1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * STMicroelectronics STMPE811 Touchscreen Driver 4 * 5 * (C) 2010 Luotao Fu <l.fu@pengutronix.de> 6 * All rights reserved. 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <linux/sched.h> 12 #include <linux/interrupt.h> 13 #include <linux/device.h> 14 #include <linux/of.h> 15 #include <linux/platform_device.h> 16 #include <linux/input.h> 17 #include <linux/input/touchscreen.h> 18 #include <linux/slab.h> 19 #include <linux/delay.h> 20 #include <linux/i2c.h> 21 #include <linux/workqueue.h> 22 23 #include <linux/mfd/stmpe.h> 24 25 /* Register layouts and functionalities are identical on all stmpexxx variants 26 * with touchscreen controller 27 */ 28 #define STMPE_REG_INT_STA 0x0B 29 #define STMPE_REG_TSC_CTRL 0x40 30 #define STMPE_REG_TSC_CFG 0x41 31 #define STMPE_REG_FIFO_TH 0x4A 32 #define STMPE_REG_FIFO_STA 0x4B 33 #define STMPE_REG_FIFO_SIZE 0x4C 34 #define STMPE_REG_TSC_DATA_XYZ 0x52 35 #define STMPE_REG_TSC_FRACTION_Z 0x56 36 #define STMPE_REG_TSC_I_DRIVE 0x58 37 38 #define OP_MOD_XYZ 0 39 40 #define STMPE_TSC_CTRL_TSC_EN (1<<0) 41 42 #define STMPE_FIFO_STA_RESET (1<<0) 43 44 #define STMPE_IRQ_TOUCH_DET 0 45 46 #define STMPE_TS_NAME "stmpe-ts" 47 #define XY_MASK 0xfff 48 49 /** 50 * struct stmpe_touch - stmpe811 touch screen controller state 51 * @stmpe: pointer back to STMPE MFD container 52 * @idev: registered input device 53 * @work: a work item used to scan the device 54 * @dev: a pointer back to the MFD cell struct device* 55 * @ave_ctrl: Sample average control 56 * (0 -> 1 sample, 1 -> 2 samples, 2 -> 4 samples, 3 -> 8 samples) 57 * @touch_det_delay: Touch detect interrupt delay 58 * (0 -> 10 us, 1 -> 50 us, 2 -> 100 us, 3 -> 500 us, 59 * 4-> 1 ms, 5 -> 5 ms, 6 -> 10 ms, 7 -> 50 ms) 60 * recommended is 3 61 * @settling: Panel driver settling time 62 * (0 -> 10 us, 1 -> 100 us, 2 -> 500 us, 3 -> 1 ms, 63 * 4 -> 5 ms, 5 -> 10 ms, 6 for 50 ms, 7 -> 100 ms) 64 * recommended is 2 65 * @fraction_z: Length of the fractional part in z 66 * (fraction_z ([0..7]) = Count of the fractional part) 67 * recommended is 7 68 * @i_drive: current limit value of the touchscreen drivers 69 * (0 -> 20 mA typical 35 mA max, 1 -> 50 mA typical 80 mA max) 70 */ 71 struct stmpe_touch { 72 struct stmpe *stmpe; 73 struct input_dev *idev; 74 struct delayed_work work; 75 struct device *dev; 76 struct touchscreen_properties prop; 77 u8 ave_ctrl; 78 u8 touch_det_delay; 79 u8 settling; 80 u8 fraction_z; 81 u8 i_drive; 82 }; 83 84 static int __stmpe_reset_fifo(struct stmpe *stmpe) 85 { 86 int ret; 87 88 ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, 89 STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET); 90 if (ret) 91 return ret; 92 93 return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, 94 STMPE_FIFO_STA_RESET, 0); 95 } 96 97 static void stmpe_work(struct work_struct *work) 98 { 99 int int_sta; 100 u32 timeout = 40; 101 102 struct stmpe_touch *ts = 103 container_of(work, struct stmpe_touch, work.work); 104 105 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); 106 107 /* 108 * touch_det sometimes get desasserted or just get stuck. This appears 109 * to be a silicon bug, We still have to clearify this with the 110 * manufacture. As a workaround We release the key anyway if the 111 * touch_det keeps coming in after 4ms, while the FIFO contains no value 112 * during the whole time. 113 */ 114 while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) { 