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"

#define assert(x) do { while (!(x)) kdebug (0, 0); } while (0)

// For now, support only 16 bpp.
// Screen is 800x480 tft.
unsigned h = 800, v = 480, hs = 80, vs = 20, fps = 60, Bpp = 2
#define frame_size (v * h * Bpp)

// 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

struct Descriptor:
	unsigned next
	unsigned frame
	unsigned id
	unsigned cmd

static void reset (unsigned physical_descriptor):
	PWM_PER (0) = 300
	set_backlight (true)

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

	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 VSYNC_N (1 << 8)
	LCD_CFG = MODE_TFT_GEN | VSYNC_N

	cpm_stop_lcd ()

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

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

	cpm_start_lcd ()

	udelay (1000)
	LCD_DA0 = physical_descriptor
	lcd_set_ena ()
	lcd_enable_eof_intr ()

int main ():
	// TODO: The descriptor takes an entire uncached page, because I don't know how to force a cache write-back.  It's much better to do that instead.
	map_gpio ()
	map_pwm0 ()
	map_lcd ()
	map_cpm ()

	unsigned pages = (frame_size + 16 + ~PAGE_MASK) >> PAGE_BITS
	assert (pages > CAPPAGE_SIZE && pages <= 2 * CAPPAGE_SIZE)
	unsigned physical = alloc_range (__my_memory, pages)
	assert (physical)
	//Capability cappage[2]
	//unsigned base[2]
	//cappage[0] = memory_create_cappage (__my_memory, &base[0])
	//cappage[1] = memory_create_cappage (__my_memory, &base[1])
	for unsigned i = 0; i < CAPPAGE_SIZE; ++i:
		Capability page = memory_create_page (__my_memory)
		//cappage_set (cappage[0], page, i)
		alloc_physical (page, physical + i * PAGE_SIZE, 0, 1)
		memory_map (__my_memory, page, (unsigned)LCD_FRAMEBUFFER_BASE + i * PAGE_SIZE, 1)
		drop (page)
	for unsigned i = 0; i < pages - CAPPAGE_SIZE; ++i:
		Capability page = memory_create_page (__my_memory)
		//cappage_set (cappage[1], page, i)
		alloc_physical (page, physical + (i + CAPPAGE_SIZE) * PAGE_SIZE, 0, 1)
		memory_map (__my_memory, page, (unsigned)LCD_FRAMEBUFFER_BASE + (i + CAPPAGE_SIZE) * PAGE_SIZE, 1)
		drop (page)
	unsigned og = 0
	for unsigned y = 0; y < 480; ++y:
		unsigned g = (y << 6) / 480
		if g != og:
			og = g
			g = 0x3f
		unsigned olr = 0, ob = ((25 * y * y) << 5) / (9 * 800 * 800 + 25 * 480 * 480)
		for unsigned x = 0; x < 800; ++x:
			unsigned r = (x << 5) / 800
			unsigned b = ((9 * x * x + 25 * y * y) << 5) / (9 * 800 * 800 + 25 * 480 * 480)
			if r != olr:
				olr = r
				r = 0x1f
			unsigned oyb = b
			if y > 0:
				oyb = ((9 * x * x + 25 * (y - 1) * (y - 1)) << 5) / (9 * 800 * 800 + 25 * 480 * 480)
			if b != ob || b != oyb:
				ob = b
				b = 0x1f
			LCD_FRAMEBUFFER_BASE[y * 800 + x] = (r << 11) | (g << 5) | (b)
	Descriptor *descriptor = (Descriptor *)((unsigned)LCD_FRAMEBUFFER_BASE + frame_size)
	unsigned physical_descriptor = physical + frame_size
	descriptor->next = physical_descriptor
	descriptor->frame = physical
	descriptor->id = 0xdeadbeef
	descriptor->cmd = LCD_CMD_EOFINT | ((frame_size / 4) << LCD_CMD_LEN_BIT)
	reset (physical_descriptor)
	register_interrupt (IRQ_LCD)
	set_backlight (true)

	while true:
		Message msg
		wait (&msg)
		switch msg.protected_data:
			case IRQ_LCD:
				lcd_clr_eof ()
				register_interrupt (IRQ_LCD)
				// TODO: allow callback
				break
			#if 0
			case LCD_BACKLIGHT:
				set_backlight (msg.data[0])
				break
			case LCD_RESET:
				//reset (physical_descriptor)
				break
			#endif