// SPDX-License-Identifier: GPL-2.0+
/*
 * 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
 */

#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)
{
	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)
{
	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)
{
	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");