drivers/input/touchscreen/atmel-wm97xx.c

   1 /*
   2  * Atmel AT91 and AVR32 continuous touch screen driver for Wolfson WM97xx AC97
   3  * codecs.
   4  *
   5  * Copyright (C) 2008 - 2009 Atmel Corporation
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  */
  11 #include <linux/module.h>
  12 #include <linux/moduleparam.h>
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/delay.h>
  16 #include <linux/irq.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/wm97xx.h>
  19 #include <linux/timer.h>
  20 #include <linux/gpio.h>
  21 #include <linux/io.h>
  22 #include <linux/slab.h>
  23
  24 #define AC97C_ICA               0x10
  25 #define AC97C_CBRHR             0x30
  26 #define AC97C_CBSR              0x38
  27 #define AC97C_CBMR              0x3c
  28 #define AC97C_IER               0x54
  29 #define AC97C_IDR               0x58
  30
  31 #define AC97C_RXRDY             (1 << 4)
  32 #define AC97C_OVRUN             (1 << 5)
  33
  34 #define AC97C_CMR_SIZE_20       (0 << 16)
  35 #define AC97C_CMR_SIZE_18       (1 << 16)
  36 #define AC97C_CMR_SIZE_16       (2 << 16)
  37 #define AC97C_CMR_SIZE_10       (3 << 16)
  38 #define AC97C_CMR_CEM_LITTLE    (1 << 18)
  39 #define AC97C_CMR_CEM_BIG       (0 << 18)
  40 #define AC97C_CMR_CENA          (1 << 21)
  41
  42 #define AC97C_INT_CBEVT         (1 << 4)
  43
  44 #define AC97C_SR_CAEVT          (1 << 3)
  45
  46 #define AC97C_CH_MASK(slot)                                             \
  47         (0x7 << (3 * (slot - 3)))
  48 #define AC97C_CH_ASSIGN(slot, channel)                                  \
  49         (AC97C_CHANNEL_##channel << (3 * (slot - 3)))
  50 #define AC97C_CHANNEL_NONE      0x0
  51 #define AC97C_CHANNEL_B         0x2
  52
  53 #define ac97c_writel(chip, reg, val)                    \
  54         __raw_writel((val), (chip)->regs + AC97C_##reg)
  55 #define ac97c_readl(chip, reg)                          \
  56         __raw_readl((chip)->regs + AC97C_##reg)
  57
  58 #ifdef CONFIG_CPU_AT32AP700X
  59 #define ATMEL_WM97XX_AC97C_IOMEM        (0xfff02800)
  60 #define ATMEL_WM97XX_AC97C_IRQ          (29)
  61 #define ATMEL_WM97XX_GPIO_DEFAULT       (32+16) /* Pin 16 on port B. */
  62 #else
  63 #error Unknown CPU, this driver only supports AT32AP700X CPUs.
  64 #endif
  65
  66 struct continuous {
  67         u16 id;    /* codec id */
  68         u8 code;   /* continuous code */
  69         u8 reads;  /* number of coord reads per read cycle */
  70         u32 speed; /* number of coords per second */
  71 };
  72
  73 #define WM_READS(sp) ((sp / HZ) + 1)
  74
  75 static const struct continuous cinfo[] = {
  76         {WM9705_ID2, 0, WM_READS(94), 94},
  77         {WM9705_ID2, 1, WM_READS(188), 188},
  78         {WM9705_ID2, 2, WM_READS(375), 375},
  79         {WM9705_ID2, 3, WM_READS(750), 750},
  80         {WM9712_ID2, 0, WM_READS(94), 94},
  81         {WM9712_ID2, 1, WM_READS(188), 188},
  82         {WM9712_ID2, 2, WM_READS(375), 375},
  83         {WM9712_ID2, 3, WM_READS(750), 750},
  84         {WM9713_ID2, 0, WM_READS(94), 94},
  85         {WM9713_ID2, 1, WM_READS(120), 120},
  86         {WM9713_ID2, 2, WM_READS(154), 154},
  87         {WM9713_ID2, 3, WM_READS(188), 188},
  88 };
  89
  90 /* Continuous speed index. */
  91 static int sp_idx;
  92
  93 /*
  94  * Pen sampling frequency (Hz) in continuous mode.
  95  */
  96 static int cont_rate = 188;
  97 module_param(cont_rate, int, 0);
  98 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
  99
 100 /*
 101  * Pen down detection.
 102  *
 103  * This driver can either poll or use an interrupt to indicate a pen down
 104  * event. If the irq request fails then it will fall back to polling mode.
 105  */
 106 static int pen_int = 1;
 107 module_param(pen_int, int, 0);
 108 MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
 109
 110 /*
 111  * Pressure readback.
