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