xref: /linux/drivers/input/keyboard/stmpe-keypad.c (revision e7d759f31ca295d589f7420719c311870bb3166f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) ST-Ericsson SA 2010
4  *
5  * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
6  */
7 
8 #include <linux/module.h>
9 #include <linux/slab.h>
10 #include <linux/input.h>
11 #include <linux/interrupt.h>
12 #include <linux/of.h>
13 #include <linux/platform_device.h>
14 #include <linux/input/matrix_keypad.h>
15 #include <linux/mfd/stmpe.h>
16 
17 /* These are at the same addresses in all STMPE variants */
18 #define STMPE_KPC_COL			0x60
19 #define STMPE_KPC_ROW_MSB		0x61
20 #define STMPE_KPC_ROW_LSB		0x62
21 #define STMPE_KPC_CTRL_MSB		0x63
22 #define STMPE_KPC_CTRL_LSB		0x64
23 #define STMPE_KPC_COMBI_KEY_0		0x65
24 #define STMPE_KPC_COMBI_KEY_1		0x66
25 #define STMPE_KPC_COMBI_KEY_2		0x67
26 #define STMPE_KPC_DATA_BYTE0		0x68
27 #define STMPE_KPC_DATA_BYTE1		0x69
28 #define STMPE_KPC_DATA_BYTE2		0x6a
29 #define STMPE_KPC_DATA_BYTE3		0x6b
30 #define STMPE_KPC_DATA_BYTE4		0x6c
31 
32 #define STMPE_KPC_CTRL_LSB_SCAN		(0x1 << 0)
33 #define STMPE_KPC_CTRL_LSB_DEBOUNCE	(0x7f << 1)
34 #define STMPE_KPC_CTRL_MSB_SCAN_COUNT	(0xf << 4)
35 
36 #define STMPE_KPC_ROW_MSB_ROWS		0xff
37 
38 #define STMPE_KPC_DATA_UP		(0x1 << 7)
39 #define STMPE_KPC_DATA_ROW		(0xf << 3)
40 #define STMPE_KPC_DATA_COL		(0x7 << 0)
41 #define STMPE_KPC_DATA_NOKEY_MASK	0x78
42 
43 #define STMPE_KEYPAD_MAX_DEBOUNCE	127
44 #define STMPE_KEYPAD_MAX_SCAN_COUNT	15
45 
46 #define STMPE_KEYPAD_MAX_ROWS		8
47 #define STMPE_KEYPAD_MAX_COLS		8
48 #define STMPE_KEYPAD_ROW_SHIFT		3
49 #define STMPE_KEYPAD_KEYMAP_MAX_SIZE \
50 	(STMPE_KEYPAD_MAX_ROWS * STMPE_KEYPAD_MAX_COLS)
51 
52 
53 #define STMPE1601_NUM_DATA	5
54 #define STMPE2401_NUM_DATA	3
55 #define STMPE2403_NUM_DATA	5
56 
57 /* Make sure it covers all cases above */
58 #define MAX_NUM_DATA		5
59 
60 /**
61  * struct stmpe_keypad_variant - model-specific attributes
62  * @auto_increment: whether the KPC_DATA_BYTE register address
63  *		    auto-increments on multiple read
64  * @set_pullup: whether the pins need to have their pull-ups set
65  * @num_data: number of data bytes
66  * @num_normal_data: number of normal keys' data bytes
67  * @max_cols: maximum number of columns supported
68  * @max_rows: maximum number of rows supported
69  * @col_gpios: bitmask of gpios which can be used for columns
70  * @row_gpios: bitmask of gpios which can be used for rows
71  */
72 struct stmpe_keypad_variant {
73 	bool		auto_increment;
74 	bool		set_pullup;
75 	int		num_data;
76 	int		num_normal_data;
77 	int		max_cols;
78 	int		max_rows;
79 	unsigned int	col_gpios;
80 	unsigned int	row_gpios;
81 };
82 
83 static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
84 	[STMPE1601] = {
85 		.auto_increment		= true,
86 		.num_data		= STMPE1601_NUM_DATA,
87 		.num_normal_data	= 3,
88 		.max_cols		= 8,
89 		.max_rows		= 8,
90 		.col_gpios		= 0x000ff,	/* GPIO 0 - 7 */
91 		.row_gpios		= 0x0ff00,	/* GPIO 8 - 15 */
92 	},
93 	[STMPE2401] = {
94 		.auto_increment		= false,
95 		.set_pullup		= true,
96 		.num_data		= STMPE2401_NUM_DATA,
97 		.num_normal_data	= 2,
98 		.max_cols		= 8,
99 		.max_rows		= 12,
100 		.col_gpios		= 0x0000ff,	/* GPIO 0 - 7*/
101 		.row_gpios		= 0x1f7f00,	/* GPIO 8-14, 16-20 */
102 	},
103 	[STMPE2403] = {
104 		.auto_increment		= true,
105 		.set_pullup		= true,
106 		.num_data		= STMPE2403_NUM_DATA,
107 		.num_normal_data	= 3,
108 		.max_cols		= 8,
109 		.max_rows		= 12,
110 		.col_gpios		= 0x0000ff,	/* GPIO 0 - 7*/
111 		.row_gpios		= 0x1fef00,	/* GPIO 8-14, 16-20 */
112 	},
113 };
114 
115 /**
116  * struct stmpe_keypad - STMPE keypad state container
117  * @stmpe: pointer to parent STMPE device
118  * @input: spawned input device
119  * @variant: STMPE variant
120  * @debounce_ms: debounce interval, in ms.  Maximum is
121  *		 %STMPE_KEYPAD_MAX_DEBOUNCE.
