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_TSC_CTRL 0x40 34 #define STMPE_REG_TSC_CFG 0x41 35 #define STMPE_REG_FIFO_TH 0x4A 36 #define STMPE_REG_FIFO_STA 0x4B 37 #define STMPE_REG_FIFO_SIZE 0x4C 38 #define STMPE_REG_TSC_DATA_XYZ 0x52 39 #define STMPE_REG_TSC_FRACTION_Z 0x56 40 #define STMPE_REG_TSC_I_DRIVE 0x58 41 42 #define OP_MOD_XYZ 0 43 44 #define STMPE_TSC_CTRL_TSC_EN (1<<0) 45 46 #define STMPE_FIFO_STA_RESET (1<<0) 47 48 #define STMPE_IRQ_TOUCH_DET 0 49 50 #define STMPE_TS_NAME "stmpe-ts" 51 #define XY_MASK 0xfff 52 53 /** 54 * struct stmpe_touch - stmpe811 touch screen controller state 55 * @stmpe: pointer back to STMPE MFD container 56 * @idev: registered input device 57 * @work: a work item used to scan the device 58 * @dev: a pointer back to the MFD cell struct device* 59 * @ave_ctrl: Sample average control 60 * (0 -> 1 sample, 1 -> 2 samples, 2 -> 4 samples, 3 -> 8 samples) 61 * @touch_det_delay: Touch detect interrupt delay 62 * (0 -> 10 us, 1 -> 50 us, 2 -> 100 us, 3 -> 500 us, 63 * 4-> 1 ms, 5 -> 5 ms, 6 -> 10 ms, 7 -> 50 ms) 64 * recommended is 3 65 * @settling: Panel driver settling time 66 * (0 -> 10 us, 1 -> 100 us, 2 -> 500 us, 3 -> 1 ms, 67 * 4 -> 5 ms, 5 -> 10 ms, 6 for 50 ms, 7 -> 100 ms) 68 * recommended is 2 69 * @fraction_z: Length of the fractional part in z 70 * (fraction_z ([0..7]) = Count of the fractional part) 71 * recommended is 7 72 * @i_drive: current limit value of the touchscreen drivers 73 * (0 -> 20 mA typical 35 mA max, 1 -> 50 mA typical 80 mA max) 74 */ 75 struct stmpe_touch { 76 struct stmpe *stmpe; 77 struct input_dev *idev; 78 struct delayed_work work; 79 struct device *dev; 80 u8 ave_ctrl; 81 u8 touch_det_delay; 82 u8 settling; 83 u8 fraction_z; 84 u8 i_drive; 85 }; 86 87 static int __stmpe_reset_fifo(struct stmpe *stmpe) 88 { 89 int ret; 90 91 ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, 92 STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET); 93 if (ret) 94 return ret; 95 96 return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, 97 STMPE_FIFO_STA_RESET, 0); 98 } 99 100 static void stmpe_work(struct work_struct *work) 101 { 102 int int_sta; 103 u32 timeout = 40; 104 105 struct stmpe_touch *ts = 106 container_of(work, struct stmpe_touch, work.work); 107 108 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); 109 110 /* 111 * touch_det sometimes get desasserted or just get stuck. This appears 112 * to be a silicon bug, We still have to clearify this with the 113 * manufacture. As a workaround We release the key anyway if the 114 * touch_det keeps coming in after 4ms, while the FIFO contains no value 115 * during the whole time. 116 */ 117 while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) { 118 timeout--; 119 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); 120 udelay(100); 121 } 122 123 /* reset the FIFO before we report release event */ 124 __stmpe_reset_fifo(ts->stmpe); 125 126 input_report_abs(ts->idev, ABS_PRESSURE, 0); 127 input_report_key(ts->idev, BTN_TOUCH, 0); 128 input_sync(ts->idev); 129 } 130 131 static irqreturn_t stmpe_ts_handler(int irq, void *data) 132 { 133 u8 data_set[4]; 134 int x, y, z; 135 struct stmpe_touch *ts = data; 136 137 /* 138 * Cancel scheduled polling for release if we have new value 139 * available. Wait if the polling is already running. 