[PATCH] I2C: lm78 driver improvement

Greg KH
2005-03-04T22:06:59Z

ChangeSet 1.2091, 2005/03/02 12:04:28-08:00, aurelien@aurel32.net

[PATCH] I2C: lm78 driver improvement

The following patch against kernel 2.6.11-rc2-mm1 improves the lm78
driver. I used it as a model to port the sis5595 driver to the 2.6
kernel, and I then applied the changes suggested by Jean Delvare on
the sis5595 driver to this one.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/i2c/chips/lm78.c | 53 +++++++++++++++++++++--------------------------
1 files changed, 24 insertions(+), 29 deletions(-)

diff -Nru a/drivers/i2c/chips/lm78.c b/drivers/i2c/chips/lm78.c
--- a/drivers/i2c/chips/lm78.c 2005-03-04 12:25:31 -08:00
+++ b/drivers/i2c/chips/lm78.c 2005-03-04 12:25:31 -08:00
@@ -81,9 +81,8 @@

static inline u8 FAN_TO_REG(long rpm, int div)
{
- if (rpm == 0)
+ if (rpm <= 0)
return 255;
- rpm = SENSORS_LIMIT(rpm, 1, 1000000);
return SENSORS_LIMIT((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
}

@@ -94,15 +93,15 @@

/* TEMP: mC (-128C to +127C)
REG: 1C/bit, two's complement */
-static inline u8 TEMP_TO_REG(int val)
+static inline s8 TEMP_TO_REG(int val)
{
int nval = SENSORS_LIMIT(val, -128000, 127000) ;
- return nval<0 ? (nval-500)/1000+0x100 : (nval+500)/1000;
+ return nval<0 ? (nval-500)/1000 : (nval+500)/1000;
}

-static inline int TEMP_FROM_REG(u8 val)
+static inline int TEMP_FROM_REG(s8 val)
{
- return (val>=0x80 ? val-0x100 : val) * 1000;
+ return val * 1000;
}

/* VID: mV
@@ -112,16 +111,6 @@
return val==0x1f ? 0 : val>=0x10 ? 5100-val*100 : 2050-val*50;
}

-/* ALARMS: chip-specific bitmask
- REG: (same) */
-#define ALARMS_FROM_REG(val) (val)
-
-/* FAN DIV: 1, 2, 4, or 8 (defaults to 2)
- REG: 0, 1, 2, or 3 (respectively) (defaults to 1) */
-static inline u8 DIV_TO_REG(int val)
-{
- return val==8 ? 3 : val==4 ? 2 : val==1 ? 0 : 1;
-}
#define DIV_FROM_REG(val) (1 << (val))

/* There are some complications in a module like this. First off, LM78 chips
@@ -157,9 +146,9 @@
u8 in_min[7]; /* Register value */
u8 fan[3]; /* Register value */
u8 fan_min[3]; /* Register value */
- u8 temp; /* Register value */
- u8 temp_over; /* Register value */
- u8 temp_hyst; /* Register value */
+ s8 temp; /* Register value */
+ s8 temp_over; /* Register value */
+ s8 temp_hyst; /* Register value */
u8 fan_div[3]; /* Register encoding, shifted right */
u8 vid; /* Register encoding, combined */
u16 alarms; /* Register encoding, combined */
@@ -357,7 +346,17 @@
DIV_FROM_REG(data->fan_div[nr]));
unsigned long val = simple_strtoul(buf, NULL, 10);
int reg = lm78_read_value(client, LM78_REG_VID_FANDIV);
- data->fan_div[nr] = DIV_TO_REG(val);
+ switch (val) {
+ case 1: data->fan_div[nr] = 0; break;
+ case 2: data->fan_div[nr] = 1; break;
+ case 4: data->fan_div[nr] = 2; break;
+ case 8: data->fan_div[nr] = 3; break;
+ default:
+ dev_err(&client->dev, "fan_div value %ld not "
+ "supported. Choose one of 1, 2, 4 or 8!\n", val);
+ return -EINVAL;
+ }
+
switch (nr) {
case 0:
reg = (reg & 0xcf) | (data->fan_div[nr] << 4);
@@ -430,7 +429,7 @@
static ssize_t show_alarms(struct device *dev, char *buf)
{
struct lm78_data *data = lm78_update_device(dev);
- return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->alarms));
+ return sprintf(buf, "%u\n", data->alarms);
}
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);

@@ -633,17 +632,15 @@
{
int err;

- /* release ISA region first */
- if(i2c_is_isa_client(client))
- release_region(client->addr, LM78_EXTENT);
-
- /* now it's safe to scrap the rest */
if ((err = i2c_detach_client(client))) {
dev_err(&client->dev,
"Client deregistration failed, client not detached.\n");
return err;
}

+ if(i2c_is_isa_client(client))
+ release_region(client->addr, LM78_EXTENT);
+
kfree(i2c_get_clientdata(client));

return 0;
@@ -653,9 +650,7 @@
We don't want to lock the whole ISA bus, so we lock each client
separately.
We ignore the LM78 BUSY flag at this moment - it could lead to deadlocks,
- would slow down the LM78 access and should not be necessary.
- There are some ugly typecasts here, but the good new is - they should
- nowhere else be necessary! */
+ would slow down the LM78 access and should not be necessary. */
static int lm78_read_value(struct i2c_client *client, u8 reg)
{
int res;