Re: [PATCH v3 30/56] drm/omap: dsi: move panel refresh function to host

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Tomi,

On Wed, Nov 11, 2020 at 05:34:52PM +0200, Tomi Valkeinen wrote:
> On 09/11/2020 12:10, Laurent Pinchart wrote:
> > On Thu, Nov 05, 2020 at 02:03:07PM +0200, Tomi Valkeinen wrote:
> >> From: Sebastian Reichel <sebastian.reichel@collabora.com>
> >>
> >> This moves the panel refresh/update function from the panel
> >> driver into the DSI host driver to prepare for common drm_panel
> >> support.
> >>
> >> 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   |  68 ------------
> >>  drivers/gpu/drm/omapdrm/dss/dsi.c             | 101 ++++++++++++++++--
> >>  drivers/gpu/drm/omapdrm/dss/omapdss.h         |  13 +--
> >>  drivers/gpu/drm/omapdrm/omap_crtc.c           |  11 +-
> >>  4 files changed, 97 insertions(+), 96 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c b/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c
> >> index 030a8fa140db..1582960f9e90 100644
> >> --- a/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c
> >> +++ b/drivers/gpu/drm/omapdrm/displays/panel-dsi-cm.c
> >> @@ -177,27 +177,6 @@ static int dsicm_get_id(struct panel_drv_data *ddata, u8 *id1, u8 *id2, u8 *id3)
> >>  	return 0;
> >>  }
> >>  
> >> -static int dsicm_set_update_window(struct panel_drv_data *ddata,
> >> -		u16 x, u16 y, u16 w, u16 h)
> >> -{
> >> -	struct mipi_dsi_device *dsi = ddata->dsi;
> >> -	int r;
> >> -	u16 x1 = x;
> >> -	u16 x2 = x + w - 1;
> >> -	u16 y1 = y;
> >> -	u16 y2 = y + h - 1;
> >> -
> >> -	r = mipi_dsi_dcs_set_column_address(dsi, x1, x2);
> >> -	if (r < 0)
> >> -		return r;
> >> -
> >> -	r = mipi_dsi_dcs_set_page_address(dsi, y1, y2);
> >> -	if (r < 0)
> >> -		return r;
> >> -
> >> -	return 0;
> >> -}
> >> -
> > 
> > I can't tell whether this is common to all command-mode panels, or if
> > there could be a need for panel-specific update procedures, so I can't
> > really ack this patch.
> 
> I can't say either, but all the command mode panels I know need and support this. And, afaik, we
> have only the single cmd mode panel driver which we add in this series.

Now that I think about it again, isn't it a layering violation ?
Shouldn't the DSI host handle DSI commands transfers, with the panel
driver taking care of specific DSI commands ?

If keeping this code in the panel driver causes lots of rebase conflicts
I'm fine fixing this on top, but it looks like it belongs to the panel
driver.

