Re: [PATCH v2 14/15] drivers: thermal: tsens: Create function to return sign-extended temperature

Stephen Boyd
2019-08-28T00:38:26Z

Quoting Amit Kucheria (2019-08-27 05:14:10)
> diff --git a/drivers/thermal/qcom/tsens-common.c b/drivers/thermal/qcom/tsens-common.c
> index ea2c46cc6a66a..06b44cfd5eab9 100644
> --- a/drivers/thermal/qcom/tsens-common.c
> +++ b/drivers/thermal/qcom/tsens-common.c
> @@ -84,13 +84,43 @@ static inline int code_to_degc(u32 adc_code, const struct tsens_sensor *s)
> return degc;
> }
>
> +/**
> + * tsens_hw_to_mC - Return sign-extended temperature in mCelsius.
> + * @s: Pointer to sensor struct

sensor? This isn't golang!

> + * @field: Index into regmap_field array pointing to temperature data
> + *
> + * This function handles temperature returned in ADC code or deciCelsius
> + * depending on IP version.
> + *
> + * Return: Temperature in milliCelsius on success, a negative errno will
> + * be returned in error cases
> + */
> +static int tsens_hw_to_mC(struct tsens_sensor *s, int field)
> +{
> + struct tsens_priv *priv = s->priv;
> + u32 temp = 0;
> + int ret;
> +
> + ret = regmap_field_read(priv->rf[field], &temp);
> + if (ret)
> + return ret;
> +
> + if (priv->feat->adc) {
> + /* Convert temperature from ADC code to milliCelsius */

Nitpick: Move this comment above the if and drop the braces.

> + return code_to_degc(temp, s) * 1000;
> + }
> +
> + /* deciCelsius -> milliCelsius along with sign extension */
> + return sign_extend32(temp, priv->tempres) * 100;
> +}
> +
> int get_temp_tsens_valid(struct tsens_sensor *s, int *temp)
> {
> struct tsens_priv *priv = s->priv;
> int hw_id = s->hw_id;
> u32 temp_idx = LAST_TEMP_0 + hw_id;
> u32 valid_idx = VALID_0 + hw_id;
> - u32 last_temp = 0, valid, mask;
> + u32 valid;
> int ret;
>
> ret = regmap_field_read(priv->rf[valid_idx], &valid);
> @@ -310,6 +328,10 @@ int __init init_common(struct tsens_priv *priv)
> goto err_put_device;
> }
> }
> +
> + /* Save away resolution of signed temperature value for this IP */
> + priv->tempres = priv->fields[LAST_TEMP_0].msb - priv->fields[LAST_TEMP_0].lsb;
> +

Why not just calculate this in the function that uses it? Is there a
reason to stash it away in the struct?

> for (i = 0, j = VALID_0; i < priv->feat->max_sensors; i++, j++) {
> priv->rf[j] = devm_regmap_field_alloc(dev, priv->tm_map,
> priv->fields[j]);