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