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 bool suspended;
42 struct timer_list check_timer;
43 struct input_dev *input;
44 };
45
bbnsm_pwrkey_check_for_events(struct timer_list * t)46 static void bbnsm_pwrkey_check_for_events(struct timer_list *t)
47 {
48 struct bbnsm_pwrkey *bbnsm = from_timer(bbnsm, t, check_timer);
49 struct input_dev *input = bbnsm->input;
50 u32 state;
51
52 regmap_read(bbnsm->regmap, BBNSM_EVENTS, &state);
53
54 state = state & BBNSM_BTN_PRESSED ? 1 : 0;
55
56 /* only report new event if status changed */
57 if (state ^ bbnsm->keystate) {
58 bbnsm->keystate = state;
59 input_event(input, EV_KEY, bbnsm->keycode, state);
60 input_sync(input);
61 pm_relax(bbnsm->input->dev.parent);
62 }
63
64 /* repeat check if pressed long */
65 if (state)
66 mod_timer(&bbnsm->check_timer,
67 jiffies + msecs_to_jiffies(REPEAT_INTERVAL));
68 }
69
bbnsm_pwrkey_interrupt(int irq,void * dev_id)70 static irqreturn_t bbnsm_pwrkey_interrupt(int irq, void *dev_id)
71 {
72 struct platform_device *pdev = dev_id;
73 struct bbnsm_pwrkey *bbnsm = platform_get_drvdata(pdev);
74 struct input_dev *input = bbnsm->input;
75 u32 event;
76
77 regmap_read(bbnsm->regmap, BBNSM_EVENTS, &event);
78 if (!(event & BBNSM_BTN_OFF))
79 return IRQ_NONE;
80
81 pm_wakeup_event(bbnsm->input->dev.parent, 0);
82
83 /*
84 * Directly report key event after resume to make sure key press
85 * event is never missed.
86 */
87 if (bbnsm->suspended) {
88 bbnsm->keystate = 1;
89 input_event(input, EV_KEY, bbnsm->keycode, 1);
90 input_sync(input);
91 /* Fire at most once per suspend/resume cycle */
92 bbnsm->suspended = false;
93 }
94
95 mod_timer(&bbnsm->check_timer,
96 jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
97
98 /* clear PWR OFF */
99 regmap_write(bbnsm->regmap, BBNSM_EVENTS, BBNSM_BTN_OFF);
100
101 return IRQ_HANDLED;
102 }
103
bbnsm_pwrkey_act(void * pdata)104 static void bbnsm_pwrkey_act(void *pdata)
105 {
106 struct bbnsm_pwrkey *bbnsm = pdata;
107
108 timer_shutdown_sync(&bbnsm->check_timer);
109 }
110
bbnsm_pwrkey_probe(struct platform_device * pdev)111 static int bbnsm_pwrkey_probe(struct platform_device *pdev)
112 {
113 struct bbnsm_pwrkey *bbnsm;
114 struct input_dev *input;
115 struct device_node *np = pdev->dev.of_node;
116 int error;
117
118 bbnsm = devm_kzalloc(&pdev->dev, sizeof(*bbnsm), GFP_KERNEL);
119 if (!bbnsm)
120 return -ENOMEM;
121
122 bbnsm->regmap = syscon_node_to_regmap(np->parent);
123 if (IS_ERR(bbnsm->regmap)) {
124 dev_err(&pdev->dev, "bbnsm pwerkey get regmap failed\n");
125 return PTR_ERR(bbnsm->regmap);
126 }
127
128 if (device_property_read_u32(&pdev->dev, "linux,code",
129 &bbnsm->keycode)) {
130 bbnsm->keycode = KEY_POWER;
131 dev_warn(&pdev->dev, "key code is not specified, using default KEY_POWER\n");
132 }
133
134 bbnsm->irq = platform_get_irq(pdev, 0);
135 if (bbnsm->irq < 0)
136 return -EINVAL;
