linux/drivers/input/keyboard/nomadik-ske-keypad.c
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   1/*
   2 * Copyright (C) ST-Ericsson SA 2010
   3 *
   4 * Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
   5 * Author: Sundar Iyer <sundar.iyer@stericsson.com> for ST-Ericsson
   6 *
   7 * License terms:GNU General Public License (GPL) version 2
   8 *
   9 * Keypad controller driver for the SKE (Scroll Key Encoder) module used in
  10 * the Nomadik 8815 and Ux500 platforms.
  11 */
  12
  13#include <linux/platform_device.h>
  14#include <linux/interrupt.h>
  15#include <linux/spinlock.h>
  16#include <linux/io.h>
  17#include <linux/delay.h>
  18#include <linux/input.h>
  19#include <linux/slab.h>
  20#include <linux/clk.h>
  21#include <linux/module.h>
  22
  23#include <linux/platform_data/keypad-nomadik-ske.h>
  24
  25/* SKE_CR bits */
  26#define SKE_KPMLT       (0x1 << 6)
  27#define SKE_KPCN        (0x7 << 3)
  28#define SKE_KPASEN      (0x1 << 2)
  29#define SKE_KPASON      (0x1 << 7)
  30
  31/* SKE_IMSC bits */
  32#define SKE_KPIMA       (0x1 << 2)
  33
  34/* SKE_ICR bits */
  35#define SKE_KPICS       (0x1 << 3)
  36#define SKE_KPICA       (0x1 << 2)
  37
  38/* SKE_RIS bits */
  39#define SKE_KPRISA      (0x1 << 2)
  40
  41#define SKE_KEYPAD_ROW_SHIFT    3
  42#define SKE_KPD_NUM_ROWS        8
  43#define SKE_KPD_NUM_COLS        8
  44
  45/* keypad auto scan registers */
  46#define SKE_ASR0        0x20
  47#define SKE_ASR1        0x24
  48#define SKE_ASR2        0x28
  49#define SKE_ASR3        0x2C
  50
  51#define SKE_NUM_ASRX_REGISTERS  (4)
  52#define KEY_PRESSED_DELAY       10
  53
  54/**
  55 * struct ske_keypad  - data structure used by keypad driver
  56 * @irq:        irq no
  57 * @reg_base:   ske registers base address
  58 * @input:      pointer to input device object
  59 * @board:      keypad platform device
  60 * @keymap:     matrix scan code table for keycodes
  61 * @clk:        clock structure pointer
  62 */
  63struct ske_keypad {
  64        int irq;
  65        void __iomem *reg_base;
  66        struct input_dev *input;
  67        const struct ske_keypad_platform_data *board;
  68        unsigned short keymap[SKE_KPD_NUM_ROWS * SKE_KPD_NUM_COLS];
  69        struct clk *clk;
  70        struct clk *pclk;
  71        spinlock_t ske_keypad_lock;
  72};
  73
  74static void ske_keypad_set_bits(struct ske_keypad *keypad, u16 addr,
  75                u8 mask, u8 data)
  76{
  77        u32 ret;
  78
  79        spin_lock(&keypad->ske_keypad_lock);
  80
  81        ret = readl(keypad->reg_base + addr);
  82        ret &= ~mask;
  83        ret |= data;
  84        writel(ret, keypad->reg_base + addr);
  85
  86        spin_unlock(&keypad->ske_keypad_lock);
  87}
  88
  89/*
  90 * ske_keypad_chip_init: init keypad controller configuration
  91 *
  92 * Enable Multi key press detection, auto scan mode
  93 */
  94static int __init ske_keypad_chip_init(struct ske_keypad *keypad)
  95{
  96        u32 value;
  97        int timeout = keypad->board->debounce_ms;
  98
  99        /* check SKE_RIS to be 0 */
 100        while ((readl(keypad->reg_base + SKE_RIS) != 0x00000000) && timeout--)
 101                cpu_relax();
 102
 103        if (!timeout)
 104                return -EINVAL;
 105
 106        /*
 107         * set debounce value
 108         * keypad dbounce is configured in DBCR[15:8]
 109         * dbounce value in steps of 32/32.768 ms
 110         */
 111        spin_lock(&keypad->ske_keypad_lock);
 112        value = readl(keypad->reg_base + SKE_DBCR);
 113        value = value & 0xff;
 114        value |= ((keypad->board->debounce_ms * 32000)/32768) << 8;
 115        writel(value, keypad->reg_base + SKE_DBCR);
 116        spin_unlock(&keypad->ske_keypad_lock);
 117
