drivers/input/keyboard/davinci_keyscan.c

   1 /*
   2  * DaVinci Key Scan Driver for TI platforms
   3  *
   4  * Copyright (C) 2009 Texas Instruments, Inc
   5  *
   6  * Author: Miguel Aguilar <miguel.aguilar@ridgerun.com>
   7  *
   8  * Initial Code: Sandeep Paulraj <s-paulraj@ti.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  */
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/types.h>
  28 #include <linux/input.h>
  29 #include <linux/kernel.h>
  30 #include <linux/delay.h>
  31 #include <linux/platform_device.h>
  32 #include <linux/errno.h>
  33 #include <linux/slab.h>
  34
  35 #include <asm/irq.h>
  36
  37 #include <mach/hardware.h>
  38 #include <mach/irqs.h>
  39 #include <linux/platform_data/keyscan-davinci.h>
  40
  41 /* Key scan registers */
  42 #define DAVINCI_KEYSCAN_KEYCTRL         0x0000
  43 #define DAVINCI_KEYSCAN_INTENA          0x0004
  44 #define DAVINCI_KEYSCAN_INTFLAG         0x0008
  45 #define DAVINCI_KEYSCAN_INTCLR          0x000c
  46 #define DAVINCI_KEYSCAN_STRBWIDTH       0x0010
  47 #define DAVINCI_KEYSCAN_INTERVAL        0x0014
  48 #define DAVINCI_KEYSCAN_CONTTIME        0x0018
  49 #define DAVINCI_KEYSCAN_CURRENTST       0x001c
  50 #define DAVINCI_KEYSCAN_PREVSTATE       0x0020
  51 #define DAVINCI_KEYSCAN_EMUCTRL         0x0024
  52 #define DAVINCI_KEYSCAN_IODFTCTRL       0x002c
  53
  54 /* Key Control Register (KEYCTRL) */
  55 #define DAVINCI_KEYSCAN_KEYEN           0x00000001
  56 #define DAVINCI_KEYSCAN_PREVMODE        0x00000002
  57 #define DAVINCI_KEYSCAN_CHATOFF         0x00000004
  58 #define DAVINCI_KEYSCAN_AUTODET         0x00000008
  59 #define DAVINCI_KEYSCAN_SCANMODE        0x00000010
  60 #define DAVINCI_KEYSCAN_OUTTYPE         0x00000020
  61
  62 /* Masks for the interrupts */
  63 #define DAVINCI_KEYSCAN_INT_CONT        0x00000008
  64 #define DAVINCI_KEYSCAN_INT_OFF         0x00000004
  65 #define DAVINCI_KEYSCAN_INT_ON          0x00000002
  66 #define DAVINCI_KEYSCAN_INT_CHANGE      0x00000001
  67 #define DAVINCI_KEYSCAN_INT_ALL         0x0000000f
  68
  69 struct davinci_ks {
  70         struct input_dev                *input;
  71         struct davinci_ks_platform_data *pdata;
  72         int                             irq;
  73         void __iomem                    *base;
  74         resource_size_t                 pbase;
  75         size_t                          base_size;
  76         unsigned short                  keymap[];
  77 };
  78
  79 /* Initializing the kp Module */
  80 static int __init davinci_ks_initialize(struct davinci_ks *davinci_ks)
  81 {
  82         struct device *dev = &davinci_ks->input->dev;
  83         struct davinci_ks_platform_data *pdata = davinci_ks->pdata;
  84         u32 matrix_ctrl;
  85
  86         /* Enable all interrupts */
  87         __raw_writel(DAVINCI_KEYSCAN_INT_ALL,
  88                      davinci_ks->base + DAVINCI_KEYSCAN_INTENA);
  89
  90         /* Clear interrupts if any */
  91         __raw_writel(DAVINCI_KEYSCAN_INT_ALL,
  92                      davinci_ks->base + DAVINCI_KEYSCAN_INTCLR);
  93
  94         /* Setup the scan period = strobe + interval */
  95         __raw_writel(pdata->strobe,
  96                      davinci_ks->base + DAVINCI_KEYSCAN_STRBWIDTH);
  97         __raw_writel(pdata->interval,
  98                      davinci_ks->base + DAVINCI_KEYSCAN_INTERVAL);
  99         __raw_writel(0x01,
 100                      davinci_ks->base + DAVINCI_KEYSCAN_CONTTIME);
 101
 102         /* Define matrix type */
 103         switch (pdata->matrix_type) {
 104         case DAVINCI_KEYSCAN_MATRIX_4X4:
 105                 matrix_ctrl = 0;
 106                 break;
 107         case DAVINCI_KEYSCAN_MATRIX_5X3:
 108                 matrix_ctrl = (1 << 6);
 109                 break;
 110         default:
 111                 dev_err(dev->parent, "wrong matrix type\n");
 112                 return -EINVAL;
 113         }
 114
 115         /* Enable key scan module and set matrix type */
 116         __raw_writel(DAVINCI_KEYSCAN_AUTODET | DAVINCI_KEYSCAN_KEYEN |
