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 struct xpt2046_platform_data xpt2046_info = {
 205         .model                  = 2046,
 206         .keep_vref_on   = 1,
 207         .swap_xy                = 1,
 208         .x_min                  = 0,
 209         .x_max                  = 800,
 210         .y_min                  = 0,
 211         .y_max                  = 480,
 212         .debounce_max           = 7,
 213         .debounce_rep           = DEBOUNCE_REPTIME,
 214         .debounce_tol           = 20,
 215 #if defined(CONFIG_MACH_RAHO)
 216     .gpio_pendown               = RK2818_PIN_PE1,
 217 #else
 218         .gpio_pendown           = RK2818_PIN_PE3,
 219 #endif
 220         .penirq_recheck_delay_usecs = 1,
 221
 222 };
 223 static void xpt2046_enable(struct xpt2046 *ts);
 224 static void xpt2046_disable(struct xpt2046 *ts);
 225
 226 static int device_suspended(struct device *dev)
 227 {
 228         struct xpt2046 *ts = dev_get_drvdata(dev);
 229         return ts->is_suspended || ts->disabled;
 230 }
 231
 232 static int xpt2046_read12_dfr(struct device *dev, unsigned command)
 233 {
 234         struct spi_device       *spi = to_spi_device(dev);
 235         struct xpt2046          *ts = dev_get_drvdata(dev);
 236         struct dfr_req          *req = kzalloc(sizeof *req, GFP_KERNEL);
 237         int                     status;
 238
 239         if (!req)
 240                 return -ENOMEM;
 241
 242         spi_message_init(&req->msg);
 243
 244         /* take sample */
 245         req->command = (u8) command;
 246         req->xfer[0].tx_buf = &req->command;
 247         req->xfer[0].len = 1;
 248         spi_message_add_tail(&req->xfer[0], &req->msg);
 249
 250         req->xfer[1].rx_buf = &req->sample;
 251         req->xfer[1].len = 2;
 252         spi_message_add_tail(&req->xfer[1], &req->msg);
 253
 254         /* converter in low power mode & enable PENIRQ */
 255         req->pwrdown= PWRDOWN;
 256         req->xfer[2].tx_buf = &req->pwrdown;
 257         req->xfer[2].len = 1;
 258         spi_message_add_tail(&req->xfer[2], &req->msg);
 259
 260         req->xfer[3].rx_buf = &req->dummy;
 261         req->xfer[3].len = 2;
 262         CS_CHANGE(req->xfer[3]);
 263         spi_message_add_tail(&req->xfer[3], &req->msg);
 264
 265         ts->irq_disabled = 1;
 266         disable_irq(spi->irq);
 267         status = spi_sync(spi, &req->msg);
 268         ts->irq_disabled = 0;
 269         enable_irq(spi->irq);
 270
 271         if (status == 0) {
 272                 /* on-wire is a must-ignore bit, a BE12 value, then padding */
 273                 status = be16_to_cpu(req->sample);
 274                 status = status >> 3;
 275                 status &= 0x0fff;
 276                 xpt2046printk("***>%s:status=%d\n",__FUNCTION__,status);
 277         }
 278
 279         kfree(req);
 280         return status;
 281 }
 282
 283
 284
 285 /*--------------------------------------------------------------------------*/
 286
 287 static int get_pendown_state(struct xpt2046 *ts)
 288 {
 289         if (ts->get_pendown_state)
 290                 return ts->get_pendown_state();
 291
 292         return !gpio_get_value(ts->gpio_pendown);
 293 }
 294
 295 static void null_wait_for_sync(void)
 296 {
 297
 298 }
 299
 300 /*
 301  * PENIRQ only kicks the timer.  The timer only reissues the SPI transfer,
 302  * to retrieve touchscreen status.
 303  *
 304  * The SPI transfer completion callback does the real work.  It reports
 305  * touchscreen events and reactivates the timer (or IRQ) as appropriate.
