drivers/input/touchscreen/tnetv107x-ts.c

   1 /*
   2  * Texas Instruments TNETV107X Touchscreen Driver
   3  *
   4  * Copyright (C) 2010 Texas Instruments
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation version 2.
   9  *
  10  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  11  * kind, whether express or implied; without even the implied warranty
  12  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/err.h>
  18 #include <linux/errno.h>
  19 #include <linux/input.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/slab.h>
  23 #include <linux/delay.h>
  24 #include <linux/ctype.h>
  25 #include <linux/io.h>
  26 #include <linux/clk.h>
  27
  28 #include <mach/tnetv107x.h>
  29
  30 #define TSC_PENUP_POLL          (HZ / 5)
  31 #define IDLE_TIMEOUT            100 /* msec */
  32
  33 /*
  34  * The first and last samples of a touch interval are usually garbage and need
  35  * to be filtered out with these devices.  The following definitions control
  36  * the number of samples skipped.
  37  */
  38 #define TSC_HEAD_SKIP           1
  39 #define TSC_TAIL_SKIP           1
  40 #define TSC_SKIP                (TSC_HEAD_SKIP + TSC_TAIL_SKIP + 1)
  41 #define TSC_SAMPLES             (TSC_SKIP + 1)
  42
  43 /* Register Offsets */
  44 struct tsc_regs {
  45         u32     rev;
  46         u32     tscm;
  47         u32     bwcm;
  48         u32     swc;
  49         u32     adcchnl;
  50         u32     adcdata;
  51         u32     chval[4];
  52 };
  53
  54 /* TSC Mode Configuration Register (tscm) bits */
  55 #define WMODE           BIT(0)
  56 #define TSKIND          BIT(1)
  57 #define ZMEASURE_EN     BIT(2)
  58 #define IDLE            BIT(3)
  59 #define TSC_EN          BIT(4)
  60 #define STOP            BIT(5)
  61 #define ONE_SHOT        BIT(6)
  62 #define SINGLE          BIT(7)
  63 #define AVG             BIT(8)
  64 #define AVGNUM(x)       (((x) & 0x03) <<  9)
  65 #define PVSTC(x)        (((x) & 0x07) << 11)
  66 #define PON             BIT(14)
  67 #define PONBG           BIT(15)
  68 #define AFERST          BIT(16)
  69
  70 /* ADC DATA Capture Register bits */
  71 #define DATA_VALID      BIT(16)
  72
  73 /* Register Access Macros */
  74 #define tsc_read(ts, reg)               __raw_readl(&(ts)->regs->reg)
  75 #define tsc_write(ts, reg, val)         __raw_writel(val, &(ts)->regs->reg);
  76 #define tsc_set_bits(ts, reg, val)      \
  77         tsc_write(ts, reg, tsc_read(ts, reg) | (val))
  78 #define tsc_clr_bits(ts, reg, val)      \
  79         tsc_write(ts, reg, tsc_read(ts, reg) & ~(val))
  80
  81 struct sample {
  82         int x, y, p;
  83 };
  84
  85 struct tsc_data {
  86         struct input_dev                *input_dev;
  87         struct resource                 *res;
  88         struct tsc_regs __iomem         *regs;
  89         struct timer_list               timer;
  90         spinlock_t                      lock;
  91         struct clk                      *clk;
  92         struct device                   *dev;
  93         int                             sample_count;
  94         struct sample                   samples[TSC_SAMPLES];
  95         int                             tsc_irq;
  96 };
  97
  98 static int tsc_read_sample(struct tsc_data *ts, struct sample* sample)
  99 {
 100         int     x, y, z1, z2, t, p = 0;
 101         u32     val;
 102
 103         val = tsc_read(ts, chval[0]);
 104         if (val & DATA_VALID)
 105                 x = val & 0xffff;
 106         else
 107                 return -EINVAL;
 108
 109         y  = tsc_read(ts, chval[1]) & 0xffff;
 110         z1 = tsc_read(ts, chval[2]) & 0xffff;
 111         z2 = tsc_read(ts, chval[3]) & 0xffff;
 112
 113         if (z1) {
 114                 t = ((600 * x) * (z2 - z1));
 115                 p = t / (u32) (z1 << 12);
 116                 if (p < 0)
 117                         p = 0;
 118         }
 119
 120         sample->x  = x;
 121         sample->y  = y;
 122         sample->p  = p;
 123
 124         return 0;
 125 }
 126
 127 static void tsc_poll(unsigned long data)
 128 {
 129         struct tsc_data *ts = (struct tsc_data *)data;
 130         unsigned long flags;
 131         int i, val, x, y, p;
 132
 133         spin_lock_irqsave(&ts->lock, flags);
 134
 135         if (ts->sample_count >= TSC_SKIP) {
 136                 input_report_abs(ts->input_dev, ABS_PRESSURE, 0);
 137                 input_report_key(ts->input_dev, BTN_TOUCH, 0);
 138                 input_sync(ts->input_dev);
 139         } else if (ts->sample_count > 0) {
 140                 /*
 141                  * A touch event lasted less than our skip count.  Salvage and
 142                  * report anyway.
