platform/x86: thinkpad_acpi: check dytc version for lapmode sysfs

Lenovo platforms with DYTC versions earlier than version 5 don't set
the lapmode interface correctly, causing issues with thermald on
older platforms.

Add checking to only create the dytc_lapmode interface for version
5 and later.

Fixes: 1ac09656bded ("platform/x86: thinkpad_acpi: Add palm sensor support")
Signed-off-by: Mark Pearson <markpearson@lenovo.com>
Link: https://lore.kernel.org/r/20210311174843.3161-1-markpearson@lenovo.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index b881044..f7de90a 100644 (file)
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -9845,6 +9845,11 @@ static struct ibm_struct lcdshadow_driver_data = {
  * Thinkpad sensor interfaces
  */
 
+#define DYTC_CMD_QUERY        0 /* To get DYTC status - enable/revision */
+#define DYTC_QUERY_ENABLE_BIT 8  /* Bit        8 - 0 = disabled, 1 = enabled */
+#define DYTC_QUERY_SUBREV_BIT 16 /* Bits 16 - 27 - sub revision */
+#define DYTC_QUERY_REV_BIT    28 /* Bits 28 - 31 - revision */
+
 #define DYTC_CMD_GET          2 /* To get current IC function and mode */
 #define DYTC_GET_LAPMODE_BIT 17 /* Set when in lapmode */
 
@@ -9855,6 +9860,7 @@ static bool has_palmsensor;
 static bool has_lapsensor;
 static bool palm_state;
 static bool lap_state;
+static int dytc_version;
 
 static int dytc_command(int command, int *output)
 {
@@ -9869,6 +9875,33 @@ static int dytc_command(int command, int *output)
        return 0;
 }
 
+static int dytc_get_version(void)
+{
+       int err, output;
+
+       /* Check if we've been called before - and just return cached value */
+       if (dytc_version)
+               return dytc_version;
+
+       /* Otherwise query DYTC and extract version information */
+       err = dytc_command(DYTC_CMD_QUERY, &output);
+       /*
+        * If support isn't available (ENODEV) then don't return an error
+        * and don't create the sysfs group
+        */
+       if (err == -ENODEV)
+               return 0;
+       /* For all other errors we can flag the failure */
+       if (err)
+               return err;
+
+       /* Check DYTC is enabled and supports mode setting */
+       if (output & BIT(DYTC_QUERY_ENABLE_BIT))
+               dytc_version = (output >> DYTC_QUERY_REV_BIT) & 0xF;
+
+       return 0;
+}
+
 static int lapsensor_get(bool *present, bool *state)
 {
        int output, err;
@@ -9974,7 +10007,18 @@ static int tpacpi_proxsensor_init(struct ibm_init_struct *iibm)
                if (err)
                        return err;
        }
-       if (has_lapsensor) {
+
+       /* Check if we know the DYTC version, if we don't then get it */
+       if (!dytc_version) {
+               err = dytc_get_version();
+               if (err)
+                       return err;
+       }
+       /*
+        * Platforms before DYTC version 5 claim to have a lap sensor, but it doesn't work, so we
+        * ignore them
+        */
+       if (has_lapsensor && (dytc_version >= 5)) {
                err = sysfs_create_file(&tpacpi_pdev->dev.kobj, &dev_attr_dytc_lapmode.attr);
                if (err)
                        return err;
@@ -9999,14 +10043,9 @@ static struct ibm_struct proxsensor_driver_data = {
  * DYTC Platform Profile interface
  */
 
-#define DYTC_CMD_QUERY        0 /* To get DYTC status - enable/revision */
 #define DYTC_CMD_SET          1 /* To enable/disable IC function mode */
 #define DYTC_CMD_RESET    0x1ff /* To reset back to default */
 
-#define DYTC_QUERY_ENABLE_BIT 8  /* Bit        8 - 0 = disabled, 1 = enabled */
-#define DYTC_QUERY_SUBREV_BIT 16 /* Bits 16 - 27 - sub revision */
-#define DYTC_QUERY_REV_BIT    28 /* Bits 28 - 31 - revision */
-
 #define DYTC_GET_FUNCTION_BIT 8  /* Bits  8-11 - function setting */
 #define DYTC_GET_MODE_BIT     12 /* Bits 12-15 - mode setting */
 
@@ -10211,28 +10250,28 @@ static int tpacpi_dytc_profile_init(struct ibm_init_struct *iibm)
        if (err)
                return err;
 
+       /* Check if we know the DYTC version, if we don't then get it */
+       if (!dytc_version) {
+               err = dytc_get_version();
+               if (err)
+                       return err;
+       }
        /* Check DYTC is enabled and supports mode setting */
-       if (output & BIT(DYTC_QUERY_ENABLE_BIT)) {
-               /* Only DYTC v5.0 and later has this feature. */
-               int dytc_version;
-
-               dytc_version = (output >> DYTC_QUERY_REV_BIT) & 0xF;
-               if (dytc_version >= 5) {
-                       dbg_printk(TPACPI_DBG_INIT,
-                                  "DYTC version %d: thermal mode available\n", dytc_version);
-                       /* Create platform_profile structure and register */
-                       err = platform_profile_register(&dytc_profile);
-                       /*
-                        * If for some reason platform_profiles aren't enabled
-                        * don't quit terminally.
-                        */
-                       if (err)
-                               return 0;
+       if (dytc_version >= 5) {
+               dbg_printk(TPACPI_DBG_INIT,
+                               "DYTC version %d: thermal mode available\n", dytc_version);
+               /* Create platform_profile structure and register */
+               err = platform_profile_register(&dytc_profile);
+               /*
+                * If for some reason platform_profiles aren't enabled
+                * don't quit terminally.
+                */
+               if (err)
+                       return 0;
 
-                       dytc_profile_available = true;
-                       /* Ensure initial values are correct */
-                       dytc_profile_refresh();
-               }
+               dytc_profile_available = true;
+               /* Ensure initial values are correct */
+               dytc_profile_refresh();
        }
        return 0;
 }