1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Shared helpers to register GPIO-connected buttons and LEDs
4 * on AMD Geode boards.
5 */
6
7 #include <linux/err.h>
8 #include <linux/gpio/machine.h>
9 #include <linux/gpio/property.h>
10 #include <linux/input.h>
11 #include <linux/leds.h>
12 #include <linux/mfd/cs5535.h>
13 #include <linux/platform_device.h>
14 #include <linux/slab.h>
15
16 #include "geode-common.h"
17
18 static const struct property_entry geode_gpio_keys_props[] = {
19 PROPERTY_ENTRY_U32("poll-interval", 20),
20 { }
21 };
22
23 static const struct software_node geode_gpio_keys_node = {
24 .name = "geode-gpio-keys",
25 .properties = geode_gpio_keys_props,
26 };
27
28 static struct software_node_ref_args geode_restart_gpio_ref;
29
30 static const struct property_entry geode_restart_key_props[] = {
31 PROPERTY_ENTRY_REF_ARRAY_LEN("gpios", &geode_restart_gpio_ref, 1),
32 PROPERTY_ENTRY_U32("linux,code", KEY_RESTART),
33 PROPERTY_ENTRY_STRING("label", "Reset button"),
34 PROPERTY_ENTRY_U32("debounce-interval", 100),
35 { }
36 };
37
38 static const struct software_node geode_restart_key_node = {
39 .parent = &geode_gpio_keys_node,
40 .properties = geode_restart_key_props,
41 };
42
43 static const struct software_node *geode_gpio_keys_swnodes[] __initconst = {
44 &geode_gpio_keys_node,
45 &geode_restart_key_node,
46 NULL
47 };
48
49 /*
50 * Creates gpio-keys-polled device for the restart key.
51 *
52 * Note that it needs to be called first, before geode_create_leds(),
53 * because it registers gpiochip software node used by both gpio-keys and
54 * leds-gpio devices.
55 */
geode_create_restart_key(unsigned int pin)56 int __init geode_create_restart_key(unsigned int pin)
57 {
58 struct platform_device_info keys_info = {
59 .name = "gpio-keys-polled",
60 .id = 1,
61 };
62 struct platform_device *pd;
63 int err;
64
65 geode_restart_gpio_ref = SOFTWARE_NODE_REFERENCE(&cs5535_gpio_swnode,
66 pin, GPIO_ACTIVE_LOW);
67
68 err = software_node_register_node_group(geode_gpio_keys_swnodes);
69 if (err) {
70 pr_err("failed to register gpio-keys software nodes: %d\n", err);
71 return err;
72 }
73
74 keys_info.fwnode = software_node_fwnode(&geode_gpio_keys_node);
75
76 pd = platform_device_register_full(&keys_info);
77 err = PTR_ERR_OR_ZERO(pd);
78 if (err) {
79 pr_err("failed to create gpio-keys device: %d\n", err);
80 software_node_unregister_node_group(geode_gpio_keys_swnodes);
81 return err;
82 }
83
84 return 0;
85 }
86
87 static const struct software_node geode_gpio_leds_node = {
88 .name = "geode-leds",
89 };
90
91 #define MAX_LEDS 3
92
geode_create_leds(const char * label,const struct geode_led * leds,unsigned int n_leds)93 int __init geode_create_leds(const char *label, const struct geode_led *leds,
94 unsigned int n_leds)
95 {
96 const struct software_node *group[MAX_LEDS + 2] = { 0 };
97 struct software_node *swnodes;
98 struct property_entry *props;
99 struct software_node_ref_args *gpio_refs;
100 struct platform_device_info led_info = {
101 .name = "leds-gpio",
102 .id = PLATFORM_DEVID_NONE,
103 };
104 struct platform_device *led_dev;
105 const char *node_name;
106 int err;
107 int i;
108
109 if (n_leds > MAX_LEDS) {
110 pr_err("%s: too many LEDs\n", __func__);
111 return -EINVAL;
112 }
113
114 swnodes = kzalloc_objs(*swnodes, n_leds);
115 if (!swnodes)
116 return -ENOMEM;
117
118 /*
119 * Each LED is represented by 3 properties: "gpios",
120 * "linux,default-trigger", and am empty terminator.
121 */
122 props = kzalloc_objs(*props, n_leds * 3);
123 if (!props) {
124 err = -ENOMEM;
125 goto err_free_swnodes;
126 }
127
128 gpio_refs = kzalloc_objs(*gpio_refs, n_leds);
129 if (!gpio_refs) {
130 err = -ENOMEM;
131 goto err_free_props;
132 }
133
134 group[0] = &geode_gpio_leds_node;
135 for (i = 0; i < n_leds; i++) {
136 node_name = kasprintf(GFP_KERNEL, "%s:%d", label, i);
137 if (!node_name) {
138 err = -ENOMEM;
139 goto err_free_names;
140 }
141
142 gpio_refs[i] = SOFTWARE_NODE_REFERENCE(&cs5535_gpio_swnode,
143 leds[i].pin,
144 GPIO_ACTIVE_LOW);
145 props[i * 3 + 0] =
146 PROPERTY_ENTRY_REF_ARRAY_LEN("gpios", &gpio_refs[i], 1);
147 props[i * 3 + 1] =
148 PROPERTY_ENTRY_STRING("linux,default-trigger",
149 leds[i].default_on ?
150 "default-on" : "default-off");
151 /* props[i * 3 + 2] is an empty terminator */
152
153 swnodes[i] = SOFTWARE_NODE(node_name, &props[i * 3],
154 &geode_gpio_leds_node);
155 group[i + 1] = &swnodes[i];
156 }
157
158 err = software_node_register_node_group(group);
159 if (err) {
160 pr_err("failed to register LED software nodes: %d\n", err);
161 goto err_free_names;
162 }
163
164 led_info.fwnode = software_node_fwnode(&geode_gpio_leds_node);
165
166 led_dev = platform_device_register_full(&led_info);
167 err = PTR_ERR_OR_ZERO(led_dev);
168 if (err) {
169 pr_err("failed to create LED device: %d\n", err);
170 goto err_unregister_group;
171 }
172
173 return 0;
174
175 err_unregister_group:
176 software_node_unregister_node_group(group);
177 err_free_names:
178 while (--i >= 0)
179 kfree(swnodes[i].name);
180 kfree(gpio_refs);
181 err_free_props:
182 kfree(props);
183 err_free_swnodes:
184 kfree(swnodes);
185 return err;
186 }
187
188 MODULE_IMPORT_NS("CS5535");
189