hwmon: (lm90) Support MAX6646, MAX6647 and MAX6649

These Maxim chips are similar to MAX6657 but use unsigned temperature
values to allow for readings up to 145 degrees.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

3 files changed, 82 insertions, 13 deletions

diff --git a/Documentation/hwmon/lm90 b/Documentation/hwmon/lm90
index 53cd829f3f4d..e0d5206d1de3 100644
--- a/Documentation/hwmon/lm90
+++ b/Documentation/hwmon/lm90
@@ -32,6 +32,21 @@ Supported chips:
     Addresses scanned: I2C 0x4c and 0x4d
     Datasheet: Publicly available at the ON Semiconductor website
                http://www.onsemi.com/PowerSolutions/product.do?id=ADT7461
+  * Maxim MAX6646
+    Prefix: 'max6646'
+    Addresses scanned: I2C 0x4d
+    Datasheet: Publicly available at the Maxim website
+               http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3497
+  * Maxim MAX6647
+    Prefix: 'max6646'
+    Addresses scanned: I2C 0x4e
+    Datasheet: Publicly available at the Maxim website
+               http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3497
+  * Maxim MAX6649
+    Prefix: 'max6646'
+    Addresses scanned: I2C 0x4c
+    Datasheet: Publicly available at the Maxim website
+               http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3497
   * Maxim MAX6657
     Prefix: 'max6657'
     Addresses scanned: I2C 0x4c
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 96701e099e81..6de1e0ffd391 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -511,7 +511,8 @@ config SENSORS_LM90
         help
           If you say yes here you get support for National Semiconductor LM90,
           LM86, LM89 and LM99, Analog Devices ADM1032 and ADT7461, and Maxim
-          MAX6657, MAX6658, MAX6659, MAX6680 and MAX6681 sensor chips.
+          MAX6646, MAX6647, MAX6649, MAX6657, MAX6658, MAX6659, MAX6680 and
+          MAX6681 sensor chips.
 
           This driver can also be built as a module.  If so, the module
           will be called lm90.
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index 85ba2c4feb46..fe09f82c42e8 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -32,6 +32,11 @@
  * supported by this driver. These chips lack the remote temperature
  * offset feature.
  *
+ * This driver also supports the MAX6646, MAX6647 and MAX6649 chips
+ * made by Maxim.  These are again similar to the LM86, but they use
+ * unsigned temperature values and can report temperatures from 0 to
+ * 145 degrees.
+ *
  * This driver also supports the MAX6680 and MAX6681, two other sensor
  * chips made by Maxim. These are quite similar to the other Maxim
  * chips. The MAX6680 and MAX6681 only differ in the pinout so they can
@@ -76,9 +81,10 @@
  * Addresses to scan
  * Address is fully defined internally and cannot be changed except for
  * MAX6659, MAX6680 and MAX6681.
- * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, MAX6657 and MAX6658
- * have address 0x4c.
- * ADM1032-2, ADT7461-2, LM89-1, and LM99-1 have address 0x4d.
+ * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, MAX6649, MAX6657
+ * and MAX6658 have address 0x4c.
+ * ADM1032-2, ADT7461-2, LM89-1, LM99-1 and MAX6646 have address 0x4d.
+ * MAX6647 has address 0x4e.
  * MAX6659 can have address 0x4c, 0x4d or 0x4e (unsupported).
  * MAX6680 and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
  * 0x4c, 0x4d or 0x4e.
@@ -91,7 +97,8 @@ static const unsigned short normal_i2c[] = {
  * Insmod parameters
  */
 
-I2C_CLIENT_INSMOD_7(lm90, adm1032, lm99, lm86, max6657, adt7461, max6680);
+I2C_CLIENT_INSMOD_8(lm90, adm1032, lm99, lm86, max6657, adt7461, max6680,
+                    max6646);
 
 /*
  * The LM90 registers
@@ -132,7 +139,7 @@ I2C_CLIENT_INSMOD_7(lm90, adm1032, lm99, lm86, max6657, adt7461, max6680);
 #define LM90_REG_R_TCRIT_HYST           0x21
 #define LM90_REG_W_TCRIT_HYST           0x21
 
-/* MAX6657-specific registers */
+/* MAX6646/6647/6649/6657/6658/6659 registers */
 
 #define MAX6657_REG_R_LOCAL_TEMPL       0x11
 
@@ -164,6 +171,9 @@ static const struct i2c_device_id lm90_id[] = {
         { "lm86", lm86 },
         { "lm89", lm99 },
         { "lm99", lm99 },       /* Missing temperature offset */
+        { "max6646", max6646 },
+        { "max6647", max6646 },
+        { "max6649", max6646 },
         { "max6657", max6657 },
         { "max6658", max6657 },
         { "max6659", max6657 },
@@ -205,7 +215,7 @@ struct lm90_data {
         s16 temp11[5];  /* 0: remote input
                            1: remote low limit
                            2: remote high limit
-                           3: remote offset (except max6657)
+                           3: remote offset (except max6646 and max6657)
                            4: local input */
         u8 temp_hyst;
         u8 alarms; /* bitvector */
@@ -216,7 +226,8 @@ struct lm90_data {
  * For local temperatures and limits, critical limits and the hysteresis
  * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
  * For remote temperatures and limits, it uses signed 11-bit values with
- * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.
+ * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.  Some
+ * Maxim chips use unsigned values.
  */
 
 static inline int temp_from_s8(s8 val)
@@ -224,11 +235,21 @@ static inline int temp_from_s8(s8 val)
         return val * 1000;
 }
 