 306  */
 307
 308 static void xpt2046_rx(void *xpt)
 309 {
 310         struct xpt2046          *ts = xpt;
 311         struct xpt2046_packet   *packet = ts->packet;
 312         unsigned                Rt = 1;
 313         u16                     x, y;
 314
 315         /* xpt2046_rx_val() did in-place conversion (including byteswap) from
 316          * on-the-wire format as part of debouncing to get stable readings.
 317          */
 318         x = packet->tc.x;
 319         y = packet->tc.y;
 320
 321         xpt2046printk("***>%s:x=%d,y=%d\n",__FUNCTION__,x,y);
 322
 323         /* range filtering */
 324         if (x == MAX_12BIT)
 325                 x = 0;
 326
 327         /* Sample found inconsistent by debouncing or pressure is beyond
 328          * the maximum. Don't report it to user space, repeat at least
 329          * once more the measurement
 330          */
 331         if (packet->tc.ignore) {
 332
 333                 xpt2046printk("***>%s:ignored=%d\n",__FUNCTION__,packet->tc.ignore);
 334
 335                 hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
 336                               HRTIMER_MODE_REL);
 337                 return;
 338         }
 339
 340         /* Maybe check the pendown state before reporting. This discards
 341          * false readings when the pen is lifted.
 342          */
 343         if (ts->penirq_recheck_delay_usecs) {
 344                 udelay(ts->penirq_recheck_delay_usecs);
 345                 if (!get_pendown_state(ts))
 346                 {
 347                         xpt2046printk("***>%s:get_pendown_state(ts)==0,discard false reading\n",__FUNCTION__);
 348                         Rt = 0;
 349                 }
 350         }
 351
 352         /* NOTE: We can't rely on the pressure to determine the pen down
 353          * state, even this controller has a pressure sensor.  The pressure
 354          * value can fluctuate for quite a while after lifting the pen and
 355          * in some cases may not even settle at the expected value.
 356          *
 357          * The only safe way to check for the pen up condition is in the
 358          * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
 359          */
 360         if (Rt) {
 361                 struct input_dev *input = ts->input;
 362                 if (!ts->pendown) {
 363                         input_report_key(input, BTN_TOUCH, 1);
 364                         ts->pendown = 1;
 365                         xpt2046printk("***>%s:input_report_key(pen down)\n",__FUNCTION__);
 366                 }
 367
 368                 x =  AD_TO_X(x);
 369                 y =  AD_TO_Y(y);
 370
 371                 if (ts->swap_xy)
 372                         swap(x, y);
 373
 374                 input_report_abs(input, ABS_X, x);
 375                 input_report_abs(input, ABS_Y, y);
 376
 377                 input_sync(input);
 378                 xpt2046printk("***>%s:input_report_abs(%4d/%4d)\n",__FUNCTION__,x, y);
 379         }
 380
 381         hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
 382                         HRTIMER_MODE_REL);
 383 }
 384
 385 static int xpt2046_debounce(void *xpt, int data_idx, int *val)
 386 {
 387         struct xpt2046          *ts = xpt;
 388         static int average_val[2];
 389
 390
 391         xpt2046printk("***>%s:%d,%d,%d,%d,%d,%d,%d,%d\n",__FUNCTION__,
 392                 data_idx,ts->last_read,
 393           ts->read_cnt,ts->debounce_max,
 394                 abs(ts->last_read - *val),ts->debounce_tol,
 395                 ts->read_rep,ts->debounce_rep);
 396
 397         if(*val == 4095 || *val == 0)
 398         {
 399                 ts->read_cnt = 0;
 400                 ts->last_read = 0;
 401                 memset(average_val,0,sizeof(average_val));
 402                 xpt2046printk("***>%s:*val == 4095 || *val == 0\n",__FUNCTION__);
 403                 return XPT2046_FILTER_IGNORE;
 404         }
 405         /* discard the first sample. */
 406         if(!ts->read_cnt)
 407         {
 408                 ts->read_cnt++;
 409                 return XPT2046_FILTER_REPEAT;
 410         }
 411
 412         if (ts->read_cnt==1 || (abs(ts->last_read - *val) > ts->debounce_tol)) {
 413                 /* Start over collecting consistent readings. */
 414                 ts->read_rep = 1;
 415                 average_val[data_idx] = *val;
 416                 /* Repeat it, if this was the first read or the read
 417                  * wasn't consistent enough. */
 418                 if (ts->read_cnt < ts->debounce_max) {
 419                         ts->last_read = *val;
 420                         ts->read_cnt++;
 421                         return XPT2046_FILTER_REPEAT;
 422                 } else {
 423                         /* Maximum number of debouncing reached and still
 424                          * not enough number of consistent readings. Abort
 425                          * the whole sample, repeat it in the next sampling
 426                          * period.
