[PATCH v5 1/5] thermal/drivers/tsens: Add TSENS enable and calibration support for V2

[Praveenkumar I]

SoCs without RPM have to enable sensors and calibrate from the kernel.
Though TSENS IP supports 16 sensors, not all are used. So used hw_id
to enable the relevant sensors.

Added new calibration function for V2 as the tsens.c calib function
only supports V1.

Signed-off-by: Praveenkumar I <quic_ipkumar@xxxxxxxxxxx>
---
[v5]:
	Added bitfield.h to fix build error reported by kernel test robot.
	error: implicit declaration of function 'FIELD_PREP' is invalid in C99
[v4]:
	Named the values used inside the init_tsens_v2_no_rpm(), used
	FIELD_PREP() to get the Sn_CONVERSION data and some minor
	changes in the function variable order and array size.
[v3]:
	Renamed the init function and removed version check in it.
	Corrected the if check in init_common() at tsens.c
[v2]:
	Added separate init function for tsens v2 which calls init_common
	and initialize the remaining fields. Reformatted calibrate function
	and used hw_ids for sensors to enable.

 drivers/thermal/qcom/tsens-v2.c | 149 ++++++++++++++++++++++++++++++++
 drivers/thermal/qcom/tsens.c    |   2 +-
 drivers/thermal/qcom/tsens.h    |   3 +
 3 files changed, 153 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/qcom/tsens-v2.c b/drivers/thermal/qcom/tsens-v2.c
index 29a61d2d6ca3..7190e477b173 100644
--- a/drivers/thermal/qcom/tsens-v2.c
+++ b/drivers/thermal/qcom/tsens-v2.c
@@ -4,13 +4,32 @@
  * Copyright (c) 2018, Linaro Limited
  */
 
+#include <linux/bitfield.h>
 #include <linux/bitops.h>
 #include <linux/regmap.h>
+#include <linux/nvmem-consumer.h>
 #include "tsens.h"
 
 /* ----- SROT ------ */
 #define SROT_HW_VER_OFF	0x0000
 #define SROT_CTRL_OFF		0x0004
+#define SROT_MEASURE_PERIOD	0x0008
+#define SROT_Sn_CONVERSION	0x0060
+#define V2_SHIFT_DEFAULT	0x0003
+#define V2_SLOPE_DEFAULT	0x0cd0
+#define V2_CZERO_DEFAULT	0x016a
+#define ONE_PT_SLOPE		0x0cd0
+#define TWO_PT_SHIFTED_GAIN	921600
+#define ONE_PT_CZERO_CONST	94
+#define SW_RST_DEASSERT		0x0
+#define SW_RST_ASSERT		0x1
+#define MEASURE_PERIOD_2mSEC	0x1
+#define RSEULT_FORMAT_TEMP	0x1
+#define TSENS_ENABLE		0x1
+#define SENSOR_CONVERSION(n)	(((n) * 4) + SROT_Sn_CONVERSION)
+#define CONVERSION_SHIFT_MASK	GENMASK(24, 23)
+#define CONVERSION_SLOPE_MASK	GENMASK(22, 10)
+#define CONVERSION_CZERO_MASK	GENMASK(9, 0)
 
 /* ----- TM ------ */
 #define TM_INT_EN_OFF			0x0004
@@ -59,6 +78,11 @@ static const struct reg_field tsens_v2_regfields[MAX_REGFIELDS] = {
 	/* CTRL_OFF */
 	[TSENS_EN]     = REG_FIELD(SROT_CTRL_OFF,    0,  0),
 	[TSENS_SW_RST] = REG_FIELD(SROT_CTRL_OFF,    1,  1),
+	[SENSOR_EN]    = REG_FIELD(SROT_CTRL_OFF,    3,  18),
+	[CODE_OR_TEMP] = REG_FIELD(SROT_CTRL_OFF,    21, 21),
+
+	/* MAIN_MEASURE_PERIOD */
+	[MAIN_MEASURE_PERIOD] = REG_FIELD(SROT_MEASURE_PERIOD, 0, 7),
 
 	/* ----- TM ------ */
 	/* INTERRUPT ENABLE */
@@ -104,6 +128,131 @@ static const struct reg_field tsens_v2_regfields[MAX_REGFIELDS] = {
 	[TRDY] = REG_FIELD(TM_TRDY_OFF, 0, 0),
 };
 
