drivers/input/keyboard/omap-twl4030keypad.c

   1 /*
   2  * drivers/input/keyboard/omap-twl4030keypad.c
   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/module.h>
  29 #include <linux/init.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/types.h>
  32 #include <linux/input.h>
  33 #include <linux/kernel.h>
  34 #include <linux/delay.h>
  35 #include <linux/bitops.h>
  36 #include <linux/platform_device.h>
  37 #include <linux/i2c.h>
  38 #include <linux/i2c/twl4030.h>
  39 #include <linux/irq.h>
  40 #include <asm/arch/keypad.h>
  41 #include "twl4030-keypad.h"
  42
  43 #define PTV_PRESCALER           4
  44
  45 #define MAX_ROWS                8 /* TWL4030 hardlimit */
  46 #define ROWCOL_MASK             0xFF000000
  47 #define KEYNUM_MASK             0x00FFFFFF
  48
  49 /* Global variables */
  50 static int *keymap;
  51 static u16 kp_state[MAX_ROWS];
  52 static int n_rows, n_cols;
  53
  54 static struct device *dbg_dev;
  55 static struct input_dev *omap_twl4030kp;
  56
  57 static int twl4030_kpread(u32 module, u8 *data, u32 reg, u8 num_bytes)
  58 {
  59         int ret;
  60
  61         ret = twl4030_i2c_read(module, data, reg, num_bytes);
  62         if (ret < 0) {
  63                 dev_warn(dbg_dev, "Couldn't read TWL4030: %X - ret %d[%x]\n",
  64                          reg, ret, ret);
  65                 return ret;
  66         }
  67         return ret;
  68 }
  69
  70 static int twl4030_kpwrite_u8(u32 module, u8 data, u32 reg)
  71 {
  72         int ret;
  73
  74         ret = twl4030_i2c_write_u8(module, data, reg);
  75         if (ret < 0) {
  76                 dev_warn(dbg_dev, "Could not write TWL4030: %X - ret %d[%x]\n",
  77                          reg, ret, ret);
  78                 return ret;
  79         }
  80         return ret;
  81 }
  82
  83 static int omap_kp_find_key(int col, int row)
  84 {
  85         int i, rc;
  86
  87         rc = KEY(col, row, 0);
  88         for (i = 0; keymap[i] != 0; i++)
  89                 if ((keymap[i] & ROWCOL_MASK) == rc)
  90                         return keymap[i] & KEYNUM_MASK;
  91
  92         return -EINVAL;
  93 }
  94
  95 static inline u16 omap_kp_col_xlate(u8 col)
  96 {
  97         /* If all bits in a row are active for all coloumns then
  98          * we have that row line connected to gnd. Mark this
  99          * key on as if it was on matrix position n_cols (ie
 100          * one higher than the size of the matrix).
 101          */
 102         if (col == 0xFF)
 103                 return (1 << n_cols);
 104         else
 105                 return col & ((1 << n_cols) - 1);
 106 }
 107
 108 static int omap_kp_read_kp_matrix_state(u16 *state)
 109 {
 110         u8 new_state[MAX_ROWS];
 111         int row;
 112         int ret = twl4030_kpread(TWL4030_MODULE_KEYPAD,
 113                                  new_state, KEYP_FULL_CODE_7_0, n_rows);
 114         if (ret >= 0) {
 115                 for (row = 0; row < n_rows; row++)
 116                         state[row] = omap_kp_col_xlate(new_state[row]);
 117         }
 118         return ret;
 119 }
 120
 121 static int omap_kp_is_in_ghost_state(u16 *key_state)
 122 {
 123         int i;
 124         u16 check = 0;
 125
 126         for (i = 0; i < n_rows; i++) {
 127                 u16 col = key_state[i];
 128
 129                 if ((col & check) && hweight16(col) > 1)
 130                         return 1;
 131                 check |= col;
 132         }
 133
 134         return 0;
 135 }
 136
 137 static void twl4030_kp_scan(int release_all)
 138 {
 139         u16 new_state[MAX_ROWS];
 140         int col, row;
 141
 142         if (release_all)
 143                 memset(new_state, 0, sizeof(new_state));
 144         else {
 145                 /* check for any changes */
 146                 int ret = omap_kp_read_kp_matrix_state(new_state);
 147                 if (ret < 0)    /* panic ... */
 148                         return;
 149
 150                 if (omap_kp_is_in_ghost_state(new_state))
 151                         return;
 152         }
 153
 154         /* check for changes and print those */
 155         for (row = 0; row < n_rows; row++) {
 156                 int changed = new_state[row] ^ kp_state[row];
 157
 158                 if (!changed)
 159                         continue;
 160
 161                 for (col = 0; col < n_cols + 1; col++) {
 162                         int key;
 163
 164                         if (!(changed & (1 << col)))
 165                                 continue;
 166
 167                         dev_dbg(dbg_dev, "key [%d:%d] %s\n", row, col,
 168                                 (new_state[row] & (1 << col)) ?
