1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * twl4030_keypad.c - driver for 8x8 keypad controller in twl4030 chips
4  *
5  * Copyright (C) 2007 Texas Instruments, Inc.
6  * Copyright (C) 2008 Nokia Corporation
7  *
8  * Code re-written for 2430SDP by:
9  * Syed Mohammed Khasim <x0khasim@ti.com>
10  *
11  * Initial Code:
12  * Manjunatha G K <manjugk@ti.com>
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/interrupt.h>
18 #include <linux/input.h>
19 #include <linux/platform_device.h>
20 #include <linux/mfd/twl.h>
21 #include <linux/slab.h>
22 #include <linux/of.h>
23 
24 /*
25  * The TWL4030 family chips include a keypad controller that supports
26  * up to an 8x8 switch matrix.  The controller can issue system wakeup
27  * events, since it uses only the always-on 32KiHz oscillator, and has
28  * an internal state machine that decodes pressed keys, including
29  * multi-key combinations.
30  *
31  * This driver lets boards define what keycodes they wish to report for
32  * which scancodes, as part of the "struct twl4030_keypad_data" used in
33  * the probe() routine.
34  *
35  * See the TPS65950 documentation; that's the general availability
36  * version of the TWL5030 second generation part.
37  */
38 #define TWL4030_MAX_ROWS	8	/* TWL4030 hard limit */
39 #define TWL4030_MAX_COLS	8
40 /*
41  * Note that we add space for an extra column so that we can handle
42  * row lines connected to the gnd (see twl4030_col_xlate()).
43  */
44 #define TWL4030_ROW_SHIFT	4
45 #define TWL4030_KEYMAP_SIZE	(TWL4030_MAX_ROWS << TWL4030_ROW_SHIFT)
46 
47 struct twl4030_keypad {
48 	unsigned short	keymap[TWL4030_KEYMAP_SIZE];
49 	u16		kp_state[TWL4030_MAX_ROWS];
50 	bool		autorepeat;
51 	unsigned int	n_rows;
52 	unsigned int	n_cols;
53 	int		irq;
54 
55 	struct device *dbg_dev;
56 	struct input_dev *input;
57 };
58 
59 /*----------------------------------------------------------------------*/
60 
61 /* arbitrary prescaler value 0..7 */
62 #define PTV_PRESCALER			4
63 
64 /* Register Offsets */
65 #define KEYP_CTRL			0x00
66 #define KEYP_DEB			0x01
67 #define KEYP_LONG_KEY			0x02
68 #define KEYP_LK_PTV			0x03
69 #define KEYP_TIMEOUT_L			0x04
70 #define KEYP_TIMEOUT_H			0x05
71 #define KEYP_KBC			0x06
72 #define KEYP_KBR			0x07
73 #define KEYP_SMS			0x08
74 #define KEYP_FULL_CODE_7_0		0x09	/* row 0 column status */
75 #define KEYP_FULL_CODE_15_8		0x0a	/* ... row 1 ... */
76 #define KEYP_FULL_CODE_23_16		0x0b
77 #define KEYP_FULL_CODE_31_24		0x0c
78 #define KEYP_FULL_CODE_39_32		0x0d
79 #define KEYP_FULL_CODE_47_40		0x0e
80 #define KEYP_FULL_CODE_55_48		0x0f
81 #define KEYP_FULL_CODE_63_56		0x10
82 #define KEYP_ISR1			0x11
83 #define KEYP_IMR1			0x12
84 #define KEYP_ISR2			0x13
85 #define KEYP_IMR2			0x14
86 #define KEYP_SIR			0x15
87 #define KEYP_EDR			0x16	/* edge triggers */
88 #define KEYP_SIH_CTRL			0x17
89 
90 /* KEYP_CTRL_REG Fields */
91 #define KEYP_CTRL_SOFT_NRST		BIT(0)
92 #define KEYP_CTRL_SOFTMODEN		BIT(1)
93 #define KEYP_CTRL_LK_EN			BIT(2)
94 #define KEYP_CTRL_TOE_EN		BIT(3)
95 #define KEYP_CTRL_TOLE_EN		BIT(4)
96 #define KEYP_CTRL_RP_EN			BIT(5)
97 #define KEYP_CTRL_KBD_ON		BIT(6)
98 
99 /* KEYP_DEB, KEYP_LONG_KEY, KEYP_TIMEOUT_x*/
100 #define KEYP_PERIOD_US(t, prescale)	((t) / (31 << ((prescale) + 1)) - 1)
101 
102 /* KEYP_LK_PTV_REG Fields */
103 #define KEYP_LK_PTV_PTV_SHIFT		5
104 
105 /* KEYP_{IMR,ISR,SIR} Fields */
