fb_upd161704.c

/*
 * FB driver for the uPD161704 LCD Controller
 *
 * Copyright (C) 2014 Seong-Woo Kim
 *
 * Based on fb_ili9325.c by Noralf Tronnes
 * Based on ili9325.c by Jeroen Domburg
 * Init code from UTFT library by Henning Karlsen
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/gpio.h>
#include <linux/delay.h>

#include "fbtft.h"

#define DRVNAME		"fb_upd161704"
#define WIDTH		240
#define HEIGHT		320
#define BPP		16

static int init_display(struct fbtft_par *par)
{
	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);

	par->fbtftops.reset(par);

	if (par->gpio.cs != -1)
		gpio_set_value(par->gpio.cs, 0);  /* Activate chip */

	/* Initialization sequence from Lib_UTFT */

	/* register reset */
	write_reg(par, 0x0003,0x0001);	/* Soft reset */

	/* oscillator start */
	write_reg(par, 0x003A,0x0001);	/*Oscillator 0: stop, 1: operation */
	udelay(100);

	/* y-setting */
	write_reg(par, 0x0024,0x007B);	/* amplitude setting */
	udelay(10);
	write_reg(par, 0x0025,0x003B);	/* amplitude setting */
	write_reg(par, 0x0026,0x0034);	/* amplitude setting */
	udelay(10);
	write_reg(par, 0x0027,0x0004);	/* amplitude setting */
	write_reg(par, 0x0052,0x0025);	/* circuit setting 1 */
	udelay(10);
	write_reg(par, 0x0053,0x0033);	/* circuit setting 2 */
	write_reg(par, 0x0061,0x001C);	/* adjustment V10 positive polarity */
	udelay(10);
	write_reg(par, 0x0062,0x002C);	/* adjustment V9 negative polarity */
	write_reg(par, 0x0063,0x0022);	/* adjustment V34 positive polarity */
	udelay(10);
	write_reg(par, 0x0064,0x0027);	/* adjustment V31 negative polarity */
	udelay(10);
	write_reg(par, 0x0065,0x0014);	/* adjustment V61 negative polarity */
	udelay(10);
	write_reg(par, 0x0066,0x0010);	/* adjustment V61 negative polarity */
	
	/* Basical clock for 1 line (BASECOUNT[7:0]) number specified */
	write_reg(par, 0x002E,0x002D);
	
	/* Power supply setting */
	write_reg(par, 0x0019,0x0000);	/* DC/DC output setting */
	udelay(200);
	write_reg(par, 0x001A,0x1000);	/* DC/DC frequency setting */
	write_reg(par, 0x001B,0x0023);	/* DC/DC rising setting */
	write_reg(par, 0x001C,0x0C01);	/* Regulator voltage setting */
	write_reg(par, 0x001D,0x0000);	/* Regulator current setting */
	write_reg(par, 0x001E,0x0009);	/* VCOM output setting */
	write_reg(par, 0x001F,0x0035);	/* VCOM amplitude setting */
	write_reg(par, 0x0020,0x0015);	/* VCOMM cencter setting */
	write_reg(par, 0x0018,0x1E7B);	/* DC/DC operation setting */

	/* windows setting */
	write_reg(par, 0x0008,0x0000);	/* Minimum X address */
	write_reg(par, 0x0009,0x00EF);	/* Maximum X address */
	write_reg(par, 0x000a,0x0000);	/* Minimum Y address */
	write_reg(par, 0x000b,0x013F);	/* Maximum Y address */

	/* LCD display area setting */
	write_reg(par, 0x0029,0x0000);	/* [LCDSIZE]  X MIN. size set */
	write_reg(par, 0x002A,0x0000);	/* [LCDSIZE]  Y MIN. size set */
	write_reg(par, 0x002B,0x00EF);	/* [LCDSIZE]  X MAX. size set */
	write_reg(par, 0x002C,0x013F);	/* [LCDSIZE]  Y MAX. size set */

	/* Gate scan setting */
	write_reg(par, 0x0032,0x0002);
	
	/* n line inversion line number */
	write_reg(par, 0x0033,0x0000);

	/* Line inversion/frame inversion/interlace setting */
	write_reg(par, 0x0037,0x0000);
	
	/* Gate scan operation setting register */
	write_reg(par, 0x003B,0x0001);
	
	/* Color mode */
	/*GS = 0: 260-k color (64 gray scale), GS = 1: 8 color (2 gray scale) */
	write_reg(par, 0x0004,0x0000);

	/* RAM control register */
	write_reg(par, 0x0005,0x0000);	/*Window access 00:Normal, 10:Window */

	/* Display setting register 2 */
	write_reg(par, 0x0001,0x0000);

	/* display setting */
	write_reg(par, 0x0000,0x0000);	/* display on */

	return 0;
}

static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
{
	fbtft_par_dbg(DEBUG_SET_ADDR_WIN, par,
		"%s(xs=%d, ys=%d, xe=%d, ye=%d)\n", __func__, xs, ys, xe, ye);
	switch (par->info->var.rotate) {
	/* R20h = Horizontal GRAM Start Address */
	/* R21h = Vertical GRAM Start Address */
	case 0:
		write_reg(par, 0x0006, xs);
		write_reg(par, 0x0007, ys);
		break;
	case 180:
		write_reg(par, 0x0006, WIDTH - 1 - xs);
		write_reg(par, 0x0007, HEIGHT - 1 - ys);
		break;
	case 270:
		write_reg(par, 0x0006, WIDTH - 1 - ys);
		write_reg(par, 0x0007, xs);
		break;
	case 90:
		write_reg(par, 0x0006, ys);
		write_reg(par, 0x0007, HEIGHT - 1 - xs);
		break;
	}

	write_reg(par, 0x0e); /* Write Data to GRAM */
}

static int set_var(struct fbtft_par *par)
{
	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);

	switch (par->info->var.rotate) {
	/* AM: GRAM update direction */
	case 0:
		write_reg(par, 0x01, 0x0000);
		write_reg(par, 0x05, 0x0000);
		break;
	case 180:
		write_reg(par, 0x01, 0x00C0);
		write_reg(par, 0x05, 0x0000);
		break;
	case 270:
		write_reg(par, 0x01, 0x0080);
		write_reg(par, 0x05, 0x0001);
		break;
	case 90:
		write_reg(par, 0x01, 0x0040);
		write_reg(par, 0x05, 0x0001);
		break;
	}

	return 0;
}

static struct fbtft_display display = {
	.regwidth = 16,
	.width = WIDTH,
	.height = HEIGHT,
	.fbtftops = {
		.init_display = init_display,
		.set_addr_win = set_addr_win,
		.set_var = set_var,
	},
};
FBTFT_REGISTER_DRIVER(DRVNAME, "nec,upd161704", &display);

MODULE_ALIAS("spi:" DRVNAME);
MODULE_ALIAS("platform:" DRVNAME);
MODULE_ALIAS("spi:upd161704");
MODULE_ALIAS("platform:upd161704");

MODULE_DESCRIPTION("FB driver for the uPD161704 LCD Controller");
MODULE_AUTHOR("Seong-Woo Kim");
MODULE_LICENSE("GPL");