[PATCH 2/2] drm: bridge: icn6211: Add DSI lane count DT property parsing

[Robert Foss]

On Thu, 7 Apr 2022 at 20:56, Marek Vasut <marex at denx.de> wrote:
>
> The driver currently hard-codes DSI lane count to two, however the chip
> is capable of operating in 1..4 DSI lanes mode. Parse 'data-lanes' DT
> property and program the result into DSI_CTRL register.
>
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Jagan Teki <jagan at amarulasolutions.com>
> Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Cc: Maxime Ripard <maxime at cerno.tech>
> Cc: Robert Foss <robert.foss at linaro.org>
> Cc: Sam Ravnborg <sam at ravnborg.org>
> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> To: dri-devel at lists.freedesktop.org
> ---
>  drivers/gpu/drm/bridge/chipone-icn6211.c | 23 +++++++++++++++++++++--
>  1 file changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c
> index 6ce0633d4c089..e2b599a44275c 100644
> --- a/drivers/gpu/drm/bridge/chipone-icn6211.c
> +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c
> @@ -395,6 +395,11 @@ static void chipone_atomic_enable(struct drm_bridge *bridge,
>         /* dsi specific sequence */
>         chipone_writeb(icn, SYNC_EVENT_DLY, 0x80);
>         chipone_writeb(icn, HFP_MIN, hfp & 0xff);
> +
> +       /* DSI data lane count */
> +       chipone_writeb(icn, DSI_CTRL,
> +                   DSI_CTRL_UNKNOWN | DSI_CTRL_DSI_LANES(icn->dsi->lanes - 1));
> +
>         chipone_writeb(icn, MIPI_PD_CK_LANE, 0xa0);
>         chipone_writeb(icn, PLL_CTRL(12), 0xff);
>         chipone_writeb(icn, MIPI_PN_SWAP, 0x00);
> @@ -480,9 +485,23 @@ static void chipone_mode_set(struct drm_bridge *bridge,
>  static int chipone_dsi_attach(struct chipone *icn)
>  {
>         struct mipi_dsi_device *dsi = icn->dsi;
> -       int ret;
> +       struct device *dev = icn->dev;
> +       struct device_node *endpoint;
> +       int dsi_lanes, ret;
> +
> +       endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
> +       dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
> +       of_node_put(endpoint);
> +
> +       /*
> +        * If the 'data-lanes' property does not exist in DT or is invalid,
> +        * default to previously hard-coded behavior, which was 4 data lanes.
> +        */
> +       if (dsi_lanes >= 1 && dsi_lanes <= 4)
> +               icn->dsi->lanes = dsi_lanes;
> +       else
> +               icn->dsi->lanes = 4;
>
> -       dsi->lanes = 4;
>         dsi->format = MIPI_DSI_FMT_RGB888;
>         dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
>                           MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_NO_EOT_PACKET;

Reviewed-by: Robert Foss <robert.foss at linaro.org>

Fixed checkpatch --strict format warning & applied to drm-misc-next.

Rob.