drm/tegra: dpaux: Add helpers for setting up pads

In preparation for adding pinctrl support for the DPAUX pads, add a
couple of helpers functions to configure the pads and control their
power.

Please note that although a simple if-statement could be used instead
of a case statement for configuring the pads as there are only two
possible modes, a case statement is used because when integrating with
the pinctrl framework, we need to be able to handle invalid modes that
could be passed.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --git a/drivers/gpu/drm/tegra/dpaux.c b/drivers/gpu/drm/tegra/dpaux.c
index 0874a7e5b37b50e188b9c70254b5eb90437e7794..b0b1f84e98b1abc4a888e0e23aebe5731337fffc 100644 (file)
--- a/drivers/gpu/drm/tegra/dpaux.c
+++ b/drivers/gpu/drm/tegra/dpaux.c
@@ -267,6 +267,53 @@ static irqreturn_t tegra_dpaux_irq(int irq, void *data)
        return ret;
 }
 
+static void tegra_dpaux_pad_power_down(struct tegra_dpaux *dpaux)
+{
+       u32 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
+
+       value |= DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
+
+       tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
+}
+
+static void tegra_dpaux_pad_power_up(struct tegra_dpaux *dpaux)
+{
+       u32 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
+
+       value &= ~DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
+
+       tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
+}
+
+static int tegra_dpaux_pad_config(struct tegra_dpaux *dpaux, unsigned function)
+{
+       u32 value;
+
+       switch (function) {
+       case DPAUX_HYBRID_PADCTL_MODE_AUX:
+               value = DPAUX_HYBRID_PADCTL_AUX_CMH(2) |
+                       DPAUX_HYBRID_PADCTL_AUX_DRVZ(4) |
+                       DPAUX_HYBRID_PADCTL_AUX_DRVI(0x18) |
+                       DPAUX_HYBRID_PADCTL_AUX_INPUT_RCV |
+                       DPAUX_HYBRID_PADCTL_MODE_AUX;
+               break;
+
+       case DPAUX_HYBRID_PADCTL_MODE_I2C:
+               value = DPAUX_HYBRID_PADCTL_I2C_SDA_INPUT_RCV |
+                       DPAUX_HYBRID_PADCTL_I2C_SCL_INPUT_RCV |
+                       DPAUX_HYBRID_PADCTL_MODE_I2C;
+               break;
+
+       default:
+               return -ENOTSUPP;
+       }
+
+       tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_PADCTL);
+       tegra_dpaux_pad_power_up(dpaux);
+
+       return 0;
+}
+
 static int tegra_dpaux_probe(struct platform_device *pdev)
 {
        struct tegra_dpaux *dpaux;
@@ -372,15 +419,9 @@ static int tegra_dpaux_probe(struct platform_device *pdev)
         * is no possibility to perform the I2C mode configuration in the
         * HDMI path.
         */
-       value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
-       value &= ~DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
-       tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
-
-       value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_PADCTL);
-       value = DPAUX_HYBRID_PADCTL_I2C_SDA_INPUT_RCV |
-               DPAUX_HYBRID_PADCTL_I2C_SCL_INPUT_RCV |
-               DPAUX_HYBRID_PADCTL_MODE_I2C;
-       tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_PADCTL);
+       err = tegra_dpaux_pad_config(dpaux, DPAUX_HYBRID_PADCTL_MODE_I2C);
+       if (err < 0)
+               return err;
 
        /* enable and clear all interrupts */
        value = DPAUX_INTR_AUX_DONE | DPAUX_INTR_IRQ_EVENT |
@@ -408,12 +449,9 @@ assert_reset:
 static int tegra_dpaux_remove(struct platform_device *pdev)
 {
        struct tegra_dpaux *dpaux = platform_get_drvdata(pdev);
-       u32 value;
 
        /* make sure pads are powered down when not in use */
-       value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
-       value |= DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
-       tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
+       tegra_dpaux_pad_power_down(dpaux);
 
        drm_dp_aux_unregister(&dpaux->aux);
 
@@ -538,30 +576,15 @@ enum drm_connector_status drm_dp_aux_detect(struct drm_dp_aux *aux)
 int drm_dp_aux_enable(struct drm_dp_aux *aux)
 {
        struct tegra_dpaux *dpaux = to_dpaux(aux);
-       u32 value;
-
-       value = DPAUX_HYBRID_PADCTL_AUX_CMH(2) |
-               DPAUX_HYBRID_PADCTL_AUX_DRVZ(4) |
-               DPAUX_HYBRID_PADCTL_AUX_DRVI(0x18) |
-               DPAUX_HYBRID_PADCTL_AUX_INPUT_RCV |
-               DPAUX_HYBRID_PADCTL_MODE_AUX;
-       tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_PADCTL);
-
-       value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
-       value &= ~DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
-       tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
 
-       return 0;
+       return tegra_dpaux_pad_config(dpaux, DPAUX_HYBRID_PADCTL_MODE_AUX);
 }
 
 int drm_dp_aux_disable(struct drm_dp_aux *aux)
 {
        struct tegra_dpaux *dpaux = to_dpaux(aux);
-       u32 value;
 
-       value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
-       value |= DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
-       tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
+       tegra_dpaux_pad_power_down(dpaux);
 
        return 0;
 }