drivers/input/keyboard/lpc32xx-keys.c

   1 /*
   2  * NXP LPC32xx SoC Key Scan Interface
   3  *
   4  * Authors:
   5  *    Kevin Wells <kevin.wells@nxp.com>
   6  *    Roland Stigge <stigge@antcom.de>
   7  *
   8  * Copyright (C) 2010 NXP Semiconductors
   9  * Copyright (C) 2012 Roland Stigge
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  *
  22  * This controller supports square key matrices from 1x1 up to 8x8
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/slab.h>
  28 #include <linux/irq.h>
  29 #include <linux/pm.h>
  30 #include <linux/platform_device.h>
  31 #include <linux/input.h>
  32 #include <linux/clk.h>
  33 #include <linux/io.h>
  34 #include <linux/of.h>
  35 #include <linux/input/matrix_keypad.h>
  36
  37 #define DRV_NAME                                "lpc32xx_keys"
  38
  39 /*
  40  * Key scanner register offsets
  41  */
  42 #define LPC32XX_KS_DEB(x)                       ((x) + 0x00)
  43 #define LPC32XX_KS_STATE_COND(x)                ((x) + 0x04)
  44 #define LPC32XX_KS_IRQ(x)                       ((x) + 0x08)
  45 #define LPC32XX_KS_SCAN_CTL(x)                  ((x) + 0x0C)
  46 #define LPC32XX_KS_FAST_TST(x)                  ((x) + 0x10)
  47 #define LPC32XX_KS_MATRIX_DIM(x)                ((x) + 0x14) /* 1..8 */
  48 #define LPC32XX_KS_DATA(x, y)                   ((x) + 0x40 + ((y) << 2))
  49
  50 #define LPC32XX_KSCAN_DEB_NUM_DEB_PASS(n)       ((n) & 0xFF)
  51
  52 #define LPC32XX_KSCAN_SCOND_IN_IDLE             0x0
  53 #define LPC32XX_KSCAN_SCOND_IN_SCANONCE         0x1
  54 #define LPC32XX_KSCAN_SCOND_IN_IRQGEN           0x2
  55 #define LPC32XX_KSCAN_SCOND_IN_SCAN_MATRIX      0x3
  56
  57 #define LPC32XX_KSCAN_IRQ_PENDING_CLR           0x1
  58
  59 #define LPC32XX_KSCAN_SCTRL_SCAN_DELAY(n)       ((n) & 0xFF)
  60
  61 #define LPC32XX_KSCAN_FTST_FORCESCANONCE        0x1
  62 #define LPC32XX_KSCAN_FTST_USE32K_CLK           0x2
  63
  64 #define LPC32XX_KSCAN_MSEL_SELECT(n)            ((n) & 0xF)
  65
  66 struct lpc32xx_kscan_drv {
  67         struct input_dev *input;
  68         struct clk *clk;
  69         struct resource *iores;
  70         void __iomem *kscan_base;
  71         unsigned int irq;
  72
  73         u32 matrix_sz;          /* Size of matrix in XxY, ie. 3 = 3x3 */
  74         u32 deb_clks;           /* Debounce clocks (based on 32KHz clock) */
  75         u32 scan_delay;         /* Scan delay (based on 32KHz clock) */
  76
  77         unsigned short *keymap; /* Pointer to key map for the scan matrix */
  78         unsigned int row_shift;
  79
  80         u8 lastkeystates[8];
  81 };
  82
  83 static void lpc32xx_mod_states(struct lpc32xx_kscan_drv *kscandat, int col)
  84 {
  85         struct input_dev *input = kscandat->input;
  86         unsigned row, changed, scancode, keycode;
  87         u8 key;
  88
  89         key = readl(LPC32XX_KS_DATA(kscandat->kscan_base, col));
  90         changed = key ^ kscandat->lastkeystates[col];
  91         kscandat->lastkeystates[col] = key;
  92
  93         for (row = 0; changed; row++, changed >>= 1) {
  94                 if (changed & 1) {
  95                         /* Key state changed, signal an event */
  96                         scancode = MATRIX_SCAN_CODE(row, col,
  97                                                     kscandat->row_shift);
  98                         keycode = kscandat->keymap[scancode];
  99                         input_event(input, EV_MSC, MSC_SCAN, scancode);
 100                         input_report_key(input, keycode, key & (1 << row));
 101                 }
 102         }
 103 }
 104
 105 static irqreturn_t lpc32xx_kscan_irq(int irq, void *dev_id)
 106 {
 107         struct lpc32xx_kscan_drv *kscandat = dev_id;
 108         int i;
 109
 110         for (i = 0; i < kscandat->matrix_sz; i++)
 111                 lpc32xx_mod_states(kscandat, i);
 112
 113         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
 114
 115         input_sync(kscandat->input);
 116
 117         return IRQ_HANDLED;
 118 }
 119
 120 static int lpc32xx_kscan_open(struct input_dev *dev)
 121 {
 122         struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);
 123         int error;
 124
 125         error = clk_prepare_enable(kscandat->clk);
 126         if (error)
 127                 return error;
 128
 129         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
 130
 131         return 0;
 132 }
 133
 134 static void lpc32xx_kscan_close(struct input_dev *dev)
 135 {
 136         struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);
 137
 138         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
 139         clk_disable_unprepare(kscandat->clk);
 140 }
 141
 142 static int lpc32xx_parse_dt(struct device *dev,
 143                                       struct lpc32xx_kscan_drv *kscandat)
