hwmon: (smsc47m1) Differentiate between LPC47M233 and LPC47M292

The SMSC LPC47M233 and LPC47M292 chips have the same device ID but
are not compatible.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Juerg Haefliger <juergh@gmail.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/hwmon/smsc47m1.c b/drivers/hwmon/smsc47m1.c
index a92dbb97ee99..ba75bfcf14ce 100644
--- a/drivers/hwmon/smsc47m1.c
+++ b/drivers/hwmon/smsc47m1.c
@@ -86,6 +86,7 @@ superio_exit(void)
 #define SUPERIO_REG_ACT         0x30
 #define SUPERIO_REG_BASE        0x60
 #define SUPERIO_REG_DEVID       0x20
+#define SUPERIO_REG_DEVREV      0x21
 
 /* Logical device registers */
 
@@ -429,6 +430,9 @@ static int __init smsc47m1_find(unsigned short *addr,
          * The LPC47M292 (device id 0x6B) is somewhat compatible, but it
          * supports a 3rd fan, and the pin configuration registers are
          * unfortunately different.
+         * The LPC47M233 has the same device id (0x6B) but is not compatible.
+         * We check the high bit of the device revision register to
+         * differentiate them.
          */
         switch (val) {
         case 0x51:
@@ -448,6 +452,13 @@ static int __init smsc47m1_find(unsigned short *addr,
                 sio_data->type = smsc47m1;
                 break;
         case 0x6B:
+                if (superio_inb(SUPERIO_REG_DEVREV) & 0x80) {
+                        pr_debug(DRVNAME ": "
+                                 "Found SMSC LPC47M233, unsupported\n");
+                        superio_exit();
+                        return -ENODEV;
+                }
+
                 pr_info(DRVNAME ": Found SMSC LPC47M292\n");
                 sio_data->type = smsc47m2;
                 break;