 169                                 "press" : "release");
 170
 171                         key = omap_kp_find_key(col, row);
 172                         if (key < 0)
 173                                 dev_warn(dbg_dev, "Spurious key event %d-%d\n",
 174                                          col, row);
 175                         else
 176                                 input_report_key(omap_twl4030kp, key,
 177                                                  new_state[row] & (1 << col));
 178                 }
 179                 kp_state[row] = new_state[row];
 180         }
 181 }
 182
 183 /*
 184  * Keypad interrupt handler
 185  */
 186 static irqreturn_t do_kp_irq(int irq, void *dev_id)
 187 {
 188         u8 reg;
 189         int ret;
 190
 191         /* Read & Clear TWL4030 pending interrupt */
 192         ret = twl4030_kpread(TWL4030_MODULE_KEYPAD, &reg, KEYP_ISR1, 1);
 193
 194         /* Release all keys if I2C has gone bad or
 195          * the KEYP has gone to idle state */
 196         if ((ret >= 0) && (reg & KEYP_IMR1_KP))
 197                 twl4030_kp_scan(0);
 198         else
 199                 twl4030_kp_scan(1);
 200
 201         return IRQ_HANDLED;
 202 }
 203
 204 /*
 205  * Registers keypad device with input sub system
 206  * and configures TWL4030 keypad registers
 207  */
 208 static int __init omap_kp_probe(struct platform_device *pdev)
 209 {
 210         u8 reg;
 211         int i;
 212         int ret = 0;
 213         struct omap_kp_platform_data *pdata = pdev->dev.platform_data;
 214
 215         /* Get the debug Device */
 216         dbg_dev = &(pdev->dev);
 217
 218         if (!pdata->rows || !pdata->cols || !pdata->keymap) {
 219                 dev_err(dbg_dev, "No rows, cols or keymap from pdata\n");
 220                 return -EINVAL;
 221         }
 222
 223         omap_twl4030kp = input_allocate_device();
 224         if (omap_twl4030kp == NULL)
 225                 return -ENOMEM;
 226
 227         keymap = pdata->keymap;
 228         n_rows = pdata->rows;
 229         n_cols = pdata->cols;
 230
 231         /* setup input device */
 232         set_bit(EV_KEY, omap_twl4030kp->evbit);
 233
 234         /* Enable auto repeat feature of Linux input subsystem */
 235         if (pdata->rep)
 236                 set_bit(EV_REP, omap_twl4030kp->evbit);
 237
 238         for (i = 0; keymap[i] != 0; i++)
 239                 set_bit(keymap[i] & KEYNUM_MASK, omap_twl4030kp->keybit);
 240
 241         omap_twl4030kp->name            = "omap_twl4030keypad";
 242         omap_twl4030kp->phys            = "omap_twl4030keypad/input0";
 243         omap_twl4030kp->dev.parent      = &pdev->dev;
 244
 245         omap_twl4030kp->id.bustype      = BUS_HOST;
 246         omap_twl4030kp->id.vendor       = 0x0001;
 247         omap_twl4030kp->id.product      = 0x0001;
 248         omap_twl4030kp->id.version      = 0x0003;
 249
 250         omap_twl4030kp->keycode         = keymap;
 251         omap_twl4030kp->keycodesize     = sizeof(unsigned int);
 252         omap_twl4030kp->keycodemax      = pdata->keymapsize;
 253
 254         ret = input_register_device(omap_twl4030kp);
 255         if (ret < 0) {
 256                 dev_err(dbg_dev, "Unable to register twl4030 keypad device\n");
 257                 goto err2;
 258         }
 259
 260         /* Disable auto-repeat */
 261         reg = KEYP_CTRL_NOAUTORPT;
 262         ret = twl4030_kpwrite_u8(TWL4030_MODULE_KEYPAD, reg, KEYP_CTRL);
 263         if (ret < 0)
 264                 goto err3;
 265
 266         /* Enable TO rising and KP rising and falling edge detection */
 267         reg = KEYP_EDR_KP_BOTH | KEYP_EDR_TO_RISING;
 268         ret = twl4030_kpwrite_u8(TWL4030_MODULE_KEYPAD, reg, KEYP_EDR);
 269         if (ret < 0)
