From: Robert Keevil <rkeevil_at_gmail.com>
Date: Sat, 20 Jun 2009 21:13:16 -0500

Hi,

I've had some success this week (as I'm becoming a little more familiar
and comfortable with ARM assembler) in locating the LCD code in the OF
bootloader. To my eye it looks like the View writes to its LCD in a
fairly similar fashion to the e200v1, using 3 GPIOs to write one bit at
a time to the LCD.

For the 01.01.06a bootloader:

offset - function
0x5CC8 - lcd_init_gpio
0x6278 - lcd_write_reg
0x643C - backlight_on/_off(r1)
0x645C - lcd_send_msg
0x6478 - lcd_send_byte

The LCD seems to be hooked up to GPIOH as follows:

#define LCD_DATA_OUT_GPIO GPIOH_OUTPUT_VAL
#define LCD_DATA_OUT_PIN 4

#define LCD_CLOCK_GPIO GPIOH_OUTPUT_VAL
#define LCD_CLOCK_PIN 6

#define LCD_CS_GPIO GPIOH_OUTPUT_VAL
#define LCD_CS_PIN 7

but I've not had any luck in getting anything to display after modifying
an e200 build (updating the e200 LCD driver as required, changing the
DRAMORIG to 0x10f00000 and changing LCD_WIDTH/LCD_HEIGHT). Since it
looks so similar to the e200 (at least to me) is it safe to assume that
the View is likely to contain another Renesas LCD controller? What is
the best way to try and pin-point which model is in use? (The HD66789
in the e200 is limited to 176x220 - the HD66776 and HD66781 are
possibilities for 240x320, but they produced several other controllers
after those).
Since Rockbox code runs after the OF bootloader, how much hardware
initialisation is required to get the LCD up and running? On the e200
RB inits the GPIOs and LCD controller again.
I would appreciate any tips, advice or insight!

Cheers

Robert
Received on 2009-06-21