[PATCH v8 3/4] drm: sun4i: Add support for enabling DDC I2C bus to sun8i_dw_hdmi glue

megous
2019-08-06T15:57:42Z

From: Ondrej Jirman <megous@megous.com>

Orange Pi 3 board requires enabling a voltage shifting circuit via GPIO
for the DDC bus to be usable.

Add support for hdmi-connector node's optional ddc-en-gpios property to
support this use case.

Signed-off-by: Ondrej Jirman <megous@megous.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@siol.net>
---
drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c | 54 +++++++++++++++++++++++++--
drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h | 2 +
2 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
index 8ca5af0c912f..a44dca4b0219 100644
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
@@ -97,10 +97,34 @@ static u32 sun8i_dw_hdmi_find_possible_crtcs(struct drm_device *drm,
return crtcs;
}

+static int sun8i_dw_hdmi_find_connector_pdev(struct device *dev,
+ struct platform_device **pdev_out)
+{
+ struct platform_device *pdev;
+ struct device_node *remote;
+
+ remote = of_graph_get_remote_node(dev->of_node, 1, -1);
+ if (!remote)
+ return -ENODEV;
+
+ if (!of_device_is_compatible(remote, "hdmi-connector")) {
+ of_node_put(remote);
+ return -ENODEV;
+ }
+
+ pdev = of_find_device_by_node(remote);
+ of_node_put(remote);
+ if (!pdev)
+ return -ENODEV;
+
+ *pdev_out = pdev;
+ return 0;
+}
+
static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
void *data)
{
- struct platform_device *pdev = to_platform_device(dev);
+ struct platform_device *pdev = to_platform_device(dev), *connector_pdev;
struct dw_hdmi_plat_data *plat_data;
struct drm_device *drm = data;
struct device_node *phy_node;
@@ -150,16 +174,30 @@ static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
return PTR_ERR(hdmi->regulator);
}

+ ret = sun8i_dw_hdmi_find_connector_pdev(dev, &connector_pdev);
+ if (!ret) {
+ hdmi->ddc_en = gpiod_get_optional(&connector_pdev->dev,
+ "ddc-en", GPIOD_OUT_HIGH);
+ platform_device_put(connector_pdev);
+
+ if (IS_ERR(hdmi->ddc_en)) {
+ dev_err(dev, "Couldn't get ddc-en gpio\n");
+ return PTR_ERR(hdmi->ddc_en);
+ }
+ }
+
ret = regulator_enable(hdmi->regulator);
if (ret) {
dev_err(dev, "Failed to enable regulator\n");
- return ret;
+ goto err_unref_ddc_en;
}

+ gpiod_set_value(hdmi->ddc_en, 1);
+
ret = reset_control_deassert(hdmi->rst_ctrl);
if (ret) {
dev_err(dev, "Could not deassert ctrl reset control\n");
- goto err_disable_regulator;
+ goto err_disable_ddc_en;
}

ret = clk_prepare_enable(hdmi->clk_tmds);
@@ -212,8 +250,12 @@ static int sun8i_dw_hdmi_bind(struct device *dev, struct device *master,
clk_disable_unprepare(hdmi->clk_tmds);
err_assert_ctrl_reset:
reset_control_assert(hdmi->rst_ctrl);
-err_disable_regulator:
+err_disable_ddc_en:
+ gpiod_set_value(hdmi->ddc_en, 0);
regulator_disable(hdmi->regulator);
+err_unref_ddc_en:
+ if (hdmi->ddc_en)
+ gpiod_put(hdmi->ddc_en);

return ret;
}
@@ -227,7 +269,11 @@ static void sun8i_dw_hdmi_unbind(struct device *dev, struct device *master,
sun8i_hdmi_phy_remove(hdmi);
clk_disable_unprepare(hdmi->clk_tmds);
reset_control_assert(hdmi->rst_ctrl);
+ gpiod_set_value(hdmi->ddc_en, 0);
regulator_disable(hdmi->regulator);
+
+ if (hdmi->ddc_en)
+ gpiod_put(hdmi->ddc_en);
}

static const struct component_ops sun8i_dw_hdmi_ops = {
diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
index 720c5aa8adc1..d707c9171824 100644
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
@@ -9,6 +9,7 @@
#include <drm/bridge/dw_hdmi.h>
#include <drm/drm_encoder.h>
#include <linux/clk.h>
+#include <linux/gpio/consumer.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/reset.h>
@@ -190,6 +191,7 @@ struct sun8i_dw_hdmi {
struct regulator *regulator;
const struct sun8i_dw_hdmi_quirks *quirks;
struct reset_control *rst_ctrl;
+ struct gpio_desc *ddc_en;
};

static inline struct sun8i_dw_hdmi *
--
2.22.0