 427                          */
 428                         ts->read_cnt = 0;
 429                         ts->last_read = 0;
 430                         memset(average_val,0,sizeof(average_val));
 431                         xpt2046printk("***>%s:XPT2046_FILTER_IGNORE\n",__FUNCTION__);
 432                         return XPT2046_FILTER_IGNORE;
 433                 }
 434         }
 435         else {
 436                 average_val[data_idx] += *val;
 437
 438                 if (++ts->read_rep >= ts->debounce_rep) {
 439                         /* Got a good reading for this coordinate,
 440                          * go for the next one. */
 441                         ts->read_cnt = 0;
 442                         ts->read_rep = 0;
 443                         ts->last_read = 0;
 444                         *val = average_val[data_idx]/(ts->debounce_rep);
 445                         return XPT2046_FILTER_OK;
 446                 } else {
 447                         /* Read more values that are consistent. */
 448                         ts->read_cnt++;
 449
 450                         return XPT2046_FILTER_REPEAT;
 451                 }
 452         }
 453 }
 454
 455 static int xpt2046_no_filter(void *xpt, int data_idx, int *val)
 456 {
 457         return XPT2046_FILTER_OK;
 458 }
 459
 460 static void xpt2046_rx_val(void *xpt)
 461 {
 462         struct xpt2046 *ts = xpt;
 463         struct xpt2046_packet *packet = ts->packet;
 464         struct spi_message *m;
 465         struct spi_transfer *t;
 466         int val;
 467         int action;
 468         int status;
 469
 470         m = &ts->msg[ts->msg_idx];
 471         t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
 472
 473         /* adjust:  on-wire is a must-ignore bit, a BE12 value, then padding;
 474          * built from two 8 bit values written msb-first.
 475          */
 476         val = (be16_to_cpup((__be16 *)t->rx_buf) >> 3) & 0x0fff;
 477
 478         xpt2046printk("***>%s:value=%d\n",__FUNCTION__,val);
 479
 480         action = ts->filter(ts->filter_data, ts->msg_idx, &val);
 481         switch (action) {
 482         case XPT2046_FILTER_REPEAT:
 483                 break;
 484         case XPT2046_FILTER_IGNORE:
 485                 packet->tc.ignore = 1;
 486                 /* Last message will contain xpt2046_rx() as the
 487                  * completion function.
