1 /* 2 * STMicroelectronics STMPE811 Touchscreen Driver 3 * 4 * (C) 2010 Luotao Fu <l.fu@pengutronix.de> 5 * All rights reserved. 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License as published by the 9 * Free Software Foundation; either version 2 of the License, or (at your 10 * option) any later version. 11 * 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/sched.h> 17 #include <linux/interrupt.h> 18 #include <linux/init.h> 19 #include <linux/device.h> 20 #include <linux/of.h> 21 #include <linux/platform_device.h> 22 #include <linux/input.h> 23 #include <linux/slab.h> 24 #include <linux/delay.h> 25 #include <linux/i2c.h> 26 #include <linux/workqueue.h> 27 28 #include <linux/mfd/stmpe.h> 29 30 /* Register layouts and functionalities are identical on all stmpexxx variants 31 * with touchscreen controller 32 */ 33 #define STMPE_REG_INT_STA 0x0B 34 #define STMPE_REG_ADC_CTRL1 0x20 35 #define STMPE_REG_ADC_CTRL2 0x21 36 #define STMPE_REG_TSC_CTRL 0x40 37 #define STMPE_REG_TSC_CFG 0x41 38 #define STMPE_REG_FIFO_TH 0x4A 39 #define STMPE_REG_FIFO_STA 0x4B 40 #define STMPE_REG_FIFO_SIZE 0x4C 41 #define STMPE_REG_TSC_DATA_XYZ 0x52 42 #define STMPE_REG_TSC_FRACTION_Z 0x56 43 #define STMPE_REG_TSC_I_DRIVE 0x58 44 45 #define OP_MOD_XYZ 0 46 47 #define STMPE_TSC_CTRL_TSC_EN (1<<0) 48 49 #define STMPE_FIFO_STA_RESET (1<<0) 50 51 #define STMPE_IRQ_TOUCH_DET 0 52 53 #define SAMPLE_TIME(x) ((x & 0xf) << 4) 54 #define MOD_12B(x) ((x & 0x1) << 3) 55 #define REF_SEL(x) ((x & 0x1) << 1) 56 #define ADC_FREQ(x) (x & 0x3) 57 #define AVE_CTRL(x) ((x & 0x3) << 6) 58 #define DET_DELAY(x) ((x & 0x7) << 3) 59 #define SETTLING(x) (x & 0x7) 60 #define FRACTION_Z(x) (x & 0x7) 61 #define I_DRIVE(x) (x & 0x1) 62 #define OP_MODE(x) ((x & 0x7) << 1) 63 64 #define STMPE_TS_NAME "stmpe-ts" 65 #define XY_MASK 0xfff 66 67 struct stmpe_touch { 68 struct stmpe *stmpe; 69 struct input_dev *idev; 70 struct delayed_work work; 71 struct device *dev; 72 u8 sample_time; 73 u8 mod_12b; 74 u8 ref_sel; 75 u8 adc_freq; 76 u8 ave_ctrl; 77 u8 touch_det_delay; 78 u8 settling; 79 u8 fraction_z; 80 u8 i_drive; 81 }; 82 83 static int __stmpe_reset_fifo(struct stmpe *stmpe) 84 { 85 int ret; 86 87 ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, 88 STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET); 89 if (ret) 90 return ret; 91 92 return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, 93 STMPE_FIFO_STA_RESET, 0); 94 } 95 96 static void stmpe_work(struct work_struct *work) 97 { 98 int int_sta; 99 u32 timeout = 40; 100 101 struct stmpe_touch *ts = 102 container_of(work, struct stmpe_touch, work.work); 103 104 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); 105 106 /* 107 * touch_det sometimes get desasserted or just get stuck. This appears 108 * to be a silicon bug, We still have to clearify this with the 109 * manufacture. As a workaround We release the key anyway if the 110 * touch_det keeps coming in after 4ms, while the FIFO contains no value 111 * during the whole time. 112 */ 113 while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) { 114 timeout--; 115 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); 116 udelay(100); 117 } 118 119 /* reset the FIFO before we report release event */ 120 __stmpe_reset_fifo(ts->stmpe); 121 122 input_report_abs(ts->idev, ABS_PRESSURE, 0); 123 input_report_key(ts->idev, BTN_TOUCH, 0); 124 input_sync(ts->idev); 125 } 126 127 static irqreturn_t stmpe_ts_handler(int irq, void *data) 128 { 129 u8 data_set[4]; 130 int x, y, z; 131 struct stmpe_touch *ts = data; 132 133 /* 134 * Cancel scheduled polling for release if we have new value 135 * available. Wait if the polling is already running. 