max7360-keypad.c

  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
 26struct 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
 36static 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
 84static 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
 99static 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
111static 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
135static 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
178static 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
220static 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
291static 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
297static struct platform_driver max7360_keypad_driver = {
298	.driver = {
299		.name	= "max7360-keypad",
300	},
301	.probe		= max7360_keypad_probe,
302	.remove		= max7360_keypad_remove,
303};
304module_platform_driver(max7360_keypad_driver);
305
306MODULE_DESCRIPTION("MAX7360 Keypad driver");
307MODULE_AUTHOR("Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>");
308MODULE_LICENSE("GPL");