drivers/input/touchscreen/sun4i-ts.c

   1 /*
   2  * Allwinner sunxi resistive touchscreen controller driver
   3  *
   4  * Copyright (C) 2013 - 2014 Hans de Goede <hdegoede@redhat.com>
   5  *
   6  * The hwmon parts are based on work by Corentin LABBE which is:
   7  * Copyright (C) 2013 Corentin LABBE <clabbe.montjoie@gmail.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  */
  19
  20 /*
  21  * The sun4i-ts controller is capable of detecting a second touch, but when a
  22  * second touch is present then the accuracy becomes so bad the reported touch
  23  * location is not useable.
  24  *
  25  * The original android driver contains some complicated heuristics using the
  26  * aprox. distance between the 2 touches to see if the user is making a pinch
  27  * open / close movement, and then reports emulated multi-touch events around
  28  * the last touch coordinate (as the dual-touch coordinates are worthless).
  29  *
  30  * These kinds of heuristics are just asking for trouble (and don't belong
  31  * in the kernel). So this driver offers straight forward, reliable single
  32  * touch functionality only.
  33  */
  34
  35 #include <linux/err.h>
  36 #include <linux/hwmon.h>
  37 #include <linux/init.h>
  38 #include <linux/input.h>
  39 #include <linux/interrupt.h>
  40 #include <linux/io.h>
  41 #include <linux/module.h>
  42 #include <linux/of_platform.h>
  43 #include <linux/platform_device.h>
  44 #include <linux/slab.h>
  45
  46 #define TP_CTRL0                0x00
  47 #define TP_CTRL1                0x04
  48 #define TP_CTRL2                0x08
  49 #define TP_CTRL3                0x0c
  50 #define TP_INT_FIFOC            0x10
  51 #define TP_INT_FIFOS            0x14
  52 #define TP_TPR                  0x18
  53 #define TP_CDAT                 0x1c
  54 #define TEMP_DATA               0x20
  55 #define TP_DATA                 0x24
  56
  57 /* TP_CTRL0 bits */
  58 #define ADC_FIRST_DLY(x)        ((x) << 24) /* 8 bits */
  59 #define ADC_FIRST_DLY_MODE(x)   ((x) << 23)
  60 #define ADC_CLK_SEL(x)          ((x) << 22)
  61 #define ADC_CLK_DIV(x)          ((x) << 20) /* 3 bits */
  62 #define FS_DIV(x)               ((x) << 16) /* 4 bits */
  63 #define T_ACQ(x)                ((x) << 0) /* 16 bits */
  64
  65 /* TP_CTRL1 bits */
  66 #define STYLUS_UP_DEBOUN(x)     ((x) << 12) /* 8 bits */
  67 #define STYLUS_UP_DEBOUN_EN(x)  ((x) << 9)
  68 #define TOUCH_PAN_CALI_EN(x)    ((x) << 6)
  69 #define TP_DUAL_EN(x)           ((x) << 5)
  70 #define TP_MODE_EN(x)           ((x) << 4)
  71 #define TP_ADC_SELECT(x)        ((x) << 3)
  72 #define ADC_CHAN_SELECT(x)      ((x) << 0)  /* 3 bits */
  73
  74 /* TP_CTRL2 bits */
  75 #define TP_SENSITIVE_ADJUST(x)  ((x) << 28) /* 4 bits */
  76 #define TP_MODE_SELECT(x)       ((x) << 26) /* 2 bits */
  77 #define PRE_MEA_EN(x)           ((x) << 24)
  78 #define PRE_MEA_THRE_CNT(x)     ((x) << 0) /* 24 bits */
  79
  80 /* TP_CTRL3 bits */
  81 #define FILTER_EN(x)            ((x) << 2)
  82 #define FILTER_TYPE(x)          ((x) << 0)  /* 2 bits */
  83
  84 /* TP_INT_FIFOC irq and fifo mask / control bits */
  85 #define TEMP_IRQ_EN(x)          ((x) << 18)
  86 #define OVERRUN_IRQ_EN(x)       ((x) << 17)
  87 #define DATA_IRQ_EN(x)          ((x) << 16)
  88 #define TP_DATA_XY_CHANGE(x)    ((x) << 13)
  89 #define FIFO_TRIG(x)            ((x) << 8)  /* 5 bits */
  90 #define DATA_DRQ_EN(x)          ((x) << 7)
  91 #define FIFO_FLUSH(x)           ((x) << 4)
  92 #define TP_UP_IRQ_EN(x)         ((x) << 1)
  93 #define TP_DOWN_IRQ_EN(x)       ((x) << 0)
  94
  95 /* TP_INT_FIFOS irq and fifo status bits */
  96 #define TEMP_DATA_PENDING       BIT(18)
  97 #define FIFO_OVERRUN_PENDING    BIT(17)
  98 #define FIFO_DATA_PENDING       BIT(16)
  99 #define TP_IDLE_FLG             BIT(2)
 100 #define TP_UP_PENDING           BIT(1)
 101 #define TP_DOWN_PENDING         BIT(0)
 102
 103 /* TP_TPR bits */
 104 #define TEMP_ENABLE(x)          ((x) << 16)
 105 #define TEMP_PERIOD(x)          ((x) << 0)  /* t = x * 256 * 16 / clkin */
 106
 107 struct sun4i_ts_data {
 108         struct device *dev;
 109         struct input_dev *input;
 110         void __iomem *base;
 111         unsigned int irq;
 112         bool ignore_fifo_data;
 113         int temp_data;
 114 };
 115
 116 static void sun4i_ts_irq_handle_input(struct sun4i_ts_data *ts, u32 reg_val)
 117 {
 118         u32 x, y;
 119
 120         if (reg_val & FIFO_DATA_PENDING) {
 121                 x = readl(ts->base + TP_DATA);
 122                 y = readl(ts->base + TP_DATA);
 123                 /* The 1st location reported after an up event is unreliable */
 124                 if (!ts->ignore_fifo_data) {
 125                         input_report_abs(ts->input, ABS_X, x);
 126                         input_report_abs(ts->input, ABS_Y, y);
 127                         /*
 128                          * The hardware has a separate down status bit, but
 129                          * that gets set before we get the first location,
 130                          * resulting in reporting a click on the old location.
