[PATCH V3 06/12] drm/bridge: tc358767: Move hardware init to enable callback

[Lucas Stach]

Am Donnerstag, dem 24.02.2022 um 20:58 +0100 schrieb Marek Vasut:
> The TC358767/TC358867/TC9595 are all capable of operating either from
> attached Xtal or from DSI clock lane clock. In case the later is used,
> all I2C accesses will fail until the DSI clock lane is running and
> supplying clock to the chip.
> 
> Move all hardware initialization to enable callback to guarantee the
> DSI clock lane is running before accessing the hardware. In case Xtal
> is attached to the chip, this change has no effect. Operation without
> Xtal is currently not supported. The DSI-to-(e)DP mode is currently
> not supported and it might be difficult to implement without Xtal.
> 
I still think this might break setups that actually need the HPD and
AUX channel to detect the panel before setting up the display pipeline.
Maybe defer this patch into the series that actually enables refclock
from DSI lanes? Then you can just do the init at the point where it is
done now when the external refclock is available or move it (like done
in this patch) when required due to DSI clocking.

Regards,
Lucas

> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Jonas Karlman <jonas at kwiboo.se>
> Cc: Laurent Pinchart <Laurent.pinchart at ideasonboard.com>
> Cc: Maxime Ripard <maxime at cerno.tech>
> Cc: Neil Armstrong <narmstrong at baylibre.com>
> Cc: Sam Ravnborg <sam at ravnborg.org>
> ---
> V2: - Rebase on next-20220217
> V3: - Adjust commit message, point out operation without Xtal and
>       DSI-to-(e)DP modes are not supported yet.
> ---
>  drivers/gpu/drm/bridge/tc358767.c | 111 +++++++++++++++++-------------
>  1 file changed, 63 insertions(+), 48 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
> index e95153d9c1499..ea0d4467878f0 100644
> --- a/drivers/gpu/drm/bridge/tc358767.c
> +++ b/drivers/gpu/drm/bridge/tc358767.c
> @@ -1234,6 +1234,63 @@ static int tc_edp_stream_disable(struct tc_data *tc)
>  	return 0;
>  }
>  
> +static int tc_hardware_init(struct tc_data *tc)
> +{
> +	int ret;
> +
> +	ret = regmap_read(tc->regmap, TC_IDREG, &tc->rev);
> +	if (ret) {
> +		dev_err(tc->dev, "can not read device ID: %d\n", ret);
> +		return ret;
> +	}
> +
> +	if ((tc->rev != 0x6601) && (tc->rev != 0x6603)) {
> +		dev_err(tc->dev, "invalid device ID: 0x%08x\n", tc->rev);
> +		return -EINVAL;
> +	}
> +
> +	tc->assr = (tc->rev == 0x6601); /* Enable ASSR for eDP panels */
> +
> +	if (!tc->reset_gpio) {
> +		/*
> +		 * If the reset pin isn't present, do a software reset. It isn't
> +		 * as thorough as the hardware reset, as we can't reset the I2C
> +		 * communication block for obvious reasons, but it's getting the
> +		 * chip into a defined state.
> +		 */
> +		regmap_update_bits(tc->regmap, SYSRSTENB,
> +				ENBLCD0 | ENBBM | ENBDSIRX | ENBREG | ENBHDCP,
> +				0);
> +		regmap_update_bits(tc->regmap, SYSRSTENB,
> +				ENBLCD0 | ENBBM | ENBDSIRX | ENBREG | ENBHDCP,
> +				ENBLCD0 | ENBBM | ENBDSIRX | ENBREG | ENBHDCP);
> +		usleep_range(5000, 10000);
> +	}
> +
> +	if (tc->hpd_pin >= 0) {
