twl4030_keypad.c revision 994c755a197df16aa8fd2a5f2de48500142494a0
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 37/* 38 * The TWL4030 family chips include a keypad controller that supports 39 * up to an 8x8 switch matrix. The controller can issue system wakeup 40 * events, since it uses only the always-on 32KiHz oscillator, and has 41 * an internal state machine that decodes pressed keys, including 42 * multi-key combinations. 43 * 44 * This driver lets boards define what keycodes they wish to report for 45 * which scancodes, as part of the "struct twl4030_keypad_data" used in 46 * the probe() routine. 47 * 48 * See the TPS65950 documentation; that's the general availability 49 * version of the TWL5030 second generation part. 50 */ 51#define TWL4030_MAX_ROWS 8 /* TWL4030 hard limit */ 52#define TWL4030_MAX_COLS 8 53/* 54 * Note that we add space for an extra column so that we can handle 55 * row lines connected to the gnd (see twl4030_col_xlate()). 56 */ 57#define TWL4030_ROW_SHIFT 4 58#define TWL4030_KEYMAP_SIZE (TWL4030_MAX_ROWS << TWL4030_ROW_SHIFT) 59 60struct twl4030_keypad { 61 unsigned short keymap[TWL4030_KEYMAP_SIZE]; 62 u16 kp_state[TWL4030_MAX_ROWS]; 63 unsigned n_rows; 64 unsigned n_cols; 65 unsigned irq; 66 67 struct device *dbg_dev; 68 struct input_dev *input; 69}; 70 71/*----------------------------------------------------------------------*/ 72 73/* arbitrary prescaler value 0..7 */ 74#define PTV_PRESCALER 4 75 76/* Register Offsets */ 77#define KEYP_CTRL 0x00 78#define KEYP_DEB 0x01 79#define KEYP_LONG_KEY 0x02 80#define KEYP_LK_PTV 0x03 81#define KEYP_TIMEOUT_L 0x04 82#define KEYP_TIMEOUT_H 0x05 83#define KEYP_KBC 0x06 84#define KEYP_KBR 0x07 85#define KEYP_SMS 0x08 86#define KEYP_FULL_CODE_7_0 0x09 /* row 0 column status */ 87#define KEYP_FULL_CODE_15_8 0x0a /* ... row 1 ... */ 88#define KEYP_FULL_CODE_23_16 0x0b 89#define KEYP_FULL_CODE_31_24 0x0c 90#define KEYP_FULL_CODE_39_32 0x0d 91#define KEYP_FULL_CODE_47_40 0x0e 92#define KEYP_FULL_CODE_55_48 0x0f 93#define KEYP_FULL_CODE_63_56 0x10 94#define KEYP_ISR1 0x11 95#define KEYP_IMR1 0x12 96#define KEYP_ISR2 0x13 97#define KEYP_IMR2 0x14 98#define KEYP_SIR 0x15 99#define KEYP_EDR 0x16 /* edge triggers */ 100#define KEYP_SIH_CTRL 0x17 101 102/* KEYP_CTRL_REG Fields */ 103#define KEYP_CTRL_SOFT_NRST BIT(0) 104#define KEYP_CTRL_SOFTMODEN BIT(1) 105#define KEYP_CTRL_LK_EN BIT(2) 106#define KEYP_CTRL_TOE_EN BIT(3) 107#define KEYP_CTRL_TOLE_EN BIT(4) 108#define KEYP_CTRL_RP_EN BIT(5) 109#define KEYP_CTRL_KBD_ON BIT(6) 110 111/* KEYP_DEB, KEYP_LONG_KEY, KEYP_TIMEOUT_x*/ 112#define KEYP_PERIOD_US(t, prescale) ((t) / (31 << (prescale + 1)) - 1) 113 114/* KEYP_LK_PTV_REG Fields */ 115#define KEYP_LK_PTV_PTV_SHIFT 5 116 117/* KEYP_{IMR,ISR,SIR} Fields */ 118#define KEYP_IMR1_MIS BIT(3) 119#define KEYP_IMR1_TO BIT(2) 120#define KEYP_IMR1_LK BIT(1) 121#define KEYP_IMR1_KP BIT(0) 122 123/* KEYP_EDR Fields */ 124#define KEYP_EDR_KP_FALLING 0x01 125#define KEYP_EDR_KP_RISING 0x02 126#define KEYP_EDR_KP_BOTH 0x03 127#define