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([2a02:578:85c6:1101:1ab9:445:1169:11e3]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4887a630922sm107306355e9.0.2026.03.31.16.05.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 31 Mar 2026 16:05:58 -0700 (PDT) Message-ID: <855078f2-1b43-436e-b06e-4fa38782d2a3@mind.be> Date: Wed, 1 Apr 2026 01:05:58 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2 v2] spi: add SPI_MOSI_IDLE_LOW support from device tree To: Marcelo Schmitt Cc: broonie@kernel.org, linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260329125725.2984756-1-charles-antoine.couret@mind.be> <3a9dc8f9-0588-44ee-97ba-3a248d4f65dd@mind.be> Content-Language: fr-FR, en-NZ From: Couret Charles-Antoine In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hi Marcelo, Le 29/03/26 à 21:29, Marcelo Schmitt a écrit : >> For example we used that to communicate with TI DAC161P997 device, where >> "IDLE low" setting can be used to detect when the device is really powered >> or not. But this is an optional setting, this option does not affect the >> rest of the driver. > Can't that be done with the existing support for idle modes? E.g. > spi->mode |= SPI_MOSI_IDLE_LOW; > ret = spi_setup(spi); > if (ret < 0) { > /* No controller MOSI idle low support. */ > /* Can't verify device is powered on. Return or do something else. */ > } > /* MOSI idle low support. Verify the device is powered on. */ > This means we need to hardcode the behaviour in the driver or to add an extra setting if we don't especially want to enable this. I agree with you: there is always a way to deal with it without this property in the device tree. However, I don't think this means the property in the device tree is irrelevant. Regards, -- Charles-Antoine Couret Embedded Software Developer +32 488 27 56 40 Website • LinkedIn • Newslette r