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/init.h>
  16 #include <linux/err.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/input.h>
  20 #include <linux/slab.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/clk.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/io.h>
  25
  26 /* Register definitions based on AT91SAM9RL64 preliminary draft datasheet */
  27
  28 #define ATMEL_TSADCC_CR         0x00    /* Control register */
  29 #define   ATMEL_TSADCC_SWRST    (1 << 0)        /* Software Reset*/
  30 #define   ATMEL_TSADCC_START    (1 << 1)        /* Start conversion */
  31
  32 #define ATMEL_TSADCC_MR         0x04    /* Mode register */
  33 #define   ATMEL_TSADCC_TSAMOD   (3    <<  0)    /* ADC mode */
  34 #define     ATMEL_TSADCC_TSAMOD_ADC_ONLY_MODE   (0x0)   /* ADC Mode */
  35 #define     ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE    (0x1)   /* Touch Screen Only Mode */
  36 #define   ATMEL_TSADCC_LOWRES   (1    <<  4)    /* Resolution selection */
  37 #define   ATMEL_TSADCC_SLEEP    (1    <<  5)    /* Sleep mode */
  38 #define   ATMEL_TSADCC_PENDET   (1    <<  6)    /* Pen Detect selection */
  39 #define   ATMEL_TSADCC_PRESCAL  (0x3f <<  8)    /* Prescalar Rate Selection */
  40 #define   ATMEL_TSADCC_STARTUP  (0x7f << 16)    /* Start Up time */
  41 #define   ATMEL_TSADCC_SHTIM    (0xf  << 24)    /* Sample & Hold time */
  42 #define   ATMEL_TSADCC_PENDBC   (0xf  << 28)    /* Pen Detect debouncing time */
  43
  44 #define ATMEL_TSADCC_TRGR       0x08    /* Trigger register */
  45 #define   ATMEL_TSADCC_TRGMOD   (7      <<  0)  /* Trigger mode */
  46 #define     ATMEL_TSADCC_TRGMOD_NONE            (0 << 0)
  47 #define     ATMEL_TSADCC_TRGMOD_EXT_RISING      (1 << 0)
  48 #define     ATMEL_TSADCC_TRGMOD_EXT_FALLING     (2 << 0)
  49 #define     ATMEL_TSADCC_TRGMOD_EXT_ANY         (3 << 0)
  50 #define     ATMEL_TSADCC_TRGMOD_PENDET          (4 << 0)
  51 #define     ATMEL_TSADCC_TRGMOD_PERIOD          (5 << 0)
  52 #define     ATMEL_TSADCC_TRGMOD_CONTINUOUS      (6 << 0)
  53 #define   ATMEL_TSADCC_TRGPER   (0xffff << 16)  /* Trigger period */
  54
  55 #define ATMEL_TSADCC_TSR        0x0C    /* Touch Screen register */
  56 #define   ATMEL_TSADCC_TSFREQ   (0xf <<  0)     /* TS Frequency in Interleaved mode */
  57 #define   ATMEL_TSADCC_TSSHTIM  (0xf << 24)     /* Sample & Hold time */
  58
  59 #define ATMEL_TSADCC_CHER       0x10    /* Channel Enable register */
  60 #define ATMEL_TSADCC_CHDR       0x14    /* Channel Disable register */
  61 #define ATMEL_TSADCC_CHSR       0x18    /* Channel Status register */
  62 #define   ATMEL_TSADCC_CH(n)    (1 << (n))      /* Channel number */
  63
  64 #define ATMEL_TSADCC_SR         0x1C    /* Status register */
  65 #define   ATMEL_TSADCC_EOC(n)   (1 << ((n)+0))  /* End of conversion for channel N */
  66 #define   ATMEL_TSADCC_OVRE(n)  (1 << ((n)+8))  /* Overrun error for channel N */
  67 #define   ATMEL_TSADCC_DRDY     (1 << 16)       /* Data Ready */
  68 #define   ATMEL_TSADCC_GOVRE    (1 << 17)       /* General Overrun Error */
  69 #define   ATMEL_TSADCC_ENDRX    (1 << 18)       /* End of RX Buffer */
  70 #define   ATMEL_TSADCC_RXBUFF   (1 << 19)       /* TX Buffer full */
  71 #define   ATMEL_TSADCC_PENCNT   (1 << 20)       /* Pen contact */
  72 #define   ATMEL_TSADCC_NOCNT    (1 << 21)       /* No contact */
  73
  74 #define ATMEL_TSADCC_LCDR       0x20    /* Last Converted Data register */
