From: "Noralf Trønnes" <noralf@tronnes.org>
To: Stephen Warren <swarren@wwwdotorg.org>, Eric Anholt <eric@anholt.net>
Cc: devicetree@vger.kernel.org, linux-rpi-kernel@lists.infradead.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/3 v2] ARM: bcm2835: Add the Raspberry Pi firmware driver
Date: Fri, 29 May 2015 00:40:24 +0200 [thread overview]
Message-ID: <55679958.8010003@tronnes.org> (raw)
In-Reply-To: <556785D8.2090709@wwwdotorg.org>
Den 28.05.2015 23:17, skrev Stephen Warren:
> On 05/13/2015 01:00 PM, Eric Anholt wrote:
>> This gives us a function for making mailbox property channel requests
>> of the firmware, which is most notable in that it will let us get and
>> set clock rates.
> ...
>> Note that I don't think I've done what srwarren wanted for
>> -EPROBE_DEFER, because I'm not clear what he wants. I think he might
>> just be asking for a function that does:
>>
>> /*
>> * Returns 0 if the firmware device is probed and available, otherwise
>> * -EPROBE_DEFER.
>> */
>> int rpi_firmware_get(struct device_node *firmware_node)
>> {
>> struct platform_device *pdev = of_find_device_by_node(of_node);
>> if (!platform_get_drvdata(pdev))
of_find_device_by_node() can return NULL if the device can't be found.
platform_get_drvdata() can't handle a NULL pointer.
>> return -EPROBE_DEFER;
>> return 0;
>> }
>> EXPORT_SYMBOL(rpi_firmware_get)
>>
>> If that's all, I'm happy to add it.
> Yes, there definitely needs to be something that clients can call at
> probe() time to make sure the firmware driver is there already. That
> check is quite different from actually sending a request to the FW, so
> I'd certainly expect a separate function for that.
A try_module_get() here would make sure this module won't go away while a
client relies on it. For that we would need a rpi_firmware_put() as well.
next prev parent reply other threads:[~2015-05-28 22:40 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-13 19:00 RPi firmware driver v2 Eric Anholt
2015-05-13 19:00 ` [PATCH 1/3 v2] dt/bindings: Add binding for the Raspberry Pi firmware driver Eric Anholt
2015-05-14 8:40 ` Lee Jones
2015-05-14 9:57 ` Eric Anholt
2015-05-17 17:11 ` Noralf Trønnes
2015-05-18 17:59 ` [PATCH 1/3 v3] " Eric Anholt
2015-05-28 21:12 ` Stephen Warren
2015-05-13 19:00 ` [PATCH 2/3 v2] ARM: bcm2835: Add " Eric Anholt
2015-05-17 17:30 ` Noralf Trønnes
2015-05-17 18:26 ` Noralf Trønnes
2015-05-18 17:34 ` Eric Anholt
2015-05-18 18:00 ` [PATCH 2/3 v3] " Eric Anholt
[not found] ` <20150528112610.GO11677@x1>
2015-05-28 11:45 ` [PATCH 2/3 v2] " Lee Jones
2015-05-28 18:33 ` [PATCH 2/3 v4] " Eric Anholt
2015-05-28 21:28 ` Stephen Warren
2015-05-28 21:39 ` Noralf Trønnes
2015-05-28 22:09 ` Stephen Warren
2015-05-28 22:36 ` Eric Anholt
2015-05-28 21:42 ` Noralf Trønnes
2015-05-28 22:10 ` Stephen Warren
2015-05-28 22:38 ` Eric Anholt
2015-05-28 22:43 ` Noralf Trønnes
2015-05-28 21:17 ` [PATCH 2/3 v2] " Stephen Warren
2015-05-28 22:40 ` Noralf Trønnes [this message]
2015-05-13 19:00 ` [PATCH 3/3 v2] ARM: bcm2835: Add the firmware driver information to the RPi DT Eric Anholt
2015-05-28 21:29 ` Stephen Warren
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