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 */
21enum atc260x_onkey_reset_status {
22	KEY_RESET_HW_DEFAULT,
23	KEY_RESET_DISABLED,
24	KEY_RESET_USER_SEL,
25};
26
27struct 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
40struct 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
48static 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
61static 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
74static 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
101static 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
144static 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
151static 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
173static 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
182static 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
190static 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
294static struct platform_driver atc260x_onkey_driver = {
295	.probe	= atc260x_onkey_probe,
296	.driver	= {
297		.name = "atc260x-onkey",
298	},
299};
300
301module_platform_driver(atc260x_onkey_driver);
302
303MODULE_DESCRIPTION("Onkey driver for ATC260x PMICs");
304MODULE_AUTHOR("Cristian Ciocaltea <cristian.ciocaltea@gmail.com>");
305MODULE_LICENSE("GPL");
306