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

[Amit Kucheria <amitk@kernel.org>]

Hi Dmitry,

I like this clean up.

On Sat, Sep 10, 2022 at 6:17 PM Dmitry Baryshkov
<dmitry.baryshkov@linaro.org> wrote:
>
> 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");

typo: separate

> +       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;

Have you verified that the p1 and p2 arrays end up with identical
values before and after this conversion?


> +       }
> +
> +       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;
> +}
> +
>  /*