drivers/input/touchscreen/atmel_tsadcc.c

   1 /*
   2  *  Atmel Touch Screen Driver
   3  *
   4  *  Copyright (c) 2008 ATMEL
   5  *  Copyright (c) 2008 Dan Liang
   6  *  Copyright (c) 2008 TimeSys Corporation
   7  *  Copyright (c) 2008 Justin Waters
   8  *
   9  *  Based on touchscreen code from Atmel Corporation.
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License version 2 as
  13  *  published by the Free Software Foundation.
  14  */
  15 #include <linux/err.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/input.h>
  19 #include <linux/slab.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/clk.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/io.h>
  24 #include <linux/platform_data/atmel.h>
  25 #include <mach/cpu.h>
  26
  27 /* Register definitions based on AT91SAM9RL64 preliminary draft datasheet */
  28
  29 #define ATMEL_TSADCC_CR         0x00    /* Control register */
  30 #define   ATMEL_TSADCC_SWRST    (1 << 0)        /* Software Reset*/
  31 #define   ATMEL_TSADCC_START    (1 << 1)        /* Start conversion */
  32
  33 #define ATMEL_TSADCC_MR         0x04    /* Mode register */
  34 #define   ATMEL_TSADCC_TSAMOD   (3    <<  0)    /* ADC mode */
  35 #define     ATMEL_TSADCC_TSAMOD_ADC_ONLY_MODE   (0x0)   /* ADC Mode */
  36 #define     ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE    (0x1)   /* Touch Screen Only Mode */
  37 #define   ATMEL_TSADCC_LOWRES   (1    <<  4)    /* Resolution selection */
  38 #define   ATMEL_TSADCC_SLEEP    (1    <<  5)    /* Sleep mode */
  39 #define   ATMEL_TSADCC_PENDET   (1    <<  6)    /* Pen Detect selection */
  40 #define   ATMEL_TSADCC_PRES     (1    <<  7)    /* Pressure Measurement Selection */
  41 #define   ATMEL_TSADCC_PRESCAL  (0x3f <<  8)    /* Prescalar Rate Selection */
  42 #define   ATMEL_TSADCC_EPRESCAL (0xff <<  8)    /* Prescalar Rate Selection (Extended) */
  43 #define   ATMEL_TSADCC_STARTUP  (0x7f << 16)    /* Start Up time */
  44 #define   ATMEL_TSADCC_SHTIM    (0xf  << 24)    /* Sample & Hold time */
  45 #define   ATMEL_TSADCC_PENDBC   (0xf  << 28)    /* Pen Detect debouncing time */
  46
  47 #define ATMEL_TSADCC_TRGR       0x08    /* Trigger register */
  48 #define   ATMEL_TSADCC_TRGMOD   (7      <<  0)  /* Trigger mode */
  49 #define     ATMEL_TSADCC_TRGMOD_NONE            (0 << 0)
  50 #define     ATMEL_TSADCC_TRGMOD_EXT_RISING      (1 << 0)
  51 #define     ATMEL_TSADCC_TRGMOD_EXT_FALLING     (2 << 0)
  52 #define     ATMEL_TSADCC_TRGMOD_EXT_ANY         (3 << 0)
  53 #define     ATMEL_TSADCC_TRGMOD_PENDET          (4 << 0)
  54 #define     ATMEL_TSADCC_TRGMOD_PERIOD          (5 << 0)
  55 #define     ATMEL_TSADCC_TRGMOD_CONTINUOUS      (6 << 0)
  56 #define   ATMEL_TSADCC_TRGPER   (0xffff << 16)  /* Trigger period */
  57
  58 #define ATMEL_TSADCC_TSR        0x0C    /* Touch Screen register */
  59 #define   ATMEL_TSADCC_TSFREQ   (0xf <<  0)     /* TS Frequency in Interleaved mode */
  60 #define   ATMEL_TSADCC_TSSHTIM  (0xf << 24)     /* Sample & Hold time */
  61
  62 #define ATMEL_TSADCC_CHER       0x10    /* Channel Enable register */
  63 #define ATMEL_TSADCC_CHDR       0x14    /* Channel Disable register */
  64 #define ATMEL_TSADCC_CHSR       0x18    /* Channel Status register */
  65 #define   ATMEL_TSADCC_CH(n)    (1 << (n))      /* Channel number */
  66
  67 #define ATMEL_TSADCC_SR         0x1C    /* Status register */
  68 #define   ATMEL_TSADCC_EOC(n)   (1 << ((n)+0))  /* End of conversion for channel N */
  69 #define   ATMEL_TSADCC_OVRE(n)  (1 << ((n)+8))  /* Overrun error for channel N */
  70 #define   ATMEL_TSADCC_DRDY     (1 << 16)       /* Data Ready */
  71 #define   ATMEL_TSADCC_GOVRE    (1 << 17)       /* General Overrun Error */
  72 #define   ATMEL_TSADCC_ENDRX    (1 << 18)       /* End of RX Buffer */
  73 #define   ATMEL_TSADCC_RXBUFF   (1 << 19)       /* TX Buffer full */
