drivers/input/touchscreen/da9052_tsi.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * TSI driver for Dialog DA9052
   4  *
   5  * Copyright(c) 2012 Dialog Semiconductor Ltd.
   6  *
   7  * Author: David Dajun Chen <dchen@diasemi.com>
   8  */
   9 #include <linux/module.h>
  10 #include <linux/input.h>
  11 #include <linux/delay.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/interrupt.h>
  14
  15 #include <linux/mfd/da9052/reg.h>
  16 #include <linux/mfd/da9052/da9052.h>
  17
  18 #define TSI_PEN_DOWN_STATUS 0x40
  19
  20 struct da9052_tsi {
  21         struct da9052 *da9052;
  22         struct input_dev *dev;
  23         struct delayed_work ts_pen_work;
  24         bool stopped;
  25         bool adc_on;
  26 };
  27
  28 static void da9052_ts_adc_toggle(struct da9052_tsi *tsi, bool on)
  29 {
  30         da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0, on);
  31         tsi->adc_on = on;
  32 }
  33
  34 static irqreturn_t da9052_ts_pendwn_irq(int irq, void *data)
  35 {
  36         struct da9052_tsi *tsi = data;
  37
  38         if (!tsi->stopped) {
  39                 /* Mask PEN_DOWN event and unmask TSI_READY event */
  40                 da9052_disable_irq_nosync(tsi->da9052, DA9052_IRQ_PENDOWN);
  41                 da9052_enable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
  42
  43                 da9052_ts_adc_toggle(tsi, true);
  44
  45                 schedule_delayed_work(&tsi->ts_pen_work, HZ / 50);
  46         }
  47
  48         return IRQ_HANDLED;
  49 }
  50
  51 static void da9052_ts_read(struct da9052_tsi *tsi)
  52 {
  53         struct input_dev *input = tsi->dev;
  54         int ret;
  55         u16 x, y, z;
  56         u8 v;
  57
  58         ret = da9052_reg_read(tsi->da9052, DA9052_TSI_X_MSB_REG);
  59         if (ret < 0)
  60                 return;
  61
  62         x = (u16) ret;
  63
  64         ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Y_MSB_REG);
  65         if (ret < 0)
  66                 return;
  67
  68         y = (u16) ret;
  69
  70         ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Z_MSB_REG);
  71         if (ret < 0)
  72                 return;
  73
  74         z = (u16) ret;
  75
  76         ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
  77         if (ret < 0)
  78                 return;
  79
  80         v = (u8) ret;
  81
  82         x = ((x << 2) & 0x3fc) | (v & 0x3);
  83         y = ((y << 2) & 0x3fc) | ((v & 0xc) >> 2);
  84         z = ((z << 2) & 0x3fc) | ((v & 0x30) >> 4);
  85
  86         input_report_key(input, BTN_TOUCH, 1);
  87         input_report_abs(input, ABS_X, x);
  88         input_report_abs(input, ABS_Y, y);
  89         input_report_abs(input, ABS_PRESSURE, z);
  90         input_sync(input);
  91 }
  92
  93 static irqreturn_t da9052_ts_datardy_irq(int irq, void *data)
  94 {
  95         struct da9052_tsi *tsi = data;
  96
  97         da9052_ts_read(tsi);
  98
  99         return IRQ_HANDLED;
 100 }
 101
 102 static void da9052_ts_pen_work(struct work_struct *work)
 103 {
 104         struct da9052_tsi *tsi = container_of(work, struct da9052_tsi,
 105                                               ts_pen_work.work);
 106         if (!tsi->stopped) {
 107                 int ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
 108                 if (ret < 0 || (ret & TSI_PEN_DOWN_STATUS)) {
 109                         /* Pen is still DOWN (or read error) */
 110                         schedule_delayed_work(&tsi->ts_pen_work, HZ / 50);
 111                 } else {
 112                         struct input_dev *input = tsi->dev;
 113
 114                         /* Pen UP */
 115                         da9052_ts_adc_toggle(tsi, false);
 116
