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 
26 static void digsy_mtc_op_prepare(void *p)
27 {
28 	/* enable */
29 	gpio_set_value(GPIO_EEPROM_OE, 0);
30 }
31 
32 static void digsy_mtc_op_finish(void *p)
33 {
34 	/* disable */
35 	gpio_set_value(GPIO_EEPROM_OE, 1);
36 }
37 
38 struct 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 
44 static 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 
51 static 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 
59 static 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 
71 static 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 }
85 device_initcall(digsy_mtc_eeprom_devices_init);
86