hwmon: (lm90) Clean up detect function

As kind is now hard-coded to -1, there is room for code clean-ups.

Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 96 insertions, 132 deletions

diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index 1aff7575799d..b7c905f50ed4 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -1,7 +1,7 @@
 /*
  * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
  *          monitoring
- * Copyright (C) 2003-2008  Jean Delvare <khali@linux-fr.org>
+ * Copyright (C) 2003-2009  Jean Delvare <khali@linux-fr.org>
  *
  * Based on the lm83 driver. The LM90 is a sensor chip made by National
  * Semiconductor. It reports up to two temperatures (its own plus up to
@@ -661,154 +661,118 @@ static int lm90_detect(struct i2c_client *new_client, int kind,
 {
         struct i2c_adapter *adapter = new_client->adapter;
         int address = new_client->addr;
-        const char *name = "";
+        const char *name = NULL;
+        int man_id, chip_id, reg_config1, reg_convrate;
 
         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                 return -ENODEV;
 
-        /*
-         * Now we do the remaining detection. A negative kind means that
-         * the driver was loaded with no force parameter (default), so we
-         * must both detect and identify the chip. A zero kind means that
-         * the driver was loaded with the force parameter, the detection
-         * step shall be skipped. A positive kind means that the driver
-         * was loaded with the force parameter and a given kind of chip is
-         * requested, so both the detection and the identification steps
-         * are skipped.
-         */
-
-        /* Default to an LM90 if forced */
-        if (kind == 0)
-                kind = lm90;
-
-        if (kind < 0) { /* detection and identification */
-                int man_id, chip_id, reg_config1, reg_convrate;
-
-                if ((man_id = i2c_smbus_read_byte_data(new_client,
+        /* detection and identification */
+        if ((man_id = i2c_smbus_read_byte_data(new_client,
                                                 LM90_REG_R_MAN_ID)) < 0
-                 || (chip_id = i2c_smbus_read_byte_data(new_client,
+         || (chip_id = i2c_smbus_read_byte_data(new_client,
                                                 LM90_REG_R_CHIP_ID)) < 0
-                 || (reg_config1 = i2c_smbus_read_byte_data(new_client,
+         || (reg_config1 = i2c_smbus_read_byte_data(new_client,
                                                 LM90_REG_R_CONFIG1)) < 0
-                 || (reg_convrate = i2c_smbus_read_byte_data(new_client,
+         || (reg_convrate = i2c_smbus_read_byte_data(new_client,
                                                 LM90_REG_R_CONVRATE)) < 0)
+                return -ENODEV;
+
+        if ((address == 0x4C || address == 0x4D)
+         && man_id == 0x01) { /* National Semiconductor */
+                int reg_config2;
+
+                reg_config2 = i2c_smbus_read_byte_data(new_client,
+                                                LM90_REG_R_CONFIG2);
+                if (reg_config2 < 0)
                         return -ENODEV;
-                
-                if ((address == 0x4C || address == 0x4D)
-                 && man_id == 0x01) { /* National Semiconductor */
-                        int reg_config2;
-
-                        if ((reg_config2 = i2c_smbus_read_byte_data(new_client,
-                                                LM90_REG_R_CONFIG2)) < 0)
-                                return -ENODEV;
-
-                        if ((reg_config1 & 0x2A) == 0x00
-                         && (reg_config2 & 0xF8) == 0x00
-                         && reg_convrate <= 0x09) {
-                                if (address == 0x4C
-                                 && (chip_id & 0xF0) == 0x20) { /* LM90 */
-                                        kind = lm90;
-                                } else
-                                if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
-                                        kind = lm99;
-                                        dev_info(&adapter->dev,
-                                                 "Assuming LM99 chip at "
-                                                 "0x%02x\n", address);
-                                        dev_info(&adapter->dev,
-                                                 "If it is an LM89, pass "
-                                                 "force_lm86=%d,0x%02x when "
-                                                 "loading the lm90 driver\n",
-                                                 i2c_adapter_id(adapter),
-                                                 address);
-                                } else
-                                if (address == 0x4C
-                                 && (chip_id & 0xF0) == 0x10) { /* LM86 */
-                                        kind = lm86;
-                                }
-                        }
-                } else
-                if ((address == 0x4C || address == 0x4D)
-                 && man_id == 0x41) { /* Analog Devices */
-                        if ((chip_id & 0xF0) == 0x40 /* ADM1032 */
-                         && (reg_config1 & 0x3F) == 0x00
-                         && reg_convrate <= 0x0A) {
-                                kind = adm1032;
-                        } else
-                        if (chip_id == 0x51 /* ADT7461 */
-                         && (reg_config1 & 0x1B) == 0x00
-                         && reg_convrate <= 0x0A) {
-                                kind = adt7461;
-                        }
-                } else
-                if (man_id == 0x4D) { /* Maxim */
-                        /*
-                         * The MAX6657, MAX6658 and MAX6659 do NOT have a
-                         * chip_id register. Reading from that address will
-                         * return the last read value, which in our case is
-                         * those of the man_id register. Likewise, the config1
-                         * register seems to lack a low nibble, so the value
-                         * will be those of the previous read, so in our case
-                         * those of the man_id register.
-                         */
-                        if (chip_id == man_id
-                         && (address == 0x4C || address == 0x4D)
-                         && (reg_config1 & 0x1F) == (man_id & 0x0F)
-                         && reg_convrate <= 0x09) {
