staging: fbtft: add fb_watterott driver

This commit adds the fb_watterott 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

@@ -151,3 +151,9 @@ config FB_TFT_UPD161704
 	depends on FB_TFT
 	help
 	  Generic Framebuffer support for uPD161704
+
+config FB_TFT_WATTEROTT
+	tristate "FB driver for the WATTEROTT LCD Controller"
+	depends on FB_TFT
+	help
+	  Generic Framebuffer support for WATTEROTT

drivers/staging/fbtft/Makefile

@@ -27,3 +27,4 @@ obj-$(CONFIG_FB_TFT_TINYLCD)     += fb_tinylcd.o
 obj-$(CONFIG_FB_TFT_TLS8204)     += fb_tls8204.o
 obj-$(CONFIG_FB_TFT_UC1701)      += fb_uc1701.o
 obj-$(CONFIG_FB_TFT_UPD161704)   += fb_upd161704.o
+obj-$(CONFIG_FB_TFT_WATTEROTT)   += fb_watterott.o

drivers/staging/fbtft/fb_watterott.c

+/*
+ * FB driver for the Watterott LCD 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_watterott"
+#define WIDTH			320
+#define HEIGHT			240
+#define FPS			5
+#define TXBUFLEN		1024
+#define DEFAULT_BRIGHTNESS	50
+
+#define CMD_VERSION		0x01
+#define CMD_LCD_LED		0x10
+#define CMD_LCD_RESET		0x11
+#define CMD_LCD_ORIENTATION	0x20
+#define CMD_LCD_DRAWIMAGE	0x27
+#define COLOR_RGB323		8
+#define COLOR_RGB332		9
+#define COLOR_RGB233		10
+#define COLOR_RGB565		16
+
+
+static short mode = 565;
+module_param(mode, short, 0);
+MODULE_PARM_DESC(mode, "RGB color transfer mode: 332, 565 (default)");
+
+static void write_reg8_bus8(struct fbtft_par *par, int len, ...)
+{
+	va_list args;
+	int i, ret;
+	u8 *buf = par->buf;
+
+	va_start(args, len);
+	for (i = 0; i < len; i++)
+		*buf++ = (u8)va_arg(args, unsigned int);
+	va_end(args);
+
+	fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par,
+		par->info->device, u8, par->buf, len, "%s: ", __func__);
+
+	ret = par->fbtftops.write(par, par->buf, len);
+	if (ret < 0) {
+		dev_err(par->info->device,
+			"%s: write() failed and returned %d\n", __func__, ret);
+		return;
+	}
+}
+
+static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
+{
+	unsigned start_line, end_line;
+	u16 *vmem16 = (u16 *)(par->info->screen_base + offset);
+	u16 *pos = par->txbuf.buf + 1;
+	u16 *buf16 = par->txbuf.buf + 10;
+	int i, j;
+	int ret = 0;
+
+	fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s()\n", __func__);
+
+	start_line = offset / par->info->fix.line_length;
+	end_line = start_line + (len / par->info->fix.line_length) - 1;
+
+	/* Set command header. pos: x, y, w, h */
+	((u8 *)par->txbuf.buf)[0] = CMD_LCD_DRAWIMAGE;
+	pos[0] = 0;
+	pos[2] = cpu_to_be16(par->info->var.xres);
+	pos[3] = cpu_to_be16(1);
+	((u8 *)par->txbuf.buf)[9] = COLOR_RGB565;
+
+	for (i = start_line; i <= end_line; i++) {
+		pos[1] = cpu_to_be16(i);
+		for (j = 0; j < par->info->var.xres; j++)
+			buf16[j] = cpu_to_be16(*vmem16++);
+		ret = par->fbtftops.write(par,
+			par->txbuf.buf, 10 + par->info->fix.line_length);
+		if (ret < 0)
+			return ret;
+		udelay(300);
+	}
+
+	return 0;
+}
+
+#define RGB565toRGB323(c) (((c&0xE000)>>8) | ((c&0600)>>6) | ((c&0x001C)>>2))
+#define RGB565toRGB332(c) (((c&0xE000)>>8) | ((c&0700)>>6) | ((c&0x0018)>>3))
+#define RGB565toRGB233(c) (((c&0xC000)>>8) | ((c&0700)>>5) | ((c&0x001C)>>2))
+
+static int write_vmem_8bit(struct fbtft_par *par, size_t offset, size_t len)
+{
+	unsigned start_line, end_line;
+	u16 *vmem16 = (u16 *)(par->info->screen_base + offset);
+	u16 *pos = par->txbuf.buf + 1;
+	u8 *buf8 = par->txbuf.buf + 10;
+	int i, j;
+	int ret = 0;
+
+	fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s()\n", __func__);
+
+	start_line = offset / par->info->fix.line_length;
+	end_line = start_line + (len / par->info->fix.line_length) - 1;
+
+	/* Set command header. pos: x, y, w, h */
+	((u8 *)par->txbuf.buf)[0] = CMD_LCD_DRAWIMAGE;
+	pos[0] = 0;
+	pos[2] = cpu_to_be16(par->info->var.xres);
+	pos[3] = cpu_to_be16(1);
+	((u8 *)par->txbuf.buf)[9] = COLOR_RGB332;
+
+	for (i = start_line; i <= end_line; i++) {
