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_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  * @num_data: number of data bytes
56  * @num_normal_data: number of normal keys' data bytes
57  * @max_cols: maximum number of columns supported
58  * @max_rows: maximum number of rows supported
59  * @col_gpios: bitmask of gpios which can be used for columns
60  * @row_gpios: bitmask of gpios which can be used for rows
61  */
62 struct stmpe_keypad_variant {
63 	bool		auto_increment;
64 	int		num_data;
65 	int		num_normal_data;
66 	int		max_cols;
67 	int		max_rows;
68 	unsigned int	col_gpios;
69 	unsigned int	row_gpios;
70 };
71 
72 static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
73 	[STMPE1601] = {
74 		.auto_increment		= true,
75 		.num_data		= 5,
76 		.num_normal_data	= 3,
77 		.max_cols		= 8,
78 		.max_rows		= 8,
79 		.col_gpios		= 0x000ff,	/* GPIO 0 - 7 */
80 		.row_gpios		= 0x0ff00,	/* GPIO 8 - 15 */
81 	},
82 	[STMPE2401] = {
83 		.auto_increment		= false,
84 		.num_data		= 3,
85 		.num_normal_data	= 2,
86 		.max_cols		= 8,
87 		.max_rows		= 12,
88 		.col_gpios		= 0x0000ff,	/* GPIO 0 - 7*/
89 		.row_gpios		= 0x1fef00,	/* GPIO 8-14, 16-20 */
90 	},
91 	[STMPE2403] = {
92 		.auto_increment		= true,
93 		.num_data		= 5,
94 		.num_normal_data	= 3,
95 		.max_cols		= 8,
96 		.max_rows		= 12,
97 		.col_gpios		= 0x0000ff,	/* GPIO 0 - 7*/
98 		.row_gpios		= 0x1fef00,	/* GPIO 8-14, 16-20 */
99 	},
100 };
101 
102 struct stmpe_keypad {
103 	struct stmpe *stmpe;
104 	struct input_dev *input;
105 	const struct stmpe_keypad_variant *variant;
106 	const struct stmpe_keypad_platform_data *plat;
107 
108 	unsigned int rows;
109 	unsigned int cols;
110 
111 	unsigned short keymap[STMPE_KEYPAD_KEYMAP_SIZE];
112 };
113 
114 static int stmpe_keypad_read_data(struct stmpe_keypad *keypad, u8 *data)
115 {
116 	const struct stmpe_keypad_variant *variant = keypad->variant;
117 	struct stmpe *stmpe = keypad->stmpe;
118 	int ret;
119 	int i;
120 
121 	if (variant->auto_increment)
122 		return stmpe_block_read(stmpe, STMPE_KPC_DATA_BYTE0,
123 					variant->num_data, data);
124 
125 	for (i = 0; i < variant->num_data; i++) {
126 		ret = stmpe_reg_read(stmpe, STMPE_KPC_DATA_BYTE0 + i);
127 		if (ret < 0)
128 			return ret;
129 
130 		data[i] = ret;
131 	}
132 
133 	return 0;
134 }
135 
136 static irqreturn_t stmpe_keypad_irq(int irq, void *dev)
137 {
138 	struct stmpe_keypad *keypad = dev;
139 	struct input_dev *input = keypad->input;
140 	const struct stmpe_keypad_variant *variant = keypad->variant;
141 	u8 fifo[variant->num_data];
142 	int ret;
143 	int i;
144 
145 	ret = stmpe_keypad_read_data(keypad, fifo);
146 	if (ret < 0)
147 		return IRQ_NONE;
148 
149 	for (i = 0; i < variant->num_normal_data; i++) {
150 		u8 data = fifo[i];
151 		int row = (data & STMPE_KPC_DATA_ROW) >> 3;
152 		int col = data & STMPE_KPC_DATA_COL;
153 		int code = MATRIX_SCAN_CODE(row, col, STMPE_KEYPAD_ROW_SHIFT);
154 		bool up = data & STMPE_KPC_DATA_UP;
155 
156 		if ((data & STMPE_KPC_DATA_NOKEY_MASK)
157 			== STMPE_KPC_DATA_NOKEY_MASK)
158 			continue;
159 
160 		input_event(input, EV_MSC, MSC_SCAN, code);
161 		input_report_key(input, keypad->keymap[code], !up);
162 		input_sync(input);
163 	}
164 
165 	return IRQ_HANDLED;
166 }
167 
168 static int stmpe_keypad_altfunc_init(struct stmpe_keypad *keypad)
169 {
170 	const struct stmpe_keypad_variant *variant = keypad->variant;
171 	unsigned int col_gpios = variant->col_gpios;
172 	unsigned int row_gpios = variant->row_gpios;
173 	struct stmpe *stmpe = keypad->stmpe;
174 	unsigned int pins = 0;
175 	int i;
176 
177 	/*
178 	 * Figure out which pins need to be set to the keypad alternate
179 	 * function.
