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 struct stmpe_touch { 67 struct stmpe *stmpe; 68 struct input_dev *idev; 69 struct delayed_work work; 70 struct device *dev; 71 u8 sample_time; 72 u8 mod_12b; 73 u8 ref_sel; 74 u8 adc_freq; 75 u8 ave_ctrl; 76 u8 touch_det_delay; 77 u8 settling; 78 u8 fraction_z; 79 u8 i_drive; 80 }; 81 82 static int __stmpe_reset_fifo(struct stmpe *stmpe) 83 { 84 int ret; 85 86 ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, 87 STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET); 88 if (ret) 89 return ret; 90 91 return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, 92 STMPE_FIFO_STA_RESET, 0); 93 } 94 95 static void stmpe_work(struct work_struct *work) 96 { 97 int int_sta; 98 u32 timeout = 40; 99 100 struct stmpe_touch *ts = 101 container_of(work, struct stmpe_touch, work.work); 102 103 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); 104 105 /* 106 * touch_det sometimes get desasserted or just get stuck. This appears 107 * to be a silicon bug, We still have to clearify this with the 108 * manufacture. As a workaround We release the key anyway if the 109 * touch_det keeps coming in after 4ms, while the FIFO contains no value 110 * during the whole time. 111 */ 112 while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) { 113 timeout--; 114 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); 115 udelay(100); 116 } 117 118 /* reset the FIFO before we report release event */ 119 __stmpe_reset_fifo(ts->stmpe); 120 121 input_report_abs(ts->idev, ABS_PRESSURE, 0); 122 input_report_key(ts->idev, BTN_TOUCH, 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_report_key(ts->idev, BTN_TOUCH, 1); 157 input_sync(ts->idev); 158 159 /* flush the FIFO after we have read out our values. */ 160 __stmpe_reset_fifo(ts->stmpe); 161 162 /* reenable the tsc */ 163 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 164 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); 165 166 /* start polling for touch_det to detect release */ 167 schedule_delayed_work(&ts->work, msecs_to_jiffies(50)); 168 169 return IRQ_HANDLED; 170 } 171 172 static int stmpe_init_hw(struct stmpe_touch *ts) 173 { 174 int ret; 175 u8 adc_ctrl1, adc_ctrl1_mask, tsc_cfg, tsc_cfg_mask; 176 struct stmpe *stmpe = ts->stmpe; 177 struct device *dev = ts->dev; 178 179 ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC); 180 if (ret) { 181 dev_err(dev, "Could not enable clock for ADC and TS\n"); 182 return ret; 183 } 184 185 adc_ctrl1 = SAMPLE_TIME(ts->sample_time) | MOD_12B(ts->mod_12b) | 186 REF_SEL(ts->ref_sel); 187 adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff); 188 189 ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1, 190 adc_ctrl1_mask, adc_ctrl1); 191 if (ret) { 192 dev_err(dev, "Could not setup ADC\n"); 193 return ret; 194 } 195 196 ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2, 197 ADC_FREQ(0xff), ADC_FREQ(ts->adc_freq)); 198 if (ret) { 199 dev_err(dev, "Could not setup ADC\n"); 200 return ret; 201 } 202 203 tsc_cfg = AVE_CTRL(ts->ave_ctrl) | DET_DELAY(ts->touch_det_delay) | 204 SETTLING(ts->settling); 205 tsc_cfg_mask = AVE_CTRL(0xff) | DET_DELAY(0xff) | SETTLING(0xff); 206 207 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg); 208 if (ret) { 209 dev_err(dev, "Could not config touch\n"); 210 return ret; 211 } 212 213 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z, 214 FRACTION_Z(0xff), FRACTION_Z(ts->fraction_z)); 215 if (ret) { 216 dev_err(dev, "Could not config touch\n"); 217 return ret; 218 } 219 220 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE, 221 I_DRIVE(0xff), I_DRIVE(ts->i_drive)); 222 if (ret) { 223 dev_err(dev, "Could not config touch\n"); 224 return ret; 225 } 226 227 /* set FIFO to 1 for single point reading */ 228 ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1); 229 if (ret) { 230 dev_err(dev, "Could not set FIFO\n"); 231 return ret; 232 } 233 234 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL, 235 OP_MODE(0xff), OP_MODE(OP_MOD_XYZ)); 236 if (ret) { 