linux/drivers/input/misc/bfin_rotary.c
<<
>>
Prefs
   1/*
   2 * Rotary counter driver for Analog Devices Blackfin Processors
   3 *
   4 * Copyright 2008-2009 Analog Devices Inc.
   5 * Licensed under the GPL-2 or later.
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/interrupt.h>
  10#include <linux/io.h>
  11#include <linux/irq.h>
  12#include <linux/pm.h>
  13#include <linux/platform_device.h>
  14#include <linux/input.h>
  15#include <linux/slab.h>
  16#include <linux/platform_data/bfin_rotary.h>
  17
  18#include <asm/portmux.h>
  19
  20#define CNT_CONFIG_OFF          0       /* CNT Config Offset */
  21#define CNT_IMASK_OFF           4       /* CNT Interrupt Mask Offset */
  22#define CNT_STATUS_OFF          8       /* CNT Status Offset */
  23#define CNT_COMMAND_OFF         12      /* CNT Command Offset */
  24#define CNT_DEBOUNCE_OFF        16      /* CNT Debounce Offset */
  25#define CNT_COUNTER_OFF         20      /* CNT Counter Offset */
  26#define CNT_MAX_OFF             24      /* CNT Maximum Count Offset */
  27#define CNT_MIN_OFF             28      /* CNT Minimum Count Offset */
  28
  29struct bfin_rot {
  30        struct input_dev *input;
  31        void __iomem *base;
  32        int irq;
  33        unsigned int up_key;
  34        unsigned int down_key;
  35        unsigned int button_key;
  36        unsigned int rel_code;
  37
  38        unsigned short mode;
  39        unsigned short debounce;
  40
  41        unsigned short cnt_config;
  42        unsigned short cnt_imask;
  43        unsigned short cnt_debounce;
  44};
  45
  46static void report_key_event(struct input_dev *input, int keycode)
  47{
  48        /* simulate a press-n-release */
  49        input_report_key(input, keycode, 1);
  50        input_sync(input);
  51        input_report_key(input, keycode, 0);
  52        input_sync(input);
  53}
  54
  55static void report_rotary_event(struct bfin_rot *rotary, int delta)
  56{
  57        struct input_dev *input = rotary->input;
  58
  59        if (rotary->up_key) {
  60                report_key_event(input,
  61                                 delta > 0 ? rotary->up_key : rotary->down_key);
  62        } else {
  63                input_report_rel(input, rotary->rel_code, delta);
  64                input_sync(input);
  65        }
  66}
  67
  68static irqreturn_t bfin_rotary_isr(int irq, void *dev_id)
  69{
  70        struct bfin_rot *rotary = dev_id;
  71        int delta;
  72
  73        switch (readw(rotary->base + CNT_STATUS_OFF)) {
  74
  75        case ICII:
  76                break;
  77
  78        case UCII:
  79        case DCII:
  80                delta = readl(rotary->base + CNT_COUNTER_OFF);
  81                if (delta)
  82                        report_rotary_event(rotary, delta);
  83                break;
  84
  85        case CZMII:
  86                report_key_event(rotary->input, rotary->button_key);
  87                break;
  88
  89        default:
  90                break;
  91        }
  92
  93        writew(W1LCNT_ZERO, rotary->base + CNT_COMMAND_OFF); /* Clear COUNTER */
  94        writew(-1, rotary->base + CNT_STATUS_OFF); /* Clear STATUS */
  95
  96        return IRQ_HANDLED;
  97}
  98
  99static int bfin_rotary_open(struct input_dev *input)
 100{
 101        struct bfin_rot *rotary = input_get_drvdata(input);
 102        unsigned short val;
 103
 104        if (rotary->mode & ROT_DEBE)
 105                writew(rotary->debounce & DPRESCALE,
 106                        rotary->base + CNT_DEBOUNCE_OFF);
 107
 108        writew(rotary->mode & ~CNTE, rotary->base + CNT_CONFIG_OFF);
 109
 110        val = UCIE | DCIE;
 111        if (rotary->button_key)
 112                val |= CZMIE;
 113        writew(val, rotary->base + CNT_IMASK_OFF);
 114
 115        writew(rotary->mode | CNTE, rotary->base + CNT_CONFIG_OFF);
 116
 117        return 0;
 118}
 119
 120static void bfin_rotary_close(struct input_dev *input)
 121{
 122        struct bfin_rot *rotary = input_get_drvdata(input);
 123
 124        writew(0, rotary->base + CNT_CONFIG_OFF);
 125        writew(0, rotary->base + CNT_IMASK_OFF);
 126}
 127
 128static void bfin_rotary_free_action(void *data)
 129{
 130        peripheral_free_list(data);
 131}
 132
 133static int bfin_rotary_probe(struct platform_device *pdev)
 134{
 135        struct device *dev = &pdev->dev;
 136        const struct bfin_rotary_platform_data *pdata = dev_get_platdata(dev);
 137        struct bfin_rot *rotary;
 138        struct resource *res;
 139        struct input_dev *input;
 140        int error;
 141
 142        /* Basic validation */
 143        if ((pdata->rotary_up_key && !pdata->rotary_down_key) ||
 144            (!pdata->rotary_up_key && pdata->rotary_down_key)) {
 145                return -EINVAL;
 146        }
 147
 148        if (pdata->pin_list) {
 149                error = peripheral_request_list(pdata->pin_list,
 150                                                dev_name(dev));
 151                if (error) {
 152                        dev_err(dev, "requesting peripherals failed: %d\n",
 153                                error);
