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/platform_device.h>
13 #include <linux/input/matrix_keypad.h>
14 #include <linux/mfd/stmpe.h>
15 
16 /* These are at the same addresses in all STMPE variants */
17 #define STMPE_KPC_COL			0x60
18 #define STMPE_KPC_ROW_MSB		0x61
19 #define STMPE_KPC_ROW_LSB		0x62
20 #define STMPE_KPC_CTRL_MSB		0x63
21 #define STMPE_KPC_CTRL_LSB		0x64
22 #define STMPE_KPC_COMBI_KEY_0		0x65
23 #define STMPE_KPC_COMBI_KEY_1		0x66
24 #define STMPE_KPC_COMBI_KEY_2		0x67
25 #define STMPE_KPC_DATA_BYTE0		0x68
26 #define STMPE_KPC_DATA_BYTE1		0x69
27 #define STMPE_KPC_DATA_BYTE2		0x6a
28 #define STMPE_KPC_DATA_BYTE3		0x6b
29 #define STMPE_KPC_DATA_BYTE4		0x6c
30 
31 #define STMPE_KPC_CTRL_LSB_SCAN		(0x1 << 0)
32 #define STMPE_KPC_CTRL_LSB_DEBOUNCE	(0x7f << 1)
33 #define STMPE_KPC_CTRL_MSB_SCAN_COUNT	(0xf << 4)
34 
35 #define STMPE_KPC_ROW_MSB_ROWS		0xff
36 
37 #define STMPE_KPC_DATA_UP		(0x1 << 7)
38 #define STMPE_KPC_DATA_ROW		(0xf << 3)
39 #define STMPE_KPC_DATA_COL		(0x7 << 0)
40 #define STMPE_KPC_DATA_NOKEY_MASK	0x78
41 
42 #define STMPE_KEYPAD_MAX_DEBOUNCE	127
43 #define STMPE_KEYPAD_MAX_SCAN_COUNT	15
44 
45 #define STMPE_KEYPAD_MAX_ROWS		8
46 #define STMPE_KEYPAD_MAX_COLS		8
47 #define STMPE_KEYPAD_ROW_SHIFT		3
48 #define STMPE_KEYPAD_KEYMAP_MAX_SIZE \
49 	(STMPE_KEYPAD_MAX_ROWS * STMPE_KEYPAD_MAX_COLS)
50 
51 
52 #define STMPE1601_NUM_DATA	5
53 #define STMPE2401_NUM_DATA	3
54 #define STMPE2403_NUM_DATA	5
55 
56 /* Make sure it covers all cases above */
57 #define MAX_NUM_DATA		5
58 
59 /**
60  * struct stmpe_keypad_variant - model-specific attributes
61  * @auto_increment: whether the KPC_DATA_BYTE register address
62  *		    auto-increments on multiple read
63  * @set_pullup: whether the pins need to have their pull-ups set
64  * @num_data: number of data bytes
65  * @num_normal_data: number of normal keys' data bytes
66  * @max_cols: maximum number of columns supported
67  * @max_rows: maximum number of rows supported
68  * @col_gpios: bitmask of gpios which can be used for columns
69  * @row_gpios: bitmask of gpios which can be used for rows
70  */
71 struct stmpe_keypad_variant {
72 	bool		auto_increment;
73 	bool		set_pullup;
74 	int		num_data;
75 	int		num_normal_data;
76 	int		max_cols;
77 	int		max_rows;
78 	unsigned int	col_gpios;
79 	unsigned int	row_gpios;
80 };
81 
82 static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
83 	[STMPE1601] = {
84 		.auto_increment		= true,
85 		.num_data		= STMPE1601_NUM_DATA,
86 		.num_normal_data	= 3,
87 		.max_cols		= 8,
88 		.max_rows		= 8,
89 		.col_gpios		= 0x000ff,	/* GPIO 0 - 7 */
90 		.row_gpios		= 0x0ff00,	/* GPIO 8 - 15 */
91 	},
92 	[STMPE2401] = {
93 		.auto_increment		= false,
94 		.set_pullup		= true,
95 		.num_data		= STMPE2401_NUM_DATA,
96 		.num_normal_data	= 2,
97 		.max_cols		= 8,
98 		.max_rows		= 12,
99 		.col_gpios		= 0x0000ff,	/* GPIO 0 - 7*/
100 		.row_gpios		= 0x1f7f00,	/* GPIO 8-14, 16-20 */
101 	},
102 	[STMPE2403] = {
103 		.auto_increment		= true,
104 		.set_pullup		= true,
105 		.num_data		= STMPE2403_NUM_DATA,
106 		.num_normal_data	= 3,
107 		.max_cols		= 8,
108 		.max_rows		= 12,
109 		.col_gpios		= 0x0000ff,	/* GPIO 0 - 7*/
110 		.row_gpios		= 0x1fef00,	/* GPIO 8-14, 16-20 */
111 	},
112 };
113 
114 /**
115  * struct stmpe_keypad - STMPE keypad state container
116  * @stmpe: pointer to parent STMPE device
117  * @input: spawned input device
118  * @variant: STMPE variant
119  * @debounce_ms: debounce interval, in ms.  Maximum is
120  *		 %STMPE_KEYPAD_MAX_DEBOUNCE.
