Re: [RFC PATCH 2/2] drm/mediatek: add mtk8195 hdmi display driver

[CK Hu <ck.hu@mediatek.com>]

Hi, Guillaume:

On Mon, 2021-11-08 at 01:08 +0100, Guillaume Ranquet wrote:
> Signed-off-by: Guillaume Ranquet <granquet@baylibre.com>
> Change-Id: I6399dec26cfe56a338c2ca96989cb7cbd14e292b
> ---
>  drivers/gpu/drm/mediatek/Kconfig              |    9 +
>  drivers/gpu/drm/mediatek/Makefile             |    2 +
>  drivers/gpu/drm/mediatek/mtk_hdmi_common.c    |  219 +-
>  drivers/gpu/drm/mediatek/mtk_hdmi_common.h    |   24 +-
>  drivers/gpu/drm/mediatek/mtk_mt8195_hdmi.c    | 1835
> +++++++++++++++++
>  drivers/gpu/drm/mediatek/mtk_mt8195_hdmi.h    |   26 +
>  .../gpu/drm/mediatek/mtk_mt8195_hdmi_ddc.c    |  530 +++++
>  .../gpu/drm/mediatek/mtk_mt8195_hdmi_ddc.h    |   20 +
>  .../gpu/drm/mediatek/mtk_mt8195_hdmi_regs.h   |  329 +++
>  9 files changed, 2932 insertions(+), 62 deletions(-)
>  create mode 100644 drivers/gpu/drm/mediatek/mtk_mt8195_hdmi.c
>  create mode 100644 drivers/gpu/drm/mediatek/mtk_mt8195_hdmi.h
>  create mode 100644 drivers/gpu/drm/mediatek/mtk_mt8195_hdmi_ddc.c
>  create mode 100644 drivers/gpu/drm/mediatek/mtk_mt8195_hdmi_ddc.h
>  create mode 100644 drivers/gpu/drm/mediatek/mtk_mt8195_hdmi_regs.h
> 
> diff --git a/drivers/gpu/drm/mediatek/Kconfig
> b/drivers/gpu/drm/mediatek/Kconfig
> index 0df75bceb74e..76cc402cbd75 100644
> --- a/drivers/gpu/drm/mediatek/Kconfig
> +++ b/drivers/gpu/drm/mediatek/Kconfig
> @@ -31,3 +31,12 @@ config DRM_MEDIATEK_HDMI
>  	help
>  	  DRM/KMS HDMI driver for Mediatek SoCs

[snip]

> +
> +static int mtk_hdmi_ddc_xfer(struct i2c_adapter *adapter, struct
> i2c_msg *msgs,
> +			     int num)
> +{
> +	struct mtk_hdmi_ddc *ddc = adapter->algo_data;
> +	struct device *dev = adapter->dev.parent;
> +	int ret;
> +	int i;
> +
> +	if (!ddc)
> +		return -EINVAL;
> +
> +	for (i = 0; i < num; i++) {
> +		struct i2c_msg *msg = &msgs[i];
> +
> +		if (msg->flags & I2C_M_RD)
> +			ret = fg_ddc_data_read(ddc, msg->addr, msg-
> >buf[0],
> +					    (msg->len), &msg->buf[0]);
> +		else
> +			ret = fg_ddc_data_write(ddc, msg->addr, msg-
> >buf[0],
> +					     (msg->len - 1), &msg-
> >buf[1]);

Why do you use msg->buf[1]? In mt8173 hdmi ddc driver,
mtk_hdmi_ddc_write_msg() just use msg->buf[0]. If using msg->buf[1] is
advance function, separate this advance function to another patch.

Regards,
CK

> +
> +		if (ret <= 0)
> +			goto xfer_end;
> +	}
> +
> +	return i;
> +
> +xfer_end:
> +	dev_err(dev, "ddc failed! : %d\n", ret);
> +	return ret;
> +}
> +