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