 488                  */
 489                 m = ts->last_msg;
 490                 break;
 491         case XPT2046_FILTER_OK:
 492                 *(u16 *)t->rx_buf = val;
 493                 packet->tc.ignore = 0;
 494                 m = &ts->msg[++ts->msg_idx];
 495                 break;
 496         default:
 497                 BUG();
 498         }
 499         ts->wait_for_sync();
 500         status = spi_async(ts->spi, m);
 501         if (status)
 502                 dev_err(&ts->spi->dev, "spi_async --> %d\n",
 503                                 status);
 504 }
 505
 506 static enum hrtimer_restart xpt2046_timer(struct hrtimer *handle)
 507 {
 508         struct xpt2046  *ts = container_of(handle, struct xpt2046, timer);
 509         int             status = 0;
 510
 511         spin_lock(&ts->lock);
 512
 513         if (unlikely(!get_pendown_state(ts) ||
 514                      device_suspended(&ts->spi->dev))) {
 515                 if (ts->pendown) {
 516                         struct input_dev *input = ts->input;
 517                         input_report_key(input, BTN_TOUCH, 0);
 518                         input_sync(input);
 519
 520                         ts->pendown = 0;
 521
 522                         xpt2046printk("***>%s:input_report_key(The touchscreen up)\n",__FUNCTION__);
 523                 }
 524
 525                 /* measurement cycle ended */
 526                 if (!device_suspended(&ts->spi->dev)) {
 527                         xpt2046printk("***>%s:device_suspended==0\n",__FUNCTION__);
 528                         ts->irq_disabled = 0;
 529                         enable_irq(ts->spi->irq);
 530                 }
 531                 ts->pending = 0;
 532         } else {
 533                 /* pen is still down, continue with the measurement */
 534                 xpt2046printk("***>%s:pen is still down, continue with the measurement\n",__FUNCTION__);
 535                 ts->msg_idx = 0;
 536                 ts->wait_for_sync();
 537                 status = spi_async(ts->spi, &ts->msg[0]);
 538                 if (status)
 539                         dev_err(&ts->spi->dev, "spi_async --> %d\n", status);
 540         }
 541
 542         spin_unlock(&ts->lock);
 543         return HRTIMER_NORESTART;
 544 }
 545
 546 static irqreturn_t xpt2046_irq(int irq, void *handle)
 547 {
 548         struct xpt2046 *ts = handle;
 549         unsigned long flags;
 550
 551         xpt2046printk("***>%s.....%s.....%d\n",__FILE__,__FUNCTION__,__LINE__);
 552
 553         spin_lock_irqsave(&ts->lock, flags);
 554
 555         if (likely(get_pendown_state(ts))) {
 556                 if (!ts->irq_disabled) {
 557                         /* The ARM do_simple_IRQ() dispatcher doesn't act
 558                          * like the other dispatchers:  it will report IRQs
 559                          * even after they've been disabled.  We work around
 560                          * that here.  (The "generic irq" framework may help...)
 561                          */
 562                         ts->irq_disabled = 1;
 563                         disable_irq_nosync(ts->spi->irq);
 564                         ts->pending = 1;
 565                         hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
 566                                         HRTIMER_MODE_REL);
 567                 }
 568         }
 569         spin_unlock_irqrestore(&ts->lock, flags);
 570
 571         return IRQ_HANDLED;
 572 }
 573
 574 /*--------------------------------------------------------------------------*/
 575
 576 /* Must be called with ts->lock held */
 577 static void xpt2046_disable(struct xpt2046 *ts)
 578 {
 579         if (ts->disabled)
 580                 return;
 581
 582         ts->disabled = 1;
 583
 584         /* are we waiting for IRQ, or polling? */
 585         if (!ts->pending) {
 586                 ts->irq_disabled = 1;
 587                 disable_irq(ts->spi->irq);
 588         } else {
 589                 /* the timer will run at least once more, and
 590                  * leave everything in a clean state, IRQ disabled
 591                  */
 592                 while (ts->pending) {
 593                         spin_unlock_irq(&ts->lock);
 594                         msleep(1);
 595                         spin_lock_irq(&ts->lock);
 596                 }
 597         }
 598
 599         /* we know the chip's in lowpower mode since we always
 600          * leave it that way after every request
 601          */
 602 }
 603
 604 /* Must be called with ts->lock held */
 605 static void xpt2046_enable(struct xpt2046 *ts)
 606 {
 607         if (!ts->disabled)
 608                 return;
 609
 610         ts->disabled = 0;
 611         ts->irq_disabled = 0;
 612         enable_irq(ts->spi->irq);
 613 }
 614
 615 static int xpt2046_suspend(struct spi_device *spi, pm_message_t message)
 616 {
 617         struct xpt2046 *ts = dev_get_drvdata(&spi->dev);
 618
 619         spin_lock_irq(&ts->lock);
 620
 621         ts->is_suspended = 1;
 622         xpt2046_disable(ts);
 623
 624         spin_unlock_irq(&ts->lock);
 625
 626         return 0;
 627
 628 }
 629
 630 static int xpt2046_resume(struct spi_device *spi)
 631 {
 632         struct xpt2046 *ts = dev_get_drvdata(&spi->dev);
 633
 634         spin_lock_irq(&ts->lock);
 635
 636         ts->is_suspended = 0;
 637         xpt2046_enable(ts);
 638
 639         spin_unlock_irq(&ts->lock);
 640
 641         return 0;
 642 }
 643
 644 static int __devinit setup_pendown(struct spi_device *spi, struct xpt2046 *ts)
 645 {
 646         struct xpt2046_platform_data *pdata = spi->dev.platform_data;
 647         int err;
 648
 649         /* REVISIT when the irq can be triggered active-low, or if for some
 650          * reason the touchscreen isn't hooked up, we don't need to access
 651          * the pendown state.
