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// SPDX-License-Identifier: GPL-2.0+
/*
* FB driver for the Watterott LCD Controller
*
* Copyright (C) 2013 Noralf Tronnes
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include "fbtft.h"
#define DRVNAME "fb_watterott"
#define WIDTH 320
#define HEIGHT 240
#define FPS 5
#define TXBUFLEN 1024
#define DEFAULT_BRIGHTNESS 50
#define CMD_VERSION 0x01
#define CMD_LCD_LED 0x10
#define CMD_LCD_RESET 0x11
#define CMD_LCD_ORIENTATION 0x20
#define CMD_LCD_DRAWIMAGE 0x27
#define COLOR_RGB323 8
#define COLOR_RGB332 9
#define COLOR_RGB233 10
#define COLOR_RGB565 16
static short mode = 565;
module_param(mode, short, 0000);
MODULE_PARM_DESC(mode, "RGB color transfer mode: 332, 565 (default)");
static void write_reg8_bus8(struct fbtft_par *par, int len, ...)
{
va_list args;
int i, ret;
u8 *buf = par->buf;
va_start(args, len);
for (i = 0; i < len; i++)
*buf++ = (u8)va_arg(args, unsigned int);
va_end(args);
fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par,
par->info->device, u8, par->buf,
len, "%s: ", __func__);
ret = par->fbtftops.write(par, par->buf, len);
if (ret < 0) {
dev_err(par->info->device,
"write() failed and returned %d\n", ret);
return;
}
}
static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
{
unsigned int start_line, end_line;
u16 *vmem16 = (u16 *)(par->info->screen_buffer + offset);
__be16 *pos = par->txbuf.buf + 1;
__be16 *buf16 = par->txbuf.buf + 10;
int i, j;
int ret = 0;
start_line = offset / par->info->fix.line_length;
end_line = start_line + (len / par->info->fix.line_length) - 1;
/* Set command header. pos: x, y, w, h */
((u8 *)par->txbuf.buf)[0] = CMD_LCD_DRAWIMAGE;
pos[0] = 0;
pos[2] = cpu_to_be16(par->info->var.xres);
pos[3] = cpu_to_be16(1);
((u8 *)par->txbuf.buf)[9] = COLOR_RGB565;
for (i = start_line; i <= end_line; i++) {
pos[1] = cpu_to_be16(i);
for (j = 0; j < par->info->var.xres; j++)
buf16[j] = cpu_to_be16(*vmem16++);
ret = par->fbtftops.write(par,
par->txbuf.buf, 10 + par->info->fix.line_length);
if (ret < 0)
return ret;
udelay(300);
}
return 0;
}
static inline int rgb565_to_rgb332(u16 c)
{
return ((c & 0xE000) >> 8) | ((c & 000700) >> 6) | ((c & 0x0018) >> 3);
}
static int write_vmem_8bit(struct fbtft_par *par, size_t offset, size_t len)
{
unsigned int start_line, end_line;
u16 *vmem16 = (u16 *)(par->info->screen_buffer + offset);
__be16 *pos = par->txbuf.buf + 1;
u8 *buf8 = par->txbuf.buf + 10;
int i, j;
int ret = 0;
start_line = offset / par->info->fix.line_length;
end_line = start_line + (len / par->info->fix.line_length) - 1;
/* Set command header. pos: x, y, w, h */
((u8 *)par->txbuf.buf)[0] = CMD_LCD_DRAWIMAGE;
pos[0] = 0;
pos[2] = cpu_to_be16(par->info->var.xres);
pos[3] = cpu_to_be16(1);
((u8 *)par->txbuf.buf)[9] = COLOR_RGB332;
for (i = start_line; i <= end_line; i++) {
pos[1] = cpu_to_be16(i);
for (j = 0; j < par->info->var.xres; j++) {
buf8[j] = rgb565_to_rgb332(*vmem16);
vmem16++;
}
ret = par->fbtftops.write(par,
par->txbuf.buf, 10 + par->info->var.xres);
if (ret < 0)
return ret;
udelay(700);
}
return 0;
}
static unsigned int firmware_version(struct fbtft_par *par)
{
u8 rxbuf[4] = {0, };
write_reg(par, CMD_VERSION);
par->fbtftops.read(par, rxbuf, 4);
if (rxbuf[1] != '.')
return 0;
return (rxbuf[0] - '0') << 8 | (rxbuf[2] - '0') << 4 | (rxbuf[3] - '0');
}
static int init_display(struct fbtft_par *par)
{
int ret;
unsigned int version;
u8 save_mode;
/* enable SPI interface by having CS and MOSI low during reset */
save_mode = par->spi->mode;
/*
* Set CS active inverse polarity: just setting SPI_CS_HIGH does not
* work with GPIO based chip selects that are logically active high
* but inverted inside the GPIO library, so enforce inverted
* semantics.
