- 根目录:
- drivers
- staging
- fbtft
- fb_agm1264k-fl.c
/*
* FB driver for Two KS0108 LCD controllers in AGM1264K-FL display
*
* Copyright (C) 2014 ololoshka2871
*
* 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 2 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.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include "fbtft.h"
/* Uncomment text line to use negative image on display */
/*#define NEGATIVE*/
#define WHITE 0xff
#define BLACK 0
#define DRVNAME "fb_agm1264k-fl"
#define WIDTH 64
#define HEIGHT 64
#define TOTALWIDTH (WIDTH * 2) /* because 2 x ks0108 in one display */
#define FPS 20
#define EPIN gpio.wr
#define RS gpio.dc
#define RW gpio.aux[2]
#define CS0 gpio.aux[0]
#define CS1 gpio.aux[1]
/* diffusing error (Floyd-Steinberg) */
#define DIFFUSING_MATRIX_WIDTH 2
#define DIFFUSING_MATRIX_HEIGHT 2
static const signed char
diffusing_matrix[DIFFUSING_MATRIX_WIDTH][DIFFUSING_MATRIX_HEIGHT] = {
{-1, 3},
{3, 2},
};
static const unsigned char gamma_correction_table[] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 6,
6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 11, 11, 11, 12, 12, 13,
13, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21,
22, 22, 23, 23, 24, 25, 25, 26, 26, 27, 28, 28, 29, 30, 30, 31, 32,
33, 33, 34, 35, 35, 36, 37, 38, 39, 39, 40, 41, 42, 43, 43, 44, 45,
46, 47, 48, 49, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 81,
82, 83, 84, 85, 87, 88, 89, 90, 91, 93, 94, 95, 97, 98, 99, 100, 102,
103, 105, 106, 107, 109, 110, 111, 113, 114, 116, 117, 119, 120, 121,
123, 124, 126, 127, 129, 130, 132, 133, 135, 137, 138, 140, 141, 143,
145, 146, 148, 149, 151, 153, 154, 156, 158, 159, 161, 163, 165, 166,
168, 170, 172, 173, 175, 177, 179, 181, 182, 184, 186, 188, 190, 192,
194, 196, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219,
221, 223, 225, 227, 229, 231, 234, 236, 238, 240, 242, 244, 246, 248,
251, 253, 255
};
static int init_display(struct fbtft_par *par)
{
u8 i;
par->fbtftops.reset(par);
for (i = 0; i < 2; ++i) {
write_reg(par, i, 0x3f); /* display on */
write_reg(par, i, 0x40); /* set x to 0 */
write_reg(par, i, 0xb0); /* set page to 0 */
write_reg(par, i, 0xc0); /* set start line to 0 */
}
return 0;
}
static void reset(struct fbtft_par *par)
{
if (par->gpio.reset == -1)
return;
dev_dbg(par->info->device, "%s()\n", __func__);
gpio_set_value(par->gpio.reset, 0);
udelay(20);
gpio_set_value(par->gpio.reset, 1);
mdelay(120);
}
/* Check if all necessary GPIOS defined */
static int verify_gpios(struct fbtft_par *par)
{
int i;
dev_dbg(par->info->device,
"%s()\n", __func__);
if (par->EPIN < 0) {
dev_err(par->info->device,
"Missing info about 'wr' (aka E) gpio. Aborting.\n");
return -EINVAL;
}
for (i = 0; i < 8; ++i) {
if (par->gpio.db[i] < 0) {
dev_err(par->info->device,
"Missing info about 'db[%i]' gpio. Aborting.\n",
i);
return -EINVAL;
}
}
if (par->CS0 < 0) {
dev_err(par->info->device,
"Missing info about 'cs0' gpio. Aborting.\n");
return -EINVAL;
}
if (par->CS1 < 0) {
dev_err(par->info->device,
"Missing info about 'cs1' gpio. Aborting.\n");
return -EINVAL;
}
if (par->RW < 0) {
dev_err(par->info->device,
"Missing info about 'rw' gpio. Aborting.\n");
return -EINVAL;
}
return 0;
}
static unsigned long
request_gpios_match(struct fbtft_par *par, const struct fbtft_gpio *gpio)
{
dev_dbg(par->info->device,
"%s('%s')\n", __func__, gpio->name);
if (strcasecmp(gpio->name, "wr") == 0) {
/* left ks0108 E pin */
par->EPIN = gpio->gpio;
return GPIOF_OUT_INIT_LOW;
} else if (strcasecmp(gpio->name, "cs0") == 0) {
/* left ks0108 controller pin */
par->CS0 = gpio->gpio;
return GPIOF_OUT_INIT_HIGH;
} else if (strcasecmp(gpio->name, "cs1") == 0) {
/* right ks0108 controller pin */
par->CS1 = gpio->gpio;
return GPIOF_OUT_INIT_HIGH;
}
/* if write (rw = 0) e(1->0) perform write */
/* if read (rw = 1) e(0->1) set data on D0-7*/
else if (strcasecmp(gpio->name, "rw") == 0) {
par->RW = gpio->gpio;
return GPIOF_OUT_INIT_LOW;
}
return FBTFT_GPIO_NO_MATCH;
}
/* This function oses to enter commands
* first byte - destination controller 0 or 1
* following - commands
*/
static void write_reg8_bus8(struct fbtft_par *par, int len, ...)
