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

[Gregory CLEMENT <gregory.clement-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>]

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.
http://free-electrons.com
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