LXR uboot/drivers/video/hitachi_tx18d42vm

   1/*
   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}
  82