thermal: rcar_thermal: update calculation formula for R-Car Gen3 SoCs

Update calculation for the R-Car Gen3 and RZ/G2 SoCs which have a
thermal IP block controlled by this driver. That is the:

* R-Car D3 (r8a77995)
* R-Car E2 (r8a77990)
* R-Car V3M (r8a77970)
* RZ/G2E (r8a774c0)

The calculation update is as documented in the R-Car Gen3 User's Manual,
v1.50 Nov 2018:

- When CTEMP is less than 24
   T = CTEMP[5:0] * 5.5 - 72
- When CTEMP is equal to/greater than 24
   T = CTEMP[5:0] * 5 - 60

This was inspired by a patch in the BSP by Van Do <van.do.xw@renesas.com>

Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Tested-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

diff --git a/drivers/thermal/rcar_thermal.c b/drivers/thermal/rcar_thermal.c
index 97462e9..d0873de 100644 (file)
--- a/drivers/thermal/rcar_thermal.c
+++ b/drivers/thermal/rcar_thermal.c
@@ -52,6 +52,7 @@ struct rcar_thermal_chip {
        unsigned int irq_per_ch : 1;
        unsigned int needs_suspend_resume : 1;
        unsigned int nirqs;
+       unsigned int ctemp_bands;
 };
 
 static const struct rcar_thermal_chip rcar_thermal = {
@@ -60,6 +61,7 @@ static const struct rcar_thermal_chip rcar_thermal = {
        .irq_per_ch = 0,
        .needs_suspend_resume = 0,
        .nirqs = 1,
+       .ctemp_bands = 1,
 };
 
 static const struct rcar_thermal_chip rcar_gen2_thermal = {
@@ -68,6 +70,7 @@ static const struct rcar_thermal_chip rcar_gen2_thermal = {
        .irq_per_ch = 0,
        .needs_suspend_resume = 0,
        .nirqs = 1,
+       .ctemp_bands = 1,
 };
 
 static const struct rcar_thermal_chip rcar_gen3_thermal = {
@@ -80,6 +83,7 @@ static const struct rcar_thermal_chip rcar_gen3_thermal = {
         * interrupts to detect a temperature change, rise or fall.
         */
        .nirqs = 2,
+       .ctemp_bands = 2,
 };
 
 struct rcar_thermal_priv {
@@ -263,7 +267,12 @@ static int rcar_thermal_get_current_temp(struct rcar_thermal_priv *priv,
                return ret;
 
        mutex_lock(&priv->lock);
-       tmp =  MCELSIUS((priv->ctemp * 5) - 65);
+       if (priv->chip->ctemp_bands == 1)
+               tmp = MCELSIUS((priv->ctemp * 5) - 65);
+       else if (priv->ctemp < 24)
+               tmp = MCELSIUS(((priv->ctemp * 55) - 720) / 10);
+       else
+               tmp = MCELSIUS((priv->ctemp * 5) - 60);
        mutex_unlock(&priv->lock);
 
        if ((tmp < MCELSIUS(-45)) || (tmp > MCELSIUS(125))) {