 144 {
 145         struct device_node *np = dev->of_node;
 146         u32 rows = 0, columns = 0;
 147         int err;
 148
 149         err = matrix_keypad_parse_of_params(dev, &rows, &columns);
 150         if (err)
 151                 return err;
 152         if (rows != columns) {
 153                 dev_err(dev, "rows and columns must be equal!\n");
 154                 return -EINVAL;
 155         }
 156
 157         kscandat->matrix_sz = rows;
 158         kscandat->row_shift = get_count_order(columns);
 159
 160         of_property_read_u32(np, "nxp,debounce-delay-ms", &kscandat->deb_clks);
 161         of_property_read_u32(np, "nxp,scan-delay-ms", &kscandat->scan_delay);
 162         if (!kscandat->deb_clks || !kscandat->scan_delay) {
 163                 dev_err(dev, "debounce or scan delay not specified\n");
 164                 return -EINVAL;
 165         }
 166
 167         return 0;
 168 }
 169
 170 static int lpc32xx_kscan_probe(struct platform_device *pdev)
 171 {
 172         struct lpc32xx_kscan_drv *kscandat;
 173         struct input_dev *input;
 174         struct resource *res;
 175         size_t keymap_size;
 176         int error;
 177         int irq;
 178
 179         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 180         if (!res) {
 181                 dev_err(&pdev->dev, "failed to get platform I/O memory\n");
 182                 return -EINVAL;
 183         }
 184
 185         irq = platform_get_irq(pdev, 0);
 186         if (irq < 0 || irq >= NR_IRQS) {
 187                 dev_err(&pdev->dev, "failed to get platform irq\n");
 188                 return -EINVAL;
 189         }
 190
 191         kscandat = kzalloc(sizeof(struct lpc32xx_kscan_drv), GFP_KERNEL);
 192         if (!kscandat) {
 193                 dev_err(&pdev->dev, "failed to allocate memory\n");
 194                 return -ENOMEM;
 195         }
 196
 197         error = lpc32xx_parse_dt(&pdev->dev, kscandat);
 198         if (error) {
 199                 dev_err(&pdev->dev, "failed to parse device tree\n");
 200                 goto err_free_mem;
 201         }
 202
 203         keymap_size = sizeof(kscandat->keymap[0]) *
 204                                 (kscandat->matrix_sz << kscandat->row_shift);
 205         kscandat->keymap = kzalloc(keymap_size, GFP_KERNEL);
 206         if (!kscandat->keymap) {
 207                 dev_err(&pdev->dev, "could not allocate memory for keymap\n");
 208                 error = -ENOMEM;
 209                 goto err_free_mem;
 210         }
 211
 212         kscandat->input = input = input_allocate_device();
 213         if (!input) {
 214                 dev_err(&pdev->dev, "failed to allocate input device\n");
 215                 error = -ENOMEM;
 216                 goto err_free_keymap;
 217         }
 218
 219         /* Setup key input */
 220         input->name             = pdev->name;
 221         input->phys             = "lpc32xx/input0";
 222         input->id.vendor        = 0x0001;
 223         input->id.product       = 0x0001;
 224         input->id.version       = 0x0100;
 225         input->open             = lpc32xx_kscan_open;
 226         input->close            = lpc32xx_kscan_close;
 227         input->dev.parent       = &pdev->dev;
 228
 229         input_set_capability(input, EV_MSC, MSC_SCAN);
 230
 231         error = matrix_keypad_build_keymap(NULL, NULL,
 232                                            kscandat->matrix_sz,
 233                                            kscandat->matrix_sz,
 234                                            kscandat->keymap, kscandat->input);
 235         if (error) {
 236                 dev_err(&pdev->dev, "failed to build keymap\n");
 237                 goto err_free_input;
 238         }
 239
 240         input_set_drvdata(kscandat->input, kscandat);
 241
 242         kscandat->iores = request_mem_region(res->start, resource_size(res),
 243                                              pdev->name);
 244         if (!kscandat->iores) {
 245                 dev_err(&pdev->dev, "failed to request I/O memory\n");
 246                 error = -EBUSY;
 247                 goto err_free_input;
 248         }
 249
 250         kscandat->kscan_base = ioremap(kscandat->iores->start,
 251                                        resource_size(kscandat->iores));
 252         if (!kscandat->kscan_base) {
 253                 dev_err(&pdev->dev, "failed to remap I/O memory\n");
 254                 error = -EBUSY;
 255                 goto err_release_memregion;
 256         }
 257
 258         /* Get the key scanner clock */
 259         kscandat->clk = clk_get(&pdev->dev, NULL);
 260         if (IS_ERR(kscandat->clk)) {
 261                 dev_err(&pdev->dev, "failed to get clock\n");
 262                 error = PTR_ERR(kscandat->clk);
