drivers/input/keyboard/davinci_keyscan.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * DaVinci Key Scan Driver for TI platforms
   4  *
   5  * Copyright (C) 2009 Texas Instruments, Inc
   6  *
   7  * Author: Miguel Aguilar <miguel.aguilar@ridgerun.com>
   8  *
   9  * Initial Code: Sandeep Paulraj <s-paulraj@ti.com>
  10  */
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/types.h>
  15 #include <linux/input.h>
  16 #include <linux/kernel.h>
  17 #include <linux/delay.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/errno.h>
  20 #include <linux/slab.h>
  21
  22 #include <linux/platform_data/keyscan-davinci.h>
  23
  24 /* Key scan registers */
  25 #define DAVINCI_KEYSCAN_KEYCTRL         0x0000
  26 #define DAVINCI_KEYSCAN_INTENA          0x0004
  27 #define DAVINCI_KEYSCAN_INTFLAG         0x0008
  28 #define DAVINCI_KEYSCAN_INTCLR          0x000c
  29 #define DAVINCI_KEYSCAN_STRBWIDTH       0x0010
  30 #define DAVINCI_KEYSCAN_INTERVAL        0x0014
  31 #define DAVINCI_KEYSCAN_CONTTIME        0x0018
  32 #define DAVINCI_KEYSCAN_CURRENTST       0x001c
  33 #define DAVINCI_KEYSCAN_PREVSTATE       0x0020
  34 #define DAVINCI_KEYSCAN_EMUCTRL         0x0024
  35 #define DAVINCI_KEYSCAN_IODFTCTRL       0x002c
  36
  37 /* Key Control Register (KEYCTRL) */
  38 #define DAVINCI_KEYSCAN_KEYEN           0x00000001
  39 #define DAVINCI_KEYSCAN_PREVMODE        0x00000002
  40 #define DAVINCI_KEYSCAN_CHATOFF         0x00000004
  41 #define DAVINCI_KEYSCAN_AUTODET         0x00000008
  42 #define DAVINCI_KEYSCAN_SCANMODE        0x00000010
  43 #define DAVINCI_KEYSCAN_OUTTYPE         0x00000020
  44
  45 /* Masks for the interrupts */
  46 #define DAVINCI_KEYSCAN_INT_CONT        0x00000008
  47 #define DAVINCI_KEYSCAN_INT_OFF         0x00000004
  48 #define DAVINCI_KEYSCAN_INT_ON          0x00000002
  49 #define DAVINCI_KEYSCAN_INT_CHANGE      0x00000001
  50 #define DAVINCI_KEYSCAN_INT_ALL         0x0000000f
  51
  52 struct davinci_ks {
  53         struct input_dev                *input;
  54         struct davinci_ks_platform_data *pdata;
  55         int                             irq;
  56         void __iomem                    *base;
  57         resource_size_t                 pbase;
  58         size_t                          base_size;
  59         unsigned short                  keymap[];
  60 };
  61
  62 /* Initializing the kp Module */
  63 static int __init davinci_ks_initialize(struct davinci_ks *davinci_ks)
  64 {
  65         struct device *dev = &davinci_ks->input->dev;
  66         struct davinci_ks_platform_data *pdata = davinci_ks->pdata;
  67         u32 matrix_ctrl;
  68
  69         /* Enable all interrupts */
  70         __raw_writel(DAVINCI_KEYSCAN_INT_ALL,
  71                      davinci_ks->base + DAVINCI_KEYSCAN_INTENA);
  72
  73         /* Clear interrupts if any */
  74         __raw_writel(DAVINCI_KEYSCAN_INT_ALL,
  75                      davinci_ks->base + DAVINCI_KEYSCAN_INTCLR);
  76
  77         /* Setup the scan period = strobe + interval */
  78         __raw_writel(pdata->strobe,
  79                      davinci_ks->base + DAVINCI_KEYSCAN_STRBWIDTH);
  80         __raw_writel(pdata->interval,
  81                      davinci_ks->base + DAVINCI_KEYSCAN_INTERVAL);
  82         __raw_writel(0x01,
  83                      davinci_ks->base + DAVINCI_KEYSCAN_CONTTIME);
  84
  85         /* Define matrix type */
  86         switch (pdata->matrix_type) {
  87         case DAVINCI_KEYSCAN_MATRIX_4X4:
  88                 matrix_ctrl = 0;
  89                 break;
  90         case DAVINCI_KEYSCAN_MATRIX_5X3:
  91                 matrix_ctrl = (1 << 6);
  92                 break;
  93         default:
  94                 dev_err(dev->parent, "wrong matrix type\n");
  95                 return -EINVAL;
  96         }
  97
  98         /* Enable key scan module and set matrix type */
  99         __raw_writel(DAVINCI_KEYSCAN_AUTODET | DAVINCI_KEYSCAN_KEYEN |
 100                      matrix_ctrl, davinci_ks->base + DAVINCI_KEYSCAN_KEYCTRL);
