From patchwork Mon Mar 11 04:14:12 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Packham X-Patchwork-Id: 779569 Received: from gate2.alliedtelesis.co.nz (gate2.alliedtelesis.co.nz [202.36.163.20]) (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 7B46F1C3D for ; Mon, 11 Mar 2024 04:14:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.36.163.20 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710130465; cv=none; b=C7722T3tPrt2/l+zzJTLYFhRWAfT8mEZTG42yVcEBfIQE5UcaYfyWrbkQqy68J2BntYqQr0h/kmtxJaz7csw3DWYzT1e6bMe6zatwblG9UUQZIB+NpHgBQgW+QtDnFoyUfbzY/XVdwvdMEMBLBXFA6wablqHA2jRD6t4TuHlp3g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710130465; c=relaxed/simple; bh=T7eAEUhTdM+nl3KfEfDXrPZJrpXNMEqq0nIn06RMHjM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=F3avKfSLJwQVYrBQWNF+z2h5oFwAYQh6/GOQj8Tzlzi35zuw3G8+T5Ph9aBa2QP7DsEDLeLkY0kzwTY9VpOQkiWvEc1q0qCgVR3CfR7XGaU9U9eHjFX8NS663vcofNuQV6GVXIF2Acb4X3+vZ1uUDVuy+XcOOwdiU3c8SgBaOM0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=alliedtelesis.co.nz; spf=pass smtp.mailfrom=alliedtelesis.co.nz; dkim=pass (2048-bit key) header.d=alliedtelesis.co.nz header.i=@alliedtelesis.co.nz header.b=sKUizwE7; arc=none smtp.client-ip=202.36.163.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=alliedtelesis.co.nz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=alliedtelesis.co.nz Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=alliedtelesis.co.nz header.i=@alliedtelesis.co.nz header.b="sKUizwE7" Received: from svr-chch-seg1.atlnz.lc (mmarshal3.atlnz.lc [10.32.18.43]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by gate2.alliedtelesis.co.nz (Postfix) with ESMTPS id 36D1C2C02AD; Mon, 11 Mar 2024 17:14:19 +1300 (NZDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alliedtelesis.co.nz; s=mail181024; t=1710130459; bh=4+jVJ6NWBAFRBdeAjMPSWgEoWs9+6EjSCoxpfMwrwzY=; h=From:To:Cc:Subject:Date:From; b=sKUizwE7WaSi/aH0ZykgR0AgguxxlMauYoZAXoisjNa3FNLFcz5OnnGcNVmKwPl/W enHTqC7B18J/v/JnmKp2UbJ+FPXRvdN6zaQNRug+mDyODaB043Xs/ZF0uRLWPe4XyL CsyD4KmjUVmcc7kOSZyASEE/NPNrmrgXwkI5P/IhZWpF+n6oK+TJEIEk4QU8b733t9 Ps18mhO7kQn8G7QG+qEaam6WhfsrwUdg633uj6x2hBDUA6qhqpxfb3PCWgoSB/P03N f4XPLRRk408qen7QOQyyDAajwFTXvW+qabaf9b4EbUStpmKeKTmMFUTxaMnulSs+5V H3YFS2HRN3stQ== Received: from pat.atlnz.lc (Not Verified[10.32.16.33]) by svr-chch-seg1.atlnz.lc with Trustwave SEG (v8,2,6,11305) id ; Mon, 11 Mar 2024 17:14:18 +1300 Received: from chrisp-dl.ws.atlnz.lc (chrisp-dl.ws.atlnz.lc [10.33.22.30]) by pat.atlnz.lc (Postfix) with ESMTP id CA16613ED56; Mon, 11 Mar 2024 17:14:18 +1300 (NZDT) Received: by chrisp-dl.ws.atlnz.lc (Postfix, from userid 1030) id C205D2806D9; Mon, 11 Mar 2024 17:14:18 +1300 (NZDT) From: Chris Packham To: peda@axentia.se, p.zabel@pengutronix.de, krzysztof.kozlowski@linaro.org Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Chris Packham Subject: [PATCH] i2c: muxes: pca954x: Allow sharing reset GPIO Date: Mon, 11 Mar 2024 17:14:12 +1300 Message-ID: <20240311041412.3858710-1-chris.packham@alliedtelesis.co.nz> X-Mailer: git-send-email 2.43.2 Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SEG-SpamProfiler-Analysis: v=2.4 cv=BKkQr0QG c=1 sm=1 tr=0 ts=65ee851a a=KLBiSEs5mFS1a/PbTCJxuA==:117 a=K6JAEmCyrfEA:10 a=VwQbUJbxAAAA:8 