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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 | // SPDX-License-Identifier: GPL-2.0+ /* * FB driver for the SSD1325 OLED Controller */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/gpio/consumer.h> #include <linux/delay.h> #include "fbtft.h" #define DRVNAME "fb_ssd1325" #define WIDTH 128 #define HEIGHT 64 #define GAMMA_NUM 1 #define GAMMA_LEN 15 #define DEFAULT_GAMMA "7 1 1 1 1 2 2 3 3 4 4 5 5 6 6" /* * write_reg() caveat: * * This doesn't work because D/C has to be LOW for both values: * write_reg(par, val1, val2); * * Do it like this: * write_reg(par, val1); * write_reg(par, val2); */ /* Init sequence taken from the Adafruit SSD1306 Arduino library */ static int init_display(struct fbtft_par *par) { par->fbtftops.reset(par); write_reg(par, 0xb3); write_reg(par, 0xf0); write_reg(par, 0xae); write_reg(par, 0xa1); write_reg(par, 0x00); write_reg(par, 0xa8); write_reg(par, 0x3f); write_reg(par, 0xa0); write_reg(par, 0x45); write_reg(par, 0xa2); write_reg(par, 0x40); write_reg(par, 0x75); write_reg(par, 0x00); write_reg(par, 0x3f); write_reg(par, 0x15); write_reg(par, 0x00); write_reg(par, 0x7f); write_reg(par, 0xa4); write_reg(par, 0xaf); return 0; } static uint8_t rgb565_to_g16(u16 pixel) { u16 b = pixel & 0x1f; u16 g = (pixel & (0x3f << 5)) >> 5; u16 r = (pixel & (0x1f << (5 + 6))) >> (5 + 6); pixel = (299 * r + 587 * g + 114 * b) / 195; if (pixel > 255) pixel = 255; return (uint8_t)pixel / 16; } static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye) { fbtft_par_dbg(DEBUG_SET_ADDR_WIN, par, "%s(xs=%d, ys=%d, xe=%d, ye=%d)\n", __func__, xs, ys, xe, ye); write_reg(par, 0x75); write_reg(par, 0x00); write_reg(par, 0x3f); write_reg(par, 0x15); write_reg(par, 0x00); write_reg(par, 0x7f); } static int blank(struct fbtft_par *par, bool on) { fbtft_par_dbg(DEBUG_BLANK, par, "(%s=%s)\n", __func__, on ? "true" : "false"); if (on) write_reg(par, 0xAE); else write_reg(par, 0xAF); return 0; } /* * Grayscale Lookup Table * GS1 - GS15 * The "Gamma curve" contains the relative values between the entries * in the Lookup table. * * 0 = Setting of GS1 < Setting of GS2 < Setting of GS3.....< * Setting of GS14 < Setting of GS15 */ static int set_gamma(struct fbtft_par *par, u32 *curves) { int i; fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__); for (i = 0; i < GAMMA_LEN; i++) { if (i > 0 && curves[i] < 1) { dev_err(par->info->device, "Illegal value in Grayscale Lookup Table at index %d.\n" "Must be greater than 0\n", i); return -EINVAL; } if (curves[i] > 7) { dev_err(par->info->device, "Illegal value(s) in Grayscale Lookup Table.\n" "At index=%d, the accumulated value has exceeded 7\n", i); return -EINVAL; } } write_reg(par, 0xB8); for (i = 0; i < 8; i++) write_reg(par, (curves[i] & 0xFF)); return 0; } static int write_vmem(struct fbtft_par *par, size_t offset, size_t len) { u16 *vmem16 = (u16 *)par->info->screen_buffer; u8 *buf = par->txbuf.buf; u8 n1; u8 n2; int y, x; int ret; for (x = 0; x < par->info->var.xres; x++) { if (x % 2) continue; for (y = 0; y < par->info->var.yres; y++) { n1 = rgb565_to_g16(vmem16[y * par->info->var.xres + x]); n2 = rgb565_to_g16(vmem16 [y * par->info->var.xres + x + 1]); *buf = (n1 << 4) | n2; buf++; } } gpiod_set_value(par->gpio.dc, 1); /* Write data */ ret = par->fbtftops.write(par, par->txbuf.buf, par->info->var.xres * par->info->var.yres / 2); if (ret < 0) dev_err(par->info->device, "%s: write failed and returned: %d\n", __func__, ret); return ret; } static struct fbtft_display display = { .regwidth = 8, .width = WIDTH, .height = HEIGHT, .txbuflen = WIDTH * HEIGHT / 2, .gamma_num = GAMMA_NUM, .gamma_len = GAMMA_LEN, .gamma = DEFAULT_GAMMA, .fbtftops = { .write_vmem = write_vmem, .init_display = init_display, .set_addr_win = set_addr_win, .blank = blank, .set_gamma = set_gamma, }, }; FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1325", &display); MODULE_ALIAS("spi:" DRVNAME); MODULE_ALIAS("platform:" DRVNAME); MODULE_ALIAS("spi:ssd1325"); MODULE_ALIAS("platform:ssd1325"); MODULE_DESCRIPTION("SSD1325 OLED Driver"); MODULE_AUTHOR("Alexey Mednyy"); MODULE_LICENSE("GPL"); |