On Thu, 7 Sep 2017 15:06:13 +0530 Archit Taneja architt@codeaurora.org wrote:
Hi,
On 08/31/2017 09:25 PM, Boris Brezillon wrote:
Add a driver for Cadence DPI -> DSI bridge.
This driver only support a subset of Cadence DSI bridge capabilities.
Here is a non-exhaustive list of missing features:
- burst mode
- dynamic configuration of the DPHY based on the
- support for additional input interfaces (SDI input)
Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com
Changes in v3:
- replace magic values by real timing calculation. The DPHY PLL clock is still hardcoded since we don't have a working DPHY block yet, and this is the piece of HW we need to dynamically configure the PLL rate based on the display refresh rate and the resolution.
- parse DSI devices represented with the OF-graph. This is needed to support DSI devices controlled through an external bus like I2C or SPI.
- use the DRM panel-bridge infrastructure to simplify the DRM panel logic
Changes in v2:
- rebase on v4.12-rc1 and adapt to driver to the drm_bridge API changes
- return the correct error when devm_clk_get(sysclk) fails
- add missing depends on OF and select DRM_PANEL in the Kconfig entry
drivers/gpu/drm/bridge/Kconfig | 9 + drivers/gpu/drm/bridge/Makefile | 1 + drivers/gpu/drm/bridge/cdns-dsi.c | 1090 +++++++++++++++++++++++++++++++++++++ 3 files changed, 1100 insertions(+) create mode 100644 drivers/gpu/drm/bridge/cdns-dsi.c
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index adf9ae0e0b7c..88c324b12e16 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -25,6 +25,15 @@ config DRM_ANALOGIX_ANX78XX the HDMI output of an application processor to MyDP or DisplayPort.
+config DRM_CDNS_DSI
- tristate "Cadence DPI/DSI bridge"
- select DRM_KMS_HELPER
- select DRM_MIPI_DSI
- select DRM_PANEL
- depends on OF
- help
Support Cadence DPI to DSI bridge.Maybe we can briefly mention here that it's a internal bridge/IP, and not an external chip?
Sure.
- config DRM_DUMB_VGA_DAC tristate "Dumb VGA DAC Bridge support" depends on OF
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile index defcf1e7ca1c..77b65e8ecf59 100644 --- a/drivers/gpu/drm/bridge/Makefile +++ b/drivers/gpu/drm/bridge/Makefile @@ -1,4 +1,5 @@ obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o +obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o obj-$(CONFIG_DRM_DUMB_VGA_DAC) += dumb-vga-dac.o obj-$(CONFIG_DRM_LVDS_ENCODER) += lvds-encoder.o obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o diff --git a/drivers/gpu/drm/bridge/cdns-dsi.c b/drivers/gpu/drm/bridge/cdns-dsi.c
<snip>
+static void cdns_dsi_bridge_disable(struct drm_bridge *bridge) +{
- struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
- struct cdns_dsi *dsi = input_to_dsi(input);
- u32 val;
- val = readl(dsi->regs + MCTL_MAIN_DATA_CTL);
- val &= ~(IF_VID_SELECT_MASK | IF_VID_MODE | VID_EN | HOST_EOT_GEN |
DISP_EOT_GEN);I see some truncation related sparse warnings here and a couple of other places when building against arm32. Those would be nice to fix.
I'll have a look.
+static int cdns_dsi_attach(struct mipi_dsi_host *host,
struct mipi_dsi_device *dev)+{
- struct cdns_dsi *dsi = to_cdns_dsi(host);
- struct cdns_dsi_output *output = &dsi->output;
- struct cdns_dsi_input *input = &dsi->input;
- struct drm_bridge *bridge;
- struct drm_panel *panel;
- struct device_node *np;
- int ret;
- /*
* We currently do not support connecting several DSI devices to the* same host. In order to support that we'd need the DRM bridge* framework to allow dynamic reconfiguration of the bridge chain.*/- if (output->dev)
return -EBUSY;- /* We do not support burst mode yet. */
- if (dev->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
return -ENOTSUPP;- /*
* The host <-> device link might be described using an OF-graph* representation, in this case we extract the device of_node from* this representation, otherwise we use dsidev->dev.of_node which* should have been filled by the core.*/- np = of_graph_get_remote_node(dsi->base.dev->of_node, DSI_OUTPUT_PORT,
dev->channel);- if (!np)
np = of_node_get(dev->dev.of_node); > +- panel = of_drm_find_panel(np);
- if (panel) {
bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DSI);- } else {
bridge = of_drm_find_bridge(dev->dev.of_node);if (!bridge)bridge = ERR_PTR(-EINVAL);- }
- of_node_put(np);
It would have been nice to use drm_of_find_panel_or_bridge() here, but I guess you couldn't use it because you have to handle both OF-graph based links, and children directly under the host DSI bus.
Yep.
Thanks for you review, and sorry for taking so long to reply.
Boris