linux-kernel - Re: [PATCH 1/2] drm/meson: dw-hdmi: power up phy on device init

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Message-ID: <bc8523bb-8d51-46c6-a011-7c46bb62acfa@linaro.org>
Date: Fri, 3 May 2024 10:42:36 +0200
From: Neil Armstrong <neil.armstrong@...aro.org>
To: Jerome Brunet <jbrunet@...libre.com>,
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>,
 David Airlie <airlied@...il.com>, Daniel Vetter <daniel@...ll.ch>
Cc: Kevin Hilman <khilman@...libre.com>,
 Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
 dri-devel@...ts.freedesktop.org, linux-amlogic@...ts.infradead.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] drm/meson: dw-hdmi: power up phy on device init

On 26/04/2024 18:02, Jerome Brunet wrote:
> The phy is not in a useful state right after init. It will become useful,
> including for auxiliary function such as CEC or ARC, after the first mode
> is set. This is a problem on systems where the display is using another
> interface like DSI or CVBS.
> 
> This change refactor the init and mode change callback to power up the PHY
> on init and leave only what is necessary for mode changes in the related
> function. This is enough to fix CEC operation when HDMI display is not
> enabled.
> 
> Fixes: 3f68be7d8e96 ("drm/meson: Add support for HDMI encoder and DW-HDMI bridge + PHY")
> Signed-off-by: Jerome Brunet <jbrunet@...libre.com>
> ---
>   drivers/gpu/drm/meson/meson_dw_hdmi.c | 51 +++++++++------------------
>   1 file changed, 17 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> index 5a9538bc0e26..a83d93078537 100644
> --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
> +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> @@ -384,26 +384,6 @@ static int dw_hdmi_phy_init(struct dw_hdmi *hdmi, void *data,
>   	    dw_hdmi_bus_fmt_is_420(hdmi))
>   		mode_is_420 = true;
>   
> -	/* Enable clocks */
> -	regmap_update_bits(priv->hhi, HHI_HDMI_CLK_CNTL, 0xffff, 0x100);
> -
> -	/* Bring HDMITX MEM output of power down */
> -	regmap_update_bits(priv->hhi, HHI_MEM_PD_REG0, 0xff << 8, 0);
> -
> -	/* Bring out of reset */
> -	dw_hdmi->data->top_write(dw_hdmi, HDMITX_TOP_SW_RESET,  0);
> -
> -	/* Enable internal pixclk, tmds_clk, spdif_clk, i2s_clk, cecclk */
> -	dw_hdmi_top_write_bits(dw_hdmi, HDMITX_TOP_CLK_CNTL,
> -			       0x3, 0x3);
> -
> -	/* Enable cec_clk and hdcp22_tmdsclk_en */
> -	dw_hdmi_top_write_bits(dw_hdmi, HDMITX_TOP_CLK_CNTL,
> -			       0x3 << 4, 0x3 << 4);
> -
> -	/* Enable normal output to PHY */
> -	dw_hdmi->data->top_write(dw_hdmi, HDMITX_TOP_BIST_CNTL, BIT(12));
> -
>   	/* TMDS pattern setup */
>   	if (mode->clock > 340000 && !mode_is_420) {
>   		dw_hdmi->data->top_write(dw_hdmi, HDMITX_TOP_TMDS_CLK_PTTN_01,
> @@ -425,20 +405,6 @@ static int dw_hdmi_phy_init(struct dw_hdmi *hdmi, void *data,
>   	/* Setup PHY parameters */
>   	meson_hdmi_phy_setup_mode(dw_hdmi, mode, mode_is_420);
>   
> -	/* Setup PHY */
> -	regmap_update_bits(priv->hhi, HHI_HDMI_PHY_CNTL1,
> -			   0xffff << 16, 0x0390 << 16);
> -
> -	/* BIT_INVERT */
> -	if (dw_hdmi_is_compatible(dw_hdmi, "amlogic,meson-gxl-dw-hdmi") ||
> -	    dw_hdmi_is_compatible(dw_hdmi, "amlogic,meson-gxm-dw-hdmi") ||
> -	    dw_hdmi_is_compatible(dw_hdmi, "amlogic,meson-g12a-dw-hdmi"))
> -		regmap_update_bits(priv->hhi, HHI_HDMI_PHY_CNTL1,
> -				   BIT(17), 0);
> -	else
> -		regmap_update_bits(priv->hhi, HHI_HDMI_PHY_CNTL1,
> -				   BIT(17), BIT(17));
> -
>   	/* Disable clock, fifo, fifo_wr */
>   	regmap_update_bits(priv->hhi, HHI_HDMI_PHY_CNTL1, 0xf, 0);
>   
> @@ -656,6 +622,23 @@ static void meson_dw_hdmi_init(struct meson_dw_hdmi *meson_dw_hdmi)
>   	meson_dw_hdmi->data->top_write(meson_dw_hdmi,
>   				       HDMITX_TOP_CLK_CNTL, 0xff);
>   
> +	/* Enable normal output to PHY */
> +	meson_dw_hdmi->data->top_write(meson_dw_hdmi, HDMITX_TOP_BIST_CNTL, BIT(12));
> +
> +	/* Setup PHY */
> +	regmap_update_bits(priv->hhi, HHI_HDMI_PHY_CNTL1,
> +			   0xffff << 16, 0x0390 << 16);
> +
> +	/* BIT_INVERT */
> +	if (dw_hdmi_is_compatible(meson_dw_hdmi, "amlogic,meson-gxl-dw-hdmi") ||
> +	    dw_hdmi_is_compatible(meson_dw_hdmi, "amlogic,meson-gxm-dw-hdmi") ||
> +	    dw_hdmi_is_compatible(meson_dw_hdmi, "amlogic,meson-g12a-dw-hdmi"))
> +		regmap_update_bits(priv->hhi, HHI_HDMI_PHY_CNTL1,
> +				   BIT(17), 0);
> +	else
> +		regmap_update_bits(priv->hhi, HHI_HDMI_PHY_CNTL1,
> +				   BIT(17), BIT(17));
> +
>   	/* Enable HDMI-TX Interrupt */
>   	meson_dw_hdmi->data->top_write(meson_dw_hdmi, HDMITX_TOP_INTR_STAT_CLR,
>   				       HDMITX_TOP_INTR_CORE);

Reviewed-by: Neil Armstrong <neil.armstrong@...aro.org>