1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright 2019 NXP.
4 */
5
6#include <linux/err.h>
7#include <linux/device.h>
8#include <linux/firmware/imx/sci.h>
9#include <linux/init.h>
10#include <linux/input.h>
11#include <linux/interrupt.h>
12#include <linux/jiffies.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/platform_device.h>
17#include <linux/property.h>
18
19#define DEBOUNCE_TIME 30
20#define REPEAT_INTERVAL 60
21
22#define SC_IRQ_BUTTON 1
23#define SC_IRQ_GROUP_WAKE 3
24
25#define IMX_SC_MISC_FUNC_GET_BUTTON_STATUS 18
26
27struct imx_key_drv_data {
28 u32 keycode;
29 bool keystate; /* true: pressed, false: released */
30 struct delayed_work check_work;
31 struct input_dev *input;
32 struct imx_sc_ipc *key_ipc_handle;
33 struct notifier_block key_notifier;
34};
35
36struct imx_sc_msg_key {
37 struct imx_sc_rpc_msg hdr;
38 u32 state;
39};
40
41static int imx_sc_key_notify(struct notifier_block *nb,
42 unsigned long event, void *group)
43{
44 struct imx_key_drv_data *priv =
45 container_of(nb,
46 struct imx_key_drv_data,
47 key_notifier);
48
49 if ((event & SC_IRQ_BUTTON) && (*(u8 *)group == SC_IRQ_GROUP_WAKE)) {
50 schedule_delayed_work(dwork: &priv->check_work,
51 delay: msecs_to_jiffies(DEBOUNCE_TIME));
52 pm_wakeup_event(dev: priv->input->dev.parent, msec: 0);
53 }
54
55 return 0;
56}
57
58static void imx_sc_check_for_events(struct work_struct *work)
59{
60 struct imx_key_drv_data *priv =
61 container_of(work,
62 struct imx_key_drv_data,
63 check_work.work);
64 struct input_dev *input = priv->input;
65 struct imx_sc_msg_key msg;
66 struct imx_sc_rpc_msg *hdr = &msg.hdr;
67 bool state;
68 int error;
69
70 hdr->ver = IMX_SC_RPC_VERSION;
71 hdr->svc = IMX_SC_RPC_SVC_MISC;
72 hdr->func = IMX_SC_MISC_FUNC_GET_BUTTON_STATUS;
73 hdr->size = 1;
74
75 error = imx_scu_call_rpc(ipc: priv->key_ipc_handle, msg: &msg, have_resp: true);
76 if (error) {
77 dev_err(&input->dev, "read imx sc key failed, error %d\n", error);
78 return;
79 }
80
81 /*
82 * The response data from SCU firmware is 4 bytes,
83 * but ONLY the first byte is the key state, other
84 * 3 bytes could be some dirty data, so we should
85 * ONLY take the first byte as key state.
86 */
87 state = (bool)(msg.state & 0xff);
88
89 if (state ^ priv->keystate) {
90 priv->keystate = state;
91 input_event(dev: input, EV_KEY, code: priv->keycode, value: state);
92 input_sync(dev: input);
93 if (!priv->keystate)
94 pm_relax(dev: priv->input->dev.parent);
95 }
96
97 if (state)
98 schedule_delayed_work(dwork: &priv->check_work,
99 delay: msecs_to_jiffies(REPEAT_INTERVAL));
100}
101
102static void imx_sc_key_action(void *data)
103{
104 struct imx_key_drv_data *priv = data;
105
106 imx_scu_irq_group_enable(SC_IRQ_GROUP_WAKE, SC_IRQ_BUTTON, enable: false);
107 imx_scu_irq_unregister_notifier(nb: &priv->key_notifier);
108 cancel_delayed_work_sync(dwork: &priv->check_work);
109}
110
111static int imx_sc_key_probe(struct platform_device *pdev)
112{
113 struct imx_key_drv_data *priv;
114 struct input_dev *input;
115 int error;
116
117 priv = devm_kzalloc(dev: &pdev->dev, size: sizeof(*priv), GFP_KERNEL);
118 if (!priv)
119 return -ENOMEM;
120
121 error = imx_scu_get_handle(ipc: &priv->key_ipc_handle);
122 if (error)
123 return error;
124
125 if (device_property_read_u32(dev: &pdev->dev, propname: "linux,keycodes",
126 val: &priv->keycode)) {
127 dev_err(&pdev->dev, "missing linux,keycodes property\n");
128 return -EINVAL;
129 }
130
131 INIT_DELAYED_WORK(&priv->check_work, imx_sc_check_for_events);
132
133 input = devm_input_allocate_device(&pdev->dev);
134 if (!input) {
135 dev_err(&pdev->dev, "failed to allocate the input device\n");
136 return -ENOMEM;
137 }
138
139 input->name = pdev->name;
140 input->phys = "imx-sc-key/input0";
141 input->id.bustype = BUS_HOST;
142
143 input_set_capability(dev: input, EV_KEY, code: priv->keycode);
144
145 error = input_register_device(input);
146 if (error) {
147 dev_err(&pdev->dev, "failed to register input device\n");
148 return error;
149 }
150
151 priv->input = input;
152 platform_set_drvdata(pdev, data: priv);
153
154 error = imx_scu_irq_group_enable(SC_IRQ_GROUP_WAKE, SC_IRQ_BUTTON,
155 enable: true);
156 if (error) {
157 dev_err(&pdev->dev, "failed to enable scu group irq\n");
158 return error;
159 }
160
161 error = devm_add_action_or_reset(&pdev->dev, imx_sc_key_action, priv);
162 if (error)
163 return error;
164
165 priv->key_notifier.notifier_call = imx_sc_key_notify;
166 error = imx_scu_irq_register_notifier(nb: &priv->key_notifier);
167 if (error)
168 dev_err(&pdev->dev, "failed to register scu notifier\n");
169
170 return error;
171}
172
173static const struct of_device_id imx_sc_key_ids[] = {
174 { .compatible = "fsl,imx-sc-key" },
175 { /* sentinel */ }
176};
177MODULE_DEVICE_TABLE(of, imx_sc_key_ids);
178
179static struct platform_driver imx_sc_key_driver = {
180 .driver = {
181 .name = "imx-sc-key",
182 .of_match_table = imx_sc_key_ids,
183 },
184 .probe = imx_sc_key_probe,
185};
186module_platform_driver(imx_sc_key_driver);
187
188MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
189MODULE_DESCRIPTION("i.MX System Controller Key Driver");
190MODULE_LICENSE("GPL v2");
191

source code of linux/drivers/input/keyboard/imx_sc_key.c