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