Re: [PATCH v3 25/56] drm/omap: dsi: move TE GPIO handling into core

[Tomi Valkeinen <tomi.valkeinen@ti.com>]

On 09/11/2020 11:19, Laurent Pinchart wrote:
> Hi Tomi and Sebastian,
> 
> Thank you for the patch.
> 
> On Thu, Nov 05, 2020 at 02:03:02PM +0200, Tomi Valkeinen wrote:
>> From: Sebastian Reichel <sebastian.reichel@collabora.com>
>>
>> In preparation for removing custom DSS calls from the DSI
>> panel driver, this moves support for external tearing event
>> GPIOs into the DSI host driver. This way tearing events are
>> always handled in the core resulting in simplification of
>> the panel drivers.
>>
>> The TE GPIO acquisition follows works in the same way as the
>> exynos DSI implementation.
>>
>> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
>> ---
>>  .../gpu/drm/omapdrm/displays/panel-dsi-cm.c   | 101 +------------
>>  drivers/gpu/drm/omapdrm/dss/dsi.c             | 138 ++++++++++++++++--
>>  2 files changed, 133 insertions(+), 106 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c b/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c
>> index 8890ee2ba830..43f63b5a120b 100644
>> --- a/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c
>> +++ b/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c
>> @@ -54,7 +54,6 @@ struct panel_drv_data {
>>  
>>  	/* panel HW configuration from DT or platform data */
>>  	struct gpio_desc *reset_gpio;
>> -	struct gpio_desc *ext_te_gpio;
>>  
>>  	struct regulator_bulk_data supplies[DCS_REGULATOR_SUPPLY_NUM];
>>  
>> @@ -68,10 +67,6 @@ struct panel_drv_data {
>>  
>>  	bool te_enabled;
>>  
>> -	atomic_t do_update;
>> -
>> -	struct delayed_work te_timeout_work;
>> -
>>  	bool intro_printed;
>>  
>>  	struct workqueue_struct *workqueue;
>> @@ -83,8 +78,6 @@ struct panel_drv_data {
>>  
>>  #define to_panel_data(p) container_of(p, struct panel_drv_data, dssdev)
>>  
>> -static irqreturn_t dsicm_te_isr(int irq, void *data);
>> -static void dsicm_te_timeout_work_callback(struct work_struct *work);
>>  static int _dsicm_enable_te(struct panel_drv_data *ddata, bool enable);
>>  
>>  static int dsicm_panel_reset(struct panel_drv_data *ddata);
>> @@ -240,9 +233,6 @@ static int dsicm_enter_ulps(struct panel_drv_data *ddata)
>>  	if (r)
>>  		goto err;
>>  
>> -	if (ddata->ext_te_gpio)
>> -		disable_irq(gpiod_to_irq(ddata->ext_te_gpio));
>> -
>>  	src->ops->dsi.disable(src, false, true);
>>  
>>  	ddata->ulps_enabled = true;
>> @@ -271,15 +261,12 @@ static int dsicm_exit_ulps(struct panel_drv_data *ddata)
>>  	src->ops->enable(src);
>>  	ddata->dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
>>  
>> -	r = _dsicm_enable_te(ddata, true);
>> +	r = _dsicm_enable_te(ddata, ddata->te_enabled);
>>  	if (r) {
>>  		dev_err(&ddata->dsi->dev, "failed to re-enable TE");
>>  		goto err2;
>>  	}
>>  
>> -	if (ddata->ext_te_gpio)
>> -		enable_irq(gpiod_to_irq(ddata->ext_te_gpio));
>> -
>>  	dsicm_queue_ulps_work(ddata);
>>  
>>  	ddata->ulps_enabled = false;
>> @@ -290,11 +277,8 @@ static int dsicm_exit_ulps(struct panel_drv_data *ddata)
>>  	dev_err(&ddata->dsi->dev, "failed to exit ULPS");
>>  
>>  	r = dsicm_panel_reset(ddata);
>> -	if (!r) {
>> -		if (ddata->ext_te_gpio)
>> -			enable_irq(gpiod_to_irq(ddata->ext_te_gpio));
>> +	if (!r)
>>  		ddata->ulps_enabled = false;
>> -	}
>>  
>>  	dsicm_queue_ulps_work(ddata);
>>  
>> @@ -745,43 +729,6 @@ static void dsicm_framedone_cb(int err, void *data)
>>  	src->ops->dsi.bus_unlock(src);
>>  }
>>  
>> -static irqreturn_t dsicm_te_isr(int irq, void *data)
>> -{
>> -	struct panel_drv_data *ddata = data;
>> -	struct omap_dss_device *src = ddata->src;