 652          */
 653         if (!pdata->get_pendown_state && !gpio_is_valid(pdata->gpio_pendown)) {
 654                 dev_err(&spi->dev, "no get_pendown_state nor gpio_pendown?\n");
 655                 return -EINVAL;
 656         }
 657
 658         if (pdata->get_pendown_state) {
 659                 ts->get_pendown_state = pdata->get_pendown_state;
 660                 return 0;
 661         }
 662
 663     if (pdata->io_init) {
 664         err = pdata->io_init();
 665         if (err)
 666             dev_err(&spi->dev, "xpt2046 io_init fail\n");
 667     }
 668
 669         err = gpio_request(pdata->gpio_pendown, "xpt2046_pendown");
 670         if (err) {
 671                 dev_err(&spi->dev, "failed to request pendown GPIO%d\n",
 672                                 pdata->gpio_pendown);
 673                 return err;
 674         }
 675
 676         ts->gpio_pendown = pdata->gpio_pendown;
 677         return 0;
 678 }
 679
 680 static int __devinit xpt2046_probe(struct spi_device *spi)
 681 {
 682         struct xpt2046                  *ts;
 683         struct xpt2046_packet           *packet;
 684         struct input_dev                *input_dev;
 685         struct xpt2046_platform_data    *pdata = spi->dev.platform_data;
 686         struct spi_message              *m;
 687         struct spi_transfer             *x;
 688         int                             vref;
 689         int                             err;
 690
 691
 692
 693         if (!spi->irq) {
 694                 dev_dbg(&spi->dev, "no IRQ?\n");
 695                 return -ENODEV;
 696         }
 697         else{
 698                 spi->irq = gpio_to_irq(spi->irq);
 699                 dev_dbg(&spi->dev, "no IRQ?\n");
 700         }
 701
 702         /*
 703         if (!pdata) {
 704                 spi->dev.platform_data = &xpt2046_info;
 705                 pdata = spi->dev.platform_data;
 706         }
 707     */
 708
 709     if (!pdata) {
 710                 dev_err(&spi->dev, "empty platform_data\n");
 711                 return -EFAULT;
 712     }
 713
 714         /* don't exceed max specified sample rate */
 715         if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
 716                 dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
 717                                 (spi->max_speed_hz/SAMPLE_BITS)/1000);
 718                 return -EINVAL;
 719         }
 720
 721         /* We'd set TX wordsize 8 bits and RX wordsize to 13 bits ... except
 722          * that even if the hardware can do that, the SPI controller driver
 723          * may not.  So we stick to very-portable 8 bit words, both RX and TX.
