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/thermal.h>
  38 #include <linux/init.h>
  39 #include <linux/input.h>
  40 #include <linux/interrupt.h>
  41 #include <linux/io.h>
  42 #include <linux/module.h>
  43 #include <linux/of_platform.h>
  44 #include <linux/platform_device.h>
  45 #include <linux/slab.h>
  46
  47 #define TP_CTRL0                0x00
  48 #define TP_CTRL1                0x04
  49 #define TP_CTRL2                0x08
  50 #define TP_CTRL3                0x0c
  51 #define TP_INT_FIFOC            0x10
  52 #define TP_INT_FIFOS            0x14
  53 #define TP_TPR                  0x18
  54 #define TP_CDAT                 0x1c
  55 #define TEMP_DATA               0x20
  56 #define TP_DATA                 0x24
  57
  58 /* TP_CTRL0 bits */
  59 #define ADC_FIRST_DLY(x)        ((x) << 24) /* 8 bits */
  60 #define ADC_FIRST_DLY_MODE(x)   ((x) << 23)
  61 #define ADC_CLK_SEL(x)          ((x) << 22)
  62 #define ADC_CLK_DIV(x)          ((x) << 20) /* 3 bits */
  63 #define FS_DIV(x)               ((x) << 16) /* 4 bits */
  64 #define T_ACQ(x)                ((x) << 0) /* 16 bits */
  65
  66 /* TP_CTRL1 bits */
  67 #define STYLUS_UP_DEBOUN(x)     ((x) << 12) /* 8 bits */
  68 #define STYLUS_UP_DEBOUN_EN(x)  ((x) << 9)
  69 #define TOUCH_PAN_CALI_EN(x)    ((x) << 6)
  70 #define TP_DUAL_EN(x)           ((x) << 5)
  71 #define TP_MODE_EN(x)           ((x) << 4)
  72 #define TP_ADC_SELECT(x)        ((x) << 3)
  73 #define ADC_CHAN_SELECT(x)      ((x) << 0)  /* 3 bits */
  74
  75 /* on sun6i, bits 3~6 are left shifted by 1 to 4~7 */
  76 #define SUN6I_TP_MODE_EN(x)     ((x) << 5)
  77
  78 /* TP_CTRL2 bits */
  79 #define TP_SENSITIVE_ADJUST(x)  ((x) << 28) /* 4 bits */
  80 #define TP_MODE_SELECT(x)       ((x) << 26) /* 2 bits */
  81 #define PRE_MEA_EN(x)           ((x) << 24)
  82 #define PRE_MEA_THRE_CNT(x)     ((x) << 0) /* 24 bits */
  83
  84 /* TP_CTRL3 bits */
  85 #define FILTER_EN(x)            ((x) << 2)
  86 #define FILTER_TYPE(x)          ((x) << 0)  /* 2 bits */
  87
  88 /* TP_INT_FIFOC irq and fifo mask / control bits */
  89 #define TEMP_IRQ_EN(x)          ((x) << 18)
  90 #define OVERRUN_IRQ_EN(x)       ((x) << 17)
  91 #define DATA_IRQ_EN(x)          ((x) << 16)
  92 #define TP_DATA_XY_CHANGE(x)    ((x) << 13)
  93 #define FIFO_TRIG(x)            ((x) << 8)  /* 5 bits */
  94 #define DATA_DRQ_EN(x)          ((x) << 7)
  95 #define FIFO_FLUSH(x)           ((x) << 4)
  96 #define TP_UP_IRQ_EN(x)         ((x) << 1)
  97 #define TP_DOWN_IRQ_EN(x)       ((x) << 0)
  98
  99 /* TP_INT_FIFOS irq and fifo status bits */
 100 #define TEMP_DATA_PENDING       BIT(18)
 101 #define FIFO_OVERRUN_PENDING    BIT(17)
 102 #define FIFO_DATA_PENDING       BIT(16)
 103 #define TP_IDLE_FLG             BIT(2)
 104 #define TP_UP_PENDING           BIT(1)
 105 #define TP_DOWN_PENDING         BIT(0)
 106
 107 /* TP_TPR bits */
 108 #define TEMP_ENABLE(x)          ((x) << 16)
 109 #define TEMP_PERIOD(x)          ((x) << 0)  /* t = x * 256 * 16 / clkin */
 110
 111 struct sun4i_ts_data {
 112         struct device *dev;
 113         struct input_dev *input;
 114         struct thermal_zone_device *tz;
 115         void __iomem *base;
 116         unsigned int irq;
 117         bool ignore_fifo_data;
 118         int temp_data;
 119         int temp_offset;
 120         int temp_step;
 121 };
 122
 123 static void sun4i_ts_irq_handle_input(struct sun4i_ts_data *ts, u32 reg_val)
 124 {
 125         u32 x, y;
 126
 127         if (reg_val & FIFO_DATA_PENDING) {
 128                 x = readl(ts->base + TP_DATA);
 129                 y = readl(ts->base + TP_DATA);
 130                 /* The 1st location reported after an up event is unreliable */
 131                 if (!ts->ignore_fifo_data) {
 132                         input_report_abs(ts->input, ABS_X, x);
