) & 0x05)
+ == 0x05;
+ pwm1 = (smsc47m1_read_value(new_client, SMSC47M1_REG_PPIN(0)) & 0x05)
+ == 0x04;
+ pwm2 = (smsc47m1_read_value(new_client, SMSC47M1_REG_PPIN(1)) & 0x05)
+ == 0x04;
+ if (!(fan1 || fan2 || pwm1 || pwm2)) {
+ dev_warn(&new_client->dev, "Device is not configured, will not use\n");
+ err = -ENODEV;
+ goto error_free;
+ }
+
if ((err = i2c_attach_client(new_client)))
goto error_free;

@@ -434,8 +451,7 @@
function. */
smsc47m1_update_device(&new_client->dev, 1);

- if ((smsc47m1_read_value(new_client, SMSC47M1_REG_TPIN(0)) & 0x05)
- == 0x05) {
+ if (fan1) {
device_create_file(&new_client->dev, &dev_attr_fan1_input);
device_create_file(&new_client->dev, &dev_attr_fan1_min);
device_create_file(&new_client->dev, &dev_attr_fan1_div);
@@ -443,8 +459,7 @@
dev_dbg(&new_client->dev, "Fan 1 not enabled by hardware, "
"skipping\n");

- if ((smsc47m1_read_value(new_client, SMSC47M1_REG_TPIN(1)) & 0x05)
- == 0x05) {
+ if (fan2) {
device_create_file(&new_client->dev, &dev_attr_fan2_input);
device_create_file(&new_client->dev, &dev_attr_fan2_min);
device_create_file(&new_client->dev, &dev_attr_fan2_div);
@@ -452,15 +467,13 @@
dev_dbg(&new_client->dev, "Fan 2 not enabled by hardware, "
"skipping\n");

- if ((smsc47m1_read_value(new_client, SMSC47M1_REG_PPIN(0)) & 0x05)
- == 0x04) {
+ if (pwm1) {
device_create_file(&new_client->dev, &dev_attr_pwm1);
device_create_file(&new_client->dev, &dev_attr_pwm1_enable);
} else
dev_dbg(&new_client->dev, "PWM 1 not enabled by hardware, "
"skipping\n");
- if ((smsc47m1_read_value(new_client, SMSC47M1_REG_PPIN(1)) & 0x05)
- == 0x04) {
+ if (pwm2) {
device_create_file(&new_client->dev, &dev_attr_pwm2);
device_create_file(&new_client->dev, &dev_attr_pwm2_enable);
} else
-
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