[PATCH 1/2] platform/x86: thinkpad_acpi: Simplify thermal mode checking

From: Vishnu Sankar
Date: Wed Feb 14 2024 - 00:30:52 EST


Add a thermal_read_mode_check helper function to make the code
simpler during init.
This helps particularly when the new TPEC_12 mode is added in
the next patch.

Suggested-by: Ilpo Jarvinen <ilpo.jarvinen@xxxxxxxxx>
Signed-off-by: Vishnu Sankar <vishnuocv@xxxxxxxxx>
---
drivers/platform/x86/thinkpad_acpi.c | 136 +++++++++++++--------------
1 file changed, 66 insertions(+), 70 deletions(-)

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index c4895e9bc714..2428c8bd0fa2 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -6147,6 +6147,71 @@ 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 thermal_read_mode_check(void)
+{
+ u8 t, ta1, ta2, ver = 0;
+ int i;
+
+ 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) {
+ 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_evalf(ec_handle, NULL, "TMP7", "qv")) {
+ 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 +6440,9 @@ 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),
--
2.34.1