From patchwork Wed Jan 8 16:14:07 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Romain Gantois X-Patchwork-Id: 855786 Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net [217.70.183.195]) (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 4DE821FC7E0; Wed, 8 Jan 2025 16:14:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.195 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736352862; cv=none; b=CMz3eKVaKMg9V6rsmwYUpqE8zNTL/Fe8/b98LxdQb9nMz8vl3XIgYE2fMXvucr/VB6SgoXwdg3q5TAHvdOx/zaBLYPR2U/DMDHNiVMsrtw57Mz08fgwUXlnpzBUYeXDPBpp6cjmQB7CyRp8bOhBIpnqbdGECNo633uzfufH6FsI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736352862; c=relaxed/simple; bh=5KtR9LZNxsEQKyvr75n3BfgXr66S0XcEeFw9nqt2874=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=qBVnhA8fLRA49lm/1mMn4gcuCz9QHGubZfvA+Tc0jlVZowmuSiMRyiw1GRVPZVCiDs4Z/52YKrzlA1oKA3gO4JSWEjtpuK4wF/DBf+sO9+pai/CnLrC5rUdIJ35Ml7JJFAX7jw/6vmGPVaqDd6uRmmww04RaunSn6PBUYNE68LU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=kB7K/75t; arc=none smtp.client-ip=217.70.183.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="kB7K/75t" Received: by mail.gandi.net (Postfix) with ESMTPSA id 9BADC60014; Wed, 8 Jan 2025 16:14:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1736352856; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hqgEz5Scvwb7Wt/vHXsm0IRP+QaTyrHu5MCvjQrUT/U=; b=kB7K/75tLJaS+55ETt5mHyE933Ux2HLvZS/dv5WSn00cVOOy+CKCAjXoEdDF8OVC7heNAy cxIOwdUs6lq7j8fUwh/mewCI/DKhKsHw7AW/8gUrICCfBO8/DskOCmUi5gNhQId+n1/rvB VvPf7O6ElH9WALdLg0jhpvVRMsNjKeyHTprH6fsh4uuyabH0tKV89O46PijDDWE0AUJGIw 6tfXk0re0waVOw7H/mFV/TbeJR8RDWh7wZdGBY3HoifE7B6flsbo9wNdskyiEXBh6iJp6k P6vx2iGecPN1lTW5RbjUF1uALvc3veWTzUPiNVz/uedTCY5Eg4Vnbb3TzEaqcA== From: Romain Gantois Date: Wed, 08 Jan 2025 17:14:07 +0100 Subject: [PATCH v5 6/9] i2c: rename field 'alias_list' of struct i2c_atr_chan to 'alias_pairs' Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250108-fpc202-v5-6-a439ab999d5a@bootlin.com> References: <20250108-fpc202-v5-0-a439ab999d5a@bootlin.com> In-Reply-To: <20250108-fpc202-v5-0-a439ab999d5a@bootlin.com> To: Wolfram Sang , Tomi Valkeinen , Luca Ceresoli , Andi Shyti , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Derek Kiernan , Dragan Cvetic , Arnd Bergmann , Greg Kroah-Hartman , Mauro Carvalho Chehab , Linus Walleij , Bartosz Golaszewski Cc: Thomas Petazzoni , Kory Maincent , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-media@vger.kernel.org, linux-gpio@vger.kernel.org, Romain Gantois X-Mailer: b4 0.14.2 X-GND-Sasl: romain.gantois@bootlin.com The "alias_list" field of struct i2c_atr_chan describes translation table entries programmed in the ATR channel. This terminology will become more confusing when per-channel alias pool support is introduced, as struct i2c_atr_chan will gain a new field called "alias_pool", which will describe aliases which are available to the ATR channel. Rename the "alias_list" field to "alias_pairs" to clearly distinguish it from the future "alias_pool" field. No functional change is intended. Signed-off-by: Romain Gantois --- drivers/i2c/i2c-atr.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/i2c/i2c-atr.c b/drivers/i2c/i2c-atr.c index 019089346ce4622e46a4802c990cdacd24d47734..8fb3d66d87732b769429b708ba45e16c48f33093 100644 --- a/drivers/i2c/i2c-atr.c +++ b/drivers/i2c/i2c-atr.c @@ -56,7 +56,7 @@ struct i2c_atr_alias_pool { * @adap: The &struct i2c_adapter for the channel * @atr: The parent I2C ATR * @chan_id: The ID of this channel - * @alias_list: List of @struct i2c_atr_alias_pair containing the + * @alias_pairs: List of @struct i2c_atr_alias_pair containing the * assigned aliases * @orig_addrs_lock: Mutex protecting @orig_addrs * @orig_addrs: Buffer used to store the original addresses during transmit @@ -67,7 +67,7 @@ struct i2c_atr_chan { struct i2c_atr *atr; u32 chan_id; - struct list_head alias_list; + struct list_head alias_pairs; /* Lock orig_addrs during xfer */ struct mutex orig_addrs_lock; @@ -192,7 +192,7 @@ static int i2c_atr_map_msgs(struct i2c_atr_chan *chan, struct i2c_msg *msgs, for (i = 0; i < num; i++) { chan->orig_addrs[i] = msgs[i].addr; - c2a = i2c_atr_find_mapping_by_addr(&chan->alias_list, + c2a = i2c_atr_find_mapping_by_addr(&chan->alias_pairs, msgs[i].addr); if (!c2a) { dev_err(atr->dev, "client 0x%02x not mapped!\n", @@ -262,7 +262,7 @@ static int i2c_atr_smbus_xfer(struct i2c_adapter *adap, u16 addr, struct i2c_adapter *parent = atr->parent; struct i2c_atr_alias_pair *c2a; - c2a = i2c_atr_find_mapping_by_addr(&chan->alias_list, addr); + c2a = i2c_atr_find_mapping_by_addr(&chan->alias_pairs, addr); if (!c2a) { dev_err(atr->dev, "client 0x%02x not mapped!\n", addr); return -ENXIO; @@ -380,7 +380,7 @@ static int i2c_atr_attach_addr(struct i2c_adapter *adapter, c2a->addr = addr; c2a->alias = alias; - list_add(&c2a->node, &chan->alias_list); + list_add(&c2a->node, &chan->alias_pairs); return 0; @@ -401,7 +401,7 @@ static void i2c_atr_detach_addr(struct i2c_adapter *adapter, atr->ops->detach_addr(atr, chan->chan_id, addr); - c2a = i2c_atr_find_mapping_by_addr(&chan->alias_list, addr); + c2a = i2c_atr_find_mapping_by_addr(&chan->alias_pairs, addr); if (!c2a) { /* This should never happen */ dev_warn(atr->dev, "Unable to find address mapping\n"); @@ -621,7 +621,7 @@ int i2c_atr_add_adapter(struct i2c_atr *atr, u32 chan_id, chan->atr = atr; chan->chan_id = chan_id; - INIT_LIST_HEAD(&chan->alias_list); + INIT_LIST_HEAD(&chan->alias_pairs); mutex_init(&chan->orig_addrs_lock); snprintf(chan->adap.name, sizeof(chan->adap.name), "i2c-%d-atr-%d", From patchwork Wed Jan 8 16:14:08 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Romain Gantois X-Patchwork-Id: 855785 Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net [217.70.183.195]) (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 7F3FF1FECAB; Wed, 8 Jan 2025 16:14:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.195 ARC-Seal: i=1; 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dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="jGX4jYqg" Received: by mail.gandi.net (Postfix) with ESMTPSA id BDCBC60015; Wed, 8 