drivers/input/touchscreen/w90p910_ts.c

   1 /*
   2  * Copyright (c) 2008 Nuvoton technology corporation.
   3  *
   4  * Wan ZongShun <mcuos.com@gmail.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation;version 2 of the License.
   9  *
  10  */
  11
  12 #include <linux/delay.h>
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/io.h>
  16 #include <linux/clk.h>
  17 #include <linux/input.h>
  18 #include <linux/interrupt.h>
  19
  20 /* ADC controller bit defines */
  21 #define ADC_DELAY       0xf00
  22 #define ADC_DOWN        0x01
  23 #define ADC_TSC_Y       (0x01 << 8)
  24 #define ADC_TSC_X       (0x00 << 8)
  25 #define TSC_FOURWIRE    (~(0x03 << 1))
  26 #define ADC_CLK_EN      (0x01 << 28)    /* ADC clock enable */
  27 #define ADC_READ_CON    (0x01 << 12)
  28 #define ADC_CONV        (0x01 << 13)
  29 #define ADC_SEMIAUTO    (0x01 << 14)
  30 #define ADC_WAITTRIG    (0x03 << 14)
  31 #define ADC_RST1        (0x01 << 16)
  32 #define ADC_RST0        (0x00 << 16)
  33 #define ADC_EN          (0x01 << 17)
  34 #define ADC_INT         (0x01 << 18)
  35 #define WT_INT          (0x01 << 20)
  36 #define ADC_INT_EN      (0x01 << 21)
  37 #define LVD_INT_EN      (0x01 << 22)
  38 #define WT_INT_EN       (0x01 << 23)
  39 #define ADC_DIV         (0x04 << 1)     /* div = 6 */
  40
  41 enum ts_state {
  42         TS_WAIT_NEW_PACKET,     /* We are waiting next touch report */
  43         TS_WAIT_X_COORD,        /* We are waiting for ADC to report X coord */
  44         TS_WAIT_Y_COORD,        /* We are waiting for ADC to report Y coord */
  45         TS_IDLE,                /* Input device is closed, don't do anything */
  46 };
  47
  48 struct w90p910_ts {
  49         struct input_dev *input;
  50         struct timer_list timer;
  51         struct clk *clk;
  52         int irq_num;
  53         void __iomem *ts_reg;
  54         spinlock_t lock;
  55         enum ts_state state;
  56 };
  57
  58 static void w90p910_report_event(struct w90p910_ts *w90p910_ts, bool down)
  59 {
  60         struct input_dev *dev = w90p910_ts->input;
  61
  62         if (down) {
  63                 input_report_abs(dev, ABS_X,
  64                                  __raw_readl(w90p910_ts->ts_reg + 0x0c));
  65                 input_report_abs(dev, ABS_Y,
  66                                  __raw_readl(w90p910_ts->ts_reg + 0x10));
  67         }
  68
  69         input_report_key(dev, BTN_TOUCH, down);
  70         input_sync(dev);
  71 }
  72
  73 static void w90p910_prepare_x_reading(struct w90p910_ts *w90p910_ts)
  74 {
  75         unsigned long ctlreg;
  76
  77         __raw_writel(ADC_TSC_X, w90p910_ts->ts_reg + 0x04);
  78         ctlreg = __raw_readl(w90p910_ts->ts_reg);
  79         ctlreg &= ~(ADC_WAITTRIG | WT_INT | WT_INT_EN);
  80         ctlreg |= ADC_SEMIAUTO | ADC_INT_EN | ADC_CONV;
  81         __raw_writel(ctlreg, w90p910_ts->ts_reg);
  82
  83         w90p910_ts->state = TS_WAIT_X_COORD;
  84 }
  85
  86 static void w90p910_prepare_y_reading(struct w90p910_ts *w90p910_ts)
  87 {
  88         unsigned long ctlreg;
  89
  90         __raw_writel(ADC_TSC_Y, w90p910_ts->ts_reg + 0x04);
  91         ctlreg = __raw_readl(w90p910_ts->ts_reg);
  92         ctlreg &= ~(ADC_WAITTRIG | ADC_INT | WT_INT_EN);
  93         ctlreg |= ADC_SEMIAUTO | ADC_INT_EN | ADC_CONV;
  94         __raw_writel(ctlreg, w90p910_ts->ts_reg);
  95
  96         w90p910_ts->state = TS_WAIT_Y_COORD;
  97 }
  98
  99 static void w90p910_prepare_next_packet(struct w90p910_ts *w90p910_ts)
 100 {
 101         unsigned long ctlreg;
 102
 103         ctlreg = __raw_readl(w90p910_ts->ts_reg);
 104         ctlreg &= ~(ADC_INT | ADC_INT_EN | ADC_SEMIAUTO | ADC_CONV);
 105         ctlreg |= ADC_WAITTRIG | WT_INT_EN;
 106         __raw_writel(ctlreg, w90p910_ts->ts_reg);
 107
 108         w90p910_ts->state = TS_WAIT_NEW_PACKET;
 109 }
 110
 111 static irqreturn_t w90p910_ts_interrupt(int irq, void *dev_id)
 112 {
 113         struct w90p910_ts *w90p910_ts = dev_id;
 114         unsigned long flags;
 115
 116         spin_lock_irqsave(&w90p910_ts->lock, flags);
 117
 118         switch (w90p910_ts->state) {
 119         case TS_WAIT_NEW_PACKET:
 120                 /*
 121                  * The controller only generates interrupts when pen
 122                  * is down.
