From: timur@freescale•com (Timur Tabi)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM: vexpress: initial device tree support
Date: Tue, 10 Jan 2012 18:28:44 -0600 [thread overview]
Message-ID: <4F0CD7BC.7080409@freescale.com> (raw)
In-Reply-To: <4F0CBD46.2010909@firmworks.com>
Mitch Bradley wrote:
> It seems to me that having the framebuffer driver handle the EDID
> "driver" function is exactly the right thing. The framebuffer driver is
> the only thing that cares about EDID information. Given a phandle
> reference to an I2C interface, the "driver" is just "call the I2C read
> routine" - plus, in your case, toggling the GPIO pin.
Do you think I should have the I2C probe function read the EDID data, and then store it in some global variable? That won't work if I have multiple video controllers, since I won't know which EDID data goes with which video controller. I tried adding a call to i2c_add_driver() in my framebuffer driver, but the I2C probe function was called *after* the framebuffer's probe function, so that doesn't help me.
> That GPIO pin thing is annoying, but not sufficiently complex or common
> that it warrants having a separate EDID driver. You could define a
> platform-specific property to tell your framebuffer driver that it needs
> to do that GPIO thing. It's a hack, but the GPIO thing is inherently a
> hack, so there will be some ugliness somewhere as a result.
I have two platform-specific functions, "enabled_edid" and "disable_edid", that I call before/after calling fb_ddc_read(). This seems to work well, and I already have a mechanism for calling platform-specific functions from the framebuffer driver.
However, Stephen Warren said I should be using the I2C mux feature instead.
--
Timur Tabi
Linux kernel developer at Freescale
next prev parent reply other threads:[~2012-01-11 0:28 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-21 9:19 [PATCH] ARM: vexpress: initial device tree support Dave Martin
2011-09-21 13:24 ` Rob Herring
2011-09-21 14:24 ` Dave Martin
2011-09-21 14:33 ` Pawel Moll
2011-09-21 15:49 ` Dave Martin
2011-09-21 14:57 ` Grant Likely
2011-09-21 16:01 ` Pawel Moll
2011-09-21 16:17 ` Dave Martin
2011-09-21 16:28 ` Pawel Moll
2011-09-21 16:37 ` Rob Herring
2011-09-21 17:15 ` Dave Martin
2011-09-21 17:47 ` Mitch Bradley
2011-09-22 12:19 ` Dave Martin
2012-01-09 23:26 ` Tabi Timur-B04825
2012-01-10 0:42 ` Mitch Bradley
2012-01-10 2:24 ` Tabi Timur-B04825
2012-01-10 12:22 ` Jamie Lokier
2012-01-10 21:58 ` Timur Tabi
2012-01-10 22:35 ` Mitch Bradley
2012-01-10 23:55 ` Stephen Warren
2012-01-11 0:02 ` Timur Tabi
2012-01-11 0:28 ` Timur Tabi [this message]
2012-01-11 6:43 ` Mitch Bradley
2012-01-11 20:17 ` Timur Tabi
2012-01-11 23:20 ` Mitch Bradley
2012-01-11 23:32 ` Timur Tabi
2012-01-11 20:29 ` Stephen Warren
2012-01-11 20:32 ` Timur Tabi
2012-01-11 20:36 ` Stephen Warren
2012-01-11 21:37 ` Timur Tabi
2012-01-11 21:57 ` Stephen Warren
2012-01-12 12:24 ` Jamie Lokier
2012-01-12 16:49 ` Stephen Warren
2012-01-11 23:16 ` Mitch Bradley
2012-01-12 0:15 ` Stephen Warren
2012-01-12 0:38 ` Mitch Bradley
2012-01-12 0:47 ` Mitch Bradley
2012-01-12 16:45 ` Stephen Warren
2012-01-12 12:09 ` Jamie Lokier
2012-01-12 16:52 ` Stephen Warren
2012-01-10 11:04 ` Dave Martin
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