> +		u32 lcnt_reg = tc->hpd_pin == 0 ? INT_GP0_LCNT : INT_GP1_LCNT;
> +		u32 h_lc = INT_GPIO_H(tc->hpd_pin) | INT_GPIO_LC(tc->hpd_pin);
> +
> +		/* Set LCNT to 2ms */
> +		regmap_write(tc->regmap, lcnt_reg,
> +			     clk_get_rate(tc->refclk) * 2 / 1000);
> +		/* We need the "alternate" mode for HPD */
> +		regmap_write(tc->regmap, GPIOM, BIT(tc->hpd_pin));
> +
> +		if (tc->have_irq) {
> +			/* enable H & LC */
> +			regmap_update_bits(tc->regmap, INTCTL_G, h_lc, h_lc);
> +		}
> +	}
> +
> +	if (tc->have_irq) {
> +		/* enable SysErr */
> +		regmap_write(tc->regmap, INTCTL_G, INT_SYSERR);
> +	}
> +
> +	return 0;
> +}
> +
>  static void
>  tc_edp_bridge_atomic_enable(struct drm_bridge *bridge,
>  			    struct drm_bridge_state *old_bridge_state)
> @@ -1241,6 +1298,12 @@ tc_edp_bridge_atomic_enable(struct drm_bridge *bridge,
>  	struct tc_data *tc = bridge_to_tc(bridge);
>  	int ret;
>  
> +	ret = tc_hardware_init(tc);
> +	if (ret < 0) {
> +		dev_err(tc->dev, "failed to initialize bridge: %d\n", ret);
> +		return;
> +	}
> +
>  	ret = tc_get_display_props(tc);
>  	if (ret < 0) {
>  		dev_err(tc->dev, "failed to read display props: %d\n", ret);
> @@ -1660,9 +1723,6 @@ static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  	}
>  
>  	if (client->irq > 0) {
> -		/* enable SysErr */
> -		regmap_write(tc->regmap, INTCTL_G, INT_SYSERR);
> -
>  		ret = devm_request_threaded_irq(dev, client->irq,
>  						NULL, tc_irq_handler,
>  						IRQF_ONESHOT,
> @@ -1675,51 +1735,6 @@ static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  		tc->have_irq = true;
>  	}
>  
> -	ret = regmap_read(tc->regmap, TC_IDREG, &tc->rev);
> -	if (ret) {
> -		dev_err(tc->dev, "can not read device ID: %d\n", ret);
> -		return ret;
> -	}
> -
> -	if ((tc->rev != 0x6601) && (tc->rev != 0x6603)) {
> -		dev_err(tc->dev, "invalid device ID: 0x%08x\n", tc->rev);
> -		return -EINVAL;
> -	}
> -
> -	tc->assr = (tc->rev == 0x6601); /* Enable ASSR for eDP panels */
> -
> -	if (!tc->reset_gpio) {
> -		/*
> -		 * If the reset pin isn't present, do a software reset. It isn't
> -		 * as thorough as the hardware reset, as we can't reset the I2C
> -		 * communication block for obvious reasons, but it's getting the
> -		 * chip into a defined state.
> -		 */
> -		regmap_update_bits(tc->regmap, SYSRSTENB,
> -				ENBLCD0 | ENBBM | ENBDSIRX | ENBREG | ENBHDCP,
> -				0);
> -		regmap_update_bits(tc->regmap, SYSRSTENB,
> -				ENBLCD0 | ENBBM | ENBDSIRX | ENBREG | ENBHDCP,
> -				ENBLCD0 | ENBBM | ENBDSIRX | ENBREG | ENBHDCP);
> -		usleep_range(5000, 10000);
> -	}
> -
> -	if (tc->hpd_pin >= 0) {
> -		u32 lcnt_reg = tc->hpd_pin == 0 ? INT_GP0_LCNT : INT_GP1_LCNT;
> -		u32 h_lc = INT_GPIO_H(tc->hpd_pin) | INT_GPIO_LC(tc->hpd_pin);
> -
> -		/* Set LCNT to 2ms */
> -		regmap_write(tc->regmap, lcnt_reg,
> -			     clk_get_rate(tc->refclk) * 2 / 1000);
> -		/* We need the "alternate" mode for HPD */
> -		regmap_write(tc->regmap, GPIOM, BIT(tc->hpd_pin));
> -
> -		if (tc->have_irq) {
> -			/* enable H & LC */
> -			regmap_update_bits(tc->regmap, INTCTL_G, h_lc, h_lc);
> -		}
> -	}
> -
>  	ret = tc_aux_link_setup(tc);
>  	if (ret)
>  		return ret;