LXR linux/drivers/staging/fbtft/fb

   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
  25static 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
  60static 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
  66static 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        gpiod_set_value(par->gpio.dc, 0);
  85        ret = par->fbtftops.write(par, par->buf, sizeof(u8));
  86        if (ret < 0) {
  87                va_end(args);
  88                dev_err(par->info->device,
  89                        "write() failed and returned %d\n", ret);
  90                return;
  91        }
  92        len--;
  93
  94        if (len) {
  95                i = len;
  96                while (i--)
  97                        *buf++ = (u8)va_arg(args, unsigned int);
  98                ret = par->fbtftops.write(par, par->buf, len * (sizeof(u8)));
  99                if (ret < 0) {
 100                        va_end(args);
 101                        dev_err(par->info->device,
 102                                "write() failed and returned %d\n", ret);
 103                        return;
 104                }
 105        }
 106        gpiod_set_value(par->gpio.dc, 1);
 107        va_end(args);
 108}
 109
 110/*
 111 * Grayscale Lookup Table
 112 * GS1 - GS63
 113 * The driver Gamma curve contains the relative values between the entries
 114 * in the Lookup table.
 115 *
 116 * From datasheet:
 117 * 8.8 Gray Scale Decoder
 118 *
 119 * there are total 180 Gamma Settings (Setting 0 to Setting 180)
 120 * available for the Gray Scale table.
 121 *
 122 * The gray scale is defined in incremental way, with reference
 123 * to the length of previous table entry:
 124 * Setting of GS1 has to be >= 0
 125 * Setting of GS2 has to be > Setting of GS1 +1
 126 * Setting of GS3 has to be > Setting of GS2 +1
 127 * :
 128 * Setting of GS63 has to be > Setting of GS62 +1
 129 *
 130 */
 131static int set_gamma(struct fbtft_par *par, u32 *curves)
 132{
 133        unsigned long tmp[GAMMA_NUM * GAMMA_LEN];
 134        int i, acc = 0;
 135
 136        for (i = 0; i < 63; i++) {
 137                if (i > 0 && curves[i] < 2) {
 138                        dev_err(par->info->device,
 139                                "Illegal value in Grayscale Lookup Table at index %d. Must be greater than 1\n",
 140                                i);
 141                        return -EINVAL;
 142                }
 143                acc += curves[i];
 144                tmp[i] = acc;
 145                if (acc > 180) {
 146                        dev_err(par->info->device,
 147                                "Illegal value(s) in Grayscale Lookup Table. At index=%d, the accumulated value has exceeded 180\n",
 148                                i);
 149                        return -EINVAL;
 150                }
 151        }
 152
 153        write_reg(par, 0xB8,
 154                  tmp[0], tmp[1], tmp[2], tmp[3], tmp[4], tmp[5], tmp[6],
 155                  tmp[7], tmp[8], tmp[9], tmp[10], tmp[11], tmp[12], tmp[13],
 156                  tmp[14], tmp[15], tmp[16], tmp[17], tmp[18], tmp[19], tmp[20],
 157                  tmp[21], tmp[22], tmp[23], tmp[24], tmp[25], tmp[26], tmp[27],
 158                  tmp[28], tmp[29], tmp[30], tmp[31], tmp[32], tmp[33], tmp[34],
 159                  tmp[35], tmp[36], tmp[37], tmp[38], tmp[39], tmp[40], tmp[41],
 160                  tmp[42], tmp[43], tmp[44], tmp[45], tmp[46], tmp[47], tmp[48],
 161                  tmp[49], tmp[50], tmp[51], tmp[52], tmp[53], tmp[54], tmp[55],
 162                  tmp[56], tmp[57], tmp[58], tmp[59], tmp[60], tmp[61],
 163                  tmp[62]);
 164
 165        return 0;
 166}
 167
 168static int blank(struct fbtft_par *par, bool on)
 169{
 170        fbtft_par_dbg(DEBUG_BLANK, par, "(%s=%s)\n",
 171                      __func__, on ? "true" : "false");
 172        if (on)
 173                write_reg(par, 0xAE);
 174        else
 175                write_reg(par, 0xAF);
 176        return 0;
 177}
 178
 179static struct fbtft_display display = {
 180        .regwidth = 8,
 181        .width = WIDTH,
 182        .height = HEIGHT,
 183        .gamma_num = GAMMA_NUM,
 184        .gamma_len = GAMMA_LEN,
 185        .gamma = DEFAULT_GAMMA,
 186        .fbtftops = {
 187                .write_register = write_reg8_bus8,
 188                .init_display = init_display,
 189                .set_addr_win = set_addr_win,
 190                .set_gamma = set_gamma,
 191                .blank = blank,
 192        },
 193};
 194
 195FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1331", &display);
 196
 197MODULE_ALIAS("spi:" DRVNAME);
 198MODULE_ALIAS("platform:" DRVNAME);
 199MODULE_ALIAS("spi:ssd1331");
 200MODULE_ALIAS("platform:ssd1331");
 201
 202MODULE_DESCRIPTION("SSD1331 OLED Driver");
 203MODULE_AUTHOR("Alec Smecher (adapted from SSD1351 by James Davies)");
 204MODULE_LICENSE("GPL");
 205