> >>  static int dsicm_bl_update_status(struct backlight_device *dev)
> >>  {
> >>  	struct panel_drv_data *ddata = dev_get_drvdata(&dev->dev);
> >> @@ -470,48 +449,6 @@ static void dsicm_disable(struct omap_dss_device *dssdev)
> >>  	mutex_unlock(&ddata->lock);
> >>  }
> >>  
> >> -static void dsicm_framedone_cb(int err, void *data)
> >> -{
> >> -	struct panel_drv_data *ddata = data;
> >> -
> >> -	dev_dbg(&ddata->dsi->dev, "framedone, err %d\n", err);
> >> -	mutex_unlock(&ddata->lock);
> >> -}
> >> -
> >> -static int dsicm_update(struct omap_dss_device *dssdev,
> >> -				    u16 x, u16 y, u16 w, u16 h)
> >> -{
> >> -	struct panel_drv_data *ddata = to_panel_data(dssdev);
> >> -	struct omap_dss_device *src = ddata->src;
> >> -	int r;
> >> -
> >> -	dev_dbg(&ddata->dsi->dev, "update %d, %d, %d x %d\n", x, y, w, h);
> >> -
> >> -	mutex_lock(&ddata->lock);
> >> -
> >> -	if (!ddata->enabled) {
> >> -		r = 0;
> >> -		goto err;
> >> -	}
> >> -
> >> -	/* XXX no need to send this every frame, but dsi break if not done */
> >> -	r = dsicm_set_update_window(ddata, 0, 0, ddata->vm.hactive,
> >> -				    ddata->vm.vactive);
> >> -	if (r)
> >> -		goto err;
> >> -
> >> -	r = src->ops->dsi.update(src, ddata->dsi->channel, dsicm_framedone_cb,
> >> -			ddata);
> >> -	if (r)
> >> -		goto err;
> >> -
> >> -	/* note: no unlock here. unlock is src framedone_cb */
> >> -	return 0;
> >> -err:
> >> -	mutex_unlock(&ddata->lock);
> >> -	return r;
> >> -}
> >> -
> >>  static int _dsicm_enable_te(struct panel_drv_data *ddata, bool enable)
> >>  {
> >>  	struct mipi_dsi_device *dsi = ddata->dsi;
> >> @@ -572,10 +509,6 @@ static const struct omap_dss_device_ops dsicm_ops = {
> >>  	.check_timings	= dsicm_check_timings,
> >>  };
> >>  
> >> -static const struct omap_dss_driver dsicm_dss_driver = {
> >> -	.update		= dsicm_update,
> >> -};
> >> -
> >>  static int dsicm_probe_of(struct mipi_dsi_device *dsi)
> >>  {
> >>  	struct device_node *node = dsi->dev.of_node;
> >> @@ -658,7 +591,6 @@ static int dsicm_probe(struct mipi_dsi_device *dsi)
> >>  	dssdev = &ddata->dssdev;
> >>  	dssdev->dev = dev;
> >>  	dssdev->ops = &dsicm_ops;
> >> -	dssdev->driver = &dsicm_dss_driver;
> >>  	dssdev->type = OMAP_DISPLAY_TYPE_DSI;
> >>  	dssdev->display = true;
> >>  	dssdev->owner = THIS_MODULE;
> >> diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
> >> index 0f264654792d..0aa0d21cf896 100644
> >> --- a/drivers/gpu/drm/omapdrm/dss/dsi.c
> >> +++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
> >> @@ -214,6 +214,9 @@ static void dsi_display_uninit_dispc(struct dsi_data *dsi);
> >>  
> >>  static int dsi_vc_send_null(struct dsi_data *dsi, int channel);
> >>  
> >> +static ssize_t _omap_dsi_host_transfer(struct dsi_data *dsi,
> >> +				       const struct mipi_dsi_msg *msg);
> >> +
> >>  /* DSI PLL HSDIV indices */
> >>  #define HSDIV_DISPC	0
> >>  #define HSDIV_DSI	1
> >> @@ -383,9 +386,6 @@ struct dsi_data {
> >>  
> >>  	struct delayed_work ulps_work;
> >>  
> >> -	void (*framedone_callback)(int, void *);
> >> -	void *framedone_data;
> >> -
> >>  	struct delayed_work framedone_timeout_work;
> >>  
> >>  #ifdef DSI_CATCH_MISSING_TE
> >> @@ -3802,8 +3802,6 @@ static void dsi_handle_framedone(struct dsi_data *dsi, int error)
> >>  	dsi_set_ulps_auto(dsi, true);
> >>  	dsi_bus_unlock(dsi);
> >>  
> >> -	dsi->framedone_callback(error, dsi->framedone_data);
> >> -
> >>  	if (!error)
> >>  		dsi_perf_show(dsi, "DISPC");