KEYP_EDR_LK_FALLING 0x04 128#define KEYP_EDR_LK_RISING 0x08 129#define KEYP_EDR_TO_FALLING 0x10 130#define KEYP_EDR_TO_RISING 0x20 131#define KEYP_EDR_MIS_FALLING 0x40 132#define KEYP_EDR_MIS_RISING 0x80 133 134 135/*----------------------------------------------------------------------*/ 136 137static int twl4030_kpread(struct twl4030_keypad *kp, 138 u8 *data, u32 reg, u8 num_bytes) 139{ 140 int ret = twl_i2c_read(TWL4030_MODULE_KEYPAD, data, reg, num_bytes); 141 142 if (ret < 0) 143 dev_warn(kp->dbg_dev, 144 "Couldn't read TWL4030: %X - ret %d[%x]\n", 145 reg, ret, ret); 146 147 return ret; 148} 149 150static int twl4030_kpwrite_u8(struct twl4030_keypad *kp, u8 data, u32 reg) 151{ 152 int ret = twl_i2c_write_u8(TWL4030_MODULE_KEYPAD, data, reg); 153 154 if (ret < 0) 155 dev_warn(kp->dbg_dev, 156 "Could not write TWL4030: %X - ret %d[%x]\n", 157 reg, ret, ret); 158 159 return ret; 160} 161 162static inline u16 twl4030_col_xlate(struct twl4030_keypad *kp, u8 col) 163{ 164 /* If all bits in a row are active for all coloumns then 165 * we have that row line connected to gnd. Mark this 166 * key on as if it was on matrix position n_cols (ie 167 * one higher than the size of the matrix). 168 */ 169 if (col == 0xFF) 170 return 1 << kp->n_cols; 171 else 172 return col & ((1 << kp->n_cols) - 1); 173} 174 175static int twl4030_read_kp_matrix_state(struct twl4030_keypad *kp, u16 *state) 176{ 177 u8 new_state[TWL4030_MAX_ROWS]; 178 int row; 179 int ret = twl4030_kpread(kp, new_state, 180 KEYP_FULL_CODE_7_0, kp->n_rows); 181 if (ret >= 0) 182 for (row = 0; row < kp->n_rows; row++) 183 state[row] = twl4030_col_xlate(kp, new_state[row]); 184 185 return ret; 186} 187 188static bool twl4030_is_in_ghost_state(struct twl4030_keypad *kp, u16 *key_state) 189{ 190 int i; 191 u16 check = 0; 192 193 for (i = 0; i < kp->n_rows; i++) { 194 u16 col = key_state[i]; 195 196 if ((col & check) && hweight16(col) > 1) 197 return true; 198 199 check |= col; 200 } 201 202 return false; 203} 204 205static void twl4030_kp_scan(struct twl4030_keypad *kp, bool release_all) 206{ 207 struct input_dev *input = kp->input; 208 u16 new_state[TWL4030_MAX_ROWS]; 209 int col, row; 210 211 if (release_all) 212 memset(new_state, 0, sizeof(new_state)); 213 else { 214 /* check for any changes */ 215 int ret = twl4030_read_kp_matrix_state(kp, new_state); 216 217 if (ret < 0) /* panic ... */ 218 return; 219 220 if (twl4030_is_in_ghost_state(kp, new_state)) 221 return; 222 } 223 224 /* check for changes and print those */ 225 for (row = 0; row < kp->n_rows; row++) { 226 int changed = new_state[row] ^ kp->kp_state[row]; 227 228 if (!changed) 229 continue; 230 231 /* Extra column handles "all gnd" rows */ 232 for (col = 0; col < kp->n_cols + 1; col++) { 233 int code; 234 235 if (!(changed & (1 << col))) 236 continue; 237 238 dev_dbg(kp->dbg_dev, "key [%d:%d] %s\n", row, col, 239 (new_state[row] & (1 << col)) ? 