Jan 2025 16:14:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1736352857; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Gm2mlGT3zLjb3hb0z60bmxq63Fwc4TnOx2PJk5H4Y+A=; b=jGX4jYqgiLcLz4r0Ed3Hzjn4CfqNLwuTU5sxe3lxWvYr1LqMEb03WpRjwNlZyyh/kkFx0R 6EOiyqjivxhaRZEC9E2uxS1f4tD4+zZaL4771c8BmLhj2PFF+u3dsUbvv8+MddDr1lQnrt ULmXdO6B6hGWGFgsS8dHp1bp7lhemJEMF3QsZ2jAw4lwyeCJmR/flYQ3XzuQG6XjQsbwRU WXNuS28WPCFVGERnmBZ/9RVPKlzfWlRe/JnyDe55x3HIprwnpabECx/RlbE+NtKvTK64DW 0gaP0GNfvjgabHj6YbuO3ZeajXP4ITIUej8nvpYW1Fu6Cgu9C7n7WwjkSfttSA== From: Romain Gantois Date: Wed, 08 Jan 2025 17:14:08 +0100 Subject: [PATCH v5 7/9] i2c: support per-channel ATR alias pools Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250108-fpc202-v5-7-a439ab999d5a@bootlin.com> References: <20250108-fpc202-v5-0-a439ab999d5a@bootlin.com> In-Reply-To: <20250108-fpc202-v5-0-a439ab999d5a@bootlin.com> To: Wolfram Sang , Tomi Valkeinen , Luca Ceresoli , Andi Shyti , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Derek Kiernan , Dragan Cvetic , Arnd Bergmann , Greg Kroah-Hartman , Mauro Carvalho Chehab , Linus Walleij , Bartosz Golaszewski Cc: Thomas Petazzoni , Kory Maincent , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-media@vger.kernel.org, linux-gpio@vger.kernel.org, Romain Gantois X-Mailer: b4 0.14.2 X-GND-Sasl: romain.gantois@bootlin.com Some I2C address translators (ATRs) assign each of their remote peripheral aliases to a specific channel. To properly handle these devices, add support for having separate alias pools for each ATR channel. This is achieved by allowing callers of i2c_atr_add_adapter to pass an optional alias list. If present, this list will be used to populate the channel's alias pool. Otherwise, the common alias pool will be used. Signed-off-by: Romain Gantois --- drivers/i2c/i2c-atr.c | 74 ++++++++++++++++++++++++++++++------------- drivers/media/i2c/ds90ub913.c | 9 ++++-- drivers/media/i2c/ds90ub953.c | 9 ++++-- include/linux/i2c-atr.h | 34 ++++++++++++++------ 4 files changed, 91 insertions(+), 35 deletions(-) diff --git a/drivers/i2c/i2c-atr.c b/drivers/i2c/i2c-atr.c index 8fb3d66d87732b769429b708ba45e16c48f33093..6c0cf46a90da61b8a418b71e852ead5f1afa1d36 100644 --- a/drivers/i2c/i2c-atr.c +++ b/drivers/i2c/i2c-atr.c @@ -37,6 +37,7 @@ struct i2c_atr_alias_pair { /** * struct i2c_atr_alias_pool - Pool of client aliases available for an ATR. * @size: Total number of aliases + * @shared: Indicates if this alias pool is shared by multiple channels * * @lock: Lock protecting @aliases and @use_mask * @aliases: Array of aliases, must hold exactly @size elements @@ -44,6 +45,7 @@ struct i2c_atr_alias_pair { */ struct i2c_atr_alias_pool { size_t size; + bool shared; /* Protects aliases and use_mask */ spinlock_t lock; @@ -58,6 +60,8 @@ struct i2c_atr_alias_pool { * @chan_id: The ID of this channel * @alias_pairs: List of @struct i2c_atr_alias_pair containing the * assigned aliases + * @alias_pool: Pool of available client aliases + * * @orig_addrs_lock: Mutex protecting @orig_addrs * @orig_addrs: Buffer used to store the original addresses during transmit * @orig_addrs_size: Size of @orig_addrs @@ -68,6 +72,7 @@ struct i2c_atr_chan { u32 chan_id; struct list_head alias_pairs; + struct i2c_atr_alias_pool *alias_pool; /* Lock orig_addrs during xfer */ struct mutex orig_addrs_lock; @@ -84,7 +89,7 @@ struct i2c_atr_chan { * @algo: The &struct i2c_algorithm for adapters * @lock: Lock for the I2C bus segment (see &struct i2c_lock_operations) * @max_adapters: Maximum number of adapters this I2C ATR can have - * @alias_pool: Pool of available client aliases + * @alias_pool: Optional common pool of available client aliases * @i2c_nb: Notifier for remote client add & del events * @adapter: Array of adapters */ @@ -107,7 +112,7 @@ struct i2c_atr { struct i2c_adapter *adapter[] __counted_by(max_adapters); }; -static struct i2c_atr_alias_pool *i2c_atr_alloc_alias_pool(size_t num_aliases) +static struct i2c_atr_alias_pool *i2c_atr_alloc_alias_pool(size_t num_aliases, bool shared) { struct i2c_atr_alias_pool *alias_pool; int ret; @@ -130,6 +135,8 @@ static struct i2c_atr_alias_pool *i2c_atr_alloc_alias_pool(size_t num_aliases) goto err_free_aliases; } + alias_pool->shared = shared; + spin_lock_init(&alias_pool->lock); return alias_pool; @@ -357,7 +364,7 @@ static int i2c_atr_attach_addr(struct i2c_adapter *adapter, u16 alias; int ret; - ret = i2c_atr_reserve_alias(atr->alias_pool); + ret = i2c_atr_reserve_alias(chan->alias_pool); if (ret < 0) { dev_err(atr->dev, "failed to find a free alias\n"); return ret; @@ -387,7 +394,7 @@ static int i2c_atr_attach_addr(struct i2c_adapter *adapter, err_free: kfree(c2a); err_release_alias: - i2c_atr_release_alias(atr->alias_pool, alias); + i2c_atr_release_alias(chan->alias_pool, alias); return ret; } @@ -408,7 +415,7 @@ static void i2c_atr_detach_addr(struct i2c_adapter *adapter, return; } - i2c_atr_release_alias(atr->alias_pool, c2a->alias); + i2c_atr_release_alias(chan->alias_pool, c2a->alias); dev_dbg(atr->dev, "chan%u: detached alias 0x%02x from addr 0x%02x\n", @@ -469,16 +476,20 @@ static int i2c_atr_parse_alias_pool(struct i2c_atr *atr) u32 *aliases32; int ret; - ret = fwnode_property_count_u32(dev_fwnode(dev), "i2c-alias-pool"); - if (ret < 0) { - dev_err(dev, "Failed to count 'i2c-alias-pool' property: %d\n", - ret); - return ret; - } + if (!fwnode_property_present(dev_fwnode(dev), "i2c-alias-pool")) { + num_aliases = 0; + } else { + ret = fwnode_property_count_u32(dev_fwnode(dev), "i2c-alias-pool"); + if (ret < 0) { + dev_err(dev, "Failed to count 'i2c-alias-pool' property: %d\n", + ret); + return ret; + } - num_aliases = ret; + num_aliases = ret; + } - alias_pool = i2c_atr_alloc_alias_pool(num_aliases); + alias_pool = i2c_atr_alloc_alias_pool(num_aliases, true); if (IS_ERR(alias_pool)) { ret = PTR_ERR(alias_pool); dev_err(dev, "Failed to allocate alias pool, err %d\n", ret); @@ -592,15 +603,15 @@ void i2c_atr_delete(struct i2c_atr *atr) } EXPORT_SYMBOL_NS_GPL(i2c_atr_delete, I2C_ATR); -int i2c_atr_add_adapter(struct i2c_atr *atr, u32 chan_id, - struct device *adapter_parent, - struct