  74 #define   ATMEL_TSADCC_PENCNT   (1 << 20)       /* Pen contact */
  75 #define   ATMEL_TSADCC_NOCNT    (1 << 21)       /* No contact */
  76
  77 #define ATMEL_TSADCC_LCDR       0x20    /* Last Converted Data register */
  78 #define   ATMEL_TSADCC_DATA     (0x3ff << 0)    /* Channel data */
  79
  80 #define ATMEL_TSADCC_IER        0x24    /* Interrupt Enable register */
  81 #define ATMEL_TSADCC_IDR        0x28    /* Interrupt Disable register */
  82 #define ATMEL_TSADCC_IMR        0x2C    /* Interrupt Mask register */
  83 #define ATMEL_TSADCC_CDR0       0x30    /* Channel Data 0 */
  84 #define ATMEL_TSADCC_CDR1       0x34    /* Channel Data 1 */
  85 #define ATMEL_TSADCC_CDR2       0x38    /* Channel Data 2 */
  86 #define ATMEL_TSADCC_CDR3       0x3C    /* Channel Data 3 */
  87 #define ATMEL_TSADCC_CDR4       0x40    /* Channel Data 4 */
  88 #define ATMEL_TSADCC_CDR5       0x44    /* Channel Data 5 */
  89
  90 #define ATMEL_TSADCC_XPOS       0x50
  91 #define ATMEL_TSADCC_Z1DAT      0x54
  92 #define ATMEL_TSADCC_Z2DAT      0x58
  93
  94 #define PRESCALER_VAL(x)        ((x) >> 8)
  95
  96 #define ADC_DEFAULT_CLOCK       100000
  97
  98 struct atmel_tsadcc {
  99         struct input_dev        *input;
 100         char                    phys[32];
 101         struct clk              *clk;
 102         int                     irq;
 103         unsigned int            prev_absx;
 104         unsigned int            prev_absy;
 105         unsigned char           bufferedmeasure;
 106 };
 107
 108 static void __iomem             *tsc_base;
 109
 110 #define atmel_tsadcc_read(reg)          __raw_readl(tsc_base + (reg))
 111 #define atmel_tsadcc_write(reg, val)    __raw_writel((val), tsc_base + (reg))
 112
 113 static irqreturn_t atmel_tsadcc_interrupt(int irq, void *dev)
 114 {
 115         struct atmel_tsadcc     *ts_dev = (struct atmel_tsadcc *)dev;
 116         struct input_dev        *input_dev = ts_dev->input;
 117
 118         unsigned int status;
 119         unsigned int reg;
 120
 121         status = atmel_tsadcc_read(ATMEL_TSADCC_SR);
 122         status &= atmel_tsadcc_read(ATMEL_TSADCC_IMR);
 123
 124         if (status & ATMEL_TSADCC_NOCNT) {
 125                 /* Contact lost */
 126                 reg = atmel_tsadcc_read(ATMEL_TSADCC_MR) | ATMEL_TSADCC_PENDBC;
 127
 128                 atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
 129                 atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE);
 130                 atmel_tsadcc_write(ATMEL_TSADCC_IDR,
 131                                    ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT);
 132                 atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT);
 133
 134                 input_report_key(input_dev, BTN_TOUCH, 0);
 135                 ts_dev->bufferedmeasure = 0;
 136                 input_sync(input_dev);
 137
 138         } else if (status & ATMEL_TSADCC_PENCNT) {
 139                 /* Pen detected */
 140                 reg = atmel_tsadcc_read(ATMEL_TSADCC_MR);
 141                 reg &= ~ATMEL_TSADCC_PENDBC;
 142
 143                 atmel_tsadcc_write(ATMEL_TSADCC_IDR, ATMEL_TSADCC_PENCNT);
 144                 atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
 145                 atmel_tsadcc_write(ATMEL_TSADCC_IER,
 146                                    ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT);
 147                 atmel_tsadcc_write(ATMEL_TSADCC_TRGR,
 148                                    ATMEL_TSADCC_TRGMOD_PERIOD | (0x0FFF << 16));
 149
 150         } else if (status & ATMEL_TSADCC_EOC(3)) {
 151                 /* Conversion finished */
 152
 153                 if (ts_dev->bufferedmeasure) {
 154                         /* Last measurement is always discarded, since it can
 155                          * be erroneous.