+static int tsens_v2_calibrate_sensor(struct device *dev, struct tsens_sensor *sensor,
+				     struct regmap *map,  u32 mode, u32 base0, u32 base1)
+{
+	u32 slope, czero, val;
+	char name[8];
+	int ret;
+
+	/* Read offset value */
+	ret = snprintf(name, sizeof(name), "s%d", sensor->hw_id);
+	if (ret < 0)
+		return ret;
+
+	ret = nvmem_cell_read_variable_le_u32(dev, name, &sensor->offset);
+	if (ret)
+		return ret;
+
+	/* Based on calib mode, program SHIFT, SLOPE and CZERO */
+	switch (mode) {
+	case TWO_PT_CALIB:
+		slope = (TWO_PT_SHIFTED_GAIN / (base1 - base0));
+
+		czero = (base0 + sensor->offset - ((base1 - base0) / 3));
+
+		val = FIELD_PREP(CONVERSION_SHIFT_MASK, V2_SHIFT_DEFAULT) |
+		      FIELD_PREP(CONVERSION_SLOPE_MASK, slope) |
+		      FIELD_PREP(CONVERSION_CZERO_MASK, czero);
+
+		fallthrough;
+	case ONE_PT_CALIB2:
+		czero = base0 + sensor->offset - ONE_PT_CZERO_CONST;
+
+		val = FIELD_PREP(CONVERSION_SHIFT_MASK, V2_SHIFT_DEFAULT) |
+		      FIELD_PREP(CONVERSION_SLOPE_MASK, ONE_PT_SLOPE) |
+		      FIELD_PREP(CONVERSION_CZERO_MASK, czero);
+
+		break;
+	default:
+		dev_dbg(dev, "calibrationless mode\n");
+
+		val = FIELD_PREP(CONVERSION_SHIFT_MASK, V2_SHIFT_DEFAULT) |
+		      FIELD_PREP(CONVERSION_SLOPE_MASK, V2_SLOPE_DEFAULT) |
+		      FIELD_PREP(CONVERSION_CZERO_MASK, V2_CZERO_DEFAULT);
+	}
+
+	regmap_write(map, SENSOR_CONVERSION(sensor->hw_id), val);
+
+	return 0;
+}
+
+static int tsens_v2_calibration(struct tsens_priv *priv)
+{
+	struct device *dev = priv->dev;
+	u32 mode, base0, base1;
+	int i, ret;
+
+	if (priv->num_sensors > MAX_SENSORS)
+		return -EINVAL;
+
+	ret = nvmem_cell_read_variable_le_u32(priv->dev, "mode", &mode);
+	if (ret == -ENOENT)
+		dev_warn(priv->dev, "Calibration data not present in DT\n");
+	if (ret < 0)
+		return ret;
+
+	dev_dbg(priv->dev, "calibration mode is %d\n", mode);
+
+	ret = nvmem_cell_read_variable_le_u32(priv->dev, "base0", &base0);
+	if (ret < 0)
+		return ret;
+
+	ret = nvmem_cell_read_variable_le_u32(priv->dev, "base1", &base1);
+	if (ret < 0)
+		return ret;
+
+	/* Calibrate each sensor */
+	for (i = 0; i < priv->num_sensors; i++) {
+		ret = tsens_v2_calibrate_sensor(dev, &priv->sensor[i], priv->srot_map,
+						mode, base0, base1);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int __init init_tsens_v2_no_rpm(struct tsens_priv *priv)
+{
+	struct device *dev = priv->dev;
+	int i, ret;
+	u32 val = 0;
+
+	ret = init_common(priv);
+	if (ret < 0)
+		return ret;
+
+	priv->rf[CODE_OR_TEMP] = devm_regmap_field_alloc(dev, priv->srot_map,
+							 priv->fields[CODE_OR_TEMP]);
+	if (IS_ERR(priv->rf[CODE_OR_TEMP]))
+		return PTR_ERR(priv->rf[CODE_OR_TEMP]);
+
+	priv->rf[MAIN_MEASURE_PERIOD] = devm_regmap_field_alloc(dev, priv->srot_map,
+								priv->fields[MAIN_MEASURE_PERIOD]);
+	if (IS_ERR(priv->rf[MAIN_MEASURE_PERIOD]))
+		return PTR_ERR(priv->rf[MAIN_MEASURE_PERIOD]);
+
+	regmap_field_write(priv->rf[TSENS_SW_RST], SW_RST_ASSERT);
+
+	regmap_field_write(priv->rf[MAIN_MEASURE_PERIOD], MEASURE_PERIOD_2mSEC);
+
+	/* Enable available sensors */
+	for (i = 0; i < priv->num_sensors; i++)
+		val |= 1 << priv->sensor[i].hw_id;
+
+	regmap_field_write(priv->rf[SENSOR_EN], val);
+
+	/* Select temperature format, unit is deci-Celsius */
+	regmap_field_write(priv->rf[CODE_OR_TEMP], RSEULT_FORMAT_TEMP);
+
+	regmap_field_write(priv->rf[TSENS_SW_RST], SW_RST_DEASSERT);
+
+	regmap_field_write(priv->rf[TSENS_EN], TSENS_ENABLE);
+
+	return 0;
+}
+
 static const struct tsens_ops ops_generic_v2 = {
 	.init		= init_common,
 	.get_temp	= get_temp_tsens_valid,
diff --git a/drivers/thermal/qcom/tsens.c b/drivers/thermal/qcom/tsens.c
index 98c356acfe98..9dc0c2150948 100644
--- a/drivers/thermal/qcom/tsens.c
+++ b/drivers/thermal/qcom/tsens.c
@@ -974,7 +974,7 @@ int __init init_common(struct tsens_priv *priv)
 	ret = regmap_field_read(priv->rf[TSENS_EN], &enabled);
 	if (ret)
 		goto err_put_device;
-	if (!enabled) {
+	if (!enabled && (tsens_version(priv) != VER_2_X_NO_RPM)) {
 		dev_err(dev, "%s: device not enabled\n", __func__);
 		ret = -ENODEV;
 		goto err_put_device;
diff --git a/drivers/thermal/qcom/tsens.h b/drivers/thermal/qcom/tsens.h
index 2805de1c6827..b2e8f0f2b466 100644
--- a/drivers/thermal/qcom/tsens.h
+++ b/drivers/thermal/qcom/tsens.h
@@ -35,6 +35,7 @@ enum tsens_ver {
 	VER_0_1,
 	VER_1_X,
 	VER_2_X,
+	VER_2_X_NO_RPM,
 };
 
 enum tsens_irq_type {
@@ -168,6 +169,8 @@ enum regfield_ids {
 	TSENS_SW_RST,
 	SENSOR_EN,
 	CODE_OR_TEMP,
+	/* MEASURE_PERIOD */
+	MAIN_MEASURE_PERIOD,
 
 	/* ----- TM ------ */
 	/* TRDY */
-- 
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