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 
36 struct 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 
bbnsm_pwrkey_check_for_events(struct timer_list * t)45 static 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 
bbnsm_pwrkey_interrupt(int irq,void * dev_id)69 static 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 
bbnsm_pwrkey_act(void * pdata)90 static void bbnsm_pwrkey_act(void *pdata)
91 {
92 	struct bbnsm_pwrkey *bbnsm = pdata;
93 
94 	timer_shutdown_sync(&bbnsm->check_timer);
95 }
96 
bbnsm_pwrkey_probe(struct platform_device * pdev)97 static 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 
176 static const struct of_device_id bbnsm_pwrkey_ids[] = {
177 	{ .compatible = "nxp,imx93-bbnsm-pwrkey" },
178 	{ /* sentinel */ }
179 };
180 MODULE_DEVICE_TABLE(of, bbnsm_pwrkey_ids);
181 
182 static 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 };
189 module_platform_driver(bbnsm_pwrkey_driver);
190 
191 MODULE_AUTHOR("Jacky Bai <ping.bai@nxp.com>");
192 MODULE_DESCRIPTION("NXP bbnsm power key Driver");
193 MODULE_LICENSE("GPL");
194