1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Touchscreen driver for WM831x PMICs 4 * 5 * Copyright 2011 Wolfson Microelectronics plc. 6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> 7 */ 8 9 #include <linux/module.h> 10 #include <linux/moduleparam.h> 11 #include <linux/kernel.h> 12 #include <linux/string.h> 13 #include <linux/pm.h> 14 #include <linux/input.h> 15 #include <linux/interrupt.h> 16 #include <linux/io.h> 17 #include <linux/mfd/wm831x/core.h> 18 #include <linux/mfd/wm831x/irq.h> 19 #include <linux/mfd/wm831x/pdata.h> 20 #include <linux/platform_device.h> 21 #include <linux/slab.h> 22 #include <linux/types.h> 23 24 /* 25 * R16424 (0x4028) - Touch Control 1 26 */ 27 #define WM831X_TCH_ENA 0x8000 /* TCH_ENA */ 28 #define WM831X_TCH_CVT_ENA 0x4000 /* TCH_CVT_ENA */ 29 #define WM831X_TCH_SLPENA 0x1000 /* TCH_SLPENA */ 30 #define WM831X_TCH_Z_ENA 0x0400 /* TCH_Z_ENA */ 31 #define WM831X_TCH_Y_ENA 0x0200 /* TCH_Y_ENA */ 32 #define WM831X_TCH_X_ENA 0x0100 /* TCH_X_ENA */ 33 #define WM831X_TCH_DELAY_MASK 0x00E0 /* TCH_DELAY - [7:5] */ 34 #define WM831X_TCH_DELAY_SHIFT 5 /* TCH_DELAY - [7:5] */ 35 #define WM831X_TCH_DELAY_WIDTH 3 /* TCH_DELAY - [7:5] */ 36 #define WM831X_TCH_RATE_MASK 0x001F /* TCH_RATE - [4:0] */ 37 #define WM831X_TCH_RATE_SHIFT 0 /* TCH_RATE - [4:0] */ 38 #define WM831X_TCH_RATE_WIDTH 5 /* TCH_RATE - [4:0] */ 39 40 /* 41 * R16425 (0x4029) - Touch Control 2 42 */ 43 #define WM831X_TCH_PD_WK 0x2000 /* TCH_PD_WK */ 44 #define WM831X_TCH_5WIRE 0x1000 /* TCH_5WIRE */ 45 #define WM831X_TCH_PDONLY 0x0800 /* TCH_PDONLY */ 46 #define WM831X_TCH_ISEL 0x0100 /* TCH_ISEL */ 47 #define WM831X_TCH_RPU_MASK 0x000F /* TCH_RPU - [3:0] */ 48 #define WM831X_TCH_RPU_SHIFT 0 /* TCH_RPU - [3:0] */ 49 #define WM831X_TCH_RPU_WIDTH 4 /* TCH_RPU - [3:0] */ 50 51 /* 52 * R16426-8 (0x402A-C) - Touch Data X/Y/X 53 */ 54 #define WM831X_TCH_PD 0x8000 /* TCH_PD1 */ 55 #define WM831X_TCH_DATA_MASK 0x0FFF /* TCH_DATA - [11:0] */ 56 #define WM831X_TCH_DATA_SHIFT 0 /* TCH_DATA - [11:0] */ 57 #define WM831X_TCH_DATA_WIDTH 12 /* TCH_DATA - [11:0] */ 58 59 struct wm831x_ts { 60 struct input_dev *input_dev; 61 struct wm831x *wm831x; 62 unsigned int data_irq; 63 unsigned int pd_irq; 64 bool pressure; 65 bool pen_down; 66 struct work_struct pd_data_work; 67 }; 68 69 static void wm831x_pd_data_work(struct work_struct *work) 70 { 71 struct wm831x_ts *wm831x_ts = 72 container_of(work, struct wm831x_ts, pd_data_work); 73 74 if (wm831x_ts->pen_down) { 75 enable_irq(wm831x_ts->data_irq); 76 dev_dbg(wm831x_ts->wm831x->dev, "IRQ PD->DATA done\n"); 77 } else { 78 enable_irq(wm831x_ts->pd_irq); 79 dev_dbg(wm831x_ts->wm831x->dev, "IRQ DATA->PD done\n"); 80 } 81 } 82 83 static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data) 84 { 85 struct wm831x_ts *wm831x_ts = irq_data; 86 struct wm831x *wm831x = wm831x_ts->wm831x; 87 static int data_types[] = { ABS_X, ABS_Y, ABS_PRESSURE }; 88 u16 data[3]; 89 int count; 90 int i, ret; 91 92 if (wm831x_ts->pressure) 93 count = 3; 94 else 95 count = 2; 96 97 wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1, 98 WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT); 99 100 ret = wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count, 101 data); 102 if (ret != 0) { 103 dev_err(wm831x->dev, "Failed to read touch data: %d\n", 104 ret); 105 return IRQ_NONE; 106 } 107 108 /* 109 * We get a pen down reading on every reading, report pen up if any 110 * individual reading does so. 111 */ 112 wm831x_ts->pen_down = true; 113 for (i = 0; i < count; i++) { 114 if (!