 117                      matrix_ctrl, davinci_ks->base + DAVINCI_KEYSCAN_KEYCTRL);
 118
 119         return 0;
 120 }
 121
 122 static irqreturn_t davinci_ks_interrupt(int irq, void *dev_id)
 123 {
 124         struct davinci_ks *davinci_ks = dev_id;
 125         struct device *dev = &davinci_ks->input->dev;
 126         unsigned short *keymap = davinci_ks->keymap;
 127         int keymapsize = davinci_ks->pdata->keymapsize;
 128         u32 prev_status, new_status, changed;
 129         bool release;
 130         int keycode = KEY_UNKNOWN;
 131         int i;
 132
 133         /* Disable interrupt */
 134         __raw_writel(0x0, davinci_ks->base + DAVINCI_KEYSCAN_INTENA);
 135
 136         /* Reading previous and new status of the key scan */
 137         prev_status = __raw_readl(davinci_ks->base + DAVINCI_KEYSCAN_PREVSTATE);
 138         new_status = __raw_readl(davinci_ks->base + DAVINCI_KEYSCAN_CURRENTST);
 139
 140         changed = prev_status ^ new_status;
 141
 142         if (changed) {
 143                 /*
 144                  * It goes through all bits in 'changed' to ensure
 145                  * that no key changes are being missed
 146                  */
 147                 for (i = 0 ; i < keymapsize; i++) {
 148                         if ((changed>>i) & 0x1) {
 149                                 keycode = keymap[i];
 150                                 release = (new_status >> i) & 0x1;
 151                                 dev_dbg(dev->parent, "key %d %s\n", keycode,
 152                                         release ? "released" : "pressed");
 153                                 input_report_key(davinci_ks->input, keycode,
 154                                                  !release);
 155                                 input_sync(davinci_ks->input);
 156                         }
 157                 }
 158                 /* Clearing interrupt */
 159                 __raw_writel(DAVINCI_KEYSCAN_INT_ALL,
 160                              davinci_ks->base + DAVINCI_KEYSCAN_INTCLR);
 161         }
 162
 163         /* Enable interrupts */
 164         __raw_writel(0x1, davinci_ks->base + DAVINCI_KEYSCAN_INTENA);
 165
 166         return IRQ_HANDLED;
 167 }
 168
 169 static int __init davinci_ks_probe(struct platform_device *pdev)
 170 {
 171         struct davinci_ks *davinci_ks;
 172         struct input_dev *key_dev;
 173         struct resource *res, *mem;
 174         struct device *dev = &pdev->dev;
 175         struct davinci_ks_platform_data *pdata = pdev->dev.platform_data;
 176         int error, i;
 177
 178         if (pdata->device_enable) {
 179                 error = pdata->device_enable(dev);
 180                 if (error < 0) {
 181                         dev_dbg(dev, "device enable function failed\n");
 182                         return error;
 183                 }
 184         }
 185
 186         if (!pdata->keymap) {
 187                 dev_dbg(dev, "no keymap from pdata\n");
 188                 return -EINVAL;
 189         }
 190
 191         davinci_ks = kzalloc(sizeof(struct davinci_ks) +
 192                 sizeof(unsigned short) * pdata->keymapsize, GFP_KERNEL);
 193         if (!davinci_ks) {
 194                 dev_dbg(dev, "could not allocate memory for private data\n");
 195                 return -ENOMEM;
 196         }
 197
 198         memcpy(davinci_ks->keymap, pdata->keymap,
 199                 sizeof(unsigned short) * pdata->keymapsize);
 200
 201         key_dev = input_allocate_device();
 202         if (!key_dev) {
 203                 dev_dbg(dev, "could not allocate input device\n");
 204                 error = -ENOMEM;
 205                 goto fail1;
 206         }
 207
 208         davinci_ks->input = key_dev;
 209
 210         davinci_ks->irq = platform_get_irq(pdev, 0);
 211         if (davinci_ks->irq < 0) {
 212                 dev_err(dev, "no key scan irq\n");
 213                 error = davinci_ks->irq;
 214                 goto fail2;
 215         }
 216
 217         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 218         if (!res) {
