Re: [PATCH v3 05/11] thermal: armada: Add support for Armada AP806

Gregory CLEMENT
2017-12-14T11:05:43Z

Hi Miquel,

On jeu., déc. 14 2017, Miquel Raynal <miquel.raynal-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> wrote:

> From: Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>
>
> The AP806 component is integrated in the Armada 8k and 7k lines of
> processors.
>
> The thermal sensor sample field on the status register is a signed
> value. Extend armada_get_temp() to handle signed values.
>
> Signed-off-by: Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>
> Signed-off-by: Miquel Raynal <miquel.raynal-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>

Maybe you should mention that you have made some changes at least to be
able to use the previous modification you have done.

> ---
> drivers/thermal/armada_thermal.c | 51 ++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 49 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/thermal/armada_thermal.c b/drivers/thermal/armada_thermal.c
> index e5b184cee79b..279d01937bb8 100644
> --- a/drivers/thermal/armada_thermal.c
> +++ b/drivers/thermal/armada_thermal.c
> @@ -47,6 +47,11 @@
> #define CONTROL0_OFFSET 0x0
> #define CONTROL1_OFFSET 0x4
>
> +/* TSEN refers to the temperature sensors within the AP */
> +#define CONTROL0_TSEN_START BIT(0)
> +#define CONTROL0_TSEN_RESET BIT(1)
> +#define CONTROL0_TSEN_ENABLE BIT(2)
> +
> struct armada_thermal_data;
>
> /* Marvell EBU Thermal Sensor Dev Structure */
> @@ -70,6 +75,7 @@ struct armada_thermal_data {
> unsigned long coef_m;
> unsigned long coef_div;
> bool inverted;
> + bool signed_sample;
>
> /* Register shift and mask to access the sensor temperature */
> unsigned int temp_shift;
> @@ -154,6 +160,24 @@ static void armada380_init_sensor(struct platform_device *pdev,
> }
> }
>
> +static void armada_ap806_init_sensor(struct platform_device *pdev,
> + struct armada_thermal_priv *priv)
> +{
> + u32 reg;
> +
> + if (!priv->control0) {
> + dev_err(&pdev->dev,
> + "Cannot access to control0 (control LSB) register\n");
> + return;
> + }
> +
> + reg = readl_relaxed(priv->control0);
> + reg &= ~CONTROL0_TSEN_RESET;
> + reg |= CONTROL0_TSEN_START | CONTROL0_TSEN_ENABLE;
> + writel(reg, priv->control0);
> + msleep(10);
> +}
> +
> static bool armada_is_valid(struct armada_thermal_priv *priv)
> {
> u32 reg = readl_relaxed(priv->status);
> @@ -167,6 +191,7 @@ static int armada_get_temp(struct thermal_zone_device *thermal,
> struct armada_thermal_priv *priv = thermal->devdata;
> u32 reg;
> unsigned long m, b, div;
> + int sample;
>
> /* Valid check */
> if (priv->data->is_valid && !priv->data->is_valid(priv)) {
> @@ -177,6 +202,11 @@ static int armada_get_temp(struct thermal_zone_device *thermal,
>
> reg = readl_relaxed(priv->status);
> reg = (reg >> priv->data->temp_shift) & priv->data->temp_mask;
> + if (priv->data->signed_sample)
> + /* The most significant bit is the sign bit */
> + sample = sign_extend32(reg, fls(priv->data->temp_mask) - 1);
> + else
> + sample = reg;
>
> /* Get formula coeficients */
> b = priv->data->coef_b;
> @@ -184,9 +214,9 @@ static int armada_get_temp(struct thermal_zone_device *thermal,
> div = priv->data->coef_div;
>
> if (priv->data->inverted)
> - *temp = ((m * reg) - b) / div;
> + *temp = ((m * sample) - b) / div;
> else
> - *temp = (b - (m * reg)) / div;
> + *temp = (b - (m * sample)) / div;
> return 0;
> }
>
> @@ -237,6 +267,19 @@ static const struct armada_thermal_data armada380_data = {
> .inverted = true,
> };
>
> +static const struct armada_thermal_data armada_ap806_data = {
> + .is_valid = armada_is_valid,
> + .init_sensor = armada_ap806_init_sensor,
> + .is_valid_bit = BIT(16),
> + .temp_shift = 0,
> + .temp_mask = 0x3ff,
> + .coef_b = -150000,

Don't you expect any side effect by storing a negative value in a
unsigned variable?

Thanks,

Gregory

> + .coef_m = 423UL,
> + .coef_div = 1,
> + .inverted = true,
> + .signed_sample = true,
> +};
> +
> static const struct of_device_id armada_thermal_id_table[] = {
> {
> .compatible = "marvell,armadaxp-thermal",
> @@ -255,6 +298,10 @@ static const struct of_device_id armada_thermal_id_table[] = {
> .data = &armada380_data,
> },
> {
> + .compatible = "marvell,armada-ap806-thermal",
> + .data = &armada_ap806_data,
> + },
> + {
> /* sentinel */
> },
> };
> --
> 2.11.0
>
>
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--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.