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/device.h> 19 #include <linux/of.h> 20 #include <linux/platform_device.h> 21 #include <linux/input.h> 22 #include <linux/slab.h> 23 #include <linux/delay.h> 24 #include <linux/i2c.h> 25 #include <linux/workqueue.h> 26 27 #include <linux/mfd/stmpe.h> 28 29 /* Register layouts and functionalities are identical on all stmpexxx variants 30 * with touchscreen controller 31 */ 32 #define STMPE_REG_INT_STA 0x0B 33 #define STMPE_REG_ADC_CTRL1 0x20 34 #define STMPE_REG_ADC_CTRL2 0x21 35 #define STMPE_REG_TSC_CTRL 0x40 36 #define STMPE_REG_TSC_CFG 0x41 37 #define STMPE_REG_FIFO_TH 0x4A 38 #define STMPE_REG_FIFO_STA 0x4B 39 #define STMPE_REG_FIFO_SIZE 0x4C 40 #define STMPE_REG_TSC_DATA_XYZ 0x52 41 #define STMPE_REG_TSC_FRACTION_Z 0x56 42 #define STMPE_REG_TSC_I_DRIVE 0x58 43 44 #define OP_MOD_XYZ 0 45 46 #define STMPE_TSC_CTRL_TSC_EN (1<<0) 47 48 #define STMPE_FIFO_STA_RESET (1<<0) 49 50 #define STMPE_IRQ_TOUCH_DET 0 51 52 #define SAMPLE_TIME(x) ((x & 0xf) << 4) 53 #define MOD_12B(x) ((x & 0x1) << 3) 54 #define REF_SEL(x) ((x & 0x1) << 1) 55 #define ADC_FREQ(x) (x & 0x3) 56 #define AVE_CTRL(x) ((x & 0x3) << 6) 57 #define DET_DELAY(x) ((x & 0x7) << 3) 58 #define SETTLING(x) (x & 0x7) 59 #define FRACTION_Z(x) (x & 0x7) 60 #define I_DRIVE(x) (x & 0x1) 61 #define OP_MODE(x) ((x & 0x7) << 1) 62 63 #define STMPE_TS_NAME "stmpe-ts" 64 #define XY_MASK 0xfff 65 66 /** 67 * struct stmpe_touch - stmpe811 touch screen controller state 68 * @stmpe: pointer back to STMPE MFD container 69 * @idev: registered input device 70 * @work: a work item used to scan the device 71 * @dev: a pointer back to the MFD cell struct device* 72 * @sample_time: ADC converstion time in number of clock. 73 * (0 -> 36 clocks, 1 -> 44 clocks, 2 -> 56 clocks, 3 -> 64 clocks, 74 * 4 -> 80 clocks, 5 -> 96 clocks, 6 -> 144 clocks), 75 * recommended is 4. 76 * @mod_12b: ADC Bit mode (0 -> 10bit ADC, 1 -> 12bit ADC) 77 * @ref_sel: ADC reference source 78 * (0 -> internal reference, 1 -> external reference) 79 * @adc_freq: ADC Clock speed 80 * (0 -> 1.625 MHz, 1 -> 3.25 MHz, 2 || 3 -> 6.5 MHz) 81 * @ave_ctrl: Sample average control 82 * (0 -> 1 sample, 1 -> 2 samples, 2 -> 4 samples, 3 -> 8 samples) 83 * @touch_det_delay: Touch detect interrupt delay 84 * (0 -> 10 us, 1 -> 50 us, 2 -> 100 us, 3 -> 500 us, 85 * 4-> 1 ms, 5 -> 5 ms, 6 -> 10 ms, 7 -> 50 ms) 86 * recommended is 3 87 * @settling: Panel driver settling time 88 * (0 -> 10 us, 1 -> 100 us, 2 -> 500 us, 3 -> 1 ms, 89 * 4 -> 5 ms, 5 -> 10 ms, 6 for 50 ms, 7 -> 100 ms) 90 * recommended is 2 91 * @fraction_z: Length of the fractional part in z 92 * (fraction_z ([0..7]) = Count of the fractional part) 93 * recommended is 7 94 * @i_drive: current limit value of the touchscreen drivers 95 * (0 -> 20 mA typical 35 mA max, 1 -> 50 mA typical 80 mA max) 96 */ 97 struct stmpe_touch { 98 struct stmpe *stmpe; 99 struct input_dev *idev; 100 struct delayed_work work; 101 struct device *dev; 102 u8 sample_time; 103 u8 mod_12b; 104 u8 ref_sel; 105 u8 adc_freq; 106 u8 ave_ctrl; 107 u8 touch_det_delay; 108 u8 settling; 109 u8 fraction_z; 110 u8 i_drive; 111 }; 112 113 static int __stmpe_reset_fifo(struct stmpe *stmpe) 114 { 115 int ret; 116 117 ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, 118 STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET); 119 if (ret) 120 return ret; 121 122 return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, 123 STMPE_FIFO_STA_RESET, 0); 124 } 125 126 static void stmpe_work(struct work_struct *work) 127 { 128 int int_sta; 129 u32 timeout = 40; 130 131 struct stmpe_touch *ts = 132 container_of(work, struct stmpe_touch, work.work); 133 134 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); 135 136 /* 137 * touch_det sometimes get desasserted or just get stuck. This appears 138 * to be a silicon bug, We still have to clearify this with the 139 * manufacture. As a workaround We release the key anyway if the 140 * touch_det keeps coming in after 4ms, while the FIFO contains no value 141 * during the whole time. 142 */ 143 while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) { 144 timeout--; 145 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); 146 udelay(100); 147 } 148 149 /* reset the FIFO before we report release event */ 150 __stmpe_reset_fifo(ts->stmpe); 151 152 input_report_abs(ts->idev, ABS_PRESSURE, 0); 153 input_report_key(ts->idev, BTN_TOUCH, 0); 154 input_sync(ts->idev); 155 } 156 157 static irqreturn_t stmpe_ts_handler(int irq, void *data) 158 { 159 u8 data_set[4]; 160 int x, y, z; 161 struct stmpe_touch *ts = data; 162 163 /* 164 * Cancel scheduled polling for release if we have new value 165 * available. Wait if the polling is already running. 166 */ 167 cancel_delayed_work_sync(&ts->work); 168 169 /* 170 * The FIFO sometimes just crashes and stops generating interrupts. This 171 * appears to be a silicon bug. We still have to clearify this with 172 * the manufacture. As a workaround we disable the TSC while we are 173 * collecting data and flush the FIFO after reading 174 */ 175 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 176 STMPE_TSC_CTRL_TSC_EN, 0); 177 178 stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set); 179 180 x = (data_set[0] << 4) | (data_set[1] >> 4); 181 y = ((data_set[1] & 0xf) << 8) | data_set[2]; 182 z = data_set[3]; 183 184 input_report_abs(ts->idev, ABS_X, x); 185 input_report_abs(ts->idev, ABS_Y, y); 186 input_report_abs(ts->idev, ABS_PRESSURE, z); 187 input_report_key(ts->idev, BTN_TOUCH, 1); 188 input_sync(ts->idev); 189 190 /* flush the FIFO after we have read out our values. */ 191 __stmpe_reset_fifo(ts->stmpe); 192 193 /* reenable the tsc */ 194 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 195 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); 196 197 /* start polling for touch_det to detect release */ 198 schedule_delayed_work(&ts->work, msecs_to_jiffies(50)); 199 200 return IRQ_HANDLED; 201 } 202 203 static int stmpe_init_hw(struct stmpe_touch *ts) 204 { 205 int ret; 206 u8 adc_ctrl1, adc_ctrl1_mask, tsc_cfg, tsc_cfg_mask; 207 struct stmpe *stmpe = ts->stmpe; 208 struct device *dev = ts->dev; 209 210 ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC); 211 if (ret) { 212 dev_err(dev, "Could not enable clock for ADC and TS\n"); 213 return ret; 214 } 215 216 adc_ctrl1 = SAMPLE_TIME(ts->sample_time) | MOD_12B(ts->mod_12b) | 217 REF_SEL(ts->ref_sel); 218 adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff); 219 220 ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1, 221 adc_ctrl1_mask, adc_ctrl1); 222 if (ret) { 223 dev_err(dev, "Could not setup ADC\n"); 224 return ret; 225 } 226 227 ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2, 228 ADC_FREQ(0xff), ADC_FREQ(ts->adc_freq)); 229 if (ret) { 230 dev_err(dev, "Could not setup ADC\n"); 231 return ret; 232 } 233 234 tsc_cfg = AVE_CTRL(ts->ave_ctrl) | DET_DELAY(ts->touch_det_delay) | 235 SETTLING(ts->settling); 236 tsc_cfg_mask = AVE_CTRL(0xff) | DET_DELAY(0xff) | SETTLING(0xff); 237 238 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg); 239 if (ret) { 240 dev_err(dev, "Could not config touch\n"); 241 return ret; 242 } 243 244 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z, 245 FRACTION_Z(0xff), FRACTION_Z(ts->fraction_z)); 246 if (ret) { 247 dev_err(dev, "Could not config touch\n"); 248 return ret; 249 } 250 251 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE, 252 I_DRIVE(0xff), I_DRIVE(ts->i_drive)); 253 if (ret) { 254 dev_err(dev, "Could not config touch\n"); 255 return ret; 256 } 257 258 /* set FIFO to 1 for single point reading */ 259 ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1); 260 if (ret) { 261 dev_err(dev, "Could not set FIFO\n"); 262 return ret; 263 } 264 265 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL, 266 OP_MODE(0xff), OP_MODE(OP_MOD_XYZ)); 267 if (ret) { 268 dev_err(dev, "Could not set mode\n"); 269 return ret; 