Message-ID: <90ff31e5-3bed-40d2-8476-1ebb772c03f3@wanadoo.fr>
Date: Fri, 1 Nov 2024 17:56:04 +0100
From: Christophe JAILLET <christophe.jaillet@...adoo.fr>
To: Abel Vesa <abel.vesa@...aro.org>
Cc: linux-arm-msm@...r.kernel.org, Bjorn Andersson <andersson@...nel.org>,
 Konrad Dybcio <konradybcio@...nel.org>,
 Rajendra Nayak <quic_rjendra@...cinc.com>,
 Sibi Sankar <quic_sibis@...cinc.com>, Johan Hovold <johan@...nel.org>,
 Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
 Trilok Soni <quic_tsoni@...cinc.com>, linux-kernel@...r.kernel.org,
 linux-usb@...r.kernel.org, devicetree@...r.kernel.org,
 Abel Vesa <abel.vesa@...aro.org>,
 Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
 Conor Dooley <conor+dt@...nel.org>
Subject: Re: [PATCH v4 2/4] usb: typec: Add support for Parade PS8830 Type-C
 Retimer

Le 01/11/2024 à 17:29, Abel Vesa a écrit :
> The Parade PS8830 is a USB4, DisplayPort and Thunderbolt 4 retimer,
> controlled over I2C. It usually sits between a USB/DisplayPort PHY
> and the Type-C connector, and provides orientation and altmode handling.
> 
> The boards that use this retimer are the ones featuring the Qualcomm
> Snapdragon X Elite SoCs.
> 
> Add a driver with support for the following modes:
>   - DisplayPort 4-lanes
>   - DisplayPort 2-lanes + USB3
>   - USB3
> 
> There is another variant of this retimer which is called PS8833. It seems
> to be really similar to the PS8830, so future-proof this driver by
> naming it ps883x.
> 
> Signed-off-by: Abel Vesa <abel.vesa-QSEj5FYQhm4dnm+yROfE0A@...lic.gmane.org>
> ---

Hi,

...

> +static void ps883x_disable_vregs(struct ps883x_retimer *retimer)
> +{
> +	regulator_disable(retimer->vddio_supply);
> +	regulator_disable(retimer->vddat_supply);
> +	regulator_disable(retimer->vddar_supply);
> +	regulator_disable(retimer->vdd_supply);
> +	regulator_disable(retimer->vdd33_cap_supply);
> +	regulator_disable(retimer->vdd33_supply);
> +}
> +
> +static int ps883x_get_vregs(struct ps883x_retimer *retimer)

This could maybe be replaced by a
devm_regulator_bulk_get() call?
(and use the bulk API in other places)

> +{
> +	struct device *dev = &retimer->client->dev;
> +
> +	retimer->vdd_supply = devm_regulator_get(dev, "vdd");
> +	if (IS_ERR(retimer->vdd_supply))
> +		return dev_err_probe(dev, PTR_ERR(retimer->vdd_supply),
> +				     "failed to get VDD\n");
> +
> +	retimer->vdd33_supply = devm_regulator_get(dev, "vdd33");
> +	if (IS_ERR(retimer->vdd33_supply))
> +		return dev_err_probe(dev, PTR_ERR(retimer->vdd33_supply),
> +				     "failed to get VDD 3.3V\n");
> +
> +	retimer->vdd33_cap_supply = devm_regulator_get(dev, "vdd33-cap");
> +	if (IS_ERR(retimer->vdd33_cap_supply))
> +		return dev_err_probe(dev, PTR_ERR(retimer->vdd33_cap_supply),
> +				     "failed to get VDD CAP 3.3V\n");
> +
> +	retimer->vddat_supply = devm_regulator_get(dev, "vddat");
> +	if (IS_ERR(retimer->vddat_supply))
> +		return dev_err_probe(dev, PTR_ERR(retimer->vddat_supply),
> +				     "failed to get VDD AT\n");
> +
> +	retimer->vddar_supply = devm_regulator_get(dev, "vddar");
> +	if (IS_ERR(retimer->vddar_supply))
> +		return dev_err_probe(dev, PTR_ERR(retimer->vddar_supply),
> +				     "failed to get VDD AR\n");
> +
> +	retimer->vddio_supply = devm_regulator_get(dev, "vddio");
> +	if (IS_ERR(retimer->vddio_supply))
> +		return dev_err_probe(dev, PTR_ERR(retimer->vddio_supply),
> +				     "failed to get VDD IO\n");
> +
> +	return 0;
> +}

...

> +static int ps883x_retimer_probe(struct i2c_client *client)
> +{
> +	struct device *dev = &client->dev;
> +	struct typec_switch_desc sw_desc = { };
> +	struct typec_retimer_desc rtmr_desc = { };
> +	struct ps883x_retimer *retimer;
> +	int ret;
> +
> +	retimer = devm_kzalloc(dev, sizeof(*retimer), GFP_KERNEL);
> +	if (!retimer)
> +		return -ENOMEM;
> +
> +	retimer->client = client;
> +
> +	mutex_init(&retimer->lock);
> +
> +	retimer->regmap = devm_regmap_init_i2c(client, &ps883x_retimer_regmap);
> +	if (IS_ERR(retimer->regmap)) {
> +		ret = PTR_ERR(retimer->regmap);
> +		dev_err(dev, "failed to allocate register map: %d\n", ret);

Maybe dev_err_probe() as below?

