drivers/input/keyboard/spear-keyboard.c

   1 /*
   2  * SPEAr Keyboard Driver
   3  * Based on omap-keypad driver
   4  *
   5  * Copyright (C) 2010 ST Microelectronics
   6  * Rajeev Kumar <rajeevkumar.linux@gmail.com>
   7  *
   8  * This file is licensed under the terms of the GNU General Public
   9  * License version 2. This program is licensed "as is" without any
  10  * warranty of any kind, whether express or implied.
  11  */
  12
  13 #include <linux/clk.h>
  14 #include <linux/errno.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/input.h>
  17 #include <linux/io.h>
  18 #include <linux/irq.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/of.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/pm_wakeup.h>
  24 #include <linux/slab.h>
  25 #include <linux/types.h>
  26 #include <linux/platform_data/keyboard-spear.h>
  27
  28 /* Keyboard Registers */
  29 #define MODE_CTL_REG    0x00
  30 #define STATUS_REG      0x0C
  31 #define DATA_REG        0x10
  32 #define INTR_MASK       0x54
  33
  34 /* Register Values */
  35 #define NUM_ROWS        16
  36 #define NUM_COLS        16
  37 #define MODE_CTL_PCLK_FREQ_SHIFT        9
  38 #define MODE_CTL_PCLK_FREQ_MSK          0x7F
  39
  40 #define MODE_CTL_KEYBOARD       (0x2 << 0)
  41 #define MODE_CTL_SCAN_RATE_10   (0x0 << 2)
  42 #define MODE_CTL_SCAN_RATE_20   (0x1 << 2)
  43 #define MODE_CTL_SCAN_RATE_40   (0x2 << 2)
  44 #define MODE_CTL_SCAN_RATE_80   (0x3 << 2)
  45 #define MODE_CTL_KEYNUM_SHIFT   6
  46 #define MODE_CTL_START_SCAN     (0x1 << 8)
  47
  48 #define STATUS_DATA_AVAIL       (0x1 << 1)
  49
  50 #define DATA_ROW_MASK           0xF0
  51 #define DATA_COLUMN_MASK        0x0F
  52
  53 #define ROW_SHIFT               4
  54
  55 struct spear_kbd {
  56         struct input_dev *input;
  57         void __iomem *io_base;
  58         struct clk *clk;
  59         unsigned int irq;
  60         unsigned int mode;
  61         unsigned int suspended_rate;
  62         unsigned short last_key;
  63         unsigned short keycodes[NUM_ROWS * NUM_COLS];
  64         bool rep;
  65         bool irq_wake_enabled;
  66         u32 mode_ctl_reg;
  67 };
  68
  69 static irqreturn_t spear_kbd_interrupt(int irq, void *dev_id)
  70 {
  71         struct spear_kbd *kbd = dev_id;
  72         struct input_dev *input = kbd->input;
  73         unsigned int key;
  74         u32 sts, val;
  75
  76         sts = readl_relaxed(kbd->io_base + STATUS_REG);
  77         if (!(sts & STATUS_DATA_AVAIL))
  78                 return IRQ_NONE;
  79
  80         if (kbd->last_key != KEY_RESERVED) {
  81                 input_report_key(input, kbd->last_key, 0);
  82                 kbd->last_key = KEY_RESERVED;
  83         }
  84
  85         /* following reads active (row, col) pair */
  86         val = readl_relaxed(kbd->io_base + DATA_REG) &
  87                 (DATA_ROW_MASK | DATA_COLUMN_MASK);
  88         key = kbd->keycodes[val];
  89
  90         input_event(input, EV_MSC, MSC_SCAN, val);
  91         input_report_key(input, key, 1);
  92         input_sync(input);
  93
  94         kbd->last_key = key;
  95
  96         /* clear interrupt */
  97         writel_relaxed(0, kbd->io_base + STATUS_REG);
  98
  99         return IRQ_HANDLED;
 100 }
 101
 102 static int spear_kbd_open(struct input_dev *dev)
 103 {
 104         struct spear_kbd *kbd = input_get_drvdata(dev);
 105         int error;
 106         u32 val;
 107
 108         kbd->last_key = KEY_RESERVED;
 109
 110         error = clk_enable(kbd->clk);
 111         if (error)
 112                 return error;
 113
 114         /* keyboard rate to be programmed is input clock (in MHz) - 1 */
 115         val = clk_get_rate(kbd->clk) / 1000000 - 1;
 116         val = (val & MODE_CTL_PCLK_FREQ_MSK) << MODE_CTL_PCLK_FREQ_SHIFT;
 117
 118         /* program keyboard */
 119         val = MODE_CTL_SCAN_RATE_80 | MODE_CTL_KEYBOARD | val |
 120                 (kbd->mode << MODE_CTL_KEYNUM_SHIFT);
 121         writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
 122         writel_relaxed(1, kbd->io_base + STATUS_REG);
 123
 124         /* start key scan */
 125         val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
 126         val |= MODE_CTL_START_SCAN;
 127         writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
 128
 129         return 0;
 130 }
 131
 132 static void spear_kbd_close(struct input_dev *dev)
 133 {
 134         struct spear_kbd *kbd = input_get_drvdata(dev);
 135         u32 val;
 136
 137         /* stop key scan */