*/
par->spi->mode ^= SPI_CS_HIGH;
ret = spi_setup(par->spi);
if (ret) {
dev_err(par->info->device,
"Could not set inverse CS polarity\n");
return ret;
}
write_reg(par, 0x00); /* make sure mode is set */
mdelay(50);
par->fbtftops.reset(par);
mdelay(1000);
par->spi->mode = save_mode;
ret = spi_setup(par->spi);
if (ret) {
dev_err(par->info->device, "Could not restore SPI mode\n");
return ret;
}
write_reg(par, 0x00);
version = firmware_version(par);
fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "Firmware version: %x.%02x\n",
version >> 8, version & 0xFF);
if (mode == 332)
par->fbtftops.write_vmem = write_vmem_8bit;
return 0;
}
static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
{
/* not used on this controller */
}
static int set_var(struct fbtft_par *par)
{
u8 rotate;
/* this controller rotates clock wise */
switch (par->info->var.rotate) {
case 90:
rotate = 27;
break;
case 180:
rotate = 18;
break;
case 270:
rotate = 9;
break;
default:
rotate = 0;
}
write_reg(par, CMD_LCD_ORIENTATION, rotate);
return 0;
}
static int verify_gpios(struct fbtft_par *par)
{
if (!par->gpio.reset) {
dev_err(par->info->device, "Missing 'reset' gpio. Aborting.\n");
return -EINVAL;
}
return 0;
}
#ifdef CONFIG_FB_BACKLIGHT
static int backlight_chip_update_status(struct backlight_device *bd)
{
struct fbtft_par *par = bl_get_data(bd);
int brightness = bd->props.brightness;
fbtft_par_dbg(DEBUG_BACKLIGHT, par,
"%s: brightness=%d, power=%d, fb_blank=%d\n", __func__,
bd->props.brightness, bd->props.power,
bd->props.fb_blank);
if (bd->props.power != FB_BLANK_UNBLANK)
brightness = 0;
if (bd->props.fb_blank != FB_BLANK_UNBLANK)
brightness = 0;
write_reg(par, CMD_LCD_LED, brightness);
return 0;
}
static const struct backlight_ops bl_ops = {
.update_status = backlight_chip_update_status,
};
static void register_chip_backlight(struct fbtft_par *par)
{
struct backlight_device *bd;
struct backlight_properties bl_props = { 0, };
bl_props.type = BACKLIGHT_RAW;
bl_props.power = FB_BLANK_POWERDOWN;
bl_props.max_brightness = 100;
bl_props.brightness = DEFAULT_BRIGHTNESS;
bd = backlight_device_register(dev_driver_string(par->info->device),
par->info->device, par, &bl_ops,
&bl_props);
if (IS_ERR(bd)) {
dev_err(par->info->device,
"cannot register backlight device (%ld)\n",
PTR_ERR(bd));
return;
}
par->info->bl_dev = bd;
if (!par->fbtftops.unregister_backlight)
par->fbtftops.unregister_backlight = fbtft_unregister_backlight;
}
#else
#define register_chip_backlight NULL
#endif
static struct fbtft_display display = {
.regwidth = 8,
.buswidth = 8,
.width = WIDTH,
.height = HEIGHT,
.fps = FPS,
.txbuflen = TXBUFLEN,
.fbtftops = {
.write_register = write_reg8_bus8,
.write_vmem = write_vmem,
.init_display = init_display,
.set_addr_win = set_addr_win,
.set_var = set_var,
.verify_gpios = verify_gpios,
.register_backlight = register_chip_backlight,
},
};
FBTFT_REGISTER_DRIVER(DRVNAME, "watterott,openlcd", &display);
MODULE_ALIAS("spi:" DRVNAME);
MODULE_DESCRIPTION("FB driver for the Watterott LCD Controller");
MODULE_AUTHOR("Noralf Tronnes");
MODULE_LICENSE("GPL");