linux-kernel - Re: [PATCH 11/13] i2c: cht-wc: Add support for devices using a bq25890 charger

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Message-ID: <bed46b1b-eebe-4b61-1470-6f8428208a7a@redhat.com>
Date:   Mon, 8 Nov 2021 17:03:33 +0100
From:   Hans de Goede <hdegoede@...hat.com>
To:     Wolfram Sang <wsa@...-dreams.de>,
        Mark Gross <markgross@...nel.org>,
        Andy Shevchenko <andy@...radead.org>,
        Sebastian Reichel <sre@...nel.org>,
        MyungJoo Ham <myungjoo.ham@...sung.com>,
        Chanwoo Choi <cw00.choi@...sung.com>,
        Ard Biesheuvel <ardb@...nel.org>,
        Yauhen Kharuzhy <jekhor@...il.com>,
        Tsuchiya Yuto <kitakar@...il.com>,
        platform-driver-x86@...r.kernel.org, linux-i2c@...r.kernel.org,
        linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-efi@...r.kernel.org
Subject: Re: [PATCH 11/13] i2c: cht-wc: Add support for devices using a
 bq25890 charger

Hi,

On 10/31/21 18:58, Wolfram Sang wrote:
> On Sat, Oct 30, 2021 at 08:28:11PM +0200, Hans de Goede wrote:
>> The i2c-controller on the Cherry Trail - Whiskey Cove PMIC is special
>> in that it is always connected to the I2C charger IC of the board on
>> which the PMIC is used; and the charger IC is not described in ACPI,
>> so the i2c-cht-wc code needs to instantiate an i2c-client for it itself.
>>
>> So far there has been a rudimentary check to make sure the ACPI tables
>> are at least somewhat as expected by checking for the presence of an
>> INT33FE device and sofar the code has assumed that if this INT33FE
>> device is present that the used charger then is a bq24290i.
>>
>> But some boards with an INT33FE device in their ACPI tables use a
>> different charger IC and some boards don't have an INT33FE device at all.
>>
>> Since the information about the used charger + fuel-gauge + other chips is
>> necessary in other places too, the kernel now adds a "intel,cht-wc-setup"
>> string property to the Whiskey Cove PMIC i2c-client based on DMI matching,
>> which reliably describes the board's setup of the PMIC.
>>
>> Switch to using the "intel,cht-wc-setup" property and add support for
>> instantiating an i2c-client for either a bq24292i or a bq25890 charger.
>>
>> This has been tested on a GPD pocket (which uses the old bq24292i setup)
>> and on a Xiaomi Mi Pad 2 with a bq25890 charger.
>>
>> Signed-off-by: Hans de Goede <hdegoede@...hat.com>
> 
> In general, fine with me from the I2C side:
> 
> Acked-by: Wolfram Sang <wsa@...nel.org>

Thank you for v2 I've refactored things a bit, enough that I'm going
to drop your Ack, sorry.

>> +	else if (!strcmp(str, "bq24292i,max17047,fusb302,pi3usb30532"))
>> +		board_info = &bq24190_board_info;
>> +	else if (!strcmp(str, "bq25890,bq27520"))
>> +		board_info = &bq25890_board_info;
> 
> Very minor nit: I prefer 'strcmp() == 0' because the above could be read
> as 'if not strcmp()' which is sadly misleading. But I am not strict with
> it.

All the strcmp-s are gone in the refactored version.

Regards,

Hans