drivers/input/touchscreen/sun4i-ts.c

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This source file includes following definitions.
sun4i_ts_irq_handle_input
sun4i_ts_irq
sun4i_ts_open
sun4i_ts_close
sun4i_get_temp
sun4i_get_tz_temp
show_temp
show_temp_label
sun4i_ts_probe
sun4i_ts_remove
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Allwinner sunxi resistive touchscreen controller driver
   4  *
   5  * Copyright (C) 2013 - 2014 Hans de Goede <hdegoede@redhat.com>
   6  *
   7  * The hwmon parts are based on work by Corentin LABBE which is:
   8  * Copyright (C) 2013 Corentin LABBE <clabbe.montjoie@gmail.com>
   9  */
  10 
  11 /*
  12  * The sun4i-ts controller is capable of detecting a second touch, but when a
  13  * second touch is present then the accuracy becomes so bad the reported touch
  14  * location is not useable.
  15  *
  16  * The original android driver contains some complicated heuristics using the
  17  * aprox. distance between the 2 touches to see if the user is making a pinch
  18  * open / close movement, and then reports emulated multi-touch events around
  19  * the last touch coordinate (as the dual-touch coordinates are worthless).
  20  *
  21  * These kinds of heuristics are just asking for trouble (and don't belong
  22  * in the kernel). So this driver offers straight forward, reliable single
  23  * touch functionality only.
  24  *
  25  * s.a. A20 User Manual "1.15 TP" (Documentation/arm/sunxi.rst)
  26  * (looks like the description in the A20 User Manual v1.3 is better
  27  * than the one in the A10 User Manual v.1.5)
  28  */
  29 
  30 #include <linux/err.h>
  31 #include <linux/hwmon.h>
  32 #include <linux/thermal.h>
  33 #include <linux/init.h>
  34 #include <linux/input.h>
  35 #include <linux/interrupt.h>
  36 #include <linux/io.h>
  37 #include <linux/module.h>
  38 #include <linux/of_platform.h>
  39 #include <linux/platform_device.h>
  40 #include <linux/slab.h>
  41 
  42 #define TP_CTRL0                0x00
  43 #define TP_CTRL1                0x04
  44 #define TP_CTRL2                0x08
  45 #define TP_CTRL3                0x0c
  46 #define TP_INT_FIFOC            0x10
  47 #define TP_INT_FIFOS            0x14
  48 #define TP_TPR                  0x18
  49 #define TP_CDAT                 0x1c
  50 #define TEMP_DATA               0x20
  51 #define TP_DATA                 0x24
  52 
  53 /* TP_CTRL0 bits */
  54 #define ADC_FIRST_DLY(x)        ((x) << 24) /* 8 bits */
  55 #define ADC_FIRST_DLY_MODE(x)   ((x) << 23)
  56 #define ADC_CLK_SEL(x)          ((x) << 22)
  57 #define ADC_CLK_DIV(x)          ((x) << 20) /* 3 bits */
  58 #define FS_DIV(x)               ((x) << 16) /* 4 bits */
  59 #define T_ACQ(x)                ((x) << 0) /* 16 bits */
  60 
  61 /* TP_CTRL1 bits */
  62 #define STYLUS_UP_DEBOUN(x)     ((x) << 12) /* 8 bits */
  63 #define STYLUS_UP_DEBOUN_EN(x)  ((x) << 9)
  64 #define TOUCH_PAN_CALI_EN(x)    ((x) << 6)
  65 #define TP_DUAL_EN(x)           ((x) << 5)
  66 #define TP_MODE_EN(x)           ((x) << 4)
  67 #define TP_ADC_SELECT(x)        ((x) << 3)
  68 #define ADC_CHAN_SELECT(x)      ((x) << 0)  /* 3 bits */
  69 
  70 /* on sun6i, bits 3~6 are left shifted by 1 to 4~7 */
  71 #define SUN6I_TP_MODE_EN(x)     ((x) << 5)
  72 
  73 /* TP_CTRL2 bits */
  74 #define TP_SENSITIVE_ADJUST(x)  ((x) << 28) /* 4 bits */
  75 #define TP_MODE_SELECT(x)       ((x) << 26) /* 2 bits */
  76 #define PRE_MEA_EN(x)           ((x) << 24)
  77 #define PRE_MEA_THRE_CNT(x)     ((x) << 0) /* 24 bits */
  78 
  79 /* TP_CTRL3 bits */
  80 #define FILTER_EN(x)            ((x) << 2)
  81 #define FILTER_TYPE(x)          ((x) << 0)  /* 2 bits */
  82 
  83 /* TP_INT_FIFOC irq and fifo mask / control bits */
  84 #define TEMP_IRQ_EN(x)          ((x) << 18)
  85 #define OVERRUN_IRQ_EN(x)       ((x) << 17)
  86 #define DATA_IRQ_EN(x)          ((x) << 16)
  87 #define TP_DATA_XY_CHANGE(x)    ((x) << 13)
  88 #define FIFO_TRIG(x)            ((x) << 8)  /* 5 bits */
  89 #define DATA_DRQ_EN(x)          ((x) << 7)
  90 #define FIFO_FLUSH(x)           ((x) << 4)
  91 #define TP_UP_IRQ_EN(x)         ((x) << 1)
  92 #define TP_DOWN_IRQ_EN(x)       ((x) << 0)
  93 
  94 /* TP_INT_FIFOS irq and fifo status bits */
  95 #define TEMP_DATA_PENDING       BIT(18)
  96 #define FIFO_OVERRUN_PENDING    BIT(17)
  97 #define FIFO_DATA_PENDING       BIT(16)
  98 #define TP_IDLE_FLG             BIT(2)
  99 #define TP_UP_PENDING           BIT(1)
 100 #define TP_DOWN_PENDING         BIT(0)
 101 
