Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Sender: Guenter Roeck <groeck7@gmail.com>
Message-ID: <f3711620-d828-ed1b-f676-e5eea8fbe8a6@roeck-us.net>
Date:   Sat, 12 Aug 2023 05:33:09 -0700
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.13.0
Subject: Re: [PATCH v3 3/3] hwmon: (pmbus/tda38640) Add workaround for bug in
 SVID mode
Content-Language: en-US
To:     Naresh Solanki <naresh.solanki@9elements.com>,
        Jean Delvare <jdelvare@suse.com>,
        krzysztof.kozlowski+dt@linaro.org
Cc:     linux-hwmon@vger.kernel.org,
        Patrick Rudolph <patrick.rudolph@9elements.com>,
        linux-kernel@vger.kernel.org
References: <20230802193155.2170935-1-Naresh.Solanki@9elements.com>
 <20230802193155.2170935-3-Naresh.Solanki@9elements.com>
From:   Guenter Roeck <linux@roeck-us.net>
In-Reply-To: <20230802193155.2170935-3-Naresh.Solanki@9elements.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 8/2/23 12:31, Naresh Solanki wrote:
> From: Patrick Rudolph <patrick.rudolph@9elements.com>
> 
> TDA38640 can operate in either PMBus mode or SVID mode.
> In SVID mode, by design ENABLE pin is the only option for controlling
> the output rail.
> 
> In scenarios that utilizes the chip in SVID mode with ENABLE pin either
> grounded or tied to logic high & software control is desired then use
> dt property 'infineon,en-svid-control' to enable the below workaround.
> 
> The workaround utilizes ENABLE pin polarity flipping to control
> output rail.
> 
> If property 'infineon,en-svid-control' is specified then
> determine if chip is in SVID mode by checking BIT15 of MTP memory offset
> 0x44 as described in the datasheet.
> 
> If chip is in SVID mode then apply the workaround by
> 1. Determine EN pin level
> 2. Maps BIT7 of OPERATION(01h) to EN_PIN_POLARITY(BIT1) of
>     PB_ON_OFF_CONFIG.
> 
> Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
> Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>

For my reference:

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

We still have to wait for dt patch approval.

Guenter