122  * @scan_count: number of key scanning cycles to confirm key data.
123  *		Maximum is %STMPE_KEYPAD_MAX_SCAN_COUNT.
124  * @no_autorepeat: disable key autorepeat
125  * @rows: bitmask for the rows
126  * @cols: bitmask for the columns
127  * @keymap: the keymap
128  */
129 struct stmpe_keypad {
130 	struct stmpe *stmpe;
131 	struct input_dev *input;
132 	const struct stmpe_keypad_variant *variant;
133 	unsigned int debounce_ms;
134 	unsigned int scan_count;
135 	bool no_autorepeat;
136 	unsigned int rows;
137 	unsigned int cols;
138 	unsigned short keymap[STMPE_KEYPAD_KEYMAP_MAX_SIZE];
139 };
140 
141 static int stmpe_keypad_read_data(struct stmpe_keypad *keypad, u8 *data)
142 {
143 	const struct stmpe_keypad_variant *variant = keypad->variant;
144 	struct stmpe *stmpe = keypad->stmpe;
145 	int ret;
146 	int i;
147 
148 	if (variant->auto_increment)
149 		return stmpe_block_read(stmpe, STMPE_KPC_DATA_BYTE0,
150 					variant->num_data, data);
151 
152 	for (i = 0; i < variant->num_data; i++) {
153 		ret = stmpe_reg_read(stmpe, STMPE_KPC_DATA_BYTE0 + i);
154 		if (ret < 0)
155 			return ret;
156 
157 		data[i] = ret;
158 	}
159 
160 	return 0;
161 }
162 
163 static irqreturn_t stmpe_keypad_irq(int irq, void *dev)
164 {
165 	struct stmpe_keypad *keypad = dev;
166 	struct input_dev *input = keypad->input;
167 	const struct stmpe_keypad_variant *variant = keypad->variant;
168 	u8 fifo[MAX_NUM_DATA];
169 	int ret;
170 	int i;
171 
172 	ret = stmpe_keypad_read_data(keypad, fifo);
173 	if (ret < 0)
174 		return IRQ_NONE;
175 
176 	for (i = 0; i < variant->num_normal_data; i++) {
177 		u8 data = fifo[i];
178 		int row = (data & STMPE_KPC_DATA_ROW) >> 3;
179 		int col = data & STMPE_KPC_DATA_COL;
180 		int code = MATRIX_SCAN_CODE(row, col, STMPE_KEYPAD_ROW_SHIFT);
181 		bool up = data & STMPE_KPC_DATA_UP;
182 
183 		if ((data & STMPE_KPC_DATA_NOKEY_MASK)
184 			== STMPE_KPC_DATA_NOKEY_MASK)
185 			continue;
186 
187 		input_event(input, EV_MSC, MSC_SCAN, code);
188 		input_report_key(input, keypad->keymap[code], !up);
189 		input_sync(input);
190 	}
191 
192 	return IRQ_HANDLED;
193 }
194 
195 static int stmpe_keypad_altfunc_init(struct stmpe_keypad *keypad)
196 {
197 	const struct stmpe_keypad_variant *variant = keypad->variant;
198 	unsigned int col_gpios = variant->col_gpios;
199 	unsigned int row_gpios = variant->row_gpios;
200 	struct stmpe *stmpe = keypad->stmpe;
201 	u8 pureg = stmpe->regs[STMPE_IDX_GPPUR_LSB];
202 	unsigned int pins = 0;
203 	unsigned int pu_pins = 0;
204 	int ret;
205 	int i;
206 
207 	/*
208 	 * Figure out which pins need to be set to the keypad alternate
209 	 * function.