(data[i] & WM831X_TCH_PD)) { 115 wm831x_ts->pen_down = false; 116 continue; 117 } 118 input_report_abs(wm831x_ts->input_dev, data_types[i], 119 data[i] & WM831X_TCH_DATA_MASK); 120 } 121 122 if (!wm831x_ts->pen_down) { 123 /* Switch from data to pen down */ 124 dev_dbg(wm831x->dev, "IRQ DATA->PD\n"); 125 126 disable_irq_nosync(wm831x_ts->data_irq); 127 128 /* Don't need data any more */ 129 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1, 130 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | 131 WM831X_TCH_Z_ENA, 0); 132 133 /* Flush any final samples that arrived while reading */ 134 wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1, 135 WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT); 136 137 wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count, data); 138 139 if (wm831x_ts->pressure) 140 input_report_abs(wm831x_ts->input_dev, 141 ABS_PRESSURE, 0); 142 143 input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 0); 144 145 schedule_work(&wm831x_ts->pd_data_work); 146 } else { 147 input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 1); 148 } 149 150 input_sync(wm831x_ts->input_dev); 151 152 return IRQ_HANDLED; 153 } 154 155 static irqreturn_t wm831x_ts_pen_down_irq(int irq, void *irq_data) 156 { 157 struct wm831x_ts *wm831x_ts = irq_data; 158 struct wm831x *wm831x = wm831x_ts->wm831x; 159 int ena = 0; 160 161 if (wm831x_ts->pen_down) 162 return IRQ_HANDLED; 163 164 disable_irq_nosync(wm831x_ts->pd_irq); 165 166 /* Start collecting data */ 167 if (wm831x_ts->pressure) 168 ena |= WM831X_TCH_Z_ENA; 169 170 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1, 171 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA, 172 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | ena); 173 174 wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1, 175 WM831X_TCHPD_EINT, WM831X_TCHPD_EINT); 176 177 wm831x_ts->pen_down = true; 178 179 /* Switch from pen down to data */ 180 dev_dbg(wm831x->dev, "IRQ PD->DATA\n"); 181 schedule_work(&wm831x_ts->pd_data_work); 182 183 return IRQ_HANDLED; 184 } 185 186 static int wm831x_ts_input_open(struct input_dev *idev) 187 { 188 struct wm831x_ts *wm831x_ts = input_get_drvdata(idev); 189 struct wm831x *wm831x = wm831x_ts->wm831x; 190 191 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1, 192 WM831X_TCH_ENA | WM831X_TCH_CVT_ENA | 193 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | 194 WM831X_TCH_Z_ENA, WM831X_TCH_ENA); 195 196 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1, 197 WM831X_TCH_CVT_ENA, WM831X_TCH_CVT_ENA); 198 199 return 0; 200 } 201 202 static void wm831x_ts_input_close(struct input_dev *idev) 203 { 204 struct wm831x_ts *wm831x_ts = input_get_drvdata(idev); 205 struct wm831x *wm831x = wm831x_ts->wm831x; 206 207 /* Shut the controller down, disabling all other functionality too */ 208 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1, 209 WM831X_TCH_ENA | WM831X_TCH_X_ENA | 210 WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA, 0); 211 212 /* Make sure any pending IRQs are done, the above will prevent 213 * new ones firing. 214 */ 215 synchronize_irq(wm831x_ts->data_irq); 216 synchronize_irq(wm831x_ts->pd_irq); 217 218 /* Make sure the IRQ completion work is quiesced */ 219 flush_work(&wm831x_ts->pd_data_work); 220 221 /* If we ended up with the pen down then make sure we revert back 222 * to pen detection state for the next time we start up. 223 */ 224 if (wm831x_ts->pen_down) { 225 disable_irq(wm831x_ts->data_irq); 226 enable_irq(wm831x_ts->pd_irq); 227 wm831x_ts->pen_down = false; 228 } 229 } 230 231 static int wm831x_ts_probe(struct platform_device *pdev) 232 { 233 struct wm831x_ts *wm831x_ts; 234 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); 235 struct wm831x_pdata *core_pdata = dev_get_platdata(pdev->dev.parent); 236 struct wm831x_touch_pdata *pdata = NULL; 237 struct input_dev *input_dev; 238 int error, irqf; 239 240 if (core_pdata) 241 pdata = core_pdata->touch; 242 243 wm831x_ts = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_ts), 244 GFP_KERNEL); 245 input_dev = devm_input_allocate_device(&pdev->dev); 246 if (!wm831x_ts || !input_dev) { 247 error = -ENOMEM; 248 goto err_alloc; 249 } 250 251 wm831x_ts->wm831x = wm831x; 252 wm831x_ts->input_dev = input_dev; 253 INIT_WORK(&wm831x_ts->pd_data_work, wm831x_pd_data_work); 254 255 /* 256 * If we have a direct IRQ use it, otherwise use the interrupt 257 * from the WM831x IRQ controller. 