From patchwork Wed Jan 15 09:25:40 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Romain Gantois X-Patchwork-Id: 857796 Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [217.70.183.199]) (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 B755124819C; Wed, 15 Jan 2025 09:26:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.199 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736933171; cv=none; b=l5pu+FMG4CnTRpdlI/czqQjA4AWJ2R/+pI/Gb+2GVrnFQMZbiXJt8sOK0SV3wLU/OW3vTCK0Y/GxoDNsowiLMUKYWCp0mS4Ig4S1qVk32/HMiTkUQ4Ld62WiWsydXvY3X2oKncknp7TuSHtKreT/LnRJL6b/lAgOWXvTnGkvy2Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736933171; c=relaxed/simple; bh=ASQ6Fw5qjJ/O0iPC+m3DVBcrmxyvL2adNzVtUrBPFi0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=WZj3V0HQyiuODyMeZsCF/yEcIQpxM8BVcIfvzJyBaYp1KSS9cuHIEpwf5kbuU2+Iw31I4TYKtpC+1u0fyqySQxyzScEUx6bJIHyHuVlsWDMufiuX4O3eOxVrzacEXdAQXZXLdHZGBKCj00aixKVeGDR1ZtGAbd8fWynnc3hx8l0= 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=AIBLcUZP; arc=none smtp.client-ip=217.70.183.199 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="AIBLcUZP" Received: by mail.gandi.net (Postfix) with ESMTPSA id 367B1FF80E; Wed, 15 Jan 2025 09:26:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1736933167; 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=MOSmciKpV7p8jAIDgx8nyxSnPVuTNrLy1iE6XeNvccY=; b=AIBLcUZPJSPEnUMDAI9qnDicfpwFRAV6b1gctWIOmhwFrcKvxsUjRl7MS3ILBYszv4vNjO xFM5ZgBFf3sU1e7UZeNKf8FmupgAZQUtcudzUetUE/upmu8SMPWSrcUrqV9//GcaTnmNVF YVT+NSmSsTHnOl6Dum2toC3uUw0V3h2feyLefyGmZM3z3vggIeHENUX8BgYqNwzqZraVLd bcw+EGoWStIpcOJ5/EfllVwLy6It23ABjK2CyeYNhLlE1Kk+8fpPTZ8Fqb3kRcCa6PC9v5 m4xVh8HAyQApuZRkJrFXgIpW+HLg0SBkvp9GJptINBQjy7lwl6LwJck4AExRiA== From: Romain Gantois Date: Wed, 15 Jan 2025 10:25:40 +0100 Subject: [PATCH v6 3/9] media: i2c: ds90ub960: Protect alias_use_mask with a mutex Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250115-fpc202-v6-3-d47a34820753@bootlin.com> References: <20250115-fpc202-v6-0-d47a34820753@bootlin.com> In-Reply-To: <20250115-fpc202-v6-0-d47a34820753@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 aliased_addrs list represents the occupation of an RX port's hardware alias table. This list and the underlying hardware table are only accessed in the attach/detach_client() callbacks. These functions are only called from a bus notifier handler in i2c-atr.c, which is always called with the notifier chain's semaphore held. This indirectly prevents concurrent access to the aliased_addrs list. However, more explicit and direct locking is preferable. Moreover, with the introduction of dynamic address translation in a future patch, the attach/detach_client() callbacks will be called from outside of the notifier chain's read section. Introduce a mutex to protect access to the aliased_addrs list and its underlying hardware table. Signed-off-by: Romain Gantois --- drivers/media/i2c/ds90ub960.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/media/i2c/ds90ub960.c b/drivers/media/i2c/ds90ub960.c index 13fb6020364d2b2d774400755f65da19365f220b..0c83c07c287c5eb168ec5d761f3d803c96d1e649 100644 --- a/drivers/media/i2c/ds90ub960.c +++ b/drivers/media/i2c/ds90ub960.c @@ -27,6 +27,7 @@ */ #include +#include #include #include #include @@ -467,6 +468,8 @@ struct ub960_rxport { }; } eq; + /* lock for aliased_addrs and associated registers */ + struct mutex aliased_addrs_lock; u16 aliased_addrs[UB960_MAX_PORT_ALIASES]; }; @@ -1031,6 +1034,8 @@ static int ub960_atr_attach_client(struct i2c_atr *atr, u32 chan_id, struct device *dev = &priv->client->dev; unsigned int reg_idx; + guard(mutex)(&rxport->aliased_addrs_lock); + for (reg_idx = 0; reg_idx < ARRAY_SIZE(rxport->aliased_addrs); reg_idx++) { if (!rxport->aliased_addrs[reg_idx]) break; @@ -1062,6 +1067,8 @@ static void ub960_atr_detach_client(struct i2c_atr *atr, u32 chan_id, struct device *dev = &priv->client->dev; unsigned int reg_idx; + guard(mutex)(&rxport->aliased_addrs_lock); + for (reg_idx = 0; reg_idx < ARRAY_SIZE(rxport->aliased_addrs); reg_idx++) { if (rxport->aliased_addrs[reg_idx] == client->addr) break; @@ -3181,6 +3188,8 @@ static void ub960_rxport_free_ports(struct ub960_data *priv) fwnode_handle_put(rxport->source.ep_fwnode); fwnode_handle_put(rxport->ser.fwnode); + mutex_destroy(&rxport->aliased_addrs_lock); + kfree(rxport); priv->rxports[nport] = NULL; } @@ -3401,6 +3410,8 @@ static int ub960_parse_dt_rxport(struct ub960_data *priv, unsigned int nport, if (ret) goto err_put_remote_fwnode; + mutex_init(&rxport->aliased_addrs_lock); + return 0; err_put_remote_fwnode: From patchwork Wed Jan 15 09:25:42 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Romain Gantois X-Patchwork-Id: 857795 Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [217.70.183.199]) (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 EA2A6236ED0; 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arc=none smtp.client-ip=217.70.183.199 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="a2VKsom2" Received: by mail.gandi.net (Postfix) with ESMTPSA id 67DC2FF810; Wed, 15 Jan 2025 09:26:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1736933169; 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=O5cVFCY+TsCDTrv9EgLty2YjRj1DRRk5ohtcB0F/zDg=; b=a2VKsom27GrcEh4xPjc9v4x+ORGnPqPChD9BchYCl6jliBv+shPHFU60ATnHnlaVHra6xu KAG5ufICzRr1+r8l+Vt0hLkHCoX3r7hk5EqWMGsigT4q4Q7d14/DzG8WUKNBy0bSGH+Cbw KeQu3y2oZzxnvNFfANpwJJzw899JOOGPeWOpm7rGGfkJqExwmqHCxGLw7Q8PehK2NWlgJr TmW6p3dsN5ZEujjDeHMGx078ufGNjU3aUL63ntARhonCuCLoGgqVO8DvcfUsaDFWYXqQgy FPKKoizNw4fsPo/TWyHaPxITtRSNXk1fW4rrjpB/of2zodqjemVwMgxLxp/mWQ== From: Romain Gantois Date: Wed, 15 Jan 2025 10:25:42 +0100 Subject: [PATCH v6 5/9] i2c: move ATR alias pool to a separate struct Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250115-fpc202-v6-5-d47a34820753@bootlin.com> References: <20250115-fpc202-v6-0-d47a34820753@bootlin.com> In-Reply-To: <20250115-fpc202-v6-0-d47a34820753@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 Each I2C address translator (ATR) has a pool of client aliases which can be used as translation targets. Some ATRs have a single alias pool shared by all downstream channels, while others have a separate alias pool for each channel. Currently, this alias pool is represented by the "aliases", "num_aliases", and "use_mask" fields of struct i2c_atr. In preparation for adding per-channel alias pool support, move the "aliases", "num_aliases", "use_mask" and associated lock to a new struct called "struct alias_pool". Signed-off-by: Romain Gantois --- drivers/i2c/i2c-atr.c | 172 +++++++++++++++++++++++++++++++------------------- 1 file changed, 107 insertions(+), 65 deletions(-) diff --git a/drivers/i2c/i2c-atr.c b/drivers/i2c/i2c-atr.c index f04bd4f9e3143837c035cd08d23d5dfc37f151cb..019089346ce4622e46a4802c990cdacd24d47734 100644 --- a/drivers/i2c/i2c-atr.c +++ b/drivers/i2c/i2c-atr.c @@ -34,6 +34,23 @@ struct i2c_atr_alias_pair { u16 alias; }; +/** + * struct i2c_atr_alias_pool - Pool of client aliases available for an ATR. + * @size: Total number of aliases + * + * @lock: Lock protecting @aliases and @use_mask + * @aliases: Array of aliases, must hold exactly @size elements + * @use_mask: Mask of used aliases + */ +struct i2c_atr_alias_pool { + size_t size; + + /* Protects aliases