staging: fbtft: add fb_ra8875 driver

This commit adds the fb_ra8875 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

@@ -79,3 +79,9 @@ config FB_TFT_PCD8544
 	depends on FB_TFT
 	help
 	  Generic Framebuffer support for PCD8544
+
+config FB_TFT_RA8875
+        tristate "FB driver for the RA8875 LCD Controller"
+        depends on FB_TFT
+	help
+	  Generic Framebuffer support for RA8875

drivers/staging/fbtft/Makefile

@@ -15,3 +15,4 @@ obj-$(CONFIG_FB_TFT_ILI9341)     += fb_ili9341.o
 obj-$(CONFIG_FB_TFT_ILI9481)     += fb_ili9481.o
 obj-$(CONFIG_FB_TFT_ILI9486)     += fb_ili9486.o
 obj-$(CONFIG_FB_TFT_PCD8544)     += fb_pcd8544.o
+obj-$(CONFIG_FB_TFT_RA8875)      += fb_ra8875.o

drivers/staging/fbtft/fb_ra8875.c

+/******************************************************************************
+
+  ProjectName: FBTFT driver                       ***** *****
+	       for the RA8875 LCD Controller     *     *      ************
+						*   **   **   *           *
+  Copyright © by Pf@nne & NOTRO                *   *   *   *   *   ****	   *
+						*   *       *   *   *   *   *
+  Last modification by:                        *   *       *   *   ****    *
+  - Pf@nne (pf@nne-mail.de)                     *   *     *****           *
+						 *   *        *   *******
+						  *****      *   *
+  Date    : 10.06.2014                                      *   *
+  Version : V1.13                                          *****
+  Revison : 5
+
+*******************************************************************************
+ * 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/delay.h>
+
+#include <linux/gpio.h>
+#include "fbtft.h"
+
+#define DRVNAME "fb_ra8875"
+
+static int write_spi(struct fbtft_par *par, void *buf, size_t len)
+{
+	struct spi_transfer t = {
+		.tx_buf = buf,
+		.len = len,
+		.speed_hz = 1000000,
+	};
+	struct spi_message m;
+
+	fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+		"%s(len=%d): ", __func__, len);
+
+	if (!par->spi) {
+		dev_err(par->info->device,
+			"%s: par->spi is unexpectedly NULL\n", __func__);
+		return -1;
+	}
+
+	spi_message_init(&m);
+	if (par->txbuf.dma && buf == par->txbuf.buf) {
+		t.tx_dma = par->txbuf.dma;
+		m.is_dma_mapped = 1;
+	}
+	spi_message_add_tail(&t, &m);
+	return spi_sync(par->spi, &m);
+}
+
+static int init_display(struct fbtft_par *par)
+{
+	gpio_set_value(par->gpio.dc, 1);
+
+	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+		"%s()\n", __func__);
+	fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
+		"display size %dx%d\n", par->info->var.xres, par->info->var.yres);
+
+	par->fbtftops.reset(par);
+
+	if ((par->info->var.xres == 320) && (par->info->var.yres == 240)) {
+		/* PLL clock frequency */
+		write_reg(par, 0x88 , 0x0A);
+		write_reg(par, 0x89 , 0x02);
+		mdelay(10);
+		/* color deep / MCU Interface */
+		write_reg(par, 0x10 , 0x0C);
+		/* pixel clock period  */
+		write_reg(par, 0x04 , 0x03);
+		mdelay(1);
+		/* horizontal settings */
+		write_reg(par, 0x14 , 0x27);
+		write_reg(par, 0x15 , 0x00);
+		write_reg(par, 0x16 , 0x05);
+		write_reg(par, 0x17 , 0x04);
+		write_reg(par, 0x18 , 0x03);