>> -	int old;
>> -	int r;
>> -
>> -	old = atomic_cmpxchg(&ddata->do_update, 1, 0);
>> -
>> -	if (old) {
>> -		cancel_delayed_work(&ddata->te_timeout_work);
>> -
>> -		r = src->ops->dsi.update(src, ddata->dsi->channel, dsicm_framedone_cb,
>> -				ddata);
>> -		if (r)
>> -			goto err;
>> -	}
>> -
>> -	return IRQ_HANDLED;
>> -err:
>> -	dev_err(&ddata->dsi->dev, "start update failed\n");
>> -	src->ops->dsi.bus_unlock(src);
>> -	return IRQ_HANDLED;
>> -}
>> -
>> -static void dsicm_te_timeout_work_callback(struct work_struct *work)
>> -{
>> -	struct panel_drv_data *ddata = container_of(work, struct panel_drv_data,
>> -					te_timeout_work.work);
>> -	struct omap_dss_device *src = ddata->src;
>> -
>> -	dev_err(&ddata->dsi->dev, "TE not received for 250ms!\n");
>> -
>> -	atomic_set(&ddata->do_update, 0);
>> -	src->ops->dsi.bus_unlock(src);
>> -}
>> -
>>  static int dsicm_update(struct omap_dss_device *dssdev,
>>  				    u16 x, u16 y, u16 w, u16 h)
>>  {
>> @@ -809,16 +756,10 @@ static int dsicm_update(struct omap_dss_device *dssdev,
>>  	if (r)
>>  		goto err;
>>  
>> -	if (ddata->te_enabled && ddata->ext_te_gpio) {
>> -		schedule_delayed_work(&ddata->te_timeout_work,
>> -				msecs_to_jiffies(250));
>> -		atomic_set(&ddata->do_update, 1);
>> -	} else {
>> -		r = src->ops->dsi.update(src, ddata->dsi->channel, dsicm_framedone_cb,
>> -				ddata);
>> -		if (r)
>> -			goto err;
>> -	}
>> +	r = src->ops->dsi.update(src, ddata->dsi->channel, dsicm_framedone_cb,
>> +			ddata);
>> +	if (r)
>> +		goto err;
>>  
>>  	/* note: no bus_unlock here. unlock is src framedone_cb */
>>  	mutex_unlock(&ddata->lock);
>> @@ -840,8 +781,7 @@ static int _dsicm_enable_te(struct panel_drv_data *ddata, bool enable)
>>  	else
>>  		r = mipi_dsi_dcs_set_tear_off(dsi);
>>  
>> -	if (!ddata->ext_te_gpio)
>> -		src->ops->dsi.enable_te(src, enable);
>> +	src->ops->dsi.enable_te(src, enable);
>>  
>>  	/* possible panel bug */
>>  	msleep(100);
>> @@ -934,14 +874,6 @@ static int dsicm_probe_of(struct mipi_dsi_device *dsi)
>>  		return err;
>>  	}
>>  
>> -	ddata->ext_te_gpio = devm_gpiod_get_optional(&dsi->dev, "te",
>> -						     GPIOD_IN);
>> -	if (IS_ERR(ddata->ext_te_gpio)) {
>> -		err = PTR_ERR(ddata->ext_te_gpio);
>> -		dev_err(&dsi->dev, "TE gpio request failed: %d", err);
>> -		return err;
>> -	}
>> -
>>  	err = of_get_display_timing(node, "panel-timing", &timing);
>>  	if (!err) {
>>  		videomode_from_timing(&timing, &ddata->vm);
>> @@ -1024,25 +956,6 @@ static int dsicm_probe(struct mipi_dsi_device *dsi)
>>  
>>  	mutex_init(&ddata->lock);
>>  
>> -	atomic_set(&ddata->do_update, 0);
>> -
>> -	if (ddata->ext_te_gpio) {
>> -		r = devm_request_irq(dev, gpiod_to_irq(ddata->ext_te_gpio),
>> -				dsicm_te_isr,
>> -				IRQF_TRIGGER_RISING,
>> -				"taal vsync", ddata);
>> -
>> -		if (r) {
>> -			dev_err(dev, "IRQ request failed\n");
>> -			goto err_reg;
>> -		}
>> -
>> -		INIT_DEFERRABLE_WORK(&ddata->te_timeout_work,
>> -					dsicm_te_timeout_work_callback);
>> -
>> -		dev_dbg(dev, "Using GPIO TE\n");
>> -	}
>> -
>>  	ddata->workqueue = create_singlethread_workqueue("dsicm_wq");
>>  	if (!ddata->workqueue) {
>>  		r = -ENOMEM;
>> diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
>> index 003d26cead5a..921e7a1e1014 100644
>> --- a/drivers/gpu/drm/omapdrm/dss/dsi.c
>> +++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
>> @@ -14,7 +14,9 @@
>>  #include <linux/device.h>
>>  #include <linux/err.h>
>>  #include <linux/interrupt.h>
>> +#include <linux/irq.h>
>>  #include <linux/delay.h>
>> +#include <linux/gpio/consumer.h>
> 
> You could sort the headers while at it :-)