 101
 102         return 0;
 103 }
 104
 105 static irqreturn_t davinci_ks_interrupt(int irq, void *dev_id)
 106 {
 107         struct davinci_ks *davinci_ks = dev_id;
 108         struct device *dev = &davinci_ks->input->dev;
 109         unsigned short *keymap = davinci_ks->keymap;
 110         int keymapsize = davinci_ks->pdata->keymapsize;
 111         u32 prev_status, new_status, changed;
 112         bool release;
 113         int keycode = KEY_UNKNOWN;
 114         int i;
 115
 116         /* Disable interrupt */
 117         __raw_writel(0x0, davinci_ks->base + DAVINCI_KEYSCAN_INTENA);
 118
 119         /* Reading previous and new status of the key scan */
 120         prev_status = __raw_readl(davinci_ks->base + DAVINCI_KEYSCAN_PREVSTATE);
 121         new_status = __raw_readl(davinci_ks->base + DAVINCI_KEYSCAN_CURRENTST);
 122
 123         changed = prev_status ^ new_status;
 124
 125         if (changed) {
 126                 /*
 127                  * It goes through all bits in 'changed' to ensure
 128                  * that no key changes are being missed
 129                  */
 130                 for (i = 0 ; i < keymapsize; i++) {
 131                         if ((changed>>i) & 0x1) {
 132                                 keycode = keymap[i];
 133                                 release = (new_status >> i) & 0x1;
 134                                 dev_dbg(dev->parent, "key %d %s\n", keycode,
 135                                         release ? "released" : "pressed");
 136                                 input_report_key(davinci_ks->input, keycode,
 137                                                  !release);
 138                                 input_sync(davinci_ks->input);
 139                         }
 140                 }
 141                 /* Clearing interrupt */
 142                 __raw_writel(DAVINCI_KEYSCAN_INT_ALL,
 143                              davinci_ks->base + DAVINCI_KEYSCAN_INTCLR);
 144         }
 145
 146         /* Enable interrupts */
 147         __raw_writel(0x1, davinci_ks->base + DAVINCI_KEYSCAN_INTENA);
 148
 149         return IRQ_HANDLED;
 150 }
 151
 152 static int __init davinci_ks_probe(struct platform_device *pdev)
 153 {
 154         struct davinci_ks *davinci_ks;
 155         struct input_dev *key_dev;
 156         struct resource *res, *mem;
 157         struct device *dev = &pdev->dev;
 158         struct davinci_ks_platform_data *pdata = dev_get_platdata(dev);
 159         int error, i;
 160
 161         if (pdata->device_enable) {
 162                 error = pdata->device_enable(dev);
 163                 if (error < 0) {
 164                         dev_dbg(dev, "device enable function failed\n");
 165                         return error;
 166                 }
 167         }
 168
 169         if (!pdata->keymap) {
 170                 dev_dbg(dev, "no keymap from pdata\n");
 171                 return -EINVAL;
 172         }
 173
 174         davinci_ks = kzalloc(sizeof(struct davinci_ks) +
 175                 sizeof(unsigned short) * pdata->keymapsize, GFP_KERNEL);
 176         if (!davinci_ks) {
 177                 dev_dbg(dev, "could not allocate memory for private data\n");
 178                 return -ENOMEM;
 179         }
 180
 181         memcpy(davinci_ks->keymap, pdata->keymap,
 182                 sizeof(unsigned short) * pdata->keymapsize);
 183
 184         key_dev = input_allocate_device();
 185         if (!key_dev) {
 186                 dev_dbg(dev, "could not allocate input device\n");
 187                 error = -ENOMEM;
 188                 goto fail1;
 189         }
 190
 191         davinci_ks->input = key_dev;
 192
 193         davinci_ks->irq = platform_get_irq(pdev, 0);
 194         if (davinci_ks->irq < 0) {
 195                 dev_err(dev, "no key scan irq\n");
 196                 error = davinci_ks->irq;
 197                 goto fail2;
 198         }
 199
 200         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 201         if (!res) {