136 */ 137 cancel_delayed_work_sync(&ts->work); 138 139 /* 140 * The FIFO sometimes just crashes and stops generating interrupts. This 141 * appears to be a silicon bug. We still have to clearify this with 142 * the manufacture. As a workaround we disable the TSC while we are 143 * collecting data and flush the FIFO after reading 144 */ 145 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 146 STMPE_TSC_CTRL_TSC_EN, 0); 147 148 stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set); 149 150 x = (data_set[0] << 4) | (data_set[1] >> 4); 151 y = ((data_set[1] & 0xf) << 8) | data_set[2]; 152 z = data_set[3]; 153 154 input_report_abs(ts->idev, ABS_X, x); 155 input_report_abs(ts->idev, ABS_Y, y); 156 input_report_abs(ts->idev, ABS_PRESSURE, z); 157 input_report_key(ts->idev, BTN_TOUCH, 1); 158 input_sync(ts->idev); 159 160 /* flush the FIFO after we have read out our values. */ 161 __stmpe_reset_fifo(ts->stmpe); 162 163 /* reenable the tsc */ 164 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 165 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); 166 167 /* start polling for touch_det to detect release */ 168 schedule_delayed_work(&ts->work, HZ / 50); 169 170 return IRQ_HANDLED; 171 } 172 173 static int stmpe_init_hw(struct stmpe_touch *ts) 174 { 175 int ret; 176 u8 adc_ctrl1, adc_ctrl1_mask, tsc_cfg, tsc_cfg_mask; 177 struct stmpe *stmpe = ts->stmpe; 178 struct device *dev = ts->dev; 179 180 ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC); 181 if (ret) { 182 dev_err(dev, "Could not enable clock for ADC and TS\n"); 183 return ret; 184 } 185 186 adc_ctrl1 = SAMPLE_TIME(ts->sample_time) | MOD_12B(ts->mod_12b) | 187 REF_SEL(ts->ref_sel); 188 adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff); 189 190 ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1, 191 adc_ctrl1_mask, adc_ctrl1); 192 if (ret) { 193 dev_err(dev, "Could not setup ADC\n"); 194 return ret; 195 } 196 197 ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2, 198 ADC_FREQ(0xff), ADC_FREQ(ts->adc_freq)); 199 if (ret) { 200 dev_err(dev, "Could not setup ADC\n"); 201 return ret; 202 } 203 204 tsc_cfg = AVE_CTRL(ts->ave_ctrl) | DET_DELAY(ts->touch_det_delay) | 205 SETTLING(ts->settling); 206 tsc_cfg_mask = AVE_CTRL(0xff) | DET_DELAY(0xff) | SETTLING(0xff); 207 208 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg); 209 if (ret) { 210 dev_err(dev, "Could not config touch\n"); 211 return ret; 212 } 213 214 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z, 215 FRACTION_Z(0xff), FRACTION_Z(ts->fraction_z)); 216 if (ret) { 217 dev_err(dev, "Could not config touch\n"); 218 return ret; 219 } 220 221 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE, 222 I_DRIVE(0xff), I_DRIVE(ts->i_drive)); 223 if (ret) { 224 dev_err(dev, "Could not config touch\n"); 225 return ret; 226 } 227 228 /* set FIFO to 1 for single point reading */ 229 ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1); 230 if (ret) { 231 dev_err(dev, "Could not set FIFO\n"); 232 return ret; 233 } 234 235 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL, 236 OP_MODE(0xff), OP_MODE(OP_MOD_XYZ)); 237 if (ret) { 238 dev_err(dev, "Could not set mode\n"); 239 return ret; 240 } 241 242 return 0; 243 } 244 245 static int stmpe_ts_open(struct input_dev *dev) 246 { 247 struct stmpe_touch *ts = input_get_drvdata(dev); 248 int ret = 0; 249 250 ret = __stmpe_reset_fifo(ts->stmpe); 251 if (ret) 252 return ret; 253 254 return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 255 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); 256 } 257 258 static void stmpe_ts_close(struct input_dev *dev) 259 { 260 struct stmpe_touch *ts = input_get_drvdata(dev); 261 262 cancel_delayed_work_sync(&ts->work); 263 264 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 265 STMPE_TSC_CTRL_TSC_EN, 0); 266 } 267 268 static void stmpe_ts_get_platform_info(struct