From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
To: Vinod Koul <vinod.koul@intel.com>, Mark Brown <broonie@kernel.org>
Cc: ALSA <alsa-devel@alsa-project.org>,
Charles Keepax <ckeepax@opensource.cirrus.com>,
Sudheer Papothi <spapothi@codeaurora.org>,
Takashi <tiwai@suse.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
plai@codeaurora.org, LKML <linux-kernel@vger.kernel.org>,
patches.audio@intel.com, srinivas.kandagatla@linaro.org,
Shreyas NC <shreyas.nc@intel.com>,
Sanyog Kale <sanyog.r.kale@intel.com>,
Sagar Dharia <sdharia@codeaurora.org>,
alan@linux.intel.com
Subject: Re: [PATCH 04/14] soundwire: Add MIPI DisCo property helpers
Date: Sun, 22 Oct 2017 15:44:47 +0530 [thread overview]
Message-ID: <bfbe69a1-e1dd-de1a-52b9-8de48190bc0b@linux.intel.com> (raw)
In-Reply-To: <20171021113718.GG30097@localhost>
On 10/21/17 5:07 PM, Vinod Koul wrote:
> On Sat, Oct 21, 2017 at 10:20:46AM +0100, Mark Brown wrote:
>> On Thu, Oct 19, 2017 at 08:33:20AM +0530, Vinod Koul wrote:
>>
>>> + /* device is probed so let's read the properties now */
>>> + if (slave->ops && slave->ops->read_prop)
>>> + slave->ops->read_prop(slave);
>>
>> Is it valid for us to not be able to read the properties?
>
> Practically no. Without the values bus wont work
The notion of read is a bit overloaded here. What is needed is that the
information is provided to the bus, whether you read it from firmware or
a table in the codec driver is an implementation choice - see below.
>
>>
>>> + fwnode_property_read_u32(node, "mipi-sdw-port-max-wordlength",
>>> + &dpn[i].max_word);
>>> + fwnode_property_read_u32(node, "mipi-sdw-port-min-wordlength",
>>> + &dpn[i].min_word);
>>
>> Don't we know this stuff simply by virtue of knowing what device we're
>> talking to (given that there aren't class devices)?
>
> Well I think the spec is midway to device class so they added it to make it
> generic :)
The properties are needed so that the bus can perform all the
transport-related stuff. As explained in the patches, we are not making
assumptions on how the codec driver is written, the implementation can
either get the properties from firmware (DT or ACPI) or hard-code them
in the driver.
The only property that needs to be defined is for multi-lane setups,
since the topology is not known to a codec driver.
next prev parent reply other threads:[~2017-10-22 10:14 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-19 3:03 [PATCH 00/14] soundwire: Add a new SoundWire subsystem Vinod Koul
2017-10-19 3:03 ` [PATCH 01/14] Documentation: Add SoundWire summary Vinod Koul
2017-10-19 3:33 ` Randy Dunlap
2017-10-19 4:44 ` Vinod Koul
2017-10-20 10:39 ` Greg Kroah-Hartman
2017-10-20 15:49 ` Vinod Koul
2017-10-20 16:22 ` Greg Kroah-Hartman
2017-10-20 17:09 ` Vinod Koul
2017-10-21 8:57 ` Mark Brown
2017-10-21 11:28 ` Vinod Koul
2017-10-22 10:06 ` [alsa-devel] " Pierre-Louis Bossart
2017-10-23 8:21 ` Mark Brown
2017-10-23 7:50 ` Mark Brown
2017-10-23 11:18 ` [alsa-devel] " Vinod Koul
2017-10-19 3:03 ` [PATCH 02/14] soundwire: Add SoundWire bus type Vinod Koul
2017-10-19 7:40 ` Takashi Iwai
2017-10-19 8:32 ` Takashi Iwai
2017-10-20 5:11 ` Vinod Koul
2017-10-20 6:59 ` Takashi Iwai
