From 831f9216a79a2930ecd449116889ef74f29a7411 Mon Sep 17 00:00:00 2001 From: AngeloGioacchino Del Regno Date: Fri, 3 Nov 2023 11:25:32 +0100 Subject: clk: mediatek: mt8195-topckgen: Refactor parents for top_dp/edp muxes The top_dp and top_edp muxes can be both parented to either TVDPLL1 or TVDPLL2, two identically specced PLLs for the specific purpose of giving out pixel clock: this becomes a problem when the MediaTek DisplayPort Interface (DPI) driver tries to set the pixel clock rate. In the usecase of two simultaneous outputs (using two controllers), it was seen that one of the displays would sometimes display garbled output (if any at all) and this was because: - top_edp was set to TVDPLL1, outputting X GHz - top_dp was set to TVDPLL2, outputting Y GHz - mtk_dpi calls clk_set_rate(top_edp, Z GHz) - top_dp is switched to TVDPLL1 - TVDPLL1 changes its rate, top_edp outputs the wrong rate. - eDP display is garbled To solve this issue, remove all TVDPLL1 parents from `top_dp` and all TVDPLL2 parents from `top_edp`, plus, necessarily switch both clocks to use the new MUX_GATE_CLR_SET_UPD_INDEXED() macro to be able to use the right bit index for the new parents list. Reviewed-by: Alexandre Mergnat Reviewed-by: Chen-Yu Tsai Signed-off-by: AngeloGioacchino Del Regno Link: https://lore.kernel.org/r/20231103102533.69280-3-angelogioacchino.delregno@collabora.com Reviewed-by: Fei Shao Signed-off-by: Stephen Boyd --- drivers/clk/mediatek/clk-mt8195-topckgen.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-) (limited to 'drivers/clk/mediatek') diff --git a/drivers/clk/mediatek/clk-mt8195-topckgen.c b/drivers/clk/mediatek/clk-mt8195-topckgen.c index 5c426a1c94c7..8f713a3341a9 100644 --- a/drivers/clk/mediatek/clk-mt8195-topckgen.c +++ b/drivers/clk/mediatek/clk-mt8195-topckgen.c @@ -415,17 +415,28 @@ static const char * const pwrmcu_parents[] = { "mainpll_d4_d2" }; +/* + * Both DP/eDP can be parented to TVDPLL1 and TVDPLL2, but we force using + * TVDPLL1 on eDP and TVDPLL2 on DP to avoid changing the "other" PLL rate + * in dual output case, which would lead to corruption of functionality loss. + */ static const char * const dp_parents[] = { "clk26m", - "tvdpll1_d2", "tvdpll2_d2", - "tvdpll1_d4", "tvdpll2_d4", - "tvdpll1_d8", "tvdpll2_d8", - "tvdpll1_d16", "tvdpll2_d16" }; +static const u8 dp_parents_idx[] = { 0, 2, 4, 6, 8 }; + +static const char * const edp_parents[] = { + "clk26m", + "tvdpll1_d2", + "tvdpll1_d4", + "tvdpll1_d8", + "tvdpll1_d16" +}; +static const u8 edp_parents_idx[] = { 0, 1, 3, 5, 7 }; static const char * const disp_pwm_parents[] = { "clk26m", @@ -957,11 +968,11 @@ static const struct mtk_mux top_mtk_muxes[] = { MUX_GATE_CLR_SET_UPD_FLAGS(CLK_TOP_PWRMCU, "top_pwrmcu", pwrmcu_parents, 0x08C, 0x090, 0x094, 16, 3, 23, 0x08, 6, CLK_IS_CRITICAL | CLK_SET_RATE_PARENT), - MUX_GATE_CLR_SET_UPD(CLK_TOP_DP, "top_dp", - dp_parents, 0x08C, 0x090, 0x094, 24, 4, 31, 0x08, 7), + MUX_GATE_CLR_SET_UPD_INDEXED(CLK_TOP_DP, "top_dp", + dp_parents, dp_parents_idx, 0x08C, 0x090, 0x094, 24, 4, 31, 0x08, 7), /* CLK_CFG_10 */ - MUX_GATE_CLR_SET_UPD(CLK_TOP_EDP, "top_edp", - dp_parents, 0x098, 0x09C, 0x0A0, 0, 4, 7, 0x08, 8), + MUX_GATE_CLR_SET_UPD_INDEXED(CLK_TOP_EDP, "top_edp", + edp_parents, edp_parents_idx, 0x098, 0x09C, 0x0A0, 0, 4, 7, 0x08, 8), MUX_GATE_CLR_SET_UPD(CLK_TOP_DPI, "top_dpi", dp_parents, 0x098, 0x09C, 0x0A0, 8, 4, 15, 0x08, 9), MUX_GATE_CLR_SET_UPD(CLK_TOP_DISP_PWM0, "top_disp_pwm0", -- cgit v1.2.3