[PATCH 18/29] staging: fbtft: add fb_ssd1306 driver
Thomas Petazzoni
thomas.petazzoni at free-electrons.com
Wed Dec 31 09:11:26 UTC 2014
This commit adds the fb_ssd1306 driver from the fbtft project at
https://github.com/notro/fbtft.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
---
drivers/staging/fbtft/Kconfig | 6 +
drivers/staging/fbtft/Makefile | 1 +
drivers/staging/fbtft/fb_ssd1306.c | 229 +++++++++++++++++++++++++++++++++++++
3 files changed, 236 insertions(+)
create mode 100644 drivers/staging/fbtft/fb_ssd1306.c
diff --git a/drivers/staging/fbtft/Kconfig b/drivers/staging/fbtft/Kconfig
index 05e8571..3ae8259 100644
--- a/drivers/staging/fbtft/Kconfig
+++ b/drivers/staging/fbtft/Kconfig
@@ -103,3 +103,9 @@ config FB_TFT_SSD1289
depends on FB_TFT
help
Framebuffer support for SSD1289
+
+config FB_TFT_SSD1306
+ tristate "FB driver for the SSD1306 OLED Controller"
+ depends on FB_TFT
+ help
+ Framebuffer support for SSD1306
diff --git a/drivers/staging/fbtft/Makefile b/drivers/staging/fbtft/Makefile
index ea5fa1e..b612a4d 100644
--- a/drivers/staging/fbtft/Makefile
+++ b/drivers/staging/fbtft/Makefile
@@ -19,3 +19,4 @@ obj-$(CONFIG_FB_TFT_RA8875) += fb_ra8875.o
obj-$(CONFIG_FB_TFT_S6D02A1) += fb_s6d02a1.o
obj-$(CONFIG_FB_TFT_S6D1121) += fb_s6d1121.o
obj-$(CONFIG_FB_TFT_SSD1289) += fb_ssd1289.o
+obj-$(CONFIG_FB_TFT_SSD1306) += fb_ssd1306.o
diff --git a/drivers/staging/fbtft/fb_ssd1306.c b/drivers/staging/fbtft/fb_ssd1306.c
new file mode 100644
index 0000000..5ea195b
--- /dev/null
+++ b/drivers/staging/fbtft/fb_ssd1306.c
@@ -0,0 +1,229 @@
+/*
+ * FB driver for the SSD1306 OLED Controller
+ *
+ * Copyright (C) 2013 Noralf Tronnes
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+
+#include "fbtft.h"
+
+#define DRVNAME "fb_ssd1306"
+#define WIDTH 128
+#define HEIGHT 64
+
+
+/*
+ write_reg() caveat:
+
+ This doesn't work because D/C has to be LOW for both values:
+ write_reg(par, val1, val2);
+
+ Do it like this:
+ write_reg(par, val1);
+ write_reg(par, val2);
+*/
+
+/* Init sequence taken from the Adafruit SSD1306 Arduino library */
+static int init_display(struct fbtft_par *par)
+{
+ fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
+
+ par->fbtftops.reset(par);
+
+ if (par->gamma.curves[0] == 0) {
+ mutex_lock(&par->gamma.lock);
+ if (par->info->var.yres == 64)
+ par->gamma.curves[0] = 0xCF;
+ else
+ par->gamma.curves[0] = 0x8F;
+ mutex_unlock(&par->gamma.lock);
+ }
+
+ /* Set Display OFF */
+ write_reg(par, 0xAE);
+
+ /* Set Display Clock Divide Ratio/ Oscillator Frequency */
+ write_reg(par, 0xD5);
+ write_reg(par, 0x80);
+
+ /* Set Multiplex Ratio */
+ write_reg(par, 0xA8);
+ if (par->info->var.yres == 64)
+ write_reg(par, 0x3F);
+ else
+ write_reg(par, 0x1F);
+
+ /* Set Display Offset */
+ write_reg(par, 0xD3);
+ write_reg(par, 0x0);
+
+ /* Set Display Start Line */
+ write_reg(par, 0x40 | 0x0);
+
+ /* Charge Pump Setting */
+ write_reg(par, 0x8D);
+ /* A[2] = 1b, Enable charge pump during display on */
+ write_reg(par, 0x14);
+
+ /* Set Memory Addressing Mode */
+ write_reg(par, 0x20);
+ /* Vertical addressing mode */
+ write_reg(par, 0x01);
+
+ /*Set Segment Re-map */
+ /* 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);
+
+ /* Set COM Pins Hardware Configuration */
+ write_reg(par, 0xDA);
+ if (par->info->var.yres == 64)
+ /* 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);
+
+ /* Set VCOMH Deselect Level */
+ write_reg(par, 0xDB);
+ /* 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 */
+ write_reg(par, 0xA4);
+
+ /* Set Normal Display
+ 0 in RAM: OFF in display panel
+ 1 in RAM: ON in display panel */
+ write_reg(par, 0xA6);
+
+ /* Set Display ON */
+ write_reg(par, 0xAF);
+
+ 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);
+
+ /* Set Lower Column Start Address for Page Addressing Mode */
+ write_reg(par, 0x00 | 0x0);
+ /* Set Higher Column Start Address for Page Addressing Mode */
+ write_reg(par, 0x10 | 0x0);
+ /* Set Display Start Line */
+ write_reg(par, 0x40 | 0x0);
+}
+
+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;
+}
+
+/* Gamma is used to control Contrast */
+static int set_gamma(struct fbtft_par *par, unsigned long *curves)
+{
+ fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
+
+ /* apply mask */
+ curves[0] &= 0xFF;
+
+ /* Set Contrast Control for BANK0 */
+ write_reg(par, 0x81);
+ write_reg(par, curves[0]);
+
+ return 0;
+}
+
+static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
+{
+ u16 *vmem16 = (u16 *)par->info->screen_base;
+ u8 *buf = par->txbuf.buf;
+ int x, y, i;
+ int ret = 0;
+
+ fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s()\n", __func__);
+
+ for (x = 0; x < par->info->var.xres; x++) {
+ for (y = 0; y < par->info->var.yres/8; y++) {
+ *buf = 0x00;
+ for (i = 0; i < 8; i++)
+ *buf |= (vmem16[(y*8+i)*par->info->var.xres+x] ? 1 : 0) << i;
+ buf++;
+ }
+ }
+
+ /* Write data */
+ gpio_set_value(par->gpio.dc, 1);
+ ret = par->fbtftops.write(par, par->txbuf.buf,
+ par->info->var.xres*par->info->var.yres/8);
+ if (ret < 0)
+ dev_err(par->info->device,
+ "%s: write failed and returned: %d\n", __func__, ret);
+
+ return ret;
+}
+
+
+static struct fbtft_display display = {
+ .regwidth = 8,
+ .width = WIDTH,
+ .height = HEIGHT,
+ .gamma_num = 1,
+ .gamma_len = 1,
+ .gamma = "00",
+ .fbtftops = {
+ .write_vmem = write_vmem,
+ .init_display = init_display,
+ .set_addr_win = set_addr_win,
+ .blank = blank,
+ .set_gamma = set_gamma,
+ },
+};
+
+
+FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1306", &display);
+
+MODULE_ALIAS("spi:" DRVNAME);
+MODULE_ALIAS("platform:" DRVNAME);
+MODULE_ALIAS("spi:ssd1306");
+MODULE_ALIAS("platform:ssd1306");
+
+MODULE_DESCRIPTION("SSD1306 OLED Driver");
+MODULE_AUTHOR("Noralf Tronnes");
+MODULE_LICENSE("GPL");
--
2.1.0
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