Thomas Petazzoni | 9518dbc | 2014-12-31 10:11:31 +0100 | [diff] [blame] | 1 | /* |
| 2 | * FB driver for the TLS8204 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) 2013 Noralf Tronnes |
| 8 | * Copyright (C) 2014 Michael Hope (adapted for the TLS8204) |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of the GNU General Public License as published by |
| 12 | * the Free Software Foundation; either version 2 of the License, or |
| 13 | * (at your option) any later version. |
| 14 | * |
| 15 | * This program is distributed in the hope that it will be useful, |
| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | * GNU General Public License for more details. |
Thomas Petazzoni | 9518dbc | 2014-12-31 10:11:31 +0100 | [diff] [blame] | 19 | */ |
| 20 | |
| 21 | #include <linux/module.h> |
| 22 | #include <linux/kernel.h> |
| 23 | #include <linux/init.h> |
| 24 | #include <linux/gpio.h> |
| 25 | #include <linux/spi/spi.h> |
| 26 | #include <linux/delay.h> |
| 27 | |
| 28 | #include "fbtft.h" |
| 29 | |
| 30 | #define DRVNAME "fb_tls8204" |
| 31 | #define WIDTH 84 |
| 32 | #define HEIGHT 48 |
| 33 | #define TXBUFLEN WIDTH |
Anton Gerasimov | 3c58845 | 2015-06-13 22:23:47 +0300 | [diff] [blame] | 34 | |
| 35 | /* gamma is used to control contrast in this driver */ |
| 36 | #define DEFAULT_GAMMA "40" |
Thomas Petazzoni | 9518dbc | 2014-12-31 10:11:31 +0100 | [diff] [blame] | 37 | |
| 38 | static unsigned bs = 4; |
| 39 | module_param(bs, uint, 0); |
| 40 | MODULE_PARM_DESC(bs, "BS[2:0] Bias voltage level: 0-7 (default: 4)"); |
| 41 | |
| 42 | static int init_display(struct fbtft_par *par) |
| 43 | { |
Thomas Petazzoni | 9518dbc | 2014-12-31 10:11:31 +0100 | [diff] [blame] | 44 | par->fbtftops.reset(par); |
| 45 | |
| 46 | /* Enter extended command mode */ |
| 47 | write_reg(par, 0x21); /* 5:1 1 |
| 48 | 2:0 PD - Powerdown control: chip is active |
| 49 | 1:0 V - Entry mode: horizontal addressing |
Anton Gerasimov | 3c58845 | 2015-06-13 22:23:47 +0300 | [diff] [blame] | 50 | 0:1 H - Extended instruction set control: |
| 51 | extended |
Thomas Petazzoni | 9518dbc | 2014-12-31 10:11:31 +0100 | [diff] [blame] | 52 | */ |
| 53 | |
| 54 | /* H=1 Bias system */ |
| 55 | write_reg(par, 0x10 | (bs & 0x7)); /* |
| 56 | 4:1 1 |
| 57 | 3:0 0 |
| 58 | 2:x BS2 - Bias System |
| 59 | 1:x BS1 |
| 60 | 0:x BS0 |
| 61 | */ |
| 62 | |
| 63 | /* Set the address of the first display line. */ |
| 64 | write_reg(par, 0x04 | (64 >> 6)); |
| 65 | write_reg(par, 0x40 | (64 & 0x3F)); |
| 66 | |
| 67 | /* Enter H=0 standard command mode */ |
| 68 | write_reg(par, 0x20); |
| 69 | |
| 70 | /* H=0 Display control */ |
| 71 | write_reg(par, 0x08 | 4); /* |
| 72 | 3:1 1 |
| 73 | 2:1 D - DE: 10=normal mode |
| 74 | 1:0 0 |
| 75 | 0:0 E |
| 76 | */ |
| 77 | |
| 78 | return 0; |
| 79 | } |
| 80 | |
| 81 | static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye) |
| 82 | { |
Thomas Petazzoni | 9518dbc | 2014-12-31 10:11:31 +0100 | [diff] [blame] | 83 | /* H=0 Set X address of RAM */ |
| 84 | write_reg(par, 0x80); /* 7:1 1 |
| 85 | 6-0: X[6:0] - 0x00 |
| 86 | */ |
| 87 | |
| 88 | /* H=0 Set Y address of RAM */ |
| 89 | write_reg(par, 0x40); /* 7:0 0 |
| 90 | 6:1 1 |
| 91 | 2-0: Y[2:0] - 0x0 |
| 92 | */ |
| 93 | } |
| 94 | |
| 95 | static int write_vmem(struct fbtft_par *par, size_t offset, size_t len) |
