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_sync(ts->idev); 124 } 125 126 static irqreturn_t stmpe_ts_handler(int irq, void *data) 127 { 128 u8 data_set[4]; 129 int x, y, z; 130 struct stmpe_touch *ts = data; 131 132 /* 133 * Cancel scheduled polling for release if we have new value 134 * available. Wait if the polling is already running. 135 */ 136 cancel_delayed_work_sync(&ts->work); 137 138 /* 139 * The FIFO sometimes just crashes and stops generating interrupts. This 140 * appears to be a silicon bug. We still have to clearify this with 141 * the manufacture. As a workaround we disable the TSC while we are 142 * collecting data and flush the FIFO after reading 143 */ 144 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 145 STMPE_TSC_CTRL_TSC_EN, 0); 146 147 stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set); 148 149 x = (data_set[0] << 4) | (data_set[1] >> 4); 150 y = ((data_set[1] & 0xf) << 8) | data_set[2]; 151 z = data_set[3]; 152 153 input_report_abs(ts->idev, ABS_X, x); 154 input_report_abs(ts->idev, ABS_Y, y); 155 input_report_abs(ts->idev, ABS_PRESSURE, z); 156 input_sync(ts->idev); 157 158 /* flush the FIFO after we have read out our values. */ 159 __stmpe_reset_fifo(ts->stmpe); 160 161 /* reenable the tsc */ 162 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 163 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); 164 165 /* start polling for touch_det to detect release */ 166 schedule_delayed_work(&ts->work, HZ / 50); 167 168 return IRQ_HANDLED; 169 } 170 171 static int stmpe_init_hw(struct stmpe_touch *ts) 172 { 173 int ret; 174 u8 adc_ctrl1, adc_ctrl1_mask, tsc_cfg, tsc_cfg_mask; 175 struct stmpe *stmpe = ts->stmpe; 176 struct device *dev = ts->dev; 177 178 ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC); 179 if (ret) { 180 dev_err(dev, "Could not enable clock for ADC and TS\n"); 181 return ret; 182 } 183 184 adc_ctrl1 = SAMPLE_TIME(ts->sample_time) | MOD_12B(ts->mod_12b) | 185 REF_SEL(ts->ref_sel); 186 adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff); 187 188 ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1, 189 adc_ctrl1_mask, adc_ctrl1); 190 if (ret) { 191 dev_err(dev, "Could not setup ADC\n"); 192 return ret; 193 } 194 195 ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2, 196 ADC_FREQ(0xff), ADC_FREQ(ts->adc_freq)); 197 if (ret) { 198 dev_err(dev, "Could not setup ADC\n"); 199 return ret; 200 } 201 202 tsc_cfg = AVE_CTRL(ts->ave_ctrl) | DET_DELAY(ts->touch_det_delay) | 203 SETTLING(ts->settling); 204 tsc_cfg_mask = AVE_CTRL(0xff) | DET_DELAY(0xff) | SETTLING(0xff); 205 206 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg); 207 if (ret) { 208 dev_err(dev, "Could not config touch\n"); 209 return ret; 210 } 211 212 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z, 213 FRACTION_Z(0xff), FRACTION_Z(ts->fraction_z)); 214 if (ret) { 215 dev_err(dev, "Could not config touch\n"); 216 return ret; 217 } 218 219 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE, 220 I_DRIVE(0xff), I_DRIVE(ts->i_drive)); 221 if (ret) { 222 dev_err(dev, "Could not config touch\n"); 223 return ret; 224 } 225 226 /* set FIFO to 1 for single point reading */ 227 ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1); 228 if (ret) { 229 dev_err(dev, "Could not set FIFO\n"); 230 return ret; 231 } 232 233 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL, 234 OP_MODE(0xff), OP_MODE(OP_MOD_XYZ)); 235 if (ret) { 236 dev_err(dev, "Could not set mode\n"); 237 return ret; 238 } 239 240 return 0; 241 } 242 243 static int stmpe_ts_open(struct input_dev *dev) 244 { 245 struct stmpe_touch *ts = input_get_drvdata(dev); 246 int ret = 0; 247 248 ret = __stmpe_reset_fifo(ts->stmpe); 249 if (ret) 250 return ret; 251 252 return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 253 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); 254 } 255 256 static void stmpe_ts_close(struct input_dev *dev) 257 { 258 struct stmpe_touch *ts = input_get_drvdata(dev); 