On Thu, Apr 24, 2025 at 05:07:41PM +0200, Kory Maincent wrote:
> Enable support for two-lane configuration which is done by setting the
> LANSEL_SW_EN and LANSEL_SW bits in the Pad Control register.
>
> Use the data-lanes device tree parameter to configure the number of lanes.
> The default configuration remains set to four lanes.
>
> Signed-off-by: Kory Maincent <kory.mainc...@bootlin.com>
> ---
>
> Change in v2:
> - Read the data-lanes parameter from the port endpoint and use
> drm_of_get_data_lanes_count instead of of_property_read_u32.
> ---
> drivers/gpu/drm/panel/panel-ilitek-ili9881c.c | 33
> +++++++++++++++++++++++++--
> 1 file changed, 31 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c
> b/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c
> index
> 28cd7560e5db1d5734b10babdb4e4e553c6e07d0..2e38dea28336f445cb6a074dbbec006f0659287a
> 100644
> --- a/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c
> +++ b/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c
> @@ -16,6 +16,7 @@
>
> #include <drm/drm_mipi_dsi.h>
> #include <drm/drm_modes.h>
> +#include <drm/drm_of.h>
> #include <drm/drm_panel.h>
>
> #include <video/mipi_display.h>
> @@ -1263,6 +1264,21 @@ static int ili9881c_send_cmd_data(struct ili9881c
> *ctx, u8 cmd, u8 data)
> return 0;
> }
>
> +static int ili9881c_set_lanes_cfg(struct ili9881c *ctx)
> +{
> + int ret;
> +
> + if (ctx->dsi->lanes != 2)
> + /* Nothing to do */
> + return 0;
> +
> + ret = ili9881c_switch_page(ctx, 1);
> + if (ret)
> + return ret;
> +
> + return ili9881c_send_cmd_data(ctx, 0xB7, 0x3);
> +}
> +
> static int ili9881c_prepare(struct drm_panel *panel)
> {
> struct ili9881c *ctx = panel_to_ili9881c(panel);
> @@ -1295,6 +1311,10 @@ static int ili9881c_prepare(struct drm_panel *panel)
> return ret;
> }
>
> + ret = ili9881c_set_lanes_cfg(ctx);
> + if (ret)
> + return ret;
> +
> ret = ili9881c_switch_page(ctx, 0);
> if (ret)
> return ret;
> @@ -1503,8 +1523,9 @@ static const struct drm_panel_funcs ili9881c_funcs = {
>
> static int ili9881c_dsi_probe(struct mipi_dsi_device *dsi)
> {
> + struct device_node *endpoint;
> struct ili9881c *ctx;
> - int ret;
> + int ret, lanes;
>
> ctx = devm_kzalloc(&dsi->dev, sizeof(*ctx), GFP_KERNEL);
> if (!ctx)
> @@ -1545,11 +1566,19 @@ static int ili9881c_dsi_probe(struct mipi_dsi_device
> *dsi)
> if (ret)
> return ret;
>
> + endpoint = of_graph_get_endpoint_by_regs(dsi->dev.of_node, -1, -1);
> + lanes = drm_of_get_data_lanes_count(endpoint, 2, 4);
> + of_node_put(endpoint);
I think you can use drm_of_get_data_lanes_count_ep() here.
> + if (lanes == -EINVAL)
> + lanes = 4;
> + else if (lanes < 0)
> + return lanes;
> +
> drm_panel_add(&ctx->panel);
>
> dsi->mode_flags = ctx->desc->mode_flags;
> dsi->format = MIPI_DSI_FMT_RGB888;
> - dsi->lanes = 4;
> + dsi->lanes = lanes;
>
> return mipi_dsi_attach(dsi);
> }
>
> --
> 2.34.1
>
--
With best wishes
Dmitry
