drivers/input/touchscreen/w90p910_ts.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2008 Nuvoton technology corporation.
   4  *
   5  * Wan ZongShun <mcuos.com@gmail.com>
   6  */
   7
   8 #include <linux/delay.h>
   9 #include <linux/module.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/io.h>
  12 #include <linux/clk.h>
  13 #include <linux/input.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/slab.h>
  16
  17 /* ADC controller bit defines */
  18 #define ADC_DELAY       0xf00
  19 #define ADC_DOWN        0x01
  20 #define ADC_TSC_Y       (0x01 << 8)
  21 #define ADC_TSC_X       (0x00 << 8)
  22 #define TSC_FOURWIRE    (~(0x03 << 1))
  23 #define ADC_CLK_EN      (0x01 << 28)    /* ADC clock enable */
  24 #define ADC_READ_CON    (0x01 << 12)
  25 #define ADC_CONV        (0x01 << 13)
  26 #define ADC_SEMIAUTO    (0x01 << 14)
  27 #define ADC_WAITTRIG    (0x03 << 14)
  28 #define ADC_RST1        (0x01 << 16)
  29 #define ADC_RST0        (0x00 << 16)
  30 #define ADC_EN          (0x01 << 17)
  31 #define ADC_INT         (0x01 << 18)
  32 #define WT_INT          (0x01 << 20)
  33 #define ADC_INT_EN      (0x01 << 21)
  34 #define LVD_INT_EN      (0x01 << 22)
  35 #define WT_INT_EN       (0x01 << 23)
  36 #define ADC_DIV         (0x04 << 1)     /* div = 6 */
  37
  38 enum ts_state {
  39         TS_WAIT_NEW_PACKET,     /* We are waiting next touch report */
  40         TS_WAIT_X_COORD,        /* We are waiting for ADC to report X coord */
  41         TS_WAIT_Y_COORD,        /* We are waiting for ADC to report Y coord */
  42         TS_IDLE,                /* Input device is closed, don't do anything */
  43 };
  44
  45 struct w90p910_ts {
  46         struct input_dev *input;
  47         struct timer_list timer;
  48         struct clk *clk;
  49         int irq_num;
  50         void __iomem *ts_reg;
  51         spinlock_t lock;
  52         enum ts_state state;
  53 };
  54
  55 static void w90p910_report_event(struct w90p910_ts *w90p910_ts, bool down)
  56 {
  57         struct input_dev *dev = w90p910_ts->input;
  58
  59         if (down) {
  60                 input_report_abs(dev, ABS_X,
  61                                  __raw_readl(w90p910_ts->ts_reg + 0x0c));
  62                 input_report_abs(dev, ABS_Y,
  63                                  __raw_readl(w90p910_ts->ts_reg + 0x10));
  64         }
  65
  66         input_report_key(dev, BTN_TOUCH, down);
  67         input_sync(dev);
  68 }
  69
  70 static void w90p910_prepare_x_reading(struct w90p910_ts *w90p910_ts)
  71 {
  72         unsigned long ctlreg;
  73
  74         __raw_writel(ADC_TSC_X, w90p910_ts->ts_reg + 0x04);
  75         ctlreg = __raw_readl(w90p910_ts->ts_reg);
  76         ctlreg &= ~(ADC_WAITTRIG | WT_INT | WT_INT_EN);
  77         ctlreg |= ADC_SEMIAUTO | ADC_INT_EN | ADC_CONV;
  78         __raw_writel(ctlreg, w90p910_ts->ts_reg);
  79
  80         w90p910_ts->state = TS_WAIT_X_COORD;
  81 }
  82
  83 static void w90p910_prepare_y_reading(struct w90p910_ts *w90p910_ts)
  84 {
  85         unsigned long ctlreg;
  86
  87         __raw_writel(ADC_TSC_Y, w90p910_ts->ts_reg + 0x04);
  88         ctlreg = __raw_readl(w90p910_ts->ts_reg);
  89         ctlreg &= ~(ADC_WAITTRIG | ADC_INT | WT_INT_EN);
  90         ctlreg |= ADC_SEMIAUTO | ADC_INT_EN | ADC_CONV;
  91         __raw_writel(ctlreg, w90p910_ts->ts_reg);
  92
  93         w90p910_ts->state = TS_WAIT_Y_COORD;
  94 }
  95
  96 static void w90p910_prepare_next_packet(struct w90p910_ts *w90p910_ts)
  97 {
  98         unsigned long ctlreg;
  99
 100         ctlreg = __raw_readl(w90p910_ts->ts_reg);
 101         ctlreg &= ~(ADC_INT | ADC_INT_EN | ADC_SEMIAUTO | ADC_CONV);
 102         ctlreg |= ADC_WAITTRIG | WT_INT_EN;
 103         __raw_writel(ctlreg, w90p910_ts->ts_reg);
 104
 105         w90p910_ts->state = TS_WAIT_NEW_PACKET;
 106 }
 107
 108 static irqreturn_t w90p910_ts_interrupt(int irq, void *dev_id)
 109 {
 110         struct w90p910_ts *w90p910_ts = dev_id;
 111         unsigned long flags;
 112
 113         spin_lock_irqsave(&w90p910_ts->lock, flags);
 114
 115         switch (w90p910_ts->state) {
 116         case TS_WAIT_NEW_PACKET:
 117                 /*
 118                  * The controller only generates interrupts when pen
 119                  * is down.
