linux/drivers/input/touchscreen/da9052_tsi.c
<<
>>
Prefs
   1/*
   2 * TSI driver for Dialog DA9052
   3 *
   4 * Copyright(c) 2012 Dialog Semiconductor Ltd.
   5 *
   6 * Author: David Dajun Chen <dchen@diasemi.com>
   7 *
   8 *  This program is free software; you can redistribute  it and/or modify it
   9 *  under  the terms of  the GNU General  Public License as published by the
  10 *  Free Software Foundation;  either version 2 of the  License, or (at your
  11 *  option) any later version.
  12 *
  13 */
  14#include <linux/module.h>
  15#include <linux/input.h>
  16#include <linux/delay.h>
  17#include <linux/platform_device.h>
  18#include <linux/interrupt.h>
  19
  20#include <linux/mfd/da9052/reg.h>
  21#include <linux/mfd/da9052/da9052.h>
  22
  23#define TSI_PEN_DOWN_STATUS 0x40
  24
  25struct da9052_tsi {
  26        struct da9052 *da9052;
  27        struct input_dev *dev;
  28        struct delayed_work ts_pen_work;
  29        struct mutex mutex;
  30        bool stopped;
  31        bool adc_on;
  32};
  33
  34static void da9052_ts_adc_toggle(struct da9052_tsi *tsi, bool on)
  35{
  36        da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0, on);
  37        tsi->adc_on = on;
  38}
  39
  40static irqreturn_t da9052_ts_pendwn_irq(int irq, void *data)
  41{
  42        struct da9052_tsi *tsi = data;
  43
  44        if (!tsi->stopped) {
  45                /* Mask PEN_DOWN event and unmask TSI_READY event */
  46                da9052_disable_irq_nosync(tsi->da9052, DA9052_IRQ_PENDOWN);
  47                da9052_enable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
  48
  49                da9052_ts_adc_toggle(tsi, true);
  50
  51                schedule_delayed_work(&tsi->ts_pen_work, HZ / 50);
  52        }
  53
  54        return IRQ_HANDLED;
  55}
  56
  57static void da9052_ts_read(struct da9052_tsi *tsi)
  58{
  59        struct input_dev *input = tsi->dev;
  60        int ret;
  61        u16 x, y, z;
  62        u8 v;
  63
  64        ret = da9052_reg_read(tsi->da9052, DA9052_TSI_X_MSB_REG);
  65        if (ret < 0)
  66                return;
  67
  68        x = (u16) ret;
  69
  70        ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Y_MSB_REG);
  71        if (ret < 0)
  72                return;
  73
  74        y = (u16) ret;
  75
  76        ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Z_MSB_REG);
  77        if (ret < 0)
  78                return;
  79
  80        z = (u16) ret;
  81
  82        ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
  83        if (ret < 0)
  84                return;
  85
  86        v = (u8) ret;
  87
  88        x = ((x << 2) & 0x3fc) | (v & 0x3);
  89        y = ((y << 2) & 0x3fc) | ((v & 0xc) >> 2);
  90        z = ((z << 2) & 0x3fc) | ((v & 0x30) >> 4);
  91
  92        input_report_key(input, BTN_TOUCH, 1);
  93        input_report_abs(input, ABS_X, x);
  94        input_report_abs(input, ABS_Y, y);
  95        input_report_abs(input, ABS_PRESSURE, z);
  96        input_sync(input);
  97}
  98
  99static irqreturn_t da9052_ts_datardy_irq(int irq, void *data)
 100{
 101        struct da9052_tsi *tsi = data;
 102
 103        da9052_ts_read(tsi);
 104
 105        return IRQ_HANDLED;
 106}
 107
 108static void da9052_ts_pen_work(struct work_struct *work)
 109{
 110        struct da9052_tsi *tsi = container_of(work, struct da9052_tsi,
 111                                              ts_pen_work.work);
 112        if (!tsi->stopped) {
 113                int ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
 114                if (ret < 0 || (ret & TSI_PEN_DOWN_STATUS)) {
 115                        /* Pen is still DOWN (or read error) */
 116                        schedule_delayed_work(&tsi->ts_pen_work, HZ / 50);
 117                } else {
 118                        struct input_dev *input = tsi->dev;