259 260 cancel_delayed_work_sync(&ts->work); 261 262 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 263 STMPE_TSC_CTRL_TSC_EN, 0); 264 } 265 266 static void stmpe_ts_get_platform_info(struct platform_device *pdev, 267 struct stmpe_touch *ts) 268 { 269 struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent); 270 struct device_node *np = pdev->dev.of_node; 271 struct stmpe_ts_platform_data *ts_pdata = NULL; 272 273 ts->stmpe = stmpe; 274 275 if (stmpe->pdata && stmpe->pdata->ts) { 276 ts_pdata = stmpe->pdata->ts; 277 278 ts->sample_time = ts_pdata->sample_time; 279 ts->mod_12b = ts_pdata->mod_12b; 280 ts->ref_sel = ts_pdata->ref_sel; 281 ts->adc_freq = ts_pdata->adc_freq; 282 ts->ave_ctrl = ts_pdata->ave_ctrl; 283 ts->touch_det_delay = ts_pdata->touch_det_delay; 284 ts->settling = ts_pdata->settling; 285 ts->fraction_z = ts_pdata->fraction_z; 286 ts->i_drive = ts_pdata->i_drive; 287 } else if (np) { 288 u32 val; 289 290 if (!of_property_read_u32(np, "st,sample-time", &val)) 291 ts->sample_time = val; 292 if (!of_property_read_u32(np, "st,mod-12b", &val)) 293 ts->mod_12b = val; 294 if (!of_property_read_u32(np, "st,ref-sel", &val)) 295 ts->ref_sel = val; 296 if (!of_property_read_u32(np, "st,adc-freq", &val)) 297 ts->adc_freq = val; 298 if (!of_property_read_u32(np, "st,ave-ctrl", &val)) 299 ts->ave_ctrl = val; 300 if (!of_property_read_u32(np, "st,touch-det-delay", &val)) 301 ts->touch_det_delay = val; 302 if (!of_property_read_u32(np, "st,settling", &val)) 303 ts->settling = val; 304 if (!of_property_read_u32(np, "st,fraction-z", &val)) 305 ts->fraction_z = val; 306 if (!of_property_read_u32(np, "st,i-drive", &val)) 307 ts->i_drive = val; 308 } 309 } 310 311 static int stmpe_input_probe(struct platform_device *pdev) 312 { 313 struct stmpe_touch *ts; 314 struct input_dev *idev; 315 int error; 316 int ts_irq; 317 318 ts_irq = platform_get_irq_byname(pdev, "FIFO_TH"); 319 if (ts_irq < 0) 320 return ts_irq; 321 322 ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL); 323 if (!ts) 324 return -ENOMEM; 325 326 idev = devm_input_allocate_device(&pdev->dev); 327 if (!idev) 328 return -ENOMEM; 329 330 platform_set_drvdata(pdev, ts); 331 ts->idev = idev; 332 ts->dev = &pdev->dev; 333 334 stmpe_ts_get_platform_info(pdev, ts); 335 336 INIT_DELAYED_WORK(&ts->work, stmpe_work); 337 338 error = devm_request_threaded_irq(&pdev->dev, ts_irq, 339 NULL, stmpe_ts_handler, 340 IRQF_ONESHOT, STMPE_TS_NAME, ts); 341 if (error) { 342 dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq); 343 return error; 344 } 345 346 error = stmpe_init_hw(ts); 347 if (error) 348 return error; 349 350 idev->name = STMPE_TS_NAME; 351 idev->phys = STMPE_TS_NAME"/input0"; 352 idev->id.bustype = BUS_I2C; 353 idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 354 idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 355 356 idev->open = stmpe_ts_open; 357 idev->close = stmpe_ts_close; 358 359 input_set_drvdata(idev, ts); 360 361 input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0); 362 input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0); 363 input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0); 364 365 error = input_register_device(idev); 366 if (error) { 367 dev_err(&pdev->dev, "Could not register input device\n"); 368 return error; 369 } 370 371 return 0; 372 } 373 374 static int stmpe_ts_remove(struct platform_device *pdev) 375 { 376 struct stmpe_touch *ts = platform_get_drvdata(pdev); 377 378 stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN); 379 380 return 0; 381 } 382 383 static struct platform_driver stmpe_ts_driver = { 384 .driver = { 385 .name = STMPE_TS_NAME, 386 .owner = THIS_MODULE, 387 }, 388 .probe = stmpe_input_probe, 389 .remove = stmpe_ts_remove, 390 }; 391 module_platform_driver(stmpe_ts_driver); 392 393 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); 394 MODULE_DESCRIPTION("STMPEXXX touchscreen driver"); 395 MODULE_LICENSE("GPL"); 396 MODULE_ALIAS("platform:" STMPE_TS_NAME); 397