Subject: Re: [PATCH RESEND v2 05/12] drm/bridge: Add Analogix anx6345 support

From: Torsten Duwe <[email-masked]>
Date: Tue, 5 Feb 2019 14:19:02 +0100

First thing that struck me is that the chip's reset is actually low active

   reset-gpios = <&pio 3 24 GPIO_ACTIVE_LOW>; /* PD24 */
                                        ^^^^
(please correct this in patches 11 and 12)

Consequently, you're using inverted values here in the driver:

> +static void anx6345_poweron(struct anx6345 *anx6345)
> +{
[...]
> +	gpiod_set_value_cansleep(pdata->gpiod_reset, 0);

0 = reset on, ok.

> +	usleep_range(1000, 2000);
> +
> +	gpiod_set_value_cansleep(pdata->gpiod_reset, 1);

1 = reset off, also fine.

> +
> +	/* Power on registers module */
> +	anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM], SP_POWERDOWN_CTRL_REG,
> +			 SP_HDCP_PD | SP_AUDIO_PD | SP_VIDEO_PD | SP_LINK_PD);
> +	anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM], SP_POWERDOWN_CTRL_REG,
> +			   SP_REGISTER_PD | SP_TOTAL_PD);
> +
> +	anx6345->powered = true;
> +}
> +
> +static void anx6345_poweroff(struct anx6345 *anx6345)
> +{
> +	struct anx6345_platform_data *pdata = &anx6345->pdata;
> +	int err;
> +
> +	if (WARN_ON(!anx6345->powered))
> +		return;
> +
> +	gpiod_set_value_cansleep(pdata->gpiod_reset, 1);
> +	usleep_range(1000, 2000);

This one got me a bit confused. Assert or deassert reset (again) before
poweroff?

Please stick to the logical value of the reset line.

	Torsten

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