--- /dev/null
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/gpio.h>
+#include <linux/spi/spi.h>
+#include <linux/delay.h>
+
+#include "fbtft.h"
+
+#define DRVNAME "fb_ssd1331"
+#define WIDTH 96
+#define HEIGHT 64
+#define GAMMA_NUM 1
+#define GAMMA_LEN 63
+#define DEFAULT_GAMMA "0 2 2 2 2 2 2 2 " \
+ "2 2 2 2 2 2 2 2 " \
+ "2 2 2 2 2 2 2 2 " \
+ "2 2 2 2 2 2 2 2 " \
+ "2 2 2 2 2 2 2 2 " \
+ "2 2 2 2 2 2 2 2 " \
+ "2 2 2 2 2 2 2 2 " \
+ "2 2 2 2 2 2 2" \
+
+static int init_display(struct fbtft_par *par)
+{
+ fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
+
+ par->fbtftops.reset(par);
+
+ write_reg(par, 0xae); /* Display Off */
+ write_reg(par, 0xa0, 0x70 | (par->bgr << 2)); /* Set Colour Depth */
+ write_reg(par, 0x72); // RGB colour
+ write_reg(par, 0xa1, 0x00); /* Set Display Start Line */
+ write_reg(par, 0xa2, 0x00); /* Set Display Offset */
+ write_reg(par, 0xa4); /* NORMALDISPLAY */
+ write_reg(par, 0xa8, 0x3f); // Set multiplex
+ write_reg(par, 0xad, 0x8e); // Set master
+ // write_reg(par, 0xb0, 0x0b); // Set power mode
+ write_reg(par, 0xb1, 0x31); // Precharge
+ write_reg(par, 0xb3, 0xf0); // Clock div
+ write_reg(par, 0x8a, 0x64); // Precharge A
+ write_reg(par, 0x8b, 0x78); // Precharge B
+ write_reg(par, 0x8c, 0x64); // Precharge C
+ write_reg(par, 0xbb, 0x3a); // Precharge level
+ write_reg(par, 0xbe, 0x3e); // vcomh
+ write_reg(par, 0x87, 0x06); // Master current
+ write_reg(par, 0x81, 0x91); // Contrast A
+ write_reg(par, 0x82, 0x50); // Contrast B
+ write_reg(par, 0x83, 0x7d); // Contrast C
+ write_reg(par, 0xaf); /* Set Sleep Mode Display On */
+
+ return 0;
+}
+
+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, 0x15, xs, xe);
+ write_reg(par, 0x75, ys, ye);
+}
+
+static void write_reg8_bus8(struct fbtft_par *par, int len, ...)
+{
+ va_list args;
+ int i, ret;
+ u8 *buf = (u8 *)par->buf;
+
+ if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {
+ va_start(args, len);
+ for (i = 0; i < len; i++) {
+ buf[i] = (u8)va_arg(args, unsigned int);
+ }
+ va_end(args);
+ fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par, par->info->device, u8, buf, len, "%s: ", __func__);
+ }
+
+ va_start(args, len);
+
+ *buf = (u8)va_arg(args, unsigned int);
+ if (par->gpio.dc != -1)
+ gpio_set_value(par->gpio.dc, 0);
+ ret = par->fbtftops.write(par, par->buf, sizeof(u8));
+ if (ret < 0) {
+ va_end(args);
+ dev_err(par->info->device, "%s: write() failed and returned %d\n", __func__, ret);
+ return;
+ }
+ len--;
+
+ if (len) {
+ i = len;
+ while (i--) {
+ *buf++ = (u8)va_arg(args, unsigned int);
+ }
+ ret = par->fbtftops.write(par, par->buf, len * (sizeof(u8)));
+ if (ret < 0) {
+ va_end(args);
+ dev_err(par->info->device, "%s: write() failed and returned %d\n", __func__, ret);
+ return;
+ }
+ }
+ if (par->gpio.dc != -1)
+ gpio_set_value(par->gpio.dc, 1);
+ va_end(args);
+}
+
+/*
+ Grayscale Lookup Table
+ GS1 - GS63
+ The driver Gamma curve contains the relative values between the entries
+ in the Lookup table.