and use_mask */ + spinlock_t lock; + u16 *aliases; + unsigned long *use_mask; +}; + /** * struct i2c_atr_chan - Data for a channel. * @adap: The &struct i2c_adapter for the channel @@ -67,10 +84,7 @@ 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 - * @num_aliases: Number of aliases in the aliases array - * @aliases: The aliases array - * @alias_mask_lock: Lock protecting alias_use_mask - * @alias_use_mask: Bitmask for used aliases in aliases array + * @alias_pool: Pool of available client aliases * @i2c_nb: Notifier for remote client add & del events * @adapter: Array of adapters */ @@ -86,17 +100,54 @@ struct i2c_atr { struct mutex lock; int max_adapters; - size_t num_aliases; - const u16 *aliases; - /* Protects alias_use_mask */ - spinlock_t alias_mask_lock; - unsigned long *alias_use_mask; + struct i2c_atr_alias_pool *alias_pool; struct notifier_block i2c_nb; struct i2c_adapter *adapter[] __counted_by(max_adapters); }; +static struct i2c_atr_alias_pool *i2c_atr_alloc_alias_pool(size_t num_aliases) +{ + struct i2c_atr_alias_pool *alias_pool; + int ret; + + alias_pool = kzalloc(sizeof(*alias_pool), GFP_KERNEL); + if (!alias_pool) + return ERR_PTR(-ENOMEM); + + alias_pool->size = num_aliases; + + alias_pool->aliases = kcalloc(num_aliases, sizeof(*alias_pool->aliases), GFP_KERNEL); + if (!alias_pool->aliases) { + ret = -ENOMEM; + goto err_free_alias_pool; + } + + alias_pool->use_mask = bitmap_zalloc(num_aliases, GFP_KERNEL); + if (!alias_pool->use_mask) { + ret = -ENOMEM; + goto err_free_aliases; + } + + spin_lock_init(&alias_pool->lock); + + return alias_pool; + +err_free_aliases: + kfree(alias_pool->aliases); +err_free_alias_pool: + kfree(alias_pool); + return ERR_PTR(ret); +} + +static void i2c_atr_free_alias_pool(struct i2c_atr_alias_pool *alias_pool) +{ + bitmap_free(alias_pool->use_mask); + kfree(alias_pool->aliases); + kfree(alias_pool); +} + static struct i2c_atr_alias_pair * i2c_atr_find_mapping_by_addr(const struct list_head *list, u16 phys_addr) { @@ -259,44 +310,42 @@ 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 *atr) +static int i2c_atr_reserve_alias(struct i2c_atr_alias_pool *alias_pool) { unsigned long idx; + u16 alias; - spin_lock(&atr->alias_mask_lock); + spin_lock(&alias_pool->lock); - idx = find_first_zero_bit(atr->alias_use_mask, atr->num_aliases); - if (idx >= atr->num_aliases) { - spin_unlock(&atr->alias_mask_lock); - dev_err(atr->dev, "failed to find a free alias\n"); + 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, atr->alias_use_mask); + set_bit(idx, alias_pool->use_mask); - spin_unlock(&atr->alias_mask_lock); + alias = alias_pool->aliases[idx]; - return atr->aliases[idx]; + spin_unlock(&alias_pool->lock); + return alias; } -static void i2c_atr_release_alias(struct i2c_atr *atr, u16 alias) +static void i2c_atr_release_alias(struct i2c_atr_alias_pool *alias_pool, u16 alias) { unsigned int idx; - spin_lock(&atr->alias_mask_lock); + spin_lock(&alias_pool->lock); - for (idx = 0; idx < atr->num_aliases; ++idx) { - if (atr->aliases[idx] == alias) { - clear_bit(idx, atr->alias_use_mask); - spin_unlock(&atr->alias_mask_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(&atr->alias_mask_lock); - - /* This should never happen */ - dev_warn(atr->dev, "Unable to find mapped alias\n"); + spin_unlock(&alias_pool->lock); } static int i2c_atr_attach_addr(struct i2c_adapter *adapter, @@ -308,9 +357,11 @@ static int i2c_atr_attach_addr(struct i2c_adapter *adapter, u16 alias; int ret; - ret = i2c_atr_reserve_alias(atr); - if (ret < 0) + ret = i2c_atr_reserve_alias(atr->alias_pool); + if (ret < 0) { + dev_err(atr->dev, "failed to find a free alias\n"); return