1 files changed, 41 insertions, 5 deletions

diff --git a/drivers/hwmon/sch5627.c b/drivers/hwmon/sch5627.c
index 9a51dcca9b0d..020c87273ea1 100644
--- a/drivers/hwmon/sch5627.c
+++ b/drivers/hwmon/sch5627.c
@@ -52,6 +52,9 @@
 #define SCH5627_COMPANY_ID              0x5c
 #define SCH5627_PRIMARY_ID              0xa0
 
+#define SCH5627_CMD_READ                0x02
+#define SCH5627_CMD_WRITE               0x03
+
 #define SCH5627_REG_BUILD_CODE          0x39
 #define SCH5627_REG_BUILD_ID            0x3a
 #define SCH5627_REG_HWMON_ID            0x3c
@@ -94,11 +97,13 @@ static const char * const SCH5627_IN_LABELS[SCH5627_NO_IN] = {
 struct sch5627_data {
         unsigned short addr;
         struct device *hwmon_dev;
+        u8 control;
         u8 temp_max[SCH5627_NO_TEMPS];
         u8 temp_crit[SCH5627_NO_TEMPS];
         u16 fan_min[SCH5627_NO_FANS];
 
         struct mutex update_lock;
+        unsigned long last_battery;     /* In jiffies */
         char valid;                     /* !=0 if following fields are valid */
         unsigned long last_updated;     /* In jiffies */
         u16 temp[SCH5627_NO_TEMPS];
@@ -140,7 +145,7 @@ static inline void superio_exit(int base)
         release_region(base, 2);
 }
 
-static int sch5627_read_virtual_reg(struct sch5627_data *data, u16 reg)
+static int sch5627_send_cmd(struct sch5627_data *data, u8 cmd, u16 reg, u8 v)
 {
         u8 val;
         int i;
@@ -163,10 +168,14 @@ static int sch5627_read_virtual_reg(struct sch5627_data *data, u16 reg)
         outb(0x80, data->addr + 3);
 
         /* Write Request Packet Header */
-        outb(0x02, data->addr + 4); /* Access Type: VREG read */
+        outb(cmd, data->addr + 4); /* VREG Access Type read:0x02 write:0x03 */
         outb(0x01, data->addr + 5); /* # of Entries: 1 Byte (8-bit) */
         outb(0x04, data->addr + 2); /* Mailbox AP to first data entry loc. */
 
+        /* Write Value field */
+        if (cmd == SCH5627_CMD_WRITE)
+                outb(v, data->addr + 4);
+
         /* Write Address field */
         outb(reg & 0xff, data->addr + 6);
         outb(reg >> 8, data->addr + 7);
@@ -224,8 +233,22 @@ static int sch5627_read_virtual_reg(struct sch5627_data *data, u16 reg)
          * But if we do that things don't work, so let's not.
          */
 
-        /* Read Data from Mailbox */
-        return inb(data->addr + 4);
+        /* Read Value field */
+        if (cmd == SCH5627_CMD_READ)
+                return inb(data->addr + 4);
+
+        return 0;
+}
+
+static int sch5627_read_virtual_reg(struct sch5627_data *data, u16 reg)
+{
+        return sch5627_send_cmd(data, SCH5627_CMD_READ, reg, 0);
+}
+
+static int sch5627_write_virtual_reg(struct sch5627_data *data,
+                                     u16 reg, u8 val)
+{
+        return sch5627_send_cmd(data, SCH5627_CMD_WRITE, reg, val);
 }
 
 static int sch5627_read_virtual_reg16(struct sch5627_data *data, u16 reg)
@@ -272,6 +295,13 @@ static struct sch5627_data *sch5627_update_device(struct device *dev)
 
         mutex_lock(&data->update_lock);
 
+        /* Trigger a Vbat voltage measurement every 5 minutes */
+        if (time_after(jiffies, data->last_battery + 300 * HZ)) {
+                sch5627_write_virtual_reg(data, SCH5627_REG_CTRL,
+                                          data->control | 0x10);
+                data->last_battery = jiffies;
+        }
+
         /* Cache the values for 1 second */
         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
                 for (i = 0; i < SCH5627_NO_TEMPS; i++) {
@@ -696,11 +726,17 @@ static int __devinit sch5627_probe(struct platform_device *pdev)
                 err = val;
                 goto error;
         }
-        if (!(val & 0x01)) {
+        data->control = val;
+        if (!(data->control & 0x01)) {
                 pr_err("hardware monitoring not enabled\n");
                 err = -ENODEV;
                 goto error;
         }
+        /* Trigger a Vbat voltage measurement, so that we get a valid reading
+           the first time we read Vbat */
+        sch5627_write_virtual_reg(data, SCH5627_REG_CTRL,
+                                  data->control | 0x10);
+        data->last_battery = jiffies;
 
         /*
          * Read limits, we do this only once as reading a register on