Re: [PATCH 03/89] i2c: brcmstb: Support BCM2711 HDMI BSC controllers

From: Florian Fainelli
Date: Mon Feb 24 2020 - 12:45:05 EST


On 2/24/20 1:06 AM, Maxime Ripard wrote:
> The HDMI blocks in the BCM2771 have an i2c controller to retrieve the
> EDID. This block is split into two parts, the BSC and the AUTO_I2C,
> lying in two separate register areas.
>
> The AUTO_I2C block has a mailbox-like interface and will take away the
> BSC control from the CPU if enabled. However, the BSC is the actually
> the same controller than the one supported by the brcmstb driver, and
> the AUTO_I2C doesn't really bring any immediate benefit.
>
> Let's use the BSC then, but let's also tie the AUTO_I2C registers with a
> separate compatible so that we can enable AUTO_I2C if needed in the
> future.
>
> The AUTO_I2C is enabled by default at boot though, so we first need to
> release the BSC from the AUTO_I2C control.
>
> Cc: Kamal Dasu <kdasu.kdev@xxxxxxxxx>
> Cc: Florian Fainelli <f.fainelli@xxxxxxxxx>
> Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
> Cc: bcm-kernel-feedback-list@xxxxxxxxxxxx
> Cc: linux-i2c@xxxxxxxxxxxxxxx
> Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>

[snip]

> @@ -705,6 +737,7 @@ static SIMPLE_DEV_PM_OPS(brcmstb_i2c_pm, brcmstb_i2c_suspend,
> static const struct of_device_id brcmstb_i2c_of_match[] = {
> {.compatible = "brcm,brcmstb-i2c"},
> {.compatible = "brcm,brcmper-i2c"},
> + {.compatible = "brcm,bcm2711-hdmi-i2c"},

You could have added the bcm2711_release_bsc here as a function attached
with the of_device_id::data member of the structure and do:

if (data && data->init_func)
rc = data->init_func(dev);

But we can defer that until we have a second compatible string that
requires the same approach.

Akked-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
--
Florian