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 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 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 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 */ 125 static int set_gamma(struct fbtft_par *par, unsigned long *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. " \ 134 "Must be greater than 1\n", 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. " \ 142 "At index=%d, the accumulated value has exceeded 180\n", 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], tmp[7], 149 tmp[8], tmp[9], tmp[10], tmp[11], tmp[12], tmp[13], tmp[14], tmp[15], 150 tmp[16], tmp[17], tmp[18], tmp[19], tmp[20], tmp[21], tmp[22], tmp[23], 151 tmp[24], tmp[25], tmp[26], tmp[27], tmp[28], tmp[29], tmp[30], tmp[31], 152 tmp[32], tmp[33], tmp[34], tmp[35], tmp[36], tmp[37], tmp[38], tmp[39], 153 tmp[40], tmp[41], tmp[42], tmp[43], tmp[44], tmp[45], tmp[46], tmp[47], 154 tmp[48], tmp[49], tmp[50], tmp[51], tmp[52], tmp[53], tmp[54], tmp[55], 155 tmp[56], tmp[57], tmp[58], tmp[59], tmp[60], tmp[61], tmp[62]); 156 157 return 0; 158 } 159 160 static int blank(struct fbtft_par *par, bool on) 161 { 162 fbtft_par_dbg(DEBUG_BLANK, par, "%s(blank=%s)\n", 163 __func__, on ? "true" : "false"); 164 if (on) 165 write_reg(par, 0xAE); 166 else 167 write_reg(par, 0xAF); 168 return 0; 169 } 170 171 static struct fbtft_display display = { 172 .regwidth = 8, 173 .width = WIDTH, 174 .height = HEIGHT, 175 .gamma_num = GAMMA_NUM, 176 .gamma_len = GAMMA_LEN, 177 .gamma = DEFAULT_GAMMA, 178 .fbtftops = { 179 .write_register = write_reg8_bus8, 180 .init_display = init_display, 181 .set_addr_win = set_addr_win, 182 .set_gamma = set_gamma, 183 .blank = blank, 184 }, 185 }; 186 187 FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1331", &display); 188 189 MODULE_ALIAS("spi:" DRVNAME); 190 MODULE_ALIAS("platform:" DRVNAME); 191 MODULE_ALIAS("spi:ssd1331"); 192 MODULE_ALIAS("platform:ssd1331"); 193 194 MODULE_DESCRIPTION("SSD1331 OLED Driver"); 195 MODULE_AUTHOR("Alec Smecher (adapted from SSD1351 by James Davies)"); 196 MODULE_LICENSE("GPL"); 197