 102 /* TP_TPR bits */
 103 #define TEMP_ENABLE(x)          ((x) << 16)
 104 #define TEMP_PERIOD(x)          ((x) << 0)  /* t = x * 256 * 16 / clkin */
 105 
 106 struct sun4i_ts_data {
 107         struct device *dev;
 108         struct input_dev *input;
 109         void __iomem *base;
 110         unsigned int irq;
 111         bool ignore_fifo_data;
 112         int temp_data;
 113         int temp_offset;
 114         int temp_step;
 115 };
 116 
 117 static void sun4i_ts_irq_handle_input(struct sun4i_ts_data *ts, u32 reg_val)
 118 {
 119         u32 x, y;
 120 
 121         if (reg_val & FIFO_DATA_PENDING) {
 122                 x = readl(ts->base + TP_DATA);
 123                 y = readl(ts->base + TP_DATA);
 124                 /* The 1st location reported after an up event is unreliable */
 125                 if (!ts->ignore_fifo_data) {
 126                         input_report_abs(ts->input, ABS_X, x);
 127                         input_report_abs(ts->input, ABS_Y, y);
 128                         /*
 129                          * The hardware has a separate down status bit, but
 130                          * that gets set before we get the first location,
 131                          * resulting in reporting a click on the old location.
 132                          */
 133                         input_report_key(ts->input, BTN_TOUCH, 1);
 134                         input_sync(ts->input);
 135                 } else {
 136                         ts->ignore_fifo_data = false;
 137                 }
 138         }
 139 
 140         if (reg_val & TP_UP_PENDING) {
 141                 ts->ignore_fifo_data = true;
 142                 input_report_key(ts->input, BTN_TOUCH, 0);
 143                 input_sync(ts->input);
 144         }
 145 }
 146 
 147 static irqreturn_t sun4i_ts_irq(int irq, void *dev_id)
 148 {
 149         struct sun4i_ts_data *ts = dev_id;
 150         u32 reg_val;
 151 
 152         reg_val  = readl(ts->base + TP_INT_FIFOS);
 153 
 154         if (reg_val & TEMP_DATA_PENDING)
 155                 ts->temp_data = readl(ts->base + TEMP_DATA);
 156 
 157         if (ts->input)
 158                 sun4i_ts_irq_handle_input(ts, reg_val);
 159 
 160         writel(reg_val, ts->base + TP_INT_FIFOS);
 161 
 162         return IRQ_HANDLED;
 163 }
 164 
 165 static int sun4i_ts_open(struct input_dev *dev)
 166 {
 167         struct sun4i_ts_data *ts = input_get_drvdata(dev);
 168 
 169         /* Flush, set trig level to 1, enable temp, data and up irqs */
 170         writel(TEMP_IRQ_EN(1) | DATA_IRQ_EN(1) | FIFO_TRIG(1) | FIFO_FLUSH(1) |
 171                 TP_UP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
 172 
 173         return 0;
 174 }
 175 
 176 static void sun4i_ts_close(struct input_dev *dev)
 177 {
 178         struct sun4i_ts_data *ts = input_get_drvdata(dev);
 179 
 180         /* Deactivate all input IRQs */
 181         writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
 182 }
 183 
 184 static int sun4i_get_temp(const struct sun4i_ts_data *ts, int *temp)
 185 {
 186         /* No temp_data until the first irq */
 187         if (ts->temp_data == -1)
 188                 return -EAGAIN;
 189 
 190         *temp = ts->temp_data * ts->temp_step - ts->temp_offset;
 191 
 192         return 0;
 193 }
 194 
 195 static int sun4i_get_tz_temp(void *data, int *temp)
 196 {
 197         return sun4i_get_temp(data, temp);
 198 }
 199 
 200 static const struct thermal_zone_of_device_ops sun4i_ts_tz_ops = {
 201         .get_temp = sun4i_get_tz_temp,
 202 };
 203 
 204 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 205                          char *buf)
 206 {
 207         struct sun4i_ts_data *ts = dev_get_drvdata(dev);
 208         int temp;
 209         int error;
 210 
 211         error = sun4i_get_temp(ts, &temp);
 212         if (error)
 213                 return error;
 214 
 215         return sprintf(buf, "%d\n", temp);
 216 }
 217 
 218 static ssize_t show_temp_label(struct device *dev,
 219                               struct device_attribute *devattr, char *buf)
 220 {
 221         return sprintf(buf, "SoC temperature\n");
 222 }
 223 
 224 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
 225 static DEVICE_ATTR(temp1_label, S_IRUGO, show_temp_label, NULL);
 226 
 227 static struct attribute *sun4i_ts_attrs[] = {
 228         &dev_attr_temp1_input.attr,
 229         &dev_attr_temp1_label.attr,
 230         NULL
 231 };
 232 ATTRIBUTE_GROUPS(sun4i_ts);
 233 
