tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 * FIXME: this driver is used on a device-tree probed platform: it
12 * should be defined as a bit-banged SPI device and probed from the device
13 * tree and not like this with static grabbing of a few numbered GPIO
14 * lines at random.
15 *
16 * Add proper SPI and EEPROM in arch/powerpc/boot/dts/digsy_mtc.dts
17 * and delete this driver.
18 */
19
20#include <linux/gpio.h>
21#include <linux/gpio/machine.h>
22#include <linux/init.h>
23#include <linux/platform_device.h>
24#include <linux/spi/spi.h>
25#include <linux/spi/spi_gpio.h>
26#include <linux/eeprom_93xx46.h>
27
28#define GPIO_EEPROM_CLK 216
29#define GPIO_EEPROM_CS 210
30#define GPIO_EEPROM_DI 217
31#define GPIO_EEPROM_DO 249
32#define GPIO_EEPROM_OE 255
33#define EE_SPI_BUS_NUM 1
34
35static void digsy_mtc_op_prepare(void *p)
36{
37 /* enable */
38 gpio_set_value(GPIO_EEPROM_OE, 0);
39}
40
41static void digsy_mtc_op_finish(void *p)
42{
43 /* disable */
44 gpio_set_value(GPIO_EEPROM_OE, 1);
45}
46
47struct eeprom_93xx46_platform_data digsy_mtc_eeprom_data = {
48 .flags = EE_ADDR8,
49 .prepare = digsy_mtc_op_prepare,
50 .finish = digsy_mtc_op_finish,
51};
52
53static struct spi_gpio_platform_data eeprom_spi_gpio_data = {
54 .num_chipselect = 1,
55};
56
57static struct platform_device digsy_mtc_eeprom = {
58 .name = "spi_gpio",
59 .id = EE_SPI_BUS_NUM,
60 .dev = {
61 .platform_data = &eeprom_spi_gpio_data,
62 },
63};
64
65static struct gpiod_lookup_table eeprom_spi_gpiod_table = {
66 .dev_id = "spi_gpio",
67 .table = {
68 GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_CLK,
69 "sck", GPIO_ACTIVE_HIGH),
70 GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_DI,
71 "mosi", GPIO_ACTIVE_HIGH),
72 GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_DO,
73 "miso", GPIO_ACTIVE_HIGH),
74 GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_CS,
75 "cs", GPIO_ACTIVE_HIGH),
76 { },
77 },
78};
79
80static struct spi_board_info digsy_mtc_eeprom_info[] __initdata = {
81 {
82 .modalias = "93xx46",
83 .max_speed_hz = 1000000,
84 .bus_num = EE_SPI_BUS_NUM,
85 .chip_select = 0,
86 .mode = SPI_MODE_0,
87 .platform_data = &digsy_mtc_eeprom_data,
88 },
89};
90
91static int __init digsy_mtc_eeprom_devices_init(void)
92{
93 int ret;
94
95 ret = gpio_request_one(GPIO_EEPROM_OE, GPIOF_OUT_INIT_HIGH,
96 "93xx46 EEPROMs OE");
97 if (ret) {
98 pr_err("can't request gpio %d\n", GPIO_EEPROM_OE);
99 return ret;
100 }
101 gpiod_add_lookup_table(&eeprom_spi_gpiod_table);
102 spi_register_board_info(digsy_mtc_eeprom_info,
103 ARRAY_SIZE(digsy_mtc_eeprom_info));
104 return platform_device_register(&digsy_mtc_eeprom);
105}
106device_initcall(digsy_mtc_eeprom_devices_init);