 117                         /* Report Pen UP */
 118                         input_report_key(input, BTN_TOUCH, 0);
 119                         input_report_abs(input, ABS_PRESSURE, 0);
 120                         input_sync(input);
 121
 122                         /*
 123                          * FIXME: Fixes the unhandled irq issue when quick
 124                          * pen down and pen up events occurs
 125                          */
 126                         ret = da9052_reg_update(tsi->da9052,
 127                                                 DA9052_EVENT_B_REG, 0xC0, 0xC0);
 128                         if (ret < 0)
 129                                 return;
 130
 131                         /* Mask TSI_READY event and unmask PEN_DOWN event */
 132                         da9052_disable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
 133                         da9052_enable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
 134                 }
 135         }
 136 }
 137
 138 static int da9052_ts_configure_gpio(struct da9052 *da9052)
 139 {
 140         int error;
 141
 142         error = da9052_reg_update(da9052, DA9052_GPIO_2_3_REG, 0x30, 0);
 143         if (error < 0)
 144                 return error;
 145
 146         error = da9052_reg_update(da9052, DA9052_GPIO_4_5_REG, 0x33, 0);
 147         if (error < 0)
 148                 return error;
 149
 150         error = da9052_reg_update(da9052, DA9052_GPIO_6_7_REG, 0x33, 0);
 151         if (error < 0)
 152                 return error;
 153
 154         return 0;
 155 }
 156
 157 static int da9052_configure_tsi(struct da9052_tsi *tsi)
 158 {
 159         int error;
 160
 161         error = da9052_ts_configure_gpio(tsi->da9052);
 162         if (error)
 163                 return error;
 164
 165         /* Measure TSI sample every 1ms */
 166         error = da9052_reg_update(tsi->da9052, DA9052_ADC_CONT_REG,
 167                                   1 << 6, 1 << 6);
 168         if (error < 0)
 169                 return error;
 170
 171         /* TSI_DELAY: 3 slots, TSI_SKIP: 0 slots, TSI_MODE: XYZP */
 172         error = da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 0xFC, 0xC0);
 173         if (error < 0)
 174                 return error;
 175
 176         /* Supply TSIRef through LD09 */
 177         error = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x59);
 178         if (error < 0)
 179                 return error;
 180
 181         return 0;
 182 }
 183
 184 static int da9052_ts_input_open(struct input_dev *input_dev)
 185 {
 186         struct da9052_tsi *tsi = input_get_drvdata(input_dev);
 187
 188         tsi->stopped = false;
 189         mb();
 190
 191         /* Unmask PEN_DOWN event */
 192         da9052_enable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
 193
 194         /* Enable Pen Detect Circuit */
 195         return da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG,
 196                                  1 << 1, 1 << 1);
 197 }
 198
 199 static void da9052_ts_input_close(struct input_dev *input_dev)
 200 {
 201         struct da9052_tsi *tsi = input_get_drvdata(input_dev);
 202
 203         tsi->stopped = true;
 204         mb();
 205         da9052_disable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
 206         cancel_delayed_work_sync(&tsi->ts_pen_work);
 207
 208         if (tsi->adc_on) {
 209                 da9052_disable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
 210                 da9052_ts_adc_toggle(tsi, false);
 211
 212                 /*
 213                  * If ADC was on that means that pendwn IRQ was disabled
 214                  * twice and we need to enable it to keep enable/disable
 215                  * counter balanced. IRQ is still off though.
