1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Onkey driver for Actions Semi ATC260x PMICs.
4  *
5  * Copyright (c) 2020 Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
6  */
7 
8 #include <linux/bitfield.h>
9 #include <linux/input.h>
10 #include <linux/interrupt.h>
11 #include <linux/mfd/atc260x/core.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/platform_device.h>
15 #include <linux/regmap.h>
16 
17 /* <2s for short press, >2s for long press */
18 #define KEY_PRESS_TIME_SEC	2
19 
20 /* Driver internals */
21 enum atc260x_onkey_reset_status {
22 	KEY_RESET_HW_DEFAULT,
23 	KEY_RESET_DISABLED,
24 	KEY_RESET_USER_SEL,
25 };
26 
27 struct atc260x_onkey_params {
28 	u32 reg_int_ctl;
29 	u32 kdwn_state_bm;
30 	u32 long_int_pnd_bm;
31 	u32 short_int_pnd_bm;
32 	u32 kdwn_int_pnd_bm;
33 	u32 press_int_en_bm;
34 	u32 kdwn_int_en_bm;
35 	u32 press_time_bm;
36 	u32 reset_en_bm;
37 	u32 reset_time_bm;
38 };
39 
40 struct atc260x_onkey {
41 	struct atc260x *atc260x;
42 	const struct atc260x_onkey_params *params;
43 	struct input_dev *input_dev;
44 	struct delayed_work work;
45 	int irq;
46 };
47 
48 static const struct atc260x_onkey_params atc2603c_onkey_params = {
49 	.reg_int_ctl		= ATC2603C_PMU_SYS_CTL2,
50 	.long_int_pnd_bm	= ATC2603C_PMU_SYS_CTL2_ONOFF_LONG_PRESS,
51 	.short_int_pnd_bm	= ATC2603C_PMU_SYS_CTL2_ONOFF_SHORT_PRESS,
52 	.kdwn_int_pnd_bm	= ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_PD,
53 	.press_int_en_bm	= ATC2603C_PMU_SYS_CTL2_ONOFF_INT_EN,
54 	.kdwn_int_en_bm		= ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_INT_EN,
55 	.kdwn_state_bm		= ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS,
56 	.press_time_bm		= ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_TIME,
57 	.reset_en_bm		= ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_RESET_EN,
58 	.reset_time_bm		= ATC2603C_PMU_SYS_CTL2_ONOFF_RESET_TIME_SEL,
59 };
60 
61 static const struct atc260x_onkey_params atc2609a_onkey_params = {
62 	.reg_int_ctl		= ATC2609A_PMU_SYS_CTL2,
63 	.long_int_pnd_bm	= ATC2609A_PMU_SYS_CTL2_ONOFF_LONG_PRESS,
64 	.short_int_pnd_bm	= ATC2609A_PMU_SYS_CTL2_ONOFF_SHORT_PRESS,
65 	.kdwn_int_pnd_bm	= ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS_PD,
66 	.press_int_en_bm	= ATC2609A_PMU_SYS_CTL2_ONOFF_LSP_INT_EN,
67 	.kdwn_int_en_bm		= ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS_INT_EN,
68 	.kdwn_state_bm		= ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS,
69 	.press_time_bm		= ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS_TIME,
70 	.reset_en_bm		= ATC2609A_PMU_SYS_CTL2_ONOFF_RESET_EN,
71 	.reset_time_bm		= ATC2609A_PMU_SYS_CTL2_ONOFF_RESET_TIME_SEL,
72 };
73 
74 static int atc2603x_onkey_hw_init(struct atc260x_onkey *onkey,
75 				  enum atc260x_onkey_reset_status reset_status,
76 				  u32 reset_time, u32 press_time)
77 {
78 	u32 reg_bm, reg_val;
79 
80 	reg_bm = onkey->params->long_int_pnd_bm |
81 		 onkey->params->short_int_pnd_bm |
82 		 onkey->params->kdwn_int_pnd_bm |
83 		 onkey->params->press_int_en_bm |
84 		 onkey->params->kdwn_int_en_bm;
85 
86 	reg_val = reg_bm | press_time;
87 	reg_bm |= onkey->params->press_time_bm;
88 
89 	if (reset_status == KEY_RESET_DISABLED) {
90 		reg_bm |= onkey->params->reset_en_bm;
91 	} else if (reset_status == KEY_RESET_USER_SEL) {
92 		reg_bm |= onkey->params->reset_en_bm |
93 			  onkey->params->reset_time_bm;
94 		reg_val |= onkey->params->reset_en_bm | reset_time;
95 	}
96 
97 	return regmap_update_bits(onkey->atc260x->regmap,
98 				  onkey->params->reg_int_ctl, reg_bm, reg_val);
99 }
100 
101 static void atc260x_onkey_query(struct atc260x_onkey *onkey)
102 {
103 	u32 reg_bits;
104 	int ret, key_down;
105 
106 	ret = regmap_read(onkey->atc260x->regmap,
107 			  onkey->params->reg_int_ctl, &key_down);
108 	if (ret) {
109 		key_down = 1;
110 		dev_err(onkey->atc260x->dev,
111 			"Failed to read onkey status: %d\n", ret);
112 	} else {
113 		key_down &= onkey->params->kdwn_state_bm;
114 	}
115 
116 	/*
117 	 * The hardware generates interrupt only when the onkey pin is
118 	 * asserted. Hence, the deassertion of the pin is simulated through
119 	 * work queue.
