digsy_mtc_eeprom.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * EEPROMs access control driver for display configuration EEPROMs
 4 * on DigsyMTC board.
 5 *
 6 * (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de>
 7 *
 8 * FIXME: this driver is used on a device-tree probed platform: it
 9 * should be defined as a bit-banged SPI device and probed from the device
10 * tree and not like this with static grabbing of a few numbered GPIO
11 * lines at random.
12 *
13 * Add proper SPI and EEPROM in arch/powerpc/boot/dts/digsy_mtc.dts
14 * and delete this driver.
15 */
16
17#include <linux/gpio/machine.h>
18#include <linux/init.h>
19#include <linux/platform_device.h>
20#include <linux/property.h>
21#include <linux/spi/spi.h>
22#include <linux/spi/spi_gpio.h>
23
24#define GPIO_EEPROM_CLK		216
25#define GPIO_EEPROM_CS		210
26#define GPIO_EEPROM_DI		217
27#define GPIO_EEPROM_DO		249
28#define GPIO_EEPROM_OE		255
29#define EE_SPI_BUS_NUM	1
30
31static const struct property_entry digsy_mtc_spi_properties[] = {
32	PROPERTY_ENTRY_U32("data-size", 8),
33	{ }
34};
35
36static const struct software_node digsy_mtc_spi_node = {
37	.properties = digsy_mtc_spi_properties,
38};
39
40static struct spi_gpio_platform_data eeprom_spi_gpio_data = {
41	.num_chipselect	= 1,
42};
43
44static struct platform_device digsy_mtc_eeprom = {
45	.name	= "spi_gpio",
46	.id	= EE_SPI_BUS_NUM,
47	.dev	= {
48		.platform_data	= &eeprom_spi_gpio_data,
49	},
50};
51
52static struct gpiod_lookup_table eeprom_spi_gpiod_table = {
53	.dev_id         = "spi_gpio.1",
54	.table          = {
55		GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_CLK,
56			    "sck", GPIO_ACTIVE_HIGH),
57		GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_DI,
58			    "mosi", GPIO_ACTIVE_HIGH),
59		GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_DO,
60			    "miso", GPIO_ACTIVE_HIGH),
61		GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_CS,
62			    "cs", GPIO_ACTIVE_HIGH),
63		GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_OE,
64			    "select", GPIO_ACTIVE_LOW),
65		{ },
66	},
67};
68
69static struct spi_board_info digsy_mtc_eeprom_info[] __initdata = {
70	{
71		.modalias		= "eeprom-93xx46",
72		.max_speed_hz		= 1000000,
73		.bus_num		= EE_SPI_BUS_NUM,
74		.chip_select		= 0,
75		.mode			= SPI_MODE_0,
76	},
77};
78
79static int __init digsy_mtc_eeprom_devices_init(void)
80{
81	int ret;
82
83	gpiod_add_lookup_table(&eeprom_spi_gpiod_table);
84	spi_register_board_info(digsy_mtc_eeprom_info,
85				ARRAY_SIZE(digsy_mtc_eeprom_info));
86
87	ret = device_add_software_node(&digsy_mtc_eeprom.dev, &digsy_mtc_spi_node);
88	if (ret)
89		return ret;
90
91	ret = platform_device_register(&digsy_mtc_eeprom);
92	if (ret)
93		device_remove_software_node(&digsy_mtc_eeprom.dev);
94
95	return ret;
96}
97device_initcall(digsy_mtc_eeprom_devices_init);