{
va_list args;
int i, ret;
u8 *buf = par->buf;
if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {
va_start(args, len);
for (i = 0; i < len; i++)
buf[i] = (u8)va_arg(args, unsigned int);
va_end(args);
fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par,
par->info->device, u8, buf, len, "%s: ", __func__);
}
va_start(args, len);
*buf = (u8)va_arg(args, unsigned int);
if (*buf > 1) {
va_end(args);
dev_err(par->info->device,
"Incorrect chip select request (%d)\n", *buf);
return;
}
/* select chip */
if (*buf) {
/* cs1 */
gpio_set_value(par->CS0, 1);
gpio_set_value(par->CS1, 0);
} else {
/* cs0 */
gpio_set_value(par->CS0, 0);
gpio_set_value(par->CS1, 1);
}
gpio_set_value(par->RS, 0); /* RS->0 (command mode) */
len--;
if (len) {
i = len;
while (i--)
*buf++ = (u8)va_arg(args, unsigned int);
ret = par->fbtftops.write(par, par->buf, len * (sizeof(u8)));
if (ret < 0) {
va_end(args);
dev_err(par->info->device,
"write() failed and returned %d\n", ret);
return;
}
}
va_end(args);
}
static struct
{
int xs, ys_page, xe, ye_page;
} addr_win;
/* save display writing zone */
static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
{
addr_win.xs = xs;
addr_win.ys_page = ys / 8;
addr_win.xe = xe;
addr_win.ye_page = ye / 8;
}
static void
construct_line_bitmap(struct fbtft_par *par, u8 *dest, signed short *src,
int xs, int xe, int y)
{
int x, i;
for (x = xs; x < xe; ++x) {
u8 res = 0;
for (i = 0; i < 8; i++)
if (src[(y * 8 + i) * par->info->var.xres + x])
res |= 1 << i;
#ifdef NEGATIVE
*dest++ = res;
#else
*dest++ = ~res;
#endif
}
}
static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
{
u16 *vmem16 = (u16 *)par->info->screen_buffer;
u8 *buf = par->txbuf.buf;
int x, y;
int ret = 0;
/* buffer to convert RGB565 -> grayscale16 -> Dithered image 1bpp */
signed short *convert_buf = kmalloc(par->info->var.xres *
par->info->var.yres * sizeof(signed short), GFP_NOIO);
if (!convert_buf)
return -ENOMEM;
/* converting to grayscale16 */
for (x = 0; x < par->info->var.xres; ++x)
for (y = 0; y < par->info->var.yres; ++y) {
u16 pixel = vmem16[y * par->info->var.xres + x];
u16 b = pixel & 0x1f;
u16 g = (pixel & (0x3f << 5)) >> 5;
u16 r = (pixel & (0x1f << (5 + 6))) >> (5 + 6);
pixel = (299 * r + 587 * g + 114 * b) / 200;
if (pixel > 255)
pixel = 255;
/* gamma-correction by table */
convert_buf[y * par->info->var.xres + x] =
(signed short)gamma_correction_table[pixel];
}
/* Image Dithering */
for (x = 0; x < par->info->var.xres; ++x)
for (y = 0; y < par->info->var.yres; ++y) {
signed short pixel =
convert_buf[y * par->info->var.xres + x];
signed short error_b = pixel - BLACK;
signed short error_w = pixel - WHITE;
signed short error;
u16 i, j;
/* what color close? */
if (abs(error_b) >= abs(error_w)) {
/* white */
error = error_w;
pixel = 0xff;
} else {
/* black */
error = error_b;
pixel = 0;
}
error /= 8;
/* diffusion matrix row */