180 	 *
181 	 * {cols,rows}_gpios are bitmasks of which pins on the chip can be used
182 	 * for the keypad.
183 	 *
184 	 * keypad->{cols,rows} are a bitmask of which pins (of the ones useable
185 	 * for the keypad) are used on the board.
186 	 */
187 
188 	for (i = 0; i < variant->max_cols; i++) {
189 		int num = __ffs(col_gpios);
190 
191 		if (keypad->cols & (1 << i))
192 			pins |= 1 << num;
193 
194 		col_gpios &= ~(1 << num);
195 	}
196 
197 	for (i = 0; i < variant->max_rows; i++) {
198 		int num = __ffs(row_gpios);
199 
200 		if (keypad->rows & (1 << i))
201 			pins |= 1 << num;
202 
203 		row_gpios &= ~(1 << num);
204 	}
205 
206 	return stmpe_set_altfunc(stmpe, pins, STMPE_BLOCK_KEYPAD);
207 }
208 
209 static int stmpe_keypad_chip_init(struct stmpe_keypad *keypad)
210 {
211 	const struct stmpe_keypad_platform_data *plat = keypad->plat;
212 	const struct stmpe_keypad_variant *variant = keypad->variant;
213 	struct stmpe *stmpe = keypad->stmpe;
214 	int ret;
215 
216 	if (plat->debounce_ms > STMPE_KEYPAD_MAX_DEBOUNCE)
217 		return -EINVAL;
218 
219 	if (plat->scan_count > STMPE_KEYPAD_MAX_SCAN_COUNT)
220 		return -EINVAL;
221 
222 	ret = stmpe_enable(stmpe, STMPE_BLOCK_KEYPAD);
223 	if (ret < 0)
224 		return ret;
225 
226 	ret = stmpe_keypad_altfunc_init(keypad);
227 	if (ret < 0)
228 		return ret;
229 
230 	ret = stmpe_reg_write(stmpe, STMPE_KPC_COL, keypad->cols);
231 	if (ret < 0)
232 		return ret;
233 
234 	ret = stmpe_reg_write(stmpe, STMPE_KPC_ROW_LSB, keypad->rows);
235 	if (ret < 0)
236 		return ret;
237 
238 	if (variant->max_rows > 8) {
239 		ret = stmpe_set_bits(stmpe, STMPE_KPC_ROW_MSB,
240 				     STMPE_KPC_ROW_MSB_ROWS,
241 				     keypad->rows >> 8);
242 		if (ret < 0)
243 			return ret;
244 	}
245 
246 	ret = stmpe_set_bits(stmpe, STMPE_KPC_CTRL_MSB,
247 			     STMPE_KPC_CTRL_MSB_SCAN_COUNT,
248 			     plat->scan_count << 4);
249 	if (ret < 0)
250 		return ret;
251 
252 	return stmpe_set_bits(stmpe, STMPE_KPC_CTRL_LSB,
253 			      STMPE_KPC_CTRL_LSB_SCAN |
254 			      STMPE_KPC_CTRL_LSB_DEBOUNCE,
255 			      STMPE_KPC_CTRL_LSB_SCAN |
256 			      (plat->debounce_ms << 1));
257 }
258 
259 static void stmpe_keypad_fill_used_pins(struct stmpe_keypad *keypad)
260 {
261 	int row, col;
262 
263 	for (row = 0; row < STMPE_KEYPAD_MAX_ROWS; row++) {
264 		for (col = 0; col < STMPE_KEYPAD_MAX_COLS; col++) {
265 			int code = MATRIX_SCAN_CODE(row, col,
266 						STMPE_KEYPAD_ROW_SHIFT);
267 			if (keypad->keymap[code] != KEY_RESERVED) {
268 				keypad->rows |= 1 << row;
269 				keypad->cols |= 1 << col;
270 			}
271 		}
272 	}
273 }
274 
275 #ifdef CONFIG_OF
276 static const struct stmpe_keypad_platform_data *
277 stmpe_keypad_of_probe(struct device *dev)
278 {
279 	struct device_node *np = dev->of_node;
280 	struct stmpe_keypad_platform_data *plat;
281 
282 	if (!np)
283 		return ERR_PTR(-ENODEV);
284 
285 	plat = devm_kzalloc(dev, sizeof(*plat), GFP_KERNEL);
286 	if (!plat)
287 		return ERR_PTR(-ENOMEM);
288 
