twl4030_keypad.c revision 049f1cb2c115855858ae0b15d559d40296f43d37
1/* 2 * twl4030_keypad.c - driver for 8x8 keypad controller in twl4030 chips 3 * 4 * Copyright (C) 2007 Texas Instruments, Inc. 5 * Copyright (C) 2008 Nokia Corporation 6 * 7 * Code re-written for 2430SDP by: 8 * Syed Mohammed Khasim <x0khasim@ti.com> 9 * 10 * Initial Code: 11 * Manjunatha G K <manjugk@ti.com> 12 * 13 * This program is free software; you can redistribute it and/or modify 14 * it under the terms of the GNU General Public License as published by 15 * the Free Software Foundation; either version 2 of the License, or 16 * (at your option) any later version. 17 * 18 * This program is distributed in the hope that it will be useful, 19 * but WITHOUT ANY WARRANTY; without even the implied warranty of 20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 21 * GNU General Public License for more details. 22 * 23 * You should have received a copy of the GNU General Public License 24 * along with this program; if not, write to the Free Software 25 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 26 */ 27 28#include <linux/kernel.h> 29#include <linux/module.h> 30#include <linux/init.h> 31#include <linux/interrupt.h> 32#include <linux/input.h> 33#include <linux/platform_device.h> 34#include <linux/i2c/twl.h> 35#include <linux/slab.h> 36#include <linux/of.h> 37 38/* 39 * The TWL4030 family chips include a keypad controller that supports 40 * up to an 8x8 switch matrix. The controller can issue system wakeup 41 * events, since it uses only the always-on 32KiHz oscillator, and has 42 * an internal state machine that decodes pressed keys, including 43 * multi-key combinations. 44 * 45 * This driver lets boards define what keycodes they wish to report for 46 * which scancodes, as part of the "struct twl4030_keypad_data" used in 47 * the probe() routine. 48 * 49 * See the TPS65950 documentation; that's the general availability 50 * version of the TWL5030 second generation part. 51 */ 52#define TWL4030_MAX_ROWS 8 /* TWL4030 hard limit */ 53#define TWL4030_MAX_COLS 8 54/* 55 * Note that we add space for an extra column so that we can handle 56 * row lines connected to the gnd (see twl4030_col_xlate()). 57 */ 58#define TWL4030_ROW_SHIFT 4 59#define TWL4030_KEYMAP_SIZE (TWL4030_MAX_ROWS << TWL4030_ROW_SHIFT) 60 61struct twl4030_keypad { 62 unsigned short keymap[TWL4030_KEYMAP_SIZE]; 63 u16 kp_state[TWL4030_MAX_ROWS]; 64 bool autorepeat; 65 unsigned n_rows; 66 unsigned n_cols; 67 unsigned irq; 68 69 struct device *dbg_dev; 70 struct input_dev *input; 71}; 72 73/*----------------------------------------------------------------------*/ 74 75/* arbitrary prescaler value 0..7 */ 76#define PTV_PRESCALER 4 77 78/* Register Offsets */ 79#define KEYP_CTRL 0x00 80#define KEYP_DEB 0x01 81#define KEYP_LONG_KEY 0x02 82#define KEYP_LK_PTV 0x03 83#define KEYP_TIMEOUT_L 0x04 84#define KEYP_TIMEOUT_H 0x05 85#define KEYP_KBC 0x06 86#define KEYP_KBR 0x07 87#define KEYP_SMS 0x08 88#define KEYP_FULL_CODE_7_0 0x09 /* row 0 column status */ 89#define KEYP_FULL_CODE_15_8 0x0a /* ... row 1 ... */ 90#define KEYP_FULL_CODE_23_16 0x0b 91#define KEYP_FULL_CODE_31_24 0x0c 92#define KEYP_FULL_CODE_39_32 0x0d 93#define KEYP_FULL_CODE_47_40 0x0e 94#define KEYP_FULL_CODE_55_48 0x0f 95#define KEYP_FULL_CODE_63_56 0x10 96#define KEYP_ISR1 0x11 97#define KEYP_IMR1 0x12 98#define KEYP_ISR2 0x13 99#define KEYP_IMR2 0x14 100#define KEYP_SIR 0x15 101#define KEYP_EDR 