hwmon: (lm85) Rework the device detection

Rework the device detection to make it clearer and faster in the
general case (when a known device is found.)

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Herbert Poetzl <herbert@13thfloor.at>

diff --git a/drivers/hwmon/lm85.c b/drivers/hwmon/lm85.c
index 12d446f54f977e5bd68cc0673631dc924bb2ad21..3594a02f281b033f5a577126afa20c422752b3ee 100644 (file)
--- a/drivers/hwmon/lm85.c
+++ b/drivers/hwmon/lm85.c
@@ -1106,7 +1106,6 @@ static void lm85_init_client(struct i2c_client *client)
 static int lm85_detect(struct i2c_adapter *adapter, int address,
                int kind)
 {
-       int company, verstep;
        struct i2c_client *client;
        struct lm85_data *data;
        int err = 0;
@@ -1117,10 +1116,6 @@ static int lm85_detect(struct i2c_adapter *adapter, int address,
                goto ERROR0;
        }
 
-       /* OK. For now, we presume we have a valid client. We now create the
-          client structure, even though we cannot fill it completely yet.
-          But it allows us to access lm85_{read,write}_value. */
-
        if (!(data = kzalloc(sizeof(struct lm85_data), GFP_KERNEL))) {
                err = -ENOMEM;
                goto ERROR0;
@@ -1132,75 +1127,57 @@ static int lm85_detect(struct i2c_adapter *adapter, int address,
        client->adapter = adapter;
        client->driver = &lm85_driver;
 
-       /* Now, we do the remaining detection. */
-
-       company = lm85_read_value(client, LM85_REG_COMPANY);
-       verstep = lm85_read_value(client, LM85_REG_VERSTEP);
-
-       dev_dbg(&adapter->dev, "Detecting device at %d,0x%02x with"
-               " COMPANY: 0x%02x and VERSTEP: 0x%02x\n",
-               i2c_adapter_id(client->adapter), client->addr,
-               company, verstep);
-
-       /* If auto-detecting, Determine the chip type. */
-       if (kind <= 0) {
-               dev_dbg(&adapter->dev, "Autodetecting device at %d,0x%02x ...\n",
-                       i2c_adapter_id(adapter), address);
-               if (company == LM85_COMPANY_NATIONAL
-                   && verstep == LM85_VERSTEP_LM85C) {
-                       kind = lm85c;
-               } else if (company == LM85_COMPANY_NATIONAL
-                   && verstep == LM85_VERSTEP_LM85B) {
-                       kind = lm85b;
-               } else if (company == LM85_COMPANY_NATIONAL
-                   && (verstep & LM85_VERSTEP_VMASK) == LM85_VERSTEP_GENERIC) {
-                       dev_err(&adapter->dev, "Unrecognized version/stepping 0x%02x"
-                               " Defaulting to LM85.\n", verstep);
-                       kind = any_chip;
-               } else if (company == LM85_COMPANY_ANALOG_DEV
-                   && verstep == LM85_VERSTEP_ADM1027) {
-                       kind = adm1027;
-               } else if (company == LM85_COMPANY_ANALOG_DEV
-                   && (verstep == LM85_VERSTEP_ADT7463
-                        || verstep == LM85_VERSTEP_ADT7463C)) {
-                       kind = adt7463;
-               } else if (company == LM85_COMPANY_ANALOG_DEV
-                   && (verstep & LM85_VERSTEP_VMASK) == LM85_VERSTEP_GENERIC) {
-                       dev_err(&adapter->dev, "Unrecognized version/stepping 0x%02x"
-                               " Defaulting to Generic LM85.\n", verstep);
-                       kind = any_chip;
-               } else if (company == LM85_COMPANY_SMSC
-                   && (verstep == LM85_VERSTEP_EMC6D100_A0
-                        || verstep == LM85_VERSTEP_EMC6D100_A1)) {
-                       /* Unfortunately, we can't tell a '100 from a '101
-                        * from the registers.  Since a '101 is a '100
-                        * in a package with fewer pins and therefore no
-                        * 3.3V, 1.5V or 1.8V inputs, perhaps if those
-                        * inputs read 0, then it's a '101.
-                        */
-                       kind = emc6d100;
-               } else if (company == LM85_COMPANY_SMSC
-                   && verstep == LM85_VERSTEP_EMC6D102) {
-                       kind = emc6d102;
-               } else if (company == LM85_COMPANY_SMSC
-                   && (verstep & LM85_VERSTEP_VMASK) == LM85_VERSTEP_GENERIC) {
-                       dev_err(&adapter->dev, "lm85: Detected SMSC chip\n");
-                       dev_err(&adapter->dev, "lm85: Unrecognized version/stepping 0x%02x"
-                           " Defaulting to Generic LM85.\n", verstep);
-                       kind = any_chip;
-               } else if (kind == any_chip
-                   && (verstep & LM85_VERSTEP_VMASK) == LM85_VERSTEP_GENERIC) {
-                       dev_err(&adapter->dev, "Generic LM85 Version 6 detected\n");
-                       /* Leave kind as "any_chip" */
-               } else {
-                       dev_dbg(&adapter->dev, "Autodetection failed\n");
-                       /* Not an LM85... */
-                       if (kind == any_chip) {  /* User used force=x,y */
-                               dev_err(&adapter->dev, "Generic LM85 Version 6 not"
-                                       " found at %d,0x%02x. Try force_lm85c.\n",
-                                       i2c_adapter_id(adapter), address);
+       /* If auto-detecting, determine the chip type */
+       if (kind < 0) {
+               int company = lm85_read_value(client, LM85_REG_COMPANY);
+               int verstep = lm85_read_value(client, LM85_REG_VERSTEP);
+
+               dev_dbg(&adapter->dev, "Detecting device at 0x%02x with "
+                       "COMPANY: 0x%02x and VERSTEP: 0x%02x\n",
+                       address, company, verstep);
+
+               /* All supported chips have the version in common */
+               if ((verstep & LM85_VERSTEP_VMASK) != LM85_VERSTEP_GENERIC) {
+                       dev_dbg(&adapter->dev, "Autodetection failed: "
+                               "unsupported version\n");
+                       goto ERROR1;
+               }
+               kind = any_chip;
+
+               /* Now, refine the detection */
+               if (company == LM85_COMPANY_NATIONAL) {
+                       switch (verstep) {
+                       case LM85_VERSTEP_LM85C:
+                               kind = lm85c;
+                               break;
+                       case LM85_VERSTEP_LM85B:
+                               kind = lm85b;
+                               break;
+                       }
+               } else if (company == LM85_COMPANY_ANALOG_DEV) {
+                       switch (verstep) {
+                       case LM85_VERSTEP_ADM1027:
+                               kind = adm1027;
+                               break;
+                       case LM85_VERSTEP_ADT7463:
+                       case LM85_VERSTEP_ADT7463C:
+                               kind = adt7463;
+                               break;
                        }
-                       err = 0;
+               } else if (company == LM85_COMPANY_SMSC) {
+                       switch (verstep) {
+                       case LM85_VERSTEP_EMC6D100_A0:
+                       case LM85_VERSTEP_EMC6D100_A1:
+                               /* Note: we can't tell a '100 from a '101 */
+                               kind = emc6d100;
+                               break;
+                       case LM85_VERSTEP_EMC6D102:
+                               kind = emc6d102;
+                               break;
+                       }
+               } else {
+                       dev_dbg(&adapter->dev, "Autodetection failed: "
+                               "unknown vendor\n");
                        goto ERROR1;
                }
        }