linux-kernel - Re: [PATCH v4 12/20] power: supply: bq25890: Support higher charging voltages through Pump Express+ protocol

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Message-ID: <YffouVvL9M4fch0I@smile.fi.intel.com>
Date:   Mon, 31 Jan 2022 15:48:41 +0200
From:   Andy Shevchenko <andriy.shevchenko@...el.com>
To:     Hans de Goede <hdegoede@...hat.com>
Cc:     "Rafael J . Wysocki" <rafael@...nel.org>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Mark Gross <markgross@...nel.org>,
        Andy Shevchenko <andy@...nel.org>,
        Wolfram Sang <wsa@...nel.org>,
        Lee Jones <lee.jones@...aro.org>,
        Sebastian Reichel <sre@...nel.org>,
        MyungJoo Ham <myungjoo.ham@...sung.com>,
        Chanwoo Choi <cw00.choi@...sung.com>,
        Ard Biesheuvel <ardb@...nel.org>, Len Brown <lenb@...nel.org>,
        linux-acpi@...r.kernel.org, Yauhen Kharuzhy <jekhor@...il.com>,
        Tsuchiya Yuto <kitakar@...il.com>,
        Fabio Aiuto <fabioaiuto83@...il.com>,
        platform-driver-x86@...r.kernel.org, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-efi@...r.kernel.org
Subject: Re: [PATCH v4 12/20] power: supply: bq25890: Support higher charging
 voltages through Pump Express+ protocol

On Sun, Jan 30, 2022 at 09:45:49PM +0100, Hans de Goede wrote:
> From: Yauhen Kharuzhy <jekhor@...il.com>
> 
> Add a "linux,pump-express-vbus-max" property which indicates if the Pump
> Express+ protocol should be used to increase the charging protocol.
> 
> If this new property is set and a DCP charger is detected then request
> a higher charging voltage through the Pump Express+ protocol.
> 
> So far this new property is only used on x86/ACPI (non devicetree) devs,
> IOW it is not used in actual devicetree files. The devicetree-bindings
> maintainers have requested properties like these to not be added to the
> devicetree-bindings, so the new property is deliberately not added
> to the existing devicetree-bindings.
> 
> Changes by Hans de Goede:
> - Port to my bq25890 patch-series + various cleanups
> - Make behavior configurable through a new "linux,pump-express-vbus-max"
>   device-property
> - Sleep 1 second before re-checking the Vbus voltage after requesting
>   it to be raised, to ensure that the ADC has time to sampled the new Vbus
> - Add VBUSV bq25890_tables[] entry and use it in bq25890_get_vbus_voltage()
> - Tweak commit message

...

> +static void bq25890_pump_express_work(struct work_struct *data)
> +{
> +	struct bq25890_device *bq =
> +		container_of(data, struct bq25890_device, pump_express_work.work);
> +	int voltage, i, ret;
> +
> +	dev_dbg(bq->dev, "Start to request input voltage increasing\n");
> +
> +	/* Enable current pulse voltage control protocol */
> +	ret = bq25890_field_write(bq, F_PUMPX_EN, 1);
> +	if (ret < 0)
> +		goto error_print;
> +
> +	for (i = 0; i < PUMP_EXPRESS_MAX_TRIES; i++) {

> +		voltage = bq25890_get_vbus_voltage(bq);
> +		if (voltage < 0)
> +			goto error_print;

It also can be (at least in align with the rest error paths)

		ret = bq25890_get_vbus_voltage(bq);
		if (ret < 0)
			goto error_print;
		voltage = ret;

followed up (but not necessarily)...

> +		dev_dbg(bq->dev, "input voltage = %d uV\n", voltage);
> +
> +		if ((voltage + PUMP_EXPRESS_VBUS_MARGIN_uV) >
> +					bq->pump_express_vbus_max)
> +			break;
> +
> +		ret = bq25890_field_write(bq, F_PUMPX_UP, 1);
> +		if (ret < 0)
> +			goto error_print;
> +
> +		/* Note a single PUMPX up pulse-sequence takes 2.1s */
> +		ret = regmap_field_read_poll_timeout(bq->rmap_fields[F_PUMPX_UP],
> +						     ret, !ret, 100000, 3000000);
> +		if (ret < 0)
> +			goto error_print;
> +
> +		/* Make sure ADC has sampled Vbus before checking again */
> +		msleep(1000);
> +	}
> +
> +	bq25890_field_write(bq, F_PUMPX_EN, 0);
> +
> +	dev_info(bq->dev, "Hi-voltage charging requested, input voltage is %d mV\n",
> +		 voltage);

> +	return;
> +error_print:

	if (ret < 0)

But it's up to you.

> +	dev_err(bq->dev, "Failed to request hi-voltage charging\n");
> +}

-- 
With Best Regards,
Andy Shevchenko