I'll do that after the series.

>>  #include <linux/mutex.h>
>>  #include <linux/module.h>
>>  #include <linux/semaphore.h>
>> @@ -368,6 +370,11 @@ struct dsi_data {
>>  	unsigned int update_bytes;
>>  #endif
>>  
>> +	/* external TE GPIO */
>> +	struct gpio_desc *te_gpio;
>> +	struct delayed_work te_timeout_work;
>> +	atomic_t do_ext_te_update;
>> +
>>  	bool te_enabled;
>>  	bool ulps_enabled;
>>  
>> @@ -3827,19 +3834,12 @@ static void dsi_framedone_irq_callback(void *data)
>>  	dsi_handle_framedone(dsi, 0);
>>  }
>>  
>> -static int dsi_update(struct omap_dss_device *dssdev, int channel,
>> -		void (*callback)(int, void *), void *data)
>> +static int _dsi_update(struct dsi_data *dsi)
>>  {
>> -	struct dsi_data *dsi = to_dsi_data(dssdev);
>>  	u16 dw, dh;
>>  
>>  	dsi_perf_mark_setup(dsi);
>>  
>> -	dsi->update_channel = channel;
>> -
>> -	dsi->framedone_callback = callback;
>> -	dsi->framedone_data = data;
>> -
>>  	dw = dsi->vm.hactive;
>>  	dh = dsi->vm.vactive;
>>  
>> @@ -3852,6 +3852,26 @@ static int dsi_update(struct omap_dss_device *dssdev, int channel,
>>  	return 0;
>>  }
>>  
>> +static int dsi_update(struct omap_dss_device *dssdev, int channel,
>> +		void (*callback)(int, void *), void *data)
>> +{
>> +	struct dsi_data *dsi = to_dsi_data(dssdev);
>> +
>> +	dsi->update_channel = channel;
>> +	dsi->framedone_callback = callback;
>> +	dsi->framedone_data = data;
>> +
>> +	if (dsi->te_enabled && dsi->te_gpio) {
>> +		schedule_delayed_work(&dsi->te_timeout_work,
>> +				      msecs_to_jiffies(250));
>> +		atomic_set(&dsi->do_ext_te_update, 1);
>> +	} else {
>> +		_dsi_update(dsi);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>>  /* Display funcs */
>>  
>>  static int dsi_configure_dispc_clocks(struct dsi_data *dsi)
>> @@ -4095,6 +4115,14 @@ static int dsi_enable_te(struct omap_dss_device *dssdev, bool enable)
>>  	struct dsi_data *dsi = to_dsi_data(dssdev);
>>  
>>  	dsi->te_enabled = enable;
>> +
>> +	if (dsi->te_gpio) {
>> +		if (enable)
>> +			enable_irq(gpiod_to_irq(dsi->te_gpio));
>> +		else
>> +			disable_irq(gpiod_to_irq(dsi->te_gpio));
>> +	}
>> +
>>  	return 0;
>>  }
>>  
>> @@ -4772,11 +4800,89 @@ static const struct omap_dss_device_ops dsi_ops = {
>>  	},
>>  };
>>  
>> +static irqreturn_t omap_dsi_te_irq_handler(int irq, void *dev_id)
>> +{
>> +	struct dsi_data *dsi = (struct dsi_data *)dev_id;
>> +	int old;
>> +
>> +	old = atomic_cmpxchg(&dsi->do_ext_te_update, 1, 0);
>> +	if (old) {
>> +		cancel_delayed_work(&dsi->te_timeout_work);
>> +		_dsi_update(dsi);
>> +	}
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static void omap_dsi_te_timeout_work_callback(struct work_struct *work)
>> +{
>> +	struct dsi_data *dsi = container_of(work, struct dsi_data,
>> +					te_timeout_work.work);
> 
> Strange indentation.
> 
>> +	int old;
>> +
>> +	old = atomic_cmpxchg(&dsi->do_ext_te_update, 1, 0);
>> +	if (old) {
>> +		dev_err(dsi->dev, "TE not received for 250ms!\n");
>> +		_dsi_update(dsi);
>> +	}
>> +}
>> +
>> +static int omap_dsi_register_te_irq(struct dsi_data *dsi,
>> +				    struct mipi_dsi_device *client)
>> +{
>> +	int err;
>> +	int te_irq;
>> +
>> +	dsi->te_gpio = gpiod_get_from_of_node(client->dev.of_node,
> 
> Could we call gpiod_get(&client->dev, "te", ...) instead ?