 219                 dev_err(dev, "no mem resource\n");
 220                 error = -EINVAL;
 221                 goto fail2;
 222         }
 223
 224         davinci_ks->pbase = res->start;
 225         davinci_ks->base_size = resource_size(res);
 226
 227         mem = request_mem_region(davinci_ks->pbase, davinci_ks->base_size,
 228                                  pdev->name);
 229         if (!mem) {
 230                 dev_err(dev, "key scan registers at %08x are not free\n",
 231                         davinci_ks->pbase);
 232                 error = -EBUSY;
 233                 goto fail2;
 234         }
 235
 236         davinci_ks->base = ioremap(davinci_ks->pbase, davinci_ks->base_size);
 237         if (!davinci_ks->base) {
 238                 dev_err(dev, "can't ioremap MEM resource.\n");
 239                 error = -ENOMEM;
 240                 goto fail3;
 241         }
 242
 243         /* Enable auto repeat feature of Linux input subsystem */
 244         if (pdata->rep)
 245                 __set_bit(EV_REP, key_dev->evbit);
 246
 247         /* Setup input device */
 248         __set_bit(EV_KEY, key_dev->evbit);
 249
 250         /* Setup the platform data */
 251         davinci_ks->pdata = pdata;
 252
 253         for (i = 0; i < davinci_ks->pdata->keymapsize; i++)
 254                 __set_bit(davinci_ks->pdata->keymap[i], key_dev->keybit);
 255
 256         key_dev->name = "davinci_keyscan";
 257         key_dev->phys = "davinci_keyscan/input0";
 258         key_dev->dev.parent = &pdev->dev;
 259         key_dev->id.bustype = BUS_HOST;
 260         key_dev->id.vendor = 0x0001;
 261         key_dev->id.product = 0x0001;
 262         key_dev->id.version = 0x0001;
 263         key_dev->keycode = davinci_ks->keymap;
 264         key_dev->keycodesize = sizeof(davinci_ks->keymap[0]);
 265         key_dev->keycodemax = davinci_ks->pdata->keymapsize;
 266
 267         error = input_register_device(davinci_ks->input);
 268         if (error < 0) {
 269                 dev_err(dev, "unable to register davinci key scan device\n");
 270                 goto fail4;
 271         }
 272
 273         error = request_irq(davinci_ks->irq, davinci_ks_interrupt,
 274                           0, pdev->name, davinci_ks);
 275         if (error < 0) {
 276                 dev_err(dev, "unable to register davinci key scan interrupt\n");
 277                 goto fail5;
 278         }
 279
 280         error = davinci_ks_initialize(davinci_ks);
 281         if (error < 0) {
 282                 dev_err(dev, "unable to initialize davinci key scan device\n");
 283                 goto fail6;
 284         }
 285
 286         platform_set_drvdata(pdev, davinci_ks);
 287         return 0;
 288
 289 fail6:
 290         free_irq(davinci_ks->irq, davinci_ks);
 291 fail5:
 292         input_unregister_device(davinci_ks->input);
 293         key_dev = NULL;
 294 fail4:
 295         iounmap(davinci_ks->base);
 296 fail3:
 297         release_mem_region(davinci_ks->pbase, davinci_ks->base_size);
 298 fail2:
 299         input_free_device(key_dev);
 300 fail1:
 301         kfree(davinci_ks);
 302
 303         return error;
 304 }
 305
 306 static int davinci_ks_remove(struct platform_device *pdev)
 307 {
 308         struct davinci_ks *davinci_ks = platform_get_drvdata(pdev);
 309
 310         free_irq(davinci_ks->irq, davinci_ks);
 311
 312         input_unregister_device(davinci_ks->input);
 313
 314         iounmap(davinci_ks->base);
 315         release_mem_region(davinci_ks->pbase, davinci_ks->base_size);
 316
 317         kfree(davinci_ks);
 318
 319         return 0;
 320 }
 321
 322 static struct platform_driver davinci_ks_driver = {
 323         .driver = {
 324                 .name = "davinci_keyscan",
 325                 .owner = THIS_MODULE,
 326         },
 327         .remove = davinci_ks_remove,
 328 };
 329
 330 module_platform_driver_probe(davinci_ks_driver, davinci_ks_probe);
 331
 332 MODULE_AUTHOR("Miguel Aguilar");
 333 MODULE_DESCRIPTION("Texas Instruments DaVinci Key Scan Driver");
 334 MODULE_LICENSE("GPL");