> >>  }
> >> @@ -3835,6 +3833,8 @@ static void dsi_framedone_irq_callback(void *data)
> >>  
> >>  	cancel_delayed_work(&dsi->framedone_timeout_work);
> >>  
> >> +	DSSDBG("Framedone received!\n");
> >> +
> >>  	dsi_handle_framedone(dsi, 0);
> >>  }
> >>  
> >> @@ -3856,17 +3856,69 @@ static int _dsi_update(struct dsi_data *dsi)
> >>  	return 0;
> >>  }
> >>  
> >> -static int dsi_update(struct omap_dss_device *dssdev, int channel,
> >> -		void (*callback)(int, void *), void *data)
> >> +static int _dsi_update_window(struct dsi_data *dsi, int channel,
> >> +			      int x, int y, int w, int h)
> >> +{
> >> +	int x1 = x, x2 = (x + w - 1);
> >> +	int y1 = y, y2 = (y + h - 1);
> >> +	u8 payloadX[5] = { MIPI_DCS_SET_COLUMN_ADDRESS,
> >> +			   x1 >> 8, x1 & 0xff, x2 >> 8, x2 & 0xff };
> >> +	u8 payloadY[5] = { MIPI_DCS_SET_PAGE_ADDRESS,
> >> +			   y1 >> 8, y1 & 0xff, y2 >> 8, y2 & 0xff };
> >> +	struct mipi_dsi_msg msgX = { 0 }, msgY = { 0 };
> >> +	int ret;
> >> +
> >> +	WARN_ON(!dsi_bus_is_locked(dsi));
> >> +
> >> +	msgX.type = MIPI_DSI_DCS_LONG_WRITE;
> >> +	msgX.channel = channel;
> >> +	msgX.tx_buf = payloadX;
> >> +	msgX.tx_len = sizeof(payloadX);
> >> +
> >> +	msgY.type = MIPI_DSI_DCS_LONG_WRITE;
> >> +	msgY.channel = channel;
> >> +	msgY.tx_buf = payloadY;
> >> +	msgY.tx_len = sizeof(payloadY);
> >> +
> >> +	ret = _omap_dsi_host_transfer(dsi, &msgX);
> >> +	if (ret != 0)
> >> +		return ret;
> >> +
> >> +	return _omap_dsi_host_transfer(dsi, &msgY);
> >> +}
> >> +
> >> +static int dsi_update_channel(struct omap_dss_device *dssdev, int channel)
> >>  {
> >>  	struct dsi_data *dsi = to_dsi_data(dssdev);
> >> +	int r;
> >> +
> >> +	if (channel > 3)
> >> +		return -EINVAL;
> >>  
> >>  	dsi_bus_lock(dsi);
> >> +
> >> +	if (!dsi->vc[channel].dest) {
> >> +		r = -ENODEV;
> >> +		goto err;
> >> +	}
> >> +
> >> +	if (dsi->vm.hactive == 0 || dsi->vm.vactive == 0) {
> >> +		r = -EINVAL;
> >> +		goto err;
> >> +	}
> >> +
> >> +	DSSDBG("dsi_update_channel: %d", channel);
> >> +
> >>  	dsi_set_ulps_auto(dsi, false);
> >>  
> >> +	r = _dsi_update_window(dsi, channel, 0, 0, dsi->vm.hactive,
> >> +			       dsi->vm.vactive);
> >> +	if (r < 0) {
> >> +		DSSWARN("window update error: %d\n", r);
> >> +		goto err;
> >> +	}
> >> +
> >>  	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,
> >> @@ -3877,6 +3929,24 @@ static int dsi_update(struct omap_dss_device *dssdev, int channel,
> >>  	}
> >>  
> >>  	return 0;
> >> +
> >> +err:
> >> +	dsi_set_ulps_auto(dsi, true);
> >> +	dsi_bus_unlock(dsi);
> >> +	return r;
> >> +}
> >> +
> >> +static int dsi_update_all(struct omap_dss_device *dssdev)
> >> +{
> >> +	int i, r;
> > 
> > i should be unsigned as it's never negative.
> > 
> >> +
> >> +	for (i = 0; i < 4; i++) {
> >> +		r = dsi_update_channel(dssdev, i);
> >> +		if (r != -ENODEV)
> >> +			return r;
> >> +	}
> >> +
> >> +	return r;
> >>  }
> >>  
> >>  /* Display funcs */
> >> @@ -4095,7 +4165,9 @@ static void dsi_display_enable(struct omap_dss_device *dssdev)
> >>  {
> >>  	struct dsi_data *dsi = to_dsi_data(dssdev);
> >>  	DSSDBG("dsi_display_enable\n");
> >> +	dsi_bus_lock(dsi);
> > 
> > Why is the lock needed here now ? Should it be part of a previous patch
> > ? Or, if I'm missing something, should the commit message explain this ?
> > Same for the other locations below.
> 
> Yes, the locking should've been done in earlier patch. I moved them.

-- 
Regards,

Laurent Pinchart