fwnode_handle *bus_handle) +int i2c_atr_add_adapter(struct i2c_atr *atr, struct i2c_atr_adap_desc *desc) { + struct fwnode_handle *bus_handle = desc->bus_handle; struct i2c_adapter *parent = atr->parent; + char symlink_name[ATR_MAX_SYMLINK_LEN]; struct device *dev = atr->dev; + u32 chan_id = desc->chan_id; struct i2c_atr_chan *chan; - char symlink_name[ATR_MAX_SYMLINK_LEN]; - int ret; + int ret, idx; if (chan_id >= atr->max_adapters) { dev_err(dev, "No room for more i2c-atr adapters\n"); @@ -616,8 +627,8 @@ int i2c_atr_add_adapter(struct i2c_atr *atr, u32 chan_id, if (!chan) return -ENOMEM; - if (!adapter_parent) - adapter_parent = dev; + if (!desc->parent) + desc->parent = dev; chan->atr = atr; chan->chan_id = chan_id; @@ -629,7 +640,7 @@ int i2c_atr_add_adapter(struct i2c_atr *atr, u32 chan_id, chan->adap.owner = THIS_MODULE; chan->adap.algo = &atr->algo; chan->adap.algo_data = chan; - chan->adap.dev.parent = adapter_parent; + chan->adap.dev.parent = desc->parent; chan->adap.retries = parent->retries; chan->adap.timeout = parent->timeout; chan->adap.quirks = parent->quirks; @@ -656,13 +667,26 @@ int i2c_atr_add_adapter(struct i2c_atr *atr, u32 chan_id, fwnode_handle_put(atr_node); } + if (desc->num_aliases > 0) { + chan->alias_pool = i2c_atr_alloc_alias_pool(desc->num_aliases, false); + if (IS_ERR(chan->alias_pool)) { + ret = PTR_ERR(chan->alias_pool); + goto err_fwnode_put; + } + + for (idx = 0; idx < desc->num_aliases; idx++) + chan->alias_pool->aliases[idx] = desc->aliases[idx]; + } else { + chan->alias_pool = atr->alias_pool; + } + atr->adapter[chan_id] = &chan->adap; ret = i2c_add_adapter(&chan->adap); if (ret) { dev_err(dev, "failed to add atr-adapter %u (error=%d)\n", chan_id, ret); - goto err_fwnode_put; + goto err_free_alias_pool; } snprintf(symlink_name, sizeof(symlink_name), "channel-%u", @@ -679,6 +703,9 @@ int i2c_atr_add_adapter(struct i2c_atr *atr, u32 chan_id, return 0; +err_free_alias_pool: + if (!chan->alias_pool->shared) + i2c_atr_free_alias_pool(chan->alias_pool); err_fwnode_put: fwnode_handle_put(dev_fwnode(&chan->adap.dev)); mutex_destroy(&chan->orig_addrs_lock); @@ -711,6 +738,9 @@ void i2c_atr_del_adapter(struct i2c_atr *atr, u32 chan_id) i2c_del_adapter(adap); + if (!chan->alias_pool->shared) + i2c_atr_free_alias_pool(chan->alias_pool); + atr->adapter[chan_id] = NULL; fwnode_handle_put(fwnode); diff --git a/drivers/media/i2c/ds90ub913.c b/drivers/media/i2c/ds90ub913.c index 8eed4a200fd89b5af1fc4578cb865bf1408acd76..1bb4efa44ede1267e15d29e0ce3965372bf3bb89 100644 --- a/drivers/media/i2c/ds90ub913.c +++ b/drivers/media/i2c/ds90ub913.c @@ -656,6 +656,7 @@ static int ub913_i2c_master_init(struct ub913_data *priv) static int ub913_add_i2c_adapter(struct ub913_data *priv) { struct device *dev = &priv->client->dev; + struct i2c_atr_adap_desc desc = { }; struct fwnode_handle *i2c_handle; int ret; @@ -663,8 +664,12 @@ static int ub913_add_i2c_adapter(struct ub913_data *priv) if (!i2c_handle) return 0; - ret = i2c_atr_add_adapter(priv->plat_data->atr, priv->plat_data->port, - dev, i2c_handle); + desc.chan_id = priv->plat_data->port; + desc.parent = dev; + desc.bus_handle = i2c_handle; + desc.num_aliases = 0; + + ret = i2c_atr_add_adapter(priv->plat_data->atr, &desc); fwnode_handle_put(i2c_handle); diff --git a/drivers/media/i2c/ds90ub953.c b/drivers/media/i2c/ds90ub953.c index 8b028a84f5bc7fd2af5c95115dcb6a7c1dadc821..013e6b5b9fbddb00d6d859972b63cf905ee988c7 100644 --- a/drivers/media/i2c/ds90ub953.c +++ b/drivers/media/i2c/ds90ub953.c @@ -1100,6 +1100,7 @@ static int ub953_register_clkout(struct ub953_data *priv) static int ub953_add_i2c_adapter(struct ub953_data *priv) { struct device *dev = &priv->client->dev; + struct i2c_atr_adap_desc desc = { }; struct fwnode_handle *i2c_handle; int ret; @@ -1107,8 +1108,12 @@ static int ub953_add_i2c_adapter(struct ub953_data *priv) if (!i2c_handle) return 0; - ret = i2c_atr_add_adapter(priv->plat_data->atr, priv->plat_data->port, - dev, i2c_handle); + desc.chan_id = priv->plat_data->port; + desc.parent = dev; + desc.bus_handle = i2c_handle; + desc.num_aliases = 0; + + ret = i2c_atr_add_adapter(priv->plat_data->atr, &desc); fwnode_handle_put(i2c_handle); diff --git a/include/linux/i2c-atr.h b/include/linux/i2c-atr.h index 14c1f9175c0db6a8a9c6ef5d771ae68361132a76..1c3a5bcd939fc56f4a6ca1b6a5cc0ac2c17083b7 100644 --- a/include/linux/i2c-atr.h +++ b/include/linux/i2c-atr.h @@ -36,6 +36,29 @@ struct i2c_atr_ops { u16 addr); }; +/** + * struct i2c_atr_adap_desc - An ATR downstream bus descriptor + * @chan_id: Index of the new adapter (0 .. max_adapters-1). This value is + * passed to the callbacks in `struct i2c_atr_ops`. + * @parent: The device used as the parent of the new i2c adapter, or NULL + * to use the i2c-atr device as the parent. + * @bus_handle: The fwnode handle that points to the adapter's i2c + * peripherals, or NULL. + * @num_aliases: The number of aliases in this adapter's private alias pool. Set + * to zero if this adapter uses the ATR's global alias pool. + * @aliases: An optional array of private aliases used by the adapter + * instead of the ATR's global pool of aliases. Must contain + * exactly num_aliases entries if num_aliases > 0, is ignored + * otherwise. + */ +struct i2c_atr_adap_desc { + u32 chan_id; + struct device *parent; + struct fwnode_handle *bus_handle; + size_t num_aliases; + u16 *aliases; +}; + /** * i2c_atr_new() - Allocate and initialize an I2C ATR helper. * @parent: The parent (upstream) adapter @@ -65,12 +88,7 @@ void i2c_atr_delete(struct i2c_atr *atr); /** * i2c_atr_add_adapter - Create a child ("downstream") I2C bus. * @atr: The I2C ATR - * @chan_id: Index of the new adapter (0 .. max_adapters-1). This value is - * passed to the callbacks in `struct i2c_atr_ops`. - * @adapter_parent: The device used as the parent of the new i2c adapter, or NULL - * to use the i2c-atr device as the parent. - * @bus_handle: The fwnode handle that points to the adapter's i2c - * peripherals, or NULL. + * @desc: An ATR adapter descriptor * * After calling this function a new i2c bus will appear. Adding and removing * devices on the downstream bus will result in calls to the @@ -85,9 +103,7 @@ void i2c_atr_delete(struct i2c_atr *atr); * * Return: 0 on success, a negative error code otherwise. */ -int i2c_atr_add_adapter(struct i2c_atr *atr, u32 chan_id, - struct device *adapter_parent, - struct fwnode_handle *bus_handle); +int i2c_atr_add_adapter(struct i2c_atr *atr, struct i2c_atr_adap_desc *desc); /** * i2c_atr_del_adapter - Remove a child ("downstream") I2C bus added by From patchwork Wed Jan 8 16:14:09 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Romain Gantois X-Patchwork-Id: 855784 Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net [217.70.183.195]) (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 94A241FECAD; Wed, 8 Jan 2025 16:14:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.195 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736352864; cv=none; b=MHdDIcXqMgNtCsER5M8iU1UdFDuZ1YwZeC7KGvaRztbIlCH7L9c4TcW5ssR4tv+xjuIEgKlVYYV9ztb40WL1xRfr4UVD1oIKJxzNMoxq06kRxU/PyZgLq/hsbFaWZhnQCWQuvSBZftF5Ppa02ufYkX5/+SyTPqsirMJEe43UbXw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736352864; c=relaxed/simple; bh=ElrcMFfre801ulyxFMqLkRPaLESOuqyi2zuvI2fRIng=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=l+nwQpOTADCotu7trlGaYpsYopUH+u7tNEOIbe4uz/YQ6qEDb49d9ko/hLnDU/YZqT47m012QkjokihCJ/05UiZSndJfdKHyGgd0IrsRUFsbO4t+Za/3mbmp55jpCOM1w1ggy2S00DhOsPwDbGRj4sUEYvo+xx8wcKtBc/Cai2k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=F+gAUpKm; arc=none smtp.client-ip=217.70.183.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="F+gAUpKm" Received: by mail.gandi.net (Postfix) with ESMTPSA id E275E60019; Wed, 8 Jan 2025 16:14:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1736352859; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=S3FBbASfsm6RWNF+PHfRtgJcSEHsYG+JxEl5hYsdHiM=; b=F+gAUpKmXKrpn1F/hXjS/uhjdYExzZLYYxguXefS14aqxtJkVVmMZe9AhJEYl06yYq+S1k M2Ub/bQGV8ip/NieEoL1qA/PPq6ZrcmkESBUy6jVflGa34PVlQD4mjwc88CWn2KK3FowZP 3Tg1auJQLpQAQBCeIg1fWtWeGzqdjbPEIb8sO27L8/+GWaqvFEKKMy5c3v9yWROHgzD3/W SmrZgoEbi8+KpKZ0NOjXtaZXKBMQvtXEkHetvpz+Fv317x0ii9NpDq6qHtYSKCPhSIOzHB 9z5HqoqRrhF092zOPusyIsc2i3fgpSeY4mt9LZkLCe5lxuKvA8PRcgNTh9i5ZQ== From: Romain Gantois Date: Wed, 08 Jan 2025 17:14:09 +0100 Subject: [PATCH v5 8/9] i2c: Support dynamic address translation Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250108-fpc202-v5-8-a439ab999d5a@bootlin.com> References: <20250108-fpc202-v5-0-a439ab999d5a@bootlin.com> In-Reply-To: <20250108-fpc202-v5-0-a439ab999d5a@bootlin.com> To: Wolfram Sang , Tomi Valkeinen , Luca Ceresoli , Andi Shyti , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Derek Kiernan , Dragan Cvetic , Arnd Bergmann , Greg Kroah-Hartman , Mauro Carvalho Chehab , Linus Walleij , Bartosz Golaszewski Cc: Thomas Petazzoni , Kory Maincent , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-media@vger.kernel.org, linux-gpio@vger.kernel.org, Romain Gantois X-Mailer: b4 0.14.2 X-GND-Sasl: romain.gantois@bootlin.com The i2c-atr module keeps a list of associations between I2C client aliases and I2C addresses. This represents the address translation table which is programmed into an ATR channel at any given time. This list is only updated when a new client is bound to the channel. However in some cases, an ATR channel can have more downstream clients than available aliases. One example of this is an SFP module that is bound to an FPC202 port. The FPC202 port can only access up to two logical I2C addresses. However, the SFP module may expose up to three logical I2C addresses: its EEPROM on 7-bit addresses 0x50 and 0x51, and a PHY transceiver on address 0x56. In cases like these, it is necessary to reconfigure the channel's translation table on the fly, so that all three I2C addresses can be accessed when needed. As there are currently no known ATR's which do not support dynamic address translation, this feature can be enabled by default without breaking existing use cases. Modify the i2c-atr module to provide on-the-fly address translation. This is achieved by modifying an ATR channel's translation table whenever an I2C transaction with unmapped clients is requested. Add a mutex to protect alias_list. This prevents i2c_atr_dynamic_attach/detach_addr from racing with the bus notifier handler to modify alias_list. Signed-off-by: Romain Gantois --- drivers/i2c/i2c-atr.c | 249 +++++++++++++++++++++++++++++++++++++------------- 1 file changed, 188 insertions(+), 61 deletions(-) diff --git a/drivers/i2c/i2c-atr.c b/drivers/i2c/i2c-atr.c index 6c0cf46a90da61b8a418b71e852ead5f1afa1d36..0333b727c880f81f7af3a9e567f4c86221bf204d 100644 --- a/drivers/i2c/i2c-atr.c +++ b/drivers/i2c/i2c-atr.c @@ -16,6 +16,7 @@ #include #include #include +#include #define ATR_MAX_ADAPTERS 100 /* Just a sanity limit */ #define ATR_MAX_SYMLINK_LEN 11 /* Longest name is 10 chars: "channel-99" */ @@ -27,9 +28,17 @@ * @alias: I2C alias address assigned by the driver. * This is the address that will be used to issue I2C transactions * on the parent (physical) bus. + * @fixed: Alias pair cannot be replaced during dynamic address attachment. + * This flag is necessary for situations where a single I2C transaction + * contains more distinct target addresses than the ATR channel can handle. + * It marks addresses that have already been attached to an alias so + * that their alias pair is not evicted by a subsequent address in the same + * transaction. + * */ struct i2c_atr_alias_pair { struct list_head node; + bool fixed; u16 addr; u16 alias; }; @@ -58,6 +67,7 @@ struct i2c_atr_alias_pool { * @adap: The &struct i2c_adapter for the channel * @atr: The parent I2C ATR * @chan_id: The ID of this channel + * @alias_pairs_lock: Mutex protecting @alias_pairs * @alias_pairs: List of @struct i2c_atr_alias_pair containing the * assigned aliases * @alias_pool: Pool of available client aliases @@ -71,6 +81,8 @@ struct i2c_atr_chan { struct i2c_atr *atr; u32 chan_id; + /* Lock alias_pairs during attach/detach */ + struct mutex alias_pairs_lock; struct list_head alias_pairs; struct i2c_atr_alias_pool *alias_pool; @@ -155,16 +167,132 @@ static