platform/x86: thinkpad_acpi: Simplify thermal mode checking

Add a thermal_read_mode_check helper to make the code
simpler during init. This helps particularly when the new
TPACPI_THERMAL_TPEC_12 mode is added in the next patch.

Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Vishnu Sankar <vishnuocv@gmail.com>
Link: https://lore.kernel.org/r/20240215134102.25118-1-vishnuocv@gmail.com
[ij: Reflowed the comment to 80 cols, multiline if braces, added __init.]
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 897d4cd9e5f4987df8d81ca68a2488e5d73200ab..9a49573ae3786abbfb457da48cb88e4f67d6c5db 100644 (file)
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -6149,6 +6149,78 @@ struct ibm_thermal_sensors_struct {
 static enum thermal_access_mode thermal_read_mode;
 static bool thermal_use_labels;
 
+/* Function to check thermal read mode */
+static enum thermal_access_mode __init thermal_read_mode_check(void)
+{
+       u8 t, ta1, ta2, ver = 0;
+       int i;
+       int acpi_tmp7;
+
+       acpi_tmp7 = acpi_evalf(ec_handle, NULL, "TMP7", "qv");
+
+       if (thinkpad_id.ec_model) {
+               /*
+                * Direct EC access mode: sensors at registers 0x78-0x7F,
+                * 0xC0-0xC7. Registers return 0x00 for non-implemented,
+                * thermal sensors return 0x80 when not available.
+                *
+                * In some special cases (when Power Supply ID is 0xC2)
+                * above rule causes thermal control issues. Offset 0xEF
+                * determines EC version. 0xC0-0xC7 are not thermal registers
+                * in Ver 3.
+                */
+               if (!acpi_ec_read(TP_EC_FUNCREV, &ver))
+                       pr_warn("Thinkpad ACPI EC unable to access EC version\n");
+
+               ta1 = ta2 = 0;
+               for (i = 0; i < 8; i++) {
+                       if (acpi_ec_read(TP_EC_THERMAL_TMP0 + i, &t)) {
+                               ta1 |= t;
+                       } else {
+                               ta1 = 0;
+                               break;
+                       }
+                       if (ver < 3) {
+                               if (acpi_ec_read(TP_EC_THERMAL_TMP8 + i, &t)) {
+                                       ta2 |= t;
+                               } else {
+                                       ta1 = 0;
+                                       break;
+                               }
+                       }
+               }
+
+               if (ta1 == 0) {
+                       /* This is sheer paranoia, but we handle it anyway */
+                       if (acpi_tmp7) {
+                               pr_err("ThinkPad ACPI EC access misbehaving, falling back to ACPI TMPx access mode\n");
+                               return TPACPI_THERMAL_ACPI_TMP07;
+                       }
+                       pr_err("ThinkPad ACPI EC access misbehaving, disabling thermal sensors access\n");
+                       return TPACPI_THERMAL_NONE;
+               }
+
+               if (ver >= 3) {
+                       thermal_use_labels = true;
+                       return TPACPI_THERMAL_TPEC_8;
+               }
+
+               return (ta2 != 0) ? TPACPI_THERMAL_TPEC_16 : TPACPI_THERMAL_TPEC_8;
+       }
+
+       if (acpi_tmp7) {
+               if (tpacpi_is_ibm() && acpi_evalf(ec_handle, NULL, "UPDT", "qv")) {
+                       /* 600e/x, 770e, 770x */
+                       return TPACPI_THERMAL_ACPI_UPDT;
+               }
+               /* IBM/LENOVO DSDT EC.TMPx access, max 8 sensors */
+               return TPACPI_THERMAL_ACPI_TMP07;
+       }
+
+       /* temperatures not supported on 570, G4x, R30, R31, R32 */
+       return TPACPI_THERMAL_NONE;
+}
+
 /* idx is zero-based */
 static int thermal_get_sensor(int idx, s32 *value)
 {
@@ -6375,78 +6447,9 @@ static const struct attribute_group temp_label_attr_group = {
 
 static int __init thermal_init(struct ibm_init_struct *iibm)
 {
-       u8 t, ta1, ta2, ver = 0;
-       int i;
-       int acpi_tmp7;
-
        vdbg_printk(TPACPI_DBG_INIT, "initializing thermal subdriver\n");
 
-       acpi_tmp7 = acpi_evalf(ec_handle, NULL, "TMP7", "qv");
-
-       if (thinkpad_id.ec_model) {
-               /*
-                * Direct EC access mode: sensors at registers
-                * 0x78-0x7F, 0xC0-0xC7.  Registers return 0x00 for
-                * non-implemented, thermal sensors return 0x80 when
-                * not available
-                * The above rule is unfortunately flawed. This has been seen with
-                * 0xC2 (power supply ID) causing thermal control problems.
-                * The EC version can be determined by offset 0xEF and at least for
-                * version 3 the Lenovo firmware team confirmed that registers 0xC0-0xC7
-                * are not thermal registers.
-                */
-               if (!acpi_ec_read(TP_EC_FUNCREV, &ver))
-                       pr_warn("Thinkpad ACPI EC unable to access EC version\n");
-
-               ta1 = ta2 = 0;
-               for (i = 0; i < 8; i++) {
-                       if (acpi_ec_read(TP_EC_THERMAL_TMP0 + i, &t)) {
-                               ta1 |= t;
-                       } else {
-                               ta1 = 0;
-                               break;
-                       }
-                       if (ver < 3) {
-                               if (acpi_ec_read(TP_EC_THERMAL_TMP8 + i, &t)) {
-                                       ta2 |= t;
-                               } else {
-                                       ta1 = 0;
-                                       break;
-                               }
-                       }
-               }
-               if (ta1 == 0) {
-                       /* This is sheer paranoia, but we handle it anyway */
-                       if (acpi_tmp7) {
-                               pr_err("ThinkPad ACPI EC access misbehaving, falling back to ACPI TMPx access mode\n");
-                               thermal_read_mode = TPACPI_THERMAL_ACPI_TMP07;
-                       } else {
-                               pr_err("ThinkPad ACPI EC access misbehaving, disabling thermal sensors access\n");
-                               thermal_read_mode = TPACPI_THERMAL_NONE;
-                       }
-               } else {
-                       if (ver >= 3) {
-                               thermal_read_mode = TPACPI_THERMAL_TPEC_8;
-                               thermal_use_labels = true;
-                       } else {
-                               thermal_read_mode =
-                                       (ta2 != 0) ?
-                                       TPACPI_THERMAL_TPEC_16 : TPACPI_THERMAL_TPEC_8;
-                       }
-               }
-       } else if (acpi_tmp7) {
-               if (tpacpi_is_ibm() &&
-                   acpi_evalf(ec_handle, NULL, "UPDT", "qv")) {
-                       /* 600e/x, 770e, 770x */
-                       thermal_read_mode = TPACPI_THERMAL_ACPI_UPDT;
-               } else {
-                       /* IBM/LENOVO DSDT EC.TMPx access, max 8 sensors */
-                       thermal_read_mode = TPACPI_THERMAL_ACPI_TMP07;
-               }
-       } else {
-               /* temperatures not supported on 570, G4x, R30, R31, R32 */
-               thermal_read_mode = TPACPI_THERMAL_NONE;
-       }
+       thermal_read_mode = thermal_read_mode_check();
 
        vdbg_printk(TPACPI_DBG_INIT, "thermal is %s, mode %d\n",
                str_supported(thermal_read_mode != TPACPI_THERMAL_NONE),