0x16 /* edge triggers */ 102#define KEYP_SIH_CTRL 0x17 103 104/* KEYP_CTRL_REG Fields */ 105#define KEYP_CTRL_SOFT_NRST BIT(0) 106#define KEYP_CTRL_SOFTMODEN BIT(1) 107#define KEYP_CTRL_LK_EN BIT(2) 108#define KEYP_CTRL_TOE_EN BIT(3) 109#define KEYP_CTRL_TOLE_EN BIT(4) 110#define KEYP_CTRL_RP_EN BIT(5) 111#define KEYP_CTRL_KBD_ON BIT(6) 112 113/* KEYP_DEB, KEYP_LONG_KEY, KEYP_TIMEOUT_x*/ 114#define KEYP_PERIOD_US(t, prescale) ((t) / (31 << (prescale + 1)) - 1) 115 116/* KEYP_LK_PTV_REG Fields */ 117#define KEYP_LK_PTV_PTV_SHIFT 5 118 119/* KEYP_{IMR,ISR,SIR} Fields */ 120#define KEYP_IMR1_MIS BIT(3) 121#define KEYP_IMR1_TO BIT(2) 122#define KEYP_IMR1_LK BIT(1) 123#define KEYP_IMR1_KP BIT(0) 124 125/* KEYP_EDR Fields */ 126#define KEYP_EDR_KP_FALLING 0x01 127#define KEYP_EDR_KP_RISING 0x02 128#define KEYP_EDR_KP_BOTH 0x03 129#define KEYP_EDR_LK_FALLING 0x04 130#define KEYP_EDR_LK_RISING 0x08 131#define KEYP_EDR_TO_FALLING 0x10 132#define KEYP_EDR_TO_RISING 0x20 133#define KEYP_EDR_MIS_FALLING 0x40 134#define KEYP_EDR_MIS_RISING 0x80 135 136 137/*----------------------------------------------------------------------*/ 138 139static int twl4030_kpread(struct twl4030_keypad *kp, 140 u8 *data, u32 reg, u8 num_bytes) 141{ 142 int ret = twl_i2c_read(TWL4030_MODULE_KEYPAD, data, reg, num_bytes); 143 144 if (ret < 0) 145 dev_warn(kp->dbg_dev, 146 "Couldn't read TWL4030: %X - ret %d[%x]\n", 147 reg, ret, ret); 148 149 return ret; 150} 151 152static int twl4030_kpwrite_u8(struct twl4030_keypad *kp, u8 data, u32 reg) 153{ 154 int ret = twl_i2c_write_u8(TWL4030_MODULE_KEYPAD, data, reg); 155 156 if (ret < 0) 157 dev_warn(kp->dbg_dev, 158 "Could not write TWL4030: %X - ret %d[%x]\n", 159 reg, ret, ret); 160 161 return ret; 162} 163 164static inline u16 twl4030_col_xlate(struct twl4030_keypad *kp, u8 col) 165{ 166 /* If all bits in a row are active for all coloumns then 167 * we have that row line connected to gnd. Mark this 168 * key on as if it was on matrix position n_cols (ie 169 * one higher than the size of the matrix). 170 */ 171 if (col == 0xFF) 172 return 1 << kp->n_cols; 173 else 174 return col & ((1 << kp->n_cols) - 1); 175} 176 177static int twl4030_read_kp_matrix_state(struct twl4030_keypad *kp, u16 *state) 178{ 179 u8 new_state[TWL4030_MAX_ROWS]; 180 int row; 181 int ret = twl4030_kpread(kp, new_state, 182 KEYP_FULL_CODE_7_0, kp->n_rows); 183 if (ret >= 0) 184 for (row = 0; row < kp->n_rows; row++) 185 state[row] = twl4030_col_xlate(kp, new_state[row]); 186 187 return ret; 188} 189 190static bool twl4030_is_in_ghost_state(struct twl4030_keypad *kp, u16 *key_state) 191{ 192 int i; 193 u16 check = 0; 194 195 for (i = 0; i < kp->n_rows; i++) { 196 u16 col = key_state[i]; 197 198 if ((col & check) && hweight16(col) > 1) 199 return true; 200 201 check |= col; 202 } 203 204 return false; 205} 206 207static void twl4030_kp_scan(struct twl4030_keypad *kp, bool release_all) 208{ 209 struct input_dev *input = kp->input; 210 u16 new_state[TWL4030_MAX_ROWS]; 211 int col, row; 212 213 if (release_all) 214 memset(new_state, 0, sizeof(new_state)); 215 else { 216 /* check for any changes */ 217 int ret = twl4030_read_kp_matrix_state(kp, new_state); 218 219 if (ret < 0) /* panic ... */ 220 return; 221 222 if (twl4030_is_in_ghost_state(kp, new_state)) 223 return; 224 } 225 226 /* check for changes and print those */ 227 for (row = 0; row < kp->n_rows; row++) { 228 int changed = new_state[row] ^ kp->kp_state[row]; 229 230 if (!changed) 231 continue; 232 233 /* Extra column handles "all gnd" rows */ 234 for (col = 0; col < kp->n_cols + 1; col++) { 235 int code; 236 237 if (!