Re: [PATCH 3/3] drm/omap: displays: encoder-tpd12s015: Support for hot plug detection

From: Laurent Pinchart
Date: Tue May 23 2017 - 05:48:18 EST


Hi Peter,

Thank you for the patch.

On Monday 15 May 2017 12:03:12 Peter Ujfalusi wrote:
> Use interrupt handler for hpd GPIO to react to HPD changes.
>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
> ---
> .../gpu/drm/omapdrm/displays/encoder-tpd12s015.c | 81 +++++++++++++++++++
> 1 file changed, 81 insertions(+)
>
> diff --git a/drivers/gpu/drm/omapdrm/displays/encoder-tpd12s015.c
> b/drivers/gpu/drm/omapdrm/displays/encoder-tpd12s015.c index
> 58276a48112e..529b8509dd99 100644
> --- a/drivers/gpu/drm/omapdrm/displays/encoder-tpd12s015.c
> +++ b/drivers/gpu/drm/omapdrm/displays/encoder-tpd12s015.c
> @@ -15,12 +15,17 @@
> #include <linux/slab.h>
> #include <linux/platform_device.h>
> #include <linux/gpio/consumer.h>
> +#include <linux/spinlock.h>

Did you mean linux/mutex.h ?

>
> #include "../dss/omapdss.h"
>
> struct panel_drv_data {
> struct omap_dss_device dssdev;
> struct omap_dss_device *in;
> + void (*hpd_cb)(void *cb_data, enum drm_connector_status status);
> + void *hpd_cb_data;
> + bool hpd_enabled;
> + struct mutex hpd_lock;
>
> struct gpio_desc *ct_cp_hpd_gpio;
> struct gpio_desc *ls_oe_gpio;
> @@ -162,6 +167,49 @@ static bool tpd_detect(struct omap_dss_device *dssdev)
> return gpiod_get_value_cansleep(ddata->hpd_gpio);
> }
>
> +static int tpd_register_hpd_cb(struct omap_dss_device *dssdev,
> + void (*cb)(void *cb_data,
> + enum drm_connector_status status),
> + void *cb_data)
> +{
> + struct panel_drv_data *ddata = to_panel_data(dssdev);
> +
> + mutex_lock(&ddata->hpd_lock);
> + ddata->hpd_cb = cb;
> + ddata->hpd_cb_data = cb_data;
> + mutex_unlock(&ddata->hpd_lock);
> +
> + return 0;
> +}
> +
> +static void tpd_unregister_hpd_cb(struct omap_dss_device *dssdev)
> +{
> + struct panel_drv_data *ddata = to_panel_data(dssdev);
> +
> + mutex_lock(&ddata->hpd_lock);
> + ddata->hpd_cb = NULL;
> + ddata->hpd_cb_data = NULL;
> + mutex_unlock(&ddata->hpd_lock);
> +}
> +
> +static void tpd_enable_hpd(struct omap_dss_device *dssdev)
> +{
> + struct panel_drv_data *ddata = to_panel_data(dssdev);
> +
> + mutex_lock(&ddata->hpd_lock);
> + ddata->hpd_enabled = true;
> + mutex_unlock(&ddata->hpd_lock);
> +}
> +
> +static void tpd_disable_hpd(struct omap_dss_device *dssdev)
> +{
> + struct panel_drv_data *ddata = to_panel_data(dssdev);
> +
> + mutex_lock(&ddata->hpd_lock);
> + ddata->hpd_enabled = false;
> + mutex_unlock(&ddata->hpd_lock);
> +}
> +
> static int tpd_set_infoframe(struct omap_dss_device *dssdev,
> const struct hdmi_avi_infoframe *avi)
> {
> @@ -193,10 +241,34 @@ static const struct omapdss_hdmi_ops tpd_hdmi_ops = {
>
> .read_edid = tpd_read_edid,
> .detect = tpd_detect,
> + .register_hpd_cb = tpd_register_hpd_cb,
> + .unregister_hpd_cb = tpd_unregister_hpd_cb,
> + .enable_hpd = tpd_enable_hpd,
> + .disable_hpd = tpd_disable_hpd,
> .set_infoframe = tpd_set_infoframe,
> .set_hdmi_mode = tpd_set_hdmi_mode,
> };
>
> +static irqreturn_t tpd_hpd_isr(int irq, void *data)
> +{
> + struct panel_drv_data *ddata = data;
> +
> + mutex_lock(&ddata->hpd_lock);
> + if (ddata->hpd_enabled && ddata->hpd_cb) {
> + enum drm_connector_status status;
> +
> + if (tpd_detect(&ddata->dssdev))
> + status = connector_status_connected;
> + else
> + status = connector_status_disconnected;
> +
> + ddata->hpd_cb(ddata->hpd_cb_data, status);
> + }
> + mutex_unlock(&ddata->hpd_lock);
> +
> + return IRQ_HANDLED;
> +}
> +
> static int tpd_probe_of(struct platform_device *pdev)
> {
> struct panel_drv_data *ddata = platform_get_drvdata(pdev);
> @@ -261,6 +333,15 @@ static int tpd_probe(struct platform_device *pdev)
>
> ddata->hpd_gpio = gpio;
>
> + mutex_init(&ddata->hpd_lock);
> +
> + r = devm_request_threaded_irq(&pdev->dev, gpiod_to_irq(ddata-
>hpd_gpio),

As the connector code can handle GPIO HPD thanks to patch 2/3, why does it
have to be duplicated here ? I agree that encoders should support reporting of
hotplug events when the HPD signal is connected to an encoder, but if it's
connected to a GPIO, it seems to me that it should be the sole responsibility
of the connector code to handle it.

> + NULL, tpd_hpd_isr,
> + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> + "tpd12s015 hpd", ddata);
> + if (r)
> + goto err_gpio;
> +
> dssdev = &ddata->dssdev;
> dssdev->ops.hdmi = &tpd_hdmi_ops;
> dssdev->dev = &pdev->dev;

--
Regards,

Laurent Pinchart