for (i = 0; i < DIFFUSING_MATRIX_WIDTH; ++i)
/* diffusion matrix column */
for (j = 0; j < DIFFUSING_MATRIX_HEIGHT; ++j) {
signed short *write_pos;
signed char coeff;
/* skip pixels out of zone */
if (x + i < 0 ||
x + i >= par->info->var.xres
|| y + j >= par->info->var.yres)
continue;
write_pos = &convert_buf[
(y + j) * par->info->var.xres +
x + i];
coeff = diffusing_matrix[i][j];
if (coeff == -1)
/* pixel itself */
*write_pos = pixel;
else {
signed short p = *write_pos +
error * coeff;
if (p > WHITE)
p = WHITE;
if (p < BLACK)
p = BLACK;
*write_pos = p;
}
}
}
/* 1 string = 2 pages */
for (y = addr_win.ys_page; y <= addr_win.ye_page; ++y) {
/* left half of display */
if (addr_win.xs < par->info->var.xres / 2) {
construct_line_bitmap(par, buf, convert_buf,
addr_win.xs, par->info->var.xres / 2, y);
len = par->info->var.xres / 2 - addr_win.xs;
/* select left side (sc0)
* set addr
*/
write_reg(par, 0x00, (1 << 6) | (u8)addr_win.xs);
write_reg(par, 0x00, (0x17 << 3) | (u8)y);
/* write bitmap */
gpio_set_value(par->RS, 1); /* RS->1 (data mode) */
ret = par->fbtftops.write(par, buf, len);
if (ret < 0)
dev_err(par->info->device,
"write failed and returned: %d\n",
ret);
}
/* right half of display */
if (addr_win.xe >= par->info->var.xres / 2) {
construct_line_bitmap(par, buf,
convert_buf, par->info->var.xres / 2,
addr_win.xe + 1, y);
len = addr_win.xe + 1 - par->info->var.xres / 2;
/* select right side (sc1)
* set addr
*/
write_reg(par, 0x01, 1 << 6);
write_reg(par, 0x01, (0x17 << 3) | (u8)y);
/* write bitmap */
gpio_set_value(par->RS, 1); /* RS->1 (data mode) */
par->fbtftops.write(par, buf, len);
if (ret < 0)
dev_err(par->info->device,
"write failed and returned: %d\n",
ret);
}
}
kfree(convert_buf);
gpio_set_value(par->CS0, 1);
gpio_set_value(par->CS1, 1);
return ret;
}
static int write(struct fbtft_par *par, void *buf, size_t len)
{
fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
"%s(len=%d): ", __func__, len);
gpio_set_value(par->RW, 0); /* set write mode */
while (len--) {
u8 i, data;
data = *(u8 *) buf++;
/* set data bus */
for (i = 0; i < 8; ++i)
gpio_set_value(par->gpio.db[i], data & (1 << i));
/* set E */
gpio_set_value(par->EPIN, 1);
udelay(5);
/* unset E - write */
gpio_set_value(par->EPIN, 0);
udelay(1);
}
return 0;
}
static struct fbtft_display display = {
.regwidth = 8,
.width = TOTALWIDTH,
.height = HEIGHT,
.fps = FPS,
.fbtftops = {
.init_display = init_display,
.set_addr_win = set_addr_win,
.verify_gpios = verify_gpios,
.request_gpios_match = request_gpios_match,
.reset = reset,
.write = write,
.write_register = write_reg8_bus8,
.write_vmem = write_vmem,
},
};
FBTFT_REGISTER_DRIVER(DRVNAME, "displaytronic,fb_agm1264k-fl", &display);
MODULE_ALIAS("platform:" DRVNAME);
MODULE_DESCRIPTION("Two KS0108 LCD controllers in AGM1264K-FL display");
MODULE_AUTHOR("ololoshka2871");
MODULE_LICENSE("GPL");