120 	 */
121 	if (key_down) {
122 		schedule_delayed_work(&onkey->work, msecs_to_jiffies(200));
123 		return;
124 	}
125 
126 	/*
127 	 * The key-down status bit is cleared when the On/Off button
128 	 * is released.
129 	 */
130 	input_report_key(onkey->input_dev, KEY_POWER, 0);
131 	input_sync(onkey->input_dev);
132 
133 	reg_bits = onkey->params->long_int_pnd_bm |
134 		   onkey->params->short_int_pnd_bm |
135 		   onkey->params->kdwn_int_pnd_bm |
136 		   onkey->params->press_int_en_bm |
137 		   onkey->params->kdwn_int_en_bm;
138 
139 	/* Clear key press pending events and enable key press interrupts. */
140 	regmap_update_bits(onkey->atc260x->regmap, onkey->params->reg_int_ctl,
141 			   reg_bits, reg_bits);
142 }
143 
144 static void atc260x_onkey_work(struct work_struct *work)
145 {
146 	struct atc260x_onkey *onkey = container_of(work, struct atc260x_onkey,
147 						   work.work);
148 	atc260x_onkey_query(onkey);
149 }
150 
151 static irqreturn_t atc260x_onkey_irq(int irq, void *data)
152 {
153 	struct atc260x_onkey *onkey = data;
154 	int ret;
155 
156 	/* Disable key press interrupts. */
157 	ret = regmap_update_bits(onkey->atc260x->regmap,
158 				 onkey->params->reg_int_ctl,
159 				 onkey->params->press_int_en_bm |
160 				 onkey->params->kdwn_int_en_bm, 0);
161 	if (ret)
162 		dev_err(onkey->atc260x->dev,
163 			"Failed to disable interrupts: %d\n", ret);
164 
165 	input_report_key(onkey->input_dev, KEY_POWER, 1);
166 	input_sync(onkey->input_dev);
167 
168 	atc260x_onkey_query(onkey);
169 
170 	return IRQ_HANDLED;
171 }
172 
173 static int atc260x_onkey_open(struct input_dev *dev)
174 {
175 	struct atc260x_onkey *onkey = input_get_drvdata(dev);
176 
177 	enable_irq(onkey->irq);
178 
179 	return 0;
180 }
181 
182 static void atc260x_onkey_close(struct input_dev *dev)
183 {
184 	struct atc260x_onkey *onkey = input_get_drvdata(dev);
185 
186 	disable_irq(onkey->irq);
187 	cancel_delayed_work_sync(&onkey->work);
188 }
189 
190 static int atc260x_onkey_probe(struct platform_device *pdev)
191 {
192 	struct atc260x *atc260x = dev_get_drvdata(pdev->dev.parent);
193 	struct atc260x_onkey *onkey;
194 	struct input_dev *input_dev;
195 	enum atc260x_onkey_reset_status reset_status;
196 	u32 press_time = KEY_PRESS_TIME_SEC, reset_time = 0;
197 	int val, error;
198 
199 	onkey = devm_kzalloc(&pdev->dev, sizeof(*onkey), GFP_KERNEL);
200 	if (!onkey)
201 		return -ENOMEM;
202 
203 	error = device_property_read_u32(pdev->dev.parent,
204 					 "reset-time-sec", &val);
205 	if (error) {
206 		reset_status = KEY_RESET_HW_DEFAULT;
207 	} else if (val) {
208 		if (val < 6 || val > 12) {
209 			dev_err(&pdev->dev, "reset-time-sec out of range\n");
210 			return -EINVAL;
211 		}
212 
213 		reset_status = KEY_RESET_USER_SEL;