+
+ From datasheet:
+ 8.8 Gray Scale Decoder
+
+ there are total 180 Gamma Settings (Setting 0 to Setting 180)
+ available for the Gray Scale table.
+
+ The gray scale is defined in incremental way, with reference
+ to the length of previous table entry:
+ Setting of GS1 has to be >= 0
+ Setting of GS2 has to be > Setting of GS1 +1
+ Setting of GS3 has to be > Setting of GS2 +1
+ :
+ Setting of GS63 has to be > Setting of GS62 +1
+
+
+*/
+static int set_gamma(struct fbtft_par *par, unsigned long *curves)
+{
+ unsigned long tmp[GAMMA_NUM * GAMMA_LEN];
+ int i, acc = 0;
+
+ fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
+
+ for (i = 0; i < 63; i++) {
+ if (i > 0 && curves[i] < 2) {
+ dev_err(par->info->device,
+ "Illegal value in Grayscale Lookup Table at index %d. " \
+ "Must be greater than 1\n", i);
+ return -EINVAL;
+ }
+ acc += curves[i];
+ tmp[i] = acc;
+ if (acc > 180) {
+ dev_err(par->info->device,
+ "Illegal value(s) in Grayscale Lookup Table. " \
+ "At index=%d, the accumulated value has exceeded 180\n", i);
+ return -EINVAL;
+ }
+ }
+
+ write_reg(par, 0xB8,
+ tmp[0], tmp[1], tmp[2], tmp[3], tmp[4], tmp[5], tmp[6], tmp[7],
+ tmp[8], tmp[9], tmp[10], tmp[11], tmp[12], tmp[13], tmp[14], tmp[15],
+ tmp[16], tmp[17], tmp[18], tmp[19], tmp[20], tmp[21], tmp[22], tmp[23],
+ tmp[24], tmp[25], tmp[26], tmp[27], tmp[28], tmp[29], tmp[30], tmp[31],
+ tmp[32], tmp[33], tmp[34], tmp[35], tmp[36], tmp[37], tmp[38], tmp[39],
+ tmp[40], tmp[41], tmp[42], tmp[43], tmp[44], tmp[45], tmp[46], tmp[47],
+ tmp[48], tmp[49], tmp[50], tmp[51], tmp[52], tmp[53], tmp[54], tmp[55],
+ tmp[56], tmp[57], tmp[58], tmp[59], tmp[60], tmp[61], tmp[62]);
+
+ return 0;
+}
+
+static int blank(struct fbtft_par *par, bool on)
+{
+ fbtft_par_dbg(DEBUG_BLANK, par, "%s(blank=%s)\n",
+ __func__, on ? "true" : "false");
+ if (on)
+ write_reg(par, 0xAE);
+ else
+ write_reg(par, 0xAF);
+ return 0;
+}
+
+
+static struct fbtft_display display = {
+ .regwidth = 8,
+ .width = WIDTH,
+ .height = HEIGHT,
+ .gamma_num = GAMMA_NUM,
+ .gamma_len = GAMMA_LEN,
+ .gamma = DEFAULT_GAMMA,
+ .fbtftops = {
+ .write_register = write_reg8_bus8,
+ .init_display = init_display,
+ .set_addr_win = set_addr_win,
+ .set_gamma = set_gamma,
+ .blank = blank,
+ },
+};
+
+FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1331", &display);
+
+MODULE_ALIAS("spi:" DRVNAME);
+MODULE_ALIAS("platform:" DRVNAME);
+MODULE_ALIAS("spi:ssd1331");
+MODULE_ALIAS("platform:ssd1331");
+
+MODULE_DESCRIPTION("SSD1331 OLED Driver");
+MODULE_AUTHOR("Alec Smecher (adapted from SSD1351 by James Davies)");
+MODULE_LICENSE("GPL");