drivers/staging/fbtft/fb

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This source file includes following definitions.
init_display
set_addr_win
set_var
set_gamma
blank
update_onboard_backlight
register_onboard_backlight
register_onboard_backlight
   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_ssd1351"
  12 #define WIDTH           128
  13 #define HEIGHT          128
  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 void register_onboard_backlight(struct fbtft_par *par);
  26 
  27 static int init_display(struct fbtft_par *par)
  28 {
  29         if (par->pdata &&
  30             par->pdata->display.backlight == FBTFT_ONBOARD_BACKLIGHT) {
  31                 /* module uses onboard GPIO for panel power */
  32                 par->fbtftops.register_backlight = register_onboard_backlight;
  33         }
  34 
  35         par->fbtftops.reset(par);
  36 
  37         write_reg(par, 0xfd, 0x12); /* Command Lock */
  38         write_reg(par, 0xfd, 0xb1); /* Command Lock */
  39         write_reg(par, 0xae); /* Display Off */
  40         write_reg(par, 0xb3, 0xf1); /* Front Clock Div */
  41         write_reg(par, 0xca, 0x7f); /* Set Mux Ratio */
  42         write_reg(par, 0x15, 0x00, 0x7f); /* Set Column Address */
  43         write_reg(par, 0x75, 0x00, 0x7f); /* Set Row Address */
  44         write_reg(par, 0xa1, 0x00); /* Set Display Start Line */
  45         write_reg(par, 0xa2, 0x00); /* Set Display Offset */
  46         write_reg(par, 0xb5, 0x00); /* Set GPIO */
  47         write_reg(par, 0xab, 0x01); /* Set Function Selection */
  48         write_reg(par, 0xb1, 0x32); /* Set Phase Length */
  49         write_reg(par, 0xb4, 0xa0, 0xb5, 0x55); /* Set Segment Low Voltage */
  50         write_reg(par, 0xbb, 0x17); /* Set Precharge Voltage */
  51         write_reg(par, 0xbe, 0x05); /* Set VComH Voltage */
  52         write_reg(par, 0xc1, 0xc8, 0x80, 0xc8); /* Set Contrast */
  53         write_reg(par, 0xc7, 0x0f); /* Set Master Contrast */
  54         write_reg(par, 0xb6, 0x01); /* Set Second Precharge Period */
  55         write_reg(par, 0xa6); /* Set Display Mode Reset */
  56         write_reg(par, 0xaf); /* Set Sleep Mode Display On */
  57 
  58         return 0;
  59 }
  60 
  61 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
  62 {
  63         write_reg(par, 0x15, xs, xe);
  64         write_reg(par, 0x75, ys, ye);
  65         write_reg(par, 0x5c);
  66 }
  67 
  68 static int set_var(struct fbtft_par *par)
  69 {
  70         unsigned int remap;
  71 
  72         if (par->fbtftops.init_display != init_display) {
  73                 /* don't risk messing up register A0h */
  74                 fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
  75                               "%s: skipping since custom init_display() is used\n",
  76                                __func__);
  77                 return 0;
  78         }
  79 
  80         remap = 0x60 | (par->bgr << 2); /* Set Colour Depth */
  81 
  82         switch (par->info->var.rotate) {
  83         case 0:
  84                 write_reg(par, 0xA0, remap | 0x00 | BIT(4));
  85                 break;
  86         case 270:
  87                 write_reg(par, 0xA0, remap | 0x03 | BIT(4));
  88                 break;
  89         case 180:
  90                 write_reg(par, 0xA0, remap | 0x02);
  91                 break;
  92         case 90:
  93                 write_reg(par, 0xA0, remap | 0x01);
  94                 break;
  95         }
  96 
  97         return 0;
  98 }
  99 
 100 /*
 101  * Grayscale Lookup Table
 102  * GS1 - GS63
 103  * The driver Gamma curve contains the relative values between the entries
 104  * in the Lookup table.
 105  *
 106  * From datasheet:
 107  * 8.8 Gray Scale Decoder
 108  *
 109  *      there are total 180 Gamma Settings (Setting 0 to Setting 180)
 110  *      available for the Gray Scale table.