 724          */
 725         spi->bits_per_word = 8;
 726         spi->mode = SPI_MODE_0;
 727         err = spi_setup(spi);
 728         if (err < 0)
 729                 return err;
 730
 731         ts = kzalloc(sizeof(struct xpt2046), GFP_KERNEL);
 732         packet = kzalloc(sizeof(struct xpt2046_packet), GFP_KERNEL);
 733         input_dev = input_allocate_device();
 734         if (!ts || !packet || !input_dev) {
 735                 err = -ENOMEM;
 736                 goto err_free_mem;
 737         }
 738
 739         dev_set_drvdata(&spi->dev, ts);
 740
 741         ts->packet = packet;
 742         ts->spi = spi;
 743         ts->input = input_dev;
 744         ts->swap_xy = pdata->swap_xy;
 745
 746         hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 747         ts->timer.function = xpt2046_timer;
 748
 749         spin_lock_init(&ts->lock);
 750
 751         ts->model = pdata->model ? : 2046;
 752
 753         if (pdata->filter != NULL) {
 754                 if (pdata->filter_init != NULL) {
 755                         err = pdata->filter_init(pdata, &ts->filter_data);
 756                         if (err < 0)
 757                                 goto err_free_mem;
 758                 }
 759                 ts->filter = pdata->filter;
 760                 ts->filter_cleanup = pdata->filter_cleanup;
 761         } else if (pdata->debounce_max) {
 762                 ts->debounce_max = pdata->debounce_max;
 763                 if (ts->debounce_max < pdata->debounce_rep)
 764                         ts->debounce_max = pdata->debounce_rep;
 765                 ts->debounce_tol = pdata->debounce_tol;
 766                 ts->debounce_rep = pdata->debounce_rep;
 767                 ts->filter = xpt2046_debounce;
 768                 ts->filter_data = ts;
 769         } else
 770                 ts->filter = xpt2046_no_filter;
 771
 772         err = setup_pendown(spi, ts);
 773         if (err)
 774                 goto err_cleanup_filter;
 775
 776         if (pdata->penirq_recheck_delay_usecs)
 777                 ts->penirq_recheck_delay_usecs =
 778                                 pdata->penirq_recheck_delay_usecs;
 779
 780         ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync;
 781
 782         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
 783         snprintf(ts->name, sizeof(ts->name), "XPT%d Touchscreen", ts->model);
 784
 785         input_dev->name = ts->name;
 786         input_dev->phys = ts->phys;
 787         input_dev->dev.parent = &spi->dev;
 788
 789         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 790         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 791         input_set_abs_params(input_dev, ABS_X,
 792                         pdata->x_min ? : 0,
 793                         pdata->x_max ? : MAX_12BIT,
 794                         0, 0);
 795         input_set_abs_params(input_dev, ABS_Y,
 796                         pdata->y_min ? : 0,
 797                         pdata->y_max ? : MAX_12BIT,
 798                         0, 0);
 799
 800         vref = pdata->keep_vref_on;
 801
 802         /* set up the transfers to read touchscreen state; this assumes we
 803          * use formula #2 for pressure, not #3.
 804          */
 805         m = &ts->msg[0];
 806         x = ts->xfer;
 807
 808         spi_message_init(m);
 809
 810         /* y- still on; turn on only y+ (and ADC) */
 811         packet->read_y = READ_Y(vref);
 812         x->tx_buf = &packet->read_y;
 813         x->len = 1;
 814         spi_message_add_tail(x, m);
 815
 816         x++;
 817         x->rx_buf = &packet->tc.y;
 818         x->len = 2;
 819         spi_message_add_tail(x, m);
 820
 821         m->complete = xpt2046_rx_val;
 822         m->context = ts;
 823
 824         m++;
 825         spi_message_init(m);
 826
 827         /* turn y- off, x+ on, then leave in lowpower */
 828         x++;
 829         packet->read_x = READ_X(vref);
 830         x->tx_buf = &packet->read_x;
