staging: fbtft: add fb_uc1701 driver

This commit adds the fb_uc1701 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

@@ -139,3 +139,9 @@ config FB_TFT_TLS8204
 	depends on FB_TFT
 	help
 	  Generic Framebuffer support for TLS8204
+
+config FB_TFT_UC1701
+	tristate "FB driver for the UC1701 LCD Controller"
+	depends on FB_TFT
+	help
+	  Generic Framebuffer support for UC1701

drivers/staging/fbtft/Makefile

@@ -25,3 +25,4 @@ obj-$(CONFIG_FB_TFT_SSD1351)     += fb_ssd1351.o
 obj-$(CONFIG_FB_TFT_ST7735R)     += fb_st7735r.o
 obj-$(CONFIG_FB_TFT_TINYLCD)     += fb_tinylcd.o
 obj-$(CONFIG_FB_TFT_TLS8204)     += fb_tls8204.o
+obj-$(CONFIG_FB_TFT_UC1701)      += fb_uc1701.o

drivers/staging/fbtft/fb_uc1701.c

+/*
+ * FB driver for the UC1701 LCD Controller
+ *
+ * The display is monochrome and the video memory is RGB565.
+ * Any pixel value except 0 turns the pixel on.
+ *
+ * Copyright (C) 2014 Juergen Holzmann
+ *
+ * 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/spi/spi.h>
+#include <linux/delay.h>
+
+#include "fbtft.h"
+
+#define DRVNAME	"fb_uc1701"
+#define WIDTH	  102
+#define HEIGHT	 64
+#define PAGES	  (HEIGHT/8)
+
+/* 1: Display on/off */
+#define LCD_DISPLAY_ENABLE    0xAE
+/* 2: display start line set */
+#define LCD_START_LINE	0x40
+/* 3: Page address set (lower 4 bits select one of the pages) */
+#define LCD_PAGE_ADDRESS      0xB0
+/* 4: column address */
+#define LCD_COL_ADDRESS       0x10
+/* 8: select orientation */
+#define LCD_BOTTOMVIEW	0xA0
+/* 9: inverted display */
+#define LCD_DISPLAY_INVERT    0xA6
+/* 10: show memory content or switch all pixels on */
+#define LCD_ALL_PIXEL	 0xA4
+/* 11: lcd bias set */
+#define LCD_BIAS	      0xA2
+/* 14: Reset Controller */
+#define LCD_RESET_CMD	 0xE2
+/* 15: output mode select (turns display upside-down) */
+#define LCD_SCAN_DIR	  0xC0
+/* 16: power control set */
+#define LCD_POWER_CONTROL     0x28
+/* 17: voltage regulator resistor ratio set */
+#define LCD_VOLTAGE	   0x20
+/* 18: Volume mode set */
+#define LCD_VOLUME_MODE       0x81
+/* 22: NOP command */
+#define LCD_NO_OP	     0xE3
+/* 25: advanced program control */
+#define LCD_ADV_PROG_CTRL     0xFA
+/* 25: advanced program control2 */
+#define LCD_ADV_PROG_CTRL2    0x10
+#define LCD_TEMPCOMP_HIGH     0x80
+/* column offset for normal orientation */
+#define SHIFT_ADDR_NORMAL     0
+/* column offset for bottom view orientation */
+#define SHIFT_ADDR_TOPVIEW    30
+
+
+static int init_display(struct fbtft_par *par)
+{
+	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
+
+	par->fbtftops.reset(par);
+
+	/* softreset of LCD */
+	write_reg(par, LCD_RESET_CMD);
+	mdelay(10);
+
+	/* set startpoint */
+	/* LCD_START_LINE | (pos & 0x3F) */
+	write_reg(par, LCD_START_LINE);
+
+	/* select orientation BOTTOMVIEW */
+	write_reg(par, LCD_BOTTOMVIEW | 1);
+	/* output mode select (turns display upside-down) */
+	write_reg(par, LCD_SCAN_DIR | 0x00);