| 96 | { |
Lars Svensson | 4b6dc17 | 2015-10-07 09:20:13 +0200 | [diff] [blame] | 97 | u16 *vmem16 = (u16 *)par->info->screen_buffer; |
Thomas Petazzoni | 9518dbc | 2014-12-31 10:11:31 +0100 | [diff] [blame] | 98 | int x, y, i; |
| 99 | int ret = 0; |
| 100 | |
Anish Bhatt | 94c0a54 | 2015-09-03 00:53:37 -0700 | [diff] [blame] | 101 | for (y = 0; y < HEIGHT / 8; y++) { |
Thomas Petazzoni | 9518dbc | 2014-12-31 10:11:31 +0100 | [diff] [blame] | 102 | u8 *buf = par->txbuf.buf; |
| 103 | /* The display is 102x68 but the LCD is 84x48. Set |
| 104 | the write pointer at the start of each row. */ |
| 105 | gpio_set_value(par->gpio.dc, 0); |
| 106 | write_reg(par, 0x80 | 0); |
| 107 | write_reg(par, 0x40 | y); |
| 108 | |
| 109 | for (x = 0; x < WIDTH; x++) { |
| 110 | u8 ch = 0; |
Charlie Wong Super | a94ac15 | 2015-04-04 20:54:56 +0800 | [diff] [blame] | 111 | |
Anish Bhatt | 94c0a54 | 2015-09-03 00:53:37 -0700 | [diff] [blame] | 112 | for (i = 0; i < 8 * WIDTH; i += WIDTH) { |
Thomas Petazzoni | 9518dbc | 2014-12-31 10:11:31 +0100 | [diff] [blame] | 113 | ch >>= 1; |
Anish Bhatt | 94c0a54 | 2015-09-03 00:53:37 -0700 | [diff] [blame] | 114 | if (vmem16[(y * 8 * WIDTH) + i + x]) |
Thomas Petazzoni | 9518dbc | 2014-12-31 10:11:31 +0100 | [diff] [blame] | 115 | ch |= 0x80; |
| 116 | } |
| 117 | *buf++ = ch; |
| 118 | } |
| 119 | /* Write the row */ |
| 120 | gpio_set_value(par->gpio.dc, 1); |
| 121 | ret = par->fbtftops.write(par, par->txbuf.buf, WIDTH); |
| 122 | if (ret < 0) { |
| 123 | dev_err(par->info->device, |
Haneen Mohammed | aed1c72 | 2015-03-06 21:59:04 +0300 | [diff] [blame] | 124 | "write failed and returned: %d\n", ret); |
Thomas Petazzoni | 9518dbc | 2014-12-31 10:11:31 +0100 | [diff] [blame] | 125 | break; |
| 126 | } |
| 127 | } |
| 128 | |
| 129 | return ret; |
| 130 | } |
| 131 | |
| 132 | static int set_gamma(struct fbtft_par *par, unsigned long *curves) |
| 133 | { |
Thomas Petazzoni | 9518dbc | 2014-12-31 10:11:31 +0100 | [diff] [blame] | 134 | /* apply mask */ |
| 135 | curves[0] &= 0x7F; |
| 136 | |
| 137 | write_reg(par, 0x21); /* turn on extended instruction set */ |
| 138 | write_reg(par, 0x80 | curves[0]); |
| 139 | write_reg(par, 0x20); /* turn off extended instruction set */ |
| 140 | |
| 141 | return 0; |
| 142 | } |
| 143 | |
Thomas Petazzoni | 9518dbc | 2014-12-31 10:11:31 +0100 | [diff] [blame] | 144 | static struct fbtft_display display = { |
| 145 | .regwidth = 8, |
| 146 | .width = WIDTH, |
| 147 | .height = HEIGHT, |
| 148 | .txbuflen = TXBUFLEN, |
| 149 | .gamma_num = 1, |
| 150 | .gamma_len = 1, |
| 151 | .gamma = DEFAULT_GAMMA, |
| 152 | .fbtftops = { |
| 153 | .init_display = init_display, |
| 154 | .set_addr_win = set_addr_win, |
| 155 | .write_vmem = write_vmem, |
| 156 | .set_gamma = set_gamma, |
| 157 | }, |
| 158 | .backlight = 1, |
| 159 | }; |
Anish Bhatt | 1014c2c | 2015-09-03 00:53:36 -0700 | [diff] [blame] | 160 | |
Thomas Petazzoni | 9518dbc | 2014-12-31 10:11:31 +0100 | [diff] [blame] | 161 | FBTFT_REGISTER_DRIVER(DRVNAME, "teralane,tls8204", &display); |
| 162 | |
| 163 | MODULE_ALIAS("spi:" DRVNAME); |
| 164 | MODULE_ALIAS("spi:tls8204"); |
| 165 | |
| 166 | MODULE_DESCRIPTION("FB driver for the TLS8204 LCD Controller"); |
| 167 | MODULE_AUTHOR("Michael Hope"); |
| 168 | MODULE_LICENSE("GPL"); |