2 * FB driver for the SH1106 OLED Controller
3 * Based on the SSD1306 driver by Noralf Tronnes
5 * Copyright (C) 2017 Heiner Kallweit
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
18 #include <linux/module.h>
19 #include <linux/kernel.h>
20 #include <linux/init.h>
21 #include <linux/gpio.h>
22 #include <linux/delay.h>
26 #define DRVNAME "fb_sh1106"
30 /* Init sequence based on the Adafruit SSD1306 Arduino library */
31 static int init_display(struct fbtft_par *par)
33 if (!par->info->var.xres || par->info->var.xres > WIDTH ||
34 !par->info->var.yres || par->info->var.yres > HEIGHT ||
35 par->info->var.yres % 8) {
36 dev_err(par->info->device, "Invalid screen size\n");
40 if (par->info->var.rotate) {
41 dev_err(par->info->device, "Display rotation not supported\n");
45 par->fbtftops.reset(par);
50 /* Set Display Clock Divide Ratio/ Oscillator Frequency */
51 write_reg(par, 0xD5, 0x80);
53 /* Set Multiplex Ratio */
54 write_reg(par, 0xA8, par->info->var.yres - 1);
56 /* Set Display Offset */
57 write_reg(par, 0xD3, 0x00);
59 /* Set Display Start Line */
60 write_reg(par, 0x40 | 0x0);
62 /* Set Segment Re-map */
63 /* column address 127 is mapped to SEG0 */
64 write_reg(par, 0xA0 | 0x1);
66 /* Set COM Output Scan Direction */
67 /* remapped mode. Scan from COM[N-1] to COM0 */
70 /* Set COM Pins Hardware Configuration */
71 if (par->info->var.yres == 64)
72 /* A[4]=1b, Alternative COM pin configuration */
73 write_reg(par, 0xDA, 0x12);
74 else if (par->info->var.yres == 48)
75 /* A[4]=1b, Alternative COM pin configuration */
76 write_reg(par, 0xDA, 0x12);
78 /* A[4]=0b, Sequential COM pin configuration */
79 write_reg(par, 0xDA, 0x02);
81 /* Set Pre-charge Period */
82 write_reg(par, 0xD9, 0xF1);
84 /* Set VCOMH Deselect Level */
85 write_reg(par, 0xDB, 0x40);
95 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
99 static int blank(struct fbtft_par *par, bool on)
101 fbtft_par_dbg(DEBUG_BLANK, par, "%s(blank=%s)\n",
102 __func__, on ? "true" : "false");
104 write_reg(par, on ? 0xAE : 0xAF);
109 /* Gamma is used to control Contrast */
110 static int set_gamma(struct fbtft_par *par, u32 *curves)
115 /* Set Contrast Control for BANK0 */
116 write_reg(par, 0x81, curves[0]);
121 static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
123 u16 *vmem16 = (u16 *)par->info->screen_buffer;
124 u32 xres = par->info->var.xres;
125 int page, page_start, page_end, x, i, ret;
126 u8 *buf = par->txbuf.buf;
128 /* offset refers to vmem with 2 bytes element size */
129 page_start = offset / (8 * 2 * xres);
130 page_end = DIV_ROUND_UP(offset + len, 8 * 2 * xres);
132 for (page = page_start; page < page_end; page++) {
133 /* set page and set column to 2 because of vidmem width 132 */
134 write_reg(par, 0xb0 | page, 0x00 | 2, 0x10 | 0);
136 memset(buf, 0, xres);
137 for (x = 0; x < xres; x++)
138 for (i = 0; i < 8; i++)
139 if (vmem16[(page * 8 + i) * xres + x])
143 ret = fbtft_write_buf_dc(par, buf, xres, 1);
151 static void write_register(struct fbtft_par *par, int len, ...)
158 for (i = 0; i < len; i++)
159 par->buf[i] = va_arg(args, unsigned int);
161 /* keep DC low for all command bytes to transfer */
162 fbtft_write_buf_dc(par, par->buf, len, 0);
167 static struct fbtft_display display = {
174 /* set default contrast to 0xcd = 80% */
177 .write_vmem = write_vmem,
178 .write_register = write_register,
179 .init_display = init_display,
180 .set_addr_win = set_addr_win,
182 .set_gamma = set_gamma,
186 FBTFT_REGISTER_DRIVER(DRVNAME, "sinowealth,sh1106", &display);
188 MODULE_ALIAS("spi:" DRVNAME);
189 MODULE_ALIAS("platform:" DRVNAME);
190 MODULE_ALIAS("spi:sh1106");
191 MODULE_ALIAS("platform:sh1106");
193 MODULE_DESCRIPTION("SH1106 OLED Driver");
194 MODULE_AUTHOR("Heiner Kallweit");
195 MODULE_LICENSE("GPL");