 133                         input_report_abs(ts->input, ABS_Y, y);
 134                         /*
 135                          * The hardware has a separate down status bit, but
 136                          * that gets set before we get the first location,
 137                          * resulting in reporting a click on the old location.
 138                          */
 139                         input_report_key(ts->input, BTN_TOUCH, 1);
 140                         input_sync(ts->input);
 141                 } else {
 142                         ts->ignore_fifo_data = false;
 143                 }
 144         }
 145
 146         if (reg_val & TP_UP_PENDING) {
 147                 ts->ignore_fifo_data = true;
 148                 input_report_key(ts->input, BTN_TOUCH, 0);
 149                 input_sync(ts->input);
 150         }
 151 }
 152
 153 static irqreturn_t sun4i_ts_irq(int irq, void *dev_id)
 154 {
 155         struct sun4i_ts_data *ts = dev_id;
 156         u32 reg_val;
 157
 158         reg_val  = readl(ts->base + TP_INT_FIFOS);
 159
 160         if (reg_val & TEMP_DATA_PENDING)
 161                 ts->temp_data = readl(ts->base + TEMP_DATA);
 162
 163         if (ts->input)
 164                 sun4i_ts_irq_handle_input(ts, reg_val);
 165
 166         writel(reg_val, ts->base + TP_INT_FIFOS);
 167
 168         return IRQ_HANDLED;
 169 }
 170
 171 static int sun4i_ts_open(struct input_dev *dev)
 172 {
 173         struct sun4i_ts_data *ts = input_get_drvdata(dev);
 174
 175         /* Flush, set trig level to 1, enable temp, data and up irqs */
 176         writel(TEMP_IRQ_EN(1) | DATA_IRQ_EN(1) | FIFO_TRIG(1) | FIFO_FLUSH(1) |
 177                 TP_UP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
 178
 179         return 0;
 180 }
 181
 182 static void sun4i_ts_close(struct input_dev *dev)
 183 {
 184         struct sun4i_ts_data *ts = input_get_drvdata(dev);
 185
 186         /* Deactivate all input IRQs */
 187         writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
 188 }
 189
 190 static int sun4i_get_temp(const struct sun4i_ts_data *ts, long *temp)
 191 {
 192         /* No temp_data until the first irq */
 193         if (ts->temp_data == -1)
 194                 return -EAGAIN;
 195
 196         *temp = (ts->temp_data - ts->temp_offset) * ts->temp_step;
 197
 198         return 0;
 199 }
 200
 201 static int sun4i_get_tz_temp(void *data, long *temp)
 202 {
 203         return sun4i_get_temp(data, temp);
 204 }
 205
 206 static struct thermal_zone_of_device_ops sun4i_ts_tz_ops = {
 207         .get_temp = sun4i_get_tz_temp,
 208 };
 209
 210 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 211                          char *buf)
 212 {
 213         struct sun4i_ts_data *ts = dev_get_drvdata(dev);
 214         long temp;
 215         int error;
 216
 217         error = sun4i_get_temp(ts, &temp);
 218         if (error)
 219                 return error;
 220
 221         return sprintf(buf, "%ld\n", temp);
 222 }
 223
 224 static ssize_t show_temp_label(struct device *dev,
 225                               struct device_attribute *devattr, char *buf)
 226 {
 227         return sprintf(buf, "SoC temperature\n");
 228 }
 229
 230 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
 231 static DEVICE_ATTR(temp1_label, S_IRUGO, show_temp_label, NULL);
 232
 233 static struct attribute *sun4i_ts_attrs[] = {
 234         &dev_attr_temp1_input.attr,
 235         &dev_attr_temp1_label.attr,
 236         NULL
 237 };
 238 ATTRIBUTE_GROUPS(sun4i_ts);
 239
 240 static int sun4i_ts_probe(struct platform_device *pdev)
 241 {
 242         struct sun4i_ts_data *ts;
 243         struct device *dev = &pdev->dev;
 244         struct device_node *np = dev->of_node;
 245         struct device *hwmon;
 246         int error;
