[RFC PATCH 02/10] thermal/drivers/tsens: Support using nvmem cells for calibration data

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

Add a unified function using nvmem cells for parsing the calibration
data rather than parsing the calibration blob manually.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/thermal/qcom/tsens-v0_1.c | 15 ++++++++
 drivers/thermal/qcom/tsens-v1.c   |  6 ++-
 drivers/thermal/qcom/tsens.c      | 62 +++++++++++++++++++++++++++++++
 drivers/thermal/qcom/tsens.h      |  4 ++
 4 files changed, 86 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/qcom/tsens-v0_1.c b/drivers/thermal/qcom/tsens-v0_1.c
index f136cb350238..2974eea578f4 100644
--- a/drivers/thermal/qcom/tsens-v0_1.c
+++ b/drivers/thermal/qcom/tsens-v0_1.c
@@ -229,6 +229,11 @@ static int calibrate_8916(struct tsens_priv *priv)
 	u32 p1[5], p2[5];
 	int mode = 0;
 	u32 *qfprom_cdata, *qfprom_csel;
+	int ret;
+
+	ret = tsens_calibrate_nvmem(priv, 3);
+	if (!ret)
+		return 0;
 
 	qfprom_cdata = (u32 *)qfprom_read(priv->dev, "calib");
 	if (IS_ERR(qfprom_cdata))
@@ -286,6 +291,11 @@ static int calibrate_8939(struct tsens_priv *priv)
 	int mode = 0;
 	u32 *qfprom_cdata;
 	u32 cdata[6];
+	int ret;
+
+	ret = tsens_calibrate_nvmem(priv, 2);
+	if (!ret)
+		return 0;
 
 	qfprom_cdata = (u32 *)qfprom_read(priv->dev, "calib");
 	if (IS_ERR(qfprom_cdata))
@@ -491,6 +501,11 @@ static int calibrate_9607(struct tsens_priv *priv)
 	u32 p1[5], p2[5];
 	int mode = 0;
 	u32 *qfprom_cdata;
+	int ret;
+
+	ret = tsens_calibrate_nvmem(priv, 2);
+	if (!ret)
+		return 0;
 
 	qfprom_cdata = (u32 *)qfprom_read(priv->dev, "calib");
 	if (IS_ERR(qfprom_cdata))
diff --git a/drivers/thermal/qcom/tsens-v1.c b/drivers/thermal/qcom/tsens-v1.c
index 573e261ccca7..868d7b4c9e36 100644
--- a/drivers/thermal/qcom/tsens-v1.c
+++ b/drivers/thermal/qcom/tsens-v1.c
@@ -172,7 +172,11 @@ static int calibrate_v1(struct tsens_priv *priv)
 	u32 p1[10], p2[10];
 	u32 mode = 0, lsb = 0, msb = 0;
 	u32 *qfprom_cdata;
-	int i;
+	int i, ret;
+
+	ret = tsens_calibrate_nvmem(priv, 2);
+	if (!ret)
+		return 0;
 
 	qfprom_cdata = (u32 *)qfprom_read(priv->dev, "calib");
 	if (IS_ERR(qfprom_cdata))
diff --git a/drivers/thermal/qcom/tsens.c b/drivers/thermal/qcom/tsens.c
index e49f58e83513..8331b924325a 100644
--- a/drivers/thermal/qcom/tsens.c
+++ b/drivers/thermal/qcom/tsens.c
@@ -70,6 +70,68 @@ char *qfprom_read(struct device *dev, const char *cname)
 	return ret;
 }
 
+int tsens_calibrate_nvmem(struct tsens_priv *priv, int shift)
+{
+	u32 mode;
+	u32 base1, base2;
+	u32 p1[MAX_SENSORS], p2[MAX_SENSORS];
+	char name[] = "sX_pY";
+	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, "Please migrate to sepate nvmem cells for calibration data\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, "base1", &base1);
+	if (ret < 0)
+		return ret;
+
+	ret = nvmem_cell_read_variable_le_u32(priv->dev, "base2", &base2);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < priv->num_sensors; i++) {
+		ret = snprintf(name, sizeof(name), "s%d_p1", i);
+		if (ret < 0)
+			return ret;
+
+		ret = nvmem_cell_read_variable_le_u32(priv->dev, name, &p1[i]);
+		if (ret)
+			return ret;
+
+		p1[i] = (base1 + p1[i]) << shift;
+
+		ret = snprintf(name, sizeof(name), "s%d_p2", i);
+		if (ret < 0)
+			return ret;
+
+		ret = nvmem_cell_read_variable_le_u32(priv->dev, name, &p2[i]);
+		if (ret)
+			return ret;
+
+		p2[i] = (base2 + p2[i]) << shift;
+	}
+
+	if (mode == NO_PT_CALIB) {
+		dev_dbg(priv->dev, "calibrationless mode\n");
+		for (i = 0; i < priv->num_sensors; i++) {
+			p1[i] = 500;
+			p2[i] = 780;
+		}
+	}
+
+	compute_intercept_slope(priv, p1, p2, mode);
+
+	return 0;
+}
+
 /*
  * Use this function on devices where slope and offset calculations
  * depend on calibration data read from qfprom. On others the slope
diff --git a/drivers/thermal/qcom/tsens.h b/drivers/thermal/qcom/tsens.h
index ba05c8233356..504ed3394a79 100644
--- a/drivers/thermal/qcom/tsens.h
+++ b/drivers/thermal/qcom/tsens.h
@@ -6,6 +6,7 @@
 #ifndef __QCOM_TSENS_H__
 #define __QCOM_TSENS_H__
 
+#define NO_PT_CALIB		0x0
 #define ONE_PT_CALIB		0x1
 #define ONE_PT_CALIB2		0x2
 #define TWO_PT_CALIB		0x3
@@ -17,6 +18,8 @@
 #define THRESHOLD_MAX_ADC_CODE	0x3ff
 #define THRESHOLD_MIN_ADC_CODE	0x0
 
+#define MAX_SENSORS 16
+
 #include <linux/interrupt.h>
 #include <linux/thermal.h>
 #include <linux/regmap.h>
@@ -576,6 +579,7 @@ struct tsens_priv {
 };
 
 char *qfprom_read(struct device *dev, const char *cname);
+int tsens_calibrate_nvmem(struct tsens_priv *priv, int shift);
 void compute_intercept_slope(struct tsens_priv *priv, u32 *pt1, u32 *pt2, u32 mode);
 int init_common(struct tsens_priv *priv);
 int get_temp_tsens_valid(const struct tsens_sensor *s, int *temp);
-- 
2.35.1