#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)

#if defined (TRENDTAC)
static unsigned h = 800, v = 480, fps = 60, Bpp = 2
#elif defined (NANONOTE)
static unsigned h = 320, v = 240, fps = 70, Bpp = 4
#else
#error unknown board
#endif
#define frame_size (v * h * Bpp)

static unsigned physical_descriptor

/**/struct Descriptor {
	unsigned next;
	unsigned frame;
	unsigned id;
	unsigned cmd;
 } __attribute__ ((packed))

#if defined (NANONOTE)
#define SP_PORT 2
#define SPEN 21
#define SPDA 22
#define SPCK 23

static void udelay (unsigned num):
	for unsigned i = 0; i < num * (JZ_EXTAL / 1000000); ++i:
		// set 0 does nothing, but costs at least one clock pulse.
		gpio_set (SP_PORT, 0)

// Register names.  The registers are not named in the datasheet, and in some cases the name only describes a part of the bits in it.
// The registers with bit 6 set have bit 7 set instead, because of the transfer method.
enum spi_reg:
	AC		= 0x00
	DC		= 0x01
	BRIGHTNESS	= 0x03
	FORMAT		= 0x04
	BACKLIGHT1	= 0x05
	VBLANK		= 0x06
	HBLANK		= 0x07
	BACKLIGHT2	= 0x08
	SYNC		= 0x0b
	POLARITY	= 0x0c
	CONTRAST_B	= 0x0d
	SUB_CONTRAST_R	= 0x0e
	SUB_BRIGHTNESS_R= 0x0f
	SUB_CONTRAST_B	= 0x10
	SUB_BRIGHTNESS_B= 0x11
	TRIM		= 0x12
	COLOR		= 0x13
	GAMMA		= 0x16
	GAMMA1		= 0x17
	GAMMA2		= 0x18
	GAMMA3		= 0x19
	GAMMA4		= 0x1a
	INVERSION	= 0xa5
	HLEVEL		= 0xa6
	LLEVEL		= 0xa7
	FB		= 0xb1

static void write_reg (unsigned reg, unsigned val):
	gpio_clear (SP_PORT, 1 << SPEN)
	udelay (1)
	unsigned value = (reg << 8) | (val & 0xff)
	for unsigned i = 0; i < 16; ++i, value <<= 1:
		gpio_clear (SP_PORT, 1 << SPCK)
		if value & 0x8000:
			gpio_set (SP_PORT, 1 << SPDA)
		else:
			gpio_clear (SP_PORT, 1 << SPDA)
		udelay (4)
		gpio_set (SP_PORT, 1 << SPCK)
		udelay (1)
	gpio_set (SP_PORT, 1 << SPEN)
	udelay(4)
#endif

static void reset ():
	#if defined (TRENDTAC)
	// Note that the sync pulse is part of the pre-display region.
	// Vertical timings.
	unsigned vsync = 20, vpre = 20, vpost = 0
	// Horizontal timings.
	unsigned hsync = 80, hpre = 80, hpost = 0

	// One clock pulse per pixel.
	unsigned extra = 0
	// Bits per pixel.
	unsigned bpp = LCD_CTRL_BPP_16
	// Configuration.
	#define MODE_TFT_GEN 0
	#define VSYNC_N (1 << 8)
	unsigned cfg = MODE_TFT_GEN | VSYNC_N
	#elif defined (NANONOTE)
	// Note that the sync pulse is part of the pre-display region.
	// Vertical timings.
	unsigned vsync = 1, vpre = 21, vpost = 2
	// Horizontal timings.
	unsigned hsync = 1, hpre = 70, hpost = 686

	// 3 bytes per pixel, so for the display area 2 extra clocks are sent.
	unsigned extra = 2
	// Bits per pixel.
	unsigned bpp = LCD_CTRL_BPP_18_24
	// Configuration.
	unsigned cfg = LCD_CFG_MODE_SERIAL_TFT | LCD_CFG_HSP | LCD_CFG_VSP
	// Set up SPI pins.
	gpio_as_output(SP_PORT, (1 << SPEN) | (1 << SPCK) | (1 << SPDA))
	gpio_set (SP_PORT, (1 << SPEN) | (1 << SPCK))
	#else
	#error unknown board
	#endif

