From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CCD211EA7ED; Thu, 20 Feb 2025 21:52:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.11.138.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740088359; cv=none; b=dQHnLSut5l6ceTGsyJMiOy5C1XWjQLkHVKMvmuQUS8xEuUQs6vqbL4IPHX3zZv9EKtoAQinWwhXQS0ObcqgE6j8kab/1DakbQulqDI9do0AQIYWOMzXdy5tlyOsFtdpiiPATvTAwLliBYcOxYshBt624q9LhYnmiFLI9d95wgjo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740088359; c=relaxed/simple; bh=hkYlpMcQ4hjR1sAyKjYb41aAUN4ndAHMbj3Q4Y7pvjE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=aap9vwG+VuaUHn8xVFnGWEYAW9rcmC/b0Ah/IwGVBoXTV5eDL9t8fRAK+VwCrRIauznDk69SbOnd1Gciqy7XzeqaKS1MZXum2wNmBRoV37GqimJv434HW0PrAeRtXOst6vF22ua9xrDvJ8R84YWfRAGHBPlg6jLmtXAG2PmPNWI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sntech.de; spf=pass smtp.mailfrom=sntech.de; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b=ayV79j/B; arc=none smtp.client-ip=185.11.138.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sntech.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sntech.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b="ayV79j/B" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sntech.de; s=gloria202408; h=Content-Type:Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=a/47VmsCW+/vWlcxtFseGk9lbQ/93FjGlNds+Bzw9AI=; b=ayV79j/Be8/8rhQCeszDDda11d 2Yxlk8FKh6OU6gR6NVvkjKcHua7lRM6fe+mBkWsQLFGrEEKrLnHcKAT0T4FWCea5k9WKEbaS7FsrL vxHZ4rxkTHuvOR31xxiKvkjsDCsrcfyt8Bn0bHFqqUGzUFf9Qh6g9nMSftDOGUemeUcuPDI9tFSB8 cXq+Q1oe3ZujlL/FAn84pbMTVtoofn2UHSgPvR/MkSODuA5h5bTyfvIksCMQQZrSItDGwbc8+mXPQ tfQ4MzvwZNebJOM74u+dXnw2ycS5n0pt1sbYmScP8GYDlHTK7fH/mg/ERBbeTtItk2ytdxh6BjmSc bcv3p9gQ==; Received: from i53875bc0.versanet.de ([83.135.91.192] helo=diego.localnet) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1tlETB-0003Hh-NX; Thu, 20 Feb 2025 22:52:33 +0100 From: Heiko =?UTF-8?B?U3TDvGJuZXI=?= To: Linus Walleij , Bartosz Golaszewski , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Laurent Pinchart , Quentin Schulz Cc: linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Quentin Schulz Subject: Re: [PATCH 2/2] gpio: pcf857x: add support for reset-gpios on (most) PCA967x Date: Thu, 20 Feb 2025 22:52:32 +0100 Message-ID: <2590885.4XsnlVU6TS@diego> In-Reply-To: <20250220-pca976x-reset-driver-v1-2-6abbf043050e@cherry.de> References: <20250220-pca976x-reset-driver-v1-0-6abbf043050e@cherry.de> <20250220-pca976x-reset-driver-v1-2-6abbf043050e@cherry.de> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Am Donnerstag, 20. Februar 2025, 10:56:52 MEZ schrieb Quentin Schulz: > From: Quentin Schulz > > The PCA9670, PCA9671, PCA9672 and PCA9673 all have a RESETN input pin > that is used to reset the I2C GPIO expander. > > One needs to hold this pin low for at least 4us and the reset should be > finished after about 100us according to the datasheet[1]. Once the reset > is done, the "registers and I2C-bus state machine will be held in their > default state until the RESET input is once again HIGH.". > > Because the logic is reset, the latch values eventually provided in the > Device Tree via lines-initial-states property are inapplicable so they > are simply ignored if a reset GPIO is provided. > > [1] https://www.nxp.com/docs/en/data-sheet/PCA9670.pdf 8.5 and fig 22. > Signed-off-by: Quentin Schulz With the gpio-consumer fixed, reset-gpio handling works nicely on my rk3588-tiger-haikou with the DSI display overlay, so Tested-by: Heiko Stuebner