1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * System Specific setup for PCEngines ALIX. |
4 | * At the moment this means setup of GPIO control of LEDs |
5 | * on Alix.2/3/6 boards. |
6 | * |
7 | * Copyright (C) 2008 Constantin Baranov <const@mimas.ru> |
8 | * Copyright (C) 2011 Ed Wildgoose <kernel@wildgooses.com> |
9 | * and Philip Prindeville <philipp@redfish-solutions.com> |
10 | * |
11 | * TODO: There are large similarities with leds-net5501.c |
12 | * by Alessandro Zummo <a.zummo@towertech.it> |
13 | * In the future leds-net5501.c should be migrated over to platform |
14 | */ |
15 | |
16 | #include <linux/kernel.h> |
17 | #include <linux/init.h> |
18 | #include <linux/io.h> |
19 | #include <linux/string.h> |
20 | #include <linux/moduleparam.h> |
21 | #include <linux/leds.h> |
22 | #include <linux/platform_device.h> |
23 | #include <linux/input.h> |
24 | #include <linux/gpio_keys.h> |
25 | #include <linux/gpio/machine.h> |
26 | #include <linux/dmi.h> |
27 | |
28 | #include <asm/geode.h> |
29 | |
30 | #define BIOS_SIGNATURE_TINYBIOS 0xf0000 |
31 | #define BIOS_SIGNATURE_COREBOOT 0x500 |
32 | #define BIOS_REGION_SIZE 0x10000 |
33 | |
34 | /* |
35 | * This driver is not modular, but to keep back compatibility |
36 | * with existing use cases, continuing with module_param is |
37 | * the easiest way forward. |
38 | */ |
39 | static bool force = 0; |
40 | module_param(force, bool, 0444); |
41 | /* FIXME: Award bios is not automatically detected as Alix platform */ |
42 | MODULE_PARM_DESC(force, "Force detection as ALIX.2/ALIX.3 platform" ); |
43 | |
44 | static struct gpio_keys_button alix_gpio_buttons[] = { |
45 | { |
46 | .code = KEY_RESTART, |
47 | .gpio = 24, |
48 | .active_low = 1, |
49 | .desc = "Reset button" , |
50 | .type = EV_KEY, |
51 | .wakeup = 0, |
52 | .debounce_interval = 100, |
53 | .can_disable = 0, |
54 | } |
55 | }; |
56 | static struct gpio_keys_platform_data alix_buttons_data = { |
57 | .buttons = alix_gpio_buttons, |
58 | .nbuttons = ARRAY_SIZE(alix_gpio_buttons), |
59 | .poll_interval = 20, |
60 | }; |
61 | |
62 | static struct platform_device alix_buttons_dev = { |
63 | .name = "gpio-keys-polled" , |
64 | .id = 1, |
65 | .dev = { |
66 | .platform_data = &alix_buttons_data, |
67 | } |
68 | }; |
69 | |
70 | static struct gpio_led alix_leds[] = { |
71 | { |
72 | .name = "alix:1" , |
73 | .default_trigger = "default-on" , |
74 | }, |
75 | { |
76 | .name = "alix:2" , |
77 | .default_trigger = "default-off" , |
78 | }, |
79 | { |
80 | .name = "alix:3" , |
81 | .default_trigger = "default-off" , |
82 | }, |
83 | }; |
84 | |
85 | static struct gpio_led_platform_data alix_leds_data = { |
86 | .num_leds = ARRAY_SIZE(alix_leds), |
87 | .leds = alix_leds, |
88 | }; |
89 | |
90 | static struct gpiod_lookup_table alix_leds_gpio_table = { |
91 | .dev_id = "leds-gpio" , |
92 | .table = { |
93 | /* The Geode GPIOs should be on the CS5535 companion chip */ |
94 | GPIO_LOOKUP_IDX("cs5535-gpio" , 6, NULL, 0, GPIO_ACTIVE_LOW), |
95 | GPIO_LOOKUP_IDX("cs5535-gpio" , 25, NULL, 1, GPIO_ACTIVE_LOW), |
96 | GPIO_LOOKUP_IDX("cs5535-gpio" , 27, NULL, 2, GPIO_ACTIVE_LOW), |
97 | { } |