 156                          * Always report previous measurement */
 157                         input_report_abs(input_dev, ABS_X, ts_dev->prev_absx);
 158                         input_report_abs(input_dev, ABS_Y, ts_dev->prev_absy);
 159                         input_report_key(input_dev, BTN_TOUCH, 1);
 160                         input_sync(input_dev);
 161                 } else
 162                         ts_dev->bufferedmeasure = 1;
 163
 164                 /* Now make new measurement */
 165                 ts_dev->prev_absx = atmel_tsadcc_read(ATMEL_TSADCC_CDR3) << 10;
 166                 ts_dev->prev_absx /= atmel_tsadcc_read(ATMEL_TSADCC_CDR2);
 167
 168                 ts_dev->prev_absy = atmel_tsadcc_read(ATMEL_TSADCC_CDR1) << 10;
 169                 ts_dev->prev_absy /= atmel_tsadcc_read(ATMEL_TSADCC_CDR0);
 170         }
 171
 172         return IRQ_HANDLED;
 173 }
 174
 175 /*
 176  * The functions for inserting/removing us as a module.
 177  */
 178
 179 static int atmel_tsadcc_probe(struct platform_device *pdev)
 180 {
 181         struct atmel_tsadcc     *ts_dev;
 182         struct input_dev        *input_dev;
 183         struct resource         *res;
 184         struct at91_tsadcc_data *pdata = dev_get_platdata(&pdev->dev);
 185         int             err;
 186         unsigned int    prsc;
 187         unsigned int    reg;
 188
 189         if (!pdata)
 190                 return -EINVAL;
 191
 192         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 193         if (!res) {
 194                 dev_err(&pdev->dev, "no mmio resource defined.\n");
 195                 return -ENXIO;
 196         }
 197
 198         /* Allocate memory for device */
 199         ts_dev = kzalloc(sizeof(struct atmel_tsadcc), GFP_KERNEL);
 200         if (!ts_dev) {
 201                 dev_err(&pdev->dev, "failed to allocate memory.\n");
 202                 return -ENOMEM;
 203         }
 204         platform_set_drvdata(pdev, ts_dev);
 205
 206         input_dev = input_allocate_device();
 207         if (!input_dev) {
 208                 dev_err(&pdev->dev, "failed to allocate input device.\n");
 209                 err = -EBUSY;
 210                 goto err_free_mem;
 211         }
 212
 213         ts_dev->irq = platform_get_irq(pdev, 0);
 214         if (ts_dev->irq < 0) {
 215                 dev_err(&pdev->dev, "no irq ID is designated.\n");
 216                 err = -ENODEV;
 217                 goto err_free_dev;
 218         }
 219
 220         if (!request_mem_region(res->start, resource_size(res),
 221                                 "atmel tsadcc regs")) {
 222                 dev_err(&pdev->dev, "resources is unavailable.\n");
 223                 err = -EBUSY;
 224                 goto err_free_dev;
 225         }
 226
 227         tsc_base = ioremap(res->start, resource_size(res));
 228         if (!tsc_base) {
 229                 dev_err(&pdev->dev, "failed to map registers.\n");
 230                 err = -ENOMEM;
 231                 goto err_release_mem;
 232         }
 233
 234         err = request_irq(ts_dev->irq, atmel_tsadcc_interrupt, 0,
 235                         pdev->dev.driver->name, ts_dev);
 236         if (err) {
 237                 dev_err(&pdev->dev, "failed to allocate irq.\n");
 238                 goto err_unmap_regs;
 239         }
 240
 241         ts_dev->clk = clk_get(&pdev->dev, "tsc_clk");
 242         if (IS_ERR(ts_dev->clk)) {
 243                 dev_err(&pdev->dev, "failed to get ts_clk\n");
 244                 err = PTR_ERR(ts_dev->clk);
 245                 goto err_free_irq;
 246         }
 247
 248         ts_dev->input = input_dev;
 249         ts_dev->bufferedmeasure = 0;
 250
 251         snprintf(ts_dev->phys, sizeof(ts_dev->phys),
 252                  "%s/input0", dev_name(&pdev->dev));
 253
 254         input_dev->name = "atmel touch screen controller";