 112  *
 113  * Set to 1 to read back pen down pressure.
 114  */
 115 static int pressure;
 116 module_param(pressure, int, 0);
 117 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
 118
 119 /*
 120  * AC97 touch data slot.
 121  *
 122  * Touch screen readback data ac97 slot.
 123  */
 124 static int ac97_touch_slot = 5;
 125 module_param(ac97_touch_slot, int, 0);
 126 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
 127
 128 /*
 129  * GPIO line number.
 130  *
 131  * Set to GPIO number where the signal from the WM97xx device is hooked up.
 132  */
 133 static int atmel_gpio_line = ATMEL_WM97XX_GPIO_DEFAULT;
 134 module_param(atmel_gpio_line, int, 0);
 135 MODULE_PARM_DESC(atmel_gpio_line, "GPIO line number connected to WM97xx");
 136
 137 struct atmel_wm97xx {
 138         struct wm97xx           *wm;
 139         struct timer_list       pen_timer;
 140         void __iomem            *regs;
 141         unsigned long           ac97c_irq;
 142         unsigned long           gpio_pen;
 143         unsigned long           gpio_irq;
 144         unsigned short          x;
 145         unsigned short          y;
 146 };
 147
 148 static irqreturn_t atmel_wm97xx_channel_b_interrupt(int irq, void *dev_id)
 149 {
 150         struct atmel_wm97xx *atmel_wm97xx = dev_id;
 151         struct wm97xx *wm = atmel_wm97xx->wm;
 152         int status = ac97c_readl(atmel_wm97xx, CBSR);
 153         irqreturn_t retval = IRQ_NONE;
 154
 155         if (status & AC97C_OVRUN) {
 156                 dev_dbg(&wm->touch_dev->dev, "AC97C overrun\n");
 157                 ac97c_readl(atmel_wm97xx, CBRHR);
 158                 retval = IRQ_HANDLED;
 159         } else if (status & AC97C_RXRDY) {
 160                 u16 data;
 161                 u16 value;
 162                 u16 source;
 163                 u16 pen_down;
 164
 165                 data = ac97c_readl(atmel_wm97xx, CBRHR);
 166                 value = data & 0x0fff;
 167                 source = data & WM97XX_ADCSRC_MASK;
 168                 pen_down = (data & WM97XX_PEN_DOWN) >> 8;
 169
 170                 if (source == WM97XX_ADCSEL_X)
 171                         atmel_wm97xx->x = value;
 172                 if (source == WM97XX_ADCSEL_Y)
 173                         atmel_wm97xx->y = value;
 174
 175                 if (!pressure && source == WM97XX_ADCSEL_Y) {
 176                         input_report_abs(wm->input_dev, ABS_X, atmel_wm97xx->x);
 177                         input_report_abs(wm->input_dev, ABS_Y, atmel_wm97xx->y);
 178                         input_report_key(wm->input_dev, BTN_TOUCH, pen_down);
 179                         input_sync(wm->input_dev);
 180                 } else if (pressure && source == WM97XX_ADCSEL_PRES) {
 181                         input_report_abs(wm->input_dev, ABS_X, atmel_wm97xx->x);
 182                         input_report_abs(wm->input_dev, ABS_Y, atmel_wm97xx->y);
 183                         input_report_abs(wm->input_dev, ABS_PRESSURE, value);
 184                         input_report_key(wm->input_dev, BTN_TOUCH, value);
 185                         input_sync(wm->input_dev);
 186                 }
 187
 188                 retval = IRQ_HANDLED;
 189         }
 190
 191         return retval;
 192 }
 193
 194 static void atmel_wm97xx_acc_pen_up(struct wm97xx *wm)
 195 {
 196         struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(wm->touch_dev);
 197         struct input_dev *input_dev = wm->input_dev;
 198         int pen_down = gpio_get_value(atmel_wm97xx->gpio_pen);
 199
 200         if (pen_down != 0) {
 201                 mod_timer(&atmel_wm97xx->pen_timer,
 202                           jiffies + msecs_to_jiffies(1));
 203         } else {
 204                 if (pressure)
 205                         input_report_abs(input_dev, ABS_PRESSURE, 0);
 206                 input_report_key(input_dev, BTN_TOUCH, 0);
 207                 input_sync(input_dev);
 208         }
 209 }
 210
 211 static void atmel_wm97xx_pen_timer(unsigned long data)
 212 {
 213         atmel_wm97xx_acc_pen_up((struct wm97xx *)data);
 214 }
 215
 216 static int atmel_wm97xx_acc_startup(struct wm97xx *wm)
 217 {
 218         struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(wm->touch_dev);
 219         int idx = 0;
 220
 221         if (wm->ac97 == NULL)
 222                 return -ENODEV;
 223
 224         for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
 225                 if (wm->id != cinfo[idx].id)
 226                         continue;
 227
 228                 sp_idx = idx;
 229
 230                 if (cont_rate <= cinfo[idx].speed)
 231                         break;
 232         }
 233
 234         wm->acc_rate = cinfo[sp_idx].code;
 235         wm->acc_slot = ac97_touch_slot;
 236         dev_info(&wm->touch_dev->dev, "atmel accelerated touchscreen driver, "
 237                         "%d samples/sec\n", cinfo[sp_idx].speed);
 238
 239         if (pen_int) {
 240                 unsigned long reg;
 241
 242                 wm->pen_irq = atmel_wm97xx->gpio_irq;
 243
 244                 switch (wm->id) {
 245                 case WM9712_ID2: /* Fall through. */
 246                 case WM9713_ID2:
 247                         /*
 248                          * Use GPIO 13 (PEN_DOWN) to assert GPIO line 3
 249                          * (PENDOWN).