 131                          */
 132                         input_report_key(ts->input, BTN_TOUCH, 1);
 133                         input_sync(ts->input);
 134                 } else {
 135                         ts->ignore_fifo_data = false;
 136                 }
 137         }
 138
 139         if (reg_val & TP_UP_PENDING) {
 140                 ts->ignore_fifo_data = true;
 141                 input_report_key(ts->input, BTN_TOUCH, 0);
 142                 input_sync(ts->input);
 143         }
 144 }
 145
 146 static irqreturn_t sun4i_ts_irq(int irq, void *dev_id)
 147 {
 148         struct sun4i_ts_data *ts = dev_id;
 149         u32 reg_val;
 150
 151         reg_val  = readl(ts->base + TP_INT_FIFOS);
 152
 153         if (reg_val & TEMP_DATA_PENDING)
 154                 ts->temp_data = readl(ts->base + TEMP_DATA);
 155
 156         if (ts->input)
 157                 sun4i_ts_irq_handle_input(ts, reg_val);
 158
 159         writel(reg_val, ts->base + TP_INT_FIFOS);
 160
 161         return IRQ_HANDLED;
 162 }
 163
 164 static int sun4i_ts_open(struct input_dev *dev)
 165 {
 166         struct sun4i_ts_data *ts = input_get_drvdata(dev);
 167
 168         /* Flush, set trig level to 1, enable temp, data and up irqs */
 169         writel(TEMP_IRQ_EN(1) | DATA_IRQ_EN(1) | FIFO_TRIG(1) | FIFO_FLUSH(1) |
 170                 TP_UP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
 171
 172         return 0;
 173 }
 174
 175 static void sun4i_ts_close(struct input_dev *dev)
 176 {
 177         struct sun4i_ts_data *ts = input_get_drvdata(dev);
 178
 179         /* Deactivate all input IRQs */
 180         writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
 181 }
 182
 183 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 184                          char *buf)
 185 {
 186         struct sun4i_ts_data *ts = dev_get_drvdata(dev);
 187
 188         /* No temp_data until the first irq */
 189         if (ts->temp_data == -1)
 190                 return -EAGAIN;
 191
 192         return sprintf(buf, "%d\n", (ts->temp_data - 1447) * 100);
 193 }
 194
 195 static ssize_t show_temp_label(struct device *dev,
 196                               struct device_attribute *devattr, char *buf)
 197 {
 198         return sprintf(buf, "SoC temperature\n");
 199 }
 200
 201 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
 202 static DEVICE_ATTR(temp1_label, S_IRUGO, show_temp_label, NULL);
 203
 204 static struct attribute *sun4i_ts_attrs[] = {
 205         &dev_attr_temp1_input.attr,
 206         &dev_attr_temp1_label.attr,
 207         NULL
 208 };
 209 ATTRIBUTE_GROUPS(sun4i_ts);
 210
 211 static int sun4i_ts_probe(struct platform_device *pdev)
 212 {
 213         struct sun4i_ts_data *ts;
 214         struct device *dev = &pdev->dev;
 215         struct device_node *np = dev->of_node;
 216         struct device *hwmon;
 217         int error;
 218         bool ts_attached;
 219
 220         ts = devm_kzalloc(dev, sizeof(struct sun4i_ts_data), GFP_KERNEL);
 221         if (!ts)
 222                 return -ENOMEM;
 223
 224         ts->dev = dev;
 225         ts->ignore_fifo_data = true;
 226         ts->temp_data = -1;
 227
 228         ts_attached = of_property_read_bool(np, "allwinner,ts-attached");
 229         if (ts_attached) {
 230                 ts->input = devm_input_allocate_device(dev);
 231                 if (!ts->input)
 232                         return -ENOMEM;
 233
 234                 ts->input->name = pdev->name;
 235                 ts->input->phys = "sun4i_ts/input0";
 236                 ts->input->open = sun4i_ts_open;
 237                 ts->input->close = sun4i_ts_close;
 238                 ts->input->id.bustype = BUS_HOST;
 239                 ts->input->id.vendor = 0x0001;
 240                 ts->input->id.product = 0x0001;
 241                 ts->input->id.version = 0x0100;