void i2c_atr_free_alias_pool(struct i2c_atr_alias_pool *alias_pool) kfree(alias_pool); } +/* Must be called with alias_pairs_lock held */ +static struct i2c_atr_alias_pair *i2c_atr_create_c2a(struct i2c_atr_chan *chan, + u16 alias, u16 addr) +{ + struct i2c_atr_alias_pair *c2a; + + lockdep_assert_held(&chan->alias_pairs_lock); + + c2a = kzalloc(sizeof(*c2a), GFP_KERNEL); + if (!c2a) + return NULL; + + c2a->addr = addr; + c2a->alias = alias; + + list_add(&c2a->node, &chan->alias_pairs); + + return c2a; +} + +/* Must be called with alias_pairs_lock held */ +static void i2c_atr_destroy_c2a(struct i2c_atr_alias_pair **pc2a) +{ + list_del(&(*pc2a)->node); + kfree(*pc2a); + *pc2a = NULL; +} + +static int i2c_atr_reserve_alias(struct i2c_atr_alias_pool *alias_pool) +{ + unsigned long idx; + u16 alias; + + spin_lock(&alias_pool->lock); + + idx = find_first_zero_bit(alias_pool->use_mask, alias_pool->size); + if (idx >= alias_pool->size) { + spin_unlock(&alias_pool->lock); + return -EBUSY; + } + + set_bit(idx, alias_pool->use_mask); + + alias = alias_pool->aliases[idx]; + + spin_unlock(&alias_pool->lock); + return alias; +} + +static void i2c_atr_release_alias(struct i2c_atr_alias_pool *alias_pool, u16 alias) +{ + unsigned int idx; + + spin_lock(&alias_pool->lock); + + for (idx = 0; idx < alias_pool->size; ++idx) { + if (alias_pool->aliases[idx] == alias) { + clear_bit(idx, alias_pool->use_mask); + spin_unlock(&alias_pool->lock); + return; + } + } + + spin_unlock(&alias_pool->lock); +} + +/* Must be called with alias_pairs_lock held */ static struct i2c_atr_alias_pair * -i2c_atr_find_mapping_by_addr(const struct list_head *list, u16 phys_addr) +i2c_atr_find_mapping_by_addr(struct i2c_atr_chan *chan, u16 addr) { + struct i2c_atr *atr = chan->atr; struct i2c_atr_alias_pair *c2a; + struct list_head *alias_pairs; + u16 alias; + int ret; + + lockdep_assert_held(&chan->alias_pairs_lock); - list_for_each_entry(c2a, list, node) { - if (c2a->addr == phys_addr) + alias_pairs = &chan->alias_pairs; + + list_for_each_entry(c2a, alias_pairs, node) { + if (c2a->addr == addr) return c2a; } + ret = i2c_atr_reserve_alias(chan->alias_pool); + if (ret < 0) { + // If no free aliases are left, replace an existing one + if (unlikely(list_empty(alias_pairs))) + return NULL; + + list_for_each_entry_reverse(c2a, alias_pairs, node) + if (!c2a->fixed) + break; + + if (c2a->fixed) + return NULL; + + atr->ops->detach_addr(atr, chan->chan_id, c2a->addr); + c2a->addr = addr; + + // Move updated entry to beginning of list + list_move(&c2a->node, alias_pairs); + + alias = c2a->alias; + } else { + alias = ret; + + c2a = i2c_atr_create_c2a(chan, alias, addr); + if (!c2a) + goto err_release_alias; + } + + ret = atr->ops->attach_addr(atr, chan->chan_id, c2a->addr, c2a->alias); + if (ret) { + dev_err(atr->dev, "failed to attach 0x%02x on channel %d: err %d\n", + addr, chan->chan_id, ret); + goto err_del_c2a; + } + + return c2a; + +err_del_c2a: + i2c_atr_destroy_c2a(&c2a); +err_release_alias: + i2c_atr_release_alias(chan->alias_pool, alias); return NULL; } @@ -180,7 +308,7 @@ static int i2c_atr_map_msgs(struct i2c_atr_chan *chan, struct i2c_msg *msgs, { struct i2c_atr *atr = chan->atr; static struct i2c_atr_alias_pair *c2a; - int i; + int i, ret = 0; /* Ensure we have enough room to save the original addresses */ if (unlikely(chan->orig_addrs_size < num)) { @@ -196,11 +324,13 @@ static int i2c_atr_map_msgs(struct i2c_atr_chan *chan, struct i2c_msg *msgs, chan->orig_addrs_size = num; } + mutex_lock(&chan->alias_pairs_lock); + for (i = 0; i < num; i++) { chan->orig_addrs[i] = msgs[i].addr; - c2a = i2c_atr_find_mapping_by_addr(&chan->alias_pairs, - msgs[i].addr); + c2a = i2c_atr_find_mapping_by_addr(chan, msgs[i].addr); + if (!c2a) { dev_err(atr->dev, "client 0x%02x not mapped!\n", msgs[i].addr); @@ -208,13 +338,19 @@ static int i2c_atr_map_msgs(struct i2c_atr_chan *chan, struct i2c_msg *msgs, while (i--) msgs[i].addr = chan->orig_addrs[i]; - return -ENXIO; + ret = -ENXIO; + goto out_unlock; } + // Prevent c2a from being overwritten by another client in this transaction + c2a->fixed = true; + msgs[i].addr = c2a->alias; } - return 0; +out_unlock: + mutex_unlock(&chan->alias_pairs_lock); + return ret; } /* @@ -227,10 +363,24 @@ static int i2c_atr_map_msgs(struct i2c_atr_chan *chan, struct i2c_msg *msgs, static void i2c_atr_unmap_msgs(struct i2c_atr_chan *chan, struct i2c_msg *msgs, int num) { + struct i2c_atr_alias_pair *c2a; int i; for (i = 0; i < num; i++) msgs[i].addr = chan->orig_addrs[i]; + + mutex_lock(&chan->alias_pairs_lock); + + if (unlikely(list_empty(&chan->alias_pairs))) + goto out_unlock; + + // unfix c2a entries so that subsequent transfers can reuse their aliases + list_for_each_entry(c2a, &chan->alias_pairs, node) { + c2a->fixed = false; + } + +out_unlock: + mutex_unlock(&chan->alias_pairs_lock); } static int i2c_atr_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, @@ -268,14 +418,23 @@ static int i2c_atr_smbus_xfer(struct i2c_adapter *adap, u16 addr, struct i2c_atr *atr = chan->atr; struct i2c_adapter *parent = atr->parent; struct i2c_atr_alias_pair *c2a; + u16 alias; + + mutex_lock(&chan->alias_pairs_lock); + + c2a = i2c_atr_find_mapping_by_addr(chan, addr); - c2a = i2c_atr_find_mapping_by_addr(&chan->alias_pairs, addr); if (!c2a) { dev_err(atr->dev, "client 0x%02x not mapped!