drivers/input/touchscreen/xpt2046_ts.c

   1 /*
   2  * drivers/input/touchscreen/xpt2046_ts.c - driver for rk2818 spi xpt2046 device and console
   3  *
   4  * Copyright (C) 2010 ROCKCHIP, Inc.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/hwmon.h>
  17 #include <linux/init.h>
  18 #include <linux/err.h>
  19 #include <linux/delay.h>
  20 #include <linux/input.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/slab.h>
  23 #include <linux/gpio.h>
  24 #include <linux/spi/spi.h>
  25 #include <asm/irq.h>
  26
  27 #include "xpt2046_ts.h"
  28
  29 /*
  30  * This code has been heavily tested on a Nokia 770, and lightly
  31  * tested on other xpt2046 devices (OSK/Mistral, Lubbock).
  32  * TSC2046 is just newer xpt2046 silicon.
  33  * Support for ads7843 tested on Atmel at91sam926x-EK.
  34  * Support for ads7845 has only been stubbed in.
  35  *
  36  * IRQ handling needs a workaround because of a shortcoming in handling
  37  * edge triggered IRQs on some platforms like the OMAP1/2. These
  38  * platforms don't handle the ARM lazy IRQ disabling properly, thus we
  39  * have to maintain our own SW IRQ disabled status. This should be
  40  * removed as soon as the affected platform's IRQ handling is fixed.
  41  *
  42  * app note sbaa036 talks in more detail about accurate sampling...
  43  * that ought to help in situations like LCDs inducing noise (which
  44  * can also be helped by using synch signals) and more generally.
  45  * This driver tries to utilize the measures described in the app
  46  * note. The strength of filtering can be set in the board-* specific
  47  * files.
  48  */
  49 #define XPT2046_DEBUG                   0
  50 #if XPT2046_DEBUG
  51         #define xpt2046printk(msg...)   printk(msg);
  52 #else
  53         #define xpt2046printk(msg...)
  54 #endif
  55 #define LCD_MAX_LENGTH                          800
  56 #define LCD_MAX_WIDTH                           480
  57 #define PT2046_TOUCH_AD_LEFT            3855
  58 #define PT2046_TOUCH_AD_RIGHT           260
  59 #define PT2046_TOUCH_AD_TOP             300
  60 #define PT2046_TOUCH_AD_BOTTOM  3755
  61 #define AD_TO_X(adx)    (LCD_MAX_WIDTH * (adx - PT2046_TOUCH_AD_TOP) / ( PT2046_TOUCH_AD_BOTTOM  - PT2046_TOUCH_AD_TOP ))
  62 #define AD_TO_Y(ady)    (LCD_MAX_LENGTH * (PT2046_TOUCH_AD_LEFT - ady) / (PT2046_TOUCH_AD_LEFT - PT2046_TOUCH_AD_RIGHT))
  63
  64 #define TS_POLL_DELAY   (10 * 1000000)  /* ns delay before the first sample */
  65 #define TS_POLL_PERIOD  (20 * 1000000)  /* ns delay between samples */
  66
  67 #define DEBOUNCE_REPTIME  3
  68 /* this driver doesn't aim at the peak continuous sample rate */
  69 #define SAMPLE_BITS     (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
  70
  71 struct ts_event {
  72         /* For portability, we can't read 12 bit values using SPI (which
  73          * would make the controller deliver them as native byteorder u16
  74          * with msbs zeroed).  Instead, we read them as two 8-bit values,
  75          * *** WHICH NEED BYTESWAPPING *** and range adjustment.
  76          */
  77         u16     x;
  78         u16     y;
  79         int     ignore;
  80 };
  81
  82 /*
  83  * We allocate this separately to avoid cache line sharing issues when
  84  * driver is used with DMA-based SPI controllers (like atmel_spi) on
  85  * systems where main memory is not DMA-coherent (most non-x86 boards).
