linux/drivers/input/touchscreen/sun4i-ts.c
<<
>>
Prefs
   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
 107struct 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
 116static 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
 146static 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
 164static 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
 175static 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
 183static 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
 195static 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
 201static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
 202static DEVICE_ATTR(temp1_label, S_IRUGO, show_temp_label, NULL);
 203
 204static struct attribute *sun4i_ts_attrs[] = {
 205        &dev_attr_temp1_input.attr,
 206        &dev_attr_temp1_label.attr,
 207        NULL
 208};
 209ATTRIBUTE_GROUPS(sun4i_ts);
 210
 211static 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
 305static 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
 319static const struct of_device_id sun4i_ts_of_match[] = {
 320        { .compatible = "allwinner,sun4i-a10-ts", },
 321        { /* sentinel */ }
 322};
 323MODULE_DEVICE_TABLE(of, sun4i_ts_of_match);
 324
 325static struct platform_driver sun4i_ts_driver = {
 326        .driver = {
 327                .name   = "sun4i-ts",
 328                .of_match_table = of_match_ptr(sun4i_ts_of_match),
 329        },
 330        .probe  = sun4i_ts_probe,
 331        .remove = sun4i_ts_remove,
 332};
 333
 334module_platform_driver(sun4i_ts_driver);
 335
 336MODULE_DESCRIPTION("Allwinner sun4i resistive touchscreen controller driver");
 337MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 338MODULE_LICENSE("GPL");
 339
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.