drivers/staging/fbtft/fb

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This source file includes following definitions.
init_display
set_addr_win
blank
set_var
write_vmem
   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * FB driver for the UltraChip UC1611 LCD controller
   4  *
   5  * The display is 4-bit grayscale (16 shades) 240x160.
   6  *
   7  * Copyright (C) 2015 Henri Chain
   8  */
   9 
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/gpio/consumer.h>
  14 #include <linux/spi/spi.h>
  15 #include <linux/delay.h>
  16 
  17 #include "fbtft.h"
  18 
  19 #define DRVNAME         "fb_uc1611"
  20 #define WIDTH           240
  21 #define HEIGHT          160
  22 #define BPP             8
  23 #define FPS             40
  24 
  25 /*
  26  * LCD voltage is a combination of ratio, gain, pot and temp
  27  *
  28  * V_LCD = V_BIAS * ratio
  29  * V_LCD = (C_V0 + C_PM × pot) * (1 + (T - 25) * temp)
  30  * C_V0 and C_PM depend on ratio and gain
  31  * T is ambient temperature
  32  */
  33 
  34 /* BR -> actual ratio: 0-3 -> 5, 10, 11, 13 */
  35 static unsigned int ratio = 2;
  36 module_param(ratio, uint, 0000);
  37 MODULE_PARM_DESC(ratio, "BR[1:0] Bias voltage ratio: 0-3 (default: 2)");
  38 
  39 static unsigned int gain = 3;
  40 module_param(gain, uint, 0000);
  41 MODULE_PARM_DESC(gain, "GN[1:0] Bias voltage gain: 0-3 (default: 3)");
  42 
  43 static unsigned int pot = 16;
  44 module_param(pot, uint, 0000);
  45 MODULE_PARM_DESC(pot, "PM[6:0] Bias voltage pot.: 0-63 (default: 16)");
  46 
  47 /* TC -> % compensation per deg C: 0-3 -> -.05, -.10, -.015, -.20 */
  48 static unsigned int temp;
  49 module_param(temp, uint, 0000);
  50 MODULE_PARM_DESC(temp, "TC[1:0] Temperature compensation: 0-3 (default: 0)");
  51 
  52 /* PC[1:0] -> LCD capacitance: 0-3 -> <20nF, 20-28 nF, 29-40 nF, 40-56 nF */
  53 static unsigned int load = 1;
  54 module_param(load, uint, 0000);
  55 MODULE_PARM_DESC(load, "PC[1:0] Panel Loading: 0-3 (default: 1)");
  56 
  57 /* PC[3:2] -> V_LCD: 0, 1, 3 -> ext., int. with ratio = 5, int. standard */
  58 static unsigned int pump = 3;
  59 module_param(pump, uint, 0000);
  60 MODULE_PARM_DESC(pump, "PC[3:2] Pump control: 0,1,3 (default: 3)");
  61 
  62 static int init_display(struct fbtft_par *par)
  63 {
  64         int ret;
  65 
  66         /* Set CS active high */
  67         par->spi->mode |= SPI_CS_HIGH;
  68         ret = spi_setup(par->spi);
  69         if (ret) {
  70                 dev_err(par->info->device, "Could not set SPI_CS_HIGH\n");
  71                 return ret;
  72         }
  73 
  74         /* Reset controller */
  75         write_reg(par, 0xE2);
  76 
  77         /* Set bias ratio */
  78         write_reg(par, 0xE8 | (ratio & 0x03));
  79 
  80         /* Set bias gain and potentiometer */
  81         write_reg(par, 0x81);
  82         write_reg(par, (gain & 0x03) << 6 | (pot & 0x3F));
  83 
  84         /* Set temperature compensation */
  85         write_reg(par, 0x24 | (temp & 0x03));
  86 
  87         /* Set panel loading */
  88         write_reg(par, 0x28 | (load & 0x03));
  89 
  90         /* Set pump control */
  91         write_reg(par, 0x2C | (pump & 0x03));
  92 
  93         /* Set inverse display */
  94         write_reg(par, 0xA6 | (0x01 & 0x01));
  95 
  96         /* Set 4-bit grayscale mode */
  97         write_reg(par, 0xD0 | (0x02 & 0x03));
  98 
  99         /* Set Display enable */
 100         write_reg(par, 0xA8 | 0x07);
 101 
 102         return 0;
 103 }
 104 
 105 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
 106 {
 107         switch (par->info->var.rotate) {
 108         case 90:
 109         case 270:
 110                 /* Set column address */
 111                 write_reg(par, ys & 0x0F);
 112                 write_reg(par, 0x10 | (ys >> 4));
 113 
 114                 /* Set page address (divide xs by 2) (not used by driver) */
 115                 write_reg(par, 0x60 | ((xs >> 1) & 0x0F));
 116                 write_reg(par, 0x70 | (xs >> 5));
 117                 break;
 118         default:
 119                 /* Set column address (not used by driver) */
 120                 write_reg(par, xs & 0x0F);
 121                 write_reg(par, 0x10 | (xs >> 4));
 122 
 123                 /* Set page address (divide ys by 2) */
 124                 write_reg(par, 0x60 | ((ys >> 1) & 0x0F));
 125                 write_reg(par, 0x70 | (ys >> 5));
 126                 break;