  86  */
  87 struct xpt2046_packet {
  88         u8                      read_x, read_y, pwrdown;
  89         u16                     dummy;          /* for the pwrdown read */
  90         struct ts_event         tc;
  91 };
  92
  93 struct xpt2046 {
  94         struct input_dev        *input;
  95         char                    phys[32];
  96         char                    name[32];
  97
  98         struct spi_device       *spi;
  99
 100         u16                     model;
 101         bool                    swap_xy;
 102
 103         struct xpt2046_packet   *packet;
 104
 105         struct spi_transfer     xfer[18];
 106         struct spi_message      msg[5];
 107         struct spi_message      *last_msg;
 108         int                     msg_idx;
 109         int                     read_cnt;
 110         int                     read_rep;
 111         int                     last_read;
 112
 113         u16                     debounce_max;
 114         u16                     debounce_tol;
 115         u16                     debounce_rep;
 116
 117         u16                     penirq_recheck_delay_usecs;
 118
 119         spinlock_t              lock;
 120         struct hrtimer          timer;
 121         unsigned                pendown:1;      /* P: lock */
 122         unsigned                pending:1;      /* P: lock */
 123 // FIXME remove "irq_disabled"
 124         unsigned                irq_disabled:1; /* P: lock */
 125         unsigned                disabled:1;
 126         unsigned                is_suspended:1;
 127
 128         int                     (*filter)(void *data, int data_idx, int *val);
 129         void                    *filter_data;
 130         void                    (*filter_cleanup)(void *data);
 131         int                     (*get_pendown_state)(void);
 132         int                     gpio_pendown;
 133
 134         void                    (*wait_for_sync)(void);
 135 };
 136
 137 /* leave chip selected when we're done, for quicker re-select? */
 138 #if     0
 139 #define CS_CHANGE(xfer) ((xfer).cs_change = 1)
 140 #else
 141 #define CS_CHANGE(xfer) ((xfer).cs_change = 0)
 142 #endif
 143
 144 /*--------------------------------------------------------------------------*/
 145
 146 /* The xpt2046 has touchscreen and other sensors.
 147  * Earlier xpt2046 chips are somewhat compatible.
 148  */
 149 #define XPT2046_START                   (1 << 7)
 150 #define XPT2046_A2A1A0_d_y              (1 << 4)        /* differential */
 151 #define XPT2046_A2A1A0_d_z1             (3 << 4)        /* differential */
 152 #define XPT2046_A2A1A0_d_z2             (4 << 4)        /* differential */
 153 #define XPT2046_A2A1A0_d_x              (5 << 4)        /* differential */
 154 #define XPT2046_A2A1A0_temp0    (0 << 4)        /* non-differential */
 155 #define XPT2046_A2A1A0_vbatt    (2 << 4)        /* non-differential */
 156 #define XPT2046_A2A1A0_vaux             (6 << 4)        /* non-differential */
 157 #define XPT2046_A2A1A0_temp1    (7 << 4)        /* non-differential */
 158 #define XPT2046_8_BIT                   (1 << 3)
 159 #define XPT2046_12_BIT                  (0 << 3)
 160 #define XPT2046_SER                             (1 << 2)        /* non-differential */
 161 #define XPT2046_DFR                             (0 << 2)        /* differential */
 162 #define XPT2046_PD10_PDOWN              (0 << 0)        /* lowpower mode + penirq */
 163 #define XPT2046_PD10_ADC_ON             (1 << 0)        /* ADC on */
 164 #define XPT2046_PD10_REF_ON             (2 << 0)        /* vREF on + penirq */
 165 #define XPT2046_PD10_ALL_ON             (3 << 0)        /* ADC + vREF on */
 166
 167 #define MAX_12BIT       ((1<<12)-1)
 168
 169 /* leave ADC powered up (disables penirq) between differential samples */
 170 #define READ_12BIT_DFR(x, adc, vref) (XPT2046_START | XPT2046_A2A1A0_d_ ## x \
 171         | XPT2046_12_BIT | XPT2046_DFR | \
 172         (adc ? XPT2046_PD10_ADC_ON : 0) | (vref ? XPT2046_PD10_REF_ON : 0))
 173
 174 #define READ_Y(vref)    (READ_12BIT_DFR(y,  1, vref))
 175 #define READ_Z1(vref)   (READ_12BIT_DFR(z1, 1, vref))
 176 #define READ_Z2(vref)   (READ_12BIT_DFR(z2, 1, vref))
 177
 178 #define READ_X(vref)    (READ_12BIT_DFR(x,  1, vref))
 179 #define PWRDOWN         (READ_12BIT_DFR(y,  0, 0))      /* LAST */
 180
 181 /* single-ended samples need to first power up reference voltage;
 182  * we leave both ADC and VREF powered
 183  */
 184 #define READ_12BIT_SER(x) (XPT2046_START | XPT2046_A2A1A0_ ## x \
 185         | XPT2046_12_BIT | XPT2046_SER)
 186
 187 #define REF_ON  (READ_12BIT_DFR(x, 1, 1))
 188 #define REF_OFF (READ_12BIT_DFR(y, 0, 0))
 189
 190 /*--------------------------------------------------------------------------*/
 191 /*
 192  * touchscreen sensors  use differential conversions.