Yep.

>> +					      "te-gpios", 0, GPIOD_IN,
>> +					      "dsi-tearing-effect");
>> +	if (IS_ERR(dsi->te_gpio)) {
>> +		err = PTR_ERR(dsi->te_gpio);
>> +
>> +		if (err == -ENOENT) {
>> +			dsi->te_gpio = NULL;
>> +			return 0;
>> +		}
>> +
>> +		dev_err(dsi->dev, "Could not get TE gpio: %d\n", err);
>> +		return err;
>> +	}
>> +
>> +	te_irq = gpiod_to_irq(dsi->te_gpio);
> 
> Could this fail ?

Yes, I'll add error handling.

>> +	irq_set_status_flags(te_irq, IRQ_NOAUTOEN);
>> +
>> +	err = request_threaded_irq(te_irq, omap_dsi_te_irq_handler, NULL,
>> +				   IRQF_TRIGGER_RISING, "TE", dsi);
> 
> What's the reason to request a threaded IRQ instead of a regular IRQ if
> the threaded handler is NULL ?

Probably just a mistake. I'll change this to use the threaded handler.

>> +	if (err) {
>> +		dev_err(dsi->dev, "request irq failed with %d\n", err);
>> +		gpiod_put(dsi->te_gpio);
>> +		return err;
>> +	}
>> +
>> +	INIT_DEFERRABLE_WORK(&dsi->te_timeout_work,
>> +			     omap_dsi_te_timeout_work_callback);
>> +
>> +	dev_dbg(dsi->dev, "Using GPIO TE\n");
>> +
>> +	return 0;
>> +}
>> +
>> +static void omap_dsi_unregister_te_irq(struct dsi_data *dsi)
>> +{
>> +	if (dsi->te_gpio) {
>> +		free_irq(gpiod_to_irq(dsi->te_gpio), dsi);
> 
> You could store the IRQ number in dsi_data to avoid recomputing it.

Yep.

 Tomi

-- 
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki