Hi, On Tue, Jan 03, 2023 at 01:07:04PM -0600, Chris Morgan wrote: > From: Chris Morgan <macromorgan@xxxxxxxxxxx> > > Add helper function to find DSI host for devices where DSI panel is not > a minor of a DSI bus (such as the Samsung AMS495QA01 panel or the > official Raspberry Pi touchscreen display). > > Signed-off-by: Chris Morgan <macromorgan@xxxxxxxxxxx> > Signed-off-by: Maya Matuszczyk <maccraft123mc@xxxxxxxxx> > Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx> > --- > drivers/gpu/drm/drm_of.c | 62 ++++++++++++++++++++++++++++++++++++++++ > include/drm/drm_of.h | 11 +++++++ > 2 files changed, 73 insertions(+) > > diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c > index 7bbcb999bb75..7d89ac164069 100644 > --- a/drivers/gpu/drm/drm_of.c > +++ b/drivers/gpu/drm/drm_of.c > @@ -10,6 +10,7 @@ > #include <drm/drm_crtc.h> > #include <drm/drm_device.h> > #include <drm/drm_encoder.h> > +#include <drm/drm_mipi_dsi.h> > #include <drm/drm_of.h> > #include <drm/drm_panel.h> > > @@ -493,3 +494,64 @@ int drm_of_get_data_lanes_count_ep(const struct device_node *port, > return ret; > } > EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count_ep); > + > +/** > + * drm_of_get_dsi_bus - find the DSI bus for a given device > + * @dev: parent device of display (SPI, I2C) > + * @dsi_host: DSI host to be populated > + * @info: DSI device info to be updated with correct DSI node Why aren't we returning the dsi_host through an ERR_PTR? All the DRM accessors with get return the pointer directly, I'd rather stick to that. > + * Given a panel device parented to a non-DSI device, follow the > + * devicetree to find the correct DSI host node and populate the > + * dsi_host with the correct host and info with the correct node. I think we could make that a bit clearer using something like: Gets parent DSI bus for a DSI device controlled through a bus other than MIPI-DCS (SPI, I2C, etc.) using the Device Tree. > + * Returns zero if successful, -EPROBE_DEFER if the DSI host is > + * found but not available, or -ENODEV otherwise. > + */ > +int drm_of_get_dsi_bus(struct device *dev, > + struct mipi_dsi_host **dsi_host, > + struct mipi_dsi_device_info *info) The arguments are not aligned. Maxime