 193  */
 194
 195 struct dfr_req {
 196         u8                      command;
 197         u8                      pwrdown;
 198         u16                     dummy;          /* for the pwrdown read */
 199         __be16                  sample;
 200         struct spi_message      msg;
 201         struct spi_transfer     xfer[4];
 202 };
 203
 204 static void xpt2046_enable(struct xpt2046 *ts);
 205 static void xpt2046_disable(struct xpt2046 *ts);
 206
 207 static int device_suspended(struct device *dev)
 208 {
 209         struct xpt2046 *ts = dev_get_drvdata(dev);
 210         return ts->is_suspended || ts->disabled;
 211 }
 212
 213 static int xpt2046_read12_dfr(struct device *dev, unsigned command)
 214 {
 215         struct spi_device       *spi = to_spi_device(dev);
 216         struct xpt2046          *ts = dev_get_drvdata(dev);
 217         struct dfr_req          *req = kzalloc(sizeof *req, GFP_KERNEL);
 218         int                     status;
 219
 220         if (!req)
 221                 return -ENOMEM;
 222
 223         spi_message_init(&req->msg);
 224
 225         /* take sample */
 226         req->command = (u8) command;
 227         req->xfer[0].tx_buf = &req->command;
 228         req->xfer[0].len = 1;
 229         spi_message_add_tail(&req->xfer[0], &req->msg);
 230
 231         req->xfer[1].rx_buf = &req->sample;
 232         req->xfer[1].len = 2;
 233         spi_message_add_tail(&req->xfer[1], &req->msg);
 234
 235         /* converter in low power mode & enable PENIRQ */
 236         req->pwrdown= PWRDOWN;
 237         req->xfer[2].tx_buf = &req->pwrdown;
 238         req->xfer[2].len = 1;
 239         spi_message_add_tail(&req->xfer[2], &req->msg);
 240
 241         req->xfer[3].rx_buf = &req->dummy;
 242         req->xfer[3].len = 2;
 243         CS_CHANGE(req->xfer[3]);
 244         spi_message_add_tail(&req->xfer[3], &req->msg);
 245
 246         ts->irq_disabled = 1;
 247         disable_irq(spi->irq);
 248         status = spi_sync(spi, &req->msg);
 249         ts->irq_disabled = 0;
 250         enable_irq(spi->irq);
 251
 252         if (status == 0) {
 253                 /* on-wire is a must-ignore bit, a BE12 value, then padding */
 254                 status = be16_to_cpu(req->sample);
 255                 status = status >> 3;
 256                 status &= 0x0fff;
 257                 xpt2046printk("***>%s:status=%d\n",__FUNCTION__,status);
 258         }
 259
 260         kfree(req);
 261         return status;
 262 }
 263
 264
 265
 266 /*--------------------------------------------------------------------------*/
 267
 268 static int get_pendown_state(struct xpt2046 *ts)
 269 {
 270         if (ts->get_pendown_state)
 271                 return ts->get_pendown_state();
 272
 273         return !gpio_get_value(ts->gpio_pendown);
 274 }
 275
 276 static void null_wait_for_sync(void)
 277 {
 278
 279 }
 280
 281 /*
 282  * PENIRQ only kicks the timer.  The timer only reissues the SPI transfer,
 283  * to retrieve touchscreen status.
 284  *
 285  * The SPI transfer completion callback does the real work.  It reports
 286  * touchscreen events and reactivates the timer (or IRQ) as appropriate.
 287  */
 288
 289 static void xpt2046_rx(void *xpt)
 290 {
 291         struct xpt2046          *ts = xpt;
 292         struct xpt2046_packet   *packet = ts->packet;
 293         unsigned                Rt = 1;
 294         u16                     x, y;
 295
 296         /* xpt2046_rx_val() did in-place conversion (including byteswap) from
 297          * on-the-wire format as part of debouncing to get stable readings.
 298          */
 299         x = packet->tc.x;
 300         y = packet->tc.y;
 301
 302         xpt2046printk("***>%s:x=%d,y=%d\n",__FUNCTION__,x,y);
 303
 304         /* range filtering */
 305         if (x == MAX_12BIT)
 306                 x = 0;
 307
 308         /* Sample found inconsistent by debouncing or pressure is beyond
 309          * the maximum. Don't report it to user space, repeat at least
 310          * once more the measurement
 311          */
 312         if (packet->tc.ignore) {
 313
 314                 xpt2046printk("***>%s:ignored=%d\n",__FUNCTION__,packet->tc.ignore);
 315
 316                 hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
 317                               HRTIMER_MODE_REL);
 318                 return;
 319         }
 320
 321         /* Maybe check the pendown state before reporting. This discards
 322          * false readings when the pen is lifted.
