Re: [PATCH 2.6.19-rc1 V9] drivers: add LCD support

Hi!

Andrew, I think this can be the final review.
Updated to 2.6.19-rc1. Please apply.

No, I'm sorry. And I have to apologize for being blind.

I was going to say 'this is very important, because cellphones *do*
have secondary displays, and we want to use them'. And yes it is
important, but you got the interface wrong.


+ The cfag12864b LCD driver defines two ways to communicate
+ with the lcd.
+
+ 1. Use seek and write syscalls. Bytes written appear on
+ the screen without any formatting on the position pointed
+ by the file offset.
+
+ It is hardware dependent. It should be use to modify
+ specific display's pixels to achieve higher refreshing
+ rates.
+
+ 2. Use ioctl syscall. The magic number is 0xFF.
+ There are four ioctls:
+
+ 2.0. off _IO(0xFF,0)
+
+ Power off display.
+
+ It doesn't clear the display.
+ It doesn't stop the controllers.
+
+ 2.1. on _IO(0xFF,1)
+
+ Power on display.
+
+ 2.2. clear _IO(0xFF,2)
+
+ Clear the display.
+
+ 2.3. format _IOW(0xFF,3,void *)
+
+ Read the given buffer, transform it to the hardware
+ dependent format and show it on the screen.
+
+ The argument must point to a userspace buffer of
+ size 128*64 bytes (the display's size).
+
+ Each buffer's byte (unsigned) represent a pixel:
+ 0 = pixel will turn off
+ >0 = pixel will turn on
+
+ For more information and examples, see
+ Documentation/auxdisplay/cfag12864b

So you have 128x64 pixels b/w display, and invented completely new
interface to control it.

Fortunately we already have good interface for the display... It is
called fbcon, and is more flexible than 128x64 b/w... but can do
128x64 b/w just fine.

Please use it. It is way more flexible, and it is right thing to do.

Pavel
--
Thanks for all the (sleeping) penguins.
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