1 #include <linux/module.h>
2 #include <linux/kernel.h>
3 #include <linux/init.h>
4 #include <linux/gpio.h>
5 #include <linux/spi/spi.h>
6 #include <linux/delay.h>
7
8 #include "fbtft.h"
9
10 #define DRVNAME "fb_ssd1331"
11 #define WIDTH 96
12 #define HEIGHT 64
13 #define GAMMA_NUM 1
14 #define GAMMA_LEN 63
15 #define DEFAULT_GAMMA "0 2 2 2 2 2 2 2 " \
16 "2 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" \
23
init_display(struct fbtft_par * par)24 static int init_display(struct fbtft_par *par)
25 {
26 par->fbtftops.reset(par);
27
28 write_reg(par, 0xae); /* Display Off */
29 write_reg(par, 0xa0, 0x70 | (par->bgr << 2)); /* Set Colour Depth */
30 write_reg(par, 0x72); /* RGB colour */
31 write_reg(par, 0xa1, 0x00); /* Set Display Start Line */
32 write_reg(par, 0xa2, 0x00); /* Set Display Offset */
33 write_reg(par, 0xa4); /* NORMALDISPLAY */
34 write_reg(par, 0xa8, 0x3f); /* Set multiplex */
35 write_reg(par, 0xad, 0x8e); /* Set master */
36 /* write_reg(par, 0xb0, 0x0b); Set power mode */
37 write_reg(par, 0xb1, 0x31); /* Precharge */
38 write_reg(par, 0xb3, 0xf0); /* Clock div */
39 write_reg(par, 0x8a, 0x64); /* Precharge A */
40 write_reg(par, 0x8b, 0x78); /* Precharge B */
41 write_reg(par, 0x8c, 0x64); /* Precharge C */
42 write_reg(par, 0xbb, 0x3a); /* Precharge level */
43 write_reg(par, 0xbe, 0x3e); /* vcomh */
44 write_reg(par, 0x87, 0x06); /* Master current */
45 write_reg(par, 0x81, 0x91); /* Contrast A */
46 write_reg(par, 0x82, 0x50); /* Contrast B */
47 write_reg(par, 0x83, 0x7d); /* Contrast C */
48 write_reg(par, 0xaf); /* Set Sleep Mode Display On */
49
50 return 0;
51 }
52
set_addr_win(struct fbtft_par * par,int xs,int ys,int xe,int ye)53 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
54 {
55 write_reg(par, 0x15, xs, xe);
56 write_reg(par, 0x75, ys, ye);
57 }
58
write_reg8_bus8(struct fbtft_par * par,int len,...)59 static void write_reg8_bus8(struct fbtft_par *par, int len, ...)
60 {
61 va_list args;
62 int i, ret;
63 u8 *buf = par->buf;
64
65 if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {
66 va_start(args, len);
67 for (i = 0; i < len; i++)
68 buf[i] = (u8)va_arg(args, unsigned int);
69 va_end(args);
70 fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par, par->info->device, u8, buf, len, "%s: ", __func__);
71 }
72
73 va_start(args, len);
74
75 *buf = (u8)va_arg(args, unsigned int);
76 if (par->gpio.dc != -1)
77 gpio_set_value(par->gpio.dc, 0);
78 ret = par->fbtftops.write(par, par->buf, sizeof(u8));
79 if (ret < 0) {
80 va_end(args);
81 dev_err(par->info->device,
82 "write() failed and returned %d\n", ret);
83 return;
84 }
85 len--;
86
87 if (len) {
88 i = len;
89 while (i--)
90 *buf++ = (u8)va_arg(args, unsigned int);
91 ret = par->fbtftops.write(par, par->buf, len * (sizeof(u8)));
92 if (ret < 0) {
93 va_end(args);
94 dev_err(par->info->device,
95 "write() failed and returned %d\n", ret);
96 return;
97 }
98 }
99 if (par->gpio.dc != -1)
100 gpio_set_value(par->gpio.dc, 1);
101 va_end(args);
102 }
103
104 /*
105 * Grayscale Lookup Table
106 * GS1 - GS63
107 * The driver Gamma curve contains the relative values between the entries
108 * in the Lookup table.
