fb_ssd1306: add support for MikroElectronica OLED B Click

https://www.mikroe.com/oled-b-click

Author: Jason Kridner

drivers/staging/fbtft/fb_ssd1306.c

@@ -64,6 +64,8 @@ static int init_display(struct fbtft_par *par)
 		write_reg(par, 0x3F);
 	else if (par->info->var.yres == 48)
 		write_reg(par, 0x2F);
+	else if (par->info->var.yres == 39)
+		write_reg(par, 0x27);	/* https://libstock.mikroe.com/projects/download/1111/2577/1411057038_oled_b_click___e_mikroc_arm.zip */
 	else
 		write_reg(par, 0x1F);
 
@@ -81,16 +83,24 @@ static int init_display(struct fbtft_par *par)
 
 	/* Set Memory Addressing Mode */
 	write_reg(par, 0x20);
-	/* Vertical addressing mode  */
+	/* Vertical Addressing mode  */
 	write_reg(par, 0x01);
 
 	/* Set Segment Re-map */
-	/* column address 127 is mapped to SEG0 */
-	write_reg(par, 0xA0 | 0x1);
+	if (par->info->var.yres == 39)
+		/* no segment re-map */
+		write_reg(par, 0xA0 | 0x0);
+	else
+		/* column address 127 is mapped to SEG0 */
+		write_reg(par, 0xA0 | 0x1);
 
 	/* Set COM Output Scan Direction */
-	/* remapped mode. Scan from COM[N-1] to COM0 */
-	write_reg(par, 0xC8);
+	if (par->info->var.yres == 39)
+		/* no columnt re-map mode. Scan from COM0 to COM[N-1] */
+		write_reg(par, 0xC0 | 0x0);
+	else
+		/* remapped mode. Scan from COM[N-1] to COM0 */
+		write_reg(par, 0xC0 | 0x8);
 
 	/* Set COM Pins Hardware Configuration */
 	write_reg(par, 0xDA);
@@ -100,18 +110,27 @@ static int init_display(struct fbtft_par *par)
 	else if (par->info->var.yres == 48)
 		/* A[4]=1b, Alternative COM pin configuration */
 		write_reg(par, 0x12);
+	else if (par->info->var.yres == 39)
+		/* A[4]=1b, Alternative COM pin configuration */
+		write_reg(par, 0x12);
 	else
 		/* A[4]=0b, Sequential COM pin configuration */
 		write_reg(par, 0x02);
 
 	/* Set Pre-charge Period */
 	write_reg(par, 0xD9);
-	write_reg(par, 0xF1);
+	if (par->info->var.yres == 39)
+		write_reg(par, 0x25);
+	else
+		write_reg(par, 0xF1);
 
 	/* Set VCOMH Deselect Level */
 	write_reg(par, 0xDB);
-	/* according to the datasheet, this value is out of bounds */
-	write_reg(par, 0x40);
+	if (par->info->var.yres == 39)
+		write_reg(par, 0x20);
+	else
+		/* according to the datasheet, this value is out of bounds */
+		write_reg(par, 0x40);
 
 	/* Entire Display ON */
 	/* Resume to RAM content display. Output follows RAM content */
@@ -142,17 +161,35 @@ static void set_addr_win_64x48(struct fbtft_par *par)
 	write_reg(par, 0x5);
 }
 
+static void set_addr_win_96x39(struct fbtft_par *par)
+{
+	/* Set Page Address */
+	write_reg(par, 0xB0);
+
+	/* Set Column Address */
+	write_reg(par, 0x21);
+	write_reg(par, 0x00);
+	write_reg(par, 0x5F);
+
+	/* Set Page Address Range */
+	write_reg(par, 0x22);
+	write_reg(par, 0x0);
+	write_reg(par, 0x4);
+}
+
 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
 {
-	/* Set Lower Column Start Address for Page Addressing Mode */
+	/* Set Lower Column Start Address for Vertical Addressing Mode */
 	write_reg(par, 0x00 | 0x0);
-	/* Set Higher Column Start Address for Page Addressing Mode */
+	/* Set Higher Column Start Address for Vertical Addressing Mode */
 	write_reg(par, 0x10 | 0x0);
 	/* Set Display Start Line */
 	write_reg(par, 0x40 | 0x0);
 
 	if (par->info->var.xres == 64 && par->info->var.yres == 48)
 		set_addr_win_64x48(par);
+	else if (par->info->var.xres == 96 && par->info->var.yres == 39)
+		set_addr_win_96x39(par);
 }
 
 static int blank(struct fbtft_par *par, bool on)
@@ -196,11 +233,19 @@ static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
 				*buf |= (vmem16[(y * 8 + i) * xres + x] ? 1 : 0) << i;
 			buf++;
 		}
+		if (yres % 8) {
+			*buf = 0x00;
+			for (i = 0; i < (yres - (y * 8)); i++)
+				*buf |= (vmem16[(y * 8 + i) * xres + x] ? 1 : 0) << i;
+			buf++;
+			y++;
+		}
 	}
 
 	/* Write data */
 	gpio_set_value(par->gpio.dc, 1);
-	ret = par->fbtftops.write(par, par->txbuf.buf, xres * yres / 8);
+	ret = par->fbtftops.write(par, par->txbuf.buf, xres * (yres / 8 + (yres % 8 != 0)));
+	//ret = par->fbtftops.write(par, par->txbuf.buf, xres * 128 / 8);
 	if (ret < 0)
 		dev_err(par->info->device, "write failed and returned: %d\n",
 			ret);

drivers/staging/fbtft/fbtft_device.c

@@ -391,6 +391,25 @@ static struct fbtft_device_display displays[] = {
 				},
 			}
 		}
+	}, {
+		.name = "mikroe_oledb",
+		.spi = &(struct spi_board_info) {
+			.modalias = "fb_ssd1306",
+			.max_speed_hz = 16000000,
+			.mode = SPI_MODE_0,
+			.platform_data = &(struct fbtft_platform_data) {
+				.display = {
+					.width = 96,
+					.height = 39,
+					.buswidth = 8,
+				},
+				.gpios = (const struct fbtft_gpio []) {
+					{ "reset", 45 },
+					{ "dc", 110 },
+					{},
+				},
+			}
+		}
 	}, {
 		.name = "admatec_c-berry28",
 		.spi = &(struct spi_board_info) {