(changed & (1 << col))) 238 continue; 239 240 dev_dbg(kp->dbg_dev, "key [%d:%d] %s\n", row, col, 241 (new_state[row] & (1 << col)) ? 242 "press" : "release"); 243 244 code = MATRIX_SCAN_CODE(row, col, TWL4030_ROW_SHIFT); 245 input_event(input, EV_MSC, MSC_SCAN, code); 246 input_report_key(input, kp->keymap[code], 247 new_state[row] & (1 << col)); 248 } 249 kp->kp_state[row] = new_state[row]; 250 } 251 input_sync(input); 252} 253 254/* 255 * Keypad interrupt handler 256 */ 257static irqreturn_t do_kp_irq(int irq, void *_kp) 258{ 259 struct twl4030_keypad *kp = _kp; 260 u8 reg; 261 int ret; 262 263 /* Read & Clear TWL4030 pending interrupt */ 264 ret = twl4030_kpread(kp, ®, KEYP_ISR1, 1); 265 266 /* Release all keys if I2C has gone bad or 267 * the KEYP has gone to idle state */ 268 if (ret >= 0 && (reg & KEYP_IMR1_KP)) 269 twl4030_kp_scan(kp, false); 270 else 271 twl4030_kp_scan(kp, true); 272 273 return IRQ_HANDLED; 274} 275 276static int twl4030_kp_program(struct twl4030_keypad *kp) 277{ 278 u8 reg; 279 int i; 280 281 /* Enable controller, with hardware decoding but not autorepeat */ 282 reg = KEYP_CTRL_SOFT_NRST | KEYP_CTRL_SOFTMODEN 283 | KEYP_CTRL_TOE_EN | KEYP_CTRL_KBD_ON; 284 if (twl4030_kpwrite_u8(kp, reg, KEYP_CTRL) < 0) 285 return -EIO; 286 287 /* NOTE: we could use sih_setup() here to package keypad 288 * event sources as four different IRQs ... but we don't. 289 */ 290 291 /* Enable TO rising and KP rising and falling edge detection */ 292 reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING; 293 if (twl4030_kpwrite_u8(kp, reg, KEYP_EDR) < 0) 294 return -EIO; 295 296 /* Set PTV prescaler Field */ 297 reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT); 298 if (twl4030_kpwrite_u8(kp, reg, KEYP_LK_PTV) < 0) 299 return -EIO; 300 301 /* Set key debounce time to 20 ms */ 302 i = KEYP_PERIOD_US(20000, PTV_PRESCALER); 303 if (twl4030_kpwrite_u8(kp, i, KEYP_DEB) < 0) 304 return -EIO; 305 306 /* Set timeout period to 200 ms */ 307 i = KEYP_PERIOD_US(200000, PTV_PRESCALER); 308 if (twl4030_kpwrite_u8(kp, (i & 0xFF), KEYP_TIMEOUT_L) < 0) 309 return -EIO; 310 311 if (twl4030_kpwrite_u8(kp, (i >> 8), KEYP_TIMEOUT_H) < 0) 312 return -EIO; 313 314 /* 315 * Enable Clear-on-Read; disable remembering events that fire 316 * after the IRQ but before our handler acks (reads) them, 317 */ 318 reg = TWL4030_SIH_CTRL_COR_MASK | TWL4030_SIH_CTRL_PENDDIS_MASK; 319 if (twl4030_kpwrite_u8(kp, reg, KEYP_SIH_CTRL) < 0) 320 return -EIO; 321 322 /* initialize key state; irqs update it from here on */ 323 if (twl4030_read_kp_matrix_state(kp, kp->kp_state) < 0) 324 return -EIO; 325 326 return 0; 327} 328 329/* 330 * Registers keypad device with input subsystem 331 * and configures TWL4030 keypad registers 332 */ 333static int twl4030_kp_probe(struct platform_device *pdev) 334{ 335 struct twl4030_keypad_data *pdata = dev_get_platdata(&pdev->dev); 336 const struct matrix_keymap_data *keymap_data = NULL; 337 struct twl4030_keypad *kp; 338 struct input_dev *input; 339 u8 reg; 340 int error; 341 342 kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL); 343 if (!kp) 344 return -ENOMEM; 345 346 input = devm_input_allocate_device(&pdev->dev); 347 if (!input) 348 return -ENOMEM; 349 350 /* get the debug device */ 351 kp->dbg_dev = &pdev->dev; 