+
+	/* Normal Pixel mode */
+	write_reg(par, LCD_ALL_PIXEL | 0);
+
+	/* positive display */
+	write_reg(par, LCD_DISPLAY_INVERT | 0);
+
+	/* bias 1/9 */
+	write_reg(par, LCD_BIAS | 0);
+
+	/* power control mode: all features on */
+	/* LCD_POWER_CONTROL | (val&0x07) */
+	write_reg(par, LCD_POWER_CONTROL | 0x07);
+
+	/* set voltage regulator R/R */
+	/* LCD_VOLTAGE | (val&0x07) */
+	write_reg(par, LCD_VOLTAGE | 0x07);
+
+	/* volume mode set */
+	/* LCD_VOLUME_MODE,val&0x3f,LCD_NO_OP */
+	write_reg(par, LCD_VOLUME_MODE);
+	/* LCD_VOLUME_MODE,val&0x3f,LCD_NO_OP */
+	write_reg(par, 0x09);
+	/* ???? */
+	/* LCD_VOLUME_MODE,val&0x3f,LCD_NO_OP */
+	write_reg(par, LCD_NO_OP);
+
+	/* advanced program control */
+	write_reg(par, LCD_ADV_PROG_CTRL);
+	write_reg(par, LCD_ADV_PROG_CTRL2|LCD_TEMPCOMP_HIGH);
+
+	/* enable display */
+	write_reg(par, LCD_DISPLAY_ENABLE | 1);
+
+	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);
+
+	/* goto address */
+	/* LCD_PAGE_ADDRESS | ((page) & 0x1F),
+	 (((col)+SHIFT_ADDR_NORMAL) & 0x0F),
+	 LCD_COL_ADDRESS | ((((col)+SHIFT_ADDR_NORMAL)>>4) & 0x0F) */
+	write_reg(par, LCD_PAGE_ADDRESS);
+	/* LCD_PAGE_ADDRESS | ((page) & 0x1F),
+	 (((col)+SHIFT_ADDR_NORMAL) & 0x0F),
+	  LCD_COL_ADDRESS | ((((col)+SHIFT_ADDR_NORMAL)>>4) & 0x0F) */
+	write_reg(par, 0x00);
+	/* LCD_PAGE_ADDRESS | ((page) & 0x1F),
+	 (((col)+SHIFT_ADDR_NORMAL) & 0x0F),
+	  LCD_COL_ADDRESS | ((((col)+SHIFT_ADDR_NORMAL)>>4) & 0x0F) */
+	write_reg(par, LCD_COL_ADDRESS);
+}
+
+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 (y = 0; y < PAGES; y++) {
+		buf = par->txbuf.buf;
+		for (x = 0; x < WIDTH; x++) {
+			*buf = 0x00;
+			for (i = 0; i < 8; i++)
+				*buf |= (vmem16[((y*8*WIDTH)+(i*WIDTH))+x] ? 1 : 0) << i;
+			buf++;
+		}
+		/* LCD_PAGE_ADDRESS | ((page) & 0x1F),
+		 (((col)+SHIFT_ADDR_NORMAL) & 0x0F),
+		  LCD_COL_ADDRESS | ((((col)+SHIFT_ADDR_NORMAL)>>4) & 0x0F) */
+		write_reg(par, LCD_PAGE_ADDRESS|(u8)y);
+		/* LCD_PAGE_ADDRESS | ((page) & 0x1F),
+		 (((col)+SHIFT_ADDR_NORMAL) & 0x0F),
+		  LCD_COL_ADDRESS | ((((col)+SHIFT_ADDR_NORMAL)>>4) & 0x0F) */
+		write_reg(par, 0x00);
+		/* LCD_PAGE_ADDRESS | ((page) & 0x1F),
+		 (((col)+SHIFT_ADDR_NORMAL) & 0x0F),
+		  LCD_COL_ADDRESS | ((((col)+SHIFT_ADDR_NORMAL)>>4) & 0x0F) */
+		write_reg(par, LCD_COL_ADDRESS);
+		gpio_set_value(par->gpio.dc, 1);
+		ret = par->fbtftops.write(par, par->txbuf.buf, WIDTH);
+		gpio_set_value(par->gpio.dc, 0);
+	}
+
+	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,
+	.fbtftops = {
+		.init_display = init_display,
+		.set_addr_win = set_addr_win,
+		.write_vmem = write_vmem,
+	},
+	.backlight = 1,
+};
+FBTFT_REGISTER_DRIVER(DRVNAME, "UltraChip,uc1701", &display);
+
+MODULE_ALIAS("spi:" DRVNAME);
+MODULE_ALIAS("spi:uc1701");
+
+MODULE_DESCRIPTION("FB driver for the UC1701 LCD Controller");
+MODULE_AUTHOR("Juergen Holzmann");
+MODULE_LICENSE("GPL");