ret; + } alias = ret; @@ -336,7 +387,7 @@ static int i2c_atr_attach_addr(struct i2c_adapter *adapter, err_free: kfree(c2a); err_release_alias: - i2c_atr_release_alias(atr, alias); + i2c_atr_release_alias(atr->alias_pool, alias); return ret; } @@ -357,7 +408,7 @@ static void i2c_atr_detach_addr(struct i2c_adapter *adapter, return; } - i2c_atr_release_alias(atr, c2a->alias); + i2c_atr_release_alias(atr->alias_pool, c2a->alias); dev_dbg(atr->dev, "chan%u: detached alias 0x%02x from addr 0x%02x\n", @@ -411,12 +462,11 @@ static int i2c_atr_bus_notifier_call(struct notifier_block *nb, static int i2c_atr_parse_alias_pool(struct i2c_atr *atr) { + struct i2c_atr_alias_pool *alias_pool; struct device *dev = atr->dev; - unsigned long *alias_use_mask; size_t num_aliases; unsigned int i; u32 *aliases32; - u16 *aliases16; int ret; ret = fwnode_property_count_u32(dev_fwnode(dev), "i2c-alias-pool"); @@ -428,12 +478,23 @@ static int i2c_atr_parse_alias_pool(struct i2c_atr *atr) num_aliases = ret; - if (!num_aliases) + alias_pool = i2c_atr_alloc_alias_pool(num_aliases); + if (IS_ERR(alias_pool)) { + ret = PTR_ERR(alias_pool); + dev_err(dev, "Failed to allocate alias pool, err %d\n", ret); + return ret; + } + + atr->alias_pool = alias_pool; + + if (!alias_pool->size) return 0; aliases32 = kcalloc(num_aliases, sizeof(*aliases32), GFP_KERNEL); - if (!aliases32) - return -ENOMEM; + if (!aliases32) { + ret = -ENOMEM; + goto err_free_alias_pool; + } ret = fwnode_property_read_u32_array(dev_fwnode(dev), "i2c-alias-pool", aliases32, num_aliases); @@ -443,43 +504,27 @@ static int i2c_atr_parse_alias_pool(struct i2c_atr *atr) goto err_free_aliases32; } - aliases16 = kcalloc(num_aliases, sizeof(*aliases16), GFP_KERNEL); - if (!aliases16) { - ret = -ENOMEM; - goto err_free_aliases32; - } - for (i = 0; i < num_aliases; i++) { if (!(aliases32[i] & 0xffff0000)) { - aliases16[i] = aliases32[i]; + alias_pool->aliases[i] = aliases32[i]; continue; } dev_err(dev, "Failed to parse 'i2c-alias-pool' property: I2C flags are not supported\n"); ret = -EINVAL; - goto err_free_aliases16; - } - - alias_use_mask = bitmap_zalloc(num_aliases, GFP_KERNEL); - if (!alias_use_mask) { - ret = -ENOMEM; - goto err_free_aliases16; + goto err_free_aliases32; } kfree(aliases32); - atr->num_aliases = num_aliases; - atr->aliases = aliases16; - atr->alias_use_mask = alias_use_mask; - - dev_dbg(dev, "i2c-alias-pool has %zu aliases", atr->num_aliases); + dev_dbg(dev, "i2c-alias-pool has %zu aliases\n", alias_pool->size); return 0; -err_free_aliases16: - kfree(aliases16); err_free_aliases32: kfree(aliases32); +err_free_alias_pool: + i2c_atr_free_alias_pool(alias_pool); return ret; } @@ -500,7 +545,6 @@ struct i2c_atr *i2c_atr_new(struct i2c_adapter *parent, struct device *dev, return ERR_PTR(-ENOMEM); mutex_init(&atr->lock); - spin_lock_init(&atr->alias_mask_lock); atr->parent = parent; atr->dev = dev; @@ -520,13 +564,12 @@ struct i2c_atr *i2c_atr_new(struct i2c_adapter *parent, struct device *dev, atr->i2c_nb.notifier_call = i2c_atr_bus_notifier_call; ret = bus_register_notifier(&i2c_bus_type, &atr->i2c_nb); if (ret) - goto err_free_aliases; + goto err_free_alias_pool; return atr; -err_free_aliases: - bitmap_free(atr->alias_use_mask); - kfree(atr->aliases); +err_free_alias_pool: + i2c_atr_free_alias_pool(atr->alias_pool); err_destroy_mutex: mutex_destroy(&atr->lock); kfree(atr); @@ -543,8 +586,7 @@ void i2c_atr_delete(struct i2c_atr *atr) WARN_ON(atr->adapter[i]); bus_unregister_notifier(&i2c_bus_type, &atr->i2c_nb); - bitmap_free(atr->alias_use_mask); - kfree(atr->aliases); + i2c_atr_free_alias_pool(atr->alias_pool); mutex_destroy(&atr->lock); kfree(atr); } From