text: /*
   * EEPROMs access control driver for display configuration EEPROMs
   * on DigsyMTC board.
   *
   * (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  #include <linux/gpio.h>
  #include <linux/init.h>
  #include <linux/platform_device.h>
  #include <linux/spi/spi.h>
  #include <linux/spi/spi_gpio.h>
  #include <linux/eeprom_93xx46.h>
  
  #define GPIO_EEPROM_CLK		216
  #define GPIO_EEPROM_CS		210
  #define GPIO_EEPROM_DI		217
  #define GPIO_EEPROM_DO		249
  #define GPIO_EEPROM_OE		255
  #define EE_SPI_BUS_NUM	1
  
  static void digsy_mtc_op_prepare(void *p)
  {
  	/* enable */
  	gpio_set_value(GPIO_EEPROM_OE, 0);
  }
  
  static void digsy_mtc_op_finish(void *p)
  {
  	/* disable */
  	gpio_set_value(GPIO_EEPROM_OE, 1);
  }
  
  struct eeprom_93xx46_platform_data digsy_mtc_eeprom_data = {
  	.flags		= EE_ADDR8,
  	.prepare	= digsy_mtc_op_prepare,
  	.finish		= digsy_mtc_op_finish,
  };
  
  static struct spi_gpio_platform_data eeprom_spi_gpio_data = {
  	.sck		= GPIO_EEPROM_CLK,
  	.mosi		= GPIO_EEPROM_DI,
  	.miso		= GPIO_EEPROM_DO,
  	.num_chipselect	= 1,
  };
  
  static struct platform_device digsy_mtc_eeprom = {
  	.name	= "spi_gpio",
  	.id	= EE_SPI_BUS_NUM,
  	.dev	= {
  		.platform_data	= &eeprom_spi_gpio_data,
  	},
  };
  
  static struct spi_board_info digsy_mtc_eeprom_info[] __initdata = {
  	{
  		.modalias		= "93xx46",
  		.max_speed_hz		= 1000000,
  		.bus_num		= EE_SPI_BUS_NUM,
  		.chip_select		= 0,
  		.mode			= SPI_MODE_0,
  		.controller_data	= (void *)GPIO_EEPROM_CS,
  		.platform_data		= &digsy_mtc_eeprom_data,
  	},
  };
  
  static int __init digsy_mtc_eeprom_devices_init(void)
  {
  	int ret;
  
  	ret = gpio_request_one(GPIO_EEPROM_OE, GPIOF_OUT_INIT_HIGH,
  				"93xx46 EEPROMs OE");
  	if (ret) {
  		pr_err("can't request gpio %d\n", GPIO_EEPROM_OE);
  		return ret;
  	}
  	spi_register_board_info(digsy_mtc_eeprom_info,
  				ARRAY_SIZE(digsy_mtc_eeprom_info));
  	return platform_device_register(&digsy_mtc_eeprom);
  }
  device_initcall(digsy_mtc_eeprom_devices_init);
  