 127         }
 128 }
 129 
 130 static int blank(struct fbtft_par *par, bool on)
 131 {
 132         fbtft_par_dbg(DEBUG_BLANK, par, "(%s=%s)\n",
 133                       __func__, on ? "true" : "false");
 134 
 135         if (on)
 136                 write_reg(par, 0xA8 | 0x00);
 137         else
 138                 write_reg(par, 0xA8 | 0x07);
 139         return 0;
 140 }
 141 
 142 static int set_var(struct fbtft_par *par)
 143 {
 144         /* par->info->fix.visual = FB_VISUAL_PSEUDOCOLOR; */
 145         par->info->var.grayscale = 1;
 146         par->info->var.red.offset    = 0;
 147         par->info->var.red.length    = 8;
 148         par->info->var.green.offset  = 0;
 149         par->info->var.green.length  = 8;
 150         par->info->var.blue.offset   = 0;
 151         par->info->var.blue.length   = 8;
 152         par->info->var.transp.offset = 0;
 153         par->info->var.transp.length = 0;
 154 
 155         switch (par->info->var.rotate) {
 156         case 90:
 157                 /* Set RAM address control */
 158                 write_reg(par, 0x88
 159                         | (0x0 & 0x1) << 2 /* Increment positively */
 160                         | (0x1 & 0x1) << 1 /* Increment page first */
 161                         | (0x1 & 0x1));    /* Wrap around (default) */
 162 
 163                 /* Set LCD mapping */
 164                 write_reg(par, 0xC0
 165                         | (0x0 & 0x1) << 2 /* Mirror Y OFF */
 166                         | (0x0 & 0x1) << 1 /* Mirror X OFF */
 167                         | (0x0 & 0x1));    /* MS nibble last (default) */
 168                 break;
 169         case 180:
 170                 /* Set RAM address control */
 171                 write_reg(par, 0x88
 172                         | (0x0 & 0x1) << 2 /* Increment positively */
 173                         | (0x0 & 0x1) << 1 /* Increment column first */
 174                         | (0x1 & 0x1));    /* Wrap around (default) */
 175 
 176                 /* Set LCD mapping */
 177                 write_reg(par, 0xC0
 178                         | (0x1 & 0x1) << 2 /* Mirror Y ON */
 179                         | (0x0 & 0x1) << 1 /* Mirror X OFF */
 180                         | (0x0 & 0x1));    /* MS nibble last (default) */
 181                 break;
 182         case 270:
 183                 /* Set RAM address control */
 184                 write_reg(par, 0x88
 185                         | (0x0 & 0x1) << 2 /* Increment positively */
 186                         | (0x1 & 0x1) << 1 /* Increment page first */
 187                         | (0x1 & 0x1));    /* Wrap around (default) */
 188 
 189                 /* Set LCD mapping */
 190                 write_reg(par, 0xC0
 191                         | (0x1 & 0x1) << 2 /* Mirror Y ON */
 192                         | (0x1 & 0x1) << 1 /* Mirror X ON */
 193                         | (0x0 & 0x1));    /* MS nibble last (default) */
 194                 break;
 195         default:
 196                 /* Set RAM address control */
 197                 write_reg(par, 0x88
 198                         | (0x0 & 0x1) << 2 /* Increment positively */
 199                         | (0x0 & 0x1) << 1 /* Increment column first */
 200                         | (0x1 & 0x1));    /* Wrap around (default) */
 201 
 202                 /* Set LCD mapping */
 203                 write_reg(par, 0xC0
 204                         | (0x0 & 0x1) << 2 /* Mirror Y OFF */
 205                         | (0x1 & 0x1) << 1 /* Mirror X ON */
 206                         | (0x0 & 0x1));    /* MS nibble last (default) */
 207                 break;
 208         }
 209 
 210         return 0;
 211 }
 212 
 213 static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
 214 {
 215         u8 *vmem8 = (u8 *)(par->info->screen_buffer);
 216         u8 *buf8 = par->txbuf.buf;
 217         u16 *buf16 = par->txbuf.buf;
 218         int line_length = par->info->fix.line_length;
 219         int y_start = offset / line_length;
 220         int y_end = (offset + len - 1) / line_length;
 221         int x, y, i;
 222         int ret = 0;
 223 
 224         switch (par->pdata->display.buswidth) {
 225         case 8:
 226                 switch (par->info->var.rotate) {
 227                 case 90:
 228                 case 270:
 229                         i = y_start * line_length;
 230                         for (y = y_start; y <= y_end; y++) {
