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>

1 files changed, 81 insertions, 0 deletions

diff --git a/drivers/video/hitachi_tx18d42vm_lcd.c b/drivers/video/hitachi_tx18d42vm_lcd.c
new file mode 100644
index 0000000000..1ce4a8c93e
--- /dev/null
+++ b/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;
+}