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<rajeev-dlh.kumar@st.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/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/input.h>
  18 #include <linux/io.h>
  19 #include <linux/irq.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/of.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/pm_wakeup.h>
  25 #include <linux/slab.h>
  26 #include <linux/types.h>
  27 #include <linux/platform_data/keyboard-spear.h>
  28
  29 /* Keyboard Registers */
  30 #define MODE_CTL_REG    0x00
  31 #define STATUS_REG      0x0C
  32 #define DATA_REG        0x10
  33 #define INTR_MASK       0x54
  34
  35 /* Register Values */
  36 #define NUM_ROWS        16
  37 #define NUM_COLS        16
  38 #define MODE_CTL_PCLK_FREQ_SHIFT        9
  39 #define MODE_CTL_PCLK_FREQ_MSK          0x7F
  40
  41 #define MODE_CTL_KEYBOARD       (0x2 << 0)
  42 #define MODE_CTL_SCAN_RATE_10   (0x0 << 2)
  43 #define MODE_CTL_SCAN_RATE_20   (0x1 << 2)
  44 #define MODE_CTL_SCAN_RATE_40   (0x2 << 2)
  45 #define MODE_CTL_SCAN_RATE_80   (0x3 << 2)
  46 #define MODE_CTL_KEYNUM_SHIFT   6
  47 #define MODE_CTL_START_SCAN     (0x1 << 8)
  48
  49 #define STATUS_DATA_AVAIL       (0x1 << 1)
  50
  51 #define DATA_ROW_MASK           0xF0
  52 #define DATA_COLUMN_MASK        0x0F
  53
  54 #define ROW_SHIFT               4
  55
  56 struct spear_kbd {
  57         struct input_dev *input;
  58         void __iomem *io_base;
  59         struct clk *clk;
  60         unsigned int irq;
  61         unsigned int mode;
  62         unsigned int suspended_rate;
  63         unsigned short last_key;
  64         unsigned short keycodes[NUM_ROWS * NUM_COLS];
  65         bool rep;
  66         bool irq_wake_enabled;
  67         u32 mode_ctl_reg;
  68 };
  69
  70 static irqreturn_t spear_kbd_interrupt(int irq, void *dev_id)
  71 {
  72         struct spear_kbd *kbd = dev_id;
  73         struct input_dev *input = kbd->input;
  74         unsigned int key;
  75         u32 sts, val;
  76
  77         sts = readl_relaxed(kbd->io_base + STATUS_REG);
  78         if (!(sts & STATUS_DATA_AVAIL))
  79                 return IRQ_NONE;
  80
  81         if (kbd->last_key != KEY_RESERVED) {
  82                 input_report_key(input, kbd->last_key, 0);
  83                 kbd->last_key = KEY_RESERVED;
  84         }
  85
  86         /* following reads active (row, col) pair */
  87         val = readl_relaxed(kbd->io_base + DATA_REG) &
  88                 (DATA_ROW_MASK | DATA_COLUMN_MASK);
  89         key = kbd->keycodes[val];
  90
  91         input_event(input, EV_MSC, MSC_SCAN, val);
  92         input_report_key(input, key, 1);
  93         input_sync(input);
  94
  95         kbd->last_key = key;
  96
  97         /* clear interrupt */
  98         writel_relaxed(0, kbd->io_base + STATUS_REG);
  99
 100         return IRQ_HANDLED;
 101 }
 102
 103 static int spear_kbd_open(struct input_dev *dev)
 104 {
 105         struct spear_kbd *kbd = input_get_drvdata(dev);
 106         int error;
 107         u32 val;
 108
 109         kbd->last_key = KEY_RESERVED;
 110
 111         error = clk_enable(kbd->clk);
 112         if (error)
 113                 return error;
 114
 115         /* keyboard rate to be programmed is input clock (in MHz) - 1 */
 116         val = clk_get_rate(kbd->clk) / 1000000 - 1;
 117         val = (val & MODE_CTL_PCLK_FREQ_MSK) << MODE_CTL_PCLK_FREQ_SHIFT;
 118
 119         /* program keyboard */
 120         val = MODE_CTL_SCAN_RATE_80 | MODE_CTL_KEYBOARD | val |
 121                 (kbd->mode << MODE_CTL_KEYNUM_SHIFT);
 122         writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
 123         writel_relaxed(1, kbd->io_base + STATUS_REG);
 124
 125         /* start key scan */
 126         val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
 127         val |= MODE_CTL_START_SCAN;
 128         writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
 129
 130         return 0;
 131 }
 132
 133 static void spear_kbd_close(struct input_dev *dev)
 134 {
 135         struct spear_kbd *kbd = input_get_drvdata(dev);
 136         u32 val;
 137
 138         /* stop key scan */
 139         val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
 140         val &= ~MODE_CTL_START_SCAN;
 141         writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
 142
 143         clk_disable(kbd->clk);
 144
 145         kbd->last_key = KEY_RESERVED;
 146 }
 147
 148 #ifdef CONFIG_OF