 831         x->len = 1;
 832         spi_message_add_tail(x, m);
 833
 834         x++;
 835         x->rx_buf = &packet->tc.x;
 836         x->len = 2;
 837         spi_message_add_tail(x, m);
 838
 839         m->complete = xpt2046_rx_val;
 840         m->context = ts;
 841
 842         /* power down */
 843         m++;
 844         spi_message_init(m);
 845
 846         x++;
 847         packet->pwrdown = PWRDOWN;
 848         x->tx_buf = &packet->pwrdown;
 849         x->len = 1;
 850         spi_message_add_tail(x, m);
 851
 852         x++;
 853         x->rx_buf = &packet->dummy;
 854         x->len = 2;
 855         CS_CHANGE(*x);
 856         spi_message_add_tail(x, m);
 857
 858         m->complete = xpt2046_rx;
 859         m->context = ts;
 860
 861         ts->last_msg = m;
 862
 863         if (request_irq(spi->irq, xpt2046_irq, IRQF_TRIGGER_FALLING,
 864                         spi->dev.driver->name, ts)) {
 865                 printk("%s:trying pin change workaround on irq %d\n",__FUNCTION__,spi->irq);
 866                 err = request_irq(spi->irq, xpt2046_irq,
 867                                   IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
 868                                   spi->dev.driver->name, ts);
 869                 if (err) {
 870                         dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
 871                         goto err_free_gpio;
 872                 }
 873         }
 874         xpt2046printk("***>%s:touchscreen irq %d\n",__FUNCTION__,spi->irq);
 875
 876         /* take a first sample, leaving nPENIRQ active and vREF off; avoid
 877          * the touchscreen, in case it's not connected.
 878          */
 879         xpt2046_read12_dfr(&spi->dev,READ_X(1));
 880
 881         err = input_register_device(input_dev);
 882         if (err)
 883                 goto err_remove_attr_group;
 884   printk("xpt2046_ts: driver initialized\n");
 885         return 0;
 886
 887  err_remove_attr_group:
 888         free_irq(spi->irq, ts);
 889  err_free_gpio:
 890         if (ts->gpio_pendown != -1)
 891                 gpio_free(ts->gpio_pendown);
 892  err_cleanup_filter:
 893         if (ts->filter_cleanup)
 894                 ts->filter_cleanup(ts->filter_data);
 895  err_free_mem:
 896         input_free_device(input_dev);
 897         kfree(packet);
 898         kfree(ts);
 899         return err;
 900 }
 901
 902 static int __devexit xpt2046_remove(struct spi_device *spi)
 903 {
 904         struct xpt2046          *ts = dev_get_drvdata(&spi->dev);
 905
 906         input_unregister_device(ts->input);
 907
 908         xpt2046_suspend(spi, PMSG_SUSPEND);
 909
 910         free_irq(ts->spi->irq, ts);
 911         /* suspend left the IRQ disabled */
 912         enable_irq(ts->spi->irq);
 913
 914         if (ts->gpio_pendown != -1)
 915                 gpio_free(ts->gpio_pendown);
 916
 917         if (ts->filter_cleanup)
 918                 ts->filter_cleanup(ts->filter_data);
 919
 920         kfree(ts->packet);
 921         kfree(ts);
 922
 923         dev_dbg(&spi->dev, "unregistered touchscreen\n");
 924         return 0;
 925 }
 926
 927 static struct spi_driver xpt2046_driver = {
 928         .driver = {
 929                 .name   = "xpt2046_ts",
 930                 .bus    = &spi_bus_type,
 931                 .owner  = THIS_MODULE,
 932         },
 933         .probe          = xpt2046_probe,
 934         .remove         = __devexit_p(xpt2046_remove),
 935         .suspend        = xpt2046_suspend,
 936         .resume         = xpt2046_resume,
 937 };
 938
 939 static int __init xpt2046_init(void)
 940 {
 941         return spi_register_driver(&xpt2046_driver);
 942 }
 943 module_init(xpt2046_init);
 944
 945 static void __exit xpt2046_exit(void)
 946 {
 947         spi_unregister_driver(&xpt2046_driver);
 948 }
 949 module_exit(xpt2046_exit);
 950
 951 MODULE_DESCRIPTION("rk2818 spi xpt2046 TouchScreen Driver");
 952 MODULE_LICENSE("GPL");
 953 MODULE_ALIAS("spi:xpt2046");