From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lf1-f49.google.com (mail-lf1-f49.google.com [209.85.167.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9C4504E50DE for ; Thu, 15 Oct 2026 11:02:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.49 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792062158; cv=none; b=ukhEOjLaRFH/4431DfChIl32SeNhVemHDseODtUEReWLuGkAgc4jkXcU9gzv2JKs7q4adq+6mJuv9nVYLyEePAsfhIlD0nDlds1ACRm5VNsYLAXIM6EaIdIB9io7e1+BmBcTc/5aZzyShUz+Y0Cj4Ay0K0KVfGN7Y0vy78DaN50= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792062158; c=relaxed/simple; bh=PydZrvt86mLHkEgBvRO47u3zMGloSwDUhiZhopFMTMw=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=s+LKMhKXp8kpZ0zwlfv1rjjjGVlsvgkwnMUO10Cf2e9kTsE2m+T65jioSnVwzB4nrwy1FehtiqybDIGl1mV2/RCjSIj1Tg10umms5xV0SB7UIK43RgF9L6UtPIjUn+o8B8z5viwKsaxkp2A/cSrzrY2QzWWwee3Tn5qy9QczR8s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=fodO9+L4; arc=none smtp.client-ip=209.85.167.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fodO9+L4" Received: by mail-lf1-f49.google.com with SMTP id 2adb3069b0e04-5be3db57938so446275e87.0 for ; Thu, 15 Oct 2026 04:02:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1792062155; x=1792666955; darn=vger.kernel.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :content-type:mime-version:subject:date:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=y+QorVKMJYnLkrPsErRwwCkJsDT8x7ezxaNNbTsRw5I=; b=fodO9+L4ZDBTEfxQ7fG3fDTw2X8W79kcUUWjHL13rGT1fjX00QfO6rH7CdLYIurne8 bfLcr6sxHGKJInRAemP3Wj/pqAlRTLO45GU7WmvklrSZE90PagRl7OmbeF/6rSuHEk+R UATHTJ1WokDJtztfaX4anWlcO4MosbvKyDcdYB3DFVD/yHZoZDNzq9uJxwFTbiQNPWCo rW+kHEr0v1pk5WNfQTRFMQ1ZurMkoMZy2W4E6ks12wTrCrI3UGjc4u89kexVfsK165ZS QwYKZe1xnqef4PqJzuTwPLjN2Wt7J3zTBp9UcHexn5pfe+2uZLDDeBmLum68yfGsbpdK bgMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792062155; x=1792666955; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :content-type:mime-version:subject:date:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=y+QorVKMJYnLkrPsErRwwCkJsDT8x7ezxaNNbTsRw5I=; b=uIHGdidC3LNDUN79R26wKmidNxVvemo5Qls0t8SE+ex3kx3y9htubr5yGUozKoPjAZ hxylOS1s1ck1RPjt5/w9ycyh7GZfXbfLtULV9jYQlbhfSCf3jbGIQrm8hO/NvLN51pvX ppR8r5TmyqsT4zjGutXncU8/5ihP33r57H1vMhMk2q8Aa36RvsMRSNjDmvGjOselxlN2 iyxyHMRXwRIfkVkxdMmHlI0XbSqyk4+8t/gj6HG7lJqn0IOj2BWidwQ4LX4R1wUtD91J efDRkygm4wM6XboWgK4s+XaW5FJJVsk0D4yuBLjZY/kHpoOgiY6hU0T66AVXeyM7l4eN +Iag== X-Forwarded-Encrypted: i=1; AKwUvBxs4IW42UQR8VNp8wCO8nKKImq+RCkH548VeGawvtcMfiO8i55bHuv7h7t74CFMpi6n/J2dzGe6mpCB8jc=@vger.kernel.org X-Gm-Message-State: AFq9FYJV5KJhBEw+AiCI8uLoqCjl6V9L7AeuvpRiqgW3KUri3B/ArRHq oiSbJDoH9CqzMGOlFASkjhNssFbH//w7vrWgeCaO3u9sZc8COxBgHWL+ X-Gm-Gg: AYBFou0ipXiMrhnDHWdmLoUVuQMWBgiuvINN5RB1bx5d+qELOZaotDOEXKMCYLSv0oD H/f/LrYZElBcyS1QMGoZ4zuSd4TI5EG750oL3fnmq2ODHVbFCu6N0PvrRYrOQ6T2dREQD8pMv89 