  75 #define   ATMEL_TSADCC_DATA     (0x3ff << 0)    /* Channel data */
  76
  77 #define ATMEL_TSADCC_IER        0x24    /* Interrupt Enable register */
  78 #define ATMEL_TSADCC_IDR        0x28    /* Interrupt Disable register */
  79 #define ATMEL_TSADCC_IMR        0x2C    /* Interrupt Mask register */
  80 #define ATMEL_TSADCC_CDR0       0x30    /* Channel Data 0 */
  81 #define ATMEL_TSADCC_CDR1       0x34    /* Channel Data 1 */
  82 #define ATMEL_TSADCC_CDR2       0x38    /* Channel Data 2 */
  83 #define ATMEL_TSADCC_CDR3       0x3C    /* Channel Data 3 */
  84 #define ATMEL_TSADCC_CDR4       0x40    /* Channel Data 4 */
  85 #define ATMEL_TSADCC_CDR5       0x44    /* Channel Data 5 */
  86
  87 #define ADC_CLOCK       1000000
  88
  89 struct atmel_tsadcc {
  90         struct input_dev        *input;
  91         char                    phys[32];
  92         struct clk              *clk;
  93         int                     irq;
  94         unsigned int            prev_absx;
  95         unsigned int            prev_absy;
  96         unsigned char           bufferedmeasure;
  97 };
  98
  99 static void __iomem             *tsc_base;
 100
 101 #define atmel_tsadcc_read(reg)          __raw_readl(tsc_base + (reg))
 102 #define atmel_tsadcc_write(reg, val)    __raw_writel((val), tsc_base + (reg))
 103
 104 static irqreturn_t atmel_tsadcc_interrupt(int irq, void *dev)
 105 {
 106         struct atmel_tsadcc     *ts_dev = (struct atmel_tsadcc *)dev;
 107         struct input_dev        *input_dev = ts_dev->input;
 108
 109         unsigned int status;
 110         unsigned int reg;
 111
 112         status = atmel_tsadcc_read(ATMEL_TSADCC_SR);
 113         status &= atmel_tsadcc_read(ATMEL_TSADCC_IMR);
 114
 115         if (status & ATMEL_TSADCC_NOCNT) {
 116                 /* Contact lost */
 117                 reg = atmel_tsadcc_read(ATMEL_TSADCC_MR) | ATMEL_TSADCC_PENDBC;
 118
 119                 atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
 120                 atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE);
 121                 atmel_tsadcc_write(ATMEL_TSADCC_IDR,
 122                                    ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT);
 123                 atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT);
 124
 125                 input_report_key(input_dev, BTN_TOUCH, 0);
 126                 ts_dev->bufferedmeasure = 0;
 127                 input_sync(input_dev);
 128
 129         } else if (status & ATMEL_TSADCC_PENCNT) {
 130                 /* Pen detected */
 131                 reg = atmel_tsadcc_read(ATMEL_TSADCC_MR);
 132                 reg &= ~ATMEL_TSADCC_PENDBC;
 133
 134                 atmel_tsadcc_write(ATMEL_TSADCC_IDR, ATMEL_TSADCC_PENCNT);
 135                 atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
 136                 atmel_tsadcc_write(ATMEL_TSADCC_IER,
 137                                    ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT);
 138                 atmel_tsadcc_write(ATMEL_TSADCC_TRGR,
 139                                    ATMEL_TSADCC_TRGMOD_PERIOD | (0x0FFF << 16));
 140
 141         } else if (status & ATMEL_TSADCC_EOC(3)) {
 142                 /* Conversion finished */
 143
 144                 if (ts_dev->bufferedmeasure) {
 145                         /* Last measurement is always discarded, since it can
 146                          * be erroneous.
