ugfx/drivers/gdisp/ED060SC4/gdisp_lld.c

607 lines
12 KiB
C

/*
* This file is subject to the terms of the GFX License. If a copy of
* the license was not distributed with this file, you can obtain one at:
*
* http://ugfx.org/license.html
*/
/* Low-level E-ink panel driver routines for ED060SC4. */
#include "gfx.h"
#include "ed060sc4.h"
#if GFX_USE_GDISP
#include "gdisp/lld/emulation.c"
/* =================================
* Default configuration
* ================================= */
#ifndef GDISP_SCREEN_HEIGHT
# define GDISP_SCREEN_HEIGHT 600
#endif
#ifndef GDISP_SCREEN_WIDTH
# define GDISP_SCREEN_WIDTH 800
#endif
/* Number of pixels per byte */
#ifndef EINK_PPB
# define EINK_PPB 4
#endif
/* Delay for generating clock pulses.
* Unit is approximate clock cycles of the CPU (0 to 15).
* This should be atleast 50 ns.
*/
#ifndef EINK_CLOCKDELAY
# define EINK_CLOCKDELAY 0
#endif
/* Width of one framebuffer block.
* Must be divisible by EINK_PPB and evenly divide GDISP_SCREEN_WIDTH. */
#ifndef EINK_BLOCKWIDTH
# define EINK_BLOCKWIDTH 20
#endif
/* Height of one framebuffer block.
* Must evenly divide GDISP_SCREEN_WIDTH. */
#ifndef EINK_BLOCKHEIGHT
# define EINK_BLOCKHEIGHT 20
#endif
/* Number of block buffers to use for framebuffer emulation. */
#ifndef EINK_NUMBUFFERS
# define EINK_NUMBUFFERS 40
#endif
/* Do a "blinking" clear, i.e. clear to opposite polarity first.
* This reduces the image persistence. */
#ifndef EINK_BLINKCLEAR
# define EINK_BLINKCLEAR TRUE
#endif
/* Number of passes to use when clearing the display */
#ifndef EINK_CLEARCOUNT
# define EINK_CLEARCOUNT 10
#endif
/* Number of passes to use when writing to the display */
#ifndef EINK_WRITECOUNT
# define EINK_WRITECOUNT 4
#endif
/* ====================================
* Lower level driver functions
* ==================================== */
#include "gdisp_lld_board.h"
/** Delay between signal changes, to give time for IO pins to change state. */
static inline void clockdelay()
{
#if EINK_CLOCKDELAY & 1
asm("nop");
#endif
#if EINK_CLOCKDELAY & 2
asm("nop");
asm("nop");
#endif
#if EINK_CLOCKDELAY & 4
asm("nop");
asm("nop");
asm("nop");
asm("nop");
#endif
#if EINK_CLOCKDELAY & 8
asm("nop");
asm("nop");
asm("nop");
asm("nop");
asm("nop");
asm("nop");
asm("nop");
asm("nop");
#endif
}
/** Fast vertical clock pulse for gate driver, used during initializations */
static void vclock_quick()
{
setpin_ckv(TRUE);
eink_delay(1);
setpin_ckv(FALSE);
eink_delay(4);
}
/** Horizontal clock pulse for clocking data into source driver */
static void hclock()
{
clockdelay();
setpin_cl(TRUE);
clockdelay();
setpin_cl(FALSE);
}
/** Start a new vertical gate driver scan from top.
* Note: Does not clear any previous bits in the shift register,
* so you should always scan through the whole display before
* starting a new scan.
*/
static void vscan_start()
{
setpin_gmode(TRUE);
vclock_quick();
setpin_spv(FALSE);
vclock_quick();
setpin_spv(TRUE);
vclock_quick();
}
/** Waveform for strobing a row of data onto the display.
* Attempts to minimize the leaking of color to other rows by having
* a long idle period after a medium-length strobe period.
