Re: [PATCH v2 7/8] drm/bridge/synopsys: dsi: add dual-dsi support

Hi Heiko, Thank you for your patch,

On 06/18/2018 12:28 PM, Heiko Stuebner wrote:

From: Nickey Yang nickey.yang@rock-chips.com

Allow to also drive a slave dw-mipi-dsi controller in a dual-dsi setup. This will require additional implementation-specific code to look up the slave instance and do specific setup. Also will probably need code in the specific crtcs as dual-dsi does not equal two separate dsi outputs.

To activate, the implementation-specific code should set the slave using dw_mipi_dsi_set_slave() before calling __dw_mipi_dsi_bind().

v2:

• expect real interface number of lanes
• keep links to both master and slave

Signed-off-by: Nickey Yang nickey.yang@rock-chips.com Signed-off-by: Heiko Stuebner heiko@sntech.de

---

drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 93 +++++++++++++++++-- include/drm/bridge/dw_mipi_dsi.h | 1 + 2 files changed, 86 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c index bd503f000ed5..6a345d1dde25 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c @@ -230,9 +230,20 @@ struct dw_mipi_dsi { u32 format; unsigned long mode_flags;

• struct dw_mipi_dsi *master; /* dual-dsi master ptr */
• struct dw_mipi_dsi *slave; /* dual-dsi slave ptr */
• const struct dw_mipi_dsi_plat_data *plat_data; };

+/*

• • Check if either a link to a master or slave is present
• */

+static inline bool dw_mipi_is_dual_mode(struct dw_mipi_dsi *dsi) +{

• return dsi->slave || dsi->master;

+}

• /*
  • The controller should generate 2 frames before
  • preparing the peripheral.

@@ -273,18 +284,26 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host, struct drm_bridge *bridge; struct drm_panel *panel; int ret;

• int lanes = device->lanes;

I do not see a big interest here in adding the new var "lanes", I suggest to remove it or wait for more comments (not a strong opposition on my side:) just a preference).

• if (device->lanes > dsi->plat_data->max_data_lanes) {

• if (lanes > dsi->plat_data->max_data_lanes) { dev_err(dsi->dev, "the number of data lanes(%u) is too many\n", device->lanes);

please use "lanes" has you have created it ;-) or keep it as it is if you decide to remove the var lanes :)

return -EINVAL;

}

• dsi->lanes = device->lanes;

• dsi->lanes = lanes; dsi->channel = device->channel; dsi->format = device->format; dsi->mode_flags = device->mode_flags;

• if (dsi->slave) {

• dsi->slave->lanes = dsi->lanes;
  

• dsi->slave->channel = dsi->channel;
  

• dsi->slave->format = dsi->format;
  

• dsi->slave->mode_flags = dsi->mode_flags;
  

• }

• ret = drm_of_find_panel_or_bridge(host->dev->of_node, 1, 0, &panel, &bridge); if (ret)

@@ -441,10 +460,17 @@ static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host, }

dw_mipi_message_config(dsi, msg);

• if (dsi->slave)

• dw_mipi_message_config(dsi->slave, msg);
  
  

  ret = dw_mipi_dsi_write(dsi, &packet); if (ret) return ret;

• if (dsi->slave) {

• ret = dw_mipi_dsi_write(dsi->slave, &packet);
  

• if (ret)
  

• 	return ret;
  

• }

  if (msg->rx_buf && msg->rx_len) { ret = dw_mipi_dsi_read(dsi, msg);

@@ -583,7 +609,15 @@ static void dw_mipi_dsi_video_packet_config(struct dw_mipi_dsi *dsi, * DSI_VNPCR.NPSIZE... especially because this driver supports * non-burst video modes, see dw_mipi_dsi_video_mode_config()... */

• dsi_write(dsi, DSI_VID_PKT_SIZE, VID_PKT_SIZE(mode->hdisplay));

• int pkt_size;

I do not see any interest in adding this pkt_size, you can directly do the dsi_write (below) and remove minimum 4 lines in your patch then ... just my opinion : )

• if (dw_mipi_is_dual_mode(dsi))

• pkt_size = VID_PKT_SIZE(mode->hdisplay / 2);
  

• else

• pkt_size = VID_PKT_SIZE(mode->hdisplay);
  

• dsi_write(dsi, DSI_VID_PKT_SIZE, pkt_size); }

  static void dw_mipi_dsi_command_mode_config(struct dw_mipi_dsi *dsi)

@@ -756,23 +790,39 @@ static void dw_mipi_dsi_bridge_post_disable(struct drm_bridge *bridge) dsi->panel_bridge->funcs->post_disable(dsi->panel_bridge);

dw_mipi_dsi_disable(dsi);

Maybe you should move dw_mipi_dsi_disable(dsi) call after the if (dsi->slave)...