240 "press" : "release"); 241 242 code = MATRIX_SCAN_CODE(row, col, TWL4030_ROW_SHIFT); 243 input_event(input, EV_MSC, MSC_SCAN, code); 244 input_report_key(input, kp->keymap[code], 245 new_state[row] & (1 << col)); 246 } 247 kp->kp_state[row] = new_state[row]; 248 } 249 input_sync(input); 250} 251 252/* 253 * Keypad interrupt handler 254 */ 255static irqreturn_t do_kp_irq(int irq, void *_kp) 256{ 257 struct twl4030_keypad *kp = _kp; 258 u8 reg; 259 int ret; 260 261 /* Read & Clear TWL4030 pending interrupt */ 262 ret = twl4030_kpread(kp, ®, KEYP_ISR1, 1); 263 264 /* Release all keys if I2C has gone bad or 265 * the KEYP has gone to idle state */ 266 if (ret >= 0 && (reg & KEYP_IMR1_KP)) 267 twl4030_kp_scan(kp, false); 268 else 269 twl4030_kp_scan(kp, true); 270 271 return IRQ_HANDLED; 272} 273 274static int twl4030_kp_program(struct twl4030_keypad *kp) 275{ 276 u8 reg; 277 int i; 278 279 /* Enable controller, with hardware decoding but not autorepeat */ 280 reg = KEYP_CTRL_SOFT_NRST | KEYP_CTRL_SOFTMODEN 281 | KEYP_CTRL_TOE_EN | KEYP_CTRL_KBD_ON; 282 if (twl4030_kpwrite_u8(kp, reg, KEYP_CTRL) < 0) 283 return -EIO; 284 285 /* NOTE: we could use sih_setup() here to package keypad 286 * event sources as four different IRQs ... but we don't. 287 */ 288 289 /* Enable TO rising and KP rising and falling edge detection */ 290 reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING; 291 if (twl4030_kpwrite_u8(kp, reg, KEYP_EDR) < 0) 292 return -EIO; 293 294 /* Set PTV prescaler Field */ 295 reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT); 296 if (twl4030_kpwrite_u8(kp, reg, KEYP_LK_PTV) < 0) 297 return -EIO; 298 299 /* Set key debounce time to 20 ms */ 300 i = KEYP_PERIOD_US(20000, PTV_PRESCALER); 301 if (twl4030_kpwrite_u8(kp, i, KEYP_DEB) < 0) 302 return -EIO; 303 304 /* Set timeout period to 200 ms */ 305 i = KEYP_PERIOD_US(200000, PTV_PRESCALER); 306 if (twl4030_kpwrite_u8(kp, (i & 0xFF), KEYP_TIMEOUT_L) < 0) 307 return -EIO; 308 309 if (twl4030_kpwrite_u8(kp, (i >> 8), KEYP_TIMEOUT_H) < 0) 310 return -EIO; 311 312 /* 313 * Enable Clear-on-Read; disable remembering events that fire 314 * after the IRQ but before our handler acks (reads) them, 315 */ 316 reg = TWL4030_SIH_CTRL_COR_MASK | TWL4030_SIH_CTRL_PENDDIS_MASK; 317 if (twl4030_kpwrite_u8(kp, reg, KEYP_SIH_CTRL) < 0) 318 return -EIO; 319 320 /* initialize key state; irqs update it from here on */ 321 if (twl4030_read_kp_matrix_state(kp, kp->kp_state) < 0) 322 return -EIO; 323 324 return 0; 325} 326 327/* 328 * Registers keypad device with input subsystem 329 * and configures TWL4030 keypad registers 330 */ 331static int twl4030_kp_probe(struct platform_device *pdev) 332{ 333 struct twl4030_keypad_data *pdata = pdev->dev.platform_data; 334 const struct matrix_keymap_data *keymap_data; 335 struct twl4030_keypad *kp; 336 struct input_dev *input; 337 u8 reg; 338 int error; 339 340 if (!pdata || !pdata->rows || !pdata->cols || !pdata->keymap_data || 341 pdata->rows > TWL4030_MAX_ROWS || pdata->cols > TWL4030_MAX_COLS) { 342 dev_err(&pdev->dev, "Invalid platform_data\n"); 343 return -EINVAL; 344 } 345 346 keymap_data = pdata->keymap_data; 347 348 kp = kzalloc(sizeof(*kp), GFP_KERNEL); 