 323          */
 324         if (ts->penirq_recheck_delay_usecs) {
 325                 udelay(ts->penirq_recheck_delay_usecs);
 326                 if (!get_pendown_state(ts))
 327                 {
 328                         xpt2046printk("***>%s:get_pendown_state(ts)==0,discard false reading\n",__FUNCTION__);
 329                         Rt = 0;
 330                 }
 331         }
 332
 333         /* NOTE: We can't rely on the pressure to determine the pen down
 334          * state, even this controller has a pressure sensor.  The pressure
 335          * value can fluctuate for quite a while after lifting the pen and
 336          * in some cases may not even settle at the expected value.
 337          *
 338          * The only safe way to check for the pen up condition is in the
 339          * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
 340          */
 341         if (Rt) {
 342                 struct input_dev *input = ts->input;
 343                 if (!ts->pendown) {
 344                         input_report_key(input, BTN_TOUCH, 1);
 345                         ts->pendown = 1;
 346                         xpt2046printk("***>%s:input_report_key(pen down)\n",__FUNCTION__);
 347                 }
 348
 349                 x =  AD_TO_X(x);
 350                 y =  AD_TO_Y(y);
 351
 352                 if (ts->swap_xy)
 353                         swap(x, y);
 354
 355                 input_report_abs(input, ABS_X, x);
 356                 input_report_abs(input, ABS_Y, y);
 357
 358                 input_sync(input);
 359                 xpt2046printk("***>%s:input_report_abs(%4d/%4d)\n",__FUNCTION__,x, y);
 360         }
 361
 362         hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
 363                         HRTIMER_MODE_REL);
 364 }
 365
 366 static int xpt2046_debounce(void *xpt, int data_idx, int *val)
 367 {
 368         struct xpt2046          *ts = xpt;
 369         static int average_val[2];
 370
 371
 372         xpt2046printk("***>%s:%d,%d,%d,%d,%d,%d,%d,%d\n",__FUNCTION__,
 373                 data_idx,ts->last_read,
 374           ts->read_cnt,ts->debounce_max,
 375                 abs(ts->last_read - *val),ts->debounce_tol,
 376                 ts->read_rep,ts->debounce_rep);
 377
 378         if(*val == 4095 || *val == 0)
 379         {
 380                 ts->read_cnt = 0;
 381                 ts->last_read = 0;
 382                 memset(average_val,0,sizeof(average_val));
 383                 xpt2046printk("***>%s:*val == 4095 || *val == 0\n",__FUNCTION__);
 384                 return XPT2046_FILTER_IGNORE;
 385         }
 386         /* discard the first sample. */
 387         if(!ts->read_cnt)
 388         {
 389                 ts->read_cnt++;
 390                 return XPT2046_FILTER_REPEAT;
 391         }
 392
 393         if (ts->read_cnt==1 || (abs(ts->last_read - *val) > ts->debounce_tol)) {
 394                 /* Start over collecting consistent readings. */
 395                 ts->read_rep = 1;
 396                 average_val[data_idx] = *val;
 397                 /* Repeat it, if this was the first read or the read
 398                  * wasn't consistent enough. */
 399                 if (ts->read_cnt < ts->debounce_max) {
 400                         ts->last_read = *val;
 401                         ts->read_cnt++;
 402                         return XPT2046_FILTER_REPEAT;
 403                 } else {
 404                         /* Maximum number of debouncing reached and still
 405                          * not enough number of consistent readings. Abort
 406                          * the whole sample, repeat it in the next sampling
 407                          * period.
