1 // SPDX-License-Identifier: GPL-2.0+
3 * FB driver for the SH1106 OLED Controller
4 * Based on the SSD1306 driver by Noralf Tronnes
6 * Copyright (C) 2017 Heiner Kallweit
9 #include <linux/module.h>
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/gpio/consumer.h>
13 #include <linux/delay.h>
17 #define DRVNAME "fb_sh1106"
21 /* Init sequence based on the Adafruit SSD1306 Arduino library */
22 static int init_display(struct fbtft_par *par)
24 if (!par->info->var.xres || par->info->var.xres > WIDTH ||
25 !par->info->var.yres || par->info->var.yres > HEIGHT ||
26 par->info->var.yres % 8) {
27 dev_err(par->info->device, "Invalid screen size\n");
31 if (par->info->var.rotate) {
32 dev_err(par->info->device, "Display rotation not supported\n");
36 par->fbtftops.reset(par);
41 /* Set Display Clock Divide Ratio/ Oscillator Frequency */
42 write_reg(par, 0xD5, 0x80);
44 /* Set Multiplex Ratio */
45 write_reg(par, 0xA8, par->info->var.yres - 1);
47 /* Set Display Offset */
48 write_reg(par, 0xD3, 0x00);
50 /* Set Display Start Line */
51 write_reg(par, 0x40 | 0x0);
53 /* Set Segment Re-map */
54 /* column address 127 is mapped to SEG0 */
55 write_reg(par, 0xA0 | 0x1);
57 /* Set COM Output Scan Direction */
58 /* remapped mode. Scan from COM[N-1] to COM0 */
61 /* Set COM Pins Hardware Configuration */
62 if (par->info->var.yres == 64)
63 /* A[4]=1b, Alternative COM pin configuration */
64 write_reg(par, 0xDA, 0x12);
65 else if (par->info->var.yres == 48)
66 /* A[4]=1b, Alternative COM pin configuration */
67 write_reg(par, 0xDA, 0x12);
69 /* A[4]=0b, Sequential COM pin configuration */
70 write_reg(par, 0xDA, 0x02);
72 /* Set Pre-charge Period */
73 write_reg(par, 0xD9, 0xF1);
75 /* Set VCOMH Deselect Level */
76 write_reg(par, 0xDB, 0x40);
86 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
90 static int blank(struct fbtft_par *par, bool on)
92 fbtft_par_dbg(DEBUG_BLANK, par, "(%s=%s)\n",
93 __func__, on ? "true" : "false");
95 write_reg(par, on ? 0xAE : 0xAF);
100 /* Gamma is used to control Contrast */
101 static int set_gamma(struct fbtft_par *par, u32 *curves)
106 /* Set Contrast Control for BANK0 */
107 write_reg(par, 0x81, curves[0]);
112 static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
114 u16 *vmem16 = (u16 *)par->info->screen_buffer;
115 u32 xres = par->info->var.xres;
116 int page, page_start, page_end, x, i, ret;
117 u8 *buf = par->txbuf.buf;
119 /* offset refers to vmem with 2 bytes element size */
120 page_start = offset / (8 * 2 * xres);
121 page_end = DIV_ROUND_UP(offset + len, 8 * 2 * xres);
123 for (page = page_start; page < page_end; page++) {
124 /* set page and set column to 2 because of vidmem width 132 */
125 write_reg(par, 0xb0 | page, 0x00 | 2, 0x10 | 0);
127 memset(buf, 0, xres);
128 for (x = 0; x < xres; x++)
129 for (i = 0; i < 8; i++)
130 if (vmem16[(page * 8 + i) * xres + x])
134 ret = fbtft_write_buf_dc(par, buf, xres, 1);
142 static void write_register(struct fbtft_par *par, int len, ...)
149 for (i = 0; i < len; i++)
150 par->buf[i] = va_arg(args, unsigned int);
152 /* keep DC low for all command bytes to transfer */
153 fbtft_write_buf_dc(par, par->buf, len, 0);
158 static struct fbtft_display display = {
165 /* set default contrast to 0xcd = 80% */
168 .write_vmem = write_vmem,
169 .write_register = write_register,
170 .init_display = init_display,
171 .set_addr_win = set_addr_win,
173 .set_gamma = set_gamma,
177 FBTFT_REGISTER_DRIVER(DRVNAME, "sinowealth,sh1106", &display);
179 MODULE_ALIAS("spi:" DRVNAME);
180 MODULE_ALIAS("platform:" DRVNAME);
181 MODULE_ALIAS("spi:sh1106");
182 MODULE_ALIAS("platform:sh1106");
184 MODULE_DESCRIPTION("SH1106 OLED Driver");
185 MODULE_AUTHOR("Heiner Kallweit");
186 MODULE_LICENSE("GPL");