From a408aaef0709c40f4daa53a18c0e1a2386e02df7 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Mon, 22 Mar 2021 02:32:29 +0200 Subject: linux: mm: Move max VGA dot clock validation from Abandoned to New The ADV7123 VGA DAC has an upper pixel clock frequency limit. It may not match the values set in the device tree in relevant BSP commits, but it still has to be taken into account. Signed-off-by: Laurent Pinchart --- .../bsp41x_simple-bridge-Validate-pixel-clock.yaml | 25 ++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 projects/linux/mm/bsp41x_simple-bridge-Validate-pixel-clock.yaml (limited to 'projects/linux/mm/bsp41x_simple-bridge-Validate-pixel-clock.yaml') diff --git a/projects/linux/mm/bsp41x_simple-bridge-Validate-pixel-clock.yaml b/projects/linux/mm/bsp41x_simple-bridge-Validate-pixel-clock.yaml new file mode 100644 index 0000000..845c390 --- /dev/null +++ b/projects/linux/mm/bsp41x_simple-bridge-Validate-pixel-clock.yaml @@ -0,0 +1,25 @@ +title: "BSP 4.1.x upport: simple-bridge: Validate pixel clock" +team: MM +key: ed367c5b-5cf5-4f6a-9382-186ef72c2bbe +status: New + +bsp41x: + - ae5ed0b2888c3c084849e3b1b77001c4b3519f5d # drm/bridge: dumb-vga-dac: Add dot clock valid check + - fccc46cf75fd45b867c8c8501c526a92efc4d49b # arm64: dts: r8a77995-draak: Set max dot clock for vga + - 64ee34a191cefc9fd10042f785996c811c336992 # arm64: dts: r8a77990-ebisu: Set max dot clock for vga + - a117af5977b652da0abece0b1a17049db4a76d09 # arm64: dts: salvator-common: Set max dot clock for vga + +comments: + - The ADV7123 VGA DAC used on the Draak, Ebisu and Salvator-X boards has a + pixel clock rate limit of 140MHz. The simple-bridge driver should implement + a .mode_valid() operation to reject modes that require a too high clock + frequency. + + However, the ADV7123 comes in multiple variants, with different frequency + limits. Matching on the compatible string to get the frequency limit is an + option, but would lead to a proliferation of compatible strings. A + vendor-specific DT property may be a better solution. + + - The limits set in the BSP's DT sources doesn't match the AD7123's limit. + Those limits must not be copied blindly, more information is needed from the + BSP team to understand the actual hardware limits, and where they come from. -- cgit v1.2.3