 408                          */
 409                         ts->read_cnt = 0;
 410                         ts->last_read = 0;
 411                         memset(average_val,0,sizeof(average_val));
 412                         xpt2046printk("***>%s:XPT2046_FILTER_IGNORE\n",__FUNCTION__);
 413                         return XPT2046_FILTER_IGNORE;
 414                 }
 415         }
 416         else {
 417                 average_val[data_idx] += *val;
 418
 419                 if (++ts->read_rep >= ts->debounce_rep) {
 420                         /* Got a good reading for this coordinate,
 421                          * go for the next one. */
 422                         ts->read_cnt = 0;
 423                         ts->read_rep = 0;
 424                         ts->last_read = 0;
 425                         *val = average_val[data_idx]/(ts->debounce_rep);
 426                         return XPT2046_FILTER_OK;
 427                 } else {
 428                         /* Read more values that are consistent. */
 429                         ts->read_cnt++;
 430
 431                         return XPT2046_FILTER_REPEAT;
 432                 }
 433         }
 434 }
 435
 436 static int xpt2046_no_filter(void *xpt, int data_idx, int *val)
 437 {
 438         return XPT2046_FILTER_OK;
 439 }
 440
 441 static void xpt2046_rx_val(void *xpt)
 442 {
 443         struct xpt2046 *ts = xpt;
 444         struct xpt2046_packet *packet = ts->packet;
 445         struct spi_message *m;
 446         struct spi_transfer *t;
 447         int val;
 448         int action;
 449         int status;
 450
 451         m = &ts->msg[ts->msg_idx];
 452         t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 453
 454         /* adjust:  on-wire is a must-ignore bit, a BE12 value, then padding;
 455          * built from two 8 bit values written msb-first.
 456          */
 457         val = (be16_to_cpup((__be16 *)t->rx_buf) >> 3) & 0x0fff;
 458
 459         xpt2046printk("***>%s:value=%d\n",__FUNCTION__,val);
 460
 461         action = ts->filter(ts->filter_data, ts->msg_idx, &val);
 462         switch (action) {
 463         case XPT2046_FILTER_REPEAT:
 464                 break;
 465         case XPT2046_FILTER_IGNORE:
 466                 packet->tc.ignore = 1;
 467                 /* Last message will contain xpt2046_rx() as the
 468                  * completion function.
 469                  */
 470                 m = ts->last_msg;
 471                 break;
 472         case XPT2046_FILTER_OK:
 473                 *(u16 *)t->rx_buf = val;
 474                 packet->tc.ignore = 0;
 475                 m = &ts->msg[++ts->msg_idx];
 476                 break;
 477         default:
 478                 BUG();
 479         }
 480         ts->wait_for_sync();
 481         status = spi_async(ts->spi, m);
 482         if (status)
 483                 dev_err(&ts->spi->dev, "spi_async --> %d\n",
 484                                 status);
 485 }
 486
 487 static enum hrtimer_restart xpt2046_timer(struct hrtimer *handle)
 488 {
 489         struct xpt2046  *ts = container_of(handle, struct xpt2046, timer);
 490         int             status = 0;
 491
 492         spin_lock(&ts->lock);
 493
 494         if (unlikely(!get_pendown_state(ts) ||
 495                      device_suspended(&ts->spi->dev))) {
 496                 if (ts->pendown) {
 497                         struct input_dev *input = ts->input;
 498                         input_report_key(input, BTN_TOUCH, 0);
 499                         input_sync(input);
 500
 501                         ts->pendown = 0;
 502
 503                         xpt2046printk("***>%s:input_report_key(The touchscreen up)\n",__FUNCTION__);
 504                 }
 505
 506                 /* measurement cycle ended */
 507                 if (!device_suspended(&ts->spi->dev)) {
 508                         xpt2046printk("***>%s:device_suspended==0\n",__FUNCTION__);
 509                         ts->irq_disabled = 0;
 510                         enable_irq(ts->spi->irq);
 511                 }
 512                 ts->pending = 0;
 513         } else {
 514                 /* pen is still down, continue with the measurement */
 515                 xpt2046printk("***>%s:pen is still down, continue with the measurement\n",__FUNCTION__);
 516                 ts->msg_idx = 0;
 517                 ts->wait_for_sync();
 518                 status = spi_async(ts->spi, &ts->msg[0]);
 519                 if (status)
 520                         dev_err(&ts->spi->dev, "spi_async --> %d\n", status);
 521         }
 522
 523         spin_unlock(&ts->lock);
 524         return HRTIMER_NORESTART;
 525 }
 526
 527 static irqreturn_t xpt2046_irq(int irq, void *handle)
 528 {
 529         struct xpt2046 *ts = handle;
 530         unsigned long flags;
 531
 532         xpt2046printk("***>%s.....%s.....%d\n",__FILE__,__FUNCTION__,__LINE__);
 533
 534         spin_lock_irqsave(&ts->lock, flags);
 535
 536         if (likely(get_pendown_state(ts))) {
 537                 if (!ts->irq_disabled) {
 538                         /* The ARM do_simple_IRQ() dispatcher doesn't act
 539                          * like the other dispatchers:  it will report IRQs
 540                          * even after they've been disabled.  We work around
 541                          * that here.  (The "generic irq" framework may help...)
