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/slab.h> 18 #include <linux/delay.h> 19 #include <linux/i2c.h> 20 #include <linux/workqueue.h> 21 22 #include <linux/mfd/stmpe.h> 23 24 /* Register layouts and functionalities are identical on all stmpexxx variants 25 * with touchscreen controller 26 */ 27 #define STMPE_REG_INT_STA 0x0B 28 #define STMPE_REG_TSC_CTRL 0x40 29 #define STMPE_REG_TSC_CFG 0x41 30 #define STMPE_REG_FIFO_TH 0x4A 31 #define STMPE_REG_FIFO_STA 0x4B 32 #define STMPE_REG_FIFO_SIZE 0x4C 33 #define STMPE_REG_TSC_DATA_XYZ 0x52 34 #define STMPE_REG_TSC_FRACTION_Z 0x56 35 #define STMPE_REG_TSC_I_DRIVE 0x58 36 37 #define OP_MOD_XYZ 0 38 39 #define STMPE_TSC_CTRL_TSC_EN (1<<0) 40 41 #define STMPE_FIFO_STA_RESET (1<<0) 42 43 #define STMPE_IRQ_TOUCH_DET 0 44 45 #define STMPE_TS_NAME "stmpe-ts" 46 #define XY_MASK 0xfff 47 48 /** 49 * struct stmpe_touch - stmpe811 touch screen controller state 50 * @stmpe: pointer back to STMPE MFD container 51 * @idev: registered input device 52 * @work: a work item used to scan the device 53 * @dev: a pointer back to the MFD cell struct device* 54 * @ave_ctrl: Sample average control 55 * (0 -> 1 sample, 1 -> 2 samples, 2 -> 4 samples, 3 -> 8 samples) 56 * @touch_det_delay: Touch detect interrupt delay 57 * (0 -> 10 us, 1 -> 50 us, 2 -> 100 us, 3 -> 500 us, 58 * 4-> 1 ms, 5 -> 5 ms, 6 -> 10 ms, 7 -> 50 ms) 59 * recommended is 3 60 * @settling: Panel driver settling time 61 * (0 -> 10 us, 1 -> 100 us, 2 -> 500 us, 3 -> 1 ms, 62 * 4 -> 5 ms, 5 -> 10 ms, 6 for 50 ms, 7 -> 100 ms) 63 * recommended is 2 64 * @fraction_z: Length of the fractional part in z 65 * (fraction_z ([0..7]) = Count of the fractional part) 66 * recommended is 7 67 * @i_drive: current limit value of the touchscreen drivers 68 * (0 -> 20 mA typical 35 mA max, 1 -> 50 mA typical 80 mA max) 69 */ 70 struct stmpe_touch { 71 struct stmpe *stmpe; 72 struct input_dev *idev; 73 struct delayed_work work; 74 struct device *dev; 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 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 ret = stmpe811_adc_common_init(stmpe); 186 if (ret) { 187 stmpe_disable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC); 188 return ret; 189 } 190 191 tsc_cfg = STMPE_AVE_CTRL(ts->ave_ctrl) | 192 STMPE_DET_DELAY(ts->touch_det_delay) | 193 STMPE_SETTLING(ts->settling); 194 tsc_cfg_mask = STMPE_AVE_CTRL(0xff) | STMPE_DET_DELAY(0xff) | 195 STMPE_SETTLING(0xff); 196 197 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg); 198 if (ret) { 199 dev_err(dev, "Could not config touch\n"); 200 return ret; 201 } 202 203 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z, 204 STMPE_FRACTION_Z(0xff), STMPE_FRACTION_Z(ts->fraction_z)); 205 if (ret) { 206 dev_err(dev, "Could not config touch\n"); 207 return ret; 208 } 209 210 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE, 211 STMPE_I_DRIVE(0xff), STMPE_I_DRIVE(ts->i_drive)); 212 if (ret) { 213 dev_err(dev, "Could not config touch\n"); 214 return ret; 215 } 216 217 /* set FIFO to 1 for single point reading */ 218 ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1); 219 if (ret) { 220 dev_err(dev, "Could not set FIFO\n"); 221 return ret; 222 } 223 224 ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL, 225 STMPE_OP_MODE(0xff), STMPE_OP_MODE(OP_MOD_XYZ)); 226 if (ret) { 227 dev_err(dev, "Could not set mode\n"); 228 return ret; 229 } 230 231 return 0; 232 } 233 234 static int stmpe_ts_open(struct input_dev *dev) 235 { 236 struct stmpe_touch *ts = input_get_drvdata(dev); 237 int ret = 0; 238 239 ret = __stmpe_reset_fifo(ts->stmpe); 240 if (ret) 241 return ret; 242 243 return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 244 STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); 245 } 246 247 static void stmpe_ts_close(struct input_dev *dev) 248 { 249 struct stmpe_touch *ts = input_get_drvdata(dev); 250 251 cancel_delayed_work_sync(&ts->work); 252 253 stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, 254 STMPE_TSC_CTRL_TSC_EN, 0); 255 } 256 257 static void stmpe_ts_get_platform_info(struct platform_device *pdev, 258 struct stmpe_touch *ts) 259 { 260 struct device_node *np = pdev->dev.of_node; 261 u32 val; 262 263 if (np) { 264 if (!of_property_read_u32(np, "st,sample-time", &val)) 265 ts->stmpe->sample_time = val; 266 if (!of_property_read_u32(np, "st,mod-12b", &val)) 267 ts->stmpe->mod_12b = val; 268 if (!of_property_read_u32(np, "st,ref-sel", &val)) 269 ts->stmpe->ref_sel = val; 270 if (!of_property_read_u32(np, "st,adc-freq", &val)) 271 ts->stmpe->adc_freq = val; 272 if (!of_property_read_u32(np, "st,ave-ctrl", &val)) 273 ts->ave_ctrl = val; 274 if (!of_property_read_u32(np, "st,touch-det-delay", &val)) 275 ts->touch_det_delay = val; 276 if (!of_property_read_u32(np, "st,settling", &val)) 277 ts->settling = val; 278 if (!of_property_read_u32(np, "st,fraction-z", &val)) 279 ts->fraction_z = val; 280 if (!of_property_read_u32(np, "st,i-drive", &val)) 281 ts->i_drive = val; 282 } 283 } 284 285 static int stmpe_input_probe(struct platform_device *pdev) 286 { 287 struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent); 288 struct stmpe_touch *ts; 289 struct input_dev *idev; 290 int error; 291 int ts_irq; 292 293 ts_irq = platform_get_irq_byname(pdev, "FIFO_TH"); 294 if (ts_irq < 0) 295 return ts_irq; 296 297 ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL); 298 if (!ts) 299 return -ENOMEM; 300 301 idev = devm_input_allocate_device(&pdev->dev); 302 if (!idev) 303 return -ENOMEM; 304 305 platform_set_drvdata(pdev, ts); 306 ts->stmpe = stmpe; 307 ts->idev = idev; 308 ts->dev = &pdev->dev; 309 310 stmpe_ts_get_platform_info(pdev, ts); 311 312 INIT_DELAYED_WORK(&ts->work, stmpe_work); 313 314 error = devm_request_threaded_irq(&pdev->dev, ts_irq, 315 NULL, stmpe_ts_handler, 316 IRQF_ONESHOT, STMPE_TS_NAME, ts); 317 if (error) { 318 dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq); 319 return error; 320 } 321 322 error = stmpe_init_hw(ts); 323 if (error) 324 return error; 325 326 idev->name = STMPE_TS_NAME; 327 idev->phys = STMPE_TS_NAME"/input0"; 328 idev->id.bustype = BUS_I2C; 329 330 idev->open = stmpe_ts_open; 331 idev->close = stmpe_ts_close; 332 333 input_set_drvdata(idev, ts); 334 335 input_set_capability(idev, EV_KEY, BTN_TOUCH); 336 input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0); 337 input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0); 338 input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0); 339 340 error = input_register_device(idev); 341 if (error) { 342 dev_err(&pdev->dev, "Could not register input device\n"); 343 return error; 344 } 345 346 return 0; 347 } 348 349 static int stmpe_ts_remove(struct platform_device *pdev) 350 { 351 struct stmpe_touch *ts = platform_get_drvdata(pdev); 352 353 stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN); 354 355 return 0; 356 } 357 358 static struct platform_driver stmpe_ts_driver = { 359 .driver = { 360 .name = STMPE_TS_NAME, 361 }, 362 .probe = stmpe_input_probe, 363 .remove = stmpe_ts_remove, 364 }; 365 module_platform_driver(stmpe_ts_driver); 366 367 static const struct of_device_id stmpe_ts_ids[] = { 368 { .compatible = "st,stmpe-ts", }, 369 { }, 370 }; 371 MODULE_DEVICE_TABLE(of, stmpe_ts_ids); 372 373 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); 374 MODULE_DESCRIPTION("STMPEXXX touchscreen driver"); 375 MODULE_LICENSE("GPL"); 376