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 unsigned 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, ®, 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) { 380 dev_err(&pdev->dev, "no keyboard irq assigned\n"); 381 return -EINVAL; 382 } 383 384 error = matrix_keypad_build_keymap(keymap_data, NULL, 385 TWL4030_MAX_ROWS, 386 1 << TWL4030_ROW_SHIFT, 387 kp->keymap, input); 388 if (error) { 389 dev_err(kp->dbg_dev, "Failed to build keymap\n"); 390 return error; 391 } 392 393 input_set_capability(input, EV_MSC, MSC_SCAN); 394 /* Enable auto repeat feature of Linux input subsystem */ 395 if (kp->autorepeat) 396 __set_bit(EV_REP, input->evbit); 397 398 error = input_register_device(input); 399 if (error) { 400 dev_err(kp->dbg_dev, 401 "Unable to register twl4030 keypad device\n"); 402 return error; 403 } 404 405 error = twl4030_kp_program(kp); 406 if (error) 407 return error; 408 409 /* 410 * This ISR will always execute in kernel thread context because of 411 * the need to access the TWL4030 over the I2C bus. 412 * 413 * NOTE: we assume this host is wired to TWL4040 INT1, not INT2 ... 414 */ 415 error = devm_request_threaded_irq(&pdev->dev, kp->irq, NULL, do_kp_irq, 416 0, pdev->name, kp); 417 if (error) { 418 dev_info(kp->dbg_dev, "request_irq failed for irq no=%d: %d\n", 419 kp->irq, error); 420 return error; 421 } 422 423 /* Enable KP and TO interrupts now. */ 424 reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO); 425 if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) { 426 /* mask all events - we don't care about the result */ 427 (void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1); 428 return -EIO; 429 } 430 431 return 0; 432 } 433 434 #ifdef CONFIG_OF 435 static const struct of_device_id twl4030_keypad_dt_match_table[] = { 436 { .compatible = "ti,twl4030-keypad" }, 437 {}, 438 }; 439 MODULE_DEVICE_TABLE(of, twl4030_keypad_dt_match_table); 440 #endif 441 442 /* 443 * NOTE: twl4030 are multi-function devices connected via I2C. 444 * So this device is a child of an I2C parent, thus it needs to 445 * support unplug/replug (which most platform devices don't). 446 */ 447 448 static struct platform_driver twl4030_kp_driver = { 449 .probe = twl4030_kp_probe, 450 .driver = { 451 .name = "twl4030_keypad", 452 .of_match_table = of_match_ptr(twl4030_keypad_dt_match_table), 453 }, 454 }; 455 module_platform_driver(twl4030_kp_driver); 456 457 MODULE_AUTHOR("Texas Instruments"); 458 MODULE_DESCRIPTION("TWL4030 Keypad Driver"); 459 MODULE_LICENSE("GPL"); 460 MODULE_ALIAS("platform:twl4030_keypad"); 461