140 */ 141 cancel_delayed_work_sync(&ts->work); 142 143 /* 144 * The FIFO sometimes just crashes and stops generating interrupts. This 145 * appears to be a silicon bug. We still have to clearify this with 146 * the manufacture. As a workaround we disable the TSC while we are 147 * collecting data and flush the FIFO after reading 148 */ 149 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 150 STMPE_TSC_CTRL_TSC_EN, 0); 151 152 stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set); 153 154 x = (data_set[0] << 4) | (data_set[1] >> 4); 155 y = ((data_set[1] & 0xf) << 8) | data_set[2]; 156 z = data_set[3]; 157 158 input_report_abs(ts->idev, ABS_X, x); 159 input_report_abs(ts->idev, ABS_Y, y); 160 input_report_abs(ts->idev, ABS_PRESSURE, z); 161 input_report_key(ts->idev, BTN_TOUCH, 1); 162 input_sync(ts->idev); 163 164 /* flush the FIFO after we have read out our values. */ 165 __stmpe_reset_fifo(ts->stmpe); 166 167 /* reenable the tsc */ 168 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 169 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); 170 171 /* start polling for touch_det to detect release */ 172 schedule_delayed_work(&ts->work, msecs_to_jiffies(50)); 173 174 return IRQ_HANDLED; 175 } 176 177 static int stmpe_init_hw(struct stmpe_touch *ts) 178 { 179 int ret; 180 u8 tsc_cfg, tsc_cfg_mask; 181 struct stmpe *stmpe = ts->stmpe; 182 struct device *dev = ts->dev; 183 184 ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC); 185 if (ret) { 186 dev_err(dev, "Could not enable clock for ADC and TS\n"); 187 return ret; 188 } 189 190 ret = stmpe811_adc_common_init(stmpe); 191 if (ret) { 192 stmpe_disable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC); 193 return ret; 194 } 195 196 tsc_cfg = STMPE_AVE_CTRL(ts->ave_ctrl) | 197 STMPE_DET_DELAY(ts->touch_det_delay) | 198 STMPE_SETTLING(ts->settling); 199 tsc_cfg_mask = STMPE_AVE_CTRL(0xff) | STMPE_DET_DELAY(0xff) | 200 STMPE_SETTLING(0xff); 201 202 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg); 203 if (ret) { 204 dev_err(dev, "Could not config touch\n"); 205 return ret; 206 } 207 208 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z, 209 STMPE_FRACTION_Z(0xff), STMPE_FRACTION_Z(ts->fraction_z)); 210 if (ret) { 211 dev_err(dev, "Could not config touch\n"); 212 return ret; 213 } 214 215 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE, 216 STMPE_I_DRIVE(0xff), STMPE_I_DRIVE(ts->i_drive)); 217 if (ret) { 218 dev_err(dev, "Could not config touch\n"); 219 return ret; 220 } 221 222 /* set FIFO to 1 for single point reading */ 223 ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1); 224 if (ret) { 225 dev_err(dev, "Could not set FIFO\n"); 226 return ret; 227 } 228 229 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL, 230 STMPE_OP_MODE(0xff), STMPE_OP_MODE(OP_MOD_XYZ)); 231 if (ret) { 232 dev_err(dev, "Could not set mode\n"); 233 return ret; 234 } 235 236 return 0; 237 } 238 239 static int stmpe_ts_open(struct input_dev *dev) 240 { 241 struct stmpe_touch *ts = input_get_drvdata(dev); 242 int ret = 0; 243 244 ret = __stmpe_reset_fifo(ts->stmpe); 245 if (ret) 246 return ret; 247 248 return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 249 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); 250 } 251 252 static void stmpe_ts_close(struct input_dev *dev) 253 { 254 struct stmpe_touch *ts = input_get_drvdata(dev); 255 256 cancel_delayed_work_sync(&ts->work); 257 258 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 259 