Commit dbdaa582 authored by Amit Kucheria's avatar Amit Kucheria Committed by Eduardo Valentin
Browse files

drivers: thermal: tsens: simplify get_temp_tsens_v2 routine 



The current implementation is based on an algorithm published in the
docs. Instead of reading the temperature thrice w/o any explanation,
improve the algorithm.

This will become the basis for a common get_temp routine in the future.

Signed-off-by: default avatarAmit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: default avatarEduardo Valentin <edubezval@gmail.com>
parent 1b6e3e51

drivers/thermal/qcom/tsens-v2.c

+17 −38
Original line number Original line Diff line number Diff line
@@ -25,58 +25,37 @@ 
#define TM_Sn_STATUS_OFF		0x00a0

#define TM_Sn_STATUS_OFF		0x00a0

#define TM_TRDY_OFF			0x00e4

#define TM_TRDY_OFF			0x00e4





#define LAST_TEMP_MASK		0xfff

static int get_temp_tsens_v2(struct tsens_priv *priv, int i, int *temp)



static int get_temp_tsens_v2(struct tsens_priv *priv, int id, int *temp)

{

{

	struct tsens_sensor *s = &priv->sensor[id];

	struct tsens_sensor *s = &priv->sensor[i];

	u32 temp_idx = LAST_TEMP_0 + s->hw_id;

	u32 temp_idx = LAST_TEMP_0 + s->hw_id;

	u32 valid_idx = VALID_0 + s->hw_id;

	u32 valid_idx = VALID_0 + s->hw_id;

	u32 last_temp = 0, last_temp2 = 0, last_temp3 = 0, valid;

	u32 last_temp = 0, valid, mask;

	int ret;

	int ret;





	ret = regmap_field_read(priv->rf[temp_idx], &last_temp);

	if (ret)

		return ret;



	ret = regmap_field_read(priv->rf[valid_idx], &valid);

	ret = regmap_field_read(priv->rf[valid_idx], &valid);

	if (ret)

	if (ret)

		return ret;

		return ret;



	while (!valid) {

	if (valid)

		/* Valid bit is 0 for 6 AHB clock cycles.

		goto done;

		 * At 19.2MHz, 1 AHB clock is ~60ns.



		 * We should enter this loop very, very rarely.

	/* Try a second time */

		 */

		ndelay(400);

		ret = regmap_field_read(priv->rf[valid_idx], &valid);

		ret = regmap_field_read(priv->rf[valid_idx], &valid);

		if (ret)

		if (ret)

			return ret;

			return ret;

	ret = regmap_field_read(priv->rf[temp_idx], &last_temp2);

	if (ret)

		return ret;

	if (valid) {

		last_temp = last_temp2;

		goto done;

	}

	}





	/* Try a third/last time */

	/* Valid bit is set, OK to read the temperature */

	ret = regmap_field_read(priv->rf[valid_idx], &valid);

	ret = regmap_field_read(priv->rf[temp_idx], &last_temp);

	if (ret)

		return ret;

	ret = regmap_field_read(priv->rf[temp_idx], &last_temp3);

	if (ret)

	if (ret)

		return ret;

		return ret;

	if (valid) {

		last_temp = last_temp3;

		goto done;

	}





	if (last_temp == last_temp2)

	mask = GENMASK(priv->fields[LAST_TEMP_0].msb,

		last_temp = last_temp2;

		       priv->fields[LAST_TEMP_0].lsb);

	else if (last_temp2 == last_temp3)

		last_temp = last_temp3;

done:

	/* Convert temperature from deciCelsius to milliCelsius */

	/* Convert temperature from deciCelsius to milliCelsius */

	*temp = sign_extend32(last_temp, fls(LAST_TEMP_MASK) - 1) * 100;

	*temp = sign_extend32(last_temp, fls(mask) - 1) * 100;





	return 0;

	return 0;

}

}