121  * @scan_count: number of key scanning cycles to confirm key data.
122  *		Maximum is %STMPE_KEYPAD_MAX_SCAN_COUNT.
123  * @no_autorepeat: disable key autorepeat
124  * @rows: bitmask for the rows
125  * @cols: bitmask for the columns
126  * @keymap: the keymap
127  */
128 struct stmpe_keypad {
129 	struct stmpe *stmpe;
130 	struct input_dev *input;
131 	const struct stmpe_keypad_variant *variant;
132 	unsigned int debounce_ms;
133 	unsigned int scan_count;
134 	bool no_autorepeat;
135 	unsigned int rows;
136 	unsigned int cols;
137 	unsigned short keymap[STMPE_KEYPAD_KEYMAP_MAX_SIZE];
138 };
139 
140 static int stmpe_keypad_read_data(struct stmpe_keypad *keypad, u8 *data)
141 {
142 	const struct stmpe_keypad_variant *variant = keypad->variant;
143 	struct stmpe *stmpe = keypad->stmpe;
144 	int ret;
145 	int i;
146 
147 	if (variant->auto_increment)
148 		return stmpe_block_read(stmpe, STMPE_KPC_DATA_BYTE0,
149 					variant->num_data, data);
150 
151 	for (i = 0; i < variant->num_data; i++) {
152 		ret = stmpe_reg_read(stmpe, STMPE_KPC_DATA_BYTE0 + i);
153 		if (ret < 0)
154 			return ret;
155 
156 		data[i] = ret;
157 	}
158 
159 	return 0;
160 }
161 
162 static irqreturn_t stmpe_keypad_irq(int irq, void *dev)
163 {
164 	struct stmpe_keypad *keypad = dev;
165 	struct input_dev *input = keypad->input;
166 	const struct stmpe_keypad_variant *variant = keypad->variant;
167 	u8 fifo[MAX_NUM_DATA];
168 	int ret;
169 	int i;
170 
171 	ret = stmpe_keypad_read_data(keypad, fifo);
172 	if (ret < 0)
173 		return IRQ_NONE;
174 
175 	for (i = 0; i < variant->num_normal_data; i++) {
176 		u8 data = fifo[i];
177 		int row = (data & STMPE_KPC_DATA_ROW) >> 3;
178 		int col = data & STMPE_KPC_DATA_COL;
179 		int code = MATRIX_SCAN_CODE(row, col, STMPE_KEYPAD_ROW_SHIFT);
180 		bool up = data & STMPE_KPC_DATA_UP;
181 
182 		if ((data & STMPE_KPC_DATA_NOKEY_MASK)
183 			== STMPE_KPC_DATA_NOKEY_MASK)
184 			continue;
185 
186 		input_event(input, EV_MSC, MSC_SCAN, code);
187 		input_report_key(input, keypad->keymap[code], !up);
188 		input_sync(input);
189 	}
190 
191 	return IRQ_HANDLED;
192 }
193 
194 static int stmpe_keypad_altfunc_init(struct stmpe_keypad *keypad)
195 {
196 	const struct stmpe_keypad_variant *variant = keypad->variant;
197 	unsigned int col_gpios = variant->col_gpios;
198 	unsigned int row_gpios = variant->row_gpios;
199 	struct stmpe *stmpe = keypad->stmpe;
200 	u8 pureg = stmpe->regs[STMPE_IDX_GPPUR_LSB];
201 	unsigned int pins = 0;
202 	unsigned int pu_pins = 0;
203 	int ret;
204 	int i;
205 
206 	/*
207 	 * Figure out which pins need to be set to the keypad alternate
208 	 * function.