106 #define KEYP_IMR1_MIS			BIT(3)
107 #define KEYP_IMR1_TO			BIT(2)
108 #define KEYP_IMR1_LK			BIT(1)
109 #define KEYP_IMR1_KP			BIT(0)
110 
111 /* KEYP_EDR Fields */
112 #define KEYP_EDR_KP_FALLING		0x01
113 #define KEYP_EDR_KP_RISING		0x02
114 #define KEYP_EDR_KP_BOTH		0x03
115 #define KEYP_EDR_LK_FALLING		0x04
116 #define KEYP_EDR_LK_RISING		0x08
117 #define KEYP_EDR_TO_FALLING		0x10
118 #define KEYP_EDR_TO_RISING		0x20
119 #define KEYP_EDR_MIS_FALLING		0x40
120 #define KEYP_EDR_MIS_RISING		0x80
121 
122 
123 /*----------------------------------------------------------------------*/
124 
125 static int twl4030_kpread(struct twl4030_keypad *kp,
126 		u8 *data, u32 reg, u8 num_bytes)
127 {
128 	int ret = twl_i2c_read(TWL4030_MODULE_KEYPAD, data, reg, num_bytes);
129 
130 	if (ret < 0)
131 		dev_warn(kp->dbg_dev,
132 			"Couldn't read TWL4030: %X - ret %d[%x]\n",
133 			 reg, ret, ret);
134 
135 	return ret;
136 }
137 
138 static int twl4030_kpwrite_u8(struct twl4030_keypad *kp, u8 data, u32 reg)
139 {
140 	int ret = twl_i2c_write_u8(TWL4030_MODULE_KEYPAD, data, reg);
141 
142 	if (ret < 0)
143 		dev_warn(kp->dbg_dev,
144 			"Could not write TWL4030: %X - ret %d[%x]\n",
145 			 reg, ret, ret);
146 
147 	return ret;
148 }
149 
150 static inline u16 twl4030_col_xlate(struct twl4030_keypad *kp, u8 col)
151 {
152 	/*
153 	 * If all bits in a row are active for all columns then
154 	 * we have that row line connected to gnd. Mark this
155 	 * key on as if it was on matrix position n_cols (i.e.
156 	 * one higher than the size of the matrix).
157 	 */
158 	if (col == 0xFF)
159 		return 1 << kp->n_cols;
160 	else
161 		return col & ((1 << kp->n_cols) - 1);
162 }
163 
164 static int twl4030_read_kp_matrix_state(struct twl4030_keypad *kp, u16 *state)
165 {
166 	u8 new_state[TWL4030_MAX_ROWS];
167 	int row;
168 	int ret = twl4030_kpread(kp, new_state,
169 				 KEYP_FULL_CODE_7_0, kp->n_rows);
170 	if (ret >= 0)
171 		for (row = 0; row < kp->n_rows; row++)
172 			state[row] = twl4030_col_xlate(kp, new_state[row]);
173 
174 	return ret;
175 }
176 
177 static bool twl4030_is_in_ghost_state(struct twl4030_keypad *kp, u16 *key_state)
178 {
179 	int i;
180 	u16 check = 0;
181 
182 	for (i = 0; i < kp->n_rows; i++) {
183 		u16 col = key_state[i];
184 
185 		if ((col & check) && hweight16(col) > 1)
186 			return true;
187 
188 		check |= col;
189 	}
190 
191 	return false;
192 }
193 
194 static void twl4030_kp_scan(struct twl4030_keypad *kp, bool release_all)
195 {
196 	struct input_dev *input = kp->input;
197 	u16 new_state[TWL4030_MAX_ROWS];
198 	int col, row;
199 
200 	if (release_all) {
201 		memset(new_state, 0, sizeof(new_state));
202 	} else {
203 		/* check for any changes */
204 		int ret = twl4030_read_kp_matrix_state(kp, new_state);
205 
206 		if (ret < 0)	/* panic ... */
207 			return;
208 
209 		if (twl4030_is_in_ghost_state(kp, new_state))
210 			return;
211 	}
212 
213 	/* check for changes and print those */
214 	for (row = 0; row < kp->n_rows; row++) {
215 		int changed = new_state[row] ^ kp->kp_state[row];
216 
217 		if (!changed)
218 			continue;
219 
220 		/* Extra column handles "all gnd" rows */
221 		for (col = 0; col < kp->n_cols + 1; col++) {
222 			int code;
223 
224 			if (!(changed & (1 << col)))
225 				continue;
226 
227 			dev_dbg(kp->dbg_dev, "key [%d:%d] %s\n", row, col,
228 				(new_state[row] & (1 << col)) ?