 542                          */
 543                         ts->irq_disabled = 1;
 544                         disable_irq_nosync(ts->spi->irq);
 545                         ts->pending = 1;
 546                         hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
 547                                         HRTIMER_MODE_REL);
 548                 }
 549         }
 550         spin_unlock_irqrestore(&ts->lock, flags);
 551
 552         return IRQ_HANDLED;
 553 }
 554
 555 /*--------------------------------------------------------------------------*/
 556
 557 /* Must be called with ts->lock held */
 558 static void xpt2046_disable(struct xpt2046 *ts)
 559 {
 560         if (ts->disabled)
 561                 return;
 562
 563         ts->disabled = 1;
 564
 565         /* are we waiting for IRQ, or polling? */
 566         if (!ts->pending) {
 567                 ts->irq_disabled = 1;
 568                 disable_irq(ts->spi->irq);
 569         } else {
 570                 /* the timer will run at least once more, and
 571                  * leave everything in a clean state, IRQ disabled
 572                  */
 573                 while (ts->pending) {
 574                         spin_unlock_irq(&ts->lock);
 575                         msleep(1);
 576                         spin_lock_irq(&ts->lock);
 577                 }
 578         }
 579
 580         /* we know the chip's in lowpower mode since we always
 581          * leave it that way after every request
 582          */
 583 }
 584
 585 /* Must be called with ts->lock held */
 586 static void xpt2046_enable(struct xpt2046 *ts)
 587 {
 588         if (!ts->disabled)
 589                 return;
 590
 591         ts->disabled = 0;
 592         ts->irq_disabled = 0;
 593         enable_irq(ts->spi->irq);
 594 }
 595
 596 static int xpt2046_suspend(struct spi_device *spi, pm_message_t message)
 597 {
 598         struct xpt2046 *ts = dev_get_drvdata(&spi->dev);
 599
 600         spin_lock_irq(&ts->lock);
 601
 602         ts->is_suspended = 1;
 603         xpt2046_disable(ts);
 604
 605         spin_unlock_irq(&ts->lock);
 606
 607         return 0;
 608
 609 }
 610
 611 static int xpt2046_resume(struct spi_device *spi)
 612 {
 613         struct xpt2046 *ts = dev_get_drvdata(&spi->dev);
 614
 615         spin_lock_irq(&ts->lock);
 616
 617         ts->is_suspended = 0;
 618         xpt2046_enable(ts);
 619
 620         spin_unlock_irq(&ts->lock);
 621
 622         return 0;
 623 }
 624
 625 static int __devinit setup_pendown(struct spi_device *spi, struct xpt2046 *ts)
 626 {
 627         struct xpt2046_platform_data *pdata = spi->dev.platform_data;
 628         int err;
 629
 630         /* REVISIT when the irq can be triggered active-low, or if for some
 631          * reason the touchscreen isn't hooked up, we don't need to access
 632          * the pendown state.
 633          */
 634         if (!pdata->get_pendown_state && !gpio_is_valid(pdata->gpio_pendown)) {
 635                 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
 636                 return -EINVAL;
 637         }
 638
 639         if (pdata->get_pendown_state) {
 640                 ts->get_pendown_state = pdata->get_pendown_state;
 641                 return 0;
 642         }
 643
 644     if (pdata->io_init) {
 645         err = pdata->io_init();
 646         if (err)
 647             dev_err(&spi->dev, "xpt2046 io_init fail\n");
 648     }
 649
 650         err = gpio_request(pdata->gpio_pendown, "xpt2046_pendown");
 651         if (err) {
 652                 dev_err(&spi->dev, "failed to request pendown GPIO%d\n",
 653                                 pdata->gpio_pendown);
 654                 return err;
 655         }
 656
 657         ts->gpio_pendown = pdata->gpio_pendown;
 658         return 0;
 659 }
 660
 661 static int __devinit xpt2046_probe(struct spi_device *spi)
 662 {
 663         struct xpt2046                  *ts;
 664         struct xpt2046_packet           *packet;
 665         struct input_dev                *input_dev;
 666         struct xpt2046_platform_data    *pdata = spi->dev.platform_data;
 667         struct spi_message              *m;
 668         struct spi_transfer             *x;
 669         int                             vref;
 670         int                             err;
 671
 672
 673
 674         if (!spi->irq) {
 675                 dev_dbg(&spi->dev, "no IRQ?\n");
 676                 return -ENODEV;
 677         }
 678         else{
 679                 spi->irq = gpio_to_irq(spi->irq);
 680                 dev_dbg(&spi->dev, "no IRQ?\n");
 681         }
 682
 683     if (!pdata) {
 684                 dev_err(&spi->dev, "empty platform_data\n");
 685                 return -EFAULT;
 686     }
 687
 688         /* don't exceed max specified sample rate */
 689         if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
 690                 dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
 691                                 (spi->max_speed_hz/SAMPLE_BITS)/1000);
 692                 return -EINVAL;
 693         }
 694
 695         /* We'd set TX wordsize 8 bits and RX wordsize to 13 bits ... except
 696          * that even if the hardware can do that, the SPI controller driver
 697          * may not.  So we stick to very-portable 8 bit words, both RX and TX.