 118        /* enable multi key detection */
 119        ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPMLT);
 120
 121        /*
 122         * set up the number of columns
 123         * KPCN[5:3] defines no. of keypad columns to be auto scanned
 124         */
 125        value = (keypad->board->kcol - 1) << 3;
 126        ske_keypad_set_bits(keypad, SKE_CR, SKE_KPCN, value);
 127
 128        /* clear keypad interrupt for auto(and pending SW) scans */
 129        ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA | SKE_KPICS);
 130
 131        /* un-mask keypad interrupts */
 132        ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
 133
 134        /* enable automatic scan */
 135        ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPASEN);
 136
 137        return 0;
 138}
 139
 140static void ske_keypad_report(struct ske_keypad *keypad, u8 status, int col)
 141{
 142        int row = 0, code, pos;
 143        struct input_dev *input = keypad->input;
 144        u32 ske_ris;
 145        int key_pressed;
 146        int num_of_rows;
 147
 148        /* find out the row */
 149        num_of_rows = hweight8(status);
 150        do {
 151                pos = __ffs(status);
 152                row = pos;
 153                status &= ~(1 << pos);
 154
 155                code = MATRIX_SCAN_CODE(row, col, SKE_KEYPAD_ROW_SHIFT);
 156                ske_ris = readl(keypad->reg_base + SKE_RIS);
 157                key_pressed = ske_ris & SKE_KPRISA;
 158
 159                input_event(input, EV_MSC, MSC_SCAN, code);
 160                input_report_key(input, keypad->keymap[code], key_pressed);
 161                input_sync(input);
 162                num_of_rows--;
 163        } while (num_of_rows);
 164}
 165
 166static void ske_keypad_read_data(struct ske_keypad *keypad)
 167{
 168        u8 status;
 169        int col = 0;
 170        int ske_asr, i;
 171
 172        /*
 173         * Read the auto scan registers
 174         *
 175         * Each SKE_ASRx (x=0 to x=3) contains two row values.
 176         * lower byte contains row value for column 2*x,
 177         * upper byte contains row value for column 2*x + 1
 178         */
 179        for (i = 0; i < SKE_NUM_ASRX_REGISTERS; i++) {
 180                ske_asr = readl(keypad->reg_base + SKE_ASR0 + (4 * i));
 181                if (!ske_asr)
 182                        continue;
 183
 184                /* now that ASRx is zero, find out the coloumn x and row y */
 185                status = ske_asr & 0xff;
 186                if (status) {
 187                        col = i * 2;
 188                        ske_keypad_report(keypad, status, col);
 189                }
 190                status = (ske_asr & 0xff00) >> 8;
 191                if (status) {
 192                        col = (i * 2) + 1;
 193                        ske_keypad_report(keypad, status, col);
 194                }
 195        }
 196}
 197
 198static irqreturn_t ske_keypad_irq(int irq, void *dev_id)
 199{
 200        struct ske_keypad *keypad = dev_id;
 201        int timeout = keypad->board->debounce_ms;
 202
 203        /* disable auto scan interrupt; mask the interrupt generated */
 204        ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
 205        ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA);
 206
 207        while ((readl(keypad->reg_base + SKE_CR) & SKE_KPASON) && --timeout)
 208                cpu_relax();
 209
 210        /* SKEx registers are stable and can be read */
 211        ske_keypad_read_data(keypad);
 212
 213        /* wait until raw interrupt is clear */
 214        while ((readl(keypad->reg_base + SKE_RIS)) && --timeout)
 215                msleep(KEY_PRESSED_DELAY);
 216
 217        /* enable auto scan interrupts */
 218        ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