 120                  */
 121                 del_timer(&w90p910_ts->timer);
 122                 w90p910_prepare_x_reading(w90p910_ts);
 123                 break;
 124
 125
 126         case TS_WAIT_X_COORD:
 127                 w90p910_prepare_y_reading(w90p910_ts);
 128                 break;
 129
 130         case TS_WAIT_Y_COORD:
 131                 w90p910_report_event(w90p910_ts, true);
 132                 w90p910_prepare_next_packet(w90p910_ts);
 133                 mod_timer(&w90p910_ts->timer, jiffies + msecs_to_jiffies(100));
 134                 break;
 135
 136         case TS_IDLE:
 137                 break;
 138         }
 139
 140         spin_unlock_irqrestore(&w90p910_ts->lock, flags);
 141
 142         return IRQ_HANDLED;
 143 }
 144
 145 static void w90p910_check_pen_up(struct timer_list *t)
 146 {
 147         struct w90p910_ts *w90p910_ts = from_timer(w90p910_ts, t, timer);
 148         unsigned long flags;
 149
 150         spin_lock_irqsave(&w90p910_ts->lock, flags);
 151
 152         if (w90p910_ts->state == TS_WAIT_NEW_PACKET &&
 153             !(__raw_readl(w90p910_ts->ts_reg + 0x04) & ADC_DOWN)) {
 154
 155                 w90p910_report_event(w90p910_ts, false);
 156         }
 157
 158         spin_unlock_irqrestore(&w90p910_ts->lock, flags);
 159 }
 160
 161 static int w90p910_open(struct input_dev *dev)
 162 {
 163         struct w90p910_ts *w90p910_ts = input_get_drvdata(dev);
 164         unsigned long val;
 165
 166         /* enable the ADC clock */
 167         clk_enable(w90p910_ts->clk);
 168
 169         __raw_writel(ADC_RST1, w90p910_ts->ts_reg);
 170         msleep(1);
 171         __raw_writel(ADC_RST0, w90p910_ts->ts_reg);
 172         msleep(1);
 173
 174         /* set delay and screen type */
 175         val = __raw_readl(w90p910_ts->ts_reg + 0x04);
 176         __raw_writel(val & TSC_FOURWIRE, w90p910_ts->ts_reg + 0x04);
 177         __raw_writel(ADC_DELAY, w90p910_ts->ts_reg + 0x08);
 178
 179         w90p910_ts->state = TS_WAIT_NEW_PACKET;
 180         wmb();
 181
 182         /* set trigger mode */
 183         val = __raw_readl(w90p910_ts->ts_reg);
 184         val |= ADC_WAITTRIG | ADC_DIV | ADC_EN | WT_INT_EN;
 185         __raw_writel(val, w90p910_ts->ts_reg);
 186
 187         return 0;
 188 }
 189
 190 static void w90p910_close(struct input_dev *dev)
 191 {
 192         struct w90p910_ts *w90p910_ts = input_get_drvdata(dev);
 193         unsigned long val;
 194
 195         /* disable trigger mode */
 196
 197         spin_lock_irq(&w90p910_ts->lock);
 198
 199         w90p910_ts->state = TS_IDLE;
 200
 201         val = __raw_readl(w90p910_ts->ts_reg);
 202         val &= ~(ADC_WAITTRIG | ADC_DIV | ADC_EN | WT_INT_EN | ADC_INT_EN);
 203         __raw_writel(val, w90p910_ts->ts_reg);
 204
 205         spin_unlock_irq(&w90p910_ts->lock);
 206
 207         /* Now that interrupts are shut off we can safely delete timer */
 208         del_timer_sync(&w90p910_ts->timer);
 209
 210         /* stop the ADC clock */
 211         clk_disable(w90p910_ts->clk);
 212 }
 213
 214 static int w90x900ts_probe(struct platform_device *pdev)
 215 {
 216         struct w90p910_ts *w90p910_ts;
 217         struct input_dev *input_dev;
 218         struct resource *res;
 219         int err;
 220
 221         w90p910_ts = kzalloc(sizeof(struct w90p910_ts), GFP_KERNEL);
 222         input_dev = input_allocate_device();
 223         if (!w90p910_ts || !input_dev) {
 224                 err = -ENOMEM;
 225                 goto fail1;
 226         }
 227
 228         w90p910_ts->input = input_dev;
 229         w90p910_ts->state = TS_IDLE;