 154                        return error;
 155                }
 156
 157                error = devm_add_action_or_reset(dev, bfin_rotary_free_action,
 158                                                 pdata->pin_list);
 159                if (error) {
 160                        dev_err(dev, "setting cleanup action failed: %d\n",
 161                                error);
 162                        return error;
 163                }
 164        }
 165
 166        rotary = devm_kzalloc(dev, sizeof(struct bfin_rot), GFP_KERNEL);
 167        if (!rotary)
 168                return -ENOMEM;
 169
 170        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 171        rotary->base = devm_ioremap_resource(dev, res);
 172        if (IS_ERR(rotary->base))
 173                return PTR_ERR(rotary->base);
 174
 175        input = devm_input_allocate_device(dev);
 176        if (!input)
 177                return -ENOMEM;
 178
 179        rotary->input = input;
 180
 181        rotary->up_key = pdata->rotary_up_key;
 182        rotary->down_key = pdata->rotary_down_key;
 183        rotary->button_key = pdata->rotary_button_key;
 184        rotary->rel_code = pdata->rotary_rel_code;
 185
 186        rotary->mode = pdata->mode;
 187        rotary->debounce = pdata->debounce;
 188
 189        input->name = pdev->name;
 190        input->phys = "bfin-rotary/input0";
 191        input->dev.parent = dev;
 192
 193        input_set_drvdata(input, rotary);
 194
 195        input->id.bustype = BUS_HOST;
 196        input->id.vendor = 0x0001;
 197        input->id.product = 0x0001;
 198        input->id.version = 0x0100;
 199
 200        input->open = bfin_rotary_open;
 201        input->close = bfin_rotary_close;
 202
 203        if (rotary->up_key) {
 204                __set_bit(EV_KEY, input->evbit);
 205                __set_bit(rotary->up_key, input->keybit);
 206                __set_bit(rotary->down_key, input->keybit);
 207        } else {
 208                __set_bit(EV_REL, input->evbit);
 209                __set_bit(rotary->rel_code, input->relbit);
 210        }
 211
 212        if (rotary->button_key) {
 213                __set_bit(EV_KEY, input->evbit);
 214                __set_bit(rotary->button_key, input->keybit);
 215        }
 216
 217        /* Quiesce the device before requesting irq */
 218        bfin_rotary_close(input);
 219
 220        rotary->irq = platform_get_irq(pdev, 0);
 221        if (rotary->irq < 0) {
 222                dev_err(dev, "No rotary IRQ specified\n");
 223                return -ENOENT;
 224        }
 225
 226        error = devm_request_irq(dev, rotary->irq, bfin_rotary_isr,
 227                                 0, dev_name(dev), rotary);
 228        if (error) {
 229                dev_err(dev, "unable to claim irq %d; error %d\n",
 230                        rotary->irq, error);
 231                return error;
 232        }
 233
 234        error = input_register_device(input);
 235        if (error) {
 236                dev_err(dev, "unable to register input device (%d)\n", error);
 237                return error;
 238        }
 239
 240        platform_set_drvdata(pdev, rotary);
 241        device_init_wakeup(dev, 1);
 242
 243        return 0;
 244}
 245
 246static int __maybe_unused bfin_rotary_suspend(struct device *dev)
 247{
 248        struct platform_device *pdev = to_platform_device(dev);
 249        struct bfin_rot *rotary = platform_get_drvdata(pdev);
 250
 251        rotary->cnt_config = readw(rotary->base + CNT_CONFIG_OFF);
 252        rotary->cnt_imask = readw(rotary->base + CNT_IMASK_OFF);
 253        rotary->cnt_debounce = readw(rotary->base + CNT_DEBOUNCE_OFF);
 254
 255        if (device_may_wakeup(&pdev->dev))
 256                enable_irq_wake(rotary->irq);
 257
 258        return 0;
 259}
 260
 261static int __maybe_unused bfin_rotary_resume(struct device *dev)
 262{
 263        struct platform_device *pdev = to_platform_device(dev);
 264        struct bfin_rot *rotary = platform_get_drvdata(pdev);
 265
 266        writew(rotary->cnt_debounce, rotary->base + CNT_DEBOUNCE_OFF);
 267        writew(rotary->cnt_imask, rotary->base + CNT_IMASK_OFF);
 268        writew(rotary->cnt_config & ~CNTE, rotary->base + CNT_CONFIG_OFF);
 269
 270        if (device_may_wakeup(&pdev->dev))
 271                disable_irq_wake(rotary->irq);
 272
 273        if (rotary->cnt_config & CNTE)
 274                writew(rotary->cnt_config, rotary->base + CNT_CONFIG_OFF);
 275
 276        return 0;
 277}
 278
 279static SIMPLE_DEV_PM_OPS(bfin_rotary_pm_ops,
 280                         bfin_rotary_suspend, bfin_rotary_resume);
 281
 282static struct platform_driver bfin_rotary_device_driver = {
 283        .probe          = bfin_rotary_probe,
 284        .driver         = {
 285                .name   = "bfin-rotary",
 286                .pm     = &bfin_rotary_pm_ops,
 287        },
 288};
 289module_platform_driver(bfin_rotary_device_driver);
 290
 291MODULE_LICENSE("GPL");
 292MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 293MODULE_DESCRIPTION("Rotary Counter driver for Blackfin Processors");
 294MODULE_ALIAS("platform:bfin-rotary");
 295