1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2020 Philippe Reynes <philippe.reynes@softathome.com>
4 */
5
6 #include <common.h>
7 #include <button.h>
8 #include <dm.h>
9 #include <dm/lists.h>
10 #include <dm/uclass-internal.h>
11 #include <log.h>
12 #include <asm/gpio.h>
13
14 struct button_gpio_priv {
15 struct gpio_desc gpio;
16 int linux_code;
17 };
18
button_gpio_get_state(struct udevice * dev)19 static enum button_state_t button_gpio_get_state(struct udevice *dev)
20 {
21 struct button_gpio_priv *priv = dev_get_priv(dev);
22 int ret;
23
24 if (!dm_gpio_is_valid(&priv->gpio))
25 return -EREMOTEIO;
26 ret = dm_gpio_get_value(&priv->gpio);
27 if (ret < 0)
28 return ret;
29
30 return ret ? BUTTON_ON : BUTTON_OFF;
31 }
32
button_gpio_get_code(struct udevice * dev)33 static int button_gpio_get_code(struct udevice *dev)
34 {
35 struct button_gpio_priv *priv = dev_get_priv(dev);
36 int code = priv->linux_code;
37
38 if (!code)
39 return -ENODATA;
40
41 return code;
42 }
43
button_gpio_probe(struct udevice * dev)44 static int button_gpio_probe(struct udevice *dev)
45 {
46 struct button_uc_plat *uc_plat = dev_get_uclass_plat(dev);
47 struct button_gpio_priv *priv = dev_get_priv(dev);
48 int ret;
49
50 /* Ignore the top-level button node */
51 if (!uc_plat->label)
52 return 0;
53
54 ret = gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_IN);
55 if (ret)
56 return ret;
57
58 ret = dev_read_u32(dev, "linux,code", &priv->linux_code);
59
60 return ret;
61 }
62
button_gpio_remove(struct udevice * dev)63 static int button_gpio_remove(struct udevice *dev)
64 {
65 /*
66 * The GPIO driver may have already been removed. We will need to
67 * address this more generally.
68 */
69 if (!IS_ENABLED(CONFIG_SANDBOX)) {
70 struct button_gpio_priv *priv = dev_get_priv(dev);
71
72 if (dm_gpio_is_valid(&priv->gpio))
73 dm_gpio_free(dev, &priv->gpio);
74 }
75
76 return 0;
77 }
78
button_gpio_bind(struct udevice * parent)79 static int button_gpio_bind(struct udevice *parent)
80 {
81 struct udevice *dev;
82 ofnode node;
83 int ret;
84
85 dev_for_each_subnode(node, parent) {
86 struct button_uc_plat *uc_plat;
87 const char *label;
88
89 label = ofnode_read_string(node, "label");
90 if (!label) {
91 debug("%s: node %s has no label\n", __func__,
92 ofnode_get_name(node));
93 return -EINVAL;
94 }
95 ret = device_bind_driver_to_node(parent, "button_gpio",
96 ofnode_get_name(node),
97 node, &dev);
98 if (ret)
99 return ret;
100 uc_plat = dev_get_uclass_plat(dev);
101 uc_plat->label = label;
102 }
103
104 return 0;
105 }
106
107 static const struct button_ops button_gpio_ops = {
108 .get_state = button_gpio_get_state,
109 .get_code = button_gpio_get_code,
110 };
111
112 static const struct udevice_id button_gpio_ids[] = {
113 { .compatible = "gpio-keys" },
114 { .compatible = "gpio-keys-polled" },
115 { }
116 };
117
118 U_BOOT_DRIVER(button_gpio) = {
119 .name = "button_gpio",
120 .id = UCLASS_BUTTON,
121 .of_match = button_gpio_ids,
122 .ops = &button_gpio_ops,
123 .priv_auto = sizeof(struct button_gpio_priv),
124 .bind = button_gpio_bind,
125 .probe = button_gpio_probe,
126 .remove = button_gpio_remove,
127 };
128