1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * System Specific setup for Soekris net5501
4 * At the moment this means setup of GPIO control of LEDs and buttons
5 * on net5501 boards.
6 *
7 * Copyright (C) 2008-2009 Tower Technologies
8 * Written by Alessandro Zummo <a.zummo@towertech.it>
9 *
10 * Copyright (C) 2008 Constantin Baranov <const@mimas.ru>
11 * Copyright (C) 2011 Ed Wildgoose <kernel@wildgooses.com>
12 * and Philip Prindeville <philipp@redfish-solutions.com>
13 */
14
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/io.h>
18#include <linux/string.h>
19#include <linux/leds.h>
20#include <linux/platform_device.h>
21#include <linux/input.h>
22#include <linux/gpio_keys.h>
23#include <linux/gpio/machine.h>
24
25#include <asm/geode.h>
26
27#define BIOS_REGION_BASE 0xffff0000
28#define BIOS_REGION_SIZE 0x00010000
29
30static struct gpio_keys_button net5501_gpio_buttons[] = {
31 {
32 .code = KEY_RESTART,
33 .gpio = 24,
34 .active_low = 1,
35 .desc = "Reset button",
36 .type = EV_KEY,
37 .wakeup = 0,
38 .debounce_interval = 100,
39 .can_disable = 0,
40 }
41};
42static struct gpio_keys_platform_data net5501_buttons_data = {
43 .buttons = net5501_gpio_buttons,
44 .nbuttons = ARRAY_SIZE(net5501_gpio_buttons),
45 .poll_interval = 20,
46};
47
48static struct platform_device net5501_buttons_dev = {
49 .name = "gpio-keys-polled",
50 .id = 1,
51 .dev = {
52 .platform_data = &net5501_buttons_data,
53 }
54};
55
56static struct gpio_led net5501_leds[] = {
57 {
58 .name = "net5501:1",
59 .default_trigger = "default-on",
60 },
61};
62
63static struct gpio_led_platform_data net5501_leds_data = {
64 .num_leds = ARRAY_SIZE(net5501_leds),
65 .leds = net5501_leds,
66};
67
68static struct gpiod_lookup_table net5501_leds_gpio_table = {
69 .dev_id = "leds-gpio",
70 .table = {
71 /* The Geode GPIOs should be on the CS5535 companion chip */
72 GPIO_LOOKUP_IDX("cs5535-gpio", 6, NULL, 0, GPIO_ACTIVE_HIGH),
73 { }
74 },
75};
76
77static struct platform_device net5501_leds_dev = {
78 .name = "leds-gpio",
79 .id = -1,
80 .dev.platform_data = &net5501_leds_data,
81};
82
83static struct platform_device *net5501_devs[] __initdata = {
84 &net5501_buttons_dev,
85 &net5501_leds_dev,
86};
87
88static void __init register_net5501(void)
89{
90 /* Setup LED control through leds-gpio driver */
91 gpiod_add_lookup_table(table: &net5501_leds_gpio_table);
92 platform_add_devices(net5501_devs, ARRAY_SIZE(net5501_devs));
93}
94
95struct net5501_board {
96 u16 offset;
97 u16 len;
98 char *sig;
99};
100
101static struct net5501_board __initdata boards[] = {
102 { 0xb7b, 7, "net5501" }, /* net5501 v1.33/1.33c */
103 { 0xb1f, 7, "net5501" }, /* net5501 v1.32i */
104};
105
106static bool __init net5501_present(void)
107{
108 int i;
109 unsigned char *rombase, *bios;
110 bool found = false;
111
112 rombase = ioremap(BIOS_REGION_BASE, BIOS_REGION_SIZE - 1);
113 if (!rombase) {
114 printk(KERN_ERR "%s: failed to get rombase\n", KBUILD_MODNAME);
115 return found;
116 }
117
118 bios = rombase + 0x20; /* null terminated */
119
120 if (memcmp(p: bios, q: "comBIOS", size: 7))
121 goto unmap;
122
123 for (i = 0; i < ARRAY_SIZE(boards); i++) {
124 unsigned char *model = rombase + boards[i].offset;
125
126 if (!memcmp(p: model, q: boards[i].sig, size: boards[i].len)) {
127 printk(KERN_INFO "%s: system is recognized as \"%s\"\n",
128 KBUILD_MODNAME, model);
129
130 found = true;
131 break;
132 }
133 }
134
135unmap:
136 iounmap(addr: rombase);
137 return found;
138}
139
140static int __init net5501_init(void)
141{
142 if (!is_geode())
143 return 0;
144
145 if (!net5501_present())
146 return 0;
147
148 register_net5501();
149
150 return 0;
151}
152device_initcall(net5501_init);
153

source code of linux/arch/x86/platform/geode/net5501.c