209 	 *
210 	 * {cols,rows}_gpios are bitmasks of which pins on the chip can be used
211 	 * for the keypad.
212 	 *
213 	 * keypad->{cols,rows} are a bitmask of which pins (of the ones useable
214 	 * for the keypad) are used on the board.
215 	 */
216 
217 	for (i = 0; i < variant->max_cols; i++) {
218 		int num = __ffs(col_gpios);
219 
220 		if (keypad->cols & (1 << i)) {
221 			pins |= 1 << num;
222 			pu_pins |= 1 << num;
223 		}
224 
225 		col_gpios &= ~(1 << num);
226 	}
227 
228 	for (i = 0; i < variant->max_rows; i++) {
229 		int num = __ffs(row_gpios);
230 
231 		if (keypad->rows & (1 << i))
232 			pins |= 1 << num;
233 
234 		row_gpios &= ~(1 << num);
235 	}
236 
237 	ret = stmpe_set_altfunc(stmpe, pins, STMPE_BLOCK_KEYPAD);
238 	if (ret)
239 		return ret;
240 
241 	/*
242 	 * On STMPE24xx, set pin bias to pull-up on all keypad input
243 	 * pins (columns), this incidentally happen to be maximum 8 pins
244 	 * and placed at GPIO0-7 so only the LSB of the pull up register
245 	 * ever needs to be written.
246 	 */
247 	if (variant->set_pullup) {
248 		u8 val;
249 
250 		ret = stmpe_reg_read(stmpe, pureg);
251 		if (ret)
252 			return ret;
253 
254 		/* Do not touch unused pins, may be used for GPIO */
255 		val = ret & ~pu_pins;
256 		val |= pu_pins;
257 
258 		ret = stmpe_reg_write(stmpe, pureg, val);
259 	}
260 
261 	return 0;
262 }
263 
264 static int stmpe_keypad_chip_init(struct stmpe_keypad *keypad)
265 {
266 	const struct stmpe_keypad_variant *variant = keypad->variant;
267 	struct stmpe *stmpe = keypad->stmpe;
268 	int ret;
269 
270 	if (keypad->debounce_ms > STMPE_KEYPAD_MAX_DEBOUNCE)
271 		return -EINVAL;
272 
273 	if (keypad->scan_count > STMPE_KEYPAD_MAX_SCAN_COUNT)
274 		return -EINVAL;
275 
276 	ret = stmpe_enable(stmpe, STMPE_BLOCK_KEYPAD);
277 	if (ret < 0)
278 		return ret;
279 
280 	ret = stmpe_keypad_altfunc_init(keypad);
281 	if (ret < 0)
282 		return ret;
283 
284 	ret = stmpe_reg_write(stmpe, STMPE_KPC_COL, keypad->cols);
285 	if (ret < 0)
286 		return ret;
287 
288 	ret = stmpe_reg_write(stmpe, STMPE_KPC_ROW_LSB, keypad->rows);
289 	if (ret < 0)
290 		return ret;
291 
292 	if (variant->max_rows > 8) {
293 		ret = stmpe_set_bits(stmpe, STMPE_KPC_ROW_MSB,
294 				     STMPE_KPC_ROW_MSB_ROWS,
295 				     keypad->rows >> 8);
296 		if (ret < 0)
297 			return ret;
298 	}
299 
300 	ret = stmpe_set_bits(stmpe, STMPE_KPC_CTRL_MSB,
301 			     STMPE_KPC_CTRL_MSB_SCAN_COUNT,
302 			     keypad->scan_count << 4);
303 	if (ret < 0)
304 		return ret;
305 
306 	return stmpe_set_bits(stmpe, STMPE_KPC_CTRL_LSB,
307 			      STMPE_KPC_CTRL_LSB_SCAN |
308 			      STMPE_KPC_CTRL_LSB_DEBOUNCE,
309 			      STMPE_KPC_CTRL_LSB_SCAN |
310 			      (keypad->debounce_ms << 1));
311 }
312 
313 static void stmpe_keypad_fill_used_pins(struct stmpe_keypad *keypad,
314 					u32 used_rows, u32 used_cols)
315 {
316 	int row, col;
317 
318 	for (row = 0; row < used_rows; row++) {
319 		for (col = 0; col < used_cols; col++) {