 250                          */
 251                         wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
 252                                         WM97XX_GPIO_POL_HIGH,
 253                                         WM97XX_GPIO_STICKY,
 254                                         WM97XX_GPIO_WAKE);
 255                         wm97xx_config_gpio(wm, WM97XX_GPIO_3, WM97XX_GPIO_OUT,
 256                                         WM97XX_GPIO_POL_HIGH,
 257                                         WM97XX_GPIO_NOTSTICKY,
 258                                         WM97XX_GPIO_NOWAKE);
 259                 case WM9705_ID2: /* Fall through. */
 260                         /*
 261                          * Enable touch data slot in AC97 controller channel B.
 262                          */
 263                         reg = ac97c_readl(atmel_wm97xx, ICA);
 264                         reg &= ~AC97C_CH_MASK(wm->acc_slot);
 265                         reg |= AC97C_CH_ASSIGN(wm->acc_slot, B);
 266                         ac97c_writel(atmel_wm97xx, ICA, reg);
 267
 268                         /*
 269                          * Enable channel and interrupt for RXRDY and OVERRUN.
 270                          */
 271                         ac97c_writel(atmel_wm97xx, CBMR, AC97C_CMR_CENA
 272                                         | AC97C_CMR_CEM_BIG
 273                                         | AC97C_CMR_SIZE_16
 274                                         | AC97C_OVRUN
 275                                         | AC97C_RXRDY);
 276                         /* Dummy read to empty RXRHR. */
 277                         ac97c_readl(atmel_wm97xx, CBRHR);
 278                         /*
 279                          * Enable interrupt for channel B in the AC97
 280                          * controller.
 281                          */
 282                         ac97c_writel(atmel_wm97xx, IER, AC97C_INT_CBEVT);
 283                         break;
 284                 default:
 285                         dev_err(&wm->touch_dev->dev, "pen down irq not "
 286                                         "supported on this device\n");
 287                         pen_int = 0;
 288                         break;
 289                 }
 290         }
 291
 292         return 0;
 293 }
 294
 295 static void atmel_wm97xx_acc_shutdown(struct wm97xx *wm)
 296 {
 297         if (pen_int) {
 298                 struct atmel_wm97xx *atmel_wm97xx =
 299                         platform_get_drvdata(wm->touch_dev);
 300                 unsigned long ica;
 301
 302                 switch (wm->id & 0xffff) {
 303                 case WM9705_ID2: /* Fall through. */
 304                 case WM9712_ID2: /* Fall through. */
 305                 case WM9713_ID2:
 306                         /* Disable slot and turn off channel B interrupts. */
 307                         ica = ac97c_readl(atmel_wm97xx, ICA);
 308                         ica &= ~AC97C_CH_MASK(wm->acc_slot);
 309                         ac97c_writel(atmel_wm97xx, ICA, ica);
 310                         ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
 311                         ac97c_writel(atmel_wm97xx, CBMR, 0);
 312                         wm->pen_irq = 0;
 313                         break;
 314                 default:
 315                         dev_err(&wm->touch_dev->dev, "unknown codec\n");
 316                         break;
 317                 }
 318         }
 319 }
 320
 321 static void atmel_wm97xx_irq_enable(struct wm97xx *wm, int enable)
 322 {
 323         /* Intentionally left empty. */
 324 }
 325
 326 static struct wm97xx_mach_ops atmel_mach_ops = {
 327         .acc_enabled    = 1,
 328         .acc_pen_up     = atmel_wm97xx_acc_pen_up,
 329         .acc_startup    = atmel_wm97xx_acc_startup,
 330         .acc_shutdown   = atmel_wm97xx_acc_shutdown,
 331         .irq_enable     = atmel_wm97xx_irq_enable,
 332         .irq_gpio       = WM97XX_GPIO_3,
 333 };
 334