237 dev_err(dev, "Could not set mode\n"); 238 return ret; 239 } 240 241 return 0; 242 } 243 244 static int stmpe_ts_open(struct input_dev *dev) 245 { 246 struct stmpe_touch *ts = input_get_drvdata(dev); 247 int ret = 0; 248 249 ret = __stmpe_reset_fifo(ts->stmpe); 250 if (ret) 251 return ret; 252 253 return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 254 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); 255 } 256 257 static void stmpe_ts_close(struct input_dev *dev) 258 { 259 struct stmpe_touch *ts = input_get_drvdata(dev); 260 261 cancel_delayed_work_sync(&ts->work); 262 263 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 264 STMPE_TSC_CTRL_TSC_EN, 0); 265 } 266 267 static void stmpe_ts_get_platform_info(struct platform_device *pdev, 268 struct stmpe_touch *ts) 269 { 270 struct device_node *np = pdev->dev.of_node; 271 u32 val; 272 273 if (np) { 274 if (!of_property_read_u32(np, "st,sample-time", &val)) 275 ts->sample_time = val; 276 if (!of_property_read_u32(np, "st,mod-12b", &val)) 277 ts->mod_12b = val; 278 if (!of_property_read_u32(np, "st,ref-sel", &val)) 279 ts->ref_sel = val; 280 if (!of_property_read_u32(np, "st,adc-freq", &val)) 281 ts->adc_freq = val; 282 if (!of_property_read_u32(np, "st,ave-ctrl", &val)) 283 ts->ave_ctrl = val; 284 if (!of_property_read_u32(np, "st,touch-det-delay", &val)) 285 ts->touch_det_delay = val; 286 if (!of_property_read_u32(np, "st,settling", &val)) 287 ts->settling = val; 288 if (!of_property_read_u32(np, "st,fraction-z", &val)) 289 ts->fraction_z = val; 290 if (!of_property_read_u32(np, "st,i-drive", &val)) 291 ts->i_drive = val; 292 } 293 } 294 295 static int stmpe_input_probe(struct platform_device *pdev) 296 { 297 struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent); 298 struct stmpe_touch *ts; 299 struct input_dev *idev; 300 int error; 301 int ts_irq; 302 303 ts_irq = platform_get_irq_byname(pdev, "FIFO_TH"); 304 if (ts_irq < 0) 305 return ts_irq; 306 307 ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL); 308 if (!ts) 309 return -ENOMEM; 310 311 idev = devm_input_allocate_device(&pdev->dev); 312 if (!idev) 313 return -ENOMEM; 314 315 platform_set_drvdata(pdev, ts); 316 ts->stmpe = stmpe; 317 ts->idev = idev; 318 ts->dev = &pdev->dev; 319 320 stmpe_ts_get_platform_info(pdev, ts); 321 322 INIT_DELAYED_WORK(&ts->work, stmpe_work); 323 324 error = devm_request_threaded_irq(&pdev->dev, ts_irq, 325 NULL, stmpe_ts_handler, 326 IRQF_ONESHOT, STMPE_TS_NAME, ts); 327 if (error) { 328 dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq); 329 return error; 330 } 331 332 error = stmpe_init_hw(ts); 333 if (error) 334 return error; 335 336 idev->name = STMPE_TS_NAME; 337 idev->phys = STMPE_TS_NAME"/input0"; 338 idev->id.bustype = BUS_I2C; 339 340 idev->open = stmpe_ts_open; 341 idev->close = stmpe_ts_close; 342 343 input_set_drvdata(idev, ts); 344 345 input_set_capability(idev, EV_KEY, BTN_TOUCH); 346 input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0); 347 input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0); 348 input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0); 349 350 error = input_register_device(idev); 351 if (error) { 352 dev_err(&pdev->dev, "Could not register input device\n"); 353 return error; 354 } 355 356 return 0; 357 } 358 359 static int stmpe_ts_remove(struct platform_device *pdev) 360 { 361 struct stmpe_touch *ts = platform_get_drvdata(pdev); 362 363 stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN); 364 365 return 0; 366 } 367 368 static struct platform_driver stmpe_ts_driver = { 369 .driver = { 370 .name = STMPE_TS_NAME, 371 }, 372 .probe = stmpe_input_probe, 373 .remove = stmpe_ts_remove, 374 }; 375 module_platform_driver(stmpe_ts_driver); 376 377 static const struct of_device_id stmpe_ts_ids[] = { 378 { .compatible = "st,stmpe-ts", }, 379 { }, 380 }; 381 MODULE_DEVICE_TABLE(of, stmpe_ts_ids); 382 383 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); 384 MODULE_DESCRIPTION("STMPEXXX touchscreen driver"); 385 MODULE_LICENSE("GPL"); 386