349 input = input_allocate_device(); 350 if (!kp || !input) { 351 error = -ENOMEM; 352 goto err1; 353 } 354 355 /* Get the debug Device */ 356 kp->dbg_dev = &pdev->dev; 357 kp->input = input; 358 359 kp->n_rows = pdata->rows; 360 kp->n_cols = pdata->cols; 361 kp->irq = platform_get_irq(pdev, 0); 362 363 /* setup input device */ 364 input->name = "TWL4030 Keypad"; 365 input->phys = "twl4030_keypad/input0"; 366 input->dev.parent = &pdev->dev; 367 368 input->id.bustype = BUS_HOST; 369 input->id.vendor = 0x0001; 370 input->id.product = 0x0001; 371 input->id.version = 0x0003; 372 373 error = matrix_keypad_build_keymap(keymap_data, NULL, 374 TWL4030_MAX_ROWS, 375 1 << TWL4030_ROW_SHIFT, 376 kp->keymap, input); 377 if (error) { 378 dev_err(kp->dbg_dev, "Failed to build keymap\n"); 379 goto err1; 380 } 381 382 input_set_capability(input, EV_MSC, MSC_SCAN); 383 /* Enable auto repeat feature of Linux input subsystem */ 384 if (pdata->rep) 385 __set_bit(EV_REP, input->evbit); 386 387 error = input_register_device(input); 388 if (error) { 389 dev_err(kp->dbg_dev, 390 "Unable to register twl4030 keypad device\n"); 391 goto err1; 392 } 393 394 error = twl4030_kp_program(kp); 395 if (error) 396 goto err2; 397 398 /* 399 * This ISR will always execute in kernel thread context because of 400 * the need to access the TWL4030 over the I2C bus. 401 * 402 * NOTE: we assume this host is wired to TWL4040 INT1, not INT2 ... 403 */ 404 error = request_threaded_irq(kp->irq, NULL, do_kp_irq, 405 0, pdev->name, kp); 406 if (error) { 407 dev_info(kp->dbg_dev, "request_irq failed for irq no=%d\n", 408 kp->irq); 409 goto err2; 410 } 411 412 /* Enable KP and TO interrupts now. */ 413 reg = (u8) ~(KEYP_IMR1_KP | KEYP_IMR1_TO); 414 if (twl4030_kpwrite_u8(kp, reg, KEYP_IMR1)) { 415 error = -EIO; 416 goto err3; 417 } 418 419 platform_set_drvdata(pdev, kp); 420 return 0; 421 422err3: 423 /* mask all events - we don't care about the result */ 424 (void) twl4030_kpwrite_u8(kp, 0xff, KEYP_IMR1); 425 free_irq(kp->irq, kp); 426err2: 427 input_unregister_device(input); 428 input = NULL; 429err1: 430 input_free_device(input); 431 kfree(kp); 432 return error; 433} 434 435static int twl4030_kp_remove(struct platform_device *pdev) 436{ 437 struct twl4030_keypad *kp = platform_get_drvdata(pdev); 438 439 free_irq(kp->irq, kp); 440 input_unregister_device(kp->input); 441 kfree(kp); 442 443 return 0; 444} 445 446/* 447 * NOTE: twl4030 are multi-function devices connected via I2C. 448 * So this device is a child of an I2C parent, thus it needs to 449 * support unplug/replug (which most platform devices don't). 450 */ 451 452static struct platform_driver twl4030_kp_driver = { 453 .probe = twl4030_kp_probe, 454 .remove = twl4030_kp_remove, 455 .driver = { 456 .name = "twl4030_keypad", 457 .owner = THIS_MODULE, 458 }, 459}; 460module_platform_driver(twl4030_kp_driver); 461 462MODULE_AUTHOR("Texas Instruments"); 463MODULE_DESCRIPTION("TWL4030 Keypad Driver"); 464MODULE_LICENSE("GPL"); 465MODULE_ALIAS("platform:twl4030_keypad"); 466