 698          */
 699         spi->bits_per_word = 8;
 700         spi->mode = SPI_MODE_0;
 701         err = spi_setup(spi);
 702         if (err < 0)
 703                 return err;
 704
 705         ts = kzalloc(sizeof(struct xpt2046), GFP_KERNEL);
 706         packet = kzalloc(sizeof(struct xpt2046_packet), GFP_KERNEL);
 707         input_dev = input_allocate_device();
 708         if (!ts || !packet || !input_dev) {
 709                 err = -ENOMEM;
 710                 goto err_free_mem;
 711         }
 712
 713         dev_set_drvdata(&spi->dev, ts);
 714
 715         ts->packet = packet;
 716         ts->spi = spi;
 717         ts->input = input_dev;
 718         ts->swap_xy = pdata->swap_xy;
 719
 720         hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 721         ts->timer.function = xpt2046_timer;
 722
 723         spin_lock_init(&ts->lock);
 724
 725         ts->model = pdata->model ? : 2046;
 726
 727         if (pdata->filter != NULL) {
 728                 if (pdata->filter_init != NULL) {
 729                         err = pdata->filter_init(pdata, &ts->filter_data);
 730                         if (err < 0)
 731                                 goto err_free_mem;
 732                 }
 733                 ts->filter = pdata->filter;
 734                 ts->filter_cleanup = pdata->filter_cleanup;
 735         } else if (pdata->debounce_max) {
 736                 ts->debounce_max = pdata->debounce_max;
 737                 if (ts->debounce_max < pdata->debounce_rep)
 738                         ts->debounce_max = pdata->debounce_rep;
 739                 ts->debounce_tol = pdata->debounce_tol;
 740                 ts->debounce_rep = pdata->debounce_rep;
 741                 ts->filter = xpt2046_debounce;
 742                 ts->filter_data = ts;
 743         } else
 744                 ts->filter = xpt2046_no_filter;
 745
 746         err = setup_pendown(spi, ts);
 747         if (err)
 748                 goto err_cleanup_filter;
 749
 750         if (pdata->penirq_recheck_delay_usecs)
 751                 ts->penirq_recheck_delay_usecs =
 752                                 pdata->penirq_recheck_delay_usecs;
 753
 754         ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
 755
 756         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
 757         snprintf(ts->name, sizeof(ts->name), "XPT%d Touchscreen", ts->model);
 758
 759         input_dev->name = ts->name;
 760         input_dev->phys = ts->phys;
 761         input_dev->dev.parent = &spi->dev;
 762
 763         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 764         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 765         input_set_abs_params(input_dev, ABS_X,
 766                         pdata->x_min ? : 0,
 767                         pdata->x_max ? : MAX_12BIT,
 768                         0, 0);
 769         input_set_abs_params(input_dev, ABS_Y,
 770                         pdata->y_min ? : 0,
 771                         pdata->y_max ? : MAX_12BIT,
 772                         0, 0);
 773
 774         vref = pdata->keep_vref_on;
 775
 776         /* set up the transfers to read touchscreen state; this assumes we
 777          * use formula #2 for pressure, not #3.