 149 static int spear_kbd_parse_dt(struct platform_device *pdev,
 150                                         struct spear_kbd *kbd)
 151 {
 152         struct device_node *np = pdev->dev.of_node;
 153         int error;
 154         u32 val, suspended_rate;
 155
 156         if (!np) {
 157                 dev_err(&pdev->dev, "Missing DT data\n");
 158                 return -EINVAL;
 159         }
 160
 161         if (of_property_read_bool(np, "autorepeat"))
 162                 kbd->rep = true;
 163
 164         if (of_property_read_u32(np, "suspended_rate", &suspended_rate))
 165                 kbd->suspended_rate = suspended_rate;
 166
 167         error = of_property_read_u32(np, "st,mode", &val);
 168         if (error) {
 169                 dev_err(&pdev->dev, "DT: Invalid or missing mode\n");
 170                 return error;
 171         }
 172
 173         kbd->mode = val;
 174         return 0;
 175 }
 176 #else
 177 static inline int spear_kbd_parse_dt(struct platform_device *pdev,
 178                                      struct spear_kbd *kbd)
 179 {
 180         return -ENOSYS;
 181 }
 182 #endif
 183
 184 static int spear_kbd_probe(struct platform_device *pdev)
 185 {
 186         struct kbd_platform_data *pdata = dev_get_platdata(&pdev->dev);
 187         const struct matrix_keymap_data *keymap = pdata ? pdata->keymap : NULL;
 188         struct spear_kbd *kbd;
 189         struct input_dev *input_dev;
 190         struct resource *res;
 191         int irq;
 192         int error;
 193
 194         irq = platform_get_irq(pdev, 0);
 195         if (irq < 0) {
 196                 dev_err(&pdev->dev, "not able to get irq for the device\n");
 197                 return irq;
 198         }
 199
 200         kbd = devm_kzalloc(&pdev->dev, sizeof(*kbd), GFP_KERNEL);
 201         if (!kbd) {
 202                 dev_err(&pdev->dev, "not enough memory for driver data\n");
 203                 return -ENOMEM;
 204         }
 205
 206         input_dev = devm_input_allocate_device(&pdev->dev);
 207         if (!input_dev) {
 208                 dev_err(&pdev->dev, "unable to allocate input device\n");
 209                 return -ENOMEM;
 210         }
 211
 212         kbd->input = input_dev;
 213         kbd->irq = irq;
 214
 215         if (!pdata) {
 216                 error = spear_kbd_parse_dt(pdev, kbd);
 217                 if (error)
 218                         return error;
 219         } else {
 220                 kbd->mode = pdata->mode;
 221                 kbd->rep = pdata->rep;
 222                 kbd->suspended_rate = pdata->suspended_rate;
 223         }
 224
 225         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 226         kbd->io_base = devm_ioremap_resource(&pdev->dev, res);
 227         if (IS_ERR(kbd->io_base))
 228                 return PTR_ERR(kbd->io_base);
 229
 230         kbd->clk = devm_clk_get(&pdev->dev, NULL);
 231         if (IS_ERR(kbd->clk))
 232                 return PTR_ERR(kbd->clk);
 233
 234         input_dev->name = "Spear Keyboard";
 235         input_dev->phys = "keyboard/input0";
 236         input_dev->id.bustype = BUS_HOST;
 237         input_dev->id.vendor = 0x0001;
 238         input_dev->id.product = 0x0001;
 239         input_dev->id.version = 0x0100;
 240         input_dev->open = spear_kbd_open;
 241         input_dev->close = spear_kbd_close;
 242
 243         error = matrix_keypad_build_keymap(keymap, NULL, NUM_ROWS, NUM_COLS,
 244                                            kbd->keycodes, input_dev);
 245         if (error) {
 246                 dev_err(&pdev->dev, "Failed to build keymap\n");
 247                 return error;
 248         }
 249
 250         if (kbd->rep)
 251                 __set_bit(EV_REP, input_dev->evbit);
 252         input_set_capability(input_dev, EV_MSC, MSC_SCAN);
 253
 254         input_set_drvdata(input_dev, kbd);
 255
 256         error = devm_request_irq(&pdev->dev, irq, spear_kbd_interrupt, 0,
 257                         "keyboard", kbd);
 258         if (error) {
 259                 dev_err(&pdev->dev, "request_irq failed\n");
 260                 return error;
 261         }
 262
 263         error = clk_prepare(kbd->clk);
 264         if (error)
 265                 return error;
 266
 267         error = input_register_device(input_dev);
 268         if (error) {
 269                 dev_err(&pdev->dev, "Unable to register keyboard device\n");
 270                 clk_unprepare(kbd->clk);