+		/* vertical settings */
+		write_reg(par, 0x19 , 0xEF);
+		write_reg(par, 0x1A , 0x00);
+		write_reg(par, 0x1B , 0x05);
+		write_reg(par, 0x1C , 0x00);
+		write_reg(par, 0x1D , 0x0E);
+		write_reg(par, 0x1E , 0x00);
+		write_reg(par, 0x1F , 0x02);
+	} else if ((par->info->var.xres == 480) && (par->info->var.yres == 272)) {
+		/* PLL clock frequency  */
+		write_reg(par, 0x88 , 0x0A);
+		write_reg(par, 0x89 , 0x02);
+		mdelay(10);
+		/* color deep / MCU Interface */
+		write_reg(par, 0x10 , 0x0C);
+		/* pixel clock period  */
+		write_reg(par, 0x04 , 0x82);
+		mdelay(1);
+		/* horizontal settings */
+		write_reg(par, 0x14 , 0x3B);
+		write_reg(par, 0x15 , 0x00);
+		write_reg(par, 0x16 , 0x01);
+		write_reg(par, 0x17 , 0x00);
+		write_reg(par, 0x18 , 0x05);
+		/* vertical settings */
+		write_reg(par, 0x19 , 0x0F);
+		write_reg(par, 0x1A , 0x01);
+		write_reg(par, 0x1B , 0x02);
+		write_reg(par, 0x1C , 0x00);
+		write_reg(par, 0x1D , 0x07);
+		write_reg(par, 0x1E , 0x00);
+		write_reg(par, 0x1F , 0x09);
+	} else if ((par->info->var.xres == 640) && (par->info->var.yres == 480)) {
+		/* PLL clock frequency */
+		write_reg(par, 0x88 , 0x0B);
+		write_reg(par, 0x89 , 0x02);
+		mdelay(10);
+		/* color deep / MCU Interface */
+		write_reg(par, 0x10 , 0x0C);
+		/* pixel clock period */
+		write_reg(par, 0x04 , 0x01);
+		mdelay(1);
+		/* horizontal settings */
+		write_reg(par, 0x14 , 0x4F);
+		write_reg(par, 0x15 , 0x05);
+		write_reg(par, 0x16 , 0x0F);
+		write_reg(par, 0x17 , 0x01);
+		write_reg(par, 0x18 , 0x00);
+		/* vertical settings */
+		write_reg(par, 0x19 , 0xDF);
+		write_reg(par, 0x1A , 0x01);
+		write_reg(par, 0x1B , 0x0A);
+		write_reg(par, 0x1C , 0x00);
+		write_reg(par, 0x1D , 0x0E);
+		write_reg(par, 0x1E , 0x00);
+		write_reg(par, 0x1F , 0x01);
+	} else if ((par->info->var.xres == 800) && (par->info->var.yres == 480)) {
+		/* PLL clock frequency */
+		write_reg(par, 0x88 , 0x0B);
+		write_reg(par, 0x89 , 0x02);
+		mdelay(10);
+		/* color deep / MCU Interface */
+		write_reg(par, 0x10 , 0x0C);
+		/* pixel clock period */
+		write_reg(par, 0x04 , 0x81);
+		mdelay(1);
+		/* horizontal settings */
+		write_reg(par, 0x14 , 0x63);
+		write_reg(par, 0x15 , 0x03);
+		write_reg(par, 0x16 , 0x03);
+		write_reg(par, 0x17 , 0x02);
+		write_reg(par, 0x18 , 0x00);
+		/* vertical settings */
+		write_reg(par, 0x19 , 0xDF);
+		write_reg(par, 0x1A , 0x01);
+		write_reg(par, 0x1B , 0x14);
+		write_reg(par, 0x1C , 0x00);
+		write_reg(par, 0x1D , 0x06);
+		write_reg(par, 0x1E , 0x00);
+		write_reg(par, 0x1F , 0x01);
+	} else {
+		dev_err(par->info->device, "display size is not supported!!");
+		return -1;
+	}
+
+	/* PWM clock */
+	write_reg(par, 0x8a , 0x81);
+	write_reg(par, 0x8b , 0xFF);
+	mdelay(10);
+
+	/* Display ON */
+	write_reg(par, 0x01 , 0x80);
+	mdelay(10);
+
+	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_Active_Window */
+	write_reg(par, 0x30 , xs & 0x00FF);
+	write_reg(par, 0x31 , (xs & 0xFF00) >> 8);
+	write_reg(par, 0x32 , ys & 0x00FF);
+	write_reg(par, 0x33 , (ys & 0xFF00) >> 8);
+	write_reg(par, 0x34 , (xs+xe) & 0x00FF);
+	write_reg(par, 0x35 , ((xs+xe) & 0xFF00) >> 8);
