soc/qualcomm/common: Add Qualcomm TSENS support

Introduce a generic driver for the Qualcomm Temperature Sensor (TSENS)
V2 hardware block. This driver provides the infrastructure to read
temperature data from hardware status registers and monitor them
against software-defined thresholds.

The driver sign-extends the 12-bit raw temperature values and scales
the output to millidegrees Celsius for accurate monitoring.

TEST=Verify all x1p42100 thermal zones are readable on Google/Quartz.

Change-Id: I826df3f86edc30ac57d84f672b487a8b9b51728a
Signed-off-by: Kapil Porwal <kapilporwal@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/91609
Reviewed-by: Subrata Banik <subratabanik@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/qualcomm/common/Kconfig

@@ -54,4 +54,11 @@ config SOC_QUALCOMM_QCLIB_SKIP_MMU_TOGGLE
 	  flushes and TLB invalidations associated with mmu_disable() and
 	  mmu_enable() calls.
 
+config SOC_QUALCOMM_DEBUG_TSENS
+	bool
+	default n
+	help
+	  When enabled, a call to monitor TSENS will dump the sensor data on
+	  the debug console.
+
 endif

src/soc/qualcomm/common/include/soc/qcom_tsens.h

@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _SOC_QUALCOMM_TSENS_H_
+#define _SOC_QUALCOMM_TSENS_H_
+
+#include <stddef.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+#define TM_SN_STATUS_OFF    0x00a0
+#define SN_STATUS_VALID     (1 << 21)
+#define SN_STATUS_TEMP_MASK 0xFFF
+
+struct tsens_controller {
+	const char *name;
+	uintptr_t tm_base;
+	uintptr_t srot_base;
+	uint32_t sensor_count;
+};
+
+enum sensor_type {
+	TYPE_TSENS
+};
+
+struct thermal_zone_map {
+	const char *label;
+	enum sensor_type type;
+	const void *ctrl;
+	int hw_id;
+	int threshold;
+};
+
+/*
+ * Iterates through all defined zones and checks thresholds.
+ */
+void qcom_tsens_monitor_all(bool *has_crossed_threshold);
+
+/* External Data (Defined in SoC file) */
+extern const struct thermal_zone_map qcom_thermal_zones[];
+
+#endif /* _SOC_QUALCOMM_TSENS_H_ */

src/soc/qualcomm/common/tsens.c

@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <arch/mmio.h>
+#include <commonlib/bsd/stdlib.h>
+#include <device/mmio.h>
+#include <soc/addressmap.h>
+#include <soc/qcom_tsens.h>
+
+#if CONFIG(SOC_QUALCOMM_DEBUG_TSENS)
+#define thermal_printk(fmt, ...) printk(BIOS_INFO, fmt, ##__VA_ARGS__)
+#else
+#define thermal_printk(fmt, ...) do { (void)(fmt); } while (0)
+#endif
+
+static int read_tsens(const struct thermal_zone_map *zone, int *out)
+{
+	if (!zone)
+		return -1;
+
+	const struct tsens_controller *ctrl = (const struct tsens_controller *)zone->ctrl;
+	if (!ctrl || (zone->hw_id >= (int)ctrl->sensor_count))
+		return -1;
+
+	uintptr_t status_addr = ctrl->tm_base + TM_SN_STATUS_OFF + (zone->hw_id * 4);
+
+	uint32_t status = read32p(status_addr);
+	if (!(status & SN_STATUS_VALID))
+		return -2;
+
+	/* Sign extend 12-bit temperature and scale to milli C */
+	*out = ((int32_t)((status & SN_STATUS_TEMP_MASK) << 20) >> 20) * 100;
+	return 0;
+}
+
+void qcom_tsens_monitor_all(bool *has_crossed_threshold)
+{
+	if (!has_crossed_threshold)
+		return;
+
+	*has_crossed_threshold = false;
+
+	thermal_printk("\n------------------ Thermal Sensor State --------------------\n");
+	thermal_printk("%-15s | %-10s | %-8s | %-10s\n", "Zone", "Type", "Temp (C)", "Status");
+	thermal_printk("------------------------------------------------------------\n");
+
+	for (const struct thermal_zone_map *zone = qcom_thermal_zones; zone->label != NULL; zone++) {
+		int data = 0, status = -1;
+		const char *type_str = "UNK";
+		(void)type_str;
+
+		if (zone->type == TYPE_TSENS) {
+			type_str = "SoC";
+			status = read_tsens(zone, &data);
+		}
+
+		if (status == 0) {
+			thermal_printk("%-15s | %-10s | %3d.%1d    | ",
+			       zone->label, type_str, data / 1000, (data % 1000) / 100);
+
+			if (data >= zone->threshold) {
+				*has_crossed_threshold = true;
+				thermal_printk("EXCEEDED\n");
+				if (!CONFIG(SOC_QUALCOMM_DEBUG_TSENS))
+					return;
+			} else {
+				thermal_printk("OK\n");
+			}
+		} else {
+			thermal_printk("%-15s | %-10s | [ERR %d]  | -\n", zone->label, type_str, status);
+		}
+	}
+}