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>

1 files changed, 50 insertions, 73 deletions

diff --git a/drivers/hwmon/lm85.c b/drivers/hwmon/lm85.c
index 12d446f54f97..3594a02f281b 100644
--- 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;
                 }
         }