*/
static void vscan_write()
{
setpin_ckv(TRUE);
setpin_oe(TRUE);
eink_delay(5);
setpin_oe(FALSE);
setpin_ckv(FALSE);
eink_delay(200);
}
/** Waveform used when clearing the display. Strobes a row of data to the
* screen, but does not mind some of it leaking to other rows.
*/
static void vscan_bulkwrite()
{
setpin_ckv(TRUE);
eink_delay(20);
setpin_ckv(FALSE);
eink_delay(200);
}
/** Waveform for skipping a vertical row without writing anything.
* Attempts to minimize the amount of change in any row.
*/
static void vscan_skip()
{
setpin_ckv(TRUE);
eink_delay(1);
setpin_ckv(FALSE);
eink_delay(100);
}
/** Stop the vertical scan. The significance of this escapes me, but it seems
* necessary or the next vertical scan may be corrupted.
*/
static void vscan_stop()
{
setpin_gmode(FALSE);
vclock_quick();
vclock_quick();
vclock_quick();
vclock_quick();
vclock_quick();
}
/** Start updating the source driver data (from left to right). */
static void hscan_start()
{
/* Disable latching and output enable while we are modifying the row. */
setpin_le(FALSE);
setpin_oe(FALSE);
/* The start pulse should remain low for the duration of the row. */
setpin_sph(FALSE);
}
/** Write data to the horizontal row. */
static void hscan_write(const uint8_t *data, int count)
{
while (count--)
{
/* Set the next byte on the data pins */
setpins_data(*data++);
/* Give a clock pulse to the shift register */
hclock();
}
}
/** Finish and transfer the row to the source drivers.
* Does not set the output enable, so the drivers are not yet active. */
static void hscan_stop()
{
/* End the scan */
setpin_sph(TRUE);
hclock();
/* Latch the new data */
setpin_le(TRUE);
clockdelay();
setpin_le(FALSE);
}
/** Turn on the power to the E-Ink panel, observing proper power sequencing. */
static void power_on()
{
unsigned i;
/* First the digital power supply and signal levels. */
setpower_vdd(TRUE);
setpin_le(FALSE);
setpin_oe(FALSE);
setpin_cl(FALSE);
setpin_sph(TRUE);
setpins_data(0);
setpin_ckv(FALSE);
setpin_gmode(FALSE);
setpin_spv(TRUE);
/* Min. 100 microsecond delay after digital supply */
gfxSleepMicroseconds(100);
/* Then negative voltages and min. 1000 microsecond delay. */
setpower_vneg(TRUE);
gfxSleepMicroseconds(1000);
/* Finally the positive voltages. */
setpower_vpos(TRUE);
/* Clear the vscan shift register */
vscan_start();
for (i = 0; i < GDISP_SCREEN_HEIGHT; i++)
vclock_quick();
vscan_stop();
}
/** Turn off the power, observing proper power sequencing. */
static void power_off()
{
/* First the high voltages */
setpower_vpos(FALSE);
setpower_vneg(FALSE);
/* Wait for any capacitors to drain */
gfxSleepMilliseconds(100);
/* Then put all signals and digital supply to ground. */
setpin_le(FALSE);
setpin_oe(FALSE);
setpin_cl(FALSE);
setpin_sph(FALSE);
setpins_data(0);
setpin_ckv(FALSE);
setpin_gmode(FALSE);
setpin_spv(FALSE);
setpower_vdd(FALSE);
}
/* ====================================
* Framebuffer emulation layer
* ==================================== */
#if EINK_PPB == 4
#define PIXELMASK 3
#define PIXEL_WHITE 2
#define PIXEL_BLACK 1
#define BYTE_WHITE 0xAA
#define BYTE_BLACK 0x55
#else
#error Unsupported EINK_PPB value.
