drivers/staging/fbtft/fb_seps525.c

// SPDX-License-Identifier: GPL-2.0
/*
 * FB driver for the NHD-1.69-160128UGC3 (Newhaven Display International, Inc.)
 * using the SEPS525 (Syncoam) LCD Controller
 *
 * Copyright (C) 2016 Analog Devices Inc.
 *
 * 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 "fbtft.h"

#define DRVNAME		"fb_seps525"
#define WIDTH		160
#define HEIGHT		128

#define SEPS525_INDEX 0x00
#define SEPS525_STATUS_RD 0x01
#define SEPS525_OSC_CTL 0x02
#define SEPS525_IREF 0x80
#define SEPS525_CLOCK_DIV 0x03
#define SEPS525_REDUCE_CURRENT 0x04
#define SEPS525_SOFT_RST 0x05
#define SEPS525_DISP_ONOFF 0x06
#define SEPS525_PRECHARGE_TIME_R 0x08
#define SEPS525_PRECHARGE_TIME_G 0x09
#define SEPS525_PRECHARGE_TIME_B 0x0A
#define SEPS525_PRECHARGE_CURRENT_R 0x0B
#define SEPS525_PRECHARGE_CURRENT_G 0x0C
#define SEPS525_PRECHARGE_CURRENT_B 0x0D
#define SEPS525_DRIVING_CURRENT_R 0x10
#define SEPS525_DRIVING_CURRENT_G 0x11
#define SEPS525_DRIVING_CURRENT_B 0x12
#define SEPS525_DISPLAYMODE_SET 0x13
#define SEPS525_RGBIF 0x14
#define SEPS525_RGB_POL 0x15
#define SEPS525_MEMORY_WRITEMODE 0x16
#define SEPS525_MX1_ADDR 0x17
#define SEPS525_MX2_ADDR 0x18
#define SEPS525_MY1_ADDR 0x19
#define SEPS525_MY2_ADDR 0x1A
#define SEPS525_MEMORY_ACCESS_POINTER_X 0x20
#define SEPS525_MEMORY_ACCESS_POINTER_Y 0x21
#define SEPS525_DDRAM_DATA_ACCESS_PORT 0x22
#define SEPS525_GRAY_SCALE_TABLE_INDEX 0x50
#define SEPS525_GRAY_SCALE_TABLE_DATA 0x51
#define SEPS525_DUTY 0x28
#define SEPS525_DSL 0x29
#define SEPS525_D1_DDRAM_FAC 0x2E
#define SEPS525_D1_DDRAM_FAR 0x2F
#define SEPS525_D2_DDRAM_SAC 0x31
#define SEPS525_D2_DDRAM_SAR 0x32
#define SEPS525_SCR1_FX1 0x33
#define SEPS525_SCR1_FX2 0x34
#define SEPS525_SCR1_FY1 0x35
#define SEPS525_SCR1_FY2 0x36
#define SEPS525_SCR2_SX1 0x37
#define SEPS525_SCR2_SX2 0x38
#define SEPS525_SCR2_SY1 0x39
#define SEPS525_SCR2_SY2 0x3A
#define SEPS525_SCREEN_SAVER_CONTEROL 0x3B
#define SEPS525_SS_SLEEP_TIMER 0x3C
#define SEPS525_SCREEN_SAVER_MODE 0x3D
#define SEPS525_SS_SCR1_FU 0x3E
#define SEPS525_SS_SCR1_MXY 0x3F
#define SEPS525_SS_SCR2_FU 0x40
#define SEPS525_SS_SCR2_MXY 0x41
#define SEPS525_MOVING_DIRECTION 0x42
#define SEPS525_SS_SCR2_SX1 0x47
#define SEPS525_SS_SCR2_SX2 0x48
#define SEPS525_SS_SCR2_SY1 0x49
#define SEPS525_SS_SCR2_SY2 0x4A

/* SEPS525_DISPLAYMODE_SET */
#define MODE_SWAP_BGR	BIT(7)
#define MODE_SM		BIT(6)
#define MODE_RD		BIT(5)
#define MODE_CD		BIT(4)

#define seps525_use_window	0 /* FBTFT doesn't really use it today */

/* Init sequence taken from: Arduino Library for the Adafruit 2.2" display */
static int init_display(struct fbtft_par *par)
{
	par->fbtftops.reset(par);

	usleep_range(1000, 5000);

