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.h>
18#include <linux/gpio/machine.h>
19#include <linux/init.h>
20#include <linux/platform_device.h>
21#include <linux/spi/spi.h>
22#include <linux/spi/spi_gpio.h>
23#include <linux/eeprom_93xx46.h>
24
25#define GPIO_EEPROM_CLK		216
26#define GPIO_EEPROM_CS		210
27#define GPIO_EEPROM_DI		217
28#define GPIO_EEPROM_DO		249
29#define GPIO_EEPROM_OE		255
30#define EE_SPI_BUS_NUM	1
31
32static void digsy_mtc_op_prepare(void *p)
33{
34	/* enable */
35	gpio_set_value(GPIO_EEPROM_OE, 0);
36}
37
38static void digsy_mtc_op_finish(void *p)
39{
40	/* disable */
41	gpio_set_value(GPIO_EEPROM_OE, 1);
42}
43
44struct eeprom_93xx46_platform_data digsy_mtc_eeprom_data = {
45	.flags		= EE_ADDR8,
46	.prepare	= digsy_mtc_op_prepare,
47	.finish		= digsy_mtc_op_finish,
48};
49
50static struct spi_gpio_platform_data eeprom_spi_gpio_data = {
51	.num_chipselect	= 1,
52};
53
54static struct platform_device digsy_mtc_eeprom = {
55	.name	= "spi_gpio",
56	.id	= EE_SPI_BUS_NUM,
57	.dev	= {
58		.platform_data	= &eeprom_spi_gpio_data,
59	},
60};
61
62static struct gpiod_lookup_table eeprom_spi_gpiod_table = {
63	.dev_id         = "spi_gpio",
64	.table          = {
65		GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_CLK,
66			    "sck", GPIO_ACTIVE_HIGH),
67		GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_DI,
68			    "mosi", GPIO_ACTIVE_HIGH),
69		GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_DO,
70			    "miso", GPIO_ACTIVE_HIGH),
71		GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_CS,
72			    "cs", GPIO_ACTIVE_HIGH),
73		{ },
74	},
75};
76
77static struct spi_board_info digsy_mtc_eeprom_info[] __initdata = {
78	{
79		.modalias		= "93xx46",
80		.max_speed_hz		= 1000000,
81		.bus_num		= EE_SPI_BUS_NUM,
82		.chip_select		= 0,
83		.mode			= SPI_MODE_0,
84		.platform_data		= &digsy_mtc_eeprom_data,
85	},
86};
87
88static int __init digsy_mtc_eeprom_devices_init(void)
89{
90	int ret;
91
92	ret = gpio_request_one(GPIO_EEPROM_OE, GPIOF_OUT_INIT_HIGH,
93				"93xx46 EEPROMs OE");
94	if (ret) {
95		pr_err("can't request gpio %d\n", GPIO_EEPROM_OE);
96		return ret;
97	}
98	gpiod_add_lookup_table(&eeprom_spi_gpiod_table);
99	spi_register_board_info(digsy_mtc_eeprom_info,
100				ARRAY_SIZE(digsy_mtc_eeprom_info));
101	return platform_device_register(&digsy_mtc_eeprom);
102}
103device_initcall(digsy_mtc_eeprom_devices_init);
104