#endif
#if GDISP_SCREEN_HEIGHT % EINK_BLOCKHEIGHT != 0
#error GDISP_SCREEN_HEIGHT must be evenly divisible by EINK_BLOCKHEIGHT
#endif
#if GDISP_SCREEN_WIDTH % EINK_BLOCKWIDTH != 0
#error GDISP_SCREEN_WIDTH must be evenly divisible by EINK_BLOCKWIDTH
#endif
#if EINK_BLOCKWIDTH % EINK_PPB != 0
#error EINK_BLOCKWIDTH must be evenly divisible by EINK_PPB
#endif
#if EINK_NUMBUFFERS > 254
#error EINK_NUMBUFFERS must be at most 254.
#endif
#define BLOCKS_Y (GDISP_SCREEN_HEIGHT / EINK_BLOCKHEIGHT)
#define BLOCKS_X (GDISP_SCREEN_WIDTH / EINK_BLOCKWIDTH)
#define WIDTH_BYTES (EINK_BLOCKWIDTH / EINK_PPB)
/* Buffers that store the data for a small area of the display. */
typedef struct {
uint8_t data[EINK_BLOCKHEIGHT][WIDTH_BYTES];
} block_t;
static uint8_t g_next_block; /* Index of the next free block buffer. */
static block_t g_blocks[EINK_NUMBUFFERS];
/* Map that stores the buffers associated to each area of the display.
* Value of 0 means that the block is not allocated.
* Other values are the index in g_blocks + 1.
*/
static uint8_t g_blockmap[BLOCKS_Y][BLOCKS_X];
/** Check if the row contains any allocated blocks. */
static bool_t blocks_on_row(unsigned by)
{
unsigned bx;
for (bx = 0; bx < BLOCKS_X; bx++)
{
if (g_blockmap[by][bx] != 0)
{
return TRUE;
}
}
return FALSE;
}
/** Write out a block row. */
static void write_block_row(unsigned by)
{
unsigned bx, dy, dx;
for (dy = 0; dy < EINK_BLOCKHEIGHT; dy++)
{
hscan_start();
for (bx = 0; bx < BLOCKS_X; bx++)
{
if (g_blockmap[by][bx] == 0)
{
for (dx = 0; dx < WIDTH_BYTES; dx++)
{
const uint8_t dummy = 0;
hscan_write(&dummy, 1);
}
}
else
{
block_t *block = &g_blocks[g_blockmap[by][bx] - 1];
hscan_write(&block->data[dy][0], WIDTH_BYTES);
}
}
hscan_stop();
vscan_write();
}
}
/** Clear the block map, i.e. deallocate all blocks */
static void clear_block_map()
{
unsigned bx, by;
for (by = 0; by < BLOCKS_Y; by++)
{
for (bx = 0; bx < BLOCKS_X; bx++)
{
g_blockmap[by][bx] = 0;
}
}
g_next_block = 0;
}
/** Flush all the buffered rows to display. */
static void flush_buffers()
{
unsigned by, dy, i;
for (i = 0; i < EINK_WRITECOUNT; i++)
{
vscan_start();
for (by = 0; by < BLOCKS_Y; by++)
{
if (!blocks_on_row(by))
{
/* Skip the whole row of blocks. */
for (dy = 0; dy < EINK_BLOCKHEIGHT; dy++)
{
vscan_skip();
}
}
else
{
/* Write out the blocks. */
write_block_row(by);
}
}
vscan_stop();
}
clear_block_map();
}
/** Initialize a newly allocated block. */
static void zero_block(block_t *block)
{
unsigned dx, dy;
for (dy = 0; dy < EINK_BLOCKHEIGHT; dy++)
{
for (dx = 0; dx < WIDTH_BYTES; dx++)
{
block->data[dy][dx] = 0;
}
}
}
/** Allocate a buffer
* Automatically flushes if all buffers are full. */
static block_t *alloc_buffer(unsigned bx, unsigned by)
{
block_t *result;
if (g_blockmap[by][bx] == 0)
{
if (g_next_block >= EINK_NUMBUFFERS)
{
flush_buffers();
}
result = &g_blocks[g_next_block];
g_blockmap[by][bx] = g_next_block + 1;
g_next_block++;
zero_block(result);
return result;
}
else
{
result = &g_blocks[g_blockmap[by][bx] - 1];
return result;
}
}
/* ===============================
* Public functions
* =============================== */
bool_t gdisp_lld_init(void)
{
init_board();
/* Make sure that all the pins are in "off" state.
