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  * s.a. A20 User Manual "1.15 TP" (Documentation/arm/sunxi/README)
  35  * (looks like the description in the A20 User Manual v1.3 is better
  36  * than the one in the A10 User Manual v.1.5)
  37  */
  38
  39 #include <linux/err.h>
  40 #include <linux/hwmon.h>
  41 #include <linux/thermal.h>
  42 #include <linux/init.h>
  43 #include <linux/input.h>
  44 #include <linux/interrupt.h>
  45 #include <linux/io.h>
  46 #include <linux/module.h>
  47 #include <linux/of_platform.h>
  48 #include <linux/platform_device.h>
  49 #include <linux/slab.h>
  50
  51 #define TP_CTRL0                0x00
  52 #define TP_CTRL1                0x04
  53 #define TP_CTRL2                0x08
  54 #define TP_CTRL3                0x0c
  55 #define TP_INT_FIFOC            0x10
  56 #define TP_INT_FIFOS            0x14
  57 #define TP_TPR                  0x18
  58 #define TP_CDAT                 0x1c
  59 #define TEMP_DATA               0x20
  60 #define TP_DATA                 0x24
  61
  62 /* TP_CTRL0 bits */
  63 #define ADC_FIRST_DLY(x)        ((x) << 24) /* 8 bits */
  64 #define ADC_FIRST_DLY_MODE(x)   ((x) << 23)
  65 #define ADC_CLK_SEL(x)          ((x) << 22)
  66 #define ADC_CLK_DIV(x)          ((x) << 20) /* 3 bits */
  67 #define FS_DIV(x)               ((x) << 16) /* 4 bits */
  68 #define T_ACQ(x)                ((x) << 0) /* 16 bits */
  69
  70 /* TP_CTRL1 bits */
  71 #define STYLUS_UP_DEBOUN(x)     ((x) << 12) /* 8 bits */
  72 #define STYLUS_UP_DEBOUN_EN(x)  ((x) << 9)
  73 #define TOUCH_PAN_CALI_EN(x)    ((x) << 6)
  74 #define TP_DUAL_EN(x)           ((x) << 5)
  75 #define TP_MODE_EN(x)           ((x) << 4)
  76 #define TP_ADC_SELECT(x)        ((x) << 3)
  77 #define ADC_CHAN_SELECT(x)      ((x) << 0)  /* 3 bits */
  78
  79 /* on sun6i, bits 3~6 are left shifted by 1 to 4~7 */
  80 #define SUN6I_TP_MODE_EN(x)     ((x) << 5)
  81
  82 /* TP_CTRL2 bits */
  83 #define TP_SENSITIVE_ADJUST(x)  ((x) << 28) /* 4 bits */
  84 #define TP_MODE_SELECT(x)       ((x) << 26) /* 2 bits */
  85 #define PRE_MEA_EN(x)           ((x) << 24)
  86 #define PRE_MEA_THRE_CNT(x)     ((x) << 0) /* 24 bits */
  87
  88 /* TP_CTRL3 bits */
  89 #define FILTER_EN(x)            ((x) << 2)
  90 #define FILTER_TYPE(x)          ((x) << 0)  /* 2 bits */
  91
  92 /* TP_INT_FIFOC irq and fifo mask / control bits */
  93 #define TEMP_IRQ_EN(x)          ((x) << 18)
  94 #define OVERRUN_IRQ_EN(x)       ((x) << 17)
  95 #define DATA_IRQ_EN(x)          ((x) << 16)
  96 #define TP_DATA_XY_CHANGE(x)    ((x) << 13)
  97 #define FIFO_TRIG(x)            ((x) << 8)  /* 5 bits */
  98 #define DATA_DRQ_EN(x)          ((x) << 7)
  99 #define FIFO_FLUSH(x)           ((x) << 4)
 100 #define TP_UP_IRQ_EN(x)         ((x) << 1)
 101 #define TP_DOWN_IRQ_EN(x)       ((x) << 0)
 102
 103 /* TP_INT_FIFOS irq and fifo status bits */
 104 #define TEMP_DATA_PENDING       BIT(18)
 105 #define FIFO_OVERRUN_PENDING    BIT(17)
 106 #define FIFO_DATA_PENDING       BIT(16)
 107 #define TP_IDLE_FLG             BIT(2)
 108 #define TP_UP_PENDING           BIT(1)
 109 #define TP_DOWN_PENDING         BIT(0)
 110
 111 /* TP_TPR bits */
 112 #define TEMP_ENABLE(x)          ((x) << 16)
 113 #define TEMP_PERIOD(x)          ((x) << 0)  /* t = x * 256 * 16 / clkin */
 114
 115 struct sun4i_ts_data {
 116         struct device *dev;
 117         struct input_dev *input;
 118         void __iomem *base;
 119         unsigned int irq;
 120         bool ignore_fifo_data;
 121         int temp_data;
 122         int temp_offset;
 123         int temp_step;
 124 };
 125
 126 static void sun4i_ts_irq_handle_input(struct sun4i_ts_data *ts, u32 reg_val)
 127 {
 128         u32 x, y;
 129
 130         if (reg_val & FIFO_DATA_PENDING) {
 131                 x = readl(ts->base + TP_DATA);
 132                 y = readl(ts->base + TP_DATA);
 133                 /* The 1st location reported after an up event is unreliable */
 134                 if (!ts->ignore_fifo_data) {
 135                         input_report_abs(ts->input, ABS_X, x);
