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Hans de Goedea5464f22015-01-20 09:22:26 +01001/*
2 * Hitachi tx18d42vm LVDS LCD panel driver
3 *
4 * (C) Copyright 2015 Hans de Goede <hdegoede@redhat.com>
5 *
6 * SPDX-License-Identifier: GPL-2.0+
7 */
8
9#include <common.h>
10
11#include <asm/gpio.h>
12#include <errno.h>
13
14/*
15 * Very simple write only SPI support, this does not use the generic SPI infra
16 * because that assumes R/W SPI, requiring a MISO pin. Also the necessary glue
17 * code alone would be larger then this minimal version.
18 */
19static void lcd_panel_spi_write(int cs, int clk, int mosi,
20 unsigned int data, int bits)
21{
22 int i, offset;
23
24 gpio_direction_output(cs, 0);
25 for (i = 0; i < bits; i++) {
26 gpio_direction_output(clk, 0);
27 offset = (bits - 1) - i;
28 gpio_direction_output(mosi, (data >> offset) & 1);
29 udelay(2);
30 gpio_direction_output(clk, 1);
31 udelay(2);
32 }
33 gpio_direction_output(cs, 1);
34 udelay(2);
35}
36
37int hitachi_tx18d42vm_init(void)
38{
39 const u16 init_data[] = {
40 0x0029, /* reset */
41 0x0025, /* standby */
42 0x0840, /* enable normally black */
43 0x0430, /* enable FRC/dither */
44 0x385f, /* enter test mode(1) */
45 0x3ca4, /* enter test mode(2) */
46 0x3409, /* enable SDRRS, enlarge OE width */
47 0x4041, /* adopt 2 line / 1 dot */
48 };
49 int i, cs, clk, mosi, ret = 0;
50
51 cs = name_to_gpio(CONFIG_VIDEO_LCD_SPI_CS);
52 clk = name_to_gpio(CONFIG_VIDEO_LCD_SPI_SCLK);
53 mosi = name_to_gpio(CONFIG_VIDEO_LCD_SPI_MOSI);
54
55 if (cs == -1 || clk == -1 || mosi == 1) {
56 printf("Error tx18d42vm spi gpio config is invalid\n");
57 return -EINVAL;
58 }
59
60 if (gpio_request(cs, "tx18d42vm-spi-cs") != 0 ||
61 gpio_request(clk, "tx18d42vm-spi-clk") != 0 ||
62 gpio_request(mosi, "tx18d42vm-spi-mosi") != 0) {
63 printf("Error cannot request tx18d42vm spi gpios\n");
64 ret = -EBUSY;
65 goto out;
66 }
67
68 for (i = 0; i < ARRAY_SIZE(init_data); i++)
69 lcd_panel_spi_write(cs, clk, mosi, init_data[i], 16);
70
71 mdelay(50); /* All the tx18d42vm drivers have a delay here ? */
72
73 lcd_panel_spi_write(cs, clk, mosi, 0x00ad, 16); /* display on */
74
75out:
76 gpio_free(mosi);
77 gpio_free(clk);
78 gpio_free(cs);
79
80 return ret;
81}