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(&priv->check_work,
 51				      msecs_to_jiffies(DEBOUNCE_TIME));
 52		pm_wakeup_event(priv->input->dev.parent, 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(priv->key_ipc_handle, &msg, 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(input, EV_KEY, priv->keycode, state);
 92		input_sync(input);
 93		if (!priv->keystate)
 94			pm_relax(priv->input->dev.parent);
 95	}
 96
 97	if (state)
 98		schedule_delayed_work(&priv->check_work,
 99				      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, false);
107	imx_scu_irq_unregister_notifier(&priv->key_notifier);
108	cancel_delayed_work_sync(&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(&pdev->dev, sizeof(*priv), GFP_KERNEL);
118	if (!priv)
119		return -ENOMEM;
120
121	error = imx_scu_get_handle(&priv->key_ipc_handle);
122	if (error)
123		return error;
124
125	if (device_property_read_u32(&pdev->dev, "linux,keycodes",
126				     &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(input, EV_KEY, 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, priv);
153
154	error = imx_scu_irq_group_enable(SC_IRQ_GROUP_WAKE, SC_IRQ_BUTTON,
155					 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(&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");