115 timeout--; 116 int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); 117 udelay(100); 118 } 119 120 /* reset the FIFO before we report release event */ 121 __stmpe_reset_fifo(ts->stmpe); 122 123 input_report_abs(ts->idev, ABS_PRESSURE, 0); 124 input_report_key(ts->idev, BTN_TOUCH, 0); 125 input_sync(ts->idev); 126 } 127 128 static irqreturn_t stmpe_ts_handler(int irq, void *data) 129 { 130 u8 data_set[4]; 131 int x, y, z; 132 struct stmpe_touch *ts = data; 133 134 /* 135 * Cancel scheduled polling for release if we have new value 136 * available. Wait if the polling is already running. 137 */ 138 cancel_delayed_work_sync(&ts->work); 139 140 /* 141 * The FIFO sometimes just crashes and stops generating interrupts. This 142 * appears to be a silicon bug. We still have to clearify this with 143 * the manufacture. As a workaround we disable the TSC while we are 144 * collecting data and flush the FIFO after reading 145 */ 146 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 147 STMPE_TSC_CTRL_TSC_EN, 0); 148 149 stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set); 150 151 x = (data_set[0] << 4) | (data_set[1] >> 4); 152 y = ((data_set[1] & 0xf) << 8) | data_set[2]; 153 z = data_set[3]; 154 155 touchscreen_report_pos(ts->idev, &ts->prop, x, y, false); 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, msecs_to_jiffies(50)); 169 170 return IRQ_HANDLED; 171 } 172 173 static int stmpe_init_hw(struct stmpe_touch *ts) 174 { 175 int ret; 176 u8 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 ret = stmpe811_adc_common_init(stmpe); 187 if (ret) { 188 stmpe_disable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC); 189 return ret; 190 } 191 192 tsc_cfg = STMPE_AVE_CTRL(ts->ave_ctrl) | 193 STMPE_DET_DELAY(ts->touch_det_delay) | 194 STMPE_SETTLING(ts->settling); 195 tsc_cfg_mask = STMPE_AVE_CTRL(0xff) | STMPE_DET_DELAY(0xff) | 196 STMPE_SETTLING(0xff); 197 198 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg); 199 if (ret) { 200 dev_err(dev, "Could not config touch\n"); 201 return ret; 202 } 203 204 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z, 205 STMPE_FRACTION_Z(0xff), STMPE_FRACTION_Z(ts->fraction_z)); 206 if (ret) { 207 dev_err(dev, "Could not config touch\n"); 208 return ret; 209 } 210 211 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE, 212 STMPE_I_DRIVE(0xff), STMPE_I_DRIVE(ts->i_drive)); 213 if (ret) { 214 dev_err(dev, "Could not config touch\n"); 215 return ret; 216 } 217 218 /* set FIFO to 1 for single point reading */ 219 ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1); 220 if (ret) { 221 dev_err(dev, "Could not set FIFO\n"); 222 return ret; 223 } 224 225 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL, 226 STMPE_OP_MODE(0xff), STMPE_OP_MODE(OP_MOD_XYZ)); 227 if (ret) { 228 dev_err(dev, "Could not set mode\n"); 229 return ret; 230 } 231 232 return 0; 233 } 234 235 static int stmpe_ts_open(struct input_dev *dev) 236 { 237 struct stmpe_touch *ts = input_get_drvdata(dev); 238 int ret = 0; 239 240 ret = __stmpe_reset_fifo(ts->stmpe); 241 if (ret) 242 return ret; 243 244 return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 245 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); 246 } 247 248 static void stmpe_ts_close(struct input_dev *dev) 249 { 250 struct stmpe_touch *ts = input_get_drvdata(dev); 251 252 cancel_delayed_work_sync(&ts->work); 253 254 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 255 