eunQUjWP0Hv5kgR/3Mt6i6qzGxDNw1SEp29w0n8knJoqGim8vGbQrzvm9lrJgxUocYa4jC75sWN B8zIFt+qXHACs9vRKYFJ+wHHC7p4ujezS4mYza1Dx2Znl+5OcMxY8BHjd5mlpNv/upl8pRvkuRd FpyuolFachTqbsPhEEFMNUVQNqi2ZeEAnDiezuu7AbJddHAeHp7JTe1Ja3mwll4YECS+WE3dowQ 8AZpmYQacEYxhmS3bPuC05wIByUxN7XN/WYa3a3PaGJv8TWT9sfiTi6q2i+IEeBms0lSdZ88WZ8 avZb+ariZJQmp8svUJMKcaNLuB3mUs5QpKmtF5w+RRVyE34obxW6PHb7By8UPuSM/MW0iTc8wHc 2t/uxjh7zgl151xrz8Fk8K3NoCjSitpcFw71yBGL+hrri5f+D/+CmlGp9Kj5w== X-Received: by 2002:a05:6512:4404:b0:5b8:999f:718b with SMTP id 2adb3069b0e04-5bcea0c31b7mr4505668e87.12.1792062154506; Thu, 15 Oct 2026 04:02:34 -0700 (PDT) Received: from [192.168.1.135] (81-229-40-193-no2450.tbcn.telia.com. [81.229.40.193]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-5be3739b5d1sm905465e87.22.2026.10.15.04.02.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Oct 2026 04:02:33 -0700 (PDT) From: Marcus Folkesson Date: Thu, 15 Oct 2026 13:01:49 +0200 Subject: [PATCH v13 2/8] i2c: mux: add idle_state property to i2c_mux_core Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261015-i2c-mux-v13-2-778a12cfe93b@gmail.com> References: <20261015-i2c-mux-v13-0-778a12cfe93b@gmail.com> In-Reply-To: <20261015-i2c-mux-v13-0-778a12cfe93b@gmail.com> To: Wolfram Sang , Michael Hennerich , Bartosz Golaszewski , Andi Shyti , Andy Shevchenko , Bartosz Golaszewski , Peter Rosin , Peter Rosin Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Marcus Folkesson X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=3427; i=marcus.folkesson@gmail.com; h=from:subject:message-id; bh=PydZrvt86mLHkEgBvRO47u3zMGloSwDUhiZhopFMTMw=; b=owEBbQKS/ZANAwAKAYiATm9ZXVIyAcsmYgBq0LKoIcY9A9AvCh5SSkNgUH2sA6MzgWGCpMpJD E06xQD8236JAjMEAAEKAB0WIQQFUaLotmy1TWTBLGWIgE5vWV1SMgUCatCyqAAKCRCIgE5vWV1S MlhuD/sHP9hzPuDbWoiGI5oiApoeF7AO5OTE+Ih2rYrBbQSQTnM3aUCaCY9EoRwpHw7s4NxTcDc Ng8jOu840EZ6aLEei9FlV0T3ibI65xxQ8FDrACZzOc8t26wIT3Pp3I3B/kEhhJ7IjedJxnxwJ2M XMdcJtmJuY4LkuGyYg6qs+2jtObGtKHZyjS+948NTUXXOhur05lfDw0ItuT/ipgsDLS3ARS636k jUIl9DL4dAZcBVQAySS4dqZNiEhzHZ4oQwKrnebhnggOEcqHM/kZPiT0ixJzBIDDlHDifHnHVw0 v4AwNrmX5hHJsL9EXKyRssYut5636uyoCORAavn1lfBJTul8ldre6RrzJe8Xim8tn2TUENm7pxx IhC0pTYYS5+5lVc5NWAhh1Em7v8Tbcyi1DTdD6buIF/uet2V2I/DFyyfeVbnD6O+7lmBLfsqKSn b6ZSzblNKKNWlDav3tFH7nGNOufo89epKLFWQbPPLrUIOV1XPCez9vUNeRvsphkJ1H3bfBQE62B /+HzmxudhAkV6ydctNGhcm+ZI6aHHhnLmjuSO2OWCVifk7Kz03kLSFDiGXKUX9TVTLumWGRQ2dp 9L5yX6Gim8QwZx91chiubHWKYZh78CkloOtBj8b/082kwHMZo0Bf0h8fsVdnuygz/XmESsx4TE0 LHaiyT3mh9pvkgQ== X-Developer-Key: i=marcus.folkesson@gmail.com; a=openpgp; fpr=AB91D46C7E0F6E6FB2AB640EC0FE25D598F6C127 Muxes treat their channels differently when idle. Let the mux core have this information to make it available for internal use. Possible idle states are: - I2C_MUX_IDLE_AS_IS: Leave channels as is when idle - I2C_MUX_IDLE_DISCONNECT: Disconnect