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path: root/drivers/gpu/drm/rcar-du/rcar_lvds.h
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2023-05-29drm: Place Renesas drivers in a separate dirBiju Das
Create vendor specific renesas directory and move renesas drivers to that directory. Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> Acked-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
2023-03-25drm: rcar-du: lvds: Fix LVDS PLL disable on D3/E3Laurent Pinchart
On R-Car D3 and E3, the LVDS encoder provides the dot (pixel) clock to the DU, regardless of whether the LVDS output is used or not. When using the DPAD (RGB) output, the DU driver thus enables and disables the LVDS PLL manually, while when using the LVDS output, it lets the LVDS bridge driver handle the PLL configuration internally as part of the atomic enable and disable operations. This causes an issue when using the LVDS output. As bridges are disabled before CRTCs, the current implementation violates the enable/disable sequences documented in the hardware datasheet, which requires the dot clock to be enabled before the CRTC is started and disabled after it gets stopped. Fix the problem by enabling/disabling the LVDS PLL manually from the DU regardless of which output is used, and skipping the PLL handling in the LVDS bridge atomic enable and disable operations. This is however not enough. Disabling the LVDS encoder while leaving the PLL on still results in a vertical blanking wait timeout when disabling the DU. Investigation showed that the culprit is the LVEN bit. For an unclear reason, clearing the bit when disabling the LVDS encoder blocks vertical blanking interrupts. We thus have to delay disabling the whole LVDS encoder, not just disabling the PLL, until the DU is disabled. We could split the LVDS disable sequence by clearing the LVRES bit in the LVDS bridge atomic disable handler, and delaying the rest of the operations, in order to disable the LVDS output at bridge atomic disable time, before stopping the CRTC. This would make the code more complex, without a clear benefit, so keep the implementation simple(r). Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com>
2022-09-07drm: rcar-du: lvds: Rename pclk enable/disable functionsTomi Valkeinen
The DU driver uses the rcar_lvds_clk_enable() and rcar_lvds_clk_disable() functions enable or disable the pixel clock generated by the LVDS encoder, as it requires that clock for proper DU operation. Rename the functions by replacing "clk" with "pclk" to make it clearer that they related to the pixel clock. Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
2022-07-07drm: rcar-du: Drop file name from comment header blocksLaurent Pinchart
The comment blocks at the beginning of each file have a one-line summary description of the file that includes the file name. While the description is useful, the file name only creates opportunities for mistakes (as seen in rcar_du_vsp.c) without any added value. Drop it. Reported-by: Biju Das <biju.das.jz@bp.renesas.com> Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
2021-10-13drm: rcar-du: Don't create encoder for unconnected LVDS outputsLaurent Pinchart
On R-Car D3 and E3, the LVDS encoders provide the pixel clock to the DU, even when LVDS outputs are not used. For this reason, the rcar-lvds driver probes successfully on those platforms even if no further bridge or panel is connected to the LVDS output, in order to provide the rcar_lvds_clk_enable() and rcar_lvds_clk_disable() functions to the DU driver. If an LVDS output isn't connected, trying to create a DRM connector for the output will fail. Fix this by skipping connector creation in that case, and also skip creation of the DRM encoder as there's no point in an encoder without a connector. Fixes: e9e056949c92 ("drm: rcar-du: lvds: Convert to DRM panel bridge helper") Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> (cherry picked from commit 187502afe87a0fc96832056558978fa423920ee0) Signed-off-by: Dave Airlie <airlied@redhat.com>
2019-06-08drm: rcar-du: lvds: Add support for dual-link modeLaurent Pinchart
In dual-link mode the LVDS0 encoder transmits even-numbered pixels, and sends odd-numbered pixels to the LVDS1 encoder for transmission on a separate link. To implement support for this mode of operation, determine if the LVDS connection operates in dual-link mode by querying the next device in the pipeline, locate the companion encoder, and control it directly through its bridge operations. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org> Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org> Acked-by: Sam Ravnborg <sam@ravnborg.org> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
2019-02-08drm: rcar-du: lvds: Add API to enable/disable clock outputLaurent Pinchart
On the D3 and E3 platforms, the LVDS internal PLL supplies the pixel clock to the DU. This works automatically for LVDS outputs as the LVDS encoder is enabled through the bridge API, enabling the internal PLL and clock output. However, when using the DU DPAD output with the LVDS outputs turned off, the LVDS PLL needs to be controlled manually. Add an API to do so, to be called by the DU driver. The drivers/gpu/drm/rcar-du/ directory has to be treated as obj-y unconditionally, as the LVDS driver could be built-in while the DU driver is compiled as a module. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>