109 *
110 * From datasheet:
111 * 8.8 Gray Scale Decoder
112 *
113 * there are total 180 Gamma Settings (Setting 0 to Setting 180)
114 * available for the Gray Scale table.
115 *
116 * The gray scale is defined in incremental way, with reference
117 * to the length of previous table entry:
118 * Setting of GS1 has to be >= 0
119 * Setting of GS2 has to be > Setting of GS1 +1
120 * Setting of GS3 has to be > Setting of GS2 +1
121 * :
122 * Setting of GS63 has to be > Setting of GS62 +1
123 *
124 */
set_gamma(struct fbtft_par * par,u32 * curves)125 static int set_gamma(struct fbtft_par *par, u32 *curves)
126 {
127 unsigned long tmp[GAMMA_NUM * GAMMA_LEN];
128 int i, acc = 0;
129
130 for (i = 0; i < 63; i++) {
131 if (i > 0 && curves[i] < 2) {
132 dev_err(par->info->device,
133 "Illegal value in Grayscale Lookup Table at index %d. Must be greater than 1\n",
134 i);
135 return -EINVAL;
136 }
137 acc += curves[i];
138 tmp[i] = acc;
139 if (acc > 180) {
140 dev_err(par->info->device,
141 "Illegal value(s) in Grayscale Lookup Table. At index=%d, the accumulated value has exceeded 180\n",
142 i);
143 return -EINVAL;
144 }
145 }
146
147 write_reg(par, 0xB8,
148 tmp[0], tmp[1], tmp[2], tmp[3], tmp[4], tmp[5], tmp[6],
149 tmp[7], tmp[8], tmp[9], tmp[10], tmp[11], tmp[12], tmp[13],
150 tmp[14], tmp[15], tmp[16], tmp[17], tmp[18], tmp[19], tmp[20],
151 tmp[21], tmp[22], tmp[23], tmp[24], tmp[25], tmp[26], tmp[27],
152 tmp[28], tmp[29], tmp[30], tmp[31], tmp[32], tmp[33], tmp[34],
153 tmp[35], tmp[36], tmp[37], tmp[38], tmp[39], tmp[40], tmp[41],
154 tmp[42], tmp[43], tmp[44], tmp[45], tmp[46], tmp[47], tmp[48],
155 tmp[49], tmp[50], tmp[51], tmp[52], tmp[53], tmp[54], tmp[55],
156 tmp[56], tmp[57], tmp[58], tmp[59], tmp[60], tmp[61],
157 tmp[62]);
158
159 return 0;
160 }
161
blank(struct fbtft_par * par,bool on)162 static int blank(struct fbtft_par *par, bool on)
163 {
164 fbtft_par_dbg(DEBUG_BLANK, par, "%s(blank=%s)\n",
165 __func__, on ? "true" : "false");
166 if (on)
167 write_reg(par, 0xAE);
168 else
169 write_reg(par, 0xAF);
170 return 0;
171 }
172
173 static struct fbtft_display display = {
174 .regwidth = 8,
175 .width = WIDTH,
176 .height = HEIGHT,
177 .gamma_num = GAMMA_NUM,
178 .gamma_len = GAMMA_LEN,
179 .gamma = DEFAULT_GAMMA,
180 .fbtftops = {
181 .write_register = write_reg8_bus8,
182 .init_display = init_display,
183 .set_addr_win = set_addr_win,
184 .set_gamma = set_gamma,
185 .blank = blank,
186 },
187 };
188
189 FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1331", &display);
190
191 MODULE_ALIAS("spi:" DRVNAME);
192 MODULE_ALIAS("platform:" DRVNAME);
193 MODULE_ALIAS("spi:ssd1331");
194 MODULE_ALIAS("platform:ssd1331");
195
196 MODULE_DESCRIPTION("SSD1331 OLED Driver");
197 MODULE_AUTHOR("Alec Smecher (adapted from SSD1351 by James Davies)");
198 MODULE_LICENSE("GPL");
199