 123                  */
 124                 del_timer(&w90p910_ts->timer);
 125                 w90p910_prepare_x_reading(w90p910_ts);
 126                 break;
 127
 128
 129         case TS_WAIT_X_COORD:
 130                 w90p910_prepare_y_reading(w90p910_ts);
 131                 break;
 132
 133         case TS_WAIT_Y_COORD:
 134                 w90p910_report_event(w90p910_ts, true);
 135                 w90p910_prepare_next_packet(w90p910_ts);
 136                 mod_timer(&w90p910_ts->timer, jiffies + msecs_to_jiffies(100));
 137                 break;
 138
 139         case TS_IDLE:
 140                 break;
 141         }
 142
 143         spin_unlock_irqrestore(&w90p910_ts->lock, flags);
 144
 145         return IRQ_HANDLED;
 146 }
 147
 148 static void w90p910_check_pen_up(unsigned long data)
 149 {
 150         struct w90p910_ts *w90p910_ts = (struct w90p910_ts *) data;
 151         unsigned long flags;
 152
 153         spin_lock_irqsave(&w90p910_ts->lock, flags);
 154
 155         if (w90p910_ts->state == TS_WAIT_NEW_PACKET &&
 156             !(__raw_readl(w90p910_ts->ts_reg + 0x04) & ADC_DOWN)) {
 157
 158                 w90p910_report_event(w90p910_ts, false);
 159         }
 160
 161         spin_unlock_irqrestore(&w90p910_ts->lock, flags);
 162 }
 163
 164 static int w90p910_open(struct input_dev *dev)
 165 {
 166         struct w90p910_ts *w90p910_ts = input_get_drvdata(dev);
 167         unsigned long val;
 168
 169         /* enable the ADC clock */
 170         clk_enable(w90p910_ts->clk);
 171
 172         __raw_writel(ADC_RST1, w90p910_ts->ts_reg);
 173         msleep(1);
 174         __raw_writel(ADC_RST0, w90p910_ts->ts_reg);
 175         msleep(1);
 176
 177         /* set delay and screen type */
 178         val = __raw_readl(w90p910_ts->ts_reg + 0x04);
 179         __raw_writel(val & TSC_FOURWIRE, w90p910_ts->ts_reg + 0x04);
 180         __raw_writel(ADC_DELAY, w90p910_ts->ts_reg + 0x08);
 181
 182         w90p910_ts->state = TS_WAIT_NEW_PACKET;
 183         wmb();
 184
 185         /* set trigger mode */
 186         val = __raw_readl(w90p910_ts->ts_reg);
 187         val |= ADC_WAITTRIG | ADC_DIV | ADC_EN | WT_INT_EN;
 188         __raw_writel(val, w90p910_ts->ts_reg);
 189
 190         return 0;
 191 }
 192
 193 static void w90p910_close(struct input_dev *dev)
 194 {
 195         struct w90p910_ts *w90p910_ts = input_get_drvdata(dev);
 196         unsigned long val;
 197
 198         /* disable trigger mode */
 199
 200         spin_lock_irq(&w90p910_ts->lock);
 201
 202         w90p910_ts->state = TS_IDLE;
 203
 204         val = __raw_readl(w90p910_ts->ts_reg);
 205         val &= ~(ADC_WAITTRIG | ADC_DIV | ADC_EN | WT_INT_EN | ADC_INT_EN);
 206         __raw_writel(val, w90p910_ts->ts_reg);
 207
 208         spin_unlock_irq(&w90p910_ts->lock);
 209
 210         /* Now that interrupts are shut off we can safely delete timer */
 211         del_timer_sync(&w90p910_ts->timer);
 212
 213         /* stop the ADC clock */
 214         clk_disable(w90p910_ts->clk);
 215 }
 216
 217 static int __devinit w90x900ts_probe(struct platform_device *pdev)
 218 {
 219         struct w90p910_ts *w90p910_ts;
 220         struct input_dev *input_dev;
 221         struct resource *res;
 222         int err;
 223
 224         w90p910_ts = kzalloc(sizeof(struct w90p910_ts), GFP_KERNEL);
 225         input_dev = input_allocate_device();
 226         if (!w90p910_ts || !input_dev) {
 227                 err = -ENOMEM;
 228                 goto fail1;
 229         }
 230
 231         w90p910_ts->input = input_dev;
 232         w90p910_ts->state = TS_IDLE;
 233         spin_lock_init(&w90p910_ts->lock);
 234         setup_timer(&w90p910_ts->timer, w90p910_check_pen_up,
 235                     (unsigned long)&w90p910_ts);
 236
 237         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 238         if (!res) {
