hwmon: (lm90) Add support for extra features of max6659

Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 59 insertions, 6 deletions

diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index 68ee8f78843e..de544817d673 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -28,9 +28,11 @@
  * This driver also supports the MAX6657, MAX6658 and MAX6659 sensor
  * chips made by Maxim. These chips are similar to the LM86.
  * Note that there is no easy way to differentiate between the three
- * variants. The extra address and features of the MAX6659 are not
- * supported by this driver. These chips lack the remote temperature
- * offset feature.
+ * variants. We use the device address to detect MAX6659, which will result
+ * in a detection as max6657 if it is on address 0x4c. The extra address
+ * and features of the MAX6659 are only supported if the chip is configured
+ * explicitly as max6659, or if its address is not 0x4c.
+ * These chips lack the remote temperature offset feature.
  *
  * This driver also supports the MAX6646, MAX6647, MAX6648, MAX6649 and
  * MAX6692 chips made by Maxim.  These are again similar to the LM86,
@@ -138,6 +140,10 @@ enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
 /* MAX6646/6647/6649/6657/6658/6659 registers */
 
 #define MAX6657_REG_R_LOCAL_TEMPL       0x11
+#define MAX6659_REG_R_REMOTE_EMERG      0x16
+#define MAX6659_REG_W_REMOTE_EMERG      0x16
+#define MAX6659_REG_R_LOCAL_EMERG       0x17
+#define MAX6659_REG_W_LOCAL_EMERG       0x17
 
 /*
  * Device flags
@@ -147,6 +153,7 @@ enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
 #define LM90_HAVE_OFFSET        (1 << 1) /* temperature offset register */
 #define LM90_HAVE_LOCAL_EXT     (1 << 2) /* extended local temperature  */
 #define LM90_HAVE_REM_LIMIT_EXT (1 << 3) /* extended remote limit       */
+#define LM90_HAVE_EMERGENCY     (1 << 4) /* 3rd upper (emergency) limit */
 
 /*
  * Functions declaration
@@ -213,10 +220,12 @@ struct lm90_data {
         u8 alert_alarms;        /* Which alarm bits trigger ALERT# */
 
         /* registers values */
-        s8 temp8[4];    /* 0: local low limit
+        s8 temp8[6];    /* 0: local low limit
                            1: local high limit
                            2: local critical limit
-                           3: remote critical limit */
+                           3: remote critical limit
+                           4: local emergency limit (max6659 only)
+                           5: remote emergency limit (max6659 only) */
         s16 temp11[5];  /* 0: remote input
                            1: remote low limit
                            2: remote high limit
@@ -381,11 +390,13 @@ static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
 static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
                          const char *buf, size_t count)
 {
-        static const u8 reg[4] = {
+        static const u8 reg[6] = {
                 LM90_REG_W_LOCAL_LOW,
                 LM90_REG_W_LOCAL_HIGH,
                 LM90_REG_W_LOCAL_CRIT,
                 LM90_REG_W_REMOTE_CRIT,
+                MAX6659_REG_W_LOCAL_EMERG,
+                MAX6659_REG_W_REMOTE_EMERG,
         };
 
         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
@@ -608,6 +619,30 @@ static const struct attribute_group lm90_group = {
         .attrs = lm90_attributes,
 };
 
+/*
+ * Additional attributes for devices with emergency sensors
+ */
+static SENSOR_DEVICE_ATTR(temp1_emergency, S_IWUSR | S_IRUGO, show_temp8,
+        set_temp8, 4);
+static SENSOR_DEVICE_ATTR(temp2_emergency, S_IWUSR | S_IRUGO, show_temp8,
+        set_temp8, 5);
+static SENSOR_DEVICE_ATTR(temp1_emergency_hyst, S_IRUGO, show_temphyst,
+                          NULL, 4);
+static SENSOR_DEVICE_ATTR(temp2_emergency_hyst, S_IRUGO, show_temphyst,
+                          NULL, 5);
+
+static struct attribute *lm90_emergency_attributes[] = {
+        &sensor_dev_attr_temp1_emergency.dev_attr.attr,
+        &sensor_dev_attr_temp2_emergency.dev_attr.attr,
+        &sensor_dev_attr_temp1_emergency_hyst.dev_attr.attr,
+        &sensor_dev_attr_temp2_emergency_hyst.dev_attr.attr,
+        NULL
+};
+
+static const struct attribute_group lm90_emergency_group = {
+        .attrs = lm90_emergency_attributes,
+};
+
 /* pec used for ADM1032 only */
 static ssize_t show_pec(struct device *dev, struct device_attribute *dummy,
                         char *buf)
@@ -826,6 +861,9 @@ static int lm90_detect(struct i2c_client *new_client,
 
 static void lm90_remove_files(struct i2c_client *client, struct lm90_data *data)
 {
+        if (data->flags & LM90_HAVE_EMERGENCY)
+                sysfs_remove_group(&client->dev.kobj,
+                                   &lm90_emergency_group);
         if (data->flags & LM90_HAVE_OFFSET)
                 device_remove_file(&client->dev,
                                    &sensor_dev_attr_temp2_offset.dev_attr);
@@ -881,6 +919,9 @@ static int lm90_probe(struct i2c_client *new_client,
             && data->kind != max6646 && data->kind != max6680)
                 data->flags |= LM90_HAVE_REM_LIMIT_EXT;
 
+        if (data->kind == max6659)
+                data->flags |= LM90_HAVE_EMERGENCY;
+
         /* Initialize the LM90 chip */
         lm90_init_client(new_client);
 
@@ -899,6 +940,12 @@ static int lm90_probe(struct i2c_client *new_client,
                 if (err)
                         goto exit_remove_files;
         }
+        if (data->flags & LM90_HAVE_EMERGENCY) {
+                err = sysfs_create_group(&new_client->dev.kobj,
+                                         &lm90_emergency_group);
+                if (err)
+                        goto exit_remove_files;
+        }
 
         data->hwmon_dev = hwmon_device_register(&new_client->dev);
         if (IS_ERR(data->hwmon_dev)) {
@@ -1082,6 +1129,12 @@ static struct lm90_data *lm90_update_device(struct device *dev)
                                           &l) == 0)
                                 data->temp11[3] = (h << 8) | l;
                 }
+                if (data->flags & LM90_HAVE_EMERGENCY) {
+                        lm90_read_reg(client, MAX6659_REG_R_LOCAL_EMERG,
+                                      &data->temp8[4]);
+                        lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG,
+                                      &data->temp8[5]);
+                }
                 lm90_read_reg(client, LM90_REG_R_STATUS, &data->alarms);
 
                 /* Re-enable ALERT# output if it was originally enabled and