 138         val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
 139         val &= ~MODE_CTL_START_SCAN;
 140         writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
 141
 142         clk_disable(kbd->clk);
 143
 144         kbd->last_key = KEY_RESERVED;
 145 }
 146
 147 #ifdef CONFIG_OF
 148 static int spear_kbd_parse_dt(struct platform_device *pdev,
 149                                         struct spear_kbd *kbd)
 150 {
 151         struct device_node *np = pdev->dev.of_node;
 152         int error;
 153         u32 val, suspended_rate;
 154
 155         if (!np) {
 156                 dev_err(&pdev->dev, "Missing DT data\n");
 157                 return -EINVAL;
 158         }
 159
 160         if (of_property_read_bool(np, "autorepeat"))
 161                 kbd->rep = true;
 162
 163         if (of_property_read_u32(np, "suspended_rate", &suspended_rate))
 164                 kbd->suspended_rate = suspended_rate;
 165
 166         error = of_property_read_u32(np, "st,mode", &val);
 167         if (error) {
 168                 dev_err(&pdev->dev, "DT: Invalid or missing mode\n");
 169                 return error;
 170         }
 171
 172         kbd->mode = val;
 173         return 0;
 174 }
 175 #else
 176 static inline int spear_kbd_parse_dt(struct platform_device *pdev,
 177                                      struct spear_kbd *kbd)
 178 {
 179         return -ENOSYS;
 180 }
 181 #endif
 182
 183 static int spear_kbd_probe(struct platform_device *pdev)
 184 {
 185         struct kbd_platform_data *pdata = dev_get_platdata(&pdev->dev);
 186         const struct matrix_keymap_data *keymap = pdata ? pdata->keymap : NULL;
 187         struct spear_kbd *kbd;
 188         struct input_dev *input_dev;
 189         struct resource *res;
 190         int irq;
 191         int error;
 192
 193         irq = platform_get_irq(pdev, 0);
 194         if (irq < 0) {
 195                 dev_err(&pdev->dev, "not able to get irq for the device\n");
 196                 return irq;
 197         }
 198
 199         kbd = devm_kzalloc(&pdev->dev, sizeof(*kbd), GFP_KERNEL);
 200         if (!kbd) {
 201                 dev_err(&pdev->dev, "not enough memory for driver data\n");
 202                 return -ENOMEM;
 203         }
 204
 205         input_dev = devm_input_allocate_device(&pdev->dev);
 206         if (!input_dev) {
 207                 dev_err(&pdev->dev, "unable to allocate input device\n");
 208                 return -ENOMEM;
 209         }
 210
 211         kbd->input = input_dev;
 212         kbd->irq = irq;
 213
 214         if (!pdata) {
 215                 error = spear_kbd_parse_dt(pdev, kbd);
 216                 if (error)
 217                         return error;
 218         } else {
 219                 kbd->mode = pdata->mode;
 220                 kbd->rep = pdata->rep;
 221                 kbd->suspended_rate = pdata->suspended_rate;
 222         }
 223
 224         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 225         kbd->io_base = devm_ioremap_resource(&pdev->dev, res);
 226         if (IS_ERR(kbd->io_base))
 227                 return PTR_ERR(kbd->io_base);
 228
 229         kbd->clk = devm_clk_get(&pdev->dev, NULL);
 230         if (IS_ERR(kbd->clk))
 231                 return PTR_ERR(kbd->clk);
 232
 233         input_dev->name = "Spear Keyboard";
 234         input_dev->phys = "keyboard/input0";
 235         input_dev->id.bustype = BUS_HOST;
 236         input_dev->id.vendor = 0x0001;
 237         input_dev->id.product = 0x0001;
 238         input_dev->id.version = 0x0100;
 239         input_dev->open = spear_kbd_open;
 240         input_dev->close = spear_kbd_close;
 241
 242         error = matrix_keypad_build_keymap(keymap, NULL, NUM_ROWS, NUM_COLS,
 243                                            kbd->keycodes, input_dev);
 244         if (error) {
 245                 dev_err(&pdev->dev, "Failed to build keymap\n");
 246                 return error;
 247         }
 248
 249         if (kbd->rep)
 250                 __set_bit(EV_REP, input_dev->evbit);
 251         input_set_capability(input_dev, EV_MSC, MSC_SCAN);
 252
 253         input_set_drvdata(input_dev, kbd);
 254
 255         error = devm_request_irq(&pdev->dev, irq, spear_kbd_interrupt, 0,
 256                         "keyboard", kbd);
 257         if (error) {
 258                 dev_err(&pdev->dev, "request_irq failed\n");
 259                 return error;
 260         }
 261
 262         error = clk_prepare(kbd->clk);
 263         if (error)
 264                 return error;
 265
