From 106b4a2a78b2a2f14885604891957b84bba502db Mon Sep 17 00:00:00 2001 From: Adrian Betschart Date: Fri, 11 Sep 2026 17:13:14 +0200 Subject: drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validation amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and uses the first encoding that validates. YCbCr 4:4:4 is listed before RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the "color format" property is left at AUTO, even though RGB fits the same link. That contradicts the documented AUTO behaviour for HDMI in enum drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when the bandwidth is not available or the mode is 4:2:0-only), which the amdgpu implementation of the property also describes. It also leaves the "Broadcast RGB" property without effect on such sinks, since the quantization range it selects only applies to RGB output. Try RGB first. The mask still holds every encoding the sink supports, so a mode that cannot carry RGB falls back exactly as before. For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI sink that advertised it. Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation") Suggested-by: Adolfo Rodrigues Assisted-by: Claude Code:claude-fable-5-1 Signed-off-by: Adrian Betschart Reviewed-by: Fangzhi Zuo Tested-by: Adolfo Rodrigues Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7) --- drivers/gpu/drm/mcde/Kconfig | 18 + drivers/gpu/drm/mcde/Makefile | 3 + drivers/gpu/drm/mcde/mcde_clk_div.c | 196 ++++ drivers/gpu/drm/mcde/mcde_display.c | 1523 ++++++++++++++++++++++++++++++ drivers/gpu/drm/mcde/mcde_display_regs.h | 605 ++++++++++++ drivers/gpu/drm/mcde/mcde_drm.h | 118 +++ drivers/gpu/drm/mcde/mcde_drv.c | 522 ++++++++++ drivers/gpu/drm/mcde/mcde_dsi.c | 1242 ++++++++++++++++++++++++ drivers/gpu/drm/mcde/mcde_dsi_regs.h | 385 ++++++++ 9 files changed, 4612 insertions(+) create mode 100644 drivers/gpu/drm/mcde/Kconfig create mode 100644 drivers/gpu/drm/mcde/Makefile create mode 100644 drivers/gpu/drm/mcde/mcde_clk_div.c create mode 100644 drivers/gpu/drm/mcde/mcde_display.c create mode 100644 drivers/gpu/drm/mcde/mcde_display_regs.h create mode 100644 drivers/gpu/drm/mcde/mcde_drm.h create mode 100644 drivers/gpu/drm/mcde/mcde_drv.c create mode 100644 drivers/gpu/drm/mcde/mcde_dsi.c create mode 100644 drivers/gpu/drm/mcde/mcde_dsi_regs.h (limited to 'drivers/gpu/drm/mcde') diff --git a/drivers/gpu/drm/mcde/Kconfig b/drivers/gpu/drm/mcde/Kconfig new file mode 100644 index 000000000..3516c8d2a --- /dev/null +++ b/drivers/gpu/drm/mcde/Kconfig @@ -0,0 +1,18 @@ +config DRM_MCDE + tristate "DRM Support for ST-Ericsson MCDE (Multichannel Display Engine)" + depends on DRM + depends on CMA + depends on ARM || COMPILE_TEST + depends on OF + depends on COMMON_CLK + select MFD_SYSCON + select DRM_CLIENT_SELECTION + select DRM_MIPI_DSI + select DRM_BRIDGE + select DRM_PANEL_BRIDGE + select DRM_KMS_HELPER + select DRM_GEM_DMA_HELPER + help + Choose this option for DRM support for the ST-Ericsson MCDE + Multi-Channel Display Engine. + If M is selected the module will be called mcde_drm. diff --git a/drivers/gpu/drm/mcde/Makefile b/drivers/gpu/drm/mcde/Makefile new file mode 100644 index 000000000..15d9c89a3 --- /dev/null +++ b/drivers/gpu/drm/mcde/Makefile @@ -0,0 +1,3 @@ +mcde_drm-y += mcde_drv.o mcde_dsi.o mcde_clk_div.o mcde_display.o + +obj-$(CONFIG_DRM_MCDE) += mcde_drm.o diff --git a/drivers/gpu/drm/mcde/mcde_clk_div.c b/drivers/gpu/drm/mcde/mcde_clk_div.c new file mode 100644 index 000000000..8c5af2677 --- /dev/null +++ b/drivers/gpu/drm/mcde/mcde_clk_div.c @@ -0,0 +1,196 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include + +#include "mcde_drm.h" +#include "mcde_display_regs.h" + +/* The MCDE internal clock dividers for FIFO A and B */ +struct mcde_clk_div { + struct clk_hw hw; + struct mcde *mcde; + u32 cr; + u32 cr_div; +}; + +static int mcde_clk_div_enable(struct clk_hw *hw) +{ + struct mcde_clk_div *cdiv = container_of(hw, struct mcde_clk_div, hw); + struct mcde *mcde = cdiv->mcde; + u32 val; + + spin_lock(&mcde->fifo_crx1_lock); + val = readl(mcde->regs + cdiv->cr); + /* + * Select the PLL72 (LCD) clock as parent + * FIXME: implement other parents. + */ + val &= ~MCDE_CRX1_CLKSEL_MASK; + val |= MCDE_CRX1_CLKSEL_CLKPLL72 << MCDE_CRX1_CLKSEL_SHIFT; + /* Internal clock */ + val |= MCDE_CRA1_CLKTYPE_TVXCLKSEL1; + + /* Clear then set the divider */ + val &= ~(MCDE_CRX1_BCD | MCDE_CRX1_PCD_MASK); + val |= cdiv->cr_div; + + writel(val, mcde->regs + cdiv->cr); + spin_unlock(&mcde->fifo_crx1_lock); + + return 0; +} + +static int mcde_clk_div_choose_div(struct clk_hw *hw, unsigned long rate, + unsigned long *prate, bool set_parent) +{ + int best_div = 1, div; + struct clk_hw *parent = clk_hw_get_parent(hw); + unsigned long best_prate = 0; + unsigned long best_diff = ~0ul; + int max_div = (1 << MCDE_CRX1_PCD_BITS) - 1; + + for (div = 1; div < max_div; div++) { + unsigned long this_prate, div_rate, diff; + + if (set_parent) + this_prate = clk_hw_round_rate(parent, rate * div); + else + this_prate = *prate; + div_rate = DIV_ROUND_UP_ULL(this_prate, div); + diff = abs(rate - div_rate); + + if (diff < best_diff) { + best_div = div; + best_diff = diff; + best_prate = this_prate; + } + } + + *prate = best_prate; + return best_div; +} + +static int mcde_clk_div_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + int div = mcde_clk_div_choose_div(hw, req->rate, + &req->best_parent_rate, true); + + req->rate = DIV_ROUND_UP_ULL(req->best_parent_rate, div); + + return 0; +} + +static unsigned long mcde_clk_div_recalc_rate(struct clk_hw *hw, + unsigned long prate) +{ + struct mcde_clk_div *cdiv = container_of(hw, struct mcde_clk_div, hw); + struct mcde *mcde = cdiv->mcde; + u32 cr; + int div; + + /* + * If the MCDE is not powered we can't access registers. + * It will come up with 0 in the divider register bits, which + * means "divide by 2". + */ + if (!regulator_is_enabled(mcde->epod)) + return DIV_ROUND_UP_ULL(prate, 2); + + cr = readl(mcde->regs + cdiv->cr); + if (cr & MCDE_CRX1_BCD) + return prate; + + /* 0 in the PCD means "divide by 2", 1 means "divide by 3" etc */ + div = cr & MCDE_CRX1_PCD_MASK; + div += 2; + + return DIV_ROUND_UP_ULL(prate, div); +} + +static int mcde_clk_div_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long prate) +{ + struct mcde_clk_div *cdiv = container_of(hw, struct mcde_clk_div, hw); + int div = mcde_clk_div_choose_div(hw, rate, &prate, false); + u32 cr = 0; + + /* + * We cache the CR bits to set the divide in the state so that + * we can call this before we can even write to the hardware. + */ + if (div == 1) { + /* Bypass clock divider */ + cr |= MCDE_CRX1_BCD; + } else { + div -= 2; + cr |= div & MCDE_CRX1_PCD_MASK; + } + cdiv->cr_div = cr; + + return 0; +} + +static const struct clk_ops mcde_clk_div_ops = { + .enable = mcde_clk_div_enable, + .recalc_rate = mcde_clk_div_recalc_rate, + .determine_rate = mcde_clk_div_determine_rate, + .set_rate = mcde_clk_div_set_rate, +}; + +int mcde_init_clock_divider(struct mcde *mcde) +{ + struct device *dev = mcde->dev; + struct mcde_clk_div *fifoa; + struct mcde_clk_div *fifob; + const char *parent_name; + struct clk_init_data fifoa_init = { + .name = "fifoa", + .ops = &mcde_clk_div_ops, + .parent_names = &parent_name, + .num_parents = 1, + .flags = CLK_SET_RATE_PARENT, + }; + struct clk_init_data fifob_init = { + .name = "fifob", + .ops = &mcde_clk_div_ops, + .parent_names = &parent_name, + .num_parents = 1, + .flags = CLK_SET_RATE_PARENT, + }; + int ret; + + spin_lock_init(&mcde->fifo_crx1_lock); + parent_name = __clk_get_name(mcde->lcd_clk); + + /* Allocate 2 clocks */ + fifoa = devm_kzalloc(dev, sizeof(*fifoa), GFP_KERNEL); + if (!fifoa) + return -ENOMEM; + fifob = devm_kzalloc(dev, sizeof(*fifob), GFP_KERNEL); + if (!fifob) + return -ENOMEM; + + fifoa->mcde = mcde; + fifoa->cr = MCDE_CRA1; + fifoa->hw.init = &fifoa_init; + ret = devm_clk_hw_register(dev, &fifoa->hw); + if (ret) { + dev_err(dev, "error registering FIFO A clock divider\n"); + return ret; + } + mcde->fifoa_clk = fifoa->hw.clk; + + fifob->mcde = mcde; + fifob->cr = MCDE_CRB1; + fifob->hw.init = &fifob_init; + ret = devm_clk_hw_register(dev, &fifob->hw); + if (ret) { + dev_err(dev, "error registering FIFO B clock divider\n"); + return ret; + } + mcde->fifob_clk = fifob->hw.clk; + + return 0; +} diff --git a/drivers/gpu/drm/mcde/mcde_display.c b/drivers/gpu/drm/mcde/mcde_display.c new file mode 100644 index 000000000..257a6e84d --- /dev/null +++ b/drivers/gpu/drm/mcde/mcde_display.c @@ -0,0 +1,1523 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018 Linus Walleij + * Parts of this file were based on the MCDE driver by Marcus Lorentzon + * (C) ST-Ericsson SA 2013 + */ +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include