platform_device *pdev, 269 struct stmpe_touch *ts) 270 { 271 struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent); 272 struct device_node *np = pdev->dev.of_node; 273 struct stmpe_ts_platform_data *ts_pdata = NULL; 274 275 ts->stmpe = stmpe; 276 277 if (stmpe->pdata && stmpe->pdata->ts) { 278 ts_pdata = stmpe->pdata->ts; 279 280 ts->sample_time = ts_pdata->sample_time; 281 ts->mod_12b = ts_pdata->mod_12b; 282 ts->ref_sel = ts_pdata->ref_sel; 283 ts->adc_freq = ts_pdata->adc_freq; 284 ts->ave_ctrl = ts_pdata->ave_ctrl; 285 ts->touch_det_delay = ts_pdata->touch_det_delay; 286 ts->settling = ts_pdata->settling; 287 ts->fraction_z = ts_pdata->fraction_z; 288 ts->i_drive = ts_pdata->i_drive; 289 } else if (np) { 290 u32 val; 291 292 if (!of_property_read_u32(np, "st,sample-time", &val)) 293 ts->sample_time = val; 294 if (!of_property_read_u32(np, "st,mod-12b", &val)) 295 ts->mod_12b = val; 296 if (!of_property_read_u32(np, "st,ref-sel", &val)) 297 ts->ref_sel = val; 298 if (!of_property_read_u32(np, "st,adc-freq", &val)) 299 ts->adc_freq = val; 300 if (!of_property_read_u32(np, "st,ave-ctrl", &val)) 301 ts->ave_ctrl = val; 302 if (!of_property_read_u32(np, "st,touch-det-delay", &val)) 303 ts->touch_det_delay = val; 304 if (!of_property_read_u32(np, "st,settling", &val)) 305 ts->settling = val; 306 if (!of_property_read_u32(np, "st,fraction-z", &val)) 307 ts->fraction_z = val; 308 if (!of_property_read_u32(np, "st,i-drive", &val)) 309 ts->i_drive = val; 310 } 311 } 312 313 static int stmpe_input_probe(struct platform_device *pdev) 314 { 315 struct stmpe_touch *ts; 316 struct input_dev *idev; 317 int error; 318 int ts_irq; 319 320 ts_irq = platform_get_irq_byname(pdev, "FIFO_TH"); 321 if (ts_irq < 0) 322 return ts_irq; 323 324 ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL); 325 if (!ts) 326 return -ENOMEM; 327 328 idev = devm_input_allocate_device(&pdev->dev); 329 if (!idev) 330 return -ENOMEM; 331 332 platform_set_drvdata(pdev, ts); 333 ts->idev = idev; 334 ts->dev = &pdev->dev; 335 336 stmpe_ts_get_platform_info(pdev, ts); 337 338 INIT_DELAYED_WORK(&ts->work, stmpe_work); 339 340 error = devm_request_threaded_irq(&pdev->dev, ts_irq, 341 NULL, stmpe_ts_handler, 342 IRQF_ONESHOT, STMPE_TS_NAME, ts); 343 if (error) { 344 dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq); 345 return error; 346 } 347 348 error = stmpe_init_hw(ts); 349 if (error) 350 return error; 351 352 idev->name = STMPE_TS_NAME; 353 idev->phys = STMPE_TS_NAME"/input0"; 354 idev->id.bustype = BUS_I2C; 355 idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 356 idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 357 358 idev->open = stmpe_ts_open; 359 idev->close = stmpe_ts_close; 360 361 input_set_drvdata(idev, ts); 362 363 input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0); 364 input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0); 365 input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0); 366 367 error = input_register_device(idev); 368 if (error) { 369 dev_err(&pdev->dev, "Could not register input device\n"); 370 return error; 371 } 372 373 return 0; 374 } 375 376 static int stmpe_ts_remove(struct platform_device *pdev) 377 { 378 struct stmpe_touch *ts = platform_get_drvdata(pdev); 379 380 stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN); 381 382 return 0; 383 } 384 385 static struct platform_driver stmpe_ts_driver = { 386 .driver = { 387 .name = STMPE_TS_NAME, 388 .owner = THIS_MODULE, 389 }, 390 .probe = stmpe_input_probe, 391 .remove = stmpe_ts_remove, 392 }; 393 module_platform_driver(stmpe_ts_driver); 394 395 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); 396 MODULE_DESCRIPTION("STMPEXXX touchscreen driver"); 397 MODULE_LICENSE("GPL"); 398 MODULE_ALIAS("platform:" STMPE_TS_NAME); 399