1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/module.h>
3 #include <linux/kernel.h>
4 #include <linux/init.h>
5 #include <linux/gpio/consumer.h>
6 #include <linux/spi/spi.h>
7 #include <linux/delay.h>
8
9 #include "fbtft.h"
10
11 #define DRVNAME "fb_ssd1331"
12 #define WIDTH 96
13 #define HEIGHT 64
14 #define GAMMA_NUM 1
15 #define GAMMA_LEN 63
16 #define DEFAULT_GAMMA "0 2 2 2 2 2 2 2 " \
17 "2 2 2 2 2 2 2 2 " \
18 "2 2 2 2 2 2 2 2 " \
19 "2 2 2 2 2 2 2 2 " \
20 "2 2 2 2 2 2 2 2 " \
21 "2 2 2 2 2 2 2 2 " \
22 "2 2 2 2 2 2 2 2 " \
23 "2 2 2 2 2 2 2" \
24
init_display(struct fbtft_par * par)25 static int init_display(struct fbtft_par *par)
26 {
27 par->fbtftops.reset(par);
28
29 write_reg(par, 0xae); /* Display Off */
30
31 /* Set Column Address Mapping, COM Scan Direction and Colour Depth */
32 if (par->info->var.rotate == 180)
33 write_reg(par, 0xa0, 0x60 | (par->bgr << 2));
34 else
35 write_reg(par, 0xa0, 0x72 | (par->bgr << 2));
36
37 write_reg(par, 0x72); /* RGB colour */
38 write_reg(par, 0xa1, 0x00); /* Set Display Start Line */
39 write_reg(par, 0xa2, 0x00); /* Set Display Offset */
40 write_reg(par, 0xa4); /* NORMALDISPLAY */
41 write_reg(par, 0xa8, 0x3f); /* Set multiplex */
42 write_reg(par, 0xad, 0x8e); /* Set master */
43 /* write_reg(par, 0xb0, 0x0b); Set power mode */
44 write_reg(par, 0xb1, 0x31); /* Precharge */
45 write_reg(par, 0xb3, 0xf0); /* Clock div */
46 write_reg(par, 0x8a, 0x64); /* Precharge A */
47 write_reg(par, 0x8b, 0x78); /* Precharge B */
48 write_reg(par, 0x8c, 0x64); /* Precharge C */
49 write_reg(par, 0xbb, 0x3a); /* Precharge level */
50 write_reg(par, 0xbe, 0x3e); /* vcomh */
51 write_reg(par, 0x87, 0x06); /* Master current */
52 write_reg(par, 0x81, 0x91); /* Contrast A */
53 write_reg(par, 0x82, 0x50); /* Contrast B */
54 write_reg(par, 0x83, 0x7d); /* Contrast C */
55 write_reg(par, 0xaf); /* Set Sleep Mode Display On */
56
57 return 0;
58 }
59
set_addr_win(struct fbtft_par * par,int xs,int ys,int xe,int ye)60 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
61 {
62 write_reg(par, 0x15, xs, xe);
63 write_reg(par, 0x75, ys, ye);
64 }
65
write_reg8_bus8(struct fbtft_par * par,int len,...)66 static void write_reg8_bus8(struct fbtft_par *par, int len, ...)
67 {
68 va_list args;
69 int i, ret;
70 u8 *buf = par->buf;
71
72 if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {
73 va_start(args, len);
74 for (i = 0; i < len; i++)
75 buf[i] = (u8)va_arg(args, unsigned int);
76 va_end(args);
77 fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par, par->info->device,
78 u8, buf, len, "%s: ", __func__);
79 }
80
81 va_start(args, len);
82
83 *buf = (u8)va_arg(args, unsigned int);
84 gpiod_set_value(par->gpio.dc, 0);
85 ret = par->fbtftops.write(par, par->buf, sizeof(u8));
86 if (ret < 0) {
87 va_end(args);
88 dev_err(par->info->device,
89 "write() failed and returned %d\n", ret);
90 return;
91 }
92 len--;
93
94 if (len) {
95 i = len;
96 while (i--)
97 *buf++ = (u8)va_arg(args, unsigned int);
98 ret = par->fbtftops.write(par, par->buf, len * (sizeof(u8)));
99 if (ret < 0) {
100 va_end(args);
101 dev_err(par->info->device,
102 "write() failed and returned %d\n", ret);
103 return;
104 }
105 }
106 gpiod_set_value(par->gpio.dc, 1);
107 va_end(args);
108 }
109
110 /*
111 * Grayscale Lookup Table
112 * GS1 - GS63
113 * The driver Gamma curve contains the relative values between the entries
114 * in the Lookup table.