 219
 220        return IRQ_HANDLED;
 221}
 222
 223static int __init ske_keypad_probe(struct platform_device *pdev)
 224{
 225        const struct ske_keypad_platform_data *plat =
 226                        dev_get_platdata(&pdev->dev);
 227        struct ske_keypad *keypad;
 228        struct input_dev *input;
 229        struct resource *res;
 230        int irq;
 231        int error;
 232
 233        if (!plat) {
 234                dev_err(&pdev->dev, "invalid keypad platform data\n");
 235                return -EINVAL;
 236        }
 237
 238        irq = platform_get_irq(pdev, 0);
 239        if (irq < 0) {
 240                dev_err(&pdev->dev, "failed to get keypad irq\n");
 241                return -EINVAL;
 242        }
 243
 244        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 245        if (!res) {
 246                dev_err(&pdev->dev, "missing platform resources\n");
 247                return -EINVAL;
 248        }
 249
 250        keypad = kzalloc(sizeof(struct ske_keypad), GFP_KERNEL);
 251        input = input_allocate_device();
 252        if (!keypad || !input) {
 253                dev_err(&pdev->dev, "failed to allocate keypad memory\n");
 254                error = -ENOMEM;
 255                goto err_free_mem;
 256        }
 257
 258        keypad->irq = irq;
 259        keypad->board = plat;
 260        keypad->input = input;
 261        spin_lock_init(&keypad->ske_keypad_lock);
 262
 263        if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
 264                dev_err(&pdev->dev, "failed to request I/O memory\n");
 265                error = -EBUSY;
 266                goto err_free_mem;
 267        }
 268
 269        keypad->reg_base = ioremap(res->start, resource_size(res));
 270        if (!keypad->reg_base) {
 271                dev_err(&pdev->dev, "failed to remap I/O memory\n");
 272                error = -ENXIO;
 273                goto err_free_mem_region;
 274        }
 275
 276        keypad->pclk = clk_get(&pdev->dev, "apb_pclk");
 277        if (IS_ERR(keypad->pclk)) {
 278                dev_err(&pdev->dev, "failed to get pclk\n");
 279                error = PTR_ERR(keypad->pclk);
 280                goto err_iounmap;
 281        }
 282
 283        keypad->clk = clk_get(&pdev->dev, NULL);
 284        if (IS_ERR(keypad->clk)) {
 285                dev_err(&pdev->dev, "failed to get clk\n");
 286                error = PTR_ERR(keypad->clk);
 287                goto err_pclk;
 288        }
 289
 290        input->id.bustype = BUS_HOST;
 291        input->name = "ux500-ske-keypad";
 292        input->dev.parent = &pdev->dev;
 293
 294        error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
 295                                           SKE_KPD_NUM_ROWS, SKE_KPD_NUM_COLS,
 296                                           keypad->keymap, input);
 297        if (error) {
 298                dev_err(&pdev->dev, "Failed to build keymap\n");
 299                goto err_clk;
 300        }
 301
 302        input_set_capability(input, EV_MSC, MSC_SCAN);
 303        if (!plat->no_autorepeat)
 304                __set_bit(EV_REP, input->evbit);
 305
 306        error = clk_prepare_enable(keypad->pclk);
 307        if (error) {
 308                dev_err(&pdev->dev, "Failed to prepare/enable pclk\n");
 309                goto err_clk;
 310        }
 311
 312        error = clk_prepare_enable(keypad->clk);
 313        if (error) {
 314                dev_err(&pdev->dev, "Failed to prepare/enable clk\n");
 315                goto err_pclk_disable;
 316        }
 317
 318
 319        /* go through board initialization helpers */
 320        if (keypad->board->init)
 321                keypad->board->init();
 322
 323        error = ske_keypad_chip_init(keypad);