320 			int code = MATRIX_SCAN_CODE(row, col,
321 						    STMPE_KEYPAD_ROW_SHIFT);
322 			if (keypad->keymap[code] != KEY_RESERVED) {
323 				keypad->rows |= 1 << row;
324 				keypad->cols |= 1 << col;
325 			}
326 		}
327 	}
328 }
329 
330 static int stmpe_keypad_probe(struct platform_device *pdev)
331 {
332 	struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
333 	struct device_node *np = pdev->dev.of_node;
334 	struct stmpe_keypad *keypad;
335 	struct input_dev *input;
336 	u32 rows;
337 	u32 cols;
338 	int error;
339 	int irq;
340 
341 	irq = platform_get_irq(pdev, 0);
342 	if (irq < 0)
343 		return irq;
344 
345 	keypad = devm_kzalloc(&pdev->dev, sizeof(struct stmpe_keypad),
346 			      GFP_KERNEL);
347 	if (!keypad)
348 		return -ENOMEM;
349 
350 	keypad->stmpe = stmpe;
351 	keypad->variant = &stmpe_keypad_variants[stmpe->partnum];
352 
353 	of_property_read_u32(np, "debounce-interval", &keypad->debounce_ms);
354 	of_property_read_u32(np, "st,scan-count", &keypad->scan_count);
355 	keypad->no_autorepeat = of_property_read_bool(np, "st,no-autorepeat");
356 
357 	input = devm_input_allocate_device(&pdev->dev);
358 	if (!input)
359 		return -ENOMEM;
360 
361 	input->name = "STMPE keypad";
362 	input->id.bustype = BUS_I2C;
363 	input->dev.parent = &pdev->dev;
364 
365 	error = matrix_keypad_parse_properties(&pdev->dev, &rows, &cols);
366 	if (error)
367 		return error;
368 
369 	error = matrix_keypad_build_keymap(NULL, NULL, rows, cols,
370 					   keypad->keymap, input);
371 	if (error)
372 		return error;
373 
374 	input_set_capability(input, EV_MSC, MSC_SCAN);
375 	if (!keypad->no_autorepeat)
376 		__set_bit(EV_REP, input->evbit);
377 
378 	stmpe_keypad_fill_used_pins(keypad, rows, cols);
379 
380 	keypad->input = input;
381 
382 	error = stmpe_keypad_chip_init(keypad);
383 	if (error < 0)
384 		return error;
385 
386 	error = devm_request_threaded_irq(&pdev->dev, irq,
387 					  NULL, stmpe_keypad_irq,
388 					  IRQF_ONESHOT, "stmpe-keypad", keypad);
389 	if (error) {
390 		dev_err(&pdev->dev, "unable to get irq: %d\n", error);
391 		return error;
392 	}
393 
394 	error = input_register_device(input);
395 	if (error) {
396 		dev_err(&pdev->dev,
397 			"unable to register input device: %d\n", error);
398 		return error;
399 	}
400 
401 	platform_set_drvdata(pdev, keypad);
402 
403 	return 0;
404 }
405 
406 static int stmpe_keypad_remove(struct platform_device *pdev)
407 {
408 	struct stmpe_keypad *keypad = platform_get_drvdata(pdev);
409 
410 	stmpe_disable(keypad->stmpe, STMPE_BLOCK_KEYPAD);
411 
412 	return 0;
413 }
414 
415 static struct platform_driver stmpe_keypad_driver = {
416 	.driver.name	= "stmpe-keypad",
417 	.driver.owner	= THIS_MODULE,
418 	.probe		= stmpe_keypad_probe,
419 	.remove		= stmpe_keypad_remove,
420 };
421 module_platform_driver(stmpe_keypad_driver);
422 
423 MODULE_LICENSE("GPL v2");
424 MODULE_DESCRIPTION("STMPExxxx keypad driver");
425 MODULE_AUTHOR("Rabin Vincent <rabin.vincent@stericsson.com>");
426