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Message-ID: <a711407d-4419-4b75-99db-b8461b3bbdfe@linaro.org>
Date:   Fri, 15 Sep 2023 11:23:17 +0100
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Subject: Re: [PATCH 1/2] usb: typec: tps6598x: add reset gpio support
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To:     Javier Carrasco <javier.carrasco@wolfvision.net>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>
Cc:     linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org
References: <20230912-topic-tps6598x_reset-v1-0-78dc0bf61790@wolfvision.net>
 <20230912-topic-tps6598x_reset-v1-1-78dc0bf61790@wolfvision.net>
From:   Bryan O'Donoghue <bryan.odonoghue@linaro.org>
In-Reply-To: <20230912-topic-tps6598x_reset-v1-1-78dc0bf61790@wolfvision.net>
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On 15/09/2023 07:50, Javier Carrasco wrote:
> The TPS6598x PD controller provides an active-high hardware reset input
> that reinitializes all device settings. If it is not grounded by
> design, the driver must be able to de-assert it in order to initialize
> the device.
> 
> The PD controller is not ready for registration right after the reset
> de-assertion and a delay must be introduced in that case. According to
> TI, the delay can reach up to 1000 ms [1], which is in line with the
> experimental results obtained with a TPS65987D.
> 
> Add a GPIO descriptor for the reset signal and basic reset management
> for initialization and suspend/resume.
> 
> [1] https://e2e.ti.com/support/power-management-group/power-management/
> f/power-management-forum/1269856/tps65987d-tps65987d-reset-de-assert-
> to-normal-operation/4809389#4809389
> 
> Signed-off-by: Javier Carrasco <javier.carrasco@wolfvision.net>

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>