137
138 /* config the BBNSM power related register */
139 regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, BBNSM_DP_EN, BBNSM_DP_EN);
140
141 /* clear the unexpected interrupt before driver ready */
142 regmap_write_bits(bbnsm->regmap, BBNSM_EVENTS, BBNSM_PWRKEY_EVENTS,
143 BBNSM_PWRKEY_EVENTS);
144
145 timer_setup(&bbnsm->check_timer, bbnsm_pwrkey_check_for_events, 0);
146
147 input = devm_input_allocate_device(&pdev->dev);
148 if (!input) {
149 dev_err(&pdev->dev, "failed to allocate the input device\n");
150 return -ENOMEM;
151 }
152
153 input->name = pdev->name;
154 input->phys = "bbnsm-pwrkey/input0";
155 input->id.bustype = BUS_HOST;
156
157 input_set_capability(input, EV_KEY, bbnsm->keycode);
158
159 /* input customer action to cancel release timer */
160 error = devm_add_action(&pdev->dev, bbnsm_pwrkey_act, bbnsm);
161 if (error) {
162 dev_err(&pdev->dev, "failed to register remove action\n");
163 return error;
164 }
165
166 bbnsm->input = input;
167 platform_set_drvdata(pdev, bbnsm);
168
169 error = devm_request_irq(&pdev->dev, bbnsm->irq, bbnsm_pwrkey_interrupt,
170 IRQF_SHARED, pdev->name, pdev);
171 if (error) {
172 dev_err(&pdev->dev, "interrupt not available.\n");
173 return error;
174 }
175
176 error = input_register_device(input);
177 if (error) {
178 dev_err(&pdev->dev, "failed to register input device\n");
179 return error;
180 }
181
182 device_init_wakeup(&pdev->dev, true);
183 error = dev_pm_set_wake_irq(&pdev->dev, bbnsm->irq);
184 if (error)
185 dev_warn(&pdev->dev, "irq wake enable failed.\n");
186
187 return 0;
188 }
189
bbnsm_pwrkey_suspend(struct device * dev)190 static int __maybe_unused bbnsm_pwrkey_suspend(struct device *dev)
191 {
192 struct platform_device *pdev = to_platform_device(dev);
193 struct bbnsm_pwrkey *bbnsm = platform_get_drvdata(pdev);
194
195 bbnsm->suspended = true;
196
197 return 0;
198 }
199
bbnsm_pwrkey_resume(struct device * dev)200 static int __maybe_unused bbnsm_pwrkey_resume(struct device *dev)
201 {
202 struct platform_device *pdev = to_platform_device(dev);
203 struct bbnsm_pwrkey *bbnsm = platform_get_drvdata(pdev);
204
205 bbnsm->suspended = false;
206
207 return 0;
208 }
209
210 static SIMPLE_DEV_PM_OPS(bbnsm_pwrkey_pm_ops, bbnsm_pwrkey_suspend,
211 bbnsm_pwrkey_resume);
212
213 static const struct of_device_id bbnsm_pwrkey_ids[] = {
214 { .compatible = "nxp,imx93-bbnsm-pwrkey" },
215 { /* sentinel */ }
216 };
217 MODULE_DEVICE_TABLE(of, bbnsm_pwrkey_ids);
218
219 static struct platform_driver bbnsm_pwrkey_driver = {
220 .driver = {
221 .name = "bbnsm_pwrkey",
222 .pm = &bbnsm_pwrkey_pm_ops,
223 .of_match_table = bbnsm_pwrkey_ids,
224 },
225 .probe = bbnsm_pwrkey_probe,
226 };
227 module_platform_driver(bbnsm_pwrkey_driver);
228
229 MODULE_AUTHOR("Jacky Bai <ping.bai@nxp.com>");
230 MODULE_DESCRIPTION("NXP bbnsm power key Driver");
231 MODULE_LICENSE("GPL");
232