 230         spin_lock_init(&w90p910_ts->lock);
 231         timer_setup(&w90p910_ts->timer, w90p910_check_pen_up, 0);
 232
 233         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 234         if (!res) {
 235                 err = -ENXIO;
 236                 goto fail1;
 237         }
 238
 239         if (!request_mem_region(res->start, resource_size(res),
 240                                 pdev->name)) {
 241                 err = -EBUSY;
 242                 goto fail1;
 243         }
 244
 245         w90p910_ts->ts_reg = ioremap(res->start, resource_size(res));
 246         if (!w90p910_ts->ts_reg) {
 247                 err = -ENOMEM;
 248                 goto fail2;
 249         }
 250
 251         w90p910_ts->clk = clk_get(&pdev->dev, NULL);
 252         if (IS_ERR(w90p910_ts->clk)) {
 253                 err = PTR_ERR(w90p910_ts->clk);
 254                 goto fail3;
 255         }
 256
 257         input_dev->name = "W90P910 TouchScreen";
 258         input_dev->phys = "w90p910ts/event0";
 259         input_dev->id.bustype = BUS_HOST;
 260         input_dev->id.vendor  = 0x0005;
 261         input_dev->id.product = 0x0001;
 262         input_dev->id.version = 0x0100;
 263         input_dev->dev.parent = &pdev->dev;
 264         input_dev->open = w90p910_open;
 265         input_dev->close = w90p910_close;
 266
 267         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 268         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 269
 270         input_set_abs_params(input_dev, ABS_X, 0, 0x400, 0, 0);
 271         input_set_abs_params(input_dev, ABS_Y, 0, 0x400, 0, 0);
 272
 273         input_set_drvdata(input_dev, w90p910_ts);
 274
 275         w90p910_ts->irq_num = platform_get_irq(pdev, 0);
 276         if (request_irq(w90p910_ts->irq_num, w90p910_ts_interrupt,
 277                         0, "w90p910ts", w90p910_ts)) {
 278                 err = -EBUSY;
 279                 goto fail4;
 280         }
 281
 282         err = input_register_device(w90p910_ts->input);
 283         if (err)
 284                 goto fail5;
 285
 286         platform_set_drvdata(pdev, w90p910_ts);
 287
 288         return 0;
 289
 290 fail5:  free_irq(w90p910_ts->irq_num, w90p910_ts);
 291 fail4:  clk_put(w90p910_ts->clk);
 292 fail3:  iounmap(w90p910_ts->ts_reg);
 293 fail2:  release_mem_region(res->start, resource_size(res));
 294 fail1:  input_free_device(input_dev);
 295         kfree(w90p910_ts);
 296         return err;
 297 }
 298
 299 static int w90x900ts_remove(struct platform_device *pdev)
 300 {
 301         struct w90p910_ts *w90p910_ts = platform_get_drvdata(pdev);
 302         struct resource *res;
 303
 304         free_irq(w90p910_ts->irq_num, w90p910_ts);
 305         del_timer_sync(&w90p910_ts->timer);
 306         iounmap(w90p910_ts->ts_reg);
 307
 308         clk_put(w90p910_ts->clk);
 309
 310         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 311         release_mem_region(res->start, resource_size(res));
 312
 313         input_unregister_device(w90p910_ts->input);
 314         kfree(w90p910_ts);
 315
 316         return 0;
 317 }
 318
 319 static struct platform_driver w90x900ts_driver = {
 320         .probe          = w90x900ts_probe,
 321         .remove         = w90x900ts_remove,
 322         .driver         = {
 323                 .name   = "nuc900-ts",
 324         },
 325 };
 326 module_platform_driver(w90x900ts_driver);
 327
 328 MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
 329 MODULE_DESCRIPTION("w90p910 touch screen driver!");
 330 MODULE_LICENSE("GPL");
 331 MODULE_ALIAS("platform:nuc900-ts");