kernel/drivers/input/misc/bfin_rotary.c

   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
  29 struct 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
  46 static 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
  55 static 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
  68 static 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
  99 static 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
 120 static 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
 128 static void bfin_rotary_free_action(void *data)
 129 {
 130         peripheral_free_list(data);
 131 }
 132
 133 static 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(&pdev->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(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                         peripheral_free_list(pdata->pin_list);
 163                         return error;
 164                 }
 165         }
 166
 167         rotary = devm_kzalloc(dev, sizeof(struct bfin_rot), GFP_KERNEL);
 168         if (!rotary)
 169                 return -ENOMEM;
 170
 171         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 172         rotary->base = devm_ioremap_resource(dev, res);
 173         if (IS_ERR(rotary->base))
 174                 return PTR_ERR(rotary->base);
 175
 176         input = devm_input_allocate_device(dev);
 177         if (!input)
 178                 return -ENOMEM;
 179
 180         rotary->input = input;
 181
 182         rotary->up_key = pdata->rotary_up_key;
 183         rotary->down_key = pdata->rotary_down_key;
 184         rotary->button_key = pdata->rotary_button_key;
 185         rotary->rel_code = pdata->rotary_rel_code;
 186
 187         rotary->mode = pdata->mode;
 188         rotary->debounce = pdata->debounce;
 189
 190         input->name = pdev->name;
 191         input->phys = "bfin-rotary/input0";
 192         input->dev.parent = &pdev->dev;
 193
 194         input_set_drvdata(input, rotary);
 195
 196         input->id.bustype = BUS_HOST;
 197         input->id.vendor = 0x0001;
 198         input->id.product = 0x0001;
 199         input->id.version = 0x0100;
 200
 201         input->open = bfin_rotary_open;
 202         input->close = bfin_rotary_close;
 203
 204         if (rotary->up_key) {
 205                 __set_bit(EV_KEY, input->evbit);
 206                 __set_bit(rotary->up_key, input->keybit);
 207                 __set_bit(rotary->down_key, input->keybit);
 208         } else {
 209                 __set_bit(EV_REL, input->evbit);
 210                 __set_bit(rotary->rel_code, input->relbit);
 211         }
 212
 213         if (rotary->button_key) {
 214                 __set_bit(EV_KEY, input->evbit);
 215                 __set_bit(rotary->button_key, input->keybit);
 216         }
 217
 218         /* Quiesce the device before requesting irq */
 219         bfin_rotary_close(input);
 220
 221         rotary->irq = platform_get_irq(pdev, 0);
 222         if (rotary->irq < 0) {
 223                 dev_err(dev, "No rotary IRQ specified\n");
 224                 return -ENOENT;
 225         }
 226
 227         error = devm_request_irq(dev, rotary->irq, bfin_rotary_isr,
 228                                  0, dev_name(dev), rotary);
 229         if (error) {
 230                 dev_err(dev, "unable to claim irq %d; error %d\n",
 231                         rotary->irq, error);
 232                 return error;
 233         }
 234
 235         error = input_register_device(input);
 236         if (error) {
 237                 dev_err(dev, "unable to register input device (%d)\n", error);
 238                 return error;
 239         }
 240
 241         platform_set_drvdata(pdev, rotary);
 242         device_init_wakeup(&pdev->dev, 1);
 243
 244         return 0;
 245 }
 246
 247 static int __maybe_unused bfin_rotary_suspend(struct device *dev)
 248 {
 249         struct platform_device *pdev = to_platform_device(dev);
 250         struct bfin_rot *rotary = platform_get_drvdata(pdev);
 251
 252         rotary->cnt_config = readw(rotary->base + CNT_CONFIG_OFF);
 253         rotary->cnt_imask = readw(rotary->base + CNT_IMASK_OFF);
 254         rotary->cnt_debounce = readw(rotary->base + CNT_DEBOUNCE_OFF);
 255
 256         if (device_may_wakeup(&pdev->dev))
 257                 enable_irq_wake(rotary->irq);
 258
 259         return 0;
 260 }
 261
 262 static int __maybe_unused bfin_rotary_resume(struct device *dev)
 263 {
 264         struct platform_device *pdev = to_platform_device(dev);
 265         struct bfin_rot *rotary = platform_get_drvdata(pdev);
 266
 267         writew(rotary->cnt_debounce, rotary->base + CNT_DEBOUNCE_OFF);
 268         writew(rotary->cnt_imask, rotary->base + CNT_IMASK_OFF);
 269         writew(rotary->cnt_config & ~CNTE, rotary->base + CNT_CONFIG_OFF);
 270
 271         if (device_may_wakeup(&pdev->dev))
 272                 disable_irq_wake(rotary->irq);
 273
 274         if (rotary->cnt_config & CNTE)
 275                 writew(rotary->cnt_config, rotary->base + CNT_CONFIG_OFF);
 276
 277         return 0;
 278 }
 279
 280 static SIMPLE_DEV_PM_OPS(bfin_rotary_pm_ops,
 281                          bfin_rotary_suspend, bfin_rotary_resume);
 282
 283 static struct platform_driver bfin_rotary_device_driver = {
 284         .probe          = bfin_rotary_probe,
 285         .driver         = {
 286                 .name   = "bfin-rotary",
 287                 .pm     = &bfin_rotary_pm_ops,
 288         },
 289 };
 290 module_platform_driver(bfin_rotary_device_driver);
 291
 292 MODULE_LICENSE("GPL");
 293 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 294 MODULE_DESCRIPTION("Rotary Counter driver for Blackfin Processors");
 295 MODULE_ALIAS("platform:bfin-rotary");