214 		reset_time = (val - 6) / 2;
215 	} else {
216 		reset_status = KEY_RESET_DISABLED;
217 		dev_dbg(&pdev->dev, "Disabled reset on long-press\n");
218 	}
219 
220 	switch (atc260x->ic_type) {
221 	case ATC2603C:
222 		onkey->params = &atc2603c_onkey_params;
223 		press_time = FIELD_PREP(ATC2603C_PMU_SYS_CTL2_ONOFF_PRESS_TIME,
224 					press_time);
225 		reset_time = FIELD_PREP(ATC2603C_PMU_SYS_CTL2_ONOFF_RESET_TIME_SEL,
226 					reset_time);
227 		break;
228 	case ATC2609A:
229 		onkey->params = &atc2609a_onkey_params;
230 		press_time = FIELD_PREP(ATC2609A_PMU_SYS_CTL2_ONOFF_PRESS_TIME,
231 					press_time);
232 		reset_time = FIELD_PREP(ATC2609A_PMU_SYS_CTL2_ONOFF_RESET_TIME_SEL,
233 					reset_time);
234 		break;
235 	default:
236 		dev_err(&pdev->dev,
237 			"OnKey not supported for ATC260x PMIC type: %u\n",
238 			atc260x->ic_type);
239 		return -EINVAL;
240 	}
241 
242 	input_dev = devm_input_allocate_device(&pdev->dev);
243 	if (!input_dev) {
244 		dev_err(&pdev->dev, "Failed to allocate input device\n");
245 		return -ENOMEM;
246 	}
247 
248 	onkey->input_dev = input_dev;
249 	onkey->atc260x = atc260x;
250 
251 	input_dev->name = "atc260x-onkey";
252 	input_dev->phys = "atc260x-onkey/input0";
253 	input_dev->open = atc260x_onkey_open;
254 	input_dev->close = atc260x_onkey_close;
255 
256 	input_set_capability(input_dev, EV_KEY, KEY_POWER);
257 	input_set_drvdata(input_dev, onkey);
258 
259 	INIT_DELAYED_WORK(&onkey->work, atc260x_onkey_work);
260 
261 	onkey->irq = platform_get_irq(pdev, 0);
262 	if (onkey->irq < 0)
263 		return onkey->irq;
264 
265 	error = devm_request_threaded_irq(&pdev->dev, onkey->irq, NULL,
266 					  atc260x_onkey_irq, IRQF_ONESHOT,
267 					  dev_name(&pdev->dev), onkey);
268 	if (error) {
269 		dev_err(&pdev->dev,
270 			"Failed to register IRQ %d: %d\n", onkey->irq, error);
271 		return error;
272 	}
273 
274 	/* Keep IRQ disabled until atc260x_onkey_open() is called. */
275 	disable_irq(onkey->irq);
276 
277 	error = input_register_device(input_dev);
278 	if (error) {
279 		dev_err(&pdev->dev,
280 			"Failed to register input device: %d\n", error);
281 		return error;
282 	}
283 
284 	error = atc2603x_onkey_hw_init(onkey, reset_status,
285 				       reset_time, press_time);
286 	if (error)
287 		return error;
288 
289 	device_init_wakeup(&pdev->dev, true);
290 
291 	return 0;
292 }
293 
294 static struct platform_driver atc260x_onkey_driver = {
295 	.probe	= atc260x_onkey_probe,
296 	.driver	= {
297 		.name = "atc260x-onkey",
298 	},
299 };
300 
301 module_platform_driver(atc260x_onkey_driver);
302 
303 MODULE_DESCRIPTION("Onkey driver for ATC260x PMICs");
304 MODULE_AUTHOR("Cristian Ciocaltea <cristian.ciocaltea@gmail.com>");
305 MODULE_LICENSE("GPL");
306