LXR linux/drivers/misc/eeprom/digsy_mtc

   1/*
   2 * EEPROMs access control driver for display configuration EEPROMs
   3 * on DigsyMTC board.
   4 *
   5 * (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de>
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10 */
  11
  12#include <linux/gpio.h>
  13#include <linux/init.h>
  14#include <linux/platform_device.h>
  15#include <linux/spi/spi.h>
  16#include <linux/spi/spi_gpio.h>
  17#include <linux/eeprom_93xx46.h>
  18
  19#define GPIO_EEPROM_CLK         216
  20#define GPIO_EEPROM_CS          210
  21#define GPIO_EEPROM_DI          217
  22#define GPIO_EEPROM_DO          249
  23#define GPIO_EEPROM_OE          255
  24#define EE_SPI_BUS_NUM  1
  25
  26static void digsy_mtc_op_prepare(void *p)
  27{
  28        /* enable */
  29        gpio_set_value(GPIO_EEPROM_OE, 0);
  30}
  31
  32static void digsy_mtc_op_finish(void *p)
  33{
  34        /* disable */
  35        gpio_set_value(GPIO_EEPROM_OE, 1);
  36}
  37
  38struct eeprom_93xx46_platform_data digsy_mtc_eeprom_data = {
  39        .flags          = EE_ADDR8,
  40        .prepare        = digsy_mtc_op_prepare,
  41        .finish         = digsy_mtc_op_finish,
  42};
  43
  44static struct spi_gpio_platform_data eeprom_spi_gpio_data = {
  45        .sck            = GPIO_EEPROM_CLK,
  46        .mosi           = GPIO_EEPROM_DI,
  47        .miso           = GPIO_EEPROM_DO,
  48        .num_chipselect = 1,
  49};
  50
  51static struct platform_device digsy_mtc_eeprom = {
  52        .name   = "spi_gpio",
  53        .id     = EE_SPI_BUS_NUM,
  54        .dev    = {
  55                .platform_data  = &eeprom_spi_gpio_data,
  56        },
  57};
  58
  59static struct spi_board_info digsy_mtc_eeprom_info[] __initdata = {
  60        {
  61                .modalias               = "93xx46",
  62                .max_speed_hz           = 1000000,
  63                .bus_num                = EE_SPI_BUS_NUM,
  64                .chip_select            = 0,
  65                .mode                   = SPI_MODE_0,
  66                .controller_data        = (void *)GPIO_EEPROM_CS,
  67                .platform_data          = &digsy_mtc_eeprom_data,
  68        },
  69};
  70
  71static int __init digsy_mtc_eeprom_devices_init(void)
  72{
  73        int ret;
  74
  75        ret = gpio_request_one(GPIO_EEPROM_OE, GPIOF_OUT_INIT_HIGH,
  76                                "93xx46 EEPROMs OE");
  77        if (ret) {
  78                pr_err("can't request gpio %d\n", GPIO_EEPROM_OE);
  79                return ret;
  80        }
  81        spi_register_board_info(digsy_mtc_eeprom_info,
  82                                ARRAY_SIZE(digsy_mtc_eeprom_info));
  83        return platform_device_register(&digsy_mtc_eeprom);
  84}
  85device_initcall(digsy_mtc_eeprom_devices_init);
  86