From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (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 9CB2042AA1; Tue, 18 Mar 2025 15:24:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742311499; cv=none; b=mWCXR/TcZsu8dOB6xLUENmYitvspsR0ZJ2vZFWgVQ92WvPV8RqJ/7PJvdxSINvBoThZIoe4IKfzWdQaCH3GDdH5E3aHSitG4ifotfb9cnYFOoV8eIXnWtzlCg3d2W1zz5TDTb7IGjBOXjrtYAOKzs4mJwYGo8WQl6x9Ukl/IOjk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742311499; c=relaxed/simple; bh=/Vxtk/M/zsYmwadz5SgxJ5mP+fz1qKWq85EWjMZiyDo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=H/U8Cak+/BKD0HvHAyeouGd4MJt3LlLRjx6f+PaBLom5Bj5paXyoLge7Uph/36woz+eziAcVPRO7s12ZIMoQ97XsHqG4+IdKCk/21HUgK7Sqs1u4az8dEDkD6/BkdR+nfkJVrs1SrI88Bne1aaHGa4CI0dS3ScgCU95V9Q7Engs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=cHmBZ1RF; arc=none smtp.client-ip=192.198.163.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="cHmBZ1RF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1742311493; x=1773847493; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=/Vxtk/M/zsYmwadz5SgxJ5mP+fz1qKWq85EWjMZiyDo=; b=cHmBZ1RFSRqe4FUE5X+nAlMFWrBarJHKUUCo1ZnXcv5rKPZwXYxFcIDc OyeMFEMjPOQNtt5gXueGH47KywBKLYIHn/VcsyghrNCdJWp/ZLhIJ7X6j 9SA6GAcSQVCnK7hssZZqzAq4aTt8FBEuJ5Zs2fMPJdQbNi/w20Ule638h WUG6LkBphcdeHv7myEgcUehy0Wi1B9Bi4RpwJcMhdXywfZE5593xeYhc1 wPH1fEjnBFzRXANhMsGuOfQu2Z3pQyWiZWZ72JDEXF7mdZ65fpsfKeCD/ QXnJwQcTWTUQ2cWb4KoSyleC49n0kF7KiAOGCwCGECbv1HqJqGGzBjHhO A==; X-CSE-ConnectionGUID: 9w61opJDRF+XTadj9AwZGQ== X-CSE-MsgGUID: +64MRf30QU6k6pS7L84zkg== X-IronPort-AV: E=McAfee;i="6700,10204,11377"; a="54135685" X-IronPort-AV: E=Sophos;i="6.14,257,1736841600"; d="scan'208";a="54135685" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Mar 2025 08:24:52 -0700 X-CSE-ConnectionGUID: kMdL4c7YRZKiJ3gE8xKbMw== X-CSE-MsgGUID: fO2F/3zYQOS+T4NonmXKdw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.14,257,1736841600"; d="scan'208";a="122233599" Received: from turnipsi.fi.intel.com (HELO kekkonen.fi.intel.com) ([10.237.72.44]) by orviesa010-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Mar 2025 08:24:48 -0700 Received: from kekkonen.localdomain (localhost [127.0.0.1]) by kekkonen.fi.intel.com (Postfix) with SMTP id 95F1711F9BD; Tue, 18 Mar 2025 17:24:44 +0200 (EET) Date: Tue, 18 Mar 2025 15:24:44 +0000 Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo From: Sakari Ailus To: Matti Vaittinen Cc: Matti Vaittinen , Jonathan Cameron , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Andy Shevchenko , Daniel Scally , Heikki Krogerus , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Claudiu Manoil , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH v8 02/10] property: Add functions to iterate named child Message-ID: References: <9c3880f74476436f39d796b5c10c540ae50b722c.1742225817.git.mazziesaccount@gmail.com> Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9c3880f74476436f39d796b5c10c540ae50b722c.1742225817.git.mazziesaccount@gmail.com> Moi, On Mon, Mar 17, 2025 at 05:50:38PM +0200, Matti Vaittinen wrote: > There are a few use-cases where child nodes with a specific name need to > be parsed. Code like: > > fwnode_for_each_child_node() > if (fwnode_name_eq()) > ... > > can be found from a various drivers/subsystems. Adding a macro for this > can simplify things a bit. > > In a few cases the data from the found nodes is later added to an array, > which is allocated based on the number of found nodes. One example of > such use is the IIO subsystem's ADC channel nodes, where the relevant > nodes are named as channel[@N]. > > Add helpers for iterating and counting device's sub-nodes with certain > name instead of open-coding this in every user. > > Suggested-by: Jonathan Cameron > Signed-off-by: Matti Vaittinen > Reviewed-by: Andy Shevchenko > Reviewed-by: Marcelo Schmitt > --- > Revision history: > v7 => v8: > - Fix the example in fwnode_get_named_child_node_count() documentation > to use the fwnode_get_named_child_node_count() and not the > device_get_named_child_node_count() > - Fix the rest of the new macro's indentiations > v6 => v7: > - Improve kerneldoc > - Inline device_get_named_child_node_count() and change it to call > fwnode_get_named_child_node_count() inside > - Fix indentiation of the new macros > v5 => v6: > - Add helpers to also iterate through the nodes. > v4 => v5: > - Use given name instead of string 'channel' when counting the nodes > - Add also fwnode_get_child_node_count_named() as suggested by Rob. > v3 => v4: > - New patch as suggested by Jonathan, see discussion in: > https://lore.kernel.org/lkml/20250223161338.5c896280@jic23-huawei/ > --- > drivers/base/property.c | 27 +++++++++++++++++++++++++++ > include/linux/property.h | 24 ++++++++++++++++++++++++ > 2 files changed, 51 insertions(+) > > diff --git a/drivers/base/property.c b/drivers/base/property.c > index c1392743df9c..f42f32ff45fc 100644 > --- a/drivers/base/property.c > +++ b/drivers/base/property.c > @@ -945,6 +945,33 @@ unsigned int device_get_child_node_count(const struct device *dev) > } > EXPORT_SYMBOL_GPL(device_get_child_node_count); > > +/** > + * fwnode_get_named_child_node_count - number of child nodes with given name > + * @fwnode: Node which child nodes are counted. > + * @name: String to match child node name against. > + * > + * Scan child nodes and count all the nodes with a specific name. Potential > + * 'number' -ending after the 'at sign' for scanned names is ignored. > + * E.g.:: > + * fwnode_get_named_child_node_count(fwnode, "channel"); > + * would match all the nodes:: > + * channel { }, channel@0 {}, channel@0xabba {}... > + * > + * Return: the number of child nodes with a matching name for a given device. > + */ > +unsigned int fwnode_get_named_child_node_count(const struct fwnode_handle *fwnode, > + const char *name) > +{ > + struct fwnode_handle *child; > + unsigned int count = 0; > + > + fwnode_for_each_named_child_node(fwnode, child, name) > + count++; > + > + return count; > +} > +EXPORT_SYMBOL_GPL(fwnode_get_named_child_node_count); > + > bool device_dma_supported(const struct device *dev) > { > return fwnode_call_bool_op(dev_fwnode(dev), device_dma_supported); > diff --git a/include/linux/property.h b/include/linux/property.h > index e214ecd241eb..a1856e6b714c 100644 > --- a/include/linux/property.h > +++ b/include/linux/property.h > @@ -167,10 +167,18 @@ struct fwnode_handle *fwnode_get_next_available_child_node( > for (child = fwnode_get_next_child_node(fwnode, NULL); child; \ > child = fwnode_get_next_child_node(fwnode, child)) > > +#define fwnode_for_each_named_child_node(fwnode, child, name) \ > + fwnode_for_each_child_node(fwnode, child) \ > + if (!fwnode_name_eq(child, name)) { } else > + > #define fwnode_for_each_available_child_node(fwnode, child) \ > for (child = fwnode_get_next_available_child_node(fwnode, NULL); child;\ > child = fwnode_get_next_available_child_node(fwnode, child)) > > +#define fwnode_for_each_available_named_child_node(fwnode, child, name) \ > + fwnode_for_each_available_child_node(fwnode, child) \ > + if (!fwnode_name_eq(child, name)) { } else > + OF only enumerates available nodes via the fwnode API, software nodes don't have the concept but on ACPI I guess you could have a difference in nodes where you have device sub-nodes that aren't available. Still, these ACPI device nodes don't have meaningful names in this context (they're 4-character object names) so you wouldn't use them like this anyway. So my question is: is it useful to provide this besides fwnode_for_each_named_child_node(), given that both are effectively the same? > struct fwnode_handle *device_get_next_child_node(const struct device *dev, > struct fwnode_handle *child); > > @@ -178,11 +186,19 @@ struct fwnode_handle *device_get_next_child_node(const struct device *dev, > for (child = device_get_next_child_node(dev, NULL); child; \ > child = device_get_next_child_node(dev, child)) > > +#define device_for_each_named_child_node(dev, child, name) \ > + device_for_each_child_node(dev, child) \ > + if (!fwnode_name_eq(child, name)) { } else > + > #define device_for_each_child_node_scoped(dev, child) \ > for (struct fwnode_handle *child __free(fwnode_handle) = \ > device_get_next_child_node(dev, NULL); \ > child; child = device_get_next_child_node(dev, child)) > > +#define device_for_each_named_child_node_scoped(dev, child, name) \ > + device_for_each_child_node_scoped(dev, child) \ > + if (!fwnode_name_eq(child, name)) { } else > + > struct fwnode_handle *fwnode_get_named_child_node(const struct fwnode_handle *fwnode, > const char *childname); > struct fwnode_handle *device_get_named_child_node(const struct device *dev, > @@ -210,6 +226,14 @@ int fwnode_irq_get_byname(const struct fwnode_handle *fwnode, const char *name); > > unsigned int device_get_child_node_count(const struct device *dev); > > +unsigned int fwnode_get_named_child_node_count(const struct fwnode_handle *fwnode, > + const char *name); > +static inline unsigned int device_get_named_child_node_count(const struct device *dev, > + const char *name) > +{ > + return fwnode_get_named_child_node_count(dev_fwnode(dev), name); > +} > + > static inline int device_property_read_u8(const struct device *dev, > const char *propname, u8 *val) > { -- Terveisin, Sakari Ailus