 216                  */
 217                 da9052_enable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
 218         }
 219
 220         /* Disable Pen Detect Circuit */
 221         da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 1, 0);
 222 }
 223
 224 static int da9052_ts_probe(struct platform_device *pdev)
 225 {
 226         struct da9052 *da9052;
 227         struct da9052_tsi *tsi;
 228         struct input_dev *input_dev;
 229         int error;
 230
 231         da9052 = dev_get_drvdata(pdev->dev.parent);
 232         if (!da9052)
 233                 return -EINVAL;
 234
 235         tsi = kzalloc(sizeof(struct da9052_tsi), GFP_KERNEL);
 236         input_dev = input_allocate_device();
 237         if (!tsi || !input_dev) {
 238                 error = -ENOMEM;
 239                 goto err_free_mem;
 240         }
 241
 242         tsi->da9052 = da9052;
 243         tsi->dev = input_dev;
 244         tsi->stopped = true;
 245         INIT_DELAYED_WORK(&tsi->ts_pen_work, da9052_ts_pen_work);
 246
 247         input_dev->id.version = 0x0101;
 248         input_dev->id.vendor = 0x15B6;
 249         input_dev->id.product = 0x9052;
 250         input_dev->name = "Dialog DA9052 TouchScreen Driver";
 251         input_dev->dev.parent = &pdev->dev;
 252         input_dev->open = da9052_ts_input_open;
 253         input_dev->close = da9052_ts_input_close;
 254
 255         __set_bit(EV_ABS, input_dev->evbit);
 256         __set_bit(EV_KEY, input_dev->evbit);
 257         __set_bit(BTN_TOUCH, input_dev->keybit);
 258
 259         input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
 260         input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
 261         input_set_abs_params(input_dev, ABS_PRESSURE, 0, 1023, 0, 0);
 262
 263         input_set_drvdata(input_dev, tsi);
 264
 265         /* Disable Pen Detect Circuit */
 266         da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 1, 0);
 267
 268         /* Disable ADC */
 269         da9052_ts_adc_toggle(tsi, false);
 270
 271         error = da9052_request_irq(tsi->da9052, DA9052_IRQ_PENDOWN,
 272                                 "pendown-irq", da9052_ts_pendwn_irq, tsi);
 273         if (error) {
 274                 dev_err(tsi->da9052->dev,
 275                         "Failed to register PENDWN IRQ: %d\n", error);
 276                 goto err_free_mem;
 277         }
 278
 279         error = da9052_request_irq(tsi->da9052, DA9052_IRQ_TSIREADY,
 280                                 "tsiready-irq", da9052_ts_datardy_irq, tsi);
 281         if (error) {
 282                 dev_err(tsi->da9052->dev,
 283                         "Failed to register TSIRDY IRQ :%d\n", error);
 284                 goto err_free_pendwn_irq;
 285         }
 286
 287         /* Mask PEN_DOWN and TSI_READY events */
 288         da9052_disable_irq(tsi->da9052, DA9052_IRQ_PENDOWN);
 289         da9052_disable_irq(tsi->da9052, DA9052_IRQ_TSIREADY);
 290
 291         error = da9052_configure_tsi(tsi);
 292         if (error)
 293                 goto err_free_datardy_irq;
 294
 295         error = input_register_device(tsi->dev);
 296         if (error)
 297                 goto err_free_datardy_irq;
 298
 299         platform_set_drvdata(pdev, tsi);
 300
 301         return 0;
 302
 303 err_free_datardy_irq:
 304         da9052_free_irq(tsi->da9052, DA9052_IRQ_TSIREADY, tsi);
 305 err_free_pendwn_irq:
 306         da9052_free_irq(tsi->da9052, DA9052_IRQ_PENDOWN, tsi);
 307 err_free_mem:
 308         kfree(tsi);
 309         input_free_device(input_dev);
 310
 311         return error;
 312 }
 313
 314 static int  da9052_ts_remove(struct platform_device *pdev)
 315 {
 316         struct da9052_tsi *tsi = platform_get_drvdata(pdev);
 317
 318         da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
 319
 320         da9052_free_irq(tsi->da9052, DA9052_IRQ_TSIREADY, tsi);
 321         da9052_free_irq(tsi->da9052, DA9052_IRQ_PENDOWN, tsi);
 322
 323         input_unregister_device(tsi->dev);
 324         kfree(tsi);
 325
 326         return 0;
 327 }
 328
 329 static struct platform_driver da9052_tsi_driver = {
 330         .probe  = da9052_ts_probe,
 331         .remove = da9052_ts_remove,
 332         .driver = {
 333                 .name   = "da9052-tsi",
 334         },
 335 };
 336
 337 module_platform_driver(da9052_tsi_driver);
 338
 339 MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9052");
 340 MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
 341 MODULE_LICENSE("GPL");
 342 MODULE_ALIAS("platform:da9052-tsi");