drivers/input/touchscreen/da9052_tsi.c

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