xref: /linux/drivers/input/keyboard/max7360-keypad.c (revision 55a42f78ffd386e01a5404419f8c5ded7db70a21)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2025 Bootlin
4  *
5  * Author: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
6  */
7 
8 #include <linux/bitfield.h>
9 #include <linux/bitops.h>
10 #include <linux/dev_printk.h>
11 #include <linux/device/devres.h>
12 #include <linux/err.h>
13 #include <linux/init.h>
14 #include <linux/input.h>
15 #include <linux/input/matrix_keypad.h>
16 #include <linux/interrupt.h>
17 #include <linux/mfd/max7360.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/minmax.h>
20 #include <linux/module.h>
21 #include <linux/property.h>
22 #include <linux/platform_device.h>
23 #include <linux/pm_wakeirq.h>
24 #include <linux/regmap.h>
25 
26 struct max7360_keypad {
27 	struct input_dev *input;
28 	unsigned int rows;
29 	unsigned int cols;
30 	unsigned int debounce_ms;
31 	int irq;
32 	struct regmap *regmap;
33 	unsigned short keycodes[MAX7360_MAX_KEY_ROWS * MAX7360_MAX_KEY_COLS];
34 };
35 
36 static irqreturn_t max7360_keypad_irq(int irq, void *data)
37 {
38 	struct max7360_keypad *max7360_keypad = data;
39 	struct device *dev = max7360_keypad->input->dev.parent;
40 	unsigned int val;
41 	unsigned int row, col;
42 	unsigned int release;
43 	unsigned int code;
44 	int error;
45 
46 	error = regmap_read(max7360_keypad->regmap, MAX7360_REG_KEYFIFO, &val);
47 	if (error) {
48 		dev_err(dev, "Failed to read MAX7360 FIFO");
49 		return IRQ_NONE;
50 	}
51 
52 	/* FIFO overflow: ignore it and get next event. */
53 	if (val == MAX7360_FIFO_OVERFLOW) {
54 		dev_warn(dev, "max7360 FIFO overflow");
55 		error = regmap_read_poll_timeout(max7360_keypad->regmap, MAX7360_REG_KEYFIFO,
56 						 val, val != MAX7360_FIFO_OVERFLOW, 0, 1000);
57 		if (error) {
58 			dev_err(dev, "Failed to empty MAX7360 FIFO");
59 			return IRQ_NONE;
60 		}
61 	}
62 
63 	if (val == MAX7360_FIFO_EMPTY) {
64 		dev_dbg(dev, "Got a spurious interrupt");
65 
66 		return IRQ_NONE;
67 	}
68 
69 	row = FIELD_GET(MAX7360_FIFO_ROW, val);
70 	col = FIELD_GET(MAX7360_FIFO_COL, val);
71 	release = val & MAX7360_FIFO_RELEASE;
72 
73 	code = MATRIX_SCAN_CODE(row, col, get_count_order(max7360_keypad->cols));
74 
75 	dev_dbg(dev, "key[%d:%d] %s\n", row, col, release ? "release" : "press");
76 
77 	input_event(max7360_keypad->input, EV_MSC, MSC_SCAN, code);
78 	input_report_key(max7360_keypad->input, max7360_keypad->keycodes[code], !release);
79 	input_sync(max7360_keypad->input);
80 
81 	return IRQ_HANDLED;
82 }
83 
84 static int max7360_keypad_open(struct input_dev *pdev)
85 {
86 	struct max7360_keypad *max7360_keypad = input_get_drvdata(pdev);
87 	struct device *dev = max7360_keypad->input->dev.parent;
88 	int error;
89 
90 	/* Somebody is using the device: get out of sleep. */
91 	error = regmap_write_bits(max7360_keypad->regmap, MAX7360_REG_CONFIG,
92 				  MAX7360_CFG_SLEEP, MAX7360_CFG_SLEEP);
93 	if (error)
94 		dev_err(dev, "Failed to write max7360 configuration: %d\n", error);
95 
96 	return error;
97 }
98 
99 static void max7360_keypad_close(struct input_dev *pdev)
100 {
101 	struct max7360_keypad *max7360_keypad = input_get_drvdata(pdev);
102 	struct device *dev = max7360_keypad->input->dev.parent;
103 	int error;
104 
105 	/* Nobody is using the device anymore: go to sleep. */