> +		return ret;
> +	}
> +
> +	ret = ps883x_get_vregs(retimer);
> +	if (ret)
> +		return ret;
> +
> +	retimer->xo_clk = devm_clk_get(dev, NULL);
> +	if (IS_ERR(retimer->xo_clk))
> +		return dev_err_probe(dev, PTR_ERR(retimer->xo_clk),
> +				     "failed to get xo clock\n");
> +
> +	retimer->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_ASIS);
> +	if (IS_ERR(retimer->reset_gpio))
> +		return dev_err_probe(dev, PTR_ERR(retimer->reset_gpio),
> +				     "failed to get reset gpio\n");
> +
> +	retimer->typec_switch = typec_switch_get(dev);
> +	if (IS_ERR(retimer->typec_switch))
> +		return dev_err_probe(dev, PTR_ERR(retimer->typec_switch),
> +				     "failed to acquire orientation-switch\n");
> +
> +	retimer->typec_mux = typec_mux_get(dev);
> +	if (IS_ERR(retimer->typec_mux)) {
> +		ret = dev_err_probe(dev, PTR_ERR(retimer->typec_mux),
> +				    "failed to acquire mode-mux\n");
> +		goto err_switch_put;
> +	}
> +
> +	ret = drm_aux_bridge_register(dev);
> +	if (ret)
> +		goto err_mux_put;
> +
> +	ret = clk_prepare_enable(retimer->xo_clk);
> +	if (ret) {
> +		dev_err(dev, "failed to enable XO: %d\n", ret);
> +		goto err_mux_put;
> +	}
> +
> +	ret = ps883x_enable_vregs(retimer);
> +	if (ret)
> +		goto err_clk_disable;
> +
> +	sw_desc.drvdata = retimer;
> +	sw_desc.fwnode = dev_fwnode(dev);
> +	sw_desc.set = ps883x_sw_set;
> +
> +	retimer->sw = typec_switch_register(dev, &sw_desc);
> +	if (IS_ERR(retimer->sw)) {
> +		ret = PTR_ERR(retimer->sw);
> +		dev_err(dev, "failed to register typec switch: %d\n", ret);

Maybe dev_err_probe() as above?

> +		goto err_vregs_disable;
> +	}
> +
> +	rtmr_desc.drvdata = retimer;
> +	rtmr_desc.fwnode = dev_fwnode(dev);
> +	rtmr_desc.set = ps883x_retimer_set;
> +
> +	retimer->retimer = typec_retimer_register(dev, &rtmr_desc);
> +	if (IS_ERR(retimer->retimer)) {
> +		ret = PTR_ERR(retimer->retimer);
> +		dev_err(dev, "failed to register typec retimer: %d\n", ret);

Maybe dev_err_probe() as above?

> +		goto err_switch_unregister;
> +	}
> +
> +	/* skip resetting if already configured */
> +	if (regmap_test_bits(retimer->regmap, 0x00, BIT(0)))
> +		return 0;
> +
> +	gpiod_direction_output(retimer->reset_gpio, 1);
> +
> +	/* VDD IO supply enable to reset release delay */
> +	usleep_range(4000, 14000);
> +
> +	gpiod_set_value(retimer->reset_gpio, 0);
> +
> +	/* firmware initialization delay */
> +	msleep(60);
> +
> +	return 0;
> +
> +err_switch_unregister:
> +	typec_switch_unregister(retimer->sw);
> +err_vregs_disable:
> +	ps883x_disable_vregs(retimer);
> +err_clk_disable:
> +	clk_disable_unprepare(retimer->xo_clk);
> +err_mux_put:
> +	typec_mux_put(retimer->typec_mux);
> +err_switch_put:
> +	typec_switch_put(retimer->typec_switch);
> +
> +	return ret;
> +}
> +
> +static void ps883x_retimer_remove(struct i2c_client *client)
> +{
> +	struct ps883x_retimer *retimer = i2c_get_clientdata(client);
> +
> +	typec_retimer_unregister(retimer->retimer);
> +	typec_switch_unregister(retimer->sw);
> +
> +	gpiod_set_value(retimer->reset_gpio, 1);
> +
> +	regulator_disable(retimer->vddio_supply);
> +	regulator_disable(retimer->vddat_supply);
> +	regulator_disable(retimer->vddar_supply);
> +	regulator_disable(retimer->vdd_supply);
> +	regulator_disable(retimer->vdd33_cap_supply);
> +	regulator_disable(retimer->vdd33_supply);

ps883x_disable_vregs()?

> +
> +	clk_disable_unprepare(retimer->xo_clk);
> +
> +	typec_mux_put(retimer->typec_mux);
> +	typec_switch_put(retimer->typec_switch);
> +}

...

CJ

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