289 	of_property_read_u32(np, "debounce-interval", &plat->debounce_ms);
290 	of_property_read_u32(np, "st,scan-count", &plat->scan_count);
291 
292 	plat->no_autorepeat = of_property_read_bool(np, "st,no-autorepeat");
293 
294 	return plat;
295 }
296 #else
297 static inline const struct stmpe_keypad_platform_data *
298 stmpe_keypad_of_probe(struct device *dev)
299 {
300 	return ERR_PTR(-EINVAL);
301 }
302 #endif
303 
304 static int stmpe_keypad_probe(struct platform_device *pdev)
305 {
306 	struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
307 	const struct stmpe_keypad_platform_data *plat;
308 	struct stmpe_keypad *keypad;
309 	struct input_dev *input;
310 	int error;
311 	int irq;
312 
313 	plat = stmpe->pdata->keypad;
314 	if (!plat) {
315 		plat = stmpe_keypad_of_probe(&pdev->dev);
316 		if (IS_ERR(plat))
317 			return PTR_ERR(plat);
318 	}
319 
320 	irq = platform_get_irq(pdev, 0);
321 	if (irq < 0)
322 		return irq;
323 
324 	keypad = devm_kzalloc(&pdev->dev, sizeof(struct stmpe_keypad),
325 			      GFP_KERNEL);
326 	if (!keypad)
327 		return -ENOMEM;
328 
329 	input = devm_input_allocate_device(&pdev->dev);
330 	if (!input)
331 		return -ENOMEM;
332 
333 	input->name = "STMPE keypad";
334 	input->id.bustype = BUS_I2C;
335 	input->dev.parent = &pdev->dev;
336 
337 	error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
338 					   STMPE_KEYPAD_MAX_ROWS,
339 					   STMPE_KEYPAD_MAX_COLS,
340 					   keypad->keymap, input);
341 	if (error)
342 		return error;
343 
344 	input_set_capability(input, EV_MSC, MSC_SCAN);
345 	if (!plat->no_autorepeat)
346 		__set_bit(EV_REP, input->evbit);
347 
348 	stmpe_keypad_fill_used_pins(keypad);
349 
350 	keypad->stmpe = stmpe;
351 	keypad->plat = plat;
352 	keypad->input = input;
353 	keypad->variant = &stmpe_keypad_variants[stmpe->partnum];
354 
355 	error = stmpe_keypad_chip_init(keypad);
356 	if (error < 0)
357 		return error;
358 
359 	error = devm_request_threaded_irq(&pdev->dev, irq,
360 					  NULL, stmpe_keypad_irq,
361 					  IRQF_ONESHOT, "stmpe-keypad", keypad);
362 	if (error) {
363 		dev_err(&pdev->dev, "unable to get irq: %d\n", error);
364 		return error;
365 	}
366 
367 	error = input_register_device(input);
368 	if (error) {
369 		dev_err(&pdev->dev,
370 			"unable to register input device: %d\n", error);
371 		return error;
372 	}
373 
374 	platform_set_drvdata(pdev, keypad);
375 
376 	return 0;
377 }
378 
379 static int stmpe_keypad_remove(struct platform_device *pdev)
380 {
381 	struct stmpe_keypad *keypad = platform_get_drvdata(pdev);
382 
383 	stmpe_disable(keypad->stmpe, STMPE_BLOCK_KEYPAD);
384 
385 	return 0;
386 }
387 
388 static struct platform_driver stmpe_keypad_driver = {
389 	.driver.name	= "stmpe-keypad",
390 	.driver.owner	= THIS_MODULE,
391 	.probe		= stmpe_keypad_probe,
392 	.remove		= stmpe_keypad_remove,
393 };
394 module_platform_driver(stmpe_keypad_driver);
395 
396 MODULE_LICENSE("GPL v2");
397 MODULE_DESCRIPTION("STMPExxxx keypad driver");
398 MODULE_AUTHOR("Rabin Vincent <rabin.vincent@stericsson.com>");
399