LXR linux/drivers/staging/fbtft/fb

   1/*
   2 * FB driver for the UC1701 LCD Controller
   3 *
   4 * The display is monochrome and the video memory is RGB565.
   5 * Any pixel value except 0 turns the pixel on.
   6 *
   7 * Copyright (C) 2014 Juergen Holzmann
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License as published by
  11 * the Free Software Foundation; either version 2 of the License, or
  12 * (at your option) any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 * GNU General Public License for more details.
  18 */
  19
  20#include <linux/module.h>
  21#include <linux/kernel.h>
  22#include <linux/init.h>
  23#include <linux/gpio.h>
  24#include <linux/spi/spi.h>
  25#include <linux/delay.h>
  26
  27#include "fbtft.h"
  28
  29#define DRVNAME "fb_uc1701"
  30#define WIDTH     102
  31#define HEIGHT   64
  32#define PAGES     (HEIGHT / 8)
  33
  34/* 1: Display on/off */
  35#define LCD_DISPLAY_ENABLE    0xAE
  36/* 2: display start line set */
  37#define LCD_START_LINE  0x40
  38/* 3: Page address set (lower 4 bits select one of the pages) */
  39#define LCD_PAGE_ADDRESS      0xB0
  40/* 4: column address */
  41#define LCD_COL_ADDRESS       0x10
  42/* 8: select orientation */
  43#define LCD_BOTTOMVIEW  0xA0
  44/* 9: inverted display */
  45#define LCD_DISPLAY_INVERT    0xA6
  46/* 10: show memory content or switch all pixels on */
  47#define LCD_ALL_PIXEL    0xA4
  48/* 11: lcd bias set */
  49#define LCD_BIAS              0xA2
  50/* 14: Reset Controller */
  51#define LCD_RESET_CMD    0xE2
  52/* 15: output mode select (turns display upside-down) */
  53#define LCD_SCAN_DIR      0xC0
  54/* 16: power control set */
  55#define LCD_POWER_CONTROL     0x28
  56/* 17: voltage regulator resistor ratio set */
  57#define LCD_VOLTAGE        0x20
  58/* 18: Volume mode set */
  59#define LCD_VOLUME_MODE       0x81
  60/* 22: NOP command */
  61#define LCD_NO_OP            0xE3
  62/* 25: advanced program control */
  63#define LCD_ADV_PROG_CTRL     0xFA
  64/* 25: advanced program control2 */
  65#define LCD_ADV_PROG_CTRL2    0x10
  66#define LCD_TEMPCOMP_HIGH     0x80
  67/* column offset for normal orientation */
  68#define SHIFT_ADDR_NORMAL     0
  69/* column offset for bottom view orientation */
  70#define SHIFT_ADDR_TOPVIEW    30
  71
  72static int init_display(struct fbtft_par *par)
  73{
  74        par->fbtftops.reset(par);
  75
  76        /* softreset of LCD */
  77        write_reg(par, LCD_RESET_CMD);
  78        mdelay(10);
  79
  80        /* set startpoint */
  81        write_reg(par, LCD_START_LINE);
  82
  83        /* select orientation BOTTOMVIEW */
  84        write_reg(par, LCD_BOTTOMVIEW | 1);
  85
  86        /* output mode select (turns display upside-down) */
  87        write_reg(par, LCD_SCAN_DIR | 0x00);
  88
  89        /* Normal Pixel mode */
  90        write_reg(par, LCD_ALL_PIXEL | 0);
  91
  92        /* positive display */
  93        write_reg(par, LCD_DISPLAY_INVERT | 0);
  94
  95        /* bias 1/9 */
  96        write_reg(par, LCD_BIAS | 0);
  97
  98        /* power control mode: all features on */
  99        write_reg(par, LCD_POWER_CONTROL | 0x07);
 100
 101        /* set voltage regulator R/R */
 102        write_reg(par, LCD_VOLTAGE | 0x07);
 103
 104        /* volume mode set */
 105        write_reg(par, LCD_VOLUME_MODE);
 106        write_reg(par, 0x09);
 107        write_reg(par, LCD_NO_OP);
 108
 109        /* advanced program control */
 110        write_reg(par, LCD_ADV_PROG_CTRL);
 111        write_reg(par, LCD_ADV_PROG_CTRL2 | LCD_TEMPCOMP_HIGH);
 112
 113        /* enable display */
 114        write_reg(par, LCD_DISPLAY_ENABLE | 1);
 115
 116        return 0;
 117}
 118
 119static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
 120{
 121        /* goto address */
 122        write_reg(par, LCD_PAGE_ADDRESS);
 123        write_reg(par, 0x00);
 124        write_reg(par, LCD_COL_ADDRESS);
 125}
 126
 127static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
 128{
 129        u16 *vmem16 = (u16 *)par->info->screen_buffer;
 130        u8 *buf = par->txbuf.buf;
 131        int x, y, i;
 132        int ret = 0;
 133
 134        for (y = 0; y < PAGES; y++) {
 135                buf = par->txbuf.buf;
 136                for (x = 0; x < WIDTH; x++) {
 137                        *buf = 0x00;
 138                        for (i = 0; i < 8; i++)
 139                                *buf |= (vmem16[((y * 8 * WIDTH) +
 140                                                 (i * WIDTH)) + x] ?
 141                                         1 : 0) << i;
 142                        buf++;
 143                }
 144
 145                write_reg(par, LCD_PAGE_ADDRESS | (u8)y);
 146                write_reg(par, 0x00);
 147                write_reg(par, LCD_COL_ADDRESS);
 148                gpio_set_value(par->gpio.dc, 1);
 149                ret = par->fbtftops.write(par, par->txbuf.buf, WIDTH);
 150                gpio_set_value(par->gpio.dc, 0);
 151        }
 152
 153        if (ret < 0)
 154                dev_err(par->info->device, "write failed and returned: %d\n",
 155                        ret);
 156
 157        return ret;
 158}
 159
 160static struct fbtft_display display = {
 161        .regwidth = 8,
 162        .width = WIDTH,
 163        .height = HEIGHT,
 164        .fbtftops = {
 165                .init_display = init_display,
 166                .set_addr_win = set_addr_win,
 167                .write_vmem = write_vmem,
 168        },
 169        .backlight = 1,
 170};
 171
 172FBTFT_REGISTER_DRIVER(DRVNAME, "UltraChip,uc1701", &display);
 173
 174MODULE_ALIAS("spi:" DRVNAME);
 175MODULE_ALIAS("spi:uc1701");
 176
 177MODULE_DESCRIPTION("FB driver for the UC1701 LCD Controller");
 178MODULE_AUTHOR("Juergen Holzmann");
 179MODULE_LICENSE("GPL");
 180