229 				"press" : "release");
230 
231 			code = MATRIX_SCAN_CODE(row, col, TWL4030_ROW_SHIFT);
232 			input_event(input, EV_MSC, MSC_SCAN, code);
233 			input_report_key(input, kp->keymap[code],
234 					 new_state[row] & (1 << col));
235 		}
236 		kp->kp_state[row] = new_state[row];
237 	}
238 	input_sync(input);
239 }
240 
241 /*
242  * Keypad interrupt handler
243  */
244 static irqreturn_t do_kp_irq(int irq, void *_kp)
245 {
246 	struct twl4030_keypad *kp = _kp;
247 	u8 reg;
248 	int ret;
249 
250 	/* Read & Clear TWL4030 pending interrupt */
251 	ret = twl4030_kpread(kp, &reg, KEYP_ISR1, 1);
252 
253 	/*
254 	 * Release all keys if I2C has gone bad or
255 	 * the KEYP has gone to idle state.
256 	 */
257 	if (ret >= 0 && (reg & KEYP_IMR1_KP))
258 		twl4030_kp_scan(kp, false);
259 	else
260 		twl4030_kp_scan(kp, true);
261 
262 	return IRQ_HANDLED;
263 }
264 
265 static int twl4030_kp_program(struct twl4030_keypad *kp)
266 {
267 	u8 reg;
268 	int i;
269 
270 	/* Enable controller, with hardware decoding but not autorepeat */
271 	reg = KEYP_CTRL_SOFT_NRST | KEYP_CTRL_SOFTMODEN
272 		| KEYP_CTRL_TOE_EN | KEYP_CTRL_KBD_ON;
273 	if (twl4030_kpwrite_u8(kp, reg, KEYP_CTRL) < 0)
274 		return -EIO;
275 
276 	/*
277 	 * NOTE: we could use sih_setup() here to package keypad
278 	 * event sources as four different IRQs ... but we don't.
279 	 */
280 
281 	/* Enable TO rising and KP rising and falling edge detection */
282 	reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING;
283 	if (twl4030_kpwrite_u8(kp, reg, KEYP_EDR) < 0)
284 		return -EIO;
285 
286 	/* Set PTV prescaler Field */
287 	reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT);
288 	if (twl4030_kpwrite_u8(kp, reg, KEYP_LK_PTV) < 0)
289 		return -EIO;
290 
291 	/* Set key debounce time to 20 ms */
292 	i = KEYP_PERIOD_US(20000, PTV_PRESCALER);
293 	if (twl4030_kpwrite_u8(kp, i, KEYP_DEB) < 0)
294 		return -EIO;
295 
296 	/* Set timeout period to 200 ms */
297 	i = KEYP_PERIOD_US(200000, PTV_PRESCALER);
298 	if (twl4030_kpwrite_u8(kp, (i & 0xFF), KEYP_TIMEOUT_L) < 0)
299 		return -EIO;
300 
301 	if (twl4030_kpwrite_u8(kp, (i >> 8), KEYP_TIMEOUT_H) < 0)
302 		return -EIO;
303 
304 	/*
305 	 * Enable Clear-on-Read; disable remembering events that fire
306 	 * after the IRQ but before our handler acks (reads) them.