 266         error = input_register_device(input_dev);
 267         if (error) {
 268                 dev_err(&pdev->dev, "Unable to register keyboard device\n");
 269                 clk_unprepare(kbd->clk);
 270                 return error;
 271         }
 272
 273         device_init_wakeup(&pdev->dev, 1);
 274         platform_set_drvdata(pdev, kbd);
 275
 276         return 0;
 277 }
 278
 279 static int spear_kbd_remove(struct platform_device *pdev)
 280 {
 281         struct spear_kbd *kbd = platform_get_drvdata(pdev);
 282
 283         input_unregister_device(kbd->input);
 284         clk_unprepare(kbd->clk);
 285
 286         return 0;
 287 }
 288
 289 static int __maybe_unused spear_kbd_suspend(struct device *dev)
 290 {
 291         struct platform_device *pdev = to_platform_device(dev);
 292         struct spear_kbd *kbd = platform_get_drvdata(pdev);
 293         struct input_dev *input_dev = kbd->input;
 294         unsigned int rate = 0, mode_ctl_reg, val;
 295
 296         mutex_lock(&input_dev->mutex);
 297
 298         /* explicitly enable clock as we may program device */
 299         clk_enable(kbd->clk);
 300
 301         mode_ctl_reg = readl_relaxed(kbd->io_base + MODE_CTL_REG);
 302
 303         if (device_may_wakeup(&pdev->dev)) {
 304                 if (!enable_irq_wake(kbd->irq))
 305                         kbd->irq_wake_enabled = true;
 306
 307                 /*
 308                  * reprogram the keyboard operating frequency as on some
 309                  * platform it may change during system suspended
 310                  */
 311                 if (kbd->suspended_rate)
 312                         rate = kbd->suspended_rate / 1000000 - 1;
 313                 else
 314                         rate = clk_get_rate(kbd->clk) / 1000000 - 1;
 315
 316                 val = mode_ctl_reg &
 317                         ~(MODE_CTL_PCLK_FREQ_MSK << MODE_CTL_PCLK_FREQ_SHIFT);
 318                 val |= (rate & MODE_CTL_PCLK_FREQ_MSK)
 319                         << MODE_CTL_PCLK_FREQ_SHIFT;
 320                 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
 321
 322         } else {
 323                 if (input_dev->users) {
 324                         writel_relaxed(mode_ctl_reg & ~MODE_CTL_START_SCAN,
 325                                         kbd->io_base + MODE_CTL_REG);
 326                         clk_disable(kbd->clk);
 327                 }
 328         }
 329
 330         /* store current configuration */
 331         if (input_dev->users)
 332                 kbd->mode_ctl_reg = mode_ctl_reg;
 333
 334         /* restore previous clk state */
 335         clk_disable(kbd->clk);
 336
 337         mutex_unlock(&input_dev->mutex);
 338
 339         return 0;
 340 }
 341
 342 static int __maybe_unused spear_kbd_resume(struct device *dev)
 343 {
 344         struct platform_device *pdev = to_platform_device(dev);
 345         struct spear_kbd *kbd = platform_get_drvdata(pdev);
 346         struct input_dev *input_dev = kbd->input;
 347
 348         mutex_lock(&input_dev->mutex);
 349
 350         if (device_may_wakeup(&pdev->dev)) {
 351                 if (kbd->irq_wake_enabled) {
 352                         kbd->irq_wake_enabled = false;
 353                         disable_irq_wake(kbd->irq);
 354                 }
 355         } else {
 356                 if (input_dev->users)
 357                         clk_enable(kbd->clk);
 358         }
 359
 360         /* restore current configuration */
 361         if (input_dev->users)
 362                 writel_relaxed(kbd->mode_ctl_reg, kbd->io_base + MODE_CTL_REG);
 363
 364         mutex_unlock(&input_dev->mutex);
 365
 366         return 0;
 367 }
 368
 369 static SIMPLE_DEV_PM_OPS(spear_kbd_pm_ops, spear_kbd_suspend, spear_kbd_resume);
 370
 371 #ifdef CONFIG_OF
 372 static const struct of_device_id spear_kbd_id_table[] = {
 373         { .compatible = "st,spear300-kbd" },
 374         {}
 375 };
 376 MODULE_DEVICE_TABLE(of, spear_kbd_id_table);
 377 #endif
 378
 379 static struct platform_driver spear_kbd_driver = {
 380         .probe          = spear_kbd_probe,
 381         .remove         = spear_kbd_remove,
 382         .driver         = {
 383                 .name   = "keyboard",
 384                 .pm     = &spear_kbd_pm_ops,
 385                 .of_match_table = of_match_ptr(spear_kbd_id_table),
 386         },
 387 };
 388 module_platform_driver(spear_kbd_driver);
 389
 390 MODULE_AUTHOR("Rajeev Kumar");
 391 MODULE_DESCRIPTION("SPEAr Keyboard Driver");
 392 MODULE_LICENSE("GPL");