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