 202                 dev_err(dev, "no mem resource\n");
 203                 error = -EINVAL;
 204                 goto fail2;
 205         }
 206
 207         davinci_ks->pbase = res->start;
 208         davinci_ks->base_size = resource_size(res);
 209
 210         mem = request_mem_region(davinci_ks->pbase, davinci_ks->base_size,
 211                                  pdev->name);
 212         if (!mem) {
 213                 dev_err(dev, "key scan registers at %08x are not free\n",
 214                         davinci_ks->pbase);
 215                 error = -EBUSY;
 216                 goto fail2;
 217         }
 218
 219         davinci_ks->base = ioremap(davinci_ks->pbase, davinci_ks->base_size);
 220         if (!davinci_ks->base) {
 221                 dev_err(dev, "can't ioremap MEM resource.\n");
 222                 error = -ENOMEM;
 223                 goto fail3;
 224         }
 225
 226         /* Enable auto repeat feature of Linux input subsystem */
 227         if (pdata->rep)
 228                 __set_bit(EV_REP, key_dev->evbit);
 229
 230         /* Setup input device */
 231         __set_bit(EV_KEY, key_dev->evbit);
 232
 233         /* Setup the platform data */
 234         davinci_ks->pdata = pdata;
 235
 236         for (i = 0; i < davinci_ks->pdata->keymapsize; i++)
 237                 __set_bit(davinci_ks->pdata->keymap[i], key_dev->keybit);
 238
 239         key_dev->name = "davinci_keyscan";
 240         key_dev->phys = "davinci_keyscan/input0";
 241         key_dev->dev.parent = dev;
 242         key_dev->id.bustype = BUS_HOST;
 243         key_dev->id.vendor = 0x0001;
 244         key_dev->id.product = 0x0001;
 245         key_dev->id.version = 0x0001;
 246         key_dev->keycode = davinci_ks->keymap;
 247         key_dev->keycodesize = sizeof(davinci_ks->keymap[0]);
 248         key_dev->keycodemax = davinci_ks->pdata->keymapsize;
 249
 250         error = input_register_device(davinci_ks->input);
 251         if (error < 0) {
 252                 dev_err(dev, "unable to register davinci key scan device\n");
 253                 goto fail4;
 254         }
 255
 256         error = request_irq(davinci_ks->irq, davinci_ks_interrupt,
 257                           0, pdev->name, davinci_ks);
 258         if (error < 0) {
 259                 dev_err(dev, "unable to register davinci key scan interrupt\n");
 260                 goto fail5;
 261         }
 262
 263         error = davinci_ks_initialize(davinci_ks);
 264         if (error < 0) {
 265                 dev_err(dev, "unable to initialize davinci key scan device\n");
 266                 goto fail6;
 267         }
 268
 269         platform_set_drvdata(pdev, davinci_ks);
 270         return 0;
 271
 272 fail6:
 273         free_irq(davinci_ks->irq, davinci_ks);
 274 fail5:
 275         input_unregister_device(davinci_ks->input);
 276         key_dev = NULL;
 277 fail4:
 278         iounmap(davinci_ks->base);
 279 fail3:
 280         release_mem_region(davinci_ks->pbase, davinci_ks->base_size);
 281 fail2:
 282         input_free_device(key_dev);
 283 fail1:
 284         kfree(davinci_ks);
 285
 286         return error;
 287 }
 288
 289 static int davinci_ks_remove(struct platform_device *pdev)
 290 {
 291         struct davinci_ks *davinci_ks = platform_get_drvdata(pdev);
 292
 293         free_irq(davinci_ks->irq, davinci_ks);
 294
 295         input_unregister_device(davinci_ks->input);
 296
 297         iounmap(davinci_ks->base);
 298         release_mem_region(davinci_ks->pbase, davinci_ks->base_size);
 299
 300         kfree(davinci_ks);
 301
 302         return 0;
 303 }
 304
 305 static struct platform_driver davinci_ks_driver = {
 306         .driver = {
 307                 .name = "davinci_keyscan",
 308         },
 309         .remove = davinci_ks_remove,
 310 };
 311
 312 module_platform_driver_probe(davinci_ks_driver, davinci_ks_probe);
 313
 314 MODULE_AUTHOR("Miguel Aguilar");
 315 MODULE_DESCRIPTION("Texas Instruments DaVinci Key Scan Driver");
 316 MODULE_LICENSE("GPL");