 324        if (error) {
 325                dev_err(&pdev->dev, "unable to init keypad hardware\n");
 326                goto err_clk_disable;
 327        }
 328
 329        error = request_threaded_irq(keypad->irq, NULL, ske_keypad_irq,
 330                                     IRQF_ONESHOT, "ske-keypad", keypad);
 331        if (error) {
 332                dev_err(&pdev->dev, "allocate irq %d failed\n", keypad->irq);
 333                goto err_clk_disable;
 334        }
 335
 336        error = input_register_device(input);
 337        if (error) {
 338                dev_err(&pdev->dev,
 339                                "unable to register input device: %d\n", error);
 340                goto err_free_irq;
 341        }
 342
 343        if (plat->wakeup_enable)
 344                device_init_wakeup(&pdev->dev, true);
 345
 346        platform_set_drvdata(pdev, keypad);
 347
 348        return 0;
 349
 350err_free_irq:
 351        free_irq(keypad->irq, keypad);
 352err_clk_disable:
 353        clk_disable_unprepare(keypad->clk);
 354err_pclk_disable:
 355        clk_disable_unprepare(keypad->pclk);
 356err_clk:
 357        clk_put(keypad->clk);
 358err_pclk:
 359        clk_put(keypad->pclk);
 360err_iounmap:
 361        iounmap(keypad->reg_base);
 362err_free_mem_region:
 363        release_mem_region(res->start, resource_size(res));
 364err_free_mem:
 365        input_free_device(input);
 366        kfree(keypad);
 367        return error;
 368}
 369
 370static int ske_keypad_remove(struct platform_device *pdev)
 371{
 372        struct ske_keypad *keypad = platform_get_drvdata(pdev);
 373        struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 374
 375        free_irq(keypad->irq, keypad);
 376
 377        input_unregister_device(keypad->input);
 378
 379        clk_disable_unprepare(keypad->clk);
 380        clk_put(keypad->clk);
 381
 382        if (keypad->board->exit)
 383                keypad->board->exit();
 384
 385        iounmap(keypad->reg_base);
 386        release_mem_region(res->start, resource_size(res));
 387        kfree(keypad);
 388
 389        return 0;
 390}
 391
 392#ifdef CONFIG_PM_SLEEP
 393static int ske_keypad_suspend(struct device *dev)
 394{
 395        struct platform_device *pdev = to_platform_device(dev);
 396        struct ske_keypad *keypad = platform_get_drvdata(pdev);
 397        int irq = platform_get_irq(pdev, 0);
 398
 399        if (device_may_wakeup(dev))
 400                enable_irq_wake(irq);
 401        else
 402                ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
 403
 404        return 0;
 405}
 406
 407static int ske_keypad_resume(struct device *dev)
 408{
 409        struct platform_device *pdev = to_platform_device(dev);
 410        struct ske_keypad *keypad = platform_get_drvdata(pdev);
 411        int irq = platform_get_irq(pdev, 0);
 412
 413        if (device_may_wakeup(dev))
 414                disable_irq_wake(irq);
 415        else
 416                ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
 417
 418        return 0;
 419}
 420#endif
 421
 422static SIMPLE_DEV_PM_OPS(ske_keypad_dev_pm_ops,
 423                         ske_keypad_suspend, ske_keypad_resume);
 424
 425static struct platform_driver ske_keypad_driver = {
 426        .driver = {
 427                .name = "nmk-ske-keypad",
 428                .pm = &ske_keypad_dev_pm_ops,
 429        },
 430        .remove = ske_keypad_remove,
 431};
 432
 433module_platform_driver_probe(ske_keypad_driver, ske_keypad_probe);
 434
 435MODULE_LICENSE("GPL v2");
 436MODULE_AUTHOR("Naveen Kumar <naveen.gaddipati@stericsson.com> / Sundar Iyer <sundar.iyer@stericsson.com>");
 437MODULE_DESCRIPTION("Nomadik Scroll-Key-Encoder Keypad Driver");
 438MODULE_ALIAS("platform:nomadik-ske-keypad");
 439