+static inline int temp_from_u8(u8 val)
+{
+        return val * 1000;
+}
+
 static inline int temp_from_s16(s16 val)
 {
         return val / 32 * 125;
 }
 
+static inline int temp_from_u16(u16 val)
+{
+        return val / 32 * 125;
+}
+
 static s8 temp_to_s8(long val)
 {
         if (val <= -128000)
@@ -240,6 +261,15 @@ static s8 temp_to_s8(long val)
         return (val + 500) / 1000;
 }
 
+static u8 temp_to_u8(long val)
+{
+        if (val <= 0)
+                return 0;
+        if (val >= 255000)
+                return 255;
+        return (val + 500) / 1000;
+}
+
 static s16 temp_to_s16(long val)
 {
         if (val <= -128000)
@@ -331,6 +361,8 @@ static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
 
         if (data->kind == adt7461)
                 temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
+        else if (data->kind == max6646)
+                temp = temp_from_u8(data->temp8[attr->index]);
         else
                 temp = temp_from_s8(data->temp8[attr->index]);
 
@@ -356,6 +388,8 @@ static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
         mutex_lock(&data->update_lock);
         if (data->kind == adt7461)
                 data->temp8[nr] = temp_to_u8_adt7461(data, val);
+        else if (data->kind == max6646)
+                data->temp8[nr] = temp_to_u8(val);
         else
                 data->temp8[nr] = temp_to_s8(val);
         i2c_smbus_write_byte_data(client, reg[nr], data->temp8[nr]);
@@ -372,6 +406,8 @@ static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
 
         if (data->kind == adt7461)
                 temp = temp_from_u16_adt7461(data, data->temp11[attr->index]);
+        else if (data->kind == max6646)
+                temp = temp_from_u16(data->temp11[attr->index]);
         else
                 temp = temp_from_s16(data->temp11[attr->index]);
 
@@ -401,12 +437,15 @@ static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
                 data->temp11[nr] = temp_to_u16_adt7461(data, val);
         else if (data->kind == max6657 || data->kind == max6680)
                 data->temp11[nr] = temp_to_s8(val) << 8;
+        else if (data->kind == max6646)
+                data->temp11[nr] = temp_to_u8(val) << 8;
         else
                 data->temp11[nr] = temp_to_s16(val);
 
         i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2],
                                   data->temp11[nr] >> 8);
-        if (data->kind != max6657 && data->kind != max6680)
+        if (data->kind != max6657 && data->kind != max6680
+            && data->kind != max6646)
                 i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
                                           data->temp11[nr] & 0xff);
         mutex_unlock(&data->update_lock);
@@ -689,6 +728,16 @@ static int lm90_detect(struct i2c_client *new_client, int kind,
                          && (reg_config1 & 0x03) == 0x00
                          && reg_convrate <= 0x07) {
                                 kind = 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) {
+                                kind = max6646;
                         }
                 }
 
@@ -719,6 +768,8 @@ static int lm90_detect(struct i2c_client *new_client, int kind,
                 name = "max6680";
         } else if (kind == adt7461) {
                 name = "adt7461";
+        } else if (kind == max6646) {
+                name = "max6646";
         }
         strlcpy(info->type, name, I2C_NAME_SIZE);
 
@@ -758,7 +809,7 @@ static int lm90_probe(struct i2c_client *new_client,
                                               &dev_attr_pec)))
                         goto exit_remove_files;
         }
-        if (data->kind != max6657) {
+        if (data->kind != max6657 && data->kind != max6646) {
                 if ((err = device_create_file(&new_client->dev,
                                 &sensor_dev_attr_temp2_offset.dev_attr)))
                         goto exit_remove_files;
@@ -824,7 +875,7 @@ static int lm90_remove(struct i2c_client *client)
         hwmon_device_unregister(data->hwmon_dev);
         sysfs_remove_group(&client->dev.kobj, &lm90_group);
         device_remove_file(&client->dev, &dev_attr_pec);
-        if (data->kind != max6657)
+        if (data->kind != max6657 && data->kind != max6646)
                 device_remove_file(&client->dev,
                                    &sensor_dev_attr_temp2_offset.dev_attr);
 
@@ -881,7 +932,7 @@ static struct lm90_data *lm90_update_device(struct device *dev)
                 lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[3]);
                 lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);
 
-                if (data->kind == max6657) {
+                if (data->kind == max6657 || data->kind == max6646) {
                         lm90_read16(client, LM90_REG_R_LOCAL_TEMP,
                                     MAX6657_REG_R_LOCAL_TEMPL,
                                     &data->temp11[4]);
@@ -896,6 +947,7 @@ static struct lm90_data *lm90_update_device(struct device *dev)
                 if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h) == 0) {
                         data->temp11[1] = h << 8;
                         if (data->kind != max6657 && data->kind != max6680
+                         && data->kind != max6646
                          && lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL,
                                           &l) == 0)
                                 data->temp11[1] |= l;
@@ -903,12 +955,13 @@ static struct lm90_data *lm90_update_device(struct device *dev)
                 if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h) == 0) {
                         data->temp11[2] = h << 8;
                         if (data->kind != max6657 && data->kind != max6680
+                         && data->kind != max6646
                          && lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL,
                                           &l) == 0)
                                 data->temp11[2] |= l;
                 }
 
-                if (data->kind != max6657) {
+                if (data->kind != max6657 && data->kind != max6646) {
                         if (lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSH,
                                           &h) == 0
                          && lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSL,