staging: fbtft: add fb_ssd1351 driver
authorThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Wed, 31 Dec 2014 09:11:28 +0000 (10:11 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 18 Jan 2015 00:46:47 +0000 (16:46 -0800)
This commit adds the fb_ssd1351 driver from the fbtft project at
https://github.com/notro/fbtft.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Noralf Tronnes <notro@tronnes.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/fbtft/Kconfig
drivers/staging/fbtft/Makefile
drivers/staging/fbtft/fb_ssd1351.c [new file with mode: 0644]

index f1e4832..2ba8ef7 100644 (file)
@@ -115,3 +115,9 @@ config FB_TFT_SSD1331
        depends on FB_TFT
        help
          Framebuffer support for SSD1331
+
+config FB_TFT_SSD1351
+       tristate "FB driver for the SSD1351 LCD Controller"
+       depends on FB_TFT
+       help
+         Framebuffer support for SSD1351
index 8dffb75..7481e34 100644 (file)
@@ -21,3 +21,4 @@ obj-$(CONFIG_FB_TFT_S6D1121)     += fb_s6d1121.o
 obj-$(CONFIG_FB_TFT_SSD1289)     += fb_ssd1289.o
 obj-$(CONFIG_FB_TFT_SSD1306)     += fb_ssd1306.o
 obj-$(CONFIG_FB_TFT_SSD1331)     += fb_ssd1331.o
+obj-$(CONFIG_FB_TFT_SSD1351)     += fb_ssd1351.o
diff --git a/drivers/staging/fbtft/fb_ssd1351.c b/drivers/staging/fbtft/fb_ssd1351.c
new file mode 100644 (file)
index 0000000..062d986
--- /dev/null
@@ -0,0 +1,258 @@
+#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_ssd1351"
+#define WIDTH          128
+#define HEIGHT         128
+#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 void register_onboard_backlight(struct fbtft_par *par);
+
+static int init_display(struct fbtft_par *par)
+{
+       fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
+
+       if (par->pdata
+               && par->pdata->display.backlight == FBTFT_ONBOARD_BACKLIGHT) {
+               /* module uses onboard GPIO for panel power */
+               par->fbtftops.register_backlight = register_onboard_backlight;
+       }
+
+       par->fbtftops.reset(par);
+
+       write_reg(par, 0xfd, 0x12); /* Command Lock */
+       write_reg(par, 0xfd, 0xb1); /* Command Lock */
+       write_reg(par, 0xae); /* Display Off */
+       write_reg(par, 0xb3, 0xf1); /* Front Clock Div */
+       write_reg(par, 0xca, 0x7f); /* Set Mux Ratio */
+       write_reg(par, 0x15, 0x00, 0x7f); /* Set Column Address */
+       write_reg(par, 0x75, 0x00, 0x7f); /* Set Row Address */
+       write_reg(par, 0xa1, 0x00); /* Set Display Start Line */
+       write_reg(par, 0xa2, 0x00); /* Set Display Offset */
+       write_reg(par, 0xb5, 0x00); /* Set GPIO */
+       write_reg(par, 0xab, 0x01); /* Set Function Selection */
+       write_reg(par, 0xb1, 0x32); /* Set Phase Length */
+       write_reg(par, 0xb4, 0xa0, 0xb5, 0x55); /* Set Segment Low Voltage */
+       write_reg(par, 0xbb, 0x17); /* Set Precharge Voltage */
+       write_reg(par, 0xbe, 0x05); /* Set VComH Voltage */
+       write_reg(par, 0xc1, 0xc8, 0x80, 0xc8); /* Set Contrast */
+       write_reg(par, 0xc7, 0x0f); /* Set Master Contrast */
+       write_reg(par, 0xb6, 0x01); /* Set Second Precharge Period */
+       write_reg(par, 0xa6); /* Set Display Mode Reset */
+       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);
+       write_reg(par, 0x5c);
+}
+
+static int set_var(struct fbtft_par *par)
+{
+       unsigned remap;
+       fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
+
+       if (par->fbtftops.init_display != init_display) {
+               /* don't risk messing up register A0h */
+               fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+                       "%s: skipping since custom init_display() is used\n",
+                       __func__);
+               return 0;
+       }
+
+       remap = 0x60 | (par->bgr << 2); /* Set Colour Depth */
+
+       switch (par->info->var.rotate) {
+       case 0:
+               write_reg(par, 0xA0, remap | 0b00 | 1<<4);
+               break;
+       case 270:
+               write_reg(par, 0xA0, remap | 0b11 | 1<<4);
+               break;
+       case 180:
+               write_reg(par, 0xA0, remap | 0b10);
+               break;
+       case 90:
+               write_reg(par, 0xA0, remap | 0b01);
+               break;
+       }
+
+       return 0;
+}
+
+/*
+       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 = {
+               .init_display = init_display,
+               .set_addr_win = set_addr_win,
+               .set_var = set_var,
+               .set_gamma = set_gamma,
+               .blank = blank,
+       },
+};
+
+#ifdef CONFIG_FB_BACKLIGHT
+static int update_onboard_backlight(struct backlight_device *bd)
+{
+       struct fbtft_par *par = bl_get_data(bd);
+       bool on;
+
+       fbtft_par_dbg(DEBUG_BACKLIGHT, par,
+               "%s: power=%d, fb_blank=%d\n",
+               __func__, bd->props.power, bd->props.fb_blank);
+
+       on = (bd->props.power == FB_BLANK_UNBLANK)
+               && (bd->props.fb_blank == FB_BLANK_UNBLANK);
+       /* Onboard backlight connected to GPIO0 on SSD1351, GPIO1 unused */
+       write_reg(par, 0xB5, on ? 0x03 : 0x02);
+
+       return 0;
+}
+
+static void register_onboard_backlight(struct fbtft_par *par)
+{
+       struct backlight_device *bd;
+       struct backlight_properties bl_props = { 0, };
+       struct backlight_ops *bl_ops;
+
+       fbtft_par_dbg(DEBUG_BACKLIGHT, par, "%s()\n", __func__);
+
+       bl_ops = devm_kzalloc(par->info->device, sizeof(struct backlight_ops),
+                               GFP_KERNEL);
+       if (!bl_ops) {
+               dev_err(par->info->device,
+                       "%s: could not allocate memory for backlight operations.\n",
+                       __func__);
+               return;
+       }
+
+       bl_ops->update_status = update_onboard_backlight;
+       bl_props.type = BACKLIGHT_RAW;
+       bl_props.power = FB_BLANK_POWERDOWN;
+
+       bd = backlight_device_register(dev_driver_string(par->info->device),
+                               par->info->device, par, bl_ops, &bl_props);
+       if (IS_ERR(bd)) {
+               dev_err(par->info->device,
+                       "cannot register backlight device (%ld)\n",
+                       PTR_ERR(bd));
+               return;
+       }
+       par->info->bl_dev = bd;
+
+       if (!par->fbtftops.unregister_backlight)
+               par->fbtftops.unregister_backlight = fbtft_unregister_backlight;
+}
+#else
+static void register_onboard_backlight(struct fbtft_par *par) { };
+#endif
+
+
+FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1351", &display);
+
+MODULE_ALIAS("spi:" DRVNAME);
+MODULE_ALIAS("platform:" DRVNAME);
+MODULE_ALIAS("spi:ssd1351");
+MODULE_ALIAS("platform:ssd1351");
+
+MODULE_DESCRIPTION("SSD1351 OLED Driver");
+MODULE_AUTHOR("James Davies");
+MODULE_LICENSE("GPL");