 147                          * Always report previous measurement */
 148                         input_report_abs(input_dev, ABS_X, ts_dev->prev_absx);
 149                         input_report_abs(input_dev, ABS_Y, ts_dev->prev_absy);
 150                         input_report_key(input_dev, BTN_TOUCH, 1);
 151                         input_sync(input_dev);
 152                 } else
 153                         ts_dev->bufferedmeasure = 1;
 154
 155                 /* Now make new measurement */
 156                 ts_dev->prev_absx = atmel_tsadcc_read(ATMEL_TSADCC_CDR3) << 10;
 157                 ts_dev->prev_absx /= atmel_tsadcc_read(ATMEL_TSADCC_CDR2);
 158
 159                 ts_dev->prev_absy = atmel_tsadcc_read(ATMEL_TSADCC_CDR1) << 10;
 160                 ts_dev->prev_absy /= atmel_tsadcc_read(ATMEL_TSADCC_CDR0);
 161         }
 162
 163         return IRQ_HANDLED;
 164 }
 165
 166 /*
 167  * The functions for inserting/removing us as a module.
 168  */
 169
 170 static int __devinit atmel_tsadcc_probe(struct platform_device *pdev)
 171 {
 172         struct atmel_tsadcc     *ts_dev;
 173         struct input_dev        *input_dev;
 174         struct resource         *res;
 175         int             err = 0;
 176         unsigned int    prsc;
 177         unsigned int    reg;
 178
 179         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 180         if (!res) {
 181                 dev_err(&pdev->dev, "no mmio resource defined.\n");
 182                 return -ENXIO;
 183         }
 184
 185         /* Allocate memory for device */
 186         ts_dev = kzalloc(sizeof(struct atmel_tsadcc), GFP_KERNEL);
 187         if (!ts_dev) {
 188                 dev_err(&pdev->dev, "failed to allocate memory.\n");
 189                 return -ENOMEM;
 190         }
 191         platform_set_drvdata(pdev, ts_dev);
 192
 193         input_dev = input_allocate_device();
 194         if (!input_dev) {
 195                 dev_err(&pdev->dev, "failed to allocate input device.\n");
 196                 err = -EBUSY;
 197                 goto err_free_mem;
 198         }
 199
 200         ts_dev->irq = platform_get_irq(pdev, 0);
 201         if (ts_dev->irq < 0) {
 202                 dev_err(&pdev->dev, "no irq ID is designated.\n");
 203                 err = -ENODEV;
 204                 goto err_free_dev;
 205         }
 206
 207         if (!request_mem_region(res->start, resource_size(res),
 208                                 "atmel tsadcc regs")) {
 209                 dev_err(&pdev->dev, "resources is unavailable.\n");
 210                 err = -EBUSY;
 211                 goto err_free_dev;
 212         }
 213
 214         tsc_base = ioremap(res->start, resource_size(res));
 215         if (!tsc_base) {
 216                 dev_err(&pdev->dev, "failed to map registers.\n");
 217                 err = -ENOMEM;
 218                 goto err_release_mem;
 219         }
 220
 221         err = request_irq(ts_dev->irq, atmel_tsadcc_interrupt, IRQF_DISABLED,
 222                         pdev->dev.driver->name, ts_dev);
 223         if (err) {
 224                 dev_err(&pdev->dev, "failed to allocate irq.\n");
 225                 goto err_unmap_regs;
 226         }
 227
 228         ts_dev->clk = clk_get(&pdev->dev, "tsc_clk");
 229         if (IS_ERR(ts_dev->clk)) {
 230                 dev_err(&pdev->dev, "failed to get ts_clk\n");
 231                 err = PTR_ERR(ts_dev->clk);
 232                 goto err_free_irq;
 233         }
 234
 235         ts_dev->input = input_dev;
 236         ts_dev->bufferedmeasure = 0;
 237
 238         snprintf(ts_dev->phys, sizeof(ts_dev->phys),
 239                  "%s/input0", dev_name(&pdev->dev));