106 	error = regmap_write_bits(max7360_keypad->regmap, MAX7360_REG_CONFIG, MAX7360_CFG_SLEEP, 0);
107 	if (error)
108 		dev_err(dev, "Failed to write max7360 configuration: %d\n", error);
109 }
110 
111 static int max7360_keypad_hw_init(struct max7360_keypad *max7360_keypad)
112 {
113 	struct device *dev = max7360_keypad->input->dev.parent;
114 	unsigned int val;
115 	int error;
116 
117 	val = max7360_keypad->debounce_ms - MAX7360_DEBOUNCE_MIN;
118 	error = regmap_write_bits(max7360_keypad->regmap, MAX7360_REG_DEBOUNCE,
119 				  MAX7360_DEBOUNCE,
120 				  FIELD_PREP(MAX7360_DEBOUNCE, val));
121 	if (error)
122 		return dev_err_probe(dev, error,
123 				     "Failed to write max7360 debounce configuration\n");
124 
125 	error = regmap_write_bits(max7360_keypad->regmap, MAX7360_REG_INTERRUPT,
126 				  MAX7360_INTERRUPT_TIME_MASK,
127 				  FIELD_PREP(MAX7360_INTERRUPT_TIME_MASK, 1));
128 	if (error)
129 		return dev_err_probe(dev, error,
130 				     "Failed to write max7360 keypad interrupt configuration\n");
131 
132 	return 0;
133 }
134 
135 static int max7360_keypad_build_keymap(struct max7360_keypad *max7360_keypad)
136 {
137 	struct input_dev *input_dev = max7360_keypad->input;
138 	struct device *dev = input_dev->dev.parent->parent;
139 	struct matrix_keymap_data keymap_data;
140 	const char *propname = "linux,keymap";
141 	unsigned int max_keys;
142 	int error;
143 	int size;
144 
145 	size = device_property_count_u32(dev, propname);
146 	if (size <= 0) {
147 		dev_err(dev, "missing or malformed property %s: %d\n", propname, size);
148 		return size < 0 ? size : -EINVAL;
149 	}
150 
151 	max_keys = max7360_keypad->cols * max7360_keypad->rows;
152 	if (size > max_keys) {
153 		dev_err(dev, "%s size overflow (%d vs max %u)\n", propname, size, max_keys);
154 		return -EINVAL;
155 	}
156 
157 	u32 *keys __free(kfree) = kmalloc_array(size, sizeof(*keys), GFP_KERNEL);
158 	if (!keys)
159 		return -ENOMEM;
160 
161 	error = device_property_read_u32_array(dev, propname, keys, size);
162 	if (error) {
163 		dev_err(dev, "failed to read %s property: %d\n", propname, error);
164 		return error;
165 	}
166 
167 	keymap_data.keymap = keys;
168 	keymap_data.keymap_size = size;
169 	error = matrix_keypad_build_keymap(&keymap_data, NULL,
170 					   max7360_keypad->rows, max7360_keypad->cols,
171 					   max7360_keypad->keycodes, max7360_keypad->input);
172 	if (error)
173 		return error;
174 
175 	return 0;
176 }
177 
178 static int max7360_keypad_parse_fw(struct device *dev,
179 				   struct max7360_keypad *max7360_keypad,
180 				   bool *autorepeat)
181 {
182 	int error;
183 
184 	error = matrix_keypad_parse_properties(dev->parent, &max7360_keypad->rows,
185 					       &max7360_keypad->cols);
186 	if (error)
187 		return error;
188 
189 	if (!max7360_keypad->rows || !max7360_keypad->cols ||
190 	    max7360_keypad->rows > MAX7360_MAX_KEY_ROWS ||
191 	    max7360_keypad->cols > MAX7360_MAX_KEY_COLS) {
192 		dev_err(dev, "Invalid number of columns or rows (%ux%u)\n",
193 			max7360_keypad->cols, max7360_keypad->rows);
194 		return -EINVAL;
195 	}
196 
197 	*autorepeat = device_property_read_bool(dev->parent, "autorepeat");
198 
199 	max7360_keypad->debounce_ms = MAX7360_DEBOUNCE_MIN;
200 	error = device_property_read_u32(dev->parent, "keypad-debounce-delay-ms",
201 					 &max7360_keypad->debounce_ms);
202 	if (error == -EINVAL) {