 136                         input_report_abs(ts->input, ABS_Y, y);
 137                         /*
 138                          * The hardware has a separate down status bit, but
 139                          * that gets set before we get the first location,
 140                          * resulting in reporting a click on the old location.
 141                          */
 142                         input_report_key(ts->input, BTN_TOUCH, 1);
 143                         input_sync(ts->input);
 144                 } else {
 145                         ts->ignore_fifo_data = false;
 146                 }
 147         }
 148
 149         if (reg_val & TP_UP_PENDING) {
 150                 ts->ignore_fifo_data = true;
 151                 input_report_key(ts->input, BTN_TOUCH, 0);
 152                 input_sync(ts->input);
 153         }
 154 }
 155
 156 static irqreturn_t sun4i_ts_irq(int irq, void *dev_id)
 157 {
 158         struct sun4i_ts_data *ts = dev_id;
 159         u32 reg_val;
 160
 161         reg_val  = readl(ts->base + TP_INT_FIFOS);
 162
 163         if (reg_val & TEMP_DATA_PENDING)
 164                 ts->temp_data = readl(ts->base + TEMP_DATA);
 165
 166         if (ts->input)
 167                 sun4i_ts_irq_handle_input(ts, reg_val);
 168
 169         writel(reg_val, ts->base + TP_INT_FIFOS);
 170
 171         return IRQ_HANDLED;
 172 }
 173
 174 static int sun4i_ts_open(struct input_dev *dev)
 175 {
 176         struct sun4i_ts_data *ts = input_get_drvdata(dev);
 177
 178         /* Flush, set trig level to 1, enable temp, data and up irqs */
 179         writel(TEMP_IRQ_EN(1) | DATA_IRQ_EN(1) | FIFO_TRIG(1) | FIFO_FLUSH(1) |
 180                 TP_UP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
 181
 182         return 0;
 183 }
 184
 185 static void sun4i_ts_close(struct input_dev *dev)
 186 {
 187         struct sun4i_ts_data *ts = input_get_drvdata(dev);
 188
 189         /* Deactivate all input IRQs */
 190         writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
 191 }
 192
 193 static int sun4i_get_temp(const struct sun4i_ts_data *ts, int *temp)
 194 {
 195         /* No temp_data until the first irq */
 196         if (ts->temp_data == -1)
 197                 return -EAGAIN;
 198
 199         *temp = ts->temp_data * ts->temp_step - ts->temp_offset;
 200
 201         return 0;
 202 }
 203
 204 static int sun4i_get_tz_temp(void *data, int *temp)
 205 {
 206         return sun4i_get_temp(data, temp);
 207 }
 208
 209 static struct thermal_zone_of_device_ops sun4i_ts_tz_ops = {
 210         .get_temp = sun4i_get_tz_temp,
 211 };
 212
 213 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 214                          char *buf)
 215 {
 216         struct sun4i_ts_data *ts = dev_get_drvdata(dev);
 217         int temp;
 218         int error;
 219
 220         error = sun4i_get_temp(ts, &temp);
 221         if (error)
 222                 return error;
 223
 224         return sprintf(buf, "%d\n", temp);
 225 }
 226
 227 static ssize_t show_temp_label(struct device *dev,
 228                               struct device_attribute *devattr, char *buf)
 229 {
 230         return sprintf(buf, "SoC temperature\n");
 231 }
 232
 233 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
 234 static DEVICE_ATTR(temp1_label, S_IRUGO, show_temp_label, NULL);
 235
 236 static struct attribute *sun4i_ts_attrs[] = {
 237         &dev_attr_temp1_input.attr,
 238         &dev_attr_temp1_label.attr,
 239         NULL
 240 };
 241 ATTRIBUTE_GROUPS(sun4i_ts);
 242
 243 static int sun4i_ts_probe(struct platform_device *pdev)
 244 {
 245         struct sun4i_ts_data *ts;
 246         struct device *dev = &pdev->dev;
 247         struct device_node *np = dev->of_node;
 248         struct device *hwmon;
 249         int error;
 250         u32 reg;
 251         bool ts_attached;
 252         u32 tp_sensitive_adjust = 15;
 253         u32 filter_type = 1;
 254
 255         ts = devm_kzalloc(dev, sizeof(struct sun4i_ts_data), GFP_KERNEL);
