1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Shared helper for ROHM PMIC power button registration
4 *
5 * Copyright 2018, 2019 ROHM Semiconductors
6 * Copyright 2026 Google LLC
7 */
8
9 #include <linux/device/devres.h>
10 #include <linux/gfp_types.h>
11 #include <linux/input.h>
12 #include <linux/mfd/core.h>
13 #include <linux/module.h>
14 #include <linux/property.h>
15 #include <linux/slab.h>
16
17 #include "rohm-pwrbutton.h"
18
19 #define GPIO_KEYS 0 /* Node corresponding to gpio-keys device itself */
20 #define PWRON_KEY 1 /* Node describing power button in gpio-keys */
21
rohm_pwrbutton_register_swnodes(const struct software_node * nodes)22 static int rohm_pwrbutton_register_swnodes(const struct software_node *nodes)
23 {
24 const struct software_node * const node_group[] = {
25 &nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL
26 };
27
28 return software_node_register_node_group(node_group);
29 }
30
rohm_pwrbutton_unregister_swnodes(void * data)31 static void rohm_pwrbutton_unregister_swnodes(void *data)
32 {
33 const struct software_node *nodes = data;
34 const struct software_node * const node_group[] = {
35 &nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL
36 };
37
38 software_node_unregister_node_group(node_group);
39 }
40
rohm_register_pwrbutton(struct device * dev,int irq,const char * name,bool wakeup,struct irq_domain * irq_domain)41 int rohm_register_pwrbutton(struct device *dev, int irq, const char *name,
42 bool wakeup, struct irq_domain *irq_domain)
43 {
44 const struct resource res[] = {
45 DEFINE_RES_IRQ_NAMED(irq, name),
46 };
47 struct mfd_cell gpio_keys_cell = {
48 .name = "gpio-keys",
49 .resources = res,
50 .num_resources = ARRAY_SIZE(res),
51 };
52 struct property_entry *parent_props;
53 struct property_entry *child_props;
54 struct software_node *nodes;
55 int n_props;
56 int ret;
57
58 if (irq <= 0)
59 return -EINVAL;
60
61 nodes = devm_kcalloc(dev, 2, sizeof(*nodes), GFP_KERNEL);
62 if (!nodes)
63 return -ENOMEM;
64
65 nodes[GPIO_KEYS].name = devm_kasprintf(dev, GFP_KERNEL, "%s-power-key", dev_name(dev));
66 if (!nodes[GPIO_KEYS].name)
67 return -ENOMEM;
68
69 parent_props = devm_kcalloc(dev, 2, sizeof(*parent_props), GFP_KERNEL);
70 if (!parent_props)
71 return -ENOMEM;
72
73 parent_props[0] = PROPERTY_ENTRY_STRING("label", name);
74 nodes[GPIO_KEYS].properties = parent_props;
75
76 n_props = 2; /* linux,code and terminator */
77 if (wakeup)
78 n_props++;
79
80 child_props = devm_kcalloc(dev, n_props, sizeof(*child_props), GFP_KERNEL);
81 if (!child_props)
82 return -ENOMEM;
83
84 child_props[0] = PROPERTY_ENTRY_U32("linux,code", KEY_POWER);
85 if (wakeup)
86 child_props[1] = PROPERTY_ENTRY_BOOL("wakeup-source");
87
88 nodes[PWRON_KEY].parent = &nodes[GPIO_KEYS];
89 nodes[PWRON_KEY].properties = child_props;
90
91 ret = rohm_pwrbutton_register_swnodes(nodes);
92 if (ret)
93 return ret;
94
95 ret = devm_add_action_or_reset(dev, rohm_pwrbutton_unregister_swnodes, nodes);
96 if (ret)
97 return ret;
98
99 gpio_keys_cell.swnode = &nodes[GPIO_KEYS];
100
101 ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, &gpio_keys_cell, 1,
102 NULL, 0, irq_domain);
103 if (ret)
104 return dev_err_probe(dev, ret, "Failed to register power-button");
105
106 return 0;
107 }
108 EXPORT_SYMBOL_GPL(rohm_register_pwrbutton);
109
110 MODULE_LICENSE("GPL");
111 MODULE_AUTHOR("Dmitry Torokhov <dmitry.torokhov@gmail.com>");
112 MODULE_DESCRIPTION("Shared helper for ROHM PMIC power button registration");
113