 119
 120                        /* Pen UP */
 121                        da9052_ts_adc_toggle(tsi, false);
 122
 123                        /* Report Pen UP */
 124                        input_report_key(input, BTN_TOUCH, 0);
 125                        input_report_abs(input, ABS_PRESSURE, 0);
 126                        input_sync(input);
 127
 128                        /*
 129                         * FIXME: Fixes the unhandled irq issue when quick
 130                         * pen down and pen up events occurs
 131                         */
 132                        ret = da9052_reg_update(tsi->da9052,
 133                                                DA9052_EVENT_B_REG, 0xC0, 0xC0);
 134                        if (ret < 0)
 135                                return;
 136
 137                        /* Mask TSI_READY event and unmask PEN_DOWN event */
 138                        da9052_disable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
 139                        da9052_enable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
 140                }
 141        }
 142}
 143
 144static int da9052_ts_configure_gpio(struct da9052 *da9052)
 145{
 146        int error;
 147
 148        error = da9052_reg_update(da9052, DA9052_GPIO_2_3_REG, 0x30, 0);
 149        if (error < 0)
 150                return error;
 151
 152        error = da9052_reg_update(da9052, DA9052_GPIO_4_5_REG, 0x33, 0);
 153        if (error < 0)
 154                return error;
 155
 156        error = da9052_reg_update(da9052, DA9052_GPIO_6_7_REG, 0x33, 0);
 157        if (error < 0)
 158                return error;
 159
 160        return 0;
 161}
 162
 163static int da9052_configure_tsi(struct da9052_tsi *tsi)
 164{
 165        int error;
 166
 167        error = da9052_ts_configure_gpio(tsi->da9052);
 168        if (error)
 169                return error;
 170
 171        /* Measure TSI sample every 1ms */
 172        error = da9052_reg_update(tsi->da9052, DA9052_ADC_CONT_REG,
 173                                  1 << 6, 1 << 6);
 174        if (error < 0)
 175                return error;
 176
 177        /* TSI_DELAY: 3 slots, TSI_SKIP: 0 slots, TSI_MODE: XYZP */
 178        error = da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 0xFC, 0xC0);
 179        if (error < 0)
 180                return error;
 181
 182        /* Supply TSIRef through LD09 */
 183        error = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x59);
 184        if (error < 0)
 185                return error;
 186
 187        return 0;
 188}
 189
 190static int da9052_ts_input_open(struct input_dev *input_dev)
 191{
 192        struct da9052_tsi *tsi = input_get_drvdata(input_dev);
 193
 194        tsi->stopped = false;
 195        mb();
 196
 197        /* Unmask PEN_DOWN event */
 198        da9052_enable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
 199
 200        /* Enable Pen Detect Circuit */
 201        return da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG,
 202                                 1 << 1, 1 << 1);
 203}
 204
 205static void da9052_ts_input_close(struct input_dev *input_dev)
 206{
 207        struct da9052_tsi *tsi = input_get_drvdata(input_dev);
 208
 209        tsi->stopped = true;
 210        mb();
 211        da9052_disable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
 212        cancel_delayed_work_sync(&tsi->ts_pen_work);
 213
 214        if (tsi->adc_on) {
 215                da9052_disable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
 216                da9052_ts_adc_toggle(tsi, false);
 217
 218                /*
 219                 * If ADC was on that means that pendwn IRQ was disabled
 220                 * twice and we need to enable it to keep enable/disable
 221                 * counter balanced. IRQ is still off though.