 256         if (!ts)
 257                 return -ENOMEM;
 258
 259         ts->dev = dev;
 260         ts->ignore_fifo_data = true;
 261         ts->temp_data = -1;
 262         if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts")) {
 263                 /* Allwinner SDK has temperature (C) = (value / 6) - 271 */
 264                 ts->temp_offset = 271000;
 265                 ts->temp_step = 167;
 266         } else if (of_device_is_compatible(np, "allwinner,sun4i-a10-ts")) {
 267                 /*
 268                  * The A10 temperature sensor has quite a wide spread, these
 269                  * parameters are based on the averaging of the calibration
 270                  * results of 4 completely different boards, with a spread of
 271                  * temp_step from 0.096 - 0.170 and temp_offset from 176 - 331.
 272                  */
 273                 ts->temp_offset = 257000;
 274                 ts->temp_step = 133;
 275         } else {
 276                 /*
 277                  * The user manuals do not contain the formula for calculating
 278                  * the temperature. The formula used here is from the AXP209,
 279                  * which is designed by X-Powers, an affiliate of Allwinner:
 280                  *
 281                  *     temperature (C) = (value * 0.1) - 144.7
 282                  *
 283                  * Allwinner does not have any documentation whatsoever for
 284                  * this hardware. Moreover, it is claimed that the sensor
 285                  * is inaccurate and cannot work properly.
 286                  */
 287                 ts->temp_offset = 144700;
 288                 ts->temp_step = 100;
 289         }
 290
 291         ts_attached = of_property_read_bool(np, "allwinner,ts-attached");
 292         if (ts_attached) {
 293                 ts->input = devm_input_allocate_device(dev);
 294                 if (!ts->input)
 295                         return -ENOMEM;
 296
 297                 ts->input->name = pdev->name;
 298                 ts->input->phys = "sun4i_ts/input0";
 299                 ts->input->open = sun4i_ts_open;
 300                 ts->input->close = sun4i_ts_close;
 301                 ts->input->id.bustype = BUS_HOST;
 302                 ts->input->id.vendor = 0x0001;
 303                 ts->input->id.product = 0x0001;
 304                 ts->input->id.version = 0x0100;
 305                 ts->input->evbit[0] =  BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);
 306                 __set_bit(BTN_TOUCH, ts->input->keybit);
 307                 input_set_abs_params(ts->input, ABS_X, 0, 4095, 0, 0);
 308                 input_set_abs_params(ts->input, ABS_Y, 0, 4095, 0, 0);
 309                 input_set_drvdata(ts->input, ts);
 310         }
 311
 312         ts->base = devm_ioremap_resource(dev,
 313                               platform_get_resource(pdev, IORESOURCE_MEM, 0));
 314         if (IS_ERR(ts->base))
 315                 return PTR_ERR(ts->base);
 316
 317         ts->irq = platform_get_irq(pdev, 0);
 318         error = devm_request_irq(dev, ts->irq, sun4i_ts_irq, 0, "sun4i-ts", ts);
 319         if (error)
 320                 return error;
 321
 322         /*
 323          * Select HOSC clk, clkin = clk / 6, adc samplefreq = clkin / 8192,
 324          * t_acq = clkin / (16 * 64)
 325          */
 326         writel(ADC_CLK_SEL(0) | ADC_CLK_DIV(2) | FS_DIV(7) | T_ACQ(63),
 327                ts->base + TP_CTRL0);
 328
 329         /*
 330          * tp_sensitive_adjust is an optional property
 331          * tp_mode = 0 : only x and y coordinates, as we don't use dual touch
 332          */
 333         of_property_read_u32(np, "allwinner,tp-sensitive-adjust",
 334                              &tp_sensitive_adjust);
 335         writel(TP_SENSITIVE_ADJUST(tp_sensitive_adjust) | TP_MODE_SELECT(0),
 336                ts->base + TP_CTRL2);
 337
 338         /*
 339          * Enable median and averaging filter, optional property for
 340          * filter type.