 271                 return error;
 272         }
 273
 274         device_init_wakeup(&pdev->dev, 1);
 275         platform_set_drvdata(pdev, kbd);
 276
 277         return 0;
 278 }
 279
 280 static int spear_kbd_remove(struct platform_device *pdev)
 281 {
 282         struct spear_kbd *kbd = platform_get_drvdata(pdev);
 283
 284         input_unregister_device(kbd->input);
 285         clk_unprepare(kbd->clk);
 286
 287         device_init_wakeup(&pdev->dev, 0);
 288
 289         return 0;
 290 }
 291
 292 #ifdef CONFIG_PM
 293 static int spear_kbd_suspend(struct device *dev)
 294 {
 295         struct platform_device *pdev = to_platform_device(dev);
 296         struct spear_kbd *kbd = platform_get_drvdata(pdev);
 297         struct input_dev *input_dev = kbd->input;
 298         unsigned int rate = 0, mode_ctl_reg, val;
 299
 300         mutex_lock(&input_dev->mutex);
 301
 302         /* explicitly enable clock as we may program device */
 303         clk_enable(kbd->clk);
 304
 305         mode_ctl_reg = readl_relaxed(kbd->io_base + MODE_CTL_REG);
 306
 307         if (device_may_wakeup(&pdev->dev)) {
 308                 if (!enable_irq_wake(kbd->irq))
 309                         kbd->irq_wake_enabled = true;
 310
 311                 /*
 312                  * reprogram the keyboard operating frequency as on some
 313                  * platform it may change during system suspended
 314                  */
 315                 if (kbd->suspended_rate)
 316                         rate = kbd->suspended_rate / 1000000 - 1;
 317                 else
 318                         rate = clk_get_rate(kbd->clk) / 1000000 - 1;
 319
 320                 val = mode_ctl_reg &
 321                         ~(MODE_CTL_PCLK_FREQ_MSK << MODE_CTL_PCLK_FREQ_SHIFT);
 322                 val |= (rate & MODE_CTL_PCLK_FREQ_MSK)
 323                         << MODE_CTL_PCLK_FREQ_SHIFT;
 324                 writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
 325
 326         } else {
 327                 if (input_dev->users) {
 328                         writel_relaxed(mode_ctl_reg & ~MODE_CTL_START_SCAN,
 329                                         kbd->io_base + MODE_CTL_REG);
 330                         clk_disable(kbd->clk);
 331                 }
 332         }
 333
 334         /* store current configuration */
 335         if (input_dev->users)
 336                 kbd->mode_ctl_reg = mode_ctl_reg;
 337
 338         /* restore previous clk state */
 339         clk_disable(kbd->clk);
 340
 341         mutex_unlock(&input_dev->mutex);
 342
 343         return 0;
 344 }
 345
 346 static int spear_kbd_resume(struct device *dev)
 347 {
 348         struct platform_device *pdev = to_platform_device(dev);
 349         struct spear_kbd *kbd = platform_get_drvdata(pdev);
 350         struct input_dev *input_dev = kbd->input;
 351
 352         mutex_lock(&input_dev->mutex);
 353
 354         if (device_may_wakeup(&pdev->dev)) {
 355                 if (kbd->irq_wake_enabled) {
 356                         kbd->irq_wake_enabled = false;
 357                         disable_irq_wake(kbd->irq);
 358                 }
 359         } else {
 360                 if (input_dev->users)
 361                         clk_enable(kbd->clk);
 362         }
 363
 364         /* restore current configuration */
 365         if (input_dev->users)
 366                 writel_relaxed(kbd->mode_ctl_reg, kbd->io_base + MODE_CTL_REG);
 367
 368         mutex_unlock(&input_dev->mutex);
 369
 370         return 0;
 371 }
 372 #endif
 373
 374 static SIMPLE_DEV_PM_OPS(spear_kbd_pm_ops, spear_kbd_suspend, spear_kbd_resume);
 375
 376 #ifdef CONFIG_OF
 377 static const struct of_device_id spear_kbd_id_table[] = {
 378         { .compatible = "st,spear300-kbd" },
 379         {}
 380 };
 381 MODULE_DEVICE_TABLE(of, spear_kbd_id_table);
 382 #endif
 383
 384 static struct platform_driver spear_kbd_driver = {
 385         .probe          = spear_kbd_probe,
 386         .remove         = spear_kbd_remove,
 387         .driver         = {
 388                 .name   = "keyboard",
 389                 .owner  = THIS_MODULE,
 390                 .pm     = &spear_kbd_pm_ops,
 391                 .of_match_table = of_match_ptr(spear_kbd_id_table),
 392         },
 393 };
 394 module_platform_driver(spear_kbd_driver);
 395
 396 MODULE_AUTHOR("Rajeev Kumar");
 397 MODULE_DESCRIPTION("SPEAr Keyboard Driver");
 398 MODULE_LICENSE("GPL");