a=KKAkSRfTAAAA:8 a=H3RM6WYtTQQ9Ov2Cx3cA:9 a=3ZKOabzyN94A:10 a=AjGcO6oz07-iQ99wixmX:22 a=cvBusfyB2V15izCimMoJ:22 X-SEG-SpamProfiler-Score: 0 x-atlnz-ls: pat Some hardware designs with multiple PCA954x devices use a reset GPIO connected to all the muxes. Support this configuration by making use of the reset controller framework which can deal with the shared reset GPIOs. Fall back to the old GPIO descriptor method if the reset controller framework is not enabled. Signed-off-by: Chris Packham --- Notes: This patch goes on top of Krzysztof's series adding the GPIO based reset controller[1] which will be in linux-6.9. With this I'm able to correctly describe my hardware platform in the DTS and have the resets appropriately controlled. [1] - https://lore.kernel.org/all/20240129115216.96479-1-krzysztof.kozlowski@linaro.org/ drivers/i2c/muxes/i2c-mux-pca954x.c | 46 ++++++++++++++++++++++++----- 1 file changed, 38 insertions(+), 8 deletions(-) diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c index f5dfc33b97c0..c3f4ff08ac38 100644 --- a/drivers/i2c/muxes/i2c-mux-pca954x.c +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c @@ -49,6 +49,7 @@ #include #include #include +#include #include #include #include @@ -116,6 +117,9 @@ struct pca954x { unsigned int irq_mask; raw_spinlock_t lock; struct regulator *supply; + + struct gpio_desc *reset_gpio; + struct reset_control *reset_cont; }; /* Provide specs for the MAX735x, PCA954x and PCA984x types we know about */ @@ -518,6 +522,35 @@ static int pca954x_init(struct i2c_client *client, struct pca954x *data) return ret; } +static int pca954x_get_reset(struct device *dev, struct pca954x *data) +{ + data->reset_cont = devm_reset_control_get_optional_shared(dev, NULL); + if (IS_ERR(data->reset_cont)) + return dev_err_probe(dev, PTR_ERR(data->reset_cont), + "Failed to get reset\n"); + else if (data->reset_cont) + return 0; + + /* + * fallback to legacy reset-gpios + */ + data->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); + if (IS_ERR(data->reset_gpio)) { + return dev_err_probe(dev, PTR_ERR(data->reset_gpio), + "Failed to get reset gpio"); + } + + return 0; +} + +static void pca954x_reset_deassert(struct pca954x *data) +{ + if (data->reset_cont) + reset_control_deassert(data->reset_cont); + else + gpiod_set_value_cansleep(data->reset_gpio, 0); +} + /* * I2C init/probing/exit functions */ @@ -526,7 +559,6 @@ static int pca954x_probe(struct i2c_client *client) const struct i2c_device_id *id = i2c_client_get_device_id(client); struct i2c_adapter *adap = client->adapter; struct device *dev = &client->dev; - struct gpio_desc *gpio; struct i2c_mux_core *muxc; struct pca954x *data; int num; @@ -554,15 +586,13 @@ static int pca954x_probe(struct i2c_client *client) return dev_err_probe(dev, ret, "Failed to enable vdd supply\n"); - /* Reset the mux if a reset GPIO is specified. */ - gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); - if (IS_ERR(gpio)) { - ret = PTR_ERR(gpio); + ret = pca954x_get_reset(dev, data); + if (ret) goto fail_cleanup; - } - if (gpio) { + + if (data->reset_cont || data->reset_gpio) { udelay(1); - gpiod_set_value_cansleep(gpio, 0); + pca954x_reset_deassert(data); /* Give the chip some time to recover. */ udelay(1); }