 240
 241         input_dev->name = "atmel touch screen controller";
 242         input_dev->phys = ts_dev->phys;
 243         input_dev->dev.parent = &pdev->dev;
 244
 245         __set_bit(EV_ABS, input_dev->evbit);
 246         input_set_abs_params(input_dev, ABS_X, 0, 0x3FF, 0, 0);
 247         input_set_abs_params(input_dev, ABS_Y, 0, 0x3FF, 0, 0);
 248
 249         input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
 250
 251         /* clk_enable() always returns 0, no need to check it */
 252         clk_enable(ts_dev->clk);
 253
 254         prsc = clk_get_rate(ts_dev->clk);
 255         dev_info(&pdev->dev, "Master clock is set at: %d Hz\n", prsc);
 256
 257         prsc = prsc / ADC_CLOCK / 2 - 1;
 258
 259         reg = ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE          |
 260                 ((0x00 << 5) & ATMEL_TSADCC_SLEEP)      |       /* Normal Mode */
 261                 ((0x01 << 6) & ATMEL_TSADCC_PENDET)     |       /* Enable Pen Detect */
 262                 ((prsc << 8) & ATMEL_TSADCC_PRESCAL)    |       /* PRESCAL */
 263                 ((0x13 << 16) & ATMEL_TSADCC_STARTUP)   |       /* STARTUP */
 264                 ((0x0F << 28) & ATMEL_TSADCC_PENDBC);           /* PENDBC */
 265
 266         atmel_tsadcc_write(ATMEL_TSADCC_CR, ATMEL_TSADCC_SWRST);
 267         atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
 268         atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE);
 269         atmel_tsadcc_write(ATMEL_TSADCC_TSR, (0x3 << 24) & ATMEL_TSADCC_TSSHTIM);
 270
 271         atmel_tsadcc_read(ATMEL_TSADCC_SR);
 272         atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT);
 273
 274         /* All went ok, so register to the input system */
 275         err = input_register_device(input_dev);
 276         if (err)
 277                 goto err_fail;
 278
 279         return 0;
 280
 281 err_fail:
 282         clk_disable(ts_dev->clk);
 283         clk_put(ts_dev->clk);
 284 err_free_irq:
 285         free_irq(ts_dev->irq, ts_dev);
 286 err_unmap_regs:
 287         iounmap(tsc_base);
 288 err_release_mem:
 289         release_mem_region(res->start, resource_size(res));
 290 err_free_dev:
 291         input_free_device(ts_dev->input);
 292 err_free_mem:
 293         kfree(ts_dev);
 294         return err;
 295 }
 296
 297 static int __devexit atmel_tsadcc_remove(struct platform_device *pdev)
 298 {
 299         struct atmel_tsadcc *ts_dev = dev_get_drvdata(&pdev->dev);
 300         struct resource *res;
 301
 302         free_irq(ts_dev->irq, ts_dev);
 303
 304         input_unregister_device(ts_dev->input);
 305
 306         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 307         iounmap(tsc_base);
 308         release_mem_region(res->start, resource_size(res));
 309
 310         clk_disable(ts_dev->clk);
 311         clk_put(ts_dev->clk);
 312
 313         kfree(ts_dev);
 314
 315         return 0;
 316 }
 317
 318 static struct platform_driver atmel_tsadcc_driver = {
 319         .probe          = atmel_tsadcc_probe,
 320         .remove         = __devexit_p(atmel_tsadcc_remove),
 321         .driver         = {
 322                 .name   = "atmel_tsadcc",
 323         },
 324 };
 325
 326 static int __init atmel_tsadcc_init(void)
 327 {
 328         return platform_driver_register(&atmel_tsadcc_driver);
 329 }
 330
 331 static void __exit atmel_tsadcc_exit(void)
 332 {
 333         platform_driver_unregister(&atmel_tsadcc_driver);
 334 }
 335
 336 module_init(atmel_tsadcc_init);
 337 module_exit(atmel_tsadcc_exit);
 338
 339
 340 MODULE_LICENSE("GPL");
 341 MODULE_DESCRIPTION("Atmel TouchScreen Driver");
 342 MODULE_AUTHOR("Dan Liang <dan.liang@atmel.com>");
 343