 234 static int sun4i_ts_probe(struct platform_device *pdev)
 235 {
 236         struct sun4i_ts_data *ts;
 237         struct device *dev = &pdev->dev;
 238         struct device_node *np = dev->of_node;
 239         struct device *hwmon;
 240         struct thermal_zone_device *thermal;
 241         int error;
 242         u32 reg;
 243         bool ts_attached;
 244         u32 tp_sensitive_adjust = 15;
 245         u32 filter_type = 1;
 246 
 247         ts = devm_kzalloc(dev, sizeof(struct sun4i_ts_data), GFP_KERNEL);
 248         if (!ts)
 249                 return -ENOMEM;
 250 
 251         ts->dev = dev;
 252         ts->ignore_fifo_data = true;
 253         ts->temp_data = -1;
 254         if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts")) {
 255                 /* Allwinner SDK has temperature (C) = (value / 6) - 271 */
 256                 ts->temp_offset = 271000;
 257                 ts->temp_step = 167;
 258         } else if (of_device_is_compatible(np, "allwinner,sun4i-a10-ts")) {
 259                 /*
 260                  * The A10 temperature sensor has quite a wide spread, these
 261                  * parameters are based on the averaging of the calibration
 262                  * results of 4 completely different boards, with a spread of
 263                  * temp_step from 0.096 - 0.170 and temp_offset from 176 - 331.
 264                  */
 265                 ts->temp_offset = 257000;
 266                 ts->temp_step = 133;
 267         } else {
 268                 /*
 269                  * The user manuals do not contain the formula for calculating
 270                  * the temperature. The formula used here is from the AXP209,
 271                  * which is designed by X-Powers, an affiliate of Allwinner:
 272                  *
 273                  *     temperature (C) = (value * 0.1) - 144.7
 274                  *
 275                  * Allwinner does not have any documentation whatsoever for
 276                  * this hardware. Moreover, it is claimed that the sensor
 277                  * is inaccurate and cannot work properly.
 278                  */
 279                 ts->temp_offset = 144700;
 280                 ts->temp_step = 100;
 281         }
 282 
 283         ts_attached = of_property_read_bool(np, "allwinner,ts-attached");
 284         if (ts_attached) {
 285                 ts->input = devm_input_allocate_device(dev);
 286                 if (!ts->input)
 287                         return -ENOMEM;
 288 
 289                 ts->input->name = pdev->name;
 290                 ts->input->phys = "sun4i_ts/input0";
 291                 ts->input->open = sun4i_ts_open;
 292                 ts->input->close = sun4i_ts_close;
 293                 ts->input->id.bustype = BUS_HOST;
 294                 ts->input->id.vendor = 0x0001;
 295                 ts->input->id.product = 0x0001;
 296                 ts->input->id.version = 0x0100;
 297                 ts->input->evbit[0] =  BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);
 298                 __set_bit(BTN_TOUCH, ts->input->keybit);
 299                 input_set_abs_params(ts->input, ABS_X, 0, 4095, 0, 0);
 300                 input_set_abs_params(ts->input, ABS_Y, 0, 4095, 0, 0);
 301                 input_set_drvdata(ts->input, ts);
 302         }
 303 
 304         ts->base = devm_platform_ioremap_resource(pdev, 0);
 305         if (IS_ERR(ts->base))
 306                 return PTR_ERR(ts->base);
 307 
 308         ts->irq = platform_get_irq(pdev, 0);
 309         error = devm_request_irq(dev, ts->irq, sun4i_ts_irq, 0, "sun4i-ts", ts);
 310         if (error)
 311                 return error;
 312 
 313         /*
 314          * Select HOSC clk, clkin = clk / 6, adc samplefreq = clkin / 8192,
 315          * t_acq = clkin / (16 * 64)
 316          */
 317         writel(ADC_CLK_SEL(0) | ADC_CLK_DIV(2) | FS_DIV(7) | T_ACQ(63),
 318                ts->base + TP_CTRL0);
 319 
 320         /*
 321          * tp_sensitive_adjust is an optional property
 322          * tp_mode = 0 : only x and y coordinates, as we don't use dual touch
 323          */
 324         of_property_read_u32(np, "allwinner,tp-sensitive-adjust",
 325                              &tp_sensitive_adjust);
 326         writel(TP_SENSITIVE_ADJUST(tp_sensitive_adjust) | TP_MODE_SELECT(0),
 327                ts->base + TP_CTRL2);
 328 
 329         /*
 330          * Enable median and averaging filter, optional property for
 331          * filter type.