 242                 ts->input->evbit[0] =  BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);
 243                 __set_bit(BTN_TOUCH, ts->input->keybit);
 244                 input_set_abs_params(ts->input, ABS_X, 0, 4095, 0, 0);
 245                 input_set_abs_params(ts->input, ABS_Y, 0, 4095, 0, 0);
 246                 input_set_drvdata(ts->input, ts);
 247         }
 248
 249         ts->base = devm_ioremap_resource(dev,
 250                               platform_get_resource(pdev, IORESOURCE_MEM, 0));
 251         if (IS_ERR(ts->base))
 252                 return PTR_ERR(ts->base);
 253
 254         ts->irq = platform_get_irq(pdev, 0);
 255         error = devm_request_irq(dev, ts->irq, sun4i_ts_irq, 0, "sun4i-ts", ts);
 256         if (error)
 257                 return error;
 258
 259         /*
 260          * Select HOSC clk, clkin = clk / 6, adc samplefreq = clkin / 8192,
 261          * t_acq = clkin / (16 * 64)
 262          */
 263         writel(ADC_CLK_SEL(0) | ADC_CLK_DIV(2) | FS_DIV(7) | T_ACQ(63),
 264                ts->base + TP_CTRL0);
 265
 266         /*
 267          * sensitive_adjust = 15 : max, which is not all that sensitive,
 268          * tp_mode = 0 : only x and y coordinates, as we don't use dual touch
 269          */
 270         writel(TP_SENSITIVE_ADJUST(15) | TP_MODE_SELECT(0),
 271                ts->base + TP_CTRL2);
 272
 273         /* Enable median filter, type 1 : 5/3 */
 274         writel(FILTER_EN(1) | FILTER_TYPE(1), ts->base + TP_CTRL3);
 275
 276         /* Enable temperature measurement, period 1953 (2 seconds) */
 277         writel(TEMP_ENABLE(1) | TEMP_PERIOD(1953), ts->base + TP_TPR);
 278
 279         /*
 280          * Set stylus up debounce to aprox 10 ms, enable debounce, and
 281          * finally enable tp mode.
 282          */
 283         writel(STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1) | TP_MODE_EN(1),
 284                ts->base + TP_CTRL1);
 285
 286         hwmon = devm_hwmon_device_register_with_groups(ts->dev, "sun4i_ts",
 287                                                        ts, sun4i_ts_groups);
 288         if (IS_ERR(hwmon))
 289                 return PTR_ERR(hwmon);
 290
 291         writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
 292
 293         if (ts_attached) {
 294                 error = input_register_device(ts->input);
 295                 if (error) {
 296                         writel(0, ts->base + TP_INT_FIFOC);
 297                         return error;
 298                 }
 299         }
 300
 301         platform_set_drvdata(pdev, ts);
 302         return 0;
 303 }
 304
 305 static int sun4i_ts_remove(struct platform_device *pdev)
 306 {
 307         struct sun4i_ts_data *ts = platform_get_drvdata(pdev);
 308
 309         /* Explicit unregister to avoid open/close changing the imask later */
 310         if (ts->input)
 311                 input_unregister_device(ts->input);
 312
 313         /* Deactivate all IRQs */
 314         writel(0, ts->base + TP_INT_FIFOC);
 315
 316         return 0;
 317 }
 318
 319 static const struct of_device_id sun4i_ts_of_match[] = {
 320         { .compatible = "allwinner,sun4i-a10-ts", },
 321         { /* sentinel */ }
 322 };
 323 MODULE_DEVICE_TABLE(of, sun4i_ts_of_match);
 324
 325 static struct platform_driver sun4i_ts_driver = {
 326         .driver = {
 327                 .owner  = THIS_MODULE,
 328                 .name   = "sun4i-ts",
 329                 .of_match_table = of_match_ptr(sun4i_ts_of_match),
 330         },
 331         .probe  = sun4i_ts_probe,
 332         .remove = sun4i_ts_remove,
 333 };
 334
 335 module_platform_driver(sun4i_ts_driver);
 336
 337 MODULE_DESCRIPTION("Allwinner sun4i resistive touchscreen controller driver");
 338 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 339 MODULE_LICENSE("GPL");