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         struct mutex mutex;
  30         bool stopped;
  31         bool adc_on;
  32 };
  33
  34 static 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
  40 static 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
  57 static 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
  99 static 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
 108 static 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
 144 static 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
 163 static 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
 190 static 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
 205 static 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
 230 static 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
 309 err_free_datardy_irq:
 310         da9052_free_irq(tsi->da9052, DA9052_IRQ_TSIREADY, tsi);
 311 err_free_pendwn_irq:
 312         da9052_free_irq(tsi->da9052, DA9052_IRQ_PENDOWN, tsi);
 313 err_free_mem:
 314         kfree(tsi);
 315         input_free_device(input_dev);
 316
 317         return error;
 318 }
 319
 320 static 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
 335 static 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
 343 module_platform_driver(da9052_tsi_driver);
 344
 345 MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9052");
 346 MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
 347 MODULE_LICENSE("GPL");
 348 MODULE_ALIAS("platform:da9052-tsi");