	// Note that the sync pulse is part of the pre-display region.
	unsigned vps = 0, vpe = vps + vsync, vds = vps + vpre, vde = vds + v, vt = vde + vpost
	unsigned hps = 0, hpe = hps + hsync, hds = hps + hpre, hde = hds + h, ht = hde + hpost

	LCD_CFG = cfg
	LCD_HSYNC = (hps << 16) | hpe
	LCD_VSYNC = (vps << 16) | vpe
	LCD_VAT = (ht << 16) | vt
	LCD_DAH = (hds << 16) | hde
	LCD_DAV = (vds << 16) | vde
	LCD_CTRL = (bpp << LCD_CTRL_BPP_BIT) | LCD_CTRL_BST_16

	cpm_stop_lcd ()

	unsigned pixclock = fps * (ht + extra * h) * vt

	#if defined (TRENDTAC)
	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
	#elif defined (NANONOTE)
	unsigned val = cpm_get_pllout2 () / pixclock - 1
	kdebug_num (val)
	kdebug ("\n")
	assert (val < 0x400)
	cpm_set_pixdiv (val);

	val = cpm_get_pllout () / (pixclock * 3)
	assert (val < 0x20)
	cpm_set_ldiv (val)
	// Update dividers.
	CPM_CPCCR |= CPM_CPCCR_CE
	#endif

	cpm_start_lcd ()
	LCD_DA0 = physical_descriptor
	lcd_set_ena ()
	//lcd_enable_eof_intr ()

	#ifdef NANONOTE
	// Reset registers.
	write_reg (BACKLIGHT1, 0)
	// Enable display.
	write_reg (BACKLIGHT1, 0x5f)
	#endif

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) * h + 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 >= h / 6:
		log_x = 1
		if ++log_y >= v / 8:
			log_y = 1

static void log_char (unsigned ch):
	switch ch:
		case '\n':
			while log_x < h / 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')

enum captype:
	LOG
	SET_EOF_CB

Kernel::Num start ():
	map_lcd ()
	map_cpm ()
	#ifdef NANONOTE
	map_gpio ()
	#endif

	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 < v; ++y:
		unsigned g = (y << 8) / v
		for unsigned x = 0; x < h; ++x:
			unsigned r = (x << 8) / h
			unsigned b = ((x + y) << 8) / (h + v)
			#if defined (TRENDTAC)
			LCD_FRAMEBUFFER_BASE[y * h + x] = ((r >> 3) << 11) | ((g >> 2) << 5) | (b >> 3)
			#elif defined (NANONOTE)
			LCD_FRAMEBUFFER_BASE[(y * h + x) * Bpp + 2] = r
			LCD_FRAMEBUFFER_BASE[(y * h + x) * Bpp + 1] = g
			LCD_FRAMEBUFFER_BASE[(y * h + x) * Bpp + 0] = b
			#else
			#error "Define your framebuffer format."
			#endif
	Kernel::Page p = Kernel::my_memory.mapping (&descriptor)
	unsigned paddr = p.physical_address ()
	physical_descriptor = paddr + ((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 (LOG)
	#if defined (TRENDTAC)
	__asm__ volatile ("li $a0, 1\nlw $a1, %0\nbreak" :: "m"(logcap.code): "a0", "a1", "memory")
	#endif

	Kernel::Cap eof_cb
	bool have_eof = false
	while true:
		Kernel::wait ()
		//log_msg ()
		switch Kernel::recv.protected_data.l:
			case IRQ_LCD:
				lcd_clr_eof ()
				eof_cb.invoke ()
				break
			case SET_EOF_CB:
				if have_eof:
					Kernel::free_cap (eof_cb)
				else:
					have_eof = true
				eof_cb = Kernel::get_arg ()
				Kernel::Cap reply = Kernel::get_reply ()
				Kernel::register_interrupt (IRQ_LCD)
				reply.invoke ()
				Kernel::free_cap (reply)
				break
			case LOG:
				log_char (Kernel::recv.data[0].l)
				break
			default:
				log_char ('~')
				break