On 10/30/26 19:01, Heiko Stuebner wrote:
> Am Donnerstag, 29. Oktober 2026, 08:53:43 Mitteleuropäische Normalzeit
> schrieb Michal Wilczynski:
>> 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.
>>
>> Reviewed-by: Joshua Peisach <[email protected]>
>> Tested-by: Byron Stanoszek <[email protected]>
>> Tested-by: OOHehir <[email protected]>
>> Signed-off-by: Michal Wilczynski <[email protected]>
>> ---
>> 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
>> 222f6522844ee60ae9a07ab2dcca748dbf7403e4..a8905bf627a224d7e3918514195f1810164dc26f
>> 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);
>> }
>>
>> @@ -1101,9 +1116,19 @@ 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);
>> + }
>
> why can't you just also use a mmio regmap here? Because with this change
> the driver now has 2 competing register interfaces and you need those
> conditionals all the time.
>
> Just convert the existing user to also use a regmap please.
OK. In v7 inno-hdmi will use a regmap.
Parent's where one exists, and otherwise a devm_regmap_init_mmio()
covering its own resource. hdmi_readb()/hdmi_writeb() can then drop
the conditionals.
That also switches rockchip hw from readl/writel over to regmap. I
can only build test those two so a Tested-by from anyone with the
actual hardware would be appreciated.
>
>
> Heiko
>
>
>
>
Best regards,
--
Michal Wilczynski <[email protected]>
