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