 143                  */
 144                 for (i = 0, val = 0; i < ts->sample_count; i++)
 145                         val += ts->samples[i].x;
 146                 x = val / ts->sample_count;
 147
 148                 for (i = 0, val = 0; i < ts->sample_count; i++)
 149                         val += ts->samples[i].y;
 150                 y = val / ts->sample_count;
 151
 152                 for (i = 0, val = 0; i < ts->sample_count; i++)
 153                         val += ts->samples[i].p;
 154                 p = val / ts->sample_count;
 155
 156                 input_report_abs(ts->input_dev, ABS_X, x);
 157                 input_report_abs(ts->input_dev, ABS_Y, y);
 158                 input_report_abs(ts->input_dev, ABS_PRESSURE, p);
 159                 input_report_key(ts->input_dev, BTN_TOUCH, 1);
 160                 input_sync(ts->input_dev);
 161         }
 162
 163         ts->sample_count = 0;
 164
 165         spin_unlock_irqrestore(&ts->lock, flags);
 166 }
 167
 168 static irqreturn_t tsc_irq(int irq, void *dev_id)
 169 {
 170         struct tsc_data *ts = (struct tsc_data *)dev_id;
 171         struct sample *sample;
 172         int index;
 173
 174         spin_lock(&ts->lock);
 175
 176         index = ts->sample_count % TSC_SAMPLES;
 177         sample = &ts->samples[index];
 178         if (tsc_read_sample(ts, sample) < 0)
 179                 goto out;
 180
 181         if (++ts->sample_count >= TSC_SKIP) {
 182                 index = (ts->sample_count - TSC_TAIL_SKIP - 1) % TSC_SAMPLES;
 183                 sample = &ts->samples[index];
 184
 185                 input_report_abs(ts->input_dev, ABS_X, sample->x);
 186                 input_report_abs(ts->input_dev, ABS_Y, sample->y);
 187                 input_report_abs(ts->input_dev, ABS_PRESSURE, sample->p);
 188                 if (ts->sample_count == TSC_SKIP)
 189                         input_report_key(ts->input_dev, BTN_TOUCH, 1);
 190                 input_sync(ts->input_dev);
 191         }
 192         mod_timer(&ts->timer, jiffies + TSC_PENUP_POLL);
 193 out:
 194         spin_unlock(&ts->lock);
 195         return IRQ_HANDLED;
 196 }
 197
 198 static int tsc_start(struct input_dev *dev)
 199 {
 200         struct tsc_data *ts = input_get_drvdata(dev);
 201         unsigned long timeout = jiffies + msecs_to_jiffies(IDLE_TIMEOUT);
 202         u32 val;
 203
 204         clk_enable(ts->clk);
 205
 206         /* Go to idle mode, before any initialization */
 207         while (time_after(timeout, jiffies)) {
 208                 if (tsc_read(ts, tscm) & IDLE)
 209                         break;
 210         }
 211
 212         if (time_before(timeout, jiffies)) {
 213                 dev_warn(ts->dev, "timeout waiting for idle\n");
 214                 clk_disable(ts->clk);
 215                 return -EIO;
 216         }
 217
 218         /* Configure TSC Control register*/
 219         val = (PONBG | PON | PVSTC(4) | ONE_SHOT | ZMEASURE_EN);
 220         tsc_write(ts, tscm, val);
 221
 222         /* Bring TSC out of reset: Clear AFE reset bit */
 223         val &= ~(AFERST);
 224         tsc_write(ts, tscm, val);
 225
 226         /* Configure all pins for hardware control*/
 227         tsc_write(ts, bwcm, 0);
 228
 229         /* Finally enable the TSC */
 230         tsc_set_bits(ts, tscm, TSC_EN);
 231
 232         return 0;
 233 }
 234
 235 static void tsc_stop(struct input_dev *dev)
 236 {
 237         struct tsc_data *ts = input_get_drvdata(dev);
 238
 239         tsc_clr_bits(ts, tscm, TSC_EN);
 240         synchronize_irq(ts->tsc_irq);
 241         del_timer_sync(&ts->timer);
 242         clk_disable(ts->clk);
 243 }
 244
 245 static int __devinit tsc_probe(struct platform_device *pdev)
 246 {
 247         struct device *dev = &pdev->dev;
 248         struct tsc_data *ts;
 249         int error = 0;
 250         u32 rev = 0;
 251
 252         ts = kzalloc(sizeof(struct tsc_data), GFP_KERNEL);
 253         if (!ts) {
 254                 dev_err(dev, "cannot allocate device info\n");
 255                 return -ENOMEM;
 256         }
 257
 258         ts->dev = dev;
 259         spin_lock_init(&ts->lock);
 260         setup_timer(&ts->timer, tsc_poll, (unsigned long)ts);
 261         platform_set_drvdata(pdev, ts);
 262
 263         ts->tsc_irq = platform_get_irq(pdev, 0);
 264         if (ts->tsc_irq < 0) {
 265                 dev_err(dev, "cannot determine device interrupt\n");
 266                 error = -ENODEV;
 267                 goto error_res;