\n", addr); + mutex_unlock(&chan->alias_pairs_lock); return -ENXIO; } - return i2c_smbus_xfer(parent, c2a->alias, flags, read_write, command, + alias = c2a->alias; + + mutex_unlock(&chan->alias_pairs_lock); + + return i2c_smbus_xfer(parent, alias, flags, read_write, command, size, data); } @@ -317,44 +476,6 @@ static const struct i2c_lock_operations i2c_atr_lock_ops = { .unlock_bus = i2c_atr_unlock_bus, }; -static int i2c_atr_reserve_alias(struct i2c_atr_alias_pool *alias_pool) -{ - unsigned long idx; - u16 alias; - - spin_lock(&alias_pool->lock); - - idx = find_first_zero_bit(alias_pool->use_mask, alias_pool->size); - if (idx >= alias_pool->size) { - spin_unlock(&alias_pool->lock); - return -EBUSY; - } - - set_bit(idx, alias_pool->use_mask); - - alias = alias_pool->aliases[idx]; - - spin_unlock(&alias_pool->lock); - return alias; -} - -static void i2c_atr_release_alias(struct i2c_atr_alias_pool *alias_pool, u16 alias) -{ - unsigned int idx; - - spin_lock(&alias_pool->lock); - - for (idx = 0; idx < alias_pool->size; ++idx) { - if (alias_pool->aliases[idx] == alias) { - clear_bit(idx, alias_pool->use_mask); - spin_unlock(&alias_pool->lock); - return; - } - } - - spin_unlock(&alias_pool->lock); -} - static int i2c_atr_attach_addr(struct i2c_adapter *adapter, u16 addr) { @@ -372,7 +493,9 @@ static int i2c_atr_attach_addr(struct i2c_adapter *adapter, alias = ret; - c2a = kzalloc(sizeof(*c2a), GFP_KERNEL); + mutex_lock(&chan->alias_pairs_lock); + + c2a = i2c_atr_create_c2a(chan, alias, addr); if (!c2a) { ret = -ENOMEM; goto err_release_alias; @@ -380,22 +503,19 @@ static int i2c_atr_attach_addr(struct i2c_adapter *adapter, ret = atr->ops->attach_addr(atr, chan->chan_id, addr, alias); if (ret) - goto err_free; + goto err_del_c2a; dev_dbg(atr->dev, "chan%u: using alias 0x%02x for addr 0x%02x\n", chan->chan_id, alias, addr); - c2a->addr = addr; - c2a->alias = alias; - list_add(&c2a->node, &chan->alias_pairs); - - return 0; + goto out_unlock; -err_free: - kfree(c2a); +err_del_c2a: + i2c_atr_destroy_c2a(&c2a); err_release_alias: i2c_atr_release_alias(chan->alias_pool, alias); - +out_unlock: + mutex_unlock(&chan->alias_pairs_lock); return ret; } @@ -408,21 +528,25 @@ static void i2c_atr_detach_addr(struct i2c_adapter *adapter, atr->ops->detach_addr(atr, chan->chan_id, addr); - c2a = i2c_atr_find_mapping_by_addr(&chan->alias_pairs, addr); + mutex_lock(&chan->alias_pairs_lock); + + c2a = i2c_atr_find_mapping_by_addr(chan, addr); if (!c2a) { /* This should never happen */ dev_warn(atr->dev, "Unable to find address mapping\n"); + mutex_unlock(&chan->alias_pairs_lock); return; } + mutex_unlock(&chan->alias_pairs_lock); + i2c_atr_release_alias(chan->alias_pool, c2a->alias); dev_dbg(atr->dev, "chan%u: detached alias 0x%02x from addr 0x%02x\n", chan->chan_id, c2a->alias, addr); - list_del(&c2a->node); - kfree(c2a); + i2c_atr_destroy_c2a(&c2a); } static int i2c_atr_bus_notifier_call(struct notifier_block *nb, @@ -633,6 +757,7 @@ int i2c_atr_add_adapter(struct i2c_atr *atr, struct i2c_atr_adap_desc *desc) chan->atr = atr; chan->chan_id = chan_id; INIT_LIST_HEAD(&chan->alias_pairs); + mutex_init(&chan->alias_pairs_lock); mutex_init(&chan->orig_addrs_lock); snprintf(chan->adap.name, sizeof(chan->adap.name), "i2c-%d-atr-%d", @@ -709,6 +834,7 @@ int i2c_atr_add_adapter(struct i2c_atr *atr, struct i2c_atr_adap_desc *desc) err_fwnode_put: fwnode_handle_put(dev_fwnode(&chan->adap.dev)); mutex_destroy(&chan->orig_addrs_lock); + mutex_destroy(&chan->alias_pairs_lock); kfree(chan); return ret; } @@ -745,6 +871,7 @@ void i2c_atr_del_adapter(struct i2c_atr *atr, u32 chan_id) fwnode_handle_put(fwnode); mutex_destroy(&chan->orig_addrs_lock); + mutex_destroy(&chan->alias_pairs_lock); kfree(chan->orig_addrs); kfree(chan); } From patchwork Wed Jan 8 16:14:10 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Romain Gantois X-Patchwork-Id: 855783 Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net [217.70.183.195]) (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 A14BF1FF1D9; Wed, 8 Jan 2025 16:14:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.195 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736352865; cv=none; b=ArQWSSdzAZ645W/rusDPK2spIna3eiqX69poUoF93uq74XW5rGkYJtP9cgLvEDfbR13WpNQKcdr/hoATqDZg6AT8Qi2T2DJxFIe/ux0ssw2dSrk+PZJXpx/GtZMv8Afsa0DURI1jo/v4LxR0BSbF2BlfJPdfXOMCfwRgJei45VA= ARC-Message-Signature: i=1; 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Wed, 8 Jan 2025 16:14:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1736352860; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=AeFWjpwRRSFYTDdyfQNzPckQyxB6BcLqkMuH3YbTxvQ=; b=AQQPVv15j/ZGyM8rnMRIHa3WW+jI6hewlz7jyDWmVeXJQwr+vJ5vCyEvrtORviRS3uxLiu CRxd+qxUVwm3VnBpWpZRs3I4CEYTOYMUpgMpU2nGlsxBrSJ/3tx1mHMynyJsuatgMYqMRX 5+czA6863kyItJHy7iDblk4Vb19kxG9nR6VeNftOQrufyofPl6sVbA96vhkoEiORfBgdsW NVILDSd2wqJXn71hw26NC66udmqRg0QJFvOdSDdJHeYCj6ivn5h9EuIpQ2DPCzh/fLpErq 927P+/ttxjfIneSZvqJ3mwNsUyMhmXnDIkMmTMtr6hIo17YH4Gy0Yt0DTTib4g== From: Romain Gantois Date: Wed, 08 Jan 2025 17:14:10 +0100 Subject: [PATCH v5 9/9] misc: add FPC202 dual port controller driver Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250108-fpc202-v5-9-a439ab999d5a@bootlin.com> References: <20250108-fpc202-v5-0-a439ab999d5a@bootlin.com> In-Reply-To: <20250108-fpc202-v5-0-a439ab999d5a@bootlin.com> To: Wolfram Sang , Tomi Valkeinen , Luca Ceresoli , Andi Shyti , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Derek Kiernan , Dragan Cvetic , Arnd Bergmann , Greg Kroah-Hartman , Mauro Carvalho Chehab , Linus Walleij , Bartosz Golaszewski Cc: Thomas Petazzoni , Kory Maincent , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-media@vger.kernel.org, linux-gpio@vger.kernel.org, Romain Gantois X-Mailer: b4 0.14.2 X-GND-Sasl: romain.gantois@bootlin.com The TI FPC202 dual port controller serves as a low-speed signal aggregator for common port types such as SFP, QSFP, Mini-SAS HD, and others. It aggregates GPIO and I2C signals across two downstream ports, acting as both a GPIO controller and an I2C address translator for up to two logical devices per port. Signed-off-by: Romain Gantois --- MAINTAINERS | 1 + drivers/misc/Kconfig | 11 ++ drivers/misc/Makefile | 1 + drivers/misc/ti_fpc202.c | 440 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 453 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 2ef5c0d395b3668167dddbd27237a2177f85571e..865ef413b38c293e1c7b1405322fafe9df81ea96 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -23502,6 +23502,7 @@ M: Romain Gantois L: linux-kernel@vger.kernel.org S: Maintained F: Documentation/devicetree/bindings/misc/ti,fpc202.yaml +F: drivers/misc/ti_fpc202.c TI FPD-LINK DRIVERS M: Tomi Valkeinen diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index 09cbe3f0ab1e56f85852c0cb50cfc03cae659d2b..3c7e82e86e4ae83eff84999d123cd8c0f018323c 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -114,6 +114,17 @@ config RPMB If unsure, select N. +config TI_FPC202 + tristate "TI FPC202 Dual Port Controller" + select GPIOLIB + depends on I2C_ATR + help + If you say yes here you get support for the Texas Instruments FPC202 + Dual Port Controller. + + This driver can also be built as a module. If so, the module will be + called fpc202. + config TIFM_CORE tristate "TI Flash Media interface support" depends on PCI diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index 40bf953185c773afa91f7784a286ae0752bb0b53..ba47db46a5ff2559de597447ce7e2d88e26efa61 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -12,6 +12,7 @@ obj-$(CONFIG_ATMEL_SSC) += atmel-ssc.o obj-$(CONFIG_DUMMY_IRQ) += dummy-irq.o obj-$(CONFIG_ICS932S401) += ics932s401.o obj-$(CONFIG_LKDTM) += lkdtm/ +obj-$(CONFIG_TI_FPC202) += ti_fpc202.o obj-$(CONFIG_TIFM_CORE) += tifm_core.o obj-$(CONFIG_TIFM_7XX1) += tifm_7xx1.o obj-$(CONFIG_PHANTOM) += phantom.o diff --git a/drivers/misc/ti_fpc202.c b/drivers/misc/ti_fpc202.c new file mode 100644 index 0000000000000000000000000000000000000000..e251d8e0a640f05d59e5b20665d8a8237b8c2724 --- /dev/null +++ b/drivers/misc/ti_fpc202.c @@ -0,0 +1,440 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ti_fpc202.c - FPC202 Dual Port Controller driver + * + * Copyright (C) 2024 Bootlin + * + */ + +#include +#include +#include +#include +#include +#include +#include + +#define FPC202_NUM_PORTS 2 +#define FPC202_ALIASES_PER_PORT 2 + +/* + * GPIO: port mapping + * + * 0: P0_S0_IN_A + * 1: P0_S1_IN_A + * 2: P1_S0_IN_A + * 3: P1_S1_IN_A + * 4: P0_S0_IN_B + * ... + * 8: P0_S0_IN_C + * ... + * 12: P0_S0_OUT_A + * ... + * 16: P0_S0_OUT_B + * ... + * 19: P1_S1_OUT_B + * + */ + +#define FPC202_GPIO_COUNT 20 +#define FPC202_GPIO_P0_S0_IN_B 4 +#define FPC202_GPIO_P0_S0_OUT_A 12 + +#define FPC202_REG_IN_A_INT 0x6 +#define FPC202_REG_IN_C_IN_B 0x7 +#define FPC202_REG_OUT_A_OUT_B 0x8 + +#define FPC202_REG_OUT_A_OUT_B_VAL 0xa + +#define FPC202_REG_MOD_DEV(port, dev) (0xb4 + ((port) * 4) + (dev)) +#define FPC202_REG_AUX_DEV(port, dev) (0xb6 + ((port) * 4) + (dev)) + +/* + * The FPC202 doesn't support turning off address translation on a single port. + * So just set an invalid I2C address as the translation target when no client + * address is attached. + */ +#define FPC202_REG_DEV_INVALID 0 + +/* Even aliases are assigned to device 0 and odd aliases to device 1 */ +#define fpc202_dev_num_from_alias(alias) ((alias) % 2) + +struct fpc202_priv { + struct i2c_client *client; + struct i2c_atr *atr; + struct gpio_desc *en_gpio; + struct gpio_chip gpio; + + /* Lock REG_MOD/AUX_DEV and addr_caches during attach/detach */ + struct mutex reg_dev_lock; + + /* Cached device addresses for both ports and their devices */ + u8 addr_caches[2][2]; + + /* Keep track of which ports were probed */ + DECLARE_BITMAP(probed_ports, FPC202_NUM_PORTS); +}; + +static void fpc202_fill_alias_table(struct i2c_client *client, u16 *aliases, int port_id) +{ + u16 first_alias; + int i; + + /* + * There is a predefined list of aliases for each FPC202 I2C + * self-address. This allows daisy-chained FPC202 units to + * automatically take on different sets of aliases. + * Each port of an FPC202 unit is assigned two aliases from this list. + */ + first_alias = 0x10 + 4 * port_id + 8 * ((u16)client->addr - 2); + + for (i = 0; i < FPC202_ALIASES_PER_PORT; i++) + aliases[i] = first_alias + i; +} + +static int fpc202_gpio_get_dir(int offset) +{ + return offset < FPC202_GPIO_P0_S0_OUT_A ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT; +} + +static int fpc202_read(struct fpc202_priv *priv, u8 reg) +{ + int val; + + val = i2c_smbus_read_byte_data(priv->client, reg); + return val; +} + +static int fpc202_write(struct fpc202_priv *priv, u8 reg, u8 value) +{ + return i2c_smbus_write_byte_data(priv->client, reg, value); +} + +static void fpc202_set_enable(struct fpc202_priv *priv, int enable) +{ + if (!priv->en_gpio) + return; + + gpiod_set_value(priv->en_gpio, enable); +} + +static void fpc202_gpio_set(struct gpio_chip *chip, unsigned int offset, + int value) +{ + struct fpc202_priv *priv = gpiochip_get_data(chip); + int ret; + u8 val; + + if (fpc202_gpio_get_dir(offset) == GPIO_LINE_DIRECTION_IN) + return; + + ret = fpc202_read(priv, FPC202_REG_OUT_A_OUT_B_VAL); + if (ret < 0) { + dev_err(&priv->client->dev, "Failed to set GPIO %d value! err %d\n", offset, ret); + return; + } + + val = (u8)ret; + + if (value) + val |= BIT(offset - FPC202_GPIO_P0_S0_OUT_A); + else + val &= ~BIT(offset - FPC202_GPIO_P0_S0_OUT_A); + + fpc202_write(priv, FPC202_REG_OUT_A_OUT_B_VAL, val); +} + +static int fpc202_gpio_get(struct gpio_chip *chip, unsigned int offset) +{ + struct fpc202_priv *priv = gpiochip_get_data(chip); + u8 reg, bit; + int ret; + + if (offset < FPC202_GPIO_P0_S0_IN_B) { + reg = FPC202_REG_IN_A_INT; + bit = BIT(4 + offset); + } else if (offset < FPC202_GPIO_P0_S0_OUT_A) { + reg = FPC202_REG_IN_C_IN_B; + bit = BIT(offset - FPC202_GPIO_P0_S0_IN_B); + } else { + reg = FPC202_REG_OUT_A_OUT_B_VAL; + bit = BIT(offset - FPC202_GPIO_P0_S0_OUT_A); + } + + ret = fpc202_read(priv, reg); + if (ret < 0) + return ret; + + return !!(((u8)ret) & bit); +} + +static int fpc202_gpio_direction_input(struct gpio_chip *chip, unsigned int offset) +{ + if (fpc202_gpio_get_dir(offset) == GPIO_LINE_DIRECTION_OUT) + return -EINVAL; + + return 0; +} + +static int fpc202_gpio_direction_output(struct gpio_chip *chip, unsigned int offset, + int value) +{ + struct fpc202_priv *priv = gpiochip_get_data(chip); + int ret; + u8 val; + + if (fpc202_gpio_get_dir(offset) == GPIO_LINE_DIRECTION_IN) + return -EINVAL; + + fpc202_gpio_set(chip, offset, value); + + ret = fpc202_read(priv, FPC202_REG_OUT_A_OUT_B); + if (ret < 0) + return ret; + + val = (u8)ret | BIT(offset - FPC202_GPIO_P0_S0_OUT_A); + + return fpc202_write(priv, FPC202_REG_OUT_A_OUT_B, val); +} + +/* + * Set the translation table entry associated with a port and device number. + * + * Each downstream port of the FPC202 has two fixed aliases corresponding to + * device numbers 0 and 1. If one of these aliases is found in an incoming