1// SPDX-License-Identifier: GPL-2.0+
2//
3// Copyright 2022 NXP.
4
5#include <linux/device.h>
6#include <linux/err.h>
7#include <linux/init.h>
8#include <linux/input.h>
9#include <linux/interrupt.h>
10#include <linux/io.h>
11#include <linux/jiffies.h>
12#include <linux/kernel.h>
13#include <linux/mfd/syscon.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/of_address.h>
17#include <linux/platform_device.h>
18#include <linux/pm_wakeirq.h>
19#include <linux/regmap.h>
20
21#define BBNSM_CTRL		0x8
22#define BBNSM_INT_EN		0x10
23#define BBNSM_EVENTS		0x14
24#define BBNSM_PAD_CTRL		0x24
25
26#define BBNSM_BTN_PRESSED	BIT(7)
27#define BBNSM_PWR_ON		BIT(6)
28#define BBNSM_BTN_OFF		BIT(5)
29#define BBNSM_EMG_OFF		BIT(4)
30#define BBNSM_PWRKEY_EVENTS	(BBNSM_PWR_ON | BBNSM_BTN_OFF | BBNSM_EMG_OFF)
31#define BBNSM_DP_EN		BIT(24)
32
33#define DEBOUNCE_TIME		30
34#define REPEAT_INTERVAL		60
35
36struct bbnsm_pwrkey {
37	struct regmap *regmap;
38	int irq;
39	int keycode;
40	int keystate;  /* 1:pressed */
41	struct timer_list check_timer;
42	struct input_dev *input;
43};
44
45static void bbnsm_pwrkey_check_for_events(struct timer_list *t)
46{
47	struct bbnsm_pwrkey *bbnsm = from_timer(bbnsm, t, check_timer);
48	struct input_dev *input = bbnsm->input;
49	u32 state;
50
51	regmap_read(bbnsm->regmap, BBNSM_EVENTS, &state);
52
53	state = state & BBNSM_BTN_PRESSED ? 1 : 0;
54
55	/* only report new event if status changed */
56	if (state ^ bbnsm->keystate) {
57		bbnsm->keystate = state;
58		input_event(input, EV_KEY, bbnsm->keycode, state);
59		input_sync(input);
60		pm_relax(bbnsm->input->dev.parent);
61	}
62
63	/* repeat check if pressed long */
64	if (state)
65		mod_timer(&bbnsm->check_timer,
66			  jiffies + msecs_to_jiffies(REPEAT_INTERVAL));
67}
68
69static irqreturn_t bbnsm_pwrkey_interrupt(int irq, void *dev_id)
70{
71	struct platform_device *pdev = dev_id;
72	struct bbnsm_pwrkey *bbnsm = platform_get_drvdata(pdev);
73	u32 event;
74
75	regmap_read(bbnsm->regmap, BBNSM_EVENTS, &event);
76	if (!(event & BBNSM_BTN_OFF))
77		return IRQ_NONE;
78
79	pm_wakeup_event(bbnsm->input->dev.parent, 0);
80
81	mod_timer(&bbnsm->check_timer,
82		   jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
83
84	/* clear PWR OFF */
85	regmap_write(bbnsm->regmap, BBNSM_EVENTS, BBNSM_BTN_OFF);
86
87	return IRQ_HANDLED;
88}
89
90static void bbnsm_pwrkey_act(void *pdata)
91{
92	struct bbnsm_pwrkey *bbnsm = pdata;
93
94	timer_shutdown_sync(&bbnsm->check_timer);
95}
96
97static int bbnsm_pwrkey_probe(struct platform_device *pdev)
98{
99	struct bbnsm_pwrkey *bbnsm;
100	struct input_dev *input;
101	struct device_node *np = pdev->dev.of_node;
102	int error;
103
104	bbnsm = devm_kzalloc(&pdev->dev, sizeof(*bbnsm), GFP_KERNEL);
105	if (!bbnsm)
106		return -ENOMEM;
107
108	bbnsm->regmap = syscon_node_to_regmap(np->parent);
109	if (IS_ERR(bbnsm->regmap)) {
110		dev_err(&pdev->dev, "bbnsm pwerkey get regmap failed\n");
111		return PTR_ERR(bbnsm->regmap);
112	}
113
114	if (device_property_read_u32(&pdev->dev, "linux,code",
115				     &bbnsm->keycode)) {
116		bbnsm->keycode = KEY_POWER;
117		dev_warn(&pdev->dev, "key code is not specified, using default KEY_POWER\n");
118	}
119
120	bbnsm->irq = platform_get_irq(pdev, 0);
121	if (bbnsm->irq < 0)
122		return -EINVAL;
123
124	/* config the BBNSM power related register */
125	regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, BBNSM_DP_EN, BBNSM_DP_EN);
126
127	/* clear the unexpected interrupt before driver ready */
128	regmap_write_bits(bbnsm->regmap, BBNSM_EVENTS, BBNSM_PWRKEY_EVENTS,
129			  BBNSM_PWRKEY_EVENTS);
130
131	timer_setup(&bbnsm->check_timer, bbnsm_pwrkey_check_for_events, 0);
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 = "bbnsm-pwrkey/input0";
141	input->id.bustype = BUS_HOST;
142
143	input_set_capability(input, EV_KEY, bbnsm->keycode);
144
145	/* input customer action to cancel release timer */
146	error = devm_add_action(&pdev->dev, bbnsm_pwrkey_act, bbnsm);
147	if (error) {
148		dev_err(&pdev->dev, "failed to register remove action\n");
149		return error;
150	}
151
152	bbnsm->input = input;
153	platform_set_drvdata(pdev, bbnsm);
154
155	error = devm_request_irq(&pdev->dev, bbnsm->irq, bbnsm_pwrkey_interrupt,
156				 IRQF_SHARED, pdev->name, pdev);
157	if (error) {
158		dev_err(&pdev->dev, "interrupt not available.\n");
159		return error;
160	}
161
162	error = input_register_device(input);
163	if (error) {
164		dev_err(&pdev->dev, "failed to register input device\n");
165		return error;
166	}
167
168	device_init_wakeup(&pdev->dev, true);
169	error = dev_pm_set_wake_irq(&pdev->dev, bbnsm->irq);
170	if (error)
171		dev_warn(&pdev->dev, "irq wake enable failed.\n");
172
173	return 0;
174}
175
176static const struct of_device_id bbnsm_pwrkey_ids[] = {
177	{ .compatible = "nxp,imx93-bbnsm-pwrkey" },
178	{ /* sentinel */ }
179};
180MODULE_DEVICE_TABLE(of, bbnsm_pwrkey_ids);
181
182static struct platform_driver bbnsm_pwrkey_driver = {
183	.driver = {
184		.name = "bbnsm_pwrkey",
185		.of_match_table = bbnsm_pwrkey_ids,
186	},
187	.probe = bbnsm_pwrkey_probe,
188};
189module_platform_driver(bbnsm_pwrkey_driver);
190
191MODULE_AUTHOR("Jacky Bai <ping.bai@nxp.com>");
192MODULE_DESCRIPTION("NXP bbnsm power key Driver");
193MODULE_LICENSE("GPL");
194