270 } 271 272 return 0; 273 } 274 275 static int stmpe_ts_open(struct input_dev *dev) 276 { 277 struct stmpe_touch *ts = input_get_drvdata(dev); 278 int ret = 0; 279 280 ret = __stmpe_reset_fifo(ts->stmpe); 281 if (ret) 282 return ret; 283 284 return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 285 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); 286 } 287 288 static void stmpe_ts_close(struct input_dev *dev) 289 { 290 struct stmpe_touch *ts = input_get_drvdata(dev); 291 292 cancel_delayed_work_sync(&ts->work); 293 294 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 295 STMPE_TSC_CTRL_TSC_EN, 0); 296 } 297 298 static void stmpe_ts_get_platform_info(struct platform_device *pdev, 299 struct stmpe_touch *ts) 300 { 301 struct device_node *np = pdev->dev.of_node; 302 u32 val; 303 304 if (np) { 305 if (!of_property_read_u32(np, "st,sample-time", &val)) 306 ts->sample_time = val; 307 if (!of_property_read_u32(np, "st,mod-12b", &val)) 308 ts->mod_12b = val; 309 if (!of_property_read_u32(np, "st,ref-sel", &val)) 310 ts->ref_sel = val; 311 if (!of_property_read_u32(np, "st,adc-freq", &val)) 312 ts->adc_freq = val; 313 if (!of_property_read_u32(np, "st,ave-ctrl", &val)) 314 ts->ave_ctrl = val; 315 if (!of_property_read_u32(np, "st,touch-det-delay", &val)) 316 ts->touch_det_delay = val; 317 if (!of_property_read_u32(np, "st,settling", &val)) 318 ts->settling = val; 319 if (!of_property_read_u32(np, "st,fraction-z", &val)) 320 ts->fraction_z = val; 321 if (!of_property_read_u32(np, "st,i-drive", &val)) 322 ts->i_drive = val; 323 } 324 } 325 326 static int stmpe_input_probe(struct platform_device *pdev) 327 { 328 struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent); 329 struct stmpe_touch *ts; 330 struct input_dev *idev; 331 int error; 332 int ts_irq; 333 334 ts_irq = platform_get_irq_byname(pdev, "FIFO_TH"); 335 if (ts_irq < 0) 336 return ts_irq; 337 338 ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL); 339 if (!ts) 340 return -ENOMEM; 341 342 idev = devm_input_allocate_device(&pdev->dev); 343 if (!idev) 344 return -ENOMEM; 345 346 platform_set_drvdata(pdev, ts); 347 ts->stmpe = stmpe; 348 ts->idev = idev; 349 ts->dev = &pdev->dev; 350 351 stmpe_ts_get_platform_info(pdev, ts); 352 353 INIT_DELAYED_WORK(&ts->work, stmpe_work); 354 355 error = devm_request_threaded_irq(&pdev->dev, ts_irq, 356 NULL, stmpe_ts_handler, 357 IRQF_ONESHOT, STMPE_TS_NAME, ts); 358 if (error) { 359 dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq); 360 return error; 361 } 362 363 error = stmpe_init_hw(ts); 364 if (error) 365 return error; 366 367 idev->name = STMPE_TS_NAME; 368 idev->phys = STMPE_TS_NAME"/input0"; 369 idev->id.bustype = BUS_I2C; 370 371 idev->open = stmpe_ts_open; 372 idev->close = stmpe_ts_close; 373 374 input_set_drvdata(idev, ts); 375 376 input_set_capability(idev, EV_KEY, BTN_TOUCH); 377 input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0); 378 input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0); 379 input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0); 380 381 error = input_register_device(idev); 382 if (error) { 383 dev_err(&pdev->dev, "Could not register input device\n"); 384 return error; 385 } 386 387 return 0; 388 } 389 390 static int stmpe_ts_remove(struct platform_device *pdev) 391 { 392 struct stmpe_touch *ts = platform_get_drvdata(pdev); 393 394 stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN); 395 396 return 0; 397 } 398 399 static struct platform_driver stmpe_ts_driver = { 400 .driver = { 401 .name = STMPE_TS_NAME, 402 }, 403 .probe = stmpe_input_probe, 404 .remove = stmpe_ts_remove, 405 }; 406 module_platform_driver(stmpe_ts_driver); 407 408 static const struct of_device_id stmpe_ts_ids[] = { 409 { .compatible = "st,stmpe-ts", }, 410 { }, 411 }; 412 MODULE_DEVICE_TABLE(of, stmpe_ts_ids); 413 414 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); 415 MODULE_DESCRIPTION("STMPEXXX touchscreen driver"); 416 MODULE_LICENSE("GPL"); 417