 263                 goto err_unmap;
 264         }
 265
 266         /* Configure the key scanner */
 267         error = clk_prepare_enable(kscandat->clk);
 268         if (error)
 269                 goto err_clk_put;
 270
 271         writel(kscandat->deb_clks, LPC32XX_KS_DEB(kscandat->kscan_base));
 272         writel(kscandat->scan_delay, LPC32XX_KS_SCAN_CTL(kscandat->kscan_base));
 273         writel(LPC32XX_KSCAN_FTST_USE32K_CLK,
 274                LPC32XX_KS_FAST_TST(kscandat->kscan_base));
 275         writel(kscandat->matrix_sz,
 276                LPC32XX_KS_MATRIX_DIM(kscandat->kscan_base));
 277         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
 278         clk_disable_unprepare(kscandat->clk);
 279
 280         error = request_irq(irq, lpc32xx_kscan_irq, 0, pdev->name, kscandat);
 281         if (error) {
 282                 dev_err(&pdev->dev, "failed to request irq\n");
 283                 goto err_clk_put;
 284         }
 285
 286         error = input_register_device(kscandat->input);
 287         if (error) {
 288                 dev_err(&pdev->dev, "failed to register input device\n");
 289                 goto err_free_irq;
 290         }
 291
 292         platform_set_drvdata(pdev, kscandat);
 293         return 0;
 294
 295 err_free_irq:
 296         free_irq(irq, kscandat);
 297 err_clk_put:
 298         clk_put(kscandat->clk);
 299 err_unmap:
 300         iounmap(kscandat->kscan_base);
 301 err_release_memregion:
 302         release_mem_region(kscandat->iores->start,
 303                            resource_size(kscandat->iores));
 304 err_free_input:
 305         input_free_device(kscandat->input);
 306 err_free_keymap:
 307         kfree(kscandat->keymap);
 308 err_free_mem:
 309         kfree(kscandat);
 310
 311         return error;
 312 }
 313
 314 static int lpc32xx_kscan_remove(struct platform_device *pdev)
 315 {
 316         struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
 317
 318         free_irq(platform_get_irq(pdev, 0), kscandat);
 319         clk_put(kscandat->clk);
 320         iounmap(kscandat->kscan_base);
 321         release_mem_region(kscandat->iores->start,
 322                            resource_size(kscandat->iores));
 323         input_unregister_device(kscandat->input);
 324         kfree(kscandat->keymap);
 325         kfree(kscandat);
 326
 327         return 0;
 328 }
 329
 330 #ifdef CONFIG_PM_SLEEP
 331 static int lpc32xx_kscan_suspend(struct device *dev)
 332 {
 333         struct platform_device *pdev = to_platform_device(dev);
 334         struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
 335         struct input_dev *input = kscandat->input;
 336
 337         mutex_lock(&input->mutex);
 338
 339         if (input->users) {
 340                 /* Clear IRQ and disable clock */
 341                 writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
 342                 clk_disable_unprepare(kscandat->clk);
 343         }
 344
 345         mutex_unlock(&input->mutex);
 346         return 0;
 347 }
 348
 349 static int lpc32xx_kscan_resume(struct device *dev)
 350 {
 351         struct platform_device *pdev = to_platform_device(dev);
 352         struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
 353         struct input_dev *input = kscandat->input;
 354         int retval = 0;
 355
 356         mutex_lock(&input->mutex);
 357
 358         if (input->users) {
 359                 /* Enable clock and clear IRQ */
 360                 retval = clk_prepare_enable(kscandat->clk);
 361                 if (retval == 0)
 362                         writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
 363         }
 364
 365         mutex_unlock(&input->mutex);
 366         return retval;
 367 }
 368 #endif
 369
 370 static SIMPLE_DEV_PM_OPS(lpc32xx_kscan_pm_ops, lpc32xx_kscan_suspend,
 371                          lpc32xx_kscan_resume);
 372
 373 static const struct of_device_id lpc32xx_kscan_match[] = {
 374         { .compatible = "nxp,lpc3220-key" },
 375         {},
 376 };
 377 MODULE_DEVICE_TABLE(of, lpc32xx_kscan_match);
 378
 379 static struct platform_driver lpc32xx_kscan_driver = {
 380         .probe          = lpc32xx_kscan_probe,
 381         .remove         = lpc32xx_kscan_remove,
 382         .driver         = {
 383                 .name   = DRV_NAME,
 384                 .owner  = THIS_MODULE,
 385                 .pm     = &lpc32xx_kscan_pm_ops,
 386                 .of_match_table = of_match_ptr(lpc32xx_kscan_match),
 387         }
 388 };
 389
 390 module_platform_driver(lpc32xx_kscan_driver);
 391
 392 MODULE_LICENSE("GPL");
 393 MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
 394 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
 395 MODULE_DESCRIPTION("Key scanner driver for LPC32XX devices");