98 | }, |
99 | }; |
100 | |
101 | static struct platform_device alix_leds_dev = { |
102 | .name = "leds-gpio" , |
103 | .id = -1, |
104 | .dev.platform_data = &alix_leds_data, |
105 | }; |
106 | |
107 | static struct platform_device *alix_devs[] __initdata = { |
108 | &alix_buttons_dev, |
109 | &alix_leds_dev, |
110 | }; |
111 | |
112 | static void __init register_alix(void) |
113 | { |
114 | /* Setup LED control through leds-gpio driver */ |
115 | gpiod_add_lookup_table(table: &alix_leds_gpio_table); |
116 | platform_add_devices(alix_devs, ARRAY_SIZE(alix_devs)); |
117 | } |
118 | |
119 | static bool __init alix_present(unsigned long bios_phys, |
120 | const char *alix_sig, |
121 | size_t alix_sig_len) |
122 | { |
123 | const size_t bios_len = BIOS_REGION_SIZE; |
124 | const char *bios_virt; |
125 | const char *scan_end; |
126 | const char *p; |
127 | char name[64]; |
128 | |
129 | if (force) { |
130 | printk(KERN_NOTICE "%s: forced to skip BIOS test, " |
131 | "assume system is ALIX.2/ALIX.3\n" , |
132 | KBUILD_MODNAME); |
133 | return true; |
134 | } |
135 | |
136 | bios_virt = phys_to_virt(address: bios_phys); |
137 | scan_end = bios_virt + bios_len - (alix_sig_len + 2); |
138 | for (p = bios_virt; p < scan_end; p++) { |
139 | const char *tail; |
140 | char *a; |
141 | |
142 | if (memcmp(p, q: alix_sig, size: alix_sig_len) != 0) |
143 | continue; |
144 | |
145 | memcpy(name, p, sizeof(name)); |
146 | |
147 | /* remove the first \0 character from string */ |
148 | a = strchr(name, '\0'); |
149 | if (a) |
150 | *a = ' '; |
151 | |
152 | /* cut the string at a newline */ |
153 | a = strchr(name, '\r'); |
154 | if (a) |
155 | *a = '\0'; |
156 | |
157 | tail = p + alix_sig_len; |
158 | if ((tail[0] == '2' || tail[0] == '3' || tail[0] == '6')) { |
159 | printk(KERN_INFO |
160 | "%s: system is recognized as \"%s\"\n" , |
161 | KBUILD_MODNAME, name); |
162 | return true; |
163 | } |
164 | } |
165 | |
166 | return false; |
167 | } |
168 | |
169 | static bool __init alix_present_dmi(void) |
170 | { |
171 | const char *vendor, *product; |
172 | |
173 | vendor = dmi_get_system_info(field: DMI_SYS_VENDOR); |
174 | if (!vendor || strcmp(vendor, "PC Engines" )) |
175 | return false; |
176 | |
177 | product = dmi_get_system_info(field: DMI_PRODUCT_NAME); |
178 | if (!product || (strcmp(product, "ALIX.2D" ) && strcmp(product, "ALIX.6" ))) |
179 | return false; |
180 | |
181 | printk(KERN_INFO "%s: system is recognized as \"%s %s\"\n" , |
182 | KBUILD_MODNAME, vendor, product); |
183 | |
184 | return true; |
185 | } |
186 | |
187 | static int __init alix_init(void) |
188 | { |
189 | const char tinybios_sig[] = "PC Engines ALIX." ; |
190 | const char coreboot_sig[] = "PC Engines\0ALIX." ; |
191 | |
192 | if (!is_geode()) |
193 | return 0; |
194 | |
195 | if (alix_present(BIOS_SIGNATURE_TINYBIOS, alix_sig: tinybios_sig, alix_sig_len: sizeof(tinybios_sig) - 1) || |
196 | alix_present(BIOS_SIGNATURE_COREBOOT, alix_sig: coreboot_sig, alix_sig_len: sizeof(coreboot_sig) - 1) || |
197 | alix_present_dmi()) |
198 | register_alix(); |
199 | |
200 | return 0; |
201 | } |
202 | device_initcall(alix_init); |
203 | |