 270                 goto err3;
 271
 272         /* Set PTV prescaler Field */
 273         reg = (PTV_PRESCALER << KEYP_LK_PTV_PTV_SHIFT);
 274         ret = twl4030_kpwrite_u8(TWL4030_MODULE_KEYPAD, reg, KEYP_LK_PTV);
 275         if (ret < 0)
 276                 goto err3;
 277
 278         /* Set key debounce time to 20 ms */
 279         i = KEYP_PERIOD_US(20000, PTV_PRESCALER);
 280         ret = twl4030_kpwrite_u8(TWL4030_MODULE_KEYPAD, i, KEYP_DEB);
 281         if (ret < 0)
 282                 goto err3;
 283
 284         /* Set timeout period to 100 ms */
 285         i = KEYP_PERIOD_US(200000, PTV_PRESCALER);
 286         ret = twl4030_kpwrite_u8(TWL4030_MODULE_KEYPAD,
 287                                  (i & 0xFF), KEYP_TIMEOUT_L);
 288         if (ret < 0)
 289                 goto err3;
 290
 291         ret = twl4030_kpwrite_u8(TWL4030_MODULE_KEYPAD,
 292                                  (i >> 8), KEYP_TIMEOUT_H);
 293         if (ret < 0)
 294                 goto err3;
 295
 296         /* Enable Clear-on-Read */
 297         reg = KEYP_SIH_CTRL_COR | KEYP_SIH_CTRL_PEND_DIS;
 298         ret = twl4030_kpwrite_u8(TWL4030_MODULE_KEYPAD,
 299                                  reg, KEYP_SIH_CTRL);
 300         if (ret < 0)
 301                 goto err3;
 302
 303         /*
 304          * This ISR will always execute in kernel thread context because of
 305          * the need to access the TWL4030 over the I2C bus.
 306          */
 307         ret = request_irq(TWL4030_MODIRQ_KEYPAD, do_kp_irq,
 308                 IRQF_DISABLED, "TWL4030 Keypad", omap_twl4030kp);
 309         if (ret < 0) {
 310                 dev_info(dbg_dev, "request_irq failed for irq no=%d\n",
 311                         TWL4030_MODIRQ_KEYPAD);
 312                 goto err3;
 313         } else {
 314                 /* Enable KP and TO interrupts now. */
 315                 reg = ~(KEYP_IMR1_KP | KEYP_IMR1_TO);
 316                 ret = twl4030_kpwrite_u8(TWL4030_MODULE_KEYPAD,
 317                                          reg, KEYP_IMR1);
 318                 if (ret < 0)
 319                         goto err5;
 320         }
 321
 322         ret = omap_kp_read_kp_matrix_state(kp_state);
 323         if (ret < 0)
 324                 goto err4;
 325
 326         return ret;
 327 err5:
 328         /* mask all events - we don't care about the result */
 329         (void) twl4030_kpwrite_u8(TWL4030_MODULE_KEYPAD, 0xff, KEYP_IMR1);
 330 err4:
 331         free_irq(TWL4030_MODIRQ_KEYPAD, NULL);
 332 err3:
 333         input_unregister_device(omap_twl4030kp);
 334 err2:
 335         input_free_device(omap_twl4030kp);
 336         return -ENODEV;
 337 }
 338
 339 static int omap_kp_remove(struct platform_device *pdev)
 340 {
 341         free_irq(TWL4030_MODIRQ_KEYPAD, NULL);
 342
 343         input_unregister_device(omap_twl4030kp);
 344         return 0;
 345 }
 346
 347
 348 static struct platform_driver omap_kp_driver = {
 349         .probe          = omap_kp_probe,
 350         .remove         = omap_kp_remove,
 351         .driver         = {
 352                 .name   = "omap_twl4030keypad",
 353                 .owner  = THIS_MODULE,
 354         },
 355 };
 356
 357 /*
 358  * OMAP TWL4030 Keypad init
 359  */
 360 static int __devinit omap_kp_init(void)
 361 {
 362         return platform_driver_register(&omap_kp_driver);
 363 }
 364
 365 static void __exit omap_kp_exit(void)
 366 {
 367         platform_driver_unregister(&omap_kp_driver);
 368 }
 369
 370 module_init(omap_kp_init);
 371 module_exit(omap_kp_exit);
 372 MODULE_ALIAS("platform:omap_twl4030keypad");
 373 MODULE_AUTHOR("Texas Instruments");
 374 MODULE_DESCRIPTION("OMAP TWL4030 Keypad Driver");
 375 MODULE_LICENSE("GPL");
 376 MODULE_ALIAS("platform:omap_twl4030keypad");