+		pos[1] = cpu_to_be16(i);
+		for (j = 0; j < par->info->var.xres; j++) {
+			buf8[j] = RGB565toRGB332(*vmem16);
+			vmem16++;
+		}
+		ret = par->fbtftops.write(par,
+			par->txbuf.buf, 10 + par->info->var.xres);
+		if (ret < 0)
+			return ret;
+		udelay(700);
+	}
+
+	return 0;
+}
+
+static unsigned firmware_version(struct fbtft_par *par)
+{
+	u8 rxbuf[4] = {0, };
+
+	write_reg(par, CMD_VERSION);
+	par->fbtftops.read(par, rxbuf, 4);
+	if (rxbuf[1] != '.')
+		return 0;
+
+	return (rxbuf[0] - '0') << 8 | (rxbuf[2] - '0') << 4 | (rxbuf[3] - '0');
+}
+
+static int init_display(struct fbtft_par *par)
+{
+	int ret;
+	unsigned version;
+	u8 save_mode;
+
+	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
+
+	/* enable SPI interface by having CS and MOSI low during reset */
+	save_mode = par->spi->mode;
+	par->spi->mode |= SPI_CS_HIGH;
+	ret = par->spi->master->setup(par->spi); /* set CS inactive low */
+	if (ret) {
+		dev_err(par->info->device, "Could not set SPI_CS_HIGH\n");
+		return ret;
+	}
+	write_reg(par, 0x00); /* make sure mode is set */
+
+	mdelay(50);
+	par->fbtftops.reset(par);
+	mdelay(1000);
+	par->spi->mode = save_mode;
+	ret = par->spi->master->setup(par->spi);
+	if (ret) {
+		dev_err(par->info->device, "Could not restore SPI mode\n");
+		return ret;
+	}
+	write_reg(par, 0x00);
+
+	version = firmware_version(par);
+	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "Firmware version: %x.%02x\n",
+						version >> 8, version & 0xFF);
+
+	if (mode == 332)
+		par->fbtftops.write_vmem = write_vmem_8bit;
+	return 0;
+}
+
+static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
+{
+	/* not used on this controller */
+}
+
+static int set_var(struct fbtft_par *par)
+{
+	u8 rotate;
+
+	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
+
+	/* this controller rotates clock wise */
+	switch (par->info->var.rotate) {
+	case 90:
+		rotate = 27;
+		break;
+	case 180:
+		rotate = 18;
+		break;
+	case 270:
+		rotate = 9;
+		break;
+	default:
+		rotate = 0;
+	}
+	write_reg(par, CMD_LCD_ORIENTATION, rotate);
+
+	return 0;
+}
+
+static int verify_gpios(struct fbtft_par *par)
+{
+	if (par->gpio.reset < 0) {
+		dev_err(par->info->device, "Missing 'reset' gpio. Aborting.\n");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+#ifdef CONFIG_FB_BACKLIGHT
+static int backlight_chip_update_status(struct backlight_device *bd)
+{
+	struct fbtft_par *par = bl_get_data(bd);
+	int brightness = bd->props.brightness;
+
+	fbtft_par_dbg(DEBUG_BACKLIGHT, par,
+		"%s: brightness=%d, power=%d, fb_blank=%d\n",
+		__func__, bd->props.brightness, bd->props.power,
+		bd->props.fb_blank);
+
+	if (bd->props.power != FB_BLANK_UNBLANK)
+		brightness = 0;
+
+	if (bd->props.fb_blank != FB_BLANK_UNBLANK)
+		brightness = 0;
+
+	write_reg(par, CMD_LCD_LED, brightness);
+
+	return 0;
+}
+
+static void register_chip_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 = backlight_chip_update_status;
+	bl_props.type = BACKLIGHT_RAW;
+	bl_props.power = FB_BLANK_POWERDOWN;
+	bl_props.max_brightness = 100;
+	bl_props.brightness = DEFAULT_BRIGHTNESS;
+
+	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
+#define register_chip_backlight NULL
+#endif
+
+
+static struct fbtft_display display = {
+	.regwidth = 8,
+	.buswidth = 8,
+	.width = WIDTH,
+	.height = HEIGHT,
+	.fps = FPS,
+	.txbuflen = TXBUFLEN,
+	.fbtftops = {
+		.write_register = write_reg8_bus8,
+		.write_vmem = write_vmem,
+		.init_display = init_display,
+		.set_addr_win = set_addr_win,
+		.set_var = set_var,
+		.verify_gpios = verify_gpios,
+		.register_backlight = register_chip_backlight,
+	},
+};
+FBTFT_REGISTER_DRIVER(DRVNAME, "watterott,openlcd", &display);
+
+MODULE_ALIAS("spi:" DRVNAME);
+
+MODULE_DESCRIPTION("FB driver for the Watterott LCD Controller");
+MODULE_AUTHOR("Noralf Tronnes");
+MODULE_LICENSE("GPL");