STMPE_TSC_CTRL_TSC_EN, 0); 260 } 261 262 static void stmpe_ts_get_platform_info(struct platform_device *pdev, 263 struct stmpe_touch *ts) 264 { 265 struct device_node *np = pdev->dev.of_node; 266 u32 val; 267 268 if (np) { 269 if (!of_property_read_u32(np, "st,sample-time", &val)) 270 ts->stmpe->sample_time = val; 271 if (!of_property_read_u32(np, "st,mod-12b", &val)) 272 ts->stmpe->mod_12b = val; 273 if (!of_property_read_u32(np, "st,ref-sel", &val)) 274 ts->stmpe->ref_sel = val; 275 if (!of_property_read_u32(np, "st,adc-freq", &val)) 276 ts->stmpe->adc_freq = val; 277 if (!of_property_read_u32(np, "st,ave-ctrl", &val)) 278 ts->ave_ctrl = val; 279 if (!of_property_read_u32(np, "st,touch-det-delay", &val)) 280 ts->touch_det_delay = val; 281 if (!of_property_read_u32(np, "st,settling", &val)) 282 ts->settling = val; 283 if (!of_property_read_u32(np, "st,fraction-z", &val)) 284 ts->fraction_z = val; 285 if (!of_property_read_u32(np, "st,i-drive", &val)) 286 ts->i_drive = val; 287 } 288 } 289 290 static int stmpe_input_probe(struct platform_device *pdev) 291 { 292 struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent); 293 struct stmpe_touch *ts; 294 struct input_dev *idev; 295 int error; 296 int ts_irq; 297 298 ts_irq = platform_get_irq_byname(pdev, "FIFO_TH"); 299 if (ts_irq < 0) 300 return ts_irq; 301 302 ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL); 303 if (!ts) 304 return -ENOMEM; 305 306 idev = devm_input_allocate_device(&pdev->dev); 307 if (!idev) 308 return -ENOMEM; 309 310 platform_set_drvdata(pdev, ts); 311 ts->stmpe = stmpe; 312 ts->idev = idev; 313 ts->dev = &pdev->dev; 314 315 stmpe_ts_get_platform_info(pdev, ts); 316 317 INIT_DELAYED_WORK(&ts->work, stmpe_work); 318 319 error = devm_request_threaded_irq(&pdev->dev, ts_irq, 320 NULL, stmpe_ts_handler, 321 IRQF_ONESHOT, STMPE_TS_NAME, ts); 322 if (error) { 323 dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq); 324 return error; 325 } 326 327 error = stmpe_init_hw(ts); 328 if (error) 329 return error; 330 331 idev->name = STMPE_TS_NAME; 332 idev->phys = STMPE_TS_NAME"/input0"; 333 idev->id.bustype = BUS_I2C; 334 335 idev->open = stmpe_ts_open; 336 idev->close = stmpe_ts_close; 337 338 input_set_drvdata(idev, ts); 339 340 input_set_capability(idev, EV_KEY, BTN_TOUCH); 341 input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0); 342 input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0); 343 input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0); 344 345 error = input_register_device(idev); 346 if (error) { 347 dev_err(&pdev->dev, "Could not register input device\n"); 348 return error; 349 } 350 351 return 0; 352 } 353 354 static int stmpe_ts_remove(struct platform_device *pdev) 355 { 356 struct stmpe_touch *ts = platform_get_drvdata(pdev); 357 358 stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN); 359 360 return 0; 361 } 362 363 static struct platform_driver stmpe_ts_driver = { 364 .driver = { 365 .name = STMPE_TS_NAME, 366 }, 367 .probe = stmpe_input_probe, 368 .remove = stmpe_ts_remove, 369 }; 370 module_platform_driver(stmpe_ts_driver); 371 372 static const struct of_device_id stmpe_ts_ids[] = { 373 { .compatible = "st,stmpe-ts", }, 374 { }, 375 }; 376 MODULE_DEVICE_TABLE(of, stmpe_ts_ids); 377 378 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); 379 MODULE_DESCRIPTION("STMPEXXX touchscreen driver"); 380 MODULE_LICENSE("GPL"); 381