channel (set HiZ when idle) - I2C_MUX_IDLE_UNKNOWN: Unknown idle state - : Enable channel n (starting from 0) when idle" Default value is set to I2C_MUX_IDLE_UNKNOWN. Reviewed-by: Andy Shevchenko Signed-off-by: Marcus Folkesson --- drivers/i2c/i2c-mux.c | 1 + include/linux/i2c-mux.h | 57 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 58 insertions(+) diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c index 53428098ddc7..94cc019b222f 100644 --- a/drivers/i2c/i2c-mux.c +++ b/drivers/i2c/i2c-mux.c @@ -248,6 +248,7 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent, muxc->select = select; muxc->deselect = deselect; muxc->max_adapters = max_adapters; + muxc->idle_state = I2C_MUX_IDLE_UNKNOWN; return muxc; } diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h index 1784ac7afb11..17690f4f0dbe 100644 --- a/include/linux/i2c-mux.h +++ b/include/linux/i2c-mux.h @@ -14,6 +14,11 @@ #ifdef __KERNEL__ #include +#include + +#define I2C_MUX_IDLE_AS_IS (-1) +#define I2C_MUX_IDLE_DISCONNECT (-2) +#define I2C_MUX_IDLE_UNKNOWN (-3) struct i2c_mux_core { struct i2c_adapter *parent; @@ -22,6 +27,18 @@ struct i2c_mux_core { unsigned int arbitrator:1; unsigned int gate:1; + /* + * The mux state used by the driver when idle. + * Possible idle states are: + * - I2C_MUX_IDLE_AS_IS: Leave channels as is when idle + * - I2C_MUX_IDLE_DISCONNECT: Disconnect channel (set HiZ when idle) + * - I2C_MUX_IDLE_UNKNOWN: Unknown idle state + * - : Enable channel n (starting from 0) when idle" + * + * Default value is set to I2C_MUX_IDLE_UNKNOWN. + */ + int idle_state; + void *priv; int (*select)(struct i2c_mux_core *, u32 chan_id); @@ -38,6 +55,46 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent, int (*select)(struct i2c_mux_core *, u32), int (*deselect)(struct i2c_mux_core *, u32)); +static inline int i2c_mux_set_idle_state(struct i2c_mux_core *muxc, int state) +{ + switch (state) { + case I2C_MUX_IDLE_AS_IS: + case I2C_MUX_IDLE_UNKNOWN: + for (int i = 0; i < muxc->num_adapters; i++) { + /* + * idle_state is incompatible with channels that have a + * different clock frequency than the parent adapter. + */ + if (muxc->adapter[i]->clock_Hz != muxc->parent->clock_Hz) + return -EINVAL; + } + break; + + case I2C_MUX_IDLE_DISCONNECT: + break; + + default: + if (state < 0 || state >= muxc->num_adapters) + return -EINVAL; + + /* + * idle_state cannot select a channel with a different clock + * frequency than the parent adapter. + */ + if (muxc->adapter[state]->clock_Hz != muxc->parent->clock_Hz) + return -EINVAL; + break; + } + + muxc->idle_state = state; + return 0; +} + +static inline int i2c_mux_idle_state(struct i2c_mux_core *muxc) +{ + return muxc->idle_state; +} + /* flags for i2c_mux_alloc */ #define I2C_MUX_LOCKED BIT(0) #define I2C_MUX_ARBITRATOR BIT(1) -- 2.55.0