I2C + * transfer, it will be translated to the address given by the corresponding + * translation table entry. + */ +static int fpc202_write_dev_addr(struct fpc202_priv *priv, u32 port_id, int dev_num, u16 addr) +{ + int ret, reg_mod, reg_aux; + u8 val; + + guard(mutex)(&priv->reg_dev_lock); + + reg_mod = FPC202_REG_MOD_DEV(port_id, dev_num); + reg_aux = FPC202_REG_AUX_DEV(port_id, dev_num); + val = addr & 0x7f; + + ret = fpc202_write(priv, reg_mod, val); + if (ret) + return ret; + + /* + * The FPC202 datasheet is unclear about the role of the AUX registers. + * Empirically, writing to them as well seems to be necessary for + * address translation to function properly. + */ + ret = fpc202_write(priv, reg_aux, val); + + priv->addr_caches[port_id][dev_num] = val; + + return ret; +} + +static int fpc202_attach_addr(struct i2c_atr *atr, u32 chan_id, + u16 addr, u16 alias) +{ + struct fpc202_priv *priv = i2c_atr_get_driver_data(atr); + + dev_dbg(&priv->client->dev, "attaching address 0x%02x to alias 0x%02x\n", addr, alias); + + return fpc202_write_dev_addr(priv, chan_id, fpc202_dev_num_from_alias(alias), addr); +} + +static void fpc202_detach_addr(struct i2c_atr *atr, u32 chan_id, + u16 addr) +{ + struct fpc202_priv *priv = i2c_atr_get_driver_data(atr); + int dev_num, reg_mod, val; + + for (dev_num = 0; dev_num < 2; dev_num++) { + reg_mod = FPC202_REG_MOD_DEV(chan_id, dev_num); + + mutex_lock(&priv->reg_dev_lock); + + val = priv->addr_caches[chan_id][dev_num]; + + mutex_unlock(&priv->reg_dev_lock); + + if (val < 0) { + dev_err(&priv->client->dev, "failed to read register 0x%x while detaching address 0x%02x\n", + reg_mod, addr); + return; + } + + if (val == (addr & 0x7f)) { + fpc202_write_dev_addr(priv, chan_id, dev_num, FPC202_REG_DEV_INVALID); + return; + } + } +} + +static const struct i2c_atr_ops fpc202_atr_ops = { + .attach_addr = fpc202_attach_addr, + .detach_addr = fpc202_detach_addr, +}; + +static int fpc202_probe_port(struct fpc202_priv *priv, struct device_node *i2c_handle, int port_id) +{ + u16 aliases[FPC202_ALIASES_PER_PORT] = { }; + struct device *dev = &priv->client->dev; + struct i2c_atr_adap_desc desc = { }; + int ret = 0; + + desc.chan_id = port_id; + desc.parent = dev; + desc.bus_handle = of_node_to_fwnode(i2c_handle); + desc.num_aliases = FPC202_ALIASES_PER_PORT; + + fpc202_fill_alias_table(priv->client, aliases, port_id); + desc.aliases = aliases; + + ret = i2c_atr_add_adapter(priv->atr, &desc); + if (ret) + return ret; + + set_bit(port_id, priv->probed_ports); + + ret = fpc202_write_dev_addr(priv, port_id, 0, FPC202_REG_DEV_INVALID); + if (ret) + return ret; + + return fpc202_write_dev_addr(priv, port_id, 1, FPC202_REG_DEV_INVALID); +} + +static void fpc202_remove_port(struct fpc202_priv *priv, int port_id) +{ + i2c_atr_del_adapter(priv->atr, port_id); + clear_bit(port_id, priv->probed_ports); +} + +static int fpc202_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + struct device_node *i2c_handle; + struct fpc202_priv *priv; + int ret, port_id; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + mutex_init(&priv->reg_dev_lock); + + priv->client = client; + i2c_set_clientdata(client, priv); + + priv->en_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_HIGH); + if (IS_ERR(priv->en_gpio)) { + ret = PTR_ERR(priv->en_gpio); + dev_err(dev, "failed to fetch enable GPIO! err %d\n", ret); + goto destroy_mutex; + } + + priv->gpio.label = "gpio-fpc202"; + priv->gpio.base = -1; + priv->gpio.direction_input = fpc202_gpio_direction_input; + priv->gpio.direction_output = fpc202_gpio_direction_output; + priv->gpio.set = fpc202_gpio_set; + priv->gpio.get = fpc202_gpio_get; + priv->gpio.ngpio = FPC202_GPIO_COUNT; + priv->gpio.parent = dev; + priv->gpio.owner = THIS_MODULE; + + ret = gpiochip_add_data(&priv->gpio, priv); + if (ret) { + priv->gpio.parent = NULL; + dev_err(dev, "failed to add gpiochip err %d\n", ret); + goto disable_gpio; + } + + priv->atr = i2c_atr_new(client->adapter, dev, &fpc202_atr_ops, 2); + if (IS_ERR(priv->atr)) { + ret = PTR_ERR(priv->atr); + dev_err(dev, "failed to create i2c atr err %d\n", ret); + goto disable_gpio; + } + + i2c_atr_set_driver_data(priv->atr, priv); + + bitmap_zero(priv->probed_ports, FPC202_NUM_PORTS); + + for_each_child_of_node(dev->of_node, i2c_handle) { + ret = of_property_read_u32(i2c_handle, "reg", &port_id); + if (ret) { + if (ret == -EINVAL) + continue; + + dev_err(dev, "failed to read 'reg' property of child node, err %d\n", ret); + goto unregister_chans; + } + + if (port_id > FPC202_NUM_PORTS) { + dev_err(dev, "port ID %d is out of range!\n", port_id); + ret = -EINVAL; + goto unregister_chans; + } + + ret = fpc202_probe_port(priv, i2c_handle, port_id); + if (ret) { + dev_err(dev, "Failed to probe port %d, err %d\n", port_id, ret); + goto unregister_chans; + } + } + + dev_info(&client->dev, "%s FPC202 Dual Port controller found\n", client->name); + + goto out; + +unregister_chans: + for_each_set_bit(port_id, priv->probed_ports, FPC202_NUM_PORTS) + fpc202_remove_port(priv, port_id); + + i2c_atr_delete(priv->atr); +disable_gpio: + fpc202_set_enable(priv, 0); + gpiochip_remove(&priv->gpio); +destroy_mutex: + mutex_destroy(&priv->reg_dev_lock); +out: + return ret; +} + +static void fpc202_remove(struct i2c_client *client) +{ + struct fpc202_priv *priv = i2c_get_clientdata(client); + int port_id; + + for_each_set_bit(port_id, priv->probed_ports, FPC202_NUM_PORTS) + fpc202_remove_port(priv, port_id); + + mutex_destroy(&priv->reg_dev_lock); + + i2c_atr_delete(priv->atr); + + fpc202_set_enable(priv, 0); + gpiochip_remove(&priv->gpio); +} + +static const struct of_device_id fpc202_of_match[] = { + { .compatible = "ti,fpc202" }, + {} +}; +MODULE_DEVICE_TABLE(of, fpc202_of_match); + +static struct i2c_driver fpc202_driver = { + .driver = { + .name = "fpc202", + .of_match_table = fpc202_of_match, + }, + .probe = fpc202_probe, + .remove = fpc202_remove, +}; + +module_i2c_driver(fpc202_driver); + +MODULE_AUTHOR("Romain Gantois "); +MODULE_DESCRIPTION("TI FPC202 Dual Port Controller driver"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(I2C_ATR);