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(mod_no: TWL4030_MODULE_KEYPAD, value: 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(mod_no: TWL4030_MODULE_KEYPAD, val: 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, data: new_state, |
169 | KEYP_FULL_CODE_7_0, num_bytes: kp->n_rows); |
170 | if (ret >= 0) |
171 | for (row = 0; row < kp->n_rows; row++) |
172 | state[row] = twl4030_col_xlate(kp, col: 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, state: new_state); |
205 | |
206 | if (ret < 0) /* panic ... */ |
207 | return; |
208 | |
209 | if (twl4030_is_in_ghost_state(kp, key_state: 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(dev: input, EV_MSC, MSC_SCAN, value: code); |
233 | input_report_key(dev: input, code: kp->keymap[code], |
234 | value: new_state[row] & (1 << col)); |
235 | } |
236 | kp->kp_state[row] = new_state[row]; |
237 | } |
238 | input_sync(dev: 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, data: ®, KEYP_ISR1, num_bytes: 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, release_all: false); |
259 | else |
260 | twl4030_kp_scan(kp, release_all: 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, data: 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, data: 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, data: 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, data: 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, data: (i & 0xFF), KEYP_TIMEOUT_L) < 0) |
299 | return -EIO; |
300 | |
301 | if (twl4030_kpwrite_u8(kp, data: (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, data: 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, state: 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(dev: &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(dev: &pdev->dev, size: 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(dev: &pdev->dev, rows: &kp->n_rows, |
365 | cols: &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 | cols: 1 << TWL4030_ROW_SHIFT, |
385 | keymap: kp->keymap, input_dev: input); |
386 | if (error) { |
387 | dev_err(kp->dbg_dev, "Failed to build keymap\n" ); |
388 | return error; |
389 | } |
390 | |
391 | input_set_capability(dev: 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(dev: &pdev->dev, irq: kp->irq, NULL, thread_fn: do_kp_irq, |
414 | irqflags: 0, devname: pdev->name, dev_id: 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, data: reg, KEYP_IMR1)) { |
424 | /* mask all events - we don't care about the result */ |
425 | (void) twl4030_kpwrite_u8(kp, data: 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 | |