 332          */
 333         of_property_read_u32(np, "allwinner,filter-type", &filter_type);
 334         writel(FILTER_EN(1) | FILTER_TYPE(filter_type), ts->base + TP_CTRL3);
 335 
 336         /* Enable temperature measurement, period 1953 (2 seconds) */
 337         writel(TEMP_ENABLE(1) | TEMP_PERIOD(1953), ts->base + TP_TPR);
 338 
 339         /*
 340          * Set stylus up debounce to aprox 10 ms, enable debounce, and
 341          * finally enable tp mode.
 342          */
 343         reg = STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1);
 344         if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts"))
 345                 reg |= SUN6I_TP_MODE_EN(1);
 346         else
 347                 reg |= TP_MODE_EN(1);
 348         writel(reg, ts->base + TP_CTRL1);
 349 
 350         /*
 351          * The thermal core does not register hwmon devices for DT-based
 352          * thermal zone sensors, such as this one.
 353          */
 354         hwmon = devm_hwmon_device_register_with_groups(ts->dev, "sun4i_ts",
 355                                                        ts, sun4i_ts_groups);
 356         if (IS_ERR(hwmon))
 357                 return PTR_ERR(hwmon);
 358 
 359         thermal = devm_thermal_zone_of_sensor_register(ts->dev, 0, ts,
 360                                                        &sun4i_ts_tz_ops);
 361         if (IS_ERR(thermal))
 362                 return PTR_ERR(thermal);
 363 
 364         writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
 365 
 366         if (ts_attached) {
 367                 error = input_register_device(ts->input);
 368                 if (error) {
 369                         writel(0, ts->base + TP_INT_FIFOC);
 370                         return error;
 371                 }
 372         }
 373 
 374         platform_set_drvdata(pdev, ts);
 375         return 0;
 376 }
 377 
 378 static int sun4i_ts_remove(struct platform_device *pdev)
 379 {
 380         struct sun4i_ts_data *ts = platform_get_drvdata(pdev);
 381 
 382         /* Explicit unregister to avoid open/close changing the imask later */
 383         if (ts->input)
 384                 input_unregister_device(ts->input);
 385 
 386         /* Deactivate all IRQs */
 387         writel(0, ts->base + TP_INT_FIFOC);
 388 
 389         return 0;
 390 }
 391 
 392 static const struct of_device_id sun4i_ts_of_match[] = {
 393         { .compatible = "allwinner,sun4i-a10-ts", },
 394         { .compatible = "allwinner,sun5i-a13-ts", },
 395         { .compatible = "allwinner,sun6i-a31-ts", },
 396         { /* sentinel */ }
 397 };
 398 MODULE_DEVICE_TABLE(of, sun4i_ts_of_match);
 399 
 400 static struct platform_driver sun4i_ts_driver = {
 401         .driver = {
 402                 .name   = "sun4i-ts",
 403                 .of_match_table = of_match_ptr(sun4i_ts_of_match),
 404         },
 405         .probe  = sun4i_ts_probe,
 406         .remove = sun4i_ts_remove,
 407 };
 408 
 409 module_platform_driver(sun4i_ts_driver);
 410 
 411 MODULE_DESCRIPTION("Allwinner sun4i resistive touchscreen controller driver");
 412 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 413 MODULE_LICENSE("GPL");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/input/touchscreen/sun4i-ts.c

DEFINITIONS
