[PATCH v3 08/19] drm/bridge: inno-hdmi: Allow the register map to come from a parent
From: Michal Wilczynski <m.wilczynski@samsung.com>
Date: 2026-09-04 13:27:29
Also in:
dri-devel, linux-clk, linux-devicetree, linux-phy, linux-riscv, linux-rockchip, lkml
Subsystem:
drm drivers, drm drivers and misc gpu patches, drm drivers for bridge chips, innosilicon hdmi bridge driver, the rest · Maintainers:
David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Andrzej Hajda, Neil Armstrong, Robert Foss, Andy Yan, Linus Torvalds
On some SoCs the HDMI controller does not own its register window. The StarFive JH7110 documents one 64 KB block, u0_hdmitx, that holds both the controller and the PHY, so the parent device maps it and owns the regmap while the two children share it. Use a regmap supplied by the parent device when there is one, and keep mapping our own resource when there is not, so platforms that own their register window are unaffected. Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com> --- drivers/gpu/drm/bridge/inno-hdmi.c | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/bridge/inno-hdmi.c b/drivers/gpu/drm/bridge/inno-hdmi.c
index aab474740f7f57aa34007e6dac49e2414561593f..8bd771761180473d221f59d5c0cd2a636e96ac4c 100644
--- a/drivers/gpu/drm/bridge/inno-hdmi.c
+++ b/drivers/gpu/drm/bridge/inno-hdmi.c@@ -397,6 +397,7 @@ struct inno_hdmi { struct clk *pclk; struct clk *refclk; void __iomem *regs; + struct regmap *regmap; struct regmap *grf; struct inno_hdmi_i2c *i2c;
@@ -470,11 +471,25 @@ static int inno_hdmi_find_phy_config(struct inno_hdmi *hdmi, static inline u8 hdmi_readb(struct inno_hdmi *hdmi, u16 offset) { + u32 val; + + if (hdmi->regmap) { + if (regmap_read(hdmi->regmap, offset * 4, &val)) + return 0; + + return val; + } + return readl_relaxed(hdmi->regs + (offset) * 0x04); } static inline void hdmi_writeb(struct inno_hdmi *hdmi, u16 offset, u32 val) { + if (hdmi->regmap) { + regmap_write(hdmi->regmap, offset * 4, val); + return; + } + writel_relaxed(val, hdmi->regs + (offset) * 0x04); }
@@ -1095,9 +1110,19 @@ struct inno_hdmi *inno_hdmi_probe(struct platform_device *pdev, hdmi->dev = dev; hdmi->plat_data = plat_data; - hdmi->regs = devm_platform_ioremap_resource(pdev, 0); - if (IS_ERR(hdmi->regs)) - return ERR_CAST(hdmi->regs); + /* + * On platforms where the controller shares a register space with + * other blocks, the parent owns the regmap. Fall back to mapping + * our own resource where it does not. + */ + if (dev->parent) + hdmi->regmap = dev_get_regmap(dev->parent, NULL); + + if (!hdmi->regmap) { + hdmi->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(hdmi->regs)) + return ERR_CAST(hdmi->regs); + } hdmi->pclk = devm_clk_get_enabled(hdmi->dev, "pclk"); if (IS_ERR(hdmi->pclk)) {
--
2.34.1