2017-10-20 15:46 ` Vinod Koul
2017-10-20 15:50 ` Takashi Iwai
2017-10-20 16:11 ` Vinod Koul
2017-10-20 10:41 ` Greg Kroah-Hartman
2017-10-20 15:52 ` Vinod Koul
2017-10-20 10:45 ` Greg Kroah-Hartman
2017-10-20 16:01 ` Vinod Koul
2017-10-20 16:21 ` Greg Kroah-Hartman
2017-10-20 17:10 ` Vinod Koul
2017-10-23 11:46 ` Alan Cox
2017-10-26 8:33 ` Vinod Koul
2017-10-27 8:57 ` Greg Kroah-Hartman
2017-10-30 13:11 ` Vinod Koul
2017-10-20 16:03 ` Philippe Ombredanne
2017-10-20 16:20 ` Vinod Koul
2017-10-20 16:27 ` Greg Kroah-Hartman
2017-10-20 17:13 ` Vinod Koul
2017-10-23 11:52 ` Alan Cox
2017-10-21 9:03 ` Mark Brown
2017-10-21 11:29 ` Vinod Koul
2017-11-09 21:14 ` Srinivas Kandagatla
2017-11-10 4:59 ` Vinod Koul
2017-11-10 8:55 ` Vinod Koul
2017-11-10 10:50 ` Srinivas Kandagatla
2017-11-10 10:42 ` Srinivas Kandagatla
2017-11-10 10:58 ` Vinod Koul
2017-10-19 3:03 ` [PATCH 03/14] soundwire: Add Master registration Vinod Koul
2017-10-19 8:54 ` Takashi Iwai
2017-10-20 5:19 ` Vinod Koul
2017-10-20 10:47 ` Greg Kroah-Hartman
2017-10-20 16:05 ` Vinod Koul
2017-10-21 9:12 ` Mark Brown
2017-10-21 11:35 ` Vinod Koul
2017-10-23 8:24 ` Mark Brown
2017-10-23 11:19 ` Vinod Koul
2017-11-09 21:14 ` Srinivas Kandagatla
2017-11-10 5:02 ` Vinod Koul
2017-10-19 3:03 ` [PATCH 04/14] soundwire: Add MIPI DisCo property helpers Vinod Koul
2017-10-19 9:02 ` [alsa-devel] " Takashi Iwai
2017-10-20 5:25 ` Vinod Koul
2017-10-21 9:20 ` Mark Brown
2017-10-21 11:37 ` Vinod Koul
2017-10-22 10:14 ` Pierre-Louis Bossart [this message]
2017-10-19 3:03 ` [PATCH 05/14] soundwire: Add SoundWire MIPI defined registers Vinod Koul
2017-10-19 3:03 ` [PATCH 06/14] soundwire: Add IO transfer Vinod Koul
2017-10-19 9:13 ` [alsa-devel] " Takashi Iwai
2017-10-20 5:30 ` Vinod Koul
2017-10-20 7:06 ` Takashi Iwai
2017-10-20 15:48 ` [alsa-devel] " Vinod Koul
2017-10-21 9:29 ` Mark Brown
2017-10-21 11:40 ` Vinod Koul
2017-10-19 3:03 ` [PATCH 07/14] regmap: Add SoundWire bus support Vinod Koul
2017-10-21 9:34 ` Mark Brown
2017-10-21 11:44 ` Vinod Koul
2017-10-23 11:56 ` Alan Cox
2017-10-23 13:16 ` Mark Brown
2017-10-19 3:03 ` [PATCH 08/14] soundwire: Add Slave status handling helpers Vinod Koul
2017-10-19 13:44 ` [alsa-devel] " Takashi Iwai
2017-10-31 13:04 ` Vinod Koul
2017-10-31 21:19 ` Pierre-Louis Bossart
2017-11-01 9:08 ` Vinod Koul
2017-11-01 21:10 ` [alsa-devel] " Pierre-Louis Bossart
2017-11-02 3:28 ` Vinod Koul
2017-10-19 3:03 ` [PATCH 09/14] soundwire: Add slave status handling Vinod Koul
2017-10-19 3:03 ` [PATCH 10/14] soundwire: Add sysfs for SoundWire DisCo properties Vinod Koul
2017-10-21 9:42 ` Mark Brown
2017-10-21 11:53 ` Vinod Koul
2017-11-09 21:14 ` Srinivas Kandagatla
2017-11-10 4:52 ` Vinod Koul
2017-10-19 3:03 ` [PATCH 11/14] soundwire: cdns: Add cadence module Vinod Koul
2017-10-21 9:52 ` Mark Brown
2017-10-21 11:54 ` Vinod Koul
2017-10-19 3:03 ` [PATCH 12/14] soundwire: cdns: Add sdw_master_ops and IO transfer support Vinod Koul
2017-10-19 3:03 ` [PATCH 13/14] soundwire: intel: Add Intel Master driver Vinod Koul
2017-10-19 3:03 ` [PATCH 14/14] soundwire: intel: Add Intel init module Vinod Koul
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