 778          */
 779         m = &ts->msg[0];
 780         x = ts->xfer;
 781
 782         spi_message_init(m);
 783
 784         /* y- still on; turn on only y+ (and ADC) */
 785         packet->read_y = READ_Y(vref);
 786         x->tx_buf = &packet->read_y;
 787         x->len = 1;
 788         spi_message_add_tail(x, m);
 789
 790         x++;
 791         x->rx_buf = &packet->tc.y;
 792         x->len = 2;
 793         spi_message_add_tail(x, m);
 794
 795         m->complete = xpt2046_rx_val;
 796         m->context = ts;
 797
 798         m++;
 799         spi_message_init(m);
 800
 801         /* turn y- off, x+ on, then leave in lowpower */
 802         x++;
 803         packet->read_x = READ_X(vref);
 804         x->tx_buf = &packet->read_x;
 805         x->len = 1;
 806         spi_message_add_tail(x, m);
 807
 808         x++;
 809         x->rx_buf = &packet->tc.x;
 810         x->len = 2;
 811         spi_message_add_tail(x, m);
 812
 813         m->complete = xpt2046_rx_val;
 814         m->context = ts;
 815
 816         /* power down */
 817         m++;
 818         spi_message_init(m);
 819
 820         x++;
 821         packet->pwrdown = PWRDOWN;
 822         x->tx_buf = &packet->pwrdown;
 823         x->len = 1;
 824         spi_message_add_tail(x, m);
 825
 826         x++;
 827         x->rx_buf = &packet->dummy;
 828         x->len = 2;
 829         CS_CHANGE(*x);
 830         spi_message_add_tail(x, m);
 831
 832         m->complete = xpt2046_rx;
 833         m->context = ts;
 834
 835         ts->last_msg = m;
 836
 837         if (request_irq(spi->irq, xpt2046_irq, IRQF_TRIGGER_FALLING,
 838                         spi->dev.driver->name, ts)) {
 839                 printk("%s:trying pin change workaround on irq %d\n",__FUNCTION__,spi->irq);
 840                 err = request_irq(spi->irq, xpt2046_irq,
 841                                   IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
 842                                   spi->dev.driver->name, ts);
 843                 if (err) {
 844                         dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
 845                         goto err_free_gpio;
 846                 }
 847         }
 848         xpt2046printk("***>%s:touchscreen irq %d\n",__FUNCTION__,spi->irq);
 849
 850         /* take a first sample, leaving nPENIRQ active and vREF off; avoid
 851          * the touchscreen, in case it's not connected.
 852          */
 853         xpt2046_read12_dfr(&spi->dev,READ_X(1));
 854
 855         err = input_register_device(input_dev);
 856         if (err)
 857                 goto err_remove_attr_group;
 858   printk("xpt2046_ts: driver initialized\n");
 859         return 0;
 860
 861  err_remove_attr_group:
 862         free_irq(spi->irq, ts);
 863  err_free_gpio:
 864         if (ts->gpio_pendown != -1)
 865                 gpio_free(ts->gpio_pendown);
 866  err_cleanup_filter:
 867         if (ts->filter_cleanup)
 868                 ts->filter_cleanup(ts->filter_data);
 869  err_free_mem:
 870         input_free_device(input_dev);
 871         kfree(packet);
 872         kfree(ts);
 873         return err;
 874 }
 875
 876 static int __devexit xpt2046_remove(struct spi_device *spi)
 877 {
 878         struct xpt2046          *ts = dev_get_drvdata(&spi->dev);
 879
 880         input_unregister_device(ts->input);
 881
 882         xpt2046_suspend(spi, PMSG_SUSPEND);
 883
 884         free_irq(ts->spi->irq, ts);
 885         /* suspend left the IRQ disabled */
 886         enable_irq(ts->spi->irq);
 887
 888         if (ts->gpio_pendown != -1)
 889                 gpio_free(ts->gpio_pendown);
 890
 891         if (ts->filter_cleanup)
 892                 ts->filter_cleanup(ts->filter_data);
 893
 894         kfree(ts->packet);
 895         kfree(ts);
 896
 897         dev_dbg(&spi->dev, "unregistered touchscreen\n");
 898         return 0;
 899 }
 900
 901 static struct spi_driver xpt2046_driver = {
 902         .driver = {
 903                 .name   = "xpt2046_ts",
 904                 .bus    = &spi_bus_type,
 905                 .owner  = THIS_MODULE,
 906         },
 907         .probe          = xpt2046_probe,
 908         .remove         = __devexit_p(xpt2046_remove),
 909         .suspend        = xpt2046_suspend,
 910         .resume         = xpt2046_resume,
 911 };
 912
 913 static int __init xpt2046_init(void)
 914 {
 915         return spi_register_driver(&xpt2046_driver);
 916 }
 917 module_init(xpt2046_init);
 918
 919 static void __exit xpt2046_exit(void)
 920 {
 921         spi_unregister_driver(&xpt2046_driver);
 922 }
 923 module_exit(xpt2046_exit);
 924
 925 MODULE_DESCRIPTION("rk2818 spi xpt2046 TouchScreen Driver");
 926 MODULE_LICENSE("GPL");
 927 MODULE_ALIAS("spi:xpt2046");