drivers/staging/fbtft/fb_ssd1331.c

   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
  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
  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
  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         if (!par->gpio.dc)
  85                 gpiod_set_value(par->gpio.dc, 0);
  86         ret = par->fbtftops.write(par, par->buf, sizeof(u8));
  87         if (ret < 0) {
  88                 va_end(args);
  89                 dev_err(par->info->device,
  90                         "write() failed and returned %d\n", ret);
  91                 return;
  92         }
  93         len--;
  94
  95         if (len) {
  96                 i = len;
  97                 while (i--)
  98                         *buf++ = (u8)va_arg(args, unsigned int);
  99                 ret = par->fbtftops.write(par, par->buf, len * (sizeof(u8)));
 100                 if (ret < 0) {
 101                         va_end(args);
 102                         dev_err(par->info->device,
 103                                 "write() failed and returned %d\n", ret);
 104                         return;
 105                 }
 106         }
 107         if (!par->gpio.dc)
 108                 gpiod_set_value(par->gpio.dc, 1);
 109         va_end(args);
 110 }
 111
 112 /*
 113  * Grayscale Lookup Table
 114  * GS1 - GS63
 115  * The driver Gamma curve contains the relative values between the entries
 116  * in the Lookup table.
 117  *
 118  * From datasheet:
 119  * 8.8 Gray Scale Decoder
 120  *
 121  * there are total 180 Gamma Settings (Setting 0 to Setting 180)
 122  * available for the Gray Scale table.
 123  *
 124  * The gray scale is defined in incremental way, with reference
 125  * to the length of previous table entry:
 126  * Setting of GS1 has to be >= 0
 127  * Setting of GS2 has to be > Setting of GS1 +1
 128  * Setting of GS3 has to be > Setting of GS2 +1
 129  * :
 130  * Setting of GS63 has to be > Setting of GS62 +1
 131  *
 132  */
 133 static int set_gamma(struct fbtft_par *par, u32 *curves)
 134 {
 135         unsigned long tmp[GAMMA_NUM * GAMMA_LEN];
 136         int i, acc = 0;
 137
 138         for (i = 0; i < 63; i++) {
 139                 if (i > 0 && curves[i] < 2) {
 140                         dev_err(par->info->device,
 141                                 "Illegal value in Grayscale Lookup Table at index %d. Must be greater than 1\n",
 142                                 i);
 143                         return -EINVAL;
 144                 }
 145                 acc += curves[i];
 146                 tmp[i] = acc;
 147                 if (acc > 180) {
 148                         dev_err(par->info->device,
 149                                 "Illegal value(s) in Grayscale Lookup Table. At index=%d, the accumulated value has exceeded 180\n",
 150                                 i);
 151                         return -EINVAL;
 152                 }
 153         }
 154
 155         write_reg(par, 0xB8,
 156                   tmp[0], tmp[1], tmp[2], tmp[3], tmp[4], tmp[5], tmp[6],
 157                   tmp[7], tmp[8], tmp[9], tmp[10], tmp[11], tmp[12], tmp[13],
 158                   tmp[14], tmp[15], tmp[16], tmp[17], tmp[18], tmp[19], tmp[20],
 159                   tmp[21], tmp[22], tmp[23], tmp[24], tmp[25], tmp[26], tmp[27],
 160                   tmp[28], tmp[29], tmp[30], tmp[31], tmp[32], tmp[33], tmp[34],
 161                   tmp[35], tmp[36], tmp[37], tmp[38], tmp[39], tmp[40], tmp[41],
 162                   tmp[42], tmp[43], tmp[44], tmp[45], tmp[46], tmp[47], tmp[48],
 163                   tmp[49], tmp[50], tmp[51], tmp[52], tmp[53], tmp[54], tmp[55],
 164                   tmp[56], tmp[57], tmp[58], tmp[59], tmp[60], tmp[61],
 165                   tmp[62]);
 166
 167         return 0;
 168 }
 169
 170 static int blank(struct fbtft_par *par, bool on)
 171 {
 172         fbtft_par_dbg(DEBUG_BLANK, par, "(%s=%s)\n",
 173                       __func__, on ? "true" : "false");
 174         if (on)
 175                 write_reg(par, 0xAE);
 176         else
 177                 write_reg(par, 0xAF);
 178         return 0;
 179 }
 180
 181 static struct fbtft_display display = {
 182         .regwidth = 8,
 183         .width = WIDTH,
 184         .height = HEIGHT,
 185         .gamma_num = GAMMA_NUM,
 186         .gamma_len = GAMMA_LEN,
 187         .gamma = DEFAULT_GAMMA,
 188         .fbtftops = {
 189                 .write_register = write_reg8_bus8,
 190                 .init_display = init_display,
 191                 .set_addr_win = set_addr_win,
 192                 .set_gamma = set_gamma,
 193                 .blank = blank,
 194         },
 195 };
 196
 197 FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1331", &display);
 198
 199 MODULE_ALIAS("spi:" DRVNAME);
 200 MODULE_ALIAS("platform:" DRVNAME);
 201 MODULE_ALIAS("spi:ssd1331");
 202 MODULE_ALIAS("platform:ssd1331");
 203
 204 MODULE_DESCRIPTION("SSD1331 OLED Driver");
 205 MODULE_AUTHOR("Alec Smecher (adapted from SSD1351 by James Davies)");
 206 MODULE_LICENSE("GPL");