thermal: tsens: Add support to split up register address space into two

There are two banks of registers for v2 TSENS IPs: SROT and TM. On older
SoCs these were contiguous, leading to DTs mapping them as one register
address space of size 0x2000. In newer SoCs, these two banks are not
contiguous anymore.

Add logic to init_common() to differentiate between old and new DTs and
adjust associated offsets for the TM register bank so that the old DTs will
continue to function correctly.

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

drivers/thermal/qcom/tsens-8996.c

@@ -16,7 +16,7 @@
 #include <linux/regmap.h>
 #include "tsens.h"
 
-#define STATUS_OFFSET	0x10a0
+#define STATUS_OFFSET	0xa0
 #define LAST_TEMP_MASK	0xfff
 #define STATUS_VALID_BIT	BIT(21)
 #define CODE_SIGN_BIT		BIT(11)
@@ -28,7 +28,7 @@ static int get_temp_8996(struct tsens_device *tmdev, int id, int *temp)
 	unsigned int sensor_addr;
 	int last_temp = 0, last_temp2 = 0, last_temp3 = 0, ret;
 
-	sensor_addr = STATUS_OFFSET + s->hw_id * 4;
+	sensor_addr = tmdev->tm_offset + STATUS_OFFSET + s->hw_id * 4;
 	ret = regmap_read(tmdev->map, sensor_addr, &code);
 	if (ret)
 		return ret;

drivers/thermal/qcom/tsens-common.c

@@ -16,6 +16,7 @@
 #include <linux/io.h>
 #include <linux/nvmem-consumer.h>
 #include <linux/of_address.h>
+#include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include "tsens.h"
@@ -126,11 +127,22 @@ static const struct regmap_config tsens_config = {
 int __init init_common(struct tsens_device *tmdev)
 {
 	void __iomem *base;
+	struct platform_device *op = of_find_device_by_node(tmdev->dev->of_node);
 
+	if (!op)
+		return -EINVAL;
 	base = of_iomap(tmdev->dev->of_node, 0);
 	if (!base)
 		return -EINVAL;
 
+	/* The driver only uses the TM register address space for now */
+	if (op->num_resources > 1) {
+		tmdev->tm_offset = 0;
+	} else {
+		/* old DTs where SROT and TM were in a contiguous 2K block */
+		tmdev->tm_offset = 0x1000;
+	}
+
 	tmdev->map = devm_regmap_init_mmio(tmdev->dev, base, &tsens_config);
 	if (IS_ERR(tmdev->map)) {
 		iounmap(base);

drivers/thermal/qcom/tsens.h

@@ -77,6 +77,7 @@ struct tsens_device {
 	struct device			*dev;
 	u32				num_sensors;
 	struct regmap			*map;
+	u32				tm_offset;
 	struct tsens_context		ctx;
 	const struct tsens_ops		*ops;
 	struct tsens_sensor		sensor[0];