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