iris/boot-programs/lcd.ccp

#pypp 0
// Iris: micro-kernel for a capability-based operating system.
// boot-programs/lcd.ccp: Display driver.
// Copyright 2009 Bas Wijnen <wijnen@debian.org>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include "devices.hh"
#define ARCH
#include "arch.hh"

// Pin definitions, all in port 2.
#define PWM_ENABLE (1 << 30)
#define SPEN    (1 << 0)       //LCD_SPL
#define SPCK    (1 << 1)       //LCD_CLS
#define SPDA    (1 << 2)       //LCD_PS
#define LCD_RET (1 << 3)       //LCD_REV //use for lcd reset

static void set_backlight (bool state):
	if state:
		PWM_DUT (0) = 300
		PWM_CTR (0) = 0xbf
		GPIO_GPDR (2) |= PWM_ENABLE
	else:
		PWM_DUT (0) = 0
		PWM_CTR (0) = 0x3f
		GPIO_GPDR (2) &= ~PWM_ENABLE

static void reset ():
	PWM_PER (0) = 300
	set_backlight (false)

	// initialize things.
	GPIO_GPIER (2) &= ~(PWM_ENABLE | LCD_RET | SPEN | SPCK | SPDA)
	GPIO_GPDIR (2) |= PWM_ENABLE | LCD_RET | SPEN | SPCK | SPDA
	udelay (50)
	GPIO_GPDR (2) &= ~LCD_RET
	ddelay (2)
	GPIO_GPDR (2) |= LCD_RET
	ddelay (1)

	// For now, support only 16 bpp.
	// Screen is 800x480 tft.
	unsigned h = 800, v = 480, hs = 80, vs = 20, fps = 60, Bpp = 2
	LCD_CTRL = LCD_CTRL_BPP_16 | LCD_CTRL_BST_16
	LCD_VSYNC = vs
	LCD_HSYNC = hs
	LCD_DAV = (vs << 16) | (vs + v)
	LCD_DAH = (hs << 16) | (hs + h)
	LCD_VAT = ((hs + h) << 16) | (vs + v)
	#define MODE_TFT_GEN 0
	#define PCLK_N (1 << 10)
	#define VSYNC_N (1 << 8)
	LCD_CFG = MODE_TFT_GEN | PCLK_N | VSYNC_N

	cpm_stop_lcd ()

	unsigned pllout = cpm_get_pllout ()
	unsigned pixclock = fps * (hs + h) * (vs + v)
	CPM_CFCR2 = pllout / pixclock - 1

	unsigned val = pllout / (pixclock * 4) - 1
	while val < 0xf && pllout / (val + 1) > 150000000:
		++val
	cpm_set_lcdclk_div (val)
	CPM_CFCR |= CPM_CFCR_UPE

	cpm_start_lcd ()

	udelay (1000)
	//LCD_DA0 = framebuffer
	unsigned frame_size = v * h * Bpp
	LCD_CMD0 = LCD_CMD_SOFINT | LCD_CMD_EOFINT | (frame_size << LCD_CMD_LEN_BIT)
	lcd_set_ena ()
	lcd_enable_eof_intr ()

int main ():
	map_gpio ()
	map_pwm0 ()
	map_lcd ()
	map_cpm ()

	reset ()
	register_interrupt (IRQ_LCD)
	set_backlight (true)

	while true:
		Message msg
		if !wait (&msg):
			continue
		switch msg.protected_data:
			case IRQ_LCD:
				kdebug (0)
				LCD_STATE &= ~LCD_STATE_EOF
				register_interrupt (IRQ_LCD)
				// TODO: allow callback
				break
			case LCD_BACKLIGHT:
				set_backlight (msg.data[0])
				break
			case LCD_RESET:
				reset ()
				break