1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * FB driver for the SH1106 OLED Controller |
4 | * Based on the SSD1306 driver by Noralf Tronnes |
5 | * |
6 | * Copyright (C) 2017 Heiner Kallweit |
7 | */ |
8 | |
9 | #include <linux/module.h> |
10 | #include <linux/kernel.h> |
11 | #include <linux/init.h> |
12 | #include <linux/delay.h> |
13 | |
14 | #include "fbtft.h" |
15 | |
16 | #define DRVNAME "fb_sh1106" |
17 | #define WIDTH 128 |
18 | #define HEIGHT 64 |
19 | |
20 | /* Init sequence based on the Adafruit SSD1306 Arduino library */ |
21 | static int init_display(struct fbtft_par *par) |
22 | { |
23 | if (!par->info->var.xres || par->info->var.xres > WIDTH || |
24 | !par->info->var.yres || par->info->var.yres > HEIGHT || |
25 | par->info->var.yres % 8) { |
26 | dev_err(par->info->device, "Invalid screen size\n" ); |
27 | return -EINVAL; |
28 | } |
29 | |
30 | if (par->info->var.rotate) { |
31 | dev_err(par->info->device, "Display rotation not supported\n" ); |
32 | return -EINVAL; |
33 | } |
34 | |
35 | par->fbtftops.reset(par); |
36 | |
37 | /* Set Display OFF */ |
38 | write_reg(par, 0xAE); |
39 | |
40 | /* Set Display Clock Divide Ratio/ Oscillator Frequency */ |
41 | write_reg(par, 0xD5, 0x80); |
42 | |
43 | /* Set Multiplex Ratio */ |
44 | write_reg(par, 0xA8, par->info->var.yres - 1); |
45 | |
46 | /* Set Display Offset */ |
47 | write_reg(par, 0xD3, 0x00); |
48 | |
49 | /* Set Display Start Line */ |
50 | write_reg(par, 0x40 | 0x0); |
51 | |
52 | /* Set Segment Re-map */ |
53 | /* column address 127 is mapped to SEG0 */ |
54 | write_reg(par, 0xA0 | 0x1); |
55 | |
56 | /* Set COM Output Scan Direction */ |
57 | /* remapped mode. Scan from COM[N-1] to COM0 */ |
58 | write_reg(par, 0xC8); |
59 | |
60 | /* Set COM Pins Hardware Configuration */ |
61 | if (par->info->var.yres == 64) |
62 | /* A[4]=1b, Alternative COM pin configuration */ |
63 | write_reg(par, 0xDA, 0x12); |
64 | else if (par->info->var.yres == 48) |
65 | /* A[4]=1b, Alternative COM pin configuration */ |
66 | write_reg(par, 0xDA, 0x12); |
67 | else |
68 | /* A[4]=0b, Sequential COM pin configuration */ |
69 | write_reg(par, 0xDA, 0x02); |
70 | |
71 | /* Set Pre-charge Period */ |
72 | write_reg(par, 0xD9, 0xF1); |
73 | |
74 | /* Set VCOMH Deselect Level */ |
75 | write_reg(par, 0xDB, 0x40); |
76 | |
77 | /* Set Display ON */ |
78 | write_reg(par, 0xAF); |
79 | |
80 | msleep(msecs: 150); |
81 | |
82 | return 0; |
83 | } |
84 | |
85 | static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye) |
86 | { |
87 | } |
88 | |
89 | static int blank(struct fbtft_par *par, bool on) |
90 | { |
91 | fbtft_par_dbg(DEBUG_BLANK, par, "(%s=%s)\n" , |
92 | __func__, on ? "true" : "false" ); |
93 | |
94 | write_reg(par, on ? 0xAE : 0xAF); |
95 | |
96 | return 0; |
97 | } |
98 | |
99 | /* Gamma is used to control Contrast */ |
100 | static int set_gamma(struct fbtft_par *par, u32 *curves) |
101 | { |
102 | /* apply mask */ |
103 | curves[0] &= 0xFF; |
104 | |
105 | /* Set Contrast Control for BANK0 */ |
106 | write_reg(par, 0x81, curves[0]); |
107 | |
108 | return 0; |
109 | } |
110 | |
111 | static int write_vmem(struct fbtft_par *par, size_t offset, size_t len) |
112 | { |
113 | u16 *vmem16 = (u16 *)par->info->screen_buffer; |
114 | u32 xres = par->info->var.xres; |
115 | int page, page_start, page_end, x, i, ret; |
116 | u8 *buf = par->txbuf.buf; |
117 | |
118 | /* offset refers to vmem with 2 bytes element size */ |
119 | page_start = offset / (8 * 2 * xres); |
120 | page_end = DIV_ROUND_UP(offset + len, 8 * 2 * xres); |
121 | |
122 | for (page = page_start; page < page_end; page++) { |
123 | /* set page and set column to 2 because of vidmem width 132 */ |
124 | write_reg(par, 0xb0 | page, 0x00 | 2, 0x10 | 0); |
125 | |
126 | memset(buf, 0, xres); |
127 | for (x = 0; x < xres; x++) |
128 | for (i = 0; i < 8; i++) |
129 | if (vmem16[(page * 8 + i) * xres + x]) |
130 | buf[x] |= BIT(i); |
131 | |
132 | /* Write data */ |
133 | ret = fbtft_write_buf_dc(par, buf, len: xres, dc: 1); |
134 | if (ret < 0) |
135 | return ret; |
136 | } |
137 | |
138 | return 0; |
139 | } |
140 | |
141 | static void write_register(struct fbtft_par *par, int len, ...) |
142 | { |
143 | va_list args; |
144 | int i; |
145 | |
146 | va_start(args, len); |
147 | |
148 | for (i = 0; i < len; i++) |
149 | par->buf[i] = va_arg(args, unsigned int); |
150 | |
151 | /* keep DC low for all command bytes to transfer */ |
152 | fbtft_write_buf_dc(par, buf: par->buf, len, dc: 0); |
153 | |
154 | va_end(args); |
155 | } |
156 | |
157 | static struct fbtft_display display = { |
158 | .regwidth = 8, |
159 | .width = WIDTH, |
160 | .height = HEIGHT, |
161 | .txbuflen = WIDTH, |
162 | .gamma_num = 1, |
163 | .gamma_len = 1, |
164 | /* set default contrast to 0xcd = 80% */ |
165 | .gamma = "cd" , |
166 | .fbtftops = { |
167 | .write_vmem = write_vmem, |
168 | .write_register = write_register, |
169 | .init_display = init_display, |
170 | .set_addr_win = set_addr_win, |
171 | .blank = blank, |
172 | .set_gamma = set_gamma, |
173 | }, |
174 | }; |
175 | |
176 | FBTFT_REGISTER_SPI_DRIVER(DRVNAME, "sinowealth" , "sh1106" , &display); |
177 | |
178 | MODULE_DESCRIPTION("SH1106 OLED Driver" ); |
179 | MODULE_AUTHOR("Heiner Kallweit" ); |
180 | MODULE_LICENSE("GPL" ); |
181 | |