[PATCH 03/12] drm/tegra: Add helper functions for setting up DPAUX pads

Jon Hunter
2016-06-23T15:58:56Z

In preparation for adding pinctrl support for the DPAUX pads, add
helpers functions for configuring the pads and controlling the power
for the pads.

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-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
drivers/gpu/drm/tegra/dpaux.c | 81 +++++++++++++++++++++++++++----------------
1 file changed, 51 insertions(+), 30 deletions(-)

diff --git a/drivers/gpu/drm/tegra/dpaux.c b/drivers/gpu/drm/tegra/dpaux.c
index 0874a7e5b37b..4014ec57ed31 100644
--- a/drivers/gpu/drm/tegra/dpaux.c
+++ b/drivers/gpu/drm/tegra/dpaux.c
@@ -267,6 +267,51 @@ 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 +417,9 @@ 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 +447,9 @@ 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 +574,15 @@ 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;
}
--
2.1.4

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