patchwork Wed Jan 15 09:25:44 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Romain Gantois X-Patchwork-Id: 857794 Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [217.70.183.199]) (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 31F4E24169F; 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arc=none smtp.client-ip=217.70.183.199 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="n4xEIumD" Received: by mail.gandi.net (Postfix) with ESMTPSA id AA3B2FF80D; Wed, 15 Jan 2025 09:26:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1736933171; 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=n4xEIumDGW0l3oljFlngaBzVsCOFap2KfDtZTHcBDl03EE6CCESbNxoQxVzOFM6iB81qde b1/6B6zSREollD/DeGgmlIPsXzPZ0Zrrnqbm+kcXDJBiFnxlZrKquu+71SCphTuSFiapfB qyf15kOewwJiG0rcU+VDGVgFD5rue/6sh6DCaPGDk4JrPsQX+0AXKj+H3CV4eWaKmGI1U9 AeIG5ciq3AS6J8ufbu+EH2+epWm9ITFdmWkbzhaYCB7VeAW997Fl2OFFDuQECR+D6wUJQT /jwyNd487DCv+p3nXWoYPCt/MUuE/PcT7dR5qAJqNl8hwLhuNYN+XW4caO2UEg== From: Romain Gantois Date: Wed, 15 Jan 2025 10:25:44 +0100 Subject: [PATCH v6 7/9] i2c: support per-channel ATR alias pools Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250115-fpc202-v6-7-d47a34820753@bootlin.com> References: <20250115-fpc202-v6-0-d47a34820753@bootlin.com> In-Reply-To: <20250115-fpc202-v6-0-d47a34820753@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 15 09:25:46 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Romain Gantois X-Patchwork-Id: 857793 Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [217.70.183.199]) (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 4C730242243; Wed, 15 Jan 2025 09:26:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.199 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736933178; cv=none; b=uZObZcixjw11ag8ymwCdG04w3hTIPczcfMcd9RK7vceGRWzCHWdhU1/a83ypF4ka/476Oq2rpS1v3bFlralt+05ZAtbqA9k+CWB5ABC4wVd+I89XL1VqHHNBzGgrikex+UO0nDVMUemo0IIcTZ829qAgBW9tWA0t/l1XXywYxLA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736933178; c=relaxed/simple; bh=34F956lz7/twA0gsIXXg018rpd53zWWXWodaHPKcJOs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=oSONeEk7lBCm3R5Y1j7N3lPr42lKsWIt5Df7TzXJC7IR8DMR0uO0Icc/UjhBQi0AcYF1ywiu2gQRtGBU2SFykBSd0ILtGQORb5o0cvh97THgBFKLP5cqNFBd4cbr4MdCCgQTE3WQ6IGBeiDn/qMhu7H28Hu55uONVWjm+Fqd9Dc= 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=dM3rrIIN; arc=none smtp.client-ip=217.70.183.199 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="dM3rrIIN" Received: by mail.gandi.net (Postfix) with ESMTPSA id F0E67FF80A; Wed, 15 Jan 2025 09:26:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1736933174; 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=y+6fBkvzXwILuqk7WfTbRnQEw6uyRNDFY8eJx9IM6Jw=; b=dM3rrIINnl0MGMZzSH14waZZzdmh24uuKvlRQF4JYkVRuCmXmEJZrUcd4k/wG7IJOpCaBD FNU9P2g9c0ImgSZX5hgFRYZek1qHXseD4Fc1yH2a3nnhK/a3YgXOLU09Pb8JNX6/UDeJdK kwma3nefTV84FakeG5mzafTdPlKJ2e1KTgYnXCU//a95l3pp+U4VbxftcErSXhubGfigq+ umdZpV/JIveZDyv98vdXP1RNCSy6nFjkX1H7ylP0G0lK8WvP5jm38fBk+akQ5Ydh5E47AI cBP8l6w5taXpM/gH9KHJh3jVH869mVfbUHtAvhfIzvPujG4D2Nxn0lyYmrMphg== From: Romain Gantois Date: Wed, 15 Jan 2025 10:25:46 +0100 Subject: [PATCH v6 9/9] misc: add FPC202 dual port controller driver Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250115-fpc202-v6-9-d47a34820753@bootlin.com> References: <20250115-fpc202-v6-0-d47a34820753@bootlin.com> In-Reply-To: <20250115-fpc202-v6-0-d47a34820753@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. Reviewed-by: Linus Walleij 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..df5a97ebfaa15b50e23caa90b466a127c6dd64fa 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);