-                                kind = max6657;
+
+                if ((reg_config1 & 0x2A) == 0x00
+                 && (reg_config2 & 0xF8) == 0x00
+                 && reg_convrate <= 0x09) {
+                        if (address == 0x4C
+                         && (chip_id & 0xF0) == 0x20) { /* LM90 */
+                                name = "lm90";
                         } else
-                        /* The chip_id register of the MAX6680 and MAX6681
-                         * holds the revision of the chip.
-                         * the lowest bit of the config1 register is unused
-                         * and should return zero when read, so should the
-                         * second to last bit of config1 (software reset)
-                         */
-                        if (chip_id == 0x01
-                         && (reg_config1 & 0x03) == 0x00
-                         && reg_convrate <= 0x07) {
-                                kind = max6680;
+                        if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
+                                name = "lm99";
+                                dev_info(&adapter->dev,
+                                         "Assuming LM99 chip at 0x%02x\n",
+                                         address);
+                                dev_info(&adapter->dev,
+                                         "If it is an LM89, instantiate it "
+                                         "with the new_device sysfs "
+                                         "interface\n");
                         } else
-                        /* The chip_id register of the MAX6646/6647/6649
-                         * holds the revision of the chip.
-                         * The lowest 6 bits of the config1 register are
-                         * unused and should return zero when read.
-                         */
-                        if (chip_id == 0x59
-                         && (reg_config1 & 0x3f) == 0x00
-                         && reg_convrate <= 0x07) {
-                                kind = max6646;
+                        if (address == 0x4C
+                         && (chip_id & 0xF0) == 0x10) { /* LM86 */
+                                name = "lm86";
                         }
                 }
-
-                if (kind <= 0) { /* identification failed */
-                        dev_dbg(&adapter->dev,
-                                "Unsupported chip at 0x%02x (man_id=0x%02X, "
-                                "chip_id=0x%02X)\n", address, man_id, chip_id);
-                        return -ENODEV;
+        } else
+        if ((address == 0x4C || address == 0x4D)
+         && man_id == 0x41) { /* Analog Devices */
+                if ((chip_id & 0xF0) == 0x40 /* ADM1032 */
+                 && (reg_config1 & 0x3F) == 0x00
+                 && reg_convrate <= 0x0A) {
+                        name = "adm1032";
+                        /* The ADM1032 supports PEC, but only if combined
+                           transactions are not used. */
+                        if (i2c_check_functionality(adapter,
+                                                    I2C_FUNC_SMBUS_BYTE))
+                                info->flags |= I2C_CLIENT_PEC;
+                } else
+                if (chip_id == 0x51 /* ADT7461 */
+                 && (reg_config1 & 0x1B) == 0x00
+                 && reg_convrate <= 0x0A) {
+                        name = "adt7461";
+                }
+        } else
+        if (man_id == 0x4D) { /* Maxim */
+                /*
+                 * The MAX6657, MAX6658 and MAX6659 do NOT have a chip_id
+                 * register. Reading from that address will return the last
+                 * read value, which in our case is those of the man_id
+                 * register. Likewise, the config1 register seems to lack a
+                 * low nibble, so the value will be those of the previous
+                 * read, so in our case those of the man_id register.
+                 */
+                if (chip_id == man_id
+                 && (address == 0x4C || address == 0x4D)
+                 && (reg_config1 & 0x1F) == (man_id & 0x0F)
+                 && reg_convrate <= 0x09) {
+                        name = "max6657";
+                } else
+                /*
+                 * The chip_id register of the MAX6680 and MAX6681 holds the
+                 * revision of the chip. The lowest bit of the config1 register
+                 * is unused and should return zero when read, so should the
+                 * second to last bit of config1 (software reset).
+                 */
+                if (chip_id == 0x01
+                 && (reg_config1 & 0x03) == 0x00
+                 && reg_convrate <= 0x07) {
+                        name = "max6680";
+                } else
+                /*
+                 * The chip_id register of the MAX6646/6647/6649 holds the
+                 * revision of the chip. The lowest 6 bits of the config1
+                 * register are unused and should return zero when read.
+                 */
+                if (chip_id == 0x59
+                 && (reg_config1 & 0x3f) == 0x00
+                 && reg_convrate <= 0x07) {
+                        name = "max6646";
                 }
         }
 
-        /* Fill the i2c board info */
-        if (kind == lm90) {
-                name = "lm90";
-        } else if (kind == adm1032) {
-                name = "adm1032";
-                /* The ADM1032 supports PEC, but only if combined
-                   transactions are not used. */
-                if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
-                        info->flags |= I2C_CLIENT_PEC;
-        } else if (kind == lm99) {
-                name = "lm99";
-        } else if (kind == lm86) {
-                name = "lm86";
-        } else if (kind == max6657) {
-                name = "max6657";
-        } else if (kind == max6680) {
-                name = "max6680";
-        } else if (kind == adt7461) {
-                name = "adt7461";
-        } else if (kind == max6646) {
-                name = "max6646";
+        if (!name) { /* identification failed */
+                dev_dbg(&adapter->dev,
+                        "Unsupported chip at 0x%02x (man_id=0x%02X, "
+                        "chip_id=0x%02X)\n", address, man_id, chip_id);
+                return -ENODEV;
         }
+
         strlcpy(info->type, name, I2C_NAME_SIZE);
 
         return 0;