258 */ 259 wm831x_ts->data_irq = wm831x_irq(wm831x, 260 platform_get_irq_byname(pdev, 261 "TCHDATA")); 262 if (pdata && pdata->data_irq) 263 wm831x_ts->data_irq = pdata->data_irq; 264 265 wm831x_ts->pd_irq = wm831x_irq(wm831x, 266 platform_get_irq_byname(pdev, "TCHPD")); 267 if (pdata && pdata->pd_irq) 268 wm831x_ts->pd_irq = pdata->pd_irq; 269 270 if (pdata) 271 wm831x_ts->pressure = pdata->pressure; 272 else 273 wm831x_ts->pressure = true; 274 275 /* Five wire touchscreens can't report pressure */ 276 if (pdata && pdata->fivewire) { 277 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2, 278 WM831X_TCH_5WIRE, WM831X_TCH_5WIRE); 279 280 /* Pressure measurements are not possible for five wire mode */ 281 WARN_ON(pdata->pressure && pdata->fivewire); 282 wm831x_ts->pressure = false; 283 } else { 284 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2, 285 WM831X_TCH_5WIRE, 0); 286 } 287 288 if (pdata) { 289 switch (pdata->isel) { 290 default: 291 dev_err(&pdev->dev, "Unsupported ISEL setting: %d\n", 292 pdata->isel); 293 fallthrough; 294 case 200: 295 case 0: 296 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2, 297 WM831X_TCH_ISEL, 0); 298 break; 299 case 400: 300 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2, 301 WM831X_TCH_ISEL, WM831X_TCH_ISEL); 302 break; 303 } 304 } 305 306 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2, 307 WM831X_TCH_PDONLY, 0); 308 309 /* Default to 96 samples/sec */ 310 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1, 311 WM831X_TCH_RATE_MASK, 6); 312 313 if (pdata && pdata->data_irqf) 314 irqf = pdata->data_irqf; 315 else 316 irqf = IRQF_TRIGGER_HIGH; 317 318 error = request_threaded_irq(wm831x_ts->data_irq, 319 NULL, wm831x_ts_data_irq, 320 irqf | IRQF_ONESHOT, 321 "Touchscreen data", wm831x_ts); 322 if (error) { 323 dev_err(&pdev->dev, "Failed to request data IRQ %d: %d\n", 324 wm831x_ts->data_irq, error); 325 goto err_alloc; 326 } 327 disable_irq(wm831x_ts->data_irq); 328 329 if (pdata && pdata->pd_irqf) 330 irqf = pdata->pd_irqf; 331 else 332 irqf = IRQF_TRIGGER_HIGH; 333 334 error = request_threaded_irq(wm831x_ts->pd_irq, 335 NULL, wm831x_ts_pen_down_irq, 336 irqf | IRQF_ONESHOT, 337 "Touchscreen pen down", wm831x_ts); 338 if (error) { 339 dev_err(&pdev->dev, "Failed to request pen down IRQ %d: %d\n", 340 wm831x_ts->pd_irq, error); 341 goto err_data_irq; 342 } 343 344 /* set up touch configuration */ 345 input_dev->name = "WM831x touchscreen"; 346 input_dev->phys = "wm831x"; 347 input_dev->open = wm831x_ts_input_open; 348 input_dev->close = wm831x_ts_input_close; 349 350 __set_bit(EV_ABS, input_dev->evbit); 351 __set_bit(EV_KEY, input_dev->evbit); 352 __set_bit(BTN_TOUCH, input_dev->keybit); 353 354 input_set_abs_params(input_dev, ABS_X, 0, 4095, 5, 0); 355 input_set_abs_params(input_dev, ABS_Y, 0, 4095, 5, 0); 356 if (wm831x_ts->pressure) 357 input_set_abs_params(input_dev, ABS_PRESSURE, 0, 4095, 5, 0); 358 359 input_set_drvdata(input_dev, wm831x_ts); 360 input_dev->dev.parent = &pdev->dev; 361 362 error = input_register_device(input_dev); 363 if (error) 364 goto err_pd_irq; 365 366 platform_set_drvdata(pdev, wm831x_ts); 367 return 0; 368 369 err_pd_irq: 370 free_irq(wm831x_ts->pd_irq, wm831x_ts); 371 err_data_irq: 372 free_irq(wm831x_ts->data_irq, wm831x_ts); 373 err_alloc: 374 375 return error; 376 } 377 378 static int wm831x_ts_remove(struct platform_device *pdev) 379 { 380 struct wm831x_ts *wm831x_ts = platform_get_drvdata(pdev); 381 382 free_irq(wm831x_ts->pd_irq, wm831x_ts); 383 free_irq(wm831x_ts->data_irq, wm831x_ts); 384 385 return 0; 386 } 387 388 static struct platform_driver wm831x_ts_driver = { 389 .driver = { 390 .name = "wm831x-touch", 391 }, 392 .probe = wm831x_ts_probe, 393 .remove = wm831x_ts_remove, 394 }; 395 module_platform_driver(wm831x_ts_driver); 396 397 /* Module information */ 398 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 399 MODULE_DESCRIPTION("WM831x PMIC touchscreen driver"); 400 MODULE_LICENSE("GPL"); 401 MODULE_ALIAS("platform:wm831x-touch"); 402