thermal/drivers/qcom-spmi-temp-alarm: Enable stage 2 shutdown when required

Certain TEMP_ALARM GEN2 PMIC peripherals need over-temperature stage 2
automatic PMIC partial shutdown. This will ensure that in the event of
reaching the hotter stage 3 over-temperature threshold, repeated faults
will be avoided during the automatic PMIC hardware full shutdown.
Modify the stage 2 shutdown control logic to ensure that stage 2
shutdown is enabled on all affected PMICs. Read the digital major
and minor revision registers to identify these PMICs.

Signed-off-by: David Collins <david.collins@oss.qualcomm.com>
Signed-off-by: Anjelique Melendez <anjelique.melendez@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250710224555.3047790-2-anjelique.melendez@oss.qualcomm.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Author: David Collins

drivers/thermal/qcom/qcom-spmi-temp-alarm.c

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2011-2015, 2017, 2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
  */
 
 #include <linux/bitops.h>
@@ -16,6 +17,7 @@
 
 #include "../thermal_hwmon.h"
 
+#define QPNP_TM_REG_DIG_MINOR		0x00
 #define QPNP_TM_REG_DIG_MAJOR		0x01
 #define QPNP_TM_REG_TYPE		0x04
 #define QPNP_TM_REG_SUBTYPE		0x05
@@ -31,7 +33,7 @@
 #define STATUS_GEN2_STATE_MASK		GENMASK(6, 4)
 #define STATUS_GEN2_STATE_SHIFT		4
 
-#define SHUTDOWN_CTRL1_OVERRIDE_S2	BIT(6)
+#define SHUTDOWN_CTRL1_OVERRIDE_STAGE2	BIT(6)
 #define SHUTDOWN_CTRL1_THRESHOLD_MASK	GENMASK(1, 0)
 
 #define SHUTDOWN_CTRL1_RATE_25HZ	BIT(3)
@@ -78,6 +80,7 @@ struct qpnp_tm_chip {
 	/* protects .thresh, .stage and chip registers */
 	struct mutex			lock;
 	bool				initialized;
+	bool				require_stage2_shutdown;
 
 	struct iio_channel		*adc;
 	const long			(*temp_map)[THRESH_COUNT][STAGE_COUNT];
@@ -220,13 +223,13 @@ static int qpnp_tm_update_critical_trip_temp(struct qpnp_tm_chip *chip,
 {
 	long stage2_threshold_min = (*chip->temp_map)[THRESH_MIN][1];
 	long stage2_threshold_max = (*chip->temp_map)[THRESH_MAX][1];
-	bool disable_s2_shutdown = false;
+	bool disable_stage2_shutdown = false;
 	u8 reg;
 
 	WARN_ON(!mutex_is_locked(&chip->lock));
 
 	/*
-	 * Default: S2 and S3 shutdown enabled, thresholds at
+	 * Default: Stage 2 and Stage 3 shutdown enabled, thresholds at
 	 * lowest threshold set, monitoring at 25Hz
 	 */
 	reg = SHUTDOWN_CTRL1_RATE_25HZ;
@@ -241,12 +244,12 @@ static int qpnp_tm_update_critical_trip_temp(struct qpnp_tm_chip *chip,
 		chip->thresh = THRESH_MAX -
 			((stage2_threshold_max - temp) /
 			 TEMP_THRESH_STEP);
-		disable_s2_shutdown = true;
+		disable_stage2_shutdown = true;
 	} else {
 		chip->thresh = THRESH_MAX;
 
 		if (chip->adc)
-			disable_s2_shutdown = true;
+			disable_stage2_shutdown = true;
 		else
 			dev_warn(chip->dev,
 				 "No ADC is configured and critical temperature %d mC is above the maximum stage 2 threshold of %ld mC! Configuring stage 2 shutdown at %ld mC.\n",
@@ -255,8 +258,8 @@ static int qpnp_tm_update_critical_trip_temp(struct qpnp_tm_chip *chip,
 
 skip:
 	reg |= chip->thresh;
-	if (disable_s2_shutdown)
-		reg |= SHUTDOWN_CTRL1_OVERRIDE_S2;
+	if (disable_stage2_shutdown && !chip->require_stage2_shutdown)
+		reg |= SHUTDOWN_CTRL1_OVERRIDE_STAGE2;
 
 	return qpnp_tm_write(chip, QPNP_TM_REG_SHUTDOWN_CTRL1, reg);
 }
@@ -350,8 +353,8 @@ static int qpnp_tm_probe(struct platform_device *pdev)
 {
 	struct qpnp_tm_chip *chip;
 	struct device_node *node;
-	u8 type, subtype, dig_major;
-	u32 res;
+	u8 type, subtype, dig_major, dig_minor;
+	u32 res, dig_revision;
 	int ret, irq;
 
 	node = pdev->dev.of_node;
@@ -402,6 +405,11 @@ static int qpnp_tm_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, ret,
 				     "could not read dig_major\n");
 
+	ret = qpnp_tm_read(chip, QPNP_TM_REG_DIG_MINOR, &dig_minor);
+	if (ret < 0)
+		return dev_err_probe(&pdev->dev, ret,
+				     "could not read dig_minor\n");
+
 	if (type != QPNP_TM_TYPE || (subtype != QPNP_TM_SUBTYPE_GEN1
 				     && subtype != QPNP_TM_SUBTYPE_GEN2)) {
 		dev_err(&pdev->dev, "invalid type 0x%02x or subtype 0x%02x\n",
@@ -415,6 +423,23 @@ static int qpnp_tm_probe(struct platform_device *pdev)
 	else
 		chip->temp_map = &temp_map_gen1;
 
+	if (chip->subtype == QPNP_TM_SUBTYPE_GEN2) {
+		dig_revision = (dig_major << 8) | dig_minor;
+		/*
+		 * Check if stage 2 automatic partial shutdown must remain
+		 * enabled to avoid potential repeated faults upon reaching
+		 * over-temperature stage 3.
+		 */
+		switch (dig_revision) {
+		case 0x0001:
+		case 0x0002:
+		case 0x0100:
+		case 0x0101:
+			chip->require_stage2_shutdown = true;
+			break;
+		}
+	}
+
 	/*
 	 * Register the sensor before initializing the hardware to be able to
 	 * read the trip points. get_temp() returns the default temperature