 255         input_dev->phys = ts_dev->phys;
 256         input_dev->dev.parent = &pdev->dev;
 257
 258         __set_bit(EV_ABS, input_dev->evbit);
 259         input_set_abs_params(input_dev, ABS_X, 0, 0x3FF, 0, 0);
 260         input_set_abs_params(input_dev, ABS_Y, 0, 0x3FF, 0, 0);
 261
 262         input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
 263
 264         /* clk_enable() always returns 0, no need to check it */
 265         clk_enable(ts_dev->clk);
 266
 267         prsc = clk_get_rate(ts_dev->clk);
 268         dev_info(&pdev->dev, "Master clock is set at: %d Hz\n", prsc);
 269
 270         if (!pdata->adc_clock)
 271                 pdata->adc_clock = ADC_DEFAULT_CLOCK;
 272
 273         prsc = (prsc / (2 * pdata->adc_clock)) - 1;
 274
 275         /* saturate if this value is too high */
 276         if (cpu_is_at91sam9rl()) {
 277                 if (prsc > PRESCALER_VAL(ATMEL_TSADCC_PRESCAL))
 278                         prsc = PRESCALER_VAL(ATMEL_TSADCC_PRESCAL);
 279         } else {
 280                 if (prsc > PRESCALER_VAL(ATMEL_TSADCC_EPRESCAL))
 281                         prsc = PRESCALER_VAL(ATMEL_TSADCC_EPRESCAL);
 282         }
 283
 284         dev_info(&pdev->dev, "Prescaler is set at: %d\n", prsc);
 285
 286         reg = ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE          |
 287                 ((0x00 << 5) & ATMEL_TSADCC_SLEEP)      |       /* Normal Mode */
 288                 ((0x01 << 6) & ATMEL_TSADCC_PENDET)     |       /* Enable Pen Detect */
 289                 (prsc << 8)                             |
 290                 ((0x26 << 16) & ATMEL_TSADCC_STARTUP)   |
 291                 ((pdata->pendet_debounce << 28) & ATMEL_TSADCC_PENDBC);
 292
 293         atmel_tsadcc_write(ATMEL_TSADCC_CR, ATMEL_TSADCC_SWRST);
 294         atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
 295         atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE);
 296         atmel_tsadcc_write(ATMEL_TSADCC_TSR,
 297                 (pdata->ts_sample_hold_time << 24) & ATMEL_TSADCC_TSSHTIM);
 298
 299         atmel_tsadcc_read(ATMEL_TSADCC_SR);
 300         atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT);
 301
 302         /* All went ok, so register to the input system */
 303         err = input_register_device(input_dev);
 304         if (err)
 305                 goto err_fail;
 306
 307         return 0;
 308
 309 err_fail:
 310         clk_disable(ts_dev->clk);
 311         clk_put(ts_dev->clk);
 312 err_free_irq:
 313         free_irq(ts_dev->irq, ts_dev);
 314 err_unmap_regs:
 315         iounmap(tsc_base);
 316 err_release_mem:
 317         release_mem_region(res->start, resource_size(res));
 318 err_free_dev:
 319         input_free_device(input_dev);
 320 err_free_mem:
 321         kfree(ts_dev);
 322         return err;
 323 }
 324
 325 static int atmel_tsadcc_remove(struct platform_device *pdev)
 326 {
 327         struct atmel_tsadcc *ts_dev = platform_get_drvdata(pdev);
 328         struct resource *res;
 329
 330         free_irq(ts_dev->irq, ts_dev);
 331
 332         input_unregister_device(ts_dev->input);
 333
 334         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 335         iounmap(tsc_base);
 336         release_mem_region(res->start, resource_size(res));
 337
 338         clk_disable(ts_dev->clk);
 339         clk_put(ts_dev->clk);
 340
 341         kfree(ts_dev);
 342
 343         return 0;
 344 }
 345
 346 static struct platform_driver atmel_tsadcc_driver = {
 347         .probe          = atmel_tsadcc_probe,
 348         .remove         = atmel_tsadcc_remove,
 349         .driver         = {
 350                 .name   = "atmel_tsadcc",
 351         },
 352 };
 353 module_platform_driver(atmel_tsadcc_driver);
 354
 355 MODULE_LICENSE("GPL");
 356 MODULE_DESCRIPTION("Atmel TouchScreen Driver");
 357 MODULE_AUTHOR("Dan Liang <dan.liang@atmel.com>");
 358