/*
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* Hitachi tx18d42vm LVDS LCD panel driver
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*
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* (C) Copyright 2015 Hans de Goede <hdegoede@redhat.com>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <asm/gpio.h>
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#include <errno.h>
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/*
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* Very simple write only SPI support, this does not use the generic SPI infra
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* because that assumes R/W SPI, requiring a MISO pin. Also the necessary glue
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* code alone would be larger then this minimal version.
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*/
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static void lcd_panel_spi_write(int cs, int clk, int mosi,
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unsigned int data, int bits)
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{
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int i, offset;
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gpio_direction_output(cs, 0);
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for (i = 0; i < bits; i++) {
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gpio_direction_output(clk, 0);
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offset = (bits - 1) - i;
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gpio_direction_output(mosi, (data >> offset) & 1);
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udelay(2);
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gpio_direction_output(clk, 1);
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udelay(2);
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}
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gpio_direction_output(cs, 1);
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udelay(2);
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}
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int hitachi_tx18d42vm_init(void)
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{
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const u16 init_data[] = {
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0x0029, /* reset */
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0x0025, /* standby */
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0x0840, /* enable normally black */
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0x0430, /* enable FRC/dither */
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0x385f, /* enter test mode(1) */
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0x3ca4, /* enter test mode(2) */
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0x3409, /* enable SDRRS, enlarge OE width */
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0x4041, /* adopt 2 line / 1 dot */
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};
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int i, cs, clk, mosi, ret = 0;
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cs = name_to_gpio(CONFIG_VIDEO_LCD_SPI_CS);
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clk = name_to_gpio(CONFIG_VIDEO_LCD_SPI_SCLK);
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mosi = name_to_gpio(CONFIG_VIDEO_LCD_SPI_MOSI);
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if (cs == -1 || clk == -1 || mosi == 1) {
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printf("Error tx18d42vm spi gpio config is invalid\n");
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return -EINVAL;
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}
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if (gpio_request(cs, "tx18d42vm-spi-cs") != 0 ||
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gpio_request(clk, "tx18d42vm-spi-clk") != 0 ||
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gpio_request(mosi, "tx18d42vm-spi-mosi") != 0) {
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printf("Error cannot request tx18d42vm spi gpios\n");
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ret = -EBUSY;
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goto out;
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}
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for (i = 0; i < ARRAY_SIZE(init_data); i++)
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lcd_panel_spi_write(cs, clk, mosi, init_data[i], 16);
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mdelay(50); /* All the tx18d42vm drivers have a delay here ? */
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lcd_panel_spi_write(cs, clk, mosi, 0x00ad, 16); /* display on */
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out:
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gpio_free(mosi);
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gpio_free(clk);
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gpio_free(cs);
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return ret;
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}
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