 335 static int __init atmel_wm97xx_probe(struct platform_device *pdev)
 336 {
 337         struct wm97xx *wm = platform_get_drvdata(pdev);
 338         struct atmel_wm97xx *atmel_wm97xx;
 339         int ret;
 340
 341         atmel_wm97xx = kzalloc(sizeof(struct atmel_wm97xx), GFP_KERNEL);
 342         if (!atmel_wm97xx) {
 343                 dev_dbg(&pdev->dev, "out of memory\n");
 344                 return -ENOMEM;
 345         }
 346
 347         atmel_wm97xx->wm        = wm;
 348         atmel_wm97xx->regs      = (void *)ATMEL_WM97XX_AC97C_IOMEM;
 349         atmel_wm97xx->ac97c_irq = ATMEL_WM97XX_AC97C_IRQ;
 350         atmel_wm97xx->gpio_pen  = atmel_gpio_line;
 351         atmel_wm97xx->gpio_irq  = gpio_to_irq(atmel_wm97xx->gpio_pen);
 352
 353         setup_timer(&atmel_wm97xx->pen_timer, atmel_wm97xx_pen_timer,
 354                         (unsigned long)wm);
 355
 356         ret = request_irq(atmel_wm97xx->ac97c_irq,
 357                           atmel_wm97xx_channel_b_interrupt,
 358                           IRQF_SHARED, "atmel-wm97xx-ch-b", atmel_wm97xx);
 359         if (ret) {
 360                 dev_dbg(&pdev->dev, "could not request ac97c irq\n");
 361                 goto err;
 362         }
 363
 364         platform_set_drvdata(pdev, atmel_wm97xx);
 365
 366         ret = wm97xx_register_mach_ops(wm, &atmel_mach_ops);
 367         if (ret)
 368                 goto err_irq;
 369
 370         return ret;
 371
 372 err_irq:
 373         free_irq(atmel_wm97xx->ac97c_irq, atmel_wm97xx);
 374 err:
 375         platform_set_drvdata(pdev, NULL);
 376         kfree(atmel_wm97xx);
 377         return ret;
 378 }
 379
 380 static int __exit atmel_wm97xx_remove(struct platform_device *pdev)
 381 {
 382         struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
 383         struct wm97xx *wm = atmel_wm97xx->wm;
 384
 385         ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
 386         free_irq(atmel_wm97xx->ac97c_irq, atmel_wm97xx);
 387         del_timer_sync(&atmel_wm97xx->pen_timer);
 388         wm97xx_unregister_mach_ops(wm);
 389         platform_set_drvdata(pdev, NULL);
 390         kfree(atmel_wm97xx);
 391
 392         return 0;
 393 }
 394
 395 #ifdef CONFIG_PM
 396 static int atmel_wm97xx_suspend(struct platform_device *pdev, pm_message_t msg)
 397 {
 398         struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
 399
 400         ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
 401         disable_irq(atmel_wm97xx->gpio_irq);
 402         del_timer_sync(&atmel_wm97xx->pen_timer);
 403
 404         return 0;
 405 }
 406
 407 static int atmel_wm97xx_resume(struct platform_device *pdev)
 408 {
 409         struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
 410         struct wm97xx *wm = atmel_wm97xx->wm;
 411
 412         if (wm->input_dev->users) {
 413                 enable_irq(atmel_wm97xx->gpio_irq);
 414                 ac97c_writel(atmel_wm97xx, IER, AC97C_INT_CBEVT);
 415         }
 416
 417         return 0;
 418 }
 419 #else
 420 #define atmel_wm97xx_suspend    NULL
 421 #define atmel_wm97xx_resume     NULL
 422 #endif
 423
 424 static struct platform_driver atmel_wm97xx_driver = {
 425         .remove         = __exit_p(atmel_wm97xx_remove),
 426         .driver         = {
 427                 .name = "wm97xx-touch",
 428         },
 429         .suspend        = atmel_wm97xx_suspend,
 430         .resume         = atmel_wm97xx_resume,
 431 };
 432
 433 static int __init atmel_wm97xx_init(void)
 434 {
 435         return platform_driver_probe(&atmel_wm97xx_driver, atmel_wm97xx_probe);
 436 }
 437 module_init(atmel_wm97xx_init);
 438
 439 static void __exit atmel_wm97xx_exit(void)
 440 {
 441         platform_driver_unregister(&atmel_wm97xx_driver);
 442 }
 443 module_exit(atmel_wm97xx_exit);
 444
 445 MODULE_AUTHOR("Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>");
 446 MODULE_DESCRIPTION("wm97xx continuous touch driver for Atmel AT91 and AVR32");
 447 MODULE_LICENSE("GPL");