+	write_reg(par, 0x36 , (ys+ye) & 0x00FF);
+	write_reg(par, 0x37 , ((ys+ye) & 0xFF00) >> 8);
+
+	/* Set_Memory_Write_Cursor */
+	write_reg(par, 0x46,  xs & 0xff);
+	write_reg(par, 0x47, (xs >> 8) & 0x03);
+	write_reg(par, 0x48,  ys & 0xff);
+	write_reg(par, 0x49, (ys >> 8) & 0x01);
+
+	write_reg(par, 0x02);
+}
+
+static void write_reg8_bus8(struct fbtft_par *par, int len, ...)
+{
+	va_list args;
+	int i, ret;
+	u8 *buf = (u8 *)par->buf;
+
+	/* slow down spi-speed for writing registers */
+	par->fbtftops.write = write_spi;
+
+	if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {
+		va_start(args, len);
+		for (i = 0; i < len; i++)
+			buf[i] = (u8)va_arg(args, unsigned int);
+		va_end(args);
+		fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par, par->info->device,
+			u8, buf, len, "%s: ", __func__);
+	}
+
+	va_start(args, len);
+	*buf++ = 0x80;
+	*buf = (u8)va_arg(args, unsigned int);
+	ret = par->fbtftops.write(par, par->buf, 2);
+	if (ret < 0) {
+		va_end(args);
+		dev_err(par->info->device, "%s: write() failed and returned %dn",
+			__func__, ret);
+		return;
+	}
+	len--;
+
+	udelay(100);
+
+	if (len) {
+		buf = (u8 *)par->buf;
+		*buf++ = 0x00;
+		i = len;
+		while (i--)
+			*buf++ = (u8)va_arg(args, unsigned int);
+
+		ret = par->fbtftops.write(par, par->buf, len + 1);
+		if (ret < 0) {
+			va_end(args);
+			dev_err(par->info->device, "%s: write() failed and returned %dn",
+				__func__, ret);
+			return;
+		}
+	}
+	va_end(args);
+
+	/* restore user spi-speed */
+	par->fbtftops.write = fbtft_write_spi;
+	udelay(100);
+}
+
+static int write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len)
+{
+	u16 *vmem16;
+	u16 *txbuf16 = (u16 *)par->txbuf.buf;
+	size_t remain;
+	size_t to_copy;
+	size_t tx_array_size;
+	int i;
+	int ret = 0;
+	size_t startbyte_size = 0;
+
+	fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
+		__func__, offset, len);
+
+	remain = len / 2;
+	vmem16 = (u16 *)(par->info->screen_base + offset);
+	tx_array_size = par->txbuf.len / 2;
+		txbuf16 = (u16 *)(par->txbuf.buf + 1);
+		tx_array_size -= 2;
+		*(u8 *)(par->txbuf.buf) = 0x00;
+		startbyte_size = 1;
+
+	while (remain) {
+		to_copy = remain > tx_array_size ? tx_array_size : remain;
+		dev_dbg(par->info->device, "    to_copy=%zu, remain=%zu\n",
+			to_copy, remain - to_copy);
+
+		for (i = 0; i < to_copy; i++)
+			txbuf16[i] = cpu_to_be16(vmem16[i]);
+
+		vmem16 = vmem16 + to_copy;
+		ret = par->fbtftops.write(par, par->txbuf.buf,
+			startbyte_size + to_copy * 2);
+		if (ret < 0)
+			return ret;
+		remain -= to_copy;
+	}
+
+	return ret;
+}
+
+static struct fbtft_display display = {
+	.regwidth = 8,
+	.fbtftops = {
+		.init_display = init_display,
+		.set_addr_win = set_addr_win,
+		.write_register = write_reg8_bus8,
+		.write_vmem = write_vmem16_bus8,
+		.write = write_spi,
+	},
+};
+FBTFT_REGISTER_DRIVER(DRVNAME, "raio,ra8875", &display);
+
+MODULE_ALIAS("spi:" DRVNAME);
+MODULE_ALIAS("platform:" DRVNAME);
+MODULE_ALIAS("spi:ra8875");
+MODULE_ALIAS("platform:ra8875");
+
+MODULE_DESCRIPTION("FB driver for the RA8875 LCD Controller");
+MODULE_AUTHOR("Pf@nne");
+MODULE_LICENSE("GPL");