 111  *
 112  *      The gray scale is defined in incremental way, with reference
 113  *      to the length of previous table entry:
 114  *              Setting of GS1 has to be >= 0
 115  *              Setting of GS2 has to be > Setting of GS1 +1
 116  *              Setting of GS3 has to be > Setting of GS2 +1
 117  *              :
 118  *              Setting of GS63 has to be > Setting of GS62 +1
 119  *
 120  */
 121 static int set_gamma(struct fbtft_par *par, u32 *curves)
 122 {
 123         unsigned long tmp[GAMMA_NUM * GAMMA_LEN];
 124         int i, acc = 0;
 125 
 126         for (i = 0; i < 63; i++) {
 127                 if (i > 0 && curves[i] < 2) {
 128                         dev_err(par->info->device,
 129                                 "Illegal value in Grayscale Lookup Table at index %d : %d. Must be greater than 1\n",
 130                                 i, curves[i]);
 131                         return -EINVAL;
 132                 }
 133                 acc += curves[i];
 134                 tmp[i] = acc;
 135                 if (acc > 180) {
 136                         dev_err(par->info->device,
 137                                 "Illegal value(s) in Grayscale Lookup Table. At index=%d : %d, the accumulated value has exceeded 180\n",
 138                                 i, acc);
 139                         return -EINVAL;
 140                 }
 141         }
 142 
 143         write_reg(par, 0xB8,
 144                   tmp[0],  tmp[1],  tmp[2],  tmp[3],
 145                   tmp[4],  tmp[5],  tmp[6],  tmp[7],
 146                   tmp[8],  tmp[9],  tmp[10], tmp[11],
 147                   tmp[12], tmp[13], tmp[14], tmp[15],
 148                   tmp[16], tmp[17], tmp[18], tmp[19],
 149                   tmp[20], tmp[21], tmp[22], tmp[23],
 150                   tmp[24], tmp[25], tmp[26], tmp[27],
 151                   tmp[28], tmp[29], tmp[30], tmp[31],
 152                   tmp[32], tmp[33], tmp[34], tmp[35],
 153                   tmp[36], tmp[37], tmp[38], tmp[39],
 154                   tmp[40], tmp[41], tmp[42], tmp[43],
 155                   tmp[44], tmp[45], tmp[46], tmp[47],
 156                   tmp[48], tmp[49], tmp[50], tmp[51],
 157                   tmp[52], tmp[53], tmp[54], tmp[55],
 158                   tmp[56], tmp[57], tmp[58], tmp[59],
 159                   tmp[60], tmp[61], tmp[62]);
 160 
 161         return 0;
 162 }
 163 
 164 static int blank(struct fbtft_par *par, bool on)
 165 {
 166         fbtft_par_dbg(DEBUG_BLANK, par, "(%s=%s)\n",
 167                       __func__, on ? "true" : "false");
 168         if (on)
 169                 write_reg(par, 0xAE);
 170         else
 171                 write_reg(par, 0xAF);
 172         return 0;
 173 }
 174 
 175 static struct fbtft_display display = {
 176         .regwidth = 8,
 177         .width = WIDTH,
 178         .height = HEIGHT,
 179         .gamma_num = GAMMA_NUM,
 180         .gamma_len = GAMMA_LEN,
 181         .gamma = DEFAULT_GAMMA,
 182         .fbtftops = {
 183                 .init_display = init_display,
 184                 .set_addr_win = set_addr_win,
 185                 .set_var = set_var,
 186                 .set_gamma = set_gamma,
 187                 .blank = blank,
 188         },
 189 };
 190 
 191 #ifdef CONFIG_FB_BACKLIGHT
 192 static int update_onboard_backlight(struct backlight_device *bd)
 193 {
 194         struct fbtft_par *par = bl_get_data(bd);
 195         bool on;
 196 
 197         fbtft_par_dbg(DEBUG_BACKLIGHT, par,
 198                       "%s: power=%d, fb_blank=%d\n",
 199                       __func__, bd->props.power, bd->props.fb_blank);
 200 
 201         on = (bd->props.power == FB_BLANK_UNBLANK) &&
 202              (bd->props.fb_blank == FB_BLANK_UNBLANK);
 203         /* Onboard backlight connected to GPIO0 on SSD1351, GPIO1 unused */
 204         write_reg(par, 0xB5, on ? 0x03 : 0x02);
 205 
 206         return 0;
 207 }
 208 
 209 static const struct backlight_ops bl_ops = {
 210         .update_status = update_onboard_backlight,
 211 };
 212 
 213 static void register_onboard_backlight(struct fbtft_par *par)
 214 {
 215         struct backlight_device *bd;
 216         struct backlight_properties bl_props = { 0, };
 217 
 218         bl_props.type = BACKLIGHT_RAW;
 219         bl_props.power = FB_BLANK_POWERDOWN;
 220 
 221         bd = backlight_device_register(dev_driver_string(par->info->device),
 222                                        par->info->device, par, &bl_ops,
 223                                        &bl_props);
 224         if (IS_ERR(bd)) {
 225                 dev_err(par->info->device,
 226                         "cannot register backlight device (%ld)\n",
 227                         PTR_ERR(bd));
 228                 return;
 229         }
 230         par->info->bl_dev = bd;
 231 
 232         if (!par->fbtftops.unregister_backlight)
 233                 par->fbtftops.unregister_backlight = fbtft_unregister_backlight;
 234 }
 235 #else
 236 static void register_onboard_backlight(struct fbtft_par *par) { };
 237 #endif
 238 
 239 FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1351", &display);
 240 
 241 MODULE_ALIAS("spi:" DRVNAME);
 242 MODULE_ALIAS("platform:" DRVNAME);
 243 MODULE_ALIAS("spi:ssd1351");
 244 MODULE_ALIAS("platform:ssd1351");
 245 
 246 MODULE_DESCRIPTION("SSD1351 OLED Driver");
 247 MODULE_AUTHOR("James Davies");
 248 MODULE_LICENSE("GPL");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/staging/fbtft/fb_ssd1351.c

DEFINITIONS