307 	 */
308 	reg = TWL4030_SIH_CTRL_COR_MASK | TWL4030_SIH_CTRL_PENDDIS_MASK;
309 	if (twl4030_kpwrite_u8(kp, reg, KEYP_SIH_CTRL) < 0)
310 		return -EIO;
311 
312 	/* initialize key state; irqs update it from here on */
313 	if (twl4030_read_kp_matrix_state(kp, kp->kp_state) < 0)
314 		return -EIO;
315 
316 	return 0;
317 }
318 
319 /*
320  * Registers keypad device with input subsystem
321  * and configures TWL4030 keypad registers
322  */
323 static int twl4030_kp_probe(struct platform_device *pdev)
324 {
325 	struct twl4030_keypad_data *pdata = dev_get_platdata(&pdev->dev);
326 	const struct matrix_keymap_data *keymap_data = NULL;
327 	struct twl4030_keypad *kp;
328 	struct input_dev *input;
329 	u8 reg;
330 	int error;
331 
332 	kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL);
333 	if (!kp)
334 		return -ENOMEM;
335 
336 	input = devm_input_allocate_device(&pdev->dev);
337 	if (!input)
338 		return -ENOMEM;
339 
340 	/* get the debug device */
341 	kp->dbg_dev		= &pdev->dev;
342 	kp->input		= input;
343 
344 	/* setup input device */
345 	input->name		= "TWL4030 Keypad";
346 	input->phys		= "twl4030_keypad/input0";
347 
348 	input->id.bustype	= BUS_HOST;
349 	input->id.vendor	= 0x0001;
350 	input->id.product	= 0x0001;
351 	input->id.version	= 0x0003;
352 
353 	if (pdata) {
354 		if (!pdata->rows || !pdata->cols || !pdata->keymap_data) {
355 			dev_err(&pdev->dev, "Missing platform_data\n");
356 			return -EINVAL;
357 		}
358 
359 		kp->n_rows = pdata->rows;
360 		kp->n_cols = pdata->cols;
361 		kp->autorepeat = pdata->rep;
362 		keymap_data = pdata->keymap_data;
363 	} else {
364 		error = matrix_keypad_parse_properties(&pdev->dev, &kp->n_rows,
365 						       &kp->n_cols);
366 		if (error)
367 			return error;
368 
369 		kp->autorepeat = true;
370 	}
371 
372 	if (kp->n_rows > TWL4030_MAX_ROWS || kp->n_cols > TWL4030_MAX_COLS) {
373 		dev_err(&pdev->dev,
374 			"Invalid rows/cols amount specified in platform/devicetree data\n");
375 		return -EINVAL;
376 	}
377 
378 	kp->irq = platform_get_irq(pdev, 0);
379 	if (kp->irq < 0)
380 		return kp->irq;
381 
382 	error = matrix_keypad_build_keymap(keymap_data, NULL,
383 					   TWL4030_MAX_ROWS,
384 					   1 << TWL4030_ROW_SHIFT,
385 					   kp->keymap, input);
386 	if (error) {
387 		dev_err(kp->dbg_dev, "Failed to build keymap\n");
388 		return error;
389 	}
390 
391 	input_set_capability(input, EV_MSC, MSC_SCAN);
392 	/* Enable auto repeat feature of Linux input subsystem */
393 	if (kp->autorepeat)
394 		__set_bit(EV_REP, input->evbit);
395 
396 	error = input_register_device(input);
397 	if (error) {
398 		dev_err(kp->dbg_dev,
399 			"Unable to register twl4030 keypad device\n");
400 		return error;
401 	}
402 
403 	error = twl4030_kp_program(kp);
404 	if (error)
405 		return error;
406 
407 	/*
408 	 * This ISR will always execute in kernel thread context because of
409 	 * the need to access the TWL4030 over the I2C bus.
410 	 *
411 	 * NOTE:  we assume this host is wired to TWL4040 INT1, not INT2 ...
412 	 */
413 	error = devm_request_threaded_irq(&pdev->dev, kp->irq, NULL, do_kp_irq,
414 					  0, pdev->name, kp);
415 	if (error) {
416 		dev_info(kp->dbg_dev, "request_irq failed for irq no=%d: %d\n",
417 			kp->irq, error);
418 		return error;
419 	}
420 
421 	/* Enable KP and TO interrupts now. */
422 	reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO);
423 	if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) {
424 		/* mask all events - we don't care about the result */
425 		(void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1);
426 		return -EIO;
427 	}
428 
429 	return 0;
430 }
431 
432 #ifdef CONFIG_OF
433 static const struct of_device_id twl4030_keypad_dt_match_table[] = {
434 	{ .compatible = "ti,twl4030-keypad" },
435 	{},
436 };
437 MODULE_DEVICE_TABLE(of, twl4030_keypad_dt_match_table);
438 #endif
439 
440 /*
441  * NOTE: twl4030 are multi-function devices connected via I2C.
442  * So this device is a child of an I2C parent, thus it needs to
443  * support unplug/replug (which most platform devices don't).
444  */
445 
446 static struct platform_driver twl4030_kp_driver = {
447 	.probe		= twl4030_kp_probe,
448 	.driver		= {
449 		.name	= "twl4030_keypad",
450 		.of_match_table = of_match_ptr(twl4030_keypad_dt_match_table),
451 	},
452 };
453 module_platform_driver(twl4030_kp_driver);
454 
455 MODULE_AUTHOR("Texas Instruments");
456 MODULE_DESCRIPTION("TWL4030 Keypad Driver");
457 MODULE_LICENSE("GPL");
458 MODULE_ALIAS("platform:twl4030_keypad");
459