 231                                 for (x = 0; x < line_length; x += 2) {
 232                                         *buf8 = vmem8[i] >> 4;
 233                                         *buf8 |= vmem8[i + 1] & 0xF0;
 234                                         buf8++;
 235                                         i += 2;
 236                                 }
 237                         }
 238                         break;
 239                 default:
 240                         /* Must be even because pages are two lines */
 241                         y_start &= 0xFE;
 242                         i = y_start * line_length;
 243                         for (y = y_start; y <= y_end; y += 2) {
 244                                 for (x = 0; x < line_length; x++) {
 245                                         *buf8 = vmem8[i] >> 4;
 246                                         *buf8 |= vmem8[i + line_length] & 0xF0;
 247                                         buf8++;
 248                                         i++;
 249                                 }
 250                                 i += line_length;
 251                         }
 252                         break;
 253                 }
 254                 gpiod_set_value(par->gpio.dc, 1);
 255 
 256                 /* Write data */
 257                 ret = par->fbtftops.write(par, par->txbuf.buf, len / 2);
 258                 break;
 259         case 9:
 260                 switch (par->info->var.rotate) {
 261                 case 90:
 262                 case 270:
 263                         i = y_start * line_length;
 264                         for (y = y_start; y <= y_end; y++) {
 265                                 for (x = 0; x < line_length; x += 2) {
 266                                         *buf16 = 0x100;
 267                                         *buf16 |= vmem8[i] >> 4;
 268                                         *buf16 |= vmem8[i + 1] & 0xF0;
 269                                         buf16++;
 270                                         i += 2;
 271                                 }
 272                         }
 273                         break;
 274                 default:
 275                         /* Must be even because pages are two lines */
 276                         y_start &= 0xFE;
 277                         i = y_start * line_length;
 278                         for (y = y_start; y <= y_end; y += 2) {
 279                                 for (x = 0; x < line_length; x++) {
 280                                         *buf16 = 0x100;
 281                                         *buf16 |= vmem8[i] >> 4;
 282                                         *buf16 |= vmem8[i + line_length] & 0xF0;
 283                                         buf16++;
 284                                         i++;
 285                                 }
 286                                 i += line_length;
 287                         }
 288                         break;
 289                 }
 290 
 291                 /* Write data */
 292                 ret = par->fbtftops.write(par, par->txbuf.buf, len);
 293                 break;
 294         default:
 295                 dev_err(par->info->device, "unsupported buswidth %d\n",
 296                         par->pdata->display.buswidth);
 297         }
 298 
 299         if (ret < 0)
 300                 dev_err(par->info->device, "write failed and returned: %d\n",
 301                         ret);
 302 
 303         return ret;
 304 }
 305 
 306 static struct fbtft_display display = {
 307         .txbuflen = -1,
 308         .regwidth = 8,
 309         .width = WIDTH,
 310         .height = HEIGHT,
 311         .bpp = BPP,
 312         .fps = FPS,
 313         .fbtftops = {
 314                 .write_vmem = write_vmem,
 315                 .init_display = init_display,
 316                 .set_addr_win = set_addr_win,
 317                 .set_var = set_var,
 318                 .blank = blank,
 319         },
 320 };
 321 
 322 FBTFT_REGISTER_DRIVER(DRVNAME, "ultrachip,uc1611", &display);
 323 
 324 MODULE_ALIAS("spi:" DRVNAME);
 325 MODULE_ALIAS("platform:" DRVNAME);
 326 MODULE_ALIAS("spi:uc1611");
 327 MODULE_ALIAS("platform:uc1611");
 328 
 329 MODULE_DESCRIPTION("FB driver for the UC1611 LCD controller");
 330 MODULE_AUTHOR("Henri Chain");
 331 MODULE_LICENSE("GPL");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/staging/fbtft/fb_uc1611.c

DEFINITIONS