STMPE_TSC_CTRL_TSC_EN, 0); 256 } 257 258 static void stmpe_ts_get_platform_info(struct platform_device *pdev, 259 struct stmpe_touch *ts) 260 { 261 struct device_node *np = pdev->dev.of_node; 262 u32 val; 263 264 if (np) { 265 if (!of_property_read_u32(np, "st,sample-time", &val)) 266 ts->stmpe->sample_time = val; 267 if (!of_property_read_u32(np, "st,mod-12b", &val)) 268 ts->stmpe->mod_12b = val; 269 if (!of_property_read_u32(np, "st,ref-sel", &val)) 270 ts->stmpe->ref_sel = val; 271 if (!of_property_read_u32(np, "st,adc-freq", &val)) 272 ts->stmpe->adc_freq = val; 273 if (!of_property_read_u32(np, "st,ave-ctrl", &val)) 274 ts->ave_ctrl = val; 275 if (!of_property_read_u32(np, "st,touch-det-delay", &val)) 276 ts->touch_det_delay = val; 277 if (!of_property_read_u32(np, "st,settling", &val)) 278 ts->settling = val; 279 if (!of_property_read_u32(np, "st,fraction-z", &val)) 280 ts->fraction_z = val; 281 if (!of_property_read_u32(np, "st,i-drive", &val)) 282 ts->i_drive = val; 283 } 284 } 285 286 static int stmpe_input_probe(struct platform_device *pdev) 287 { 288 struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent); 289 struct stmpe_touch *ts; 290 struct input_dev *idev; 291 int error; 292 int ts_irq; 293 294 ts_irq = platform_get_irq_byname(pdev, "FIFO_TH"); 295 if (ts_irq < 0) 296 return ts_irq; 297 298 ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL); 299 if (!ts) 300 return -ENOMEM; 301 302 idev = devm_input_allocate_device(&pdev->dev); 303 if (!idev) 304 return -ENOMEM; 305 306 platform_set_drvdata(pdev, ts); 307 ts->stmpe = stmpe; 308 ts->idev = idev; 309 ts->dev = &pdev->dev; 310 311 stmpe_ts_get_platform_info(pdev, ts); 312 313 INIT_DELAYED_WORK(&ts->work, stmpe_work); 314 315 error = devm_request_threaded_irq(&pdev->dev, ts_irq, 316 NULL, stmpe_ts_handler, 317 IRQF_ONESHOT, STMPE_TS_NAME, ts); 318 if (error) { 319 dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq); 320 return error; 321 } 322 323 error = stmpe_init_hw(ts); 324 if (error) 325 return error; 326 327 idev->name = STMPE_TS_NAME; 328 idev->phys = STMPE_TS_NAME"/input0"; 329 idev->id.bustype = BUS_I2C; 330 331 idev->open = stmpe_ts_open; 332 idev->close = stmpe_ts_close; 333 334 input_set_drvdata(idev, ts); 335 336 input_set_capability(idev, EV_KEY, BTN_TOUCH); 337 input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0); 338 input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0); 339 input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0); 340 341 touchscreen_parse_properties(idev, false, &ts->prop); 342 343 error = input_register_device(idev); 344 if (error) { 345 dev_err(&pdev->dev, "Could not register input device\n"); 346 return error; 347 } 348 349 return 0; 350 } 351 352 static int stmpe_ts_remove(struct platform_device *pdev) 353 { 354 struct stmpe_touch *ts = platform_get_drvdata(pdev); 355 356 stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN); 357 358 return 0; 359 } 360 361 static struct platform_driver stmpe_ts_driver = { 362 .driver = { 363 .name = STMPE_TS_NAME, 364 }, 365 .probe = stmpe_input_probe, 366 .remove = stmpe_ts_remove, 367 }; 368 module_platform_driver(stmpe_ts_driver); 369 370 static const struct of_device_id stmpe_ts_ids[] = { 371 { .compatible = "st,stmpe-ts", }, 372 { }, 373 }; 374 MODULE_DEVICE_TABLE(of, stmpe_ts_ids); 375 376 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); 377 MODULE_DESCRIPTION("STMPEXXX touchscreen driver"); 378 MODULE_LICENSE("GPL"); 379