#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"

__asm__ volatile (".section .rodata\n.globl charset\ncharset:\n.incbin \"boot-programs/charset.data\"\n.section .text")
// charset is really the first character in the array.  Its address is used as the start of the array.
extern unsigned char const charset[127-32][6]

#define assert(x) do { while (!(x)) kdebug ("assertion failed " #x); } while (0)

enum types:
	LCD_EOF_CB = 32
	LCD_LOG

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

static unsigned physical_descriptor

struct Descriptor:
	unsigned next
	unsigned frame
	unsigned id
	unsigned cmd

static void reset ():
	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 ()

	LCD_DA0 = physical_descriptor
	lcd_set_ena ()
	lcd_enable_eof_intr ()

static void putchar (unsigned x, unsigned y, unsigned ch, unsigned fg = 0xffff, unsigned bg = 0x0000):
	if ch < 32 || ch > 126:
		ch = 127
	ch -= 32
	unsigned lookup[2] = { bg, fg }
	for unsigned k = 0; k < 6; ++k:
		for unsigned r = 0; r < 8; ++r:
			LCD_FRAMEBUFFER_BASE[(y * 8 + r) * 800 + x * 6 + k] = lookup[charset[ch][k] & (1 << r) ? 1 : 0]

static unsigned log_x = 1, log_y = 1
static void inc_logx ():
	if ++log_x >= 800 / 6:
		log_x = 1
		if ++log_y >= 480 / 8:
			log_y = 1

static void log_char (unsigned ch):
	switch ch:
		case '\n':
			while log_x < 800 / 6:
				putchar (log_x++, log_y, ' ')
			inc_logx ()
			break
		default:
			putchar (log_x, log_y, ch)
			inc_logx ()

static void log_str (char const *str):
	while *str:
		log_char (*str++)

static void log_num (Kernel::Num n):
	char const *encode = "0123456789abcdef"
	log_char ('[')
	for unsigned i = 0; i < 8; ++i:
		log_char (encode[(n.h >> (4 * (7 - i))) & 0xf])
	log_char (' ')
	for unsigned i = 0; i < 8; ++i:
		log_char (encode[(n.l >> (4 * (7 - i))) & 0xf])
	log_char (']')

static void log_msg ():
	log_str ("prot:")
	log_num (Kernel::recv.protected_data)
	log_str ("data:")
	for unsigned i = 0; i < 2; ++i:
		log_num (Kernel::recv.data[i])
	log_char ('\n')

Kernel::Num start ():
	map_lcd ()
	map_cpm ()

	Descriptor descriptor __attribute__ ((aligned (16)))
	unsigned pages = (frame_size + ~PAGE_MASK) >> PAGE_BITS
	unsigned physical = Kernel::my_memory.alloc_range (pages)
	assert (physical & PAGE_MASK && ~physical)
	for unsigned i = 0; i < pages; ++i:
		Kernel::Page p = Kernel::my_memory.create_page ()
		p.alloc_physical (physical + i * PAGE_SIZE, false, true)
		Kernel::my_memory.map (p, (unsigned)LCD_FRAMEBUFFER_BASE + i * PAGE_SIZE)
		Kernel::free_cap (p)
	for unsigned y = 0; y < 480; ++y:
		unsigned g = (y << 6) / 480
		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)
	Kernel::Page p = Kernel::my_memory.mapping (&descriptor)
	physical_descriptor = p.physical_address () + ((unsigned)&descriptor & ~PAGE_MASK)
	Kernel::free_cap (p)
	descriptor.next = physical_descriptor
	descriptor.frame = physical
	descriptor.id = 0xdeadbeef
	descriptor.cmd = LCD_CMD_EOFINT | ((frame_size / 4) << LCD_CMD_LEN_BIT)
	unsigned dptr = (unsigned)&descriptor
	__asm__ volatile ("lw $a0, %0\ncache 0x15, 0($a0)" :: "m"(dptr) : "memory", "a0")
	reset ()

	Kernel::Cap logcap = Kernel::my_receiver.create_capability (LCD_LOG)
	__asm__ volatile ("li $a0, 1\nlw $a1, %0\nbreak" :: "m"(logcap.code): "a0", "a1", "memory")

	Kernel::Cap set_eof_cb = Kernel::my_receiver.create_capability (LCD_EOF_CB)
	Kernel::my_parent.ocall (set_eof_cb, INIT_SET_LCD)

	unsigned slot = Kernel::alloc_slot ()
	Kernel::Cap eof_cb = Kernel::alloc_cap ()
	while true:
		Kernel::wait ()
		//log_msg ()
		switch Kernel::recv.protected_data.l:
			case IRQ_LCD:
				lcd_clr_eof ()
				eof_cb.invoke ()
				break
			case LCD_EOF_CB:
				Kernel::free_cap (eof_cb)
				eof_cb = Kernel::recv.arg
				Kernel::recv.arg = Kernel::alloc_cap ()
				Kernel::recv.reply.invoke ()
				Kernel::register_interrupt (IRQ_LCD)
				break
			case LCD_LOG:
				log_char (Kernel::recv.data[0].l)
				break
			default:
				log_char ('~')
				break