 222                 */
 223                da9052_enable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
 224        }
 225
 226        /* Disable Pen Detect Circuit */
 227        da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 1, 0);
 228}
 229
 230static int da9052_ts_probe(struct platform_device *pdev)
 231{
 232        struct da9052 *da9052;
 233        struct da9052_tsi *tsi;
 234        struct input_dev *input_dev;
 235        int error;
 236
 237        da9052 = dev_get_drvdata(pdev->dev.parent);
 238        if (!da9052)
 239                return -EINVAL;
 240
 241        tsi = kzalloc(sizeof(struct da9052_tsi), GFP_KERNEL);
 242        input_dev = input_allocate_device();
 243        if (!tsi || !input_dev) {
 244                error = -ENOMEM;
 245                goto err_free_mem;
 246        }
 247
 248        tsi->da9052 = da9052;
 249        tsi->dev = input_dev;
 250        tsi->stopped = true;
 251        INIT_DELAYED_WORK(&tsi->ts_pen_work, da9052_ts_pen_work);
 252
 253        input_dev->id.version = 0x0101;
 254        input_dev->id.vendor = 0x15B6;
 255        input_dev->id.product = 0x9052;
 256        input_dev->name = "Dialog DA9052 TouchScreen Driver";
 257        input_dev->dev.parent = &pdev->dev;
 258        input_dev->open = da9052_ts_input_open;
 259        input_dev->close = da9052_ts_input_close;
 260
 261        __set_bit(EV_ABS, input_dev->evbit);
 262        __set_bit(EV_KEY, input_dev->evbit);
 263        __set_bit(BTN_TOUCH, input_dev->keybit);
 264
 265        input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
 266        input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
 267        input_set_abs_params(input_dev, ABS_PRESSURE, 0, 1023, 0, 0);
 268
 269        input_set_drvdata(input_dev, tsi);
 270
 271        /* Disable Pen Detect Circuit */
 272        da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 1, 0);
 273
 274        /* Disable ADC */
 275        da9052_ts_adc_toggle(tsi, false);
 276
 277        error = da9052_request_irq(tsi->da9052, DA9052_IRQ_PENDOWN,
 278                                "pendown-irq", da9052_ts_pendwn_irq, tsi);
 279        if (error) {
 280                dev_err(tsi->da9052->dev,
 281                        "Failed to register PENDWN IRQ: %d\n", error);
 282                goto err_free_mem;
 283        }
 284
 285        error = da9052_request_irq(tsi->da9052, DA9052_IRQ_TSIREADY,
 286                                "tsiready-irq", da9052_ts_datardy_irq, tsi);
 287        if (error) {
 288                dev_err(tsi->da9052->dev,
 289                        "Failed to register TSIRDY IRQ :%d\n", error);
 290                goto err_free_pendwn_irq;
 291        }
 292
 293        /* Mask PEN_DOWN and TSI_READY events */
 294        da9052_disable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
 295        da9052_disable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
 296
 297        error = da9052_configure_tsi(tsi);
 298        if (error)
 299                goto err_free_datardy_irq;
 300
 301        error = input_register_device(tsi->dev);
 302        if (error)
 303                goto err_free_datardy_irq;
 304
 305        platform_set_drvdata(pdev, tsi);
 306
 307        return 0;
 308
 309err_free_datardy_irq:
 310        da9052_free_irq(tsi->da9052, DA9052_IRQ_TSIREADY, tsi);
 311err_free_pendwn_irq:
 312        da9052_free_irq(tsi->da9052, DA9052_IRQ_PENDOWN, tsi);
 313err_free_mem:
 314        kfree(tsi);
 315        input_free_device(input_dev);
 316
 317        return error;
 318}
 319
 320static int  da9052_ts_remove(struct platform_device *pdev)
 321{
 322        struct da9052_tsi *tsi = platform_get_drvdata(pdev);
 323
 324        da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
 325
 326        da9052_free_irq(tsi->da9052, DA9052_IRQ_TSIREADY, tsi);
 327        da9052_free_irq(tsi->da9052, DA9052_IRQ_PENDOWN, tsi);
 328
 329        input_unregister_device(tsi->dev);
 330        kfree(tsi);
 331
 332        return 0;
 333}
 334
 335static struct platform_driver da9052_tsi_driver = {
 336        .probe  = da9052_ts_probe,
 337        .remove = da9052_ts_remove,
 338        .driver = {
 339                .name   = "da9052-tsi",
 340        },
 341};
 342
 343module_platform_driver(da9052_tsi_driver);
 344
 345MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9052");
 346MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
 347MODULE_LICENSE("GPL");
 348MODULE_ALIAS("platform:da9052-tsi");
 349