115 *
116 * From datasheet:
117 * 8.8 Gray Scale Decoder
118 *
119 * there are total 180 Gamma Settings (Setting 0 to Setting 180)
120 * available for the Gray Scale table.
121 *
122 * The gray scale is defined in incremental way, with reference
123 * to the length of previous table entry:
124 * Setting of GS1 has to be >= 0
125 * Setting of GS2 has to be > Setting of GS1 +1
126 * Setting of GS3 has to be > Setting of GS2 +1
127 * :
128 * Setting of GS63 has to be > Setting of GS62 +1
129 *
130 */
set_gamma(struct fbtft_par * par,u32 * curves)131 static int set_gamma(struct fbtft_par *par, u32 *curves)
132 {
133 unsigned long tmp[GAMMA_NUM * GAMMA_LEN];
134 int i, acc = 0;
135
136 for (i = 0; i < 63; i++) {
137 if (i > 0 && curves[i] < 2) {
138 dev_err(par->info->device,
139 "Illegal value in Grayscale Lookup Table at index %d. Must be greater than 1\n",
140 i);
141 return -EINVAL;
142 }
143 acc += curves[i];
144 tmp[i] = acc;
145 if (acc > 180) {
146 dev_err(par->info->device,
147 "Illegal value(s) in Grayscale Lookup Table. At index=%d, the accumulated value has exceeded 180\n",
148 i);
149 return -EINVAL;
150 }
151 }
152
153 write_reg(par, 0xB8,
154 tmp[0], tmp[1], tmp[2], tmp[3], tmp[4], tmp[5], tmp[6],
155 tmp[7], tmp[8], tmp[9], tmp[10], tmp[11], tmp[12], tmp[13],
156 tmp[14], tmp[15], tmp[16], tmp[17], tmp[18], tmp[19], tmp[20],
157 tmp[21], tmp[22], tmp[23], tmp[24], tmp[25], tmp[26], tmp[27],
158 tmp[28], tmp[29], tmp[30], tmp[31], tmp[32], tmp[33], tmp[34],
159 tmp[35], tmp[36], tmp[37], tmp[38], tmp[39], tmp[40], tmp[41],
160 tmp[42], tmp[43], tmp[44], tmp[45], tmp[46], tmp[47], tmp[48],
161 tmp[49], tmp[50], tmp[51], tmp[52], tmp[53], tmp[54], tmp[55],
162 tmp[56], tmp[57], tmp[58], tmp[59], tmp[60], tmp[61],
163 tmp[62]);
164
165 return 0;
166 }
167
blank(struct fbtft_par * par,bool on)168 static int blank(struct fbtft_par *par, bool on)
169 {
170 fbtft_par_dbg(DEBUG_BLANK, par, "(%s=%s)\n",
171 __func__, on ? "true" : "false");
172 if (on)
173 write_reg(par, 0xAE);
174 else
175 write_reg(par, 0xAF);
176 return 0;
177 }
178
179 static struct fbtft_display display = {
180 .regwidth = 8,
181 .width = WIDTH,
182 .height = HEIGHT,
183 .gamma_num = GAMMA_NUM,
184 .gamma_len = GAMMA_LEN,
185 .gamma = DEFAULT_GAMMA,
186 .fbtftops = {
187 .write_register = write_reg8_bus8,
188 .init_display = init_display,
189 .set_addr_win = set_addr_win,
190 .set_gamma = set_gamma,
191 .blank = blank,
192 },
193 };
194
195 FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1331", &display);
196
197 MODULE_ALIAS("spi:" DRVNAME);
198 MODULE_ALIAS("platform:" DRVNAME);
199 MODULE_ALIAS("spi:ssd1331");
200 MODULE_ALIAS("platform:ssd1331");
201
202 MODULE_DESCRIPTION("SSD1331 OLED Driver");
203 MODULE_AUTHOR("Alec Smecher (adapted from SSD1351 by James Davies)");
204 MODULE_LICENSE("GPL");
205