linux/drivers/input/keyboard/spear-keyboard.c
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   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
  55struct 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
  69static 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
 102static 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
 132static 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
 148static 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
 176static inline int spear_kbd_parse_dt(struct platform_device *pdev,
 177                                     struct spear_kbd *kbd)
 178{
 179        return -ENOSYS;
 180}
 181#endif
 182
 183static 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
 279static 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
 289static 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
 342static 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
 369static SIMPLE_DEV_PM_OPS(spear_kbd_pm_ops, spear_kbd_suspend, spear_kbd_resume);
 370
 371#ifdef CONFIG_OF
 372static const struct of_device_id spear_kbd_id_table[] = {
 373        { .compatible = "st,spear300-kbd" },
 374        {}
 375};
 376MODULE_DEVICE_TABLE(of, spear_kbd_id_table);
 377#endif
 378
 379static 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};
 388module_platform_driver(spear_kbd_driver);
 389
 390MODULE_AUTHOR("Rajeev Kumar");
 391MODULE_DESCRIPTION("SPEAr Keyboard Driver");
 392MODULE_LICENSE("GPL");
 393