• if (dsi->slave) {

• dw_mipi_dsi_disable(dsi->slave);
  

• clk_disable_unprepare(dsi->slave->pclk);
  

• pm_runtime_put(dsi->slave->dev);
  

• }
• clk_disable_unprepare(dsi->pclk); pm_runtime_put(dsi->dev); }

-static void dw_mipi_dsi_bridge_mode_set(struct drm_bridge *bridge,

• 			struct drm_display_mode *mode,
  

• 			struct drm_display_mode *adjusted_mode)
  

+static unsigned int dw_mipi_dsi_get_lanes(struct dw_mipi_dsi *dsi) +{

• if (dsi->master)

• return dsi->master->lanes + dsi->lanes;
  

• if (dsi->slave)

• return dsi->lanes + dsi->slave->lanes;
  

maybe a short explanation for master, slave and single-dsi 3 cases could be nice here

• return dsi->lanes;

+}

+static void dw_mipi_dsi_mode_set(struct dw_mipi_dsi *dsi,

• 		struct drm_display_mode *adjusted_mode)
  

  {

• struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge); const struct dw_mipi_dsi_phy_ops *phy_ops = dsi->plat_data->phy_ops; void *priv_data = dsi->plat_data->priv_data; int ret;

• u32 lanes = dw_mipi_dsi_get_lanes(dsi);

  clk_prepare_enable(dsi->pclk);

  ret = phy_ops->get_lane_mbps(priv_data, adjusted_mode, dsi->mode_flags,

• 		     dsi->lanes, dsi->format, &dsi->lane_mbps);
  

• 		     lanes, dsi->format, &dsi->lane_mbps);
  

  if (ret) DRM_DEBUG_DRIVER("Phy get_lane_mbps() failed\n");

@@ -804,12 +854,25 @@ static void dw_mipi_dsi_bridge_mode_set(struct drm_bridge *bridge, dw_mipi_dsi_set_mode(dsi, 0); }

+static void dw_mipi_dsi_bridge_mode_set(struct drm_bridge *bridge,

• 			struct drm_display_mode *mode,
  

• 			struct drm_display_mode *adjusted_mode)
  

+{

• struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
• dw_mipi_dsi_mode_set(dsi, adjusted_mode);
• if (dsi->slave)

• dw_mipi_dsi_mode_set(dsi->slave, adjusted_mode);
  

+}

• static void dw_mipi_dsi_bridge_enable(struct drm_bridge *bridge) { struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);

  /* Switch to video mode for panel-bridge enable & panel enable */ dw_mipi_dsi_set_mode(dsi, MIPI_DSI_MODE_VIDEO);

• if (dsi->slave)

• dw_mipi_dsi_set_mode(dsi->slave, MIPI_DSI_MODE_VIDEO);
  

  }

  static enum drm_mode_status

@@ -949,6 +1012,20 @@ static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi) pm_runtime_disable(dsi->dev); }

+void dw_mipi_dsi_set_slave(struct dw_mipi_dsi *dsi, struct dw_mipi_dsi *slave) +{

• /* introduce controllers to each other */
• dsi->slave = slave;
• dsi->slave->master = dsi;
• /* migrate settings for already attached displays */
• dsi->slave->lanes = dsi->lanes;
• dsi->slave->channel = dsi->channel;
• dsi->slave->format = dsi->format;
• dsi->slave->mode_flags = dsi->mode_flags;

I though it has been done earlier in dw_mipi_dsi_host_attach() function?

+} +EXPORT_SYMBOL_GPL(dw_mipi_dsi_set_slave);

• /*
  • Probe/remove API, used from platforms based on the DRM bridge API.
  */

diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h index 6d7f8eb5d9f2..5fd997cdf281 100644 --- a/include/drm/bridge/dw_mipi_dsi.h +++ b/include/drm/bridge/dw_mipi_dsi.h @@ -37,5 +37,6 @@ struct dw_mipi_dsi *dw_mipi_dsi_probe(struct platform_device *pdev, void dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi); int dw_mipi_dsi_bind(struct dw_mipi_dsi *dsi, struct drm_encoder *encoder); void dw_mipi_dsi_unbind(struct dw_mipi_dsi *dsi); +void dw_mipi_dsi_set_slave(struct dw_mipi_dsi *dsi, struct dw_mipi_dsi *slave);

Tested-by: Philippe Cornu philippe.cornu@st.com (only on stm32 with single dsi so dual-dsi has not been tested)

I wait for more comments & (minor) updates before giving my reviewed-by but you are close to have it : )

many thanks, Philippe :-)

#endif /* __DW_MIPI_DSI__ */