video: Add support for Hitachi tx18d42vm LVDS LCD panels

Add support for Hitachi tx18d42vm LVDS LCD panels, these panels have a
lcd controller which needs to be initialized over SPI, once that is
done they work like a regular LVDS panel.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Anatolij Gustschin <agust@denx.de>

drivers/video/Kconfig

@@ -36,9 +36,18 @@ config VIDEO_LCD_SSD2828_RESET
 	The reset pin of SSD2828 chip. This takes a string in the format
 	understood by 'name_to_gpio' function, e.g. PH1 for pin 1 of port H.
 
+config VIDEO_LCD_HITACHI_TX18D42VM
+	bool "Hitachi tx18d42vm LVDS LCD panel support"
+	depends on VIDEO
+	default n
+	---help---
+	Support for Hitachi tx18d42vm LVDS LCD panels, these panels have a
+	lcd controller which needs to be initialized over SPI, once that is
+	done they work like a regular LVDS panel.
+
 config VIDEO_LCD_SPI_CS
 	string "SPI CS pin for LCD related config job"
-	depends on VIDEO_LCD_SSD2828
+	depends on VIDEO_LCD_SSD2828 || VIDEO_LCD_HITACHI_TX18D42VM
 	default ""
 	---help---
 	This is one of the SPI communication pins, involved in setting up a
@@ -48,7 +57,7 @@ config VIDEO_LCD_SPI_CS
 
 config VIDEO_LCD_SPI_SCLK
 	string "SPI SCLK pin for LCD related config job"
-	depends on VIDEO_LCD_SSD2828
+	depends on VIDEO_LCD_SSD2828 || VIDEO_LCD_HITACHI_TX18D42VM
 	default ""
 	---help---
 	This is one of the SPI communication pins, involved in setting up a
@@ -58,7 +67,7 @@ config VIDEO_LCD_SPI_SCLK
 
 config VIDEO_LCD_SPI_MOSI
 	string "SPI MOSI pin for LCD related config job"
-	depends on VIDEO_LCD_SSD2828
+	depends on VIDEO_LCD_SSD2828 || VIDEO_LCD_HITACHI_TX18D42VM
 	default ""
 	---help---
 	This is one of the SPI communication pins, involved in setting up a

drivers/video/Makefile

@@ -29,6 +29,7 @@ obj-$(CONFIG_VIDEO_COREBOOT) += coreboot_fb.o
 obj-$(CONFIG_VIDEO_CT69000) += ct69000.o videomodes.o
 obj-$(CONFIG_VIDEO_DA8XX) += da8xx-fb.o videomodes.o
 obj-$(CONFIG_VIDEO_IMX25LCDC) += imx25lcdc.o videomodes.o
+obj-$(CONFIG_VIDEO_LCD_HITACHI_TX18D42VM) += hitachi_tx18d42vm_lcd.o
 obj-$(CONFIG_VIDEO_LCD_SSD2828) += ssd2828.o
 obj-$(CONFIG_VIDEO_MB862xx) += mb862xx.o videomodes.o
 obj-$(CONFIG_VIDEO_MB86R0xGDC) += mb86r0xgdc.o videomodes.o

drivers/video/hitachi_tx18d42vm_lcd.c

@@ -0,0 +1,81 @@
+/*
+ * Hitachi tx18d42vm LVDS LCD panel driver
+ *
+ * (C) Copyright 2015 Hans de Goede <hdegoede@redhat.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+
+#include <asm/gpio.h>
+#include <errno.h>
+
+/*
+ * Very simple write only SPI support, this does not use the generic SPI infra
+ * because that assumes R/W SPI, requiring a MISO pin. Also the necessary glue
+ * code alone would be larger then this minimal version.
+ */
+static void lcd_panel_spi_write(int cs, int clk, int mosi,
+				unsigned int data, int bits)
+{
+	int i, offset;
+
+	gpio_direction_output(cs, 0);
+	for (i = 0; i < bits; i++) {
+		gpio_direction_output(clk, 0);
+		offset = (bits - 1) - i;
+		gpio_direction_output(mosi, (data >> offset) & 1);
+		udelay(2);
+		gpio_direction_output(clk, 1);
+		udelay(2);
+	}
+	gpio_direction_output(cs, 1);
+	udelay(2);
+}
+
+int hitachi_tx18d42vm_init(void)
+{
+	const u16 init_data[] = {
+		0x0029,		/* reset */
+		0x0025,		/* standby */
+		0x0840,		/* enable normally black */
+		0x0430,		/* enable FRC/dither */
+		0x385f,		/* enter test mode(1) */
+		0x3ca4,		/* enter test mode(2) */
+		0x3409,		/* enable SDRRS, enlarge OE width */
+		0x4041,		/* adopt 2 line / 1 dot */
+	};
+	int i, cs, clk, mosi, ret = 0;
+
+	cs = name_to_gpio(CONFIG_VIDEO_LCD_SPI_CS);
+	clk = name_to_gpio(CONFIG_VIDEO_LCD_SPI_SCLK);
+	mosi = name_to_gpio(CONFIG_VIDEO_LCD_SPI_MOSI);
+
+	if (cs == -1 || clk == -1 || mosi == 1) {
+		printf("Error tx18d42vm spi gpio config is invalid\n");
+		return -EINVAL;
+	}
+
+	if (gpio_request(cs, "tx18d42vm-spi-cs") != 0 ||
+	    gpio_request(clk, "tx18d42vm-spi-clk") != 0 ||
+	    gpio_request(mosi, "tx18d42vm-spi-mosi") != 0) {
+		printf("Error cannot request tx18d42vm spi gpios\n");
+		ret = -EBUSY;
+		goto out;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(init_data); i++)
+		lcd_panel_spi_write(cs, clk, mosi, init_data[i], 16);
+
+	mdelay(50); /* All the tx18d42vm drivers have a delay here ? */
+
+	lcd_panel_spi_write(cs, clk, mosi, 0x00ad, 16); /* display on */
+
+out:
+	gpio_free(mosi);
+	gpio_free(clk);
+	gpio_free(cs);
+
+	return ret;
+}

drivers/video/hitachi_tx18d42vm_lcd.h

@@ -0,0 +1,9 @@
+/*
+ * Hitachi tx18d42vm LVDS LCD panel driver
+ *
+ * (C) Copyright 2015 Hans de Goede <hdegoede@redhat.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+void hitachi_tx18d42vm_init(void);