 268         }
 269
 270         ts->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 271         if (!ts->res) {
 272                 dev_err(dev, "cannot determine register area\n");
 273                 error = -ENODEV;
 274                 goto error_res;
 275         }
 276
 277         if (!request_mem_region(ts->res->start, resource_size(ts->res),
 278                                 pdev->name)) {
 279                 dev_err(dev, "cannot claim register memory\n");
 280                 ts->res = NULL;
 281                 error = -EINVAL;
 282                 goto error_res;
 283         }
 284
 285         ts->regs = ioremap(ts->res->start, resource_size(ts->res));
 286         if (!ts->regs) {
 287                 dev_err(dev, "cannot map register memory\n");
 288                 error = -ENOMEM;
 289                 goto error_map;
 290         }
 291
 292         ts->clk = clk_get(dev, NULL);
 293         if (IS_ERR(ts->clk)) {
 294                 dev_err(dev, "cannot claim device clock\n");
 295                 error = PTR_ERR(ts->clk);
 296                 goto error_clk;
 297         }
 298
 299         error = request_threaded_irq(ts->tsc_irq, NULL, tsc_irq, 0,
 300                                      dev_name(dev), ts);
 301         if (error < 0) {
 302                 dev_err(ts->dev, "Could not allocate ts irq\n");
 303                 goto error_irq;
 304         }
 305
 306         ts->input_dev = input_allocate_device();
 307         if (!ts->input_dev) {
 308                 dev_err(dev, "cannot allocate input device\n");
 309                 error = -ENOMEM;
 310                 goto error_input;
 311         }
 312         input_set_drvdata(ts->input_dev, ts);
 313
 314         ts->input_dev->name       = pdev->name;
 315         ts->input_dev->id.bustype = BUS_HOST;
 316         ts->input_dev->dev.parent = &pdev->dev;
 317         ts->input_dev->open       = tsc_start;
 318         ts->input_dev->close      = tsc_stop;
 319
 320         clk_enable(ts->clk);
 321         rev = tsc_read(ts, rev);
 322         ts->input_dev->id.product = ((rev >>  8) & 0x07);
 323         ts->input_dev->id.version = ((rev >> 16) & 0xfff);
 324         clk_disable(ts->clk);
 325
 326         __set_bit(EV_KEY,    ts->input_dev->evbit);
 327         __set_bit(EV_ABS,    ts->input_dev->evbit);
 328         __set_bit(BTN_TOUCH, ts->input_dev->keybit);
 329
 330         input_set_abs_params(ts->input_dev, ABS_X, 0, 0xffff, 5, 0);
 331         input_set_abs_params(ts->input_dev, ABS_Y, 0, 0xffff, 5, 0);
 332         input_set_abs_params(ts->input_dev, ABS_PRESSURE, 0, 4095, 128, 0);
 333
 334         error = input_register_device(ts->input_dev);
 335         if (error < 0) {
 336                 dev_err(dev, "failed input device registration\n");
 337                 goto error_reg;
 338         }
 339
 340         return 0;
 341
 342 error_reg:
 343         input_free_device(ts->input_dev);
 344 error_input:
 345         free_irq(ts->tsc_irq, ts);
 346 error_irq:
 347         clk_put(ts->clk);
 348 error_clk:
 349         iounmap(ts->regs);
 350 error_map:
 351         release_mem_region(ts->res->start, resource_size(ts->res));
 352 error_res:
 353         platform_set_drvdata(pdev, NULL);
 354         kfree(ts);
 355
 356         return error;
 357 }
 358
 359 static int __devexit tsc_remove(struct platform_device *pdev)
 360 {
 361         struct tsc_data *ts = platform_get_drvdata(pdev);
 362
 363         input_unregister_device(ts->input_dev);
 364         free_irq(ts->tsc_irq, ts);
 365         clk_put(ts->clk);
 366         iounmap(ts->regs);
 367         release_mem_region(ts->res->start, resource_size(ts->res));
 368         platform_set_drvdata(pdev, NULL);
 369         kfree(ts);
 370
 371         return 0;
 372 }
 373
 374 static struct platform_driver tsc_driver = {
 375         .probe          = tsc_probe,
 376         .remove         = __devexit_p(tsc_remove),
 377         .driver.name    = "tnetv107x-ts",
 378         .driver.owner   = THIS_MODULE,
 379 };
 380
 381 static int __init tsc_init(void)
 382 {
 383         return platform_driver_register(&tsc_driver);
 384 }
 385
 386 static void __exit tsc_exit(void)
 387 {
 388         platform_driver_unregister(&tsc_driver);
 389 }
 390
 391 module_init(tsc_init);
 392 module_exit(tsc_exit);
 393
 394 MODULE_AUTHOR("Cyril Chemparathy");
 395 MODULE_DESCRIPTION("TNETV107X Touchscreen Driver");
 396 MODULE_ALIAS("platform: tnetv107x-ts");
 397 MODULE_LICENSE("GPL");