 341          */
 342         of_property_read_u32(np, "allwinner,filter-type", &filter_type);
 343         writel(FILTER_EN(1) | FILTER_TYPE(filter_type), ts->base + TP_CTRL3);
 344
 345         /* Enable temperature measurement, period 1953 (2 seconds) */
 346         writel(TEMP_ENABLE(1) | TEMP_PERIOD(1953), ts->base + TP_TPR);
 347
 348         /*
 349          * Set stylus up debounce to aprox 10 ms, enable debounce, and
 350          * finally enable tp mode.
 351          */
 352         reg = STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1);
 353         if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts"))
 354                 reg |= SUN6I_TP_MODE_EN(1);
 355         else
 356                 reg |= TP_MODE_EN(1);
 357         writel(reg, ts->base + TP_CTRL1);
 358
 359         /*
 360          * The thermal core does not register hwmon devices for DT-based
 361          * thermal zone sensors, such as this one.
 362          */
 363         hwmon = devm_hwmon_device_register_with_groups(ts->dev, "sun4i_ts",
 364                                                        ts, sun4i_ts_groups);
 365         if (IS_ERR(hwmon))
 366                 return PTR_ERR(hwmon);
 367
 368         devm_thermal_zone_of_sensor_register(ts->dev, 0, ts, &sun4i_ts_tz_ops);
 369
 370         writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
 371
 372         if (ts_attached) {
 373                 error = input_register_device(ts->input);
 374                 if (error) {
 375                         writel(0, ts->base + TP_INT_FIFOC);
 376                         return error;
 377                 }
 378         }
 379
 380         platform_set_drvdata(pdev, ts);
 381         return 0;
 382 }
 383
 384 static int sun4i_ts_remove(struct platform_device *pdev)
 385 {
 386         struct sun4i_ts_data *ts = platform_get_drvdata(pdev);
 387
 388         /* Explicit unregister to avoid open/close changing the imask later */
 389         if (ts->input)
 390                 input_unregister_device(ts->input);
 391
 392         /* Deactivate all IRQs */
 393         writel(0, ts->base + TP_INT_FIFOC);
 394
 395         return 0;
 396 }
 397
 398 static const struct of_device_id sun4i_ts_of_match[] = {
 399         { .compatible = "allwinner,sun4i-a10-ts", },
 400         { .compatible = "allwinner,sun5i-a13-ts", },
 401         { .compatible = "allwinner,sun6i-a31-ts", },
 402         { /* sentinel */ }
 403 };
 404 MODULE_DEVICE_TABLE(of, sun4i_ts_of_match);
 405
 406 static struct platform_driver sun4i_ts_driver = {
 407         .driver = {
 408                 .name   = "sun4i-ts",
 409                 .of_match_table = of_match_ptr(sun4i_ts_of_match),
 410         },
 411         .probe  = sun4i_ts_probe,
 412         .remove = sun4i_ts_remove,
 413 };
 414
 415 module_platform_driver(sun4i_ts_driver);
 416
 417 MODULE_DESCRIPTION("Allwinner sun4i resistive touchscreen controller driver");
 418 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 419 MODULE_LICENSE("GPL");