Hi Paul.
On Mon, Jul 27, 2020 at 06:46:09PM +0200, Paul Cercueil wrote:
> The current MIPI DSI framework can very well be used to support MIPI DBI
> panels. In order to add support for the various bus types supported by
> DBI, the DRM panel drivers should specify the bus type they will use,
> and the DSI host drivers should specify the bus types they are
> compatible with.
>
> The DSI host driver can then use the information provided by the DBI/DSI
> device driver, such as the bus type and the number of lanes, to
> configure its hardware properly.
>
> Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/drm_mipi_dsi.c | 9 +++++++++
> include/drm/drm_mipi_dsi.h | 12 ++++++++++++
> 2 files changed, 21 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
> index 5dd475e82995..11ef885de765 100644
> --- a/drivers/gpu/drm/drm_mipi_dsi.c
> +++ b/drivers/gpu/drm/drm_mipi_dsi.c
> @@ -281,6 +281,9 @@ int mipi_dsi_host_register(struct mipi_dsi_host *host)
> {
> struct device_node *node;
>
> + if (WARN_ON_ONCE(!host->bus_types))
> + host->bus_types = MIPI_DEVICE_TYPE_DSI;
> +
So all 14 users need to specify bus_types.
Seems doable.
> for_each_available_child_of_node(host->dev->of_node, node) {
> /* skip nodes without reg property */
> if (!of_find_property(node, "reg", NULL))
> @@ -323,6 +326,12 @@ int mipi_dsi_attach(struct mipi_dsi_device *dsi)
> {
> const struct mipi_dsi_host_ops *ops = dsi->host->ops;
>
> + if (WARN_ON_ONCE(!dsi->bus_type))
> + dsi->bus_type = MIPI_DEVICE_TYPE_DSI;
We have ~50 users of mipi_dsi_attach() - doable. But a bit more work.
> +
> + if (!(dsi->bus_type & dsi->host->bus_types))
> + return -EINVAL;
> +
> if (!ops || !ops->attach)
> return -ENOSYS;
>
> diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
> index 360e6377e84b..65d2961fc054 100644
> --- a/include/drm/drm_mipi_dsi.h
> +++ b/include/drm/drm_mipi_dsi.h
> @@ -63,6 +63,14 @@ struct mipi_dsi_packet {
> int mipi_dsi_create_packet(struct mipi_dsi_packet *packet,
> const struct mipi_dsi_msg *msg);
>
> +/* MIPI bus types */
If you define this as an enum then kernel-doc syntax will be picked up.
See for example: enum drm_driver_feature
> +#define MIPI_DEVICE_TYPE_DSI BIT(0)
> +#define MIPI_DEVICE_TYPE_DBI_SPI_MODE1 BIT(1)
> +#define MIPI_DEVICE_TYPE_DBI_SPI_MODE2 BIT(2)
> +#define MIPI_DEVICE_TYPE_DBI_SPI_MODE3 BIT(3)
> +#define MIPI_DEVICE_TYPE_DBI_M6800 BIT(4)
> +#define MIPI_DEVICE_TYPE_DBI_I8080 BIT(5)
> +
> /**
> * struct mipi_dsi_host_ops - DSI bus operations
> * @attach: attach DSI device to DSI host
> @@ -94,11 +102,13 @@ struct mipi_dsi_host_ops {
> * struct mipi_dsi_host - DSI host device
> * @dev: driver model device node for this DSI host
> * @ops: DSI host operations
> + * @bus_types: Bitmask of supported MIPI bus types
Please add some kind of reference to MIPI_DEVICE_TYPE_* - so the reader
knows for sure this is the bits used here.
> * @list: list management
> */
> struct mipi_dsi_host {
> struct device *dev;
> const struct mipi_dsi_host_ops *ops;
> + unsigned int bus_types;
Use u32. Shorter and we know this is 32 bits wide.
> struct list_head list;
> };
>
> @@ -162,6 +172,7 @@ struct mipi_dsi_device_info {
> * @host: DSI host for this peripheral
> * @dev: driver model device node for this peripheral
> * @name: DSI peripheral chip type
> + * @bus_type: MIPI bus type (MIPI_DEVICE_TYPE_DSI/...)
> * @channel: virtual channel assigned to the peripheral
> * @format: pixel format for video mode
> * @lanes: number of active data lanes
> @@ -178,6 +189,7 @@ struct mipi_dsi_device {
> struct device dev;
>
> char name[DSI_DEV_NAME_SIZE];
> + unsigned int bus_type;
Use u32.
> unsigned int channel;
> unsigned int lanes;
> enum mipi_dsi_pixel_format format;
> --
> 2.27.0