* Having any pin high could cause voltage leaking to the
* display, which in turn causes the image to leak slowly away.
*/
power_off();
clear_block_map();
/* Initialize the global GDISP structure */
GDISP.Width = GDISP_SCREEN_WIDTH;
GDISP.Height = GDISP_SCREEN_HEIGHT;
GDISP.Orientation = GDISP_ROTATE_0;
GDISP.Powermode = powerOff;
GDISP.Backlight = 0;
GDISP.Contrast = 0;
#if GDISP_NEED_VALIDATION || GDISP_NEED_CLIP
GDISP.clipx0 = 0;
GDISP.clipy0 = 0;
GDISP.clipx1 = GDISP.Width;
GDISP.clipy1 = GDISP.Height;
#endif
return TRUE;
}
void gdisp_lld_draw_pixel(coord_t x, coord_t y, color_t color)
{
block_t *block;
uint8_t byte;
unsigned bx, by, dx, dy;
uint8_t bitpos;
bx = x / EINK_BLOCKWIDTH;
by = y / EINK_BLOCKHEIGHT;
dx = x % EINK_BLOCKWIDTH;
dy = y % EINK_BLOCKHEIGHT;
if (bx < 0 || bx >= BLOCKS_X || by < 0 || by >= BLOCKS_Y)
return;
block = alloc_buffer(bx, by);
bitpos = (6 - 2 * (dx % EINK_PPB));
byte = block->data[dy][dx / EINK_PPB];
byte &= ~(PIXELMASK << bitpos);
if (color)
{
byte |= PIXEL_WHITE << bitpos;
}
else
{
byte |= PIXEL_BLACK << bitpos;
}
block->data[dy][dx / EINK_PPB] = byte;
}
#if !GDISP_NEED_CONTROL
#error You must enable GDISP_NEED_CONTROL for the E-Ink driver.
#endif
void gdisp_lld_control(unsigned what, void *value) {
gdisp_powermode_t newmode;
switch(what)
{
case GDISP_CONTROL_POWER:
newmode = (gdisp_powermode_t)value;
if (GDISP.Powermode == newmode)
return;
if (newmode == powerOn)
{
power_on();
}
else
{
flush_buffers();
power_off();
}
GDISP.Powermode = newmode;
break;
case GDISP_CONTROL_FLUSH:
flush_buffers();
break;
}
}
/* ===============================
* Accelerated routines
* =============================== */
#if GDISP_HARDWARE_CLEARS
static void subclear(color_t color)
{
unsigned x, y;
uint8_t byte;
hscan_start();
byte = color ? BYTE_WHITE : BYTE_BLACK;
for (x = 0; x < GDISP_SCREEN_WIDTH; x++)
{
hscan_write(&byte, 1);
}
hscan_stop();
setpin_oe(TRUE);
vscan_start();
for (y = 0; y < GDISP_SCREEN_HEIGHT; y++)
{
vscan_bulkwrite();
}
vscan_stop();
setpin_oe(FALSE);
}
void gdisp_lld_clear(color_t color)
{
unsigned i;
clear_block_map();
if (EINK_BLINKCLEAR)
{
subclear(!color);
gfxSleepMilliseconds(50);
}
for (i = 0; i < EINK_CLEARCOUNT; i++)
{
subclear(color);
gfxSleepMilliseconds(10);
}
}
#endif
#endif