210 	 *
211 	 * {cols,rows}_gpios are bitmasks of which pins on the chip can be used
212 	 * for the keypad.
213 	 *
214 	 * keypad->{cols,rows} are a bitmask of which pins (of the ones useable
215 	 * for the keypad) are used on the board.
216 	 */
217 
218 	for (i = 0; i < variant->max_cols; i++) {
219 		int num = __ffs(col_gpios);
220 
221 		if (keypad->cols & (1 << i)) {
222 			pins |= 1 << num;
223 			pu_pins |= 1 << num;
224 		}
225 
226 		col_gpios &= ~(1 << num);
227 	}
228 
229 	for (i = 0; i < variant->max_rows; i++) {
230 		int num = __ffs(row_gpios);
231 
232 		if (keypad->rows & (1 << i))
233 			pins |= 1 << num;
234 
235 		row_gpios &= ~(1 << num);
236 	}
237 
238 	ret = stmpe_set_altfunc(stmpe, pins, STMPE_BLOCK_KEYPAD);
239 	if (ret)
240 		return ret;
241 
242 	/*
243 	 * On STMPE24xx, set pin bias to pull-up on all keypad input
244 	 * pins (columns), this incidentally happen to be maximum 8 pins
245 	 * and placed at GPIO0-7 so only the LSB of the pull up register
246 	 * ever needs to be written.
247 	 */
248 	if (variant->set_pullup) {
249 		u8 val;
250 
251 		ret = stmpe_reg_read(stmpe, pureg);
252 		if (ret)
253 			return ret;
254 
255 		/* Do not touch unused pins, may be used for GPIO */
256 		val = ret & ~pu_pins;
257 		val |= pu_pins;
258 
259 		ret = stmpe_reg_write(stmpe, pureg, val);
260 	}
261 
262 	return 0;
263 }
264 
265 static int stmpe_keypad_chip_init(struct stmpe_keypad *keypad)
266 {
267 	const struct stmpe_keypad_variant *variant = keypad->variant;
268 	struct stmpe *stmpe = keypad->stmpe;
269 	int ret;
270 
271 	if (keypad->debounce_ms > STMPE_KEYPAD_MAX_DEBOUNCE)
272 		return -EINVAL;
273 
274 	if (keypad->scan_count > STMPE_KEYPAD_MAX_SCAN_COUNT)
275 		return -EINVAL;
276 
277 	ret = stmpe_enable(stmpe, STMPE_BLOCK_KEYPAD);
278 	if (ret < 0)
279 		return ret;
280 
281 	ret = stmpe_keypad_altfunc_init(keypad);
282 	if (ret < 0)
283 		return ret;
284 
285 	ret = stmpe_reg_write(stmpe, STMPE_KPC_COL, keypad->cols);
286 	if (ret < 0)
287 		return ret;
288 
289 	ret = stmpe_reg_write(stmpe, STMPE_KPC_ROW_LSB, keypad->rows);
290 	if (ret < 0)
291 		return ret;
292 
293 	if (variant->max_rows > 8) {
294 		ret = stmpe_set_bits(stmpe, STMPE_KPC_ROW_MSB,
295 				     STMPE_KPC_ROW_MSB_ROWS,
296 				     keypad->rows >> 8);
297 		if (ret < 0)
298 			return ret;
299 	}
300 
301 	ret = stmpe_set_bits(stmpe, STMPE_KPC_CTRL_MSB,
302 			     STMPE_KPC_CTRL_MSB_SCAN_COUNT,
303 			     keypad->scan_count << 4);
304 	if (ret < 0)
305 		return ret;
306 
307 	return stmpe_set_bits(stmpe, STMPE_KPC_CTRL_LSB,
308 			      STMPE_KPC_CTRL_LSB_SCAN |
309 			      STMPE_KPC_CTRL_LSB_DEBOUNCE,
310 			      STMPE_KPC_CTRL_LSB_SCAN |
311 			      (keypad->debounce_ms << 1));
312 }
313 
314 static void stmpe_keypad_fill_used_pins(struct stmpe_keypad *keypad,
315 					u32 used_rows, u32 used_cols)
316 {
317 	int row, col;
318 
319 	for (row = 0; row < used_rows; row++) {
320 		for (col = 0; col < used_cols; col++) {
