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
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
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
--- /dev/null
+/*
+ * 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;
+}