203 		dev_info(dev, "Using default keypad-debounce-delay-ms: %u\n",
204 			 max7360_keypad->debounce_ms);
205 	} else if (error < 0) {
206 		dev_err(dev, "Failed to read keypad-debounce-delay-ms property\n");
207 		return error;
208 	}
209 
210 	if (!in_range(max7360_keypad->debounce_ms, MAX7360_DEBOUNCE_MIN,
211 		      MAX7360_DEBOUNCE_MAX - MAX7360_DEBOUNCE_MIN + 1)) {
212 		dev_err(dev, "Invalid keypad-debounce-delay-ms: %u, should be between %u and %u.\n",
213 			max7360_keypad->debounce_ms, MAX7360_DEBOUNCE_MIN, MAX7360_DEBOUNCE_MAX);
214 		return -EINVAL;
215 	}
216 
217 	return 0;
218 }
219 
220 static int max7360_keypad_probe(struct platform_device *pdev)
221 {
222 	struct max7360_keypad *max7360_keypad;
223 	struct device *dev = &pdev->dev;
224 	struct input_dev *input;
225 	struct regmap *regmap;
226 	bool autorepeat;
227 	int error;
228 	int irq;
229 
230 	regmap = dev_get_regmap(dev->parent, NULL);
231 	if (!regmap)
232 		return dev_err_probe(dev, -ENODEV, "Could not get parent regmap\n");
233 
234 	irq = fwnode_irq_get_byname(dev_fwnode(dev->parent), "intk");
235 	if (irq < 0)
236 		return dev_err_probe(dev, irq, "Failed to get IRQ\n");
237 
238 	max7360_keypad = devm_kzalloc(dev, sizeof(*max7360_keypad), GFP_KERNEL);
239 	if (!max7360_keypad)
240 		return -ENOMEM;
241 
242 	max7360_keypad->regmap = regmap;
243 
244 	error = max7360_keypad_parse_fw(dev, max7360_keypad, &autorepeat);
245 	if (error)
246 		return error;
247 
248 	input = devm_input_allocate_device(dev);
249 	if (!input)
250 		return -ENOMEM;
251 
252 	max7360_keypad->input = input;
253 
254 	input->id.bustype = BUS_I2C;
255 	input->name = pdev->name;
256 	input->open = max7360_keypad_open;
257 	input->close = max7360_keypad_close;
258 
259 	error = max7360_keypad_build_keymap(max7360_keypad);
260 	if (error)
261 		return dev_err_probe(dev, error, "Failed to build keymap\n");
262 
263 	input_set_capability(input, EV_MSC, MSC_SCAN);
264 	if (autorepeat)
265 		__set_bit(EV_REP, input->evbit);
266 
267 	input_set_drvdata(input, max7360_keypad);
268 
269 	error = devm_request_threaded_irq(dev, irq, NULL, max7360_keypad_irq,
270 					  IRQF_ONESHOT,
271 					  "max7360-keypad", max7360_keypad);
272 	if (error)
273 		return dev_err_probe(dev, error, "Failed to register interrupt\n");
274 
275 	error = input_register_device(input);
276 	if (error)
277 		return dev_err_probe(dev, error, "Could not register input device\n");
278 
279 	error = max7360_keypad_hw_init(max7360_keypad);
280 	if (error)
281 		return dev_err_probe(dev, error, "Failed to initialize max7360 keypad\n");
282 
283 	device_init_wakeup(dev, true);
284 	error = dev_pm_set_wake_irq(dev, irq);
285 	if (error)
286 		dev_warn(dev, "Failed to set up wakeup irq: %d\n", error);
287 
288 	return 0;
289 }
290 
291 static void max7360_keypad_remove(struct platform_device *pdev)
292 {
293 	dev_pm_clear_wake_irq(&pdev->dev);
294 	device_init_wakeup(&pdev->dev, false);
295 }
296 
297 static struct platform_driver max7360_keypad_driver = {
298 	.driver = {
299 		.name	= "max7360-keypad",
300 	},
301 	.probe		= max7360_keypad_probe,
302 	.remove		= max7360_keypad_remove,
303 };
304 module_platform_driver(max7360_keypad_driver);
305 
306 MODULE_DESCRIPTION("MAX7360 Keypad driver");
307 MODULE_AUTHOR("Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>");
308 MODULE_LICENSE("GPL");
309