321 			int code = MATRIX_SCAN_CODE(row, col,
322 						    STMPE_KEYPAD_ROW_SHIFT);
323 			if (keypad->keymap[code] != KEY_RESERVED) {
324 				keypad->rows |= 1 << row;
325 				keypad->cols |= 1 << col;
326 			}
327 		}
328 	}
329 }
330 
331 static int stmpe_keypad_probe(struct platform_device *pdev)
332 {
333 	struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
334 	struct device_node *np = pdev->dev.of_node;
335 	struct stmpe_keypad *keypad;
336 	struct input_dev *input;
337 	u32 rows;
338 	u32 cols;
339 	int error;
340 	int irq;
341 
342 	irq = platform_get_irq(pdev, 0);
343 	if (irq < 0)
344 		return irq;
345 
346 	keypad = devm_kzalloc(&pdev->dev, sizeof(struct stmpe_keypad),
347 			      GFP_KERNEL);
348 	if (!keypad)
349 		return -ENOMEM;
350 
351 	keypad->stmpe = stmpe;
352 	keypad->variant = &stmpe_keypad_variants[stmpe->partnum];
353 
354 	of_property_read_u32(np, "debounce-interval", &keypad->debounce_ms);
355 	of_property_read_u32(np, "st,scan-count", &keypad->scan_count);
356 	keypad->no_autorepeat = of_property_read_bool(np, "st,no-autorepeat");
357 
358 	input = devm_input_allocate_device(&pdev->dev);
359 	if (!input)
360 		return -ENOMEM;
361 
362 	input->name = "STMPE keypad";
363 	input->id.bustype = BUS_I2C;
364 	input->dev.parent = &pdev->dev;
365 
366 	error = matrix_keypad_parse_properties(&pdev->dev, &rows, &cols);
367 	if (error)
368 		return error;
369 
370 	error = matrix_keypad_build_keymap(NULL, NULL, rows, cols,
371 					   keypad->keymap, input);
372 	if (error)
373 		return error;
374 
375 	input_set_capability(input, EV_MSC, MSC_SCAN);
376 	if (!keypad->no_autorepeat)
377 		__set_bit(EV_REP, input->evbit);
378 
379 	stmpe_keypad_fill_used_pins(keypad, rows, cols);
380 
381 	keypad->input = input;
382 
383 	error = stmpe_keypad_chip_init(keypad);
384 	if (error < 0)
385 		return error;
386 
387 	error = devm_request_threaded_irq(&pdev->dev, irq,
388 					  NULL, stmpe_keypad_irq,
389 					  IRQF_ONESHOT, "stmpe-keypad", keypad);
390 	if (error) {
391 		dev_err(&pdev->dev, "unable to get irq: %d\n", error);
392 		return error;
393 	}
394 
395 	error = input_register_device(input);
396 	if (error) {
397 		dev_err(&pdev->dev,
398 			"unable to register input device: %d\n", error);
399 		return error;
400 	}
401 
402 	platform_set_drvdata(pdev, keypad);
403 
404 	return 0;
405 }
406 
407 static void stmpe_keypad_remove(struct platform_device *pdev)
408 {
409 	struct stmpe_keypad *keypad = platform_get_drvdata(pdev);
410 
411 	stmpe_disable(keypad->stmpe, STMPE_BLOCK_KEYPAD);
412 }
413 
414 static struct platform_driver stmpe_keypad_driver = {
415 	.driver.name	= "stmpe-keypad",
416 	.driver.owner	= THIS_MODULE,
417 	.probe		= stmpe_keypad_probe,
418 	.remove_new	= stmpe_keypad_remove,
419 };
420 module_platform_driver(stmpe_keypad_driver);
421 
422 MODULE_LICENSE("GPL v2");
423 MODULE_DESCRIPTION("STMPExxxx keypad driver");
424 MODULE_AUTHOR("Rabin Vincent <rabin.vincent@stericsson.com>");
425