 239                 err = -ENXIO;
 240                 goto fail1;
 241         }
 242
 243         if (!request_mem_region(res->start, resource_size(res),
 244                                 pdev->name)) {
 245                 err = -EBUSY;
 246                 goto fail1;
 247         }
 248
 249         w90p910_ts->ts_reg = ioremap(res->start, resource_size(res));
 250         if (!w90p910_ts->ts_reg) {
 251                 err = -ENOMEM;
 252                 goto fail2;
 253         }
 254
 255         w90p910_ts->clk = clk_get(&pdev->dev, NULL);
 256         if (IS_ERR(w90p910_ts->clk)) {
 257                 err = PTR_ERR(w90p910_ts->clk);
 258                 goto fail3;
 259         }
 260
 261         input_dev->name = "W90P910 TouchScreen";
 262         input_dev->phys = "w90p910ts/event0";
 263         input_dev->id.bustype = BUS_HOST;
 264         input_dev->id.vendor  = 0x0005;
 265         input_dev->id.product = 0x0001;
 266         input_dev->id.version = 0x0100;
 267         input_dev->dev.parent = &pdev->dev;
 268         input_dev->open = w90p910_open;
 269         input_dev->close = w90p910_close;
 270
 271         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 272         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 273
 274         input_set_abs_params(input_dev, ABS_X, 0, 0x400, 0, 0);
 275         input_set_abs_params(input_dev, ABS_Y, 0, 0x400, 0, 0);
 276
 277         input_set_drvdata(input_dev, w90p910_ts);
 278
 279         w90p910_ts->irq_num = platform_get_irq(pdev, 0);
 280         if (request_irq(w90p910_ts->irq_num, w90p910_ts_interrupt,
 281                         IRQF_DISABLED, "w90p910ts", w90p910_ts)) {
 282                 err = -EBUSY;
 283                 goto fail4;
 284         }
 285
 286         err = input_register_device(w90p910_ts->input);
 287         if (err)
 288                 goto fail5;
 289
 290         platform_set_drvdata(pdev, w90p910_ts);
 291
 292         return 0;
 293
 294 fail5:  free_irq(w90p910_ts->irq_num, w90p910_ts);
 295 fail4:  clk_put(w90p910_ts->clk);
 296 fail3:  iounmap(w90p910_ts->ts_reg);
 297 fail2:  release_mem_region(res->start, resource_size(res));
 298 fail1:  input_free_device(input_dev);
 299         kfree(w90p910_ts);
 300         return err;
 301 }
 302
 303 static int __devexit w90x900ts_remove(struct platform_device *pdev)
 304 {
 305         struct w90p910_ts *w90p910_ts = platform_get_drvdata(pdev);
 306         struct resource *res;
 307
 308         free_irq(w90p910_ts->irq_num, w90p910_ts);
 309         del_timer_sync(&w90p910_ts->timer);
 310         iounmap(w90p910_ts->ts_reg);
 311
 312         clk_put(w90p910_ts->clk);
 313
 314         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 315         release_mem_region(res->start, resource_size(res));
 316
 317         input_unregister_device(w90p910_ts->input);
 318         kfree(w90p910_ts);
 319
 320         platform_set_drvdata(pdev, NULL);
 321
 322         return 0;
 323 }
 324
 325 static struct platform_driver w90x900ts_driver = {
 326         .probe          = w90x900ts_probe,
 327         .remove         = __devexit_p(w90x900ts_remove),
 328         .driver         = {
 329                 .name   = "nuc900-ts",
 330                 .owner  = THIS_MODULE,
 331         },
 332 };
 333
 334 static int __init w90x900ts_init(void)
 335 {
 336         return platform_driver_register(&w90x900ts_driver);
 337 }
 338
 339 static void __exit w90x900ts_exit(void)
 340 {
 341         platform_driver_unregister(&w90x900ts_driver);
 342 }
 343
 344 module_init(w90x900ts_init);
 345 module_exit(w90x900ts_exit);
 346
 347 MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
 348 MODULE_DESCRIPTION("w90p910 touch screen driver!");
 349 MODULE_LICENSE("GPL");
 350 MODULE_ALIAS("platform:nuc900-ts");