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