 247         u32 reg;
 248         bool ts_attached;
 249
 250         ts = devm_kzalloc(dev, sizeof(struct sun4i_ts_data), GFP_KERNEL);
 251         if (!ts)
 252                 return -ENOMEM;
 253
 254         ts->dev = dev;
 255         ts->ignore_fifo_data = true;
 256         ts->temp_data = -1;
 257         if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts")) {
 258                 /* Allwinner SDK has temperature = -271 + (value / 6) (C) */
 259                 ts->temp_offset = 1626;
 260                 ts->temp_step = 167;
 261         } else {
 262                 /*
 263                  * The user manuals do not contain the formula for calculating
 264                  * the temperature. The formula used here is from the AXP209,
 265                  * which is designed by X-Powers, an affiliate of Allwinner:
 266                  *
 267                  *     temperature = -144.7 + (value * 0.1)
 268                  *
 269                  * Allwinner does not have any documentation whatsoever for
 270                  * this hardware. Moreover, it is claimed that the sensor
 271                  * is inaccurate and cannot work properly.
 272                  */
 273                 ts->temp_offset = 1447;
 274                 ts->temp_step = 100;
 275         }
 276
 277         ts_attached = of_property_read_bool(np, "allwinner,ts-attached");
 278         if (ts_attached) {
 279                 ts->input = devm_input_allocate_device(dev);
 280                 if (!ts->input)
 281                         return -ENOMEM;
 282
 283                 ts->input->name = pdev->name;
 284                 ts->input->phys = "sun4i_ts/input0";
 285                 ts->input->open = sun4i_ts_open;
 286                 ts->input->close = sun4i_ts_close;
 287                 ts->input->id.bustype = BUS_HOST;
 288                 ts->input->id.vendor = 0x0001;
 289                 ts->input->id.product = 0x0001;
 290                 ts->input->id.version = 0x0100;
 291                 ts->input->evbit[0] =  BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);
 292                 __set_bit(BTN_TOUCH, ts->input->keybit);
 293                 input_set_abs_params(ts->input, ABS_X, 0, 4095, 0, 0);
 294                 input_set_abs_params(ts->input, ABS_Y, 0, 4095, 0, 0);
 295                 input_set_drvdata(ts->input, ts);
 296         }
 297
 298         ts->base = devm_ioremap_resource(dev,
 299                               platform_get_resource(pdev, IORESOURCE_MEM, 0));
 300         if (IS_ERR(ts->base))
 301                 return PTR_ERR(ts->base);
 302
 303         ts->irq = platform_get_irq(pdev, 0);
 304         error = devm_request_irq(dev, ts->irq, sun4i_ts_irq, 0, "sun4i-ts", ts);
 305         if (error)
 306                 return error;
 307
 308         /*
 309          * Select HOSC clk, clkin = clk / 6, adc samplefreq = clkin / 8192,
 310          * t_acq = clkin / (16 * 64)
 311          */
 312         writel(ADC_CLK_SEL(0) | ADC_CLK_DIV(2) | FS_DIV(7) | T_ACQ(63),
 313                ts->base + TP_CTRL0);
 314
 315         /*
 316          * sensitive_adjust = 15 : max, which is not all that sensitive,
 317          * tp_mode = 0 : only x and y coordinates, as we don't use dual touch
 318          */
 319         writel(TP_SENSITIVE_ADJUST(15) | TP_MODE_SELECT(0),
 320                ts->base + TP_CTRL2);
 321
 322         /* Enable median filter, type 1 : 5/3 */
 323         writel(FILTER_EN(1) | FILTER_TYPE(1), ts->base + TP_CTRL3);
 324
 325         /* Enable temperature measurement, period 1953 (2 seconds) */
 326         writel(TEMP_ENABLE(1) | TEMP_PERIOD(1953), ts->base + TP_TPR);
 327
 328         /*
 329          * Set stylus up debounce to aprox 10 ms, enable debounce, and
 330          * finally enable tp mode.