352 kp->input = input; 353 354 /* setup input device */ 355 input->name = "TWL4030 Keypad"; 356 input->phys = "twl4030_keypad/input0"; 357 358 input->id.bustype = BUS_HOST; 359 input->id.vendor = 0x0001; 360 input->id.product = 0x0001; 361 input->id.version = 0x0003; 362 363 if (pdata) { 364 if (!pdata->rows || !pdata->cols || !pdata->keymap_data) { 365 dev_err(&pdev->dev, "Missing platform_data\n"); 366 return -EINVAL; 367 } 368 369 kp->n_rows = pdata->rows; 370 kp->n_cols = pdata->cols; 371 kp->autorepeat = pdata->rep; 372 keymap_data = pdata->keymap_data; 373 } else { 374 error = matrix_keypad_parse_of_params(&pdev->dev, &kp->n_rows, 375 &kp->n_cols); 376 if (error) 377 return error; 378 379 kp->autorepeat = true; 380 } 381 382 if (kp->n_rows > TWL4030_MAX_ROWS || kp->n_cols > TWL4030_MAX_COLS) { 383 dev_err(&pdev->dev, 384 "Invalid rows/cols amount specified in platform/devicetree data\n"); 385 return -EINVAL; 386 } 387 388 kp->irq = platform_get_irq(pdev, 0); 389 if (!kp->irq) { 390 dev_err(&pdev->dev, "no keyboard irq assigned\n"); 391 return -EINVAL; 392 } 393 394 error = matrix_keypad_build_keymap(keymap_data, NULL, 395 TWL4030_MAX_ROWS, 396 1 << TWL4030_ROW_SHIFT, 397 kp->keymap, input); 398 if (error) { 399 dev_err(kp->dbg_dev, "Failed to build keymap\n"); 400 return error; 401 } 402 403 input_set_capability(input, EV_MSC, MSC_SCAN); 404 /* Enable auto repeat feature of Linux input subsystem */ 405 if (kp->autorepeat) 406 __set_bit(EV_REP, input->evbit); 407 408 error = input_register_device(input); 409 if (error) { 410 dev_err(kp->dbg_dev, 411 "Unable to register twl4030 keypad device\n"); 412 return error; 413 } 414 415 error = twl4030_kp_program(kp); 416 if (error) 417 return error; 418 419 /* 420 * This ISR will always execute in kernel thread context because of 421 * the need to access the TWL4030 over the I2C bus. 422 * 423 * NOTE: we assume this host is wired to TWL4040 INT1, not INT2 ... 424 */ 425 error = devm_request_threaded_irq(&pdev->dev, kp->irq, NULL, do_kp_irq, 426 0, pdev->name, kp); 427 if (error) { 428 dev_info(kp->dbg_dev, "request_irq failed for irq no=%d: %d\n", 429 kp->irq, error); 430 return error; 431 } 432 433 /* Enable KP and TO interrupts now. */ 434 reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO); 435 if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) { 436 /* mask all events - we don't care about the result */ 437 (void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1); 438 return -EIO; 439 } 440 441 platform_set_drvdata(pdev, kp); 442 return 0; 443} 444 445#ifdef CONFIG_OF 446static const struct of_device_id twl4030_keypad_dt_match_table[] = { 447 { .compatible = "ti,twl4030-keypad" }, 448 {}, 449}; 450MODULE_DEVICE_TABLE(of, twl4030_keypad_dt_match_table); 451#endif 452 453/* 454 * NOTE: twl4030 are multi-function devices connected via I2C. 455 * So this device is a child of an I2C parent, thus it needs to 456 * support unplug/replug (which most platform devices don't). 457 */ 458 459static struct platform_driver twl4030_kp_driver = { 460 .probe = twl4030_kp_probe, 461 .driver = { 462 .name = "twl4030_keypad", 463 .owner = THIS_MODULE, 464 .of_match_table = of_match_ptr(twl4030_keypad_dt_match_table), 465 }, 466}; 467module_platform_driver(twl4030_kp_driver); 468 469MODULE_AUTHOR("Texas Instruments"); 470MODULE_DESCRIPTION("TWL4030 Keypad Driver"); 471MODULE_LICENSE("GPL"); 472MODULE_ALIAS("platform:twl4030_keypad"); 473