	/* Disable Oscillator Power Down */
	write_reg(par, SEPS525_REDUCE_CURRENT, 0x03);
	usleep_range(1000, 5000);
	/* Set Normal Driving Current */
	write_reg(par, SEPS525_REDUCE_CURRENT, 0x00);
	usleep_range(1000, 5000);

	write_reg(par, SEPS525_SCREEN_SAVER_CONTEROL, 0x00);
	/* Set EXPORT1 Pin at Internal Clock */
	write_reg(par, SEPS525_OSC_CTL, 0x01);
	/* Set Clock as 120 Frames/Sec */
	write_reg(par, SEPS525_CLOCK_DIV, 0x90);
	/* Set Reference Voltage Controlled by External Resister */
	write_reg(par, SEPS525_IREF, 0x01);

	/* precharge time R G B */
	write_reg(par, SEPS525_PRECHARGE_TIME_R, 0x04);
	write_reg(par, SEPS525_PRECHARGE_TIME_G, 0x05);
	write_reg(par, SEPS525_PRECHARGE_TIME_B, 0x05);

	/* precharge current R G B (uA) */
	write_reg(par, SEPS525_PRECHARGE_CURRENT_R, 0x9D);
	write_reg(par, SEPS525_PRECHARGE_CURRENT_G, 0x8C);
	write_reg(par, SEPS525_PRECHARGE_CURRENT_B, 0x57);

	/* driving current R G B (uA) */
	write_reg(par, SEPS525_DRIVING_CURRENT_R, 0x56);
	write_reg(par, SEPS525_DRIVING_CURRENT_G, 0x4D);
	write_reg(par, SEPS525_DRIVING_CURRENT_B, 0x46);
	/* Set Color Sequence */
	write_reg(par, SEPS525_DISPLAYMODE_SET, 0xA0);
	write_reg(par, SEPS525_RGBIF, 0x01); /* Set MCU Interface Mode */
	/* Set Memory Write Mode */
	write_reg(par, SEPS525_MEMORY_WRITEMODE, 0x66);
	write_reg(par, SEPS525_DUTY, 0x7F); /* 1/128 Duty (0x0F~0x7F) */
	/* Set Mapping RAM Display Start Line (0x00~0x7F) */
	write_reg(par, SEPS525_DSL, 0x00);
	write_reg(par, SEPS525_DISP_ONOFF, 0x01); /* Display On (0x00/0x01) */
	/* Set All Internal Register Value as Normal Mode */
	write_reg(par, SEPS525_SOFT_RST, 0x00);
	/* Set RGB Interface Polarity as Active Low */
	write_reg(par, SEPS525_RGB_POL, 0x00);

	write_reg(par, SEPS525_DDRAM_DATA_ACCESS_PORT);

	return 0;
}

static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
{
	if (seps525_use_window) {
		/* Set Window Xs,Ys Xe,Ye*/
		write_reg(par, SEPS525_MX1_ADDR, xs);
		write_reg(par, SEPS525_MX2_ADDR, xe);
		write_reg(par, SEPS525_MY1_ADDR, ys);
		write_reg(par, SEPS525_MY2_ADDR, ye);
	}
	/* start position X,Y */
	write_reg(par, SEPS525_MEMORY_ACCESS_POINTER_X, xs);
	write_reg(par, SEPS525_MEMORY_ACCESS_POINTER_Y, ys);

	write_reg(par, SEPS525_DDRAM_DATA_ACCESS_PORT);
}

static int set_var(struct fbtft_par *par)
{
	u8 val;

	switch (par->info->var.rotate) {
	case 0:
		val = 0;
		break;
	case 180:
		val = MODE_RD | MODE_CD;
		break;
	case 90:
	case 270:

	default:
		return -EINVAL;
	}
	/* Memory Access Control  */
	write_reg(par, SEPS525_DISPLAYMODE_SET, val |
		       (par->bgr ? MODE_SWAP_BGR : 0));

	write_reg(par, SEPS525_DDRAM_DATA_ACCESS_PORT);

	return 0;
}

static struct fbtft_display display = {
	.regwidth = 8,
	.width = WIDTH,
	.height = HEIGHT,
	.fbtftops = {
		.init_display = init_display,
		.set_addr_win = set_addr_win,
		.set_var = set_var,
	},
};

FBTFT_REGISTER_DRIVER(DRVNAME, "syncoam,seps525", &display);

MODULE_ALIAS("spi:" DRVNAME);
MODULE_ALIAS("platform:" DRVNAME);
MODULE_ALIAS("spi:seps525");
MODULE_ALIAS("platform:seps525");

MODULE_DESCRIPTION("FB driver for the SEPS525 LCD Controller");
MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_LICENSE("GPL");