 331          */
 332         reg = STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1);
 333         if (of_device_is_compatible(np, "allwinner,sun4i-a10-ts"))
 334                 reg |= TP_MODE_EN(1);
 335         else
 336                 reg |= SUN6I_TP_MODE_EN(1);
 337         writel(reg, ts->base + TP_CTRL1);
 338
 339         /*
 340          * The thermal core does not register hwmon devices for DT-based
 341          * thermal zone sensors, such as this one.
 342          */
 343         hwmon = devm_hwmon_device_register_with_groups(ts->dev, "sun4i_ts",
 344                                                        ts, sun4i_ts_groups);
 345         if (IS_ERR(hwmon))
 346                 return PTR_ERR(hwmon);
 347
 348         ts->tz = thermal_zone_of_sensor_register(ts->dev, 0, ts,
 349                                                  &sun4i_ts_tz_ops);
 350         if (IS_ERR(ts->tz))
 351                 ts->tz = NULL;
 352
 353         writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
 354
 355         if (ts_attached) {
 356                 error = input_register_device(ts->input);
 357                 if (error) {
 358                         writel(0, ts->base + TP_INT_FIFOC);
 359                         thermal_zone_of_sensor_unregister(ts->dev, ts->tz);
 360                         return error;
 361                 }
 362         }
 363
 364         platform_set_drvdata(pdev, ts);
 365         return 0;
 366 }
 367
 368 static int sun4i_ts_remove(struct platform_device *pdev)
 369 {
 370         struct sun4i_ts_data *ts = platform_get_drvdata(pdev);
 371
 372         /* Explicit unregister to avoid open/close changing the imask later */
 373         if (ts->input)
 374                 input_unregister_device(ts->input);
 375
 376         thermal_zone_of_sensor_unregister(ts->dev, ts->tz);
 377
 378         /* Deactivate all IRQs */
 379         writel(0, ts->base + TP_INT_FIFOC);
 380
 381         return 0;
 382 }
 383
 384 static const struct of_device_id sun4i_ts_of_match[] = {
 385         { .compatible = "allwinner,sun4i-a10-ts", },
 386         { .compatible = "allwinner,sun6i-a31-ts", },
 387         { /* sentinel */ }
 388 };
 389 MODULE_DEVICE_TABLE(of, sun4i_ts_of_match);
 390
 391 static struct platform_driver sun4i_ts_driver = {
 392         .driver = {
 393                 .name   = "sun4i-ts",
 394                 .of_match_table = of_match_ptr(sun4i_ts_of_match),
 395         },
 396         .probe  = sun4i_ts_probe,
 397         .remove = sun4i_ts_remove,
 398 };
 399
 400 module_platform_driver(sun4i_ts_driver);
 401
 402 MODULE_DESCRIPTION("Allwinner sun4i resistive touchscreen controller driver");
 403 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 404 MODULE_LICENSE("GPL");