1 /* 2 * Allwinner sunxi resistive touchscreen controller driver 3 * 4 * Copyright (C) 2013 - 2014 Hans de Goede <hdegoede@redhat.com> 5 * 6 * The hwmon parts are based on work by Corentin LABBE which is: 7 * Copyright (C) 2013 Corentin LABBE <clabbe.montjoie@gmail.com> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 */ 19 20 /* 21 * The sun4i-ts controller is capable of detecting a second touch, but when a 22 * second touch is present then the accuracy becomes so bad the reported touch 23 * location is not useable. 24 * 25 * The original android driver contains some complicated heuristics using the 26 * aprox. distance between the 2 touches to see if the user is making a pinch 27 * open / close movement, and then reports emulated multi-touch events around 28 * the last touch coordinate (as the dual-touch coordinates are worthless). 29 * 30 * These kinds of heuristics are just asking for trouble (and don't belong 31 * in the kernel). So this driver offers straight forward, reliable single 32 * touch functionality only. 33 */ 34 35 #include <linux/err.h> 36 #include <linux/hwmon.h> 37 #include <linux/thermal.h> 38 #include <linux/init.h> 39 #include <linux/input.h> 40 #include <linux/interrupt.h> 41 #include <linux/io.h> 42 #include <linux/module.h> 43 #include <linux/of_platform.h> 44 #include <linux/platform_device.h> 45 #include <linux/slab.h> 46 47 #define TP_CTRL0 0x00 48 #define TP_CTRL1 0x04 49 #define TP_CTRL2 0x08 50 #define TP_CTRL3 0x0c 51 #define TP_INT_FIFOC 0x10 52 #define TP_INT_FIFOS 0x14 53 #define TP_TPR 0x18 54 #define TP_CDAT 0x1c 55 #define TEMP_DATA 0x20 56 #define TP_DATA 0x24 57 58 /* TP_CTRL0 bits */ 59 #define ADC_FIRST_DLY(x) ((x) << 24) /* 8 bits */ 60 #define ADC_FIRST_DLY_MODE(x) ((x) << 23) 61 #define ADC_CLK_SEL(x) ((x) << 22) 62 #define ADC_CLK_DIV(x) ((x) << 20) /* 3 bits */ 63 #define FS_DIV(x) ((x) << 16) /* 4 bits */ 64 #define T_ACQ(x) ((x) << 0) /* 16 bits */ 65 66 /* TP_CTRL1 bits */ 67 #define STYLUS_UP_DEBOUN(x) ((x) << 12) /* 8 bits */ 68 #define STYLUS_UP_DEBOUN_EN(x) ((x) << 9) 69 #define TOUCH_PAN_CALI_EN(x) ((x) << 6) 70 #define TP_DUAL_EN(x) ((x) << 5) 71 #define TP_MODE_EN(x) ((x) << 4) 72 #define TP_ADC_SELECT(x) ((x) << 3) 73 #define ADC_CHAN_SELECT(x) ((x) << 0) /* 3 bits */ 74 75 /* on sun6i, bits 3~6 are left shifted by 1 to 4~7 */ 76 #define SUN6I_TP_MODE_EN(x) ((x) << 5) 77 78 /* TP_CTRL2 bits */ 79 #define TP_SENSITIVE_ADJUST(x) ((x) << 28) /* 4 bits */ 80 #define TP_MODE_SELECT(x) ((x) << 26) /* 2 bits */ 81 #define PRE_MEA_EN(x) ((x) << 24) 82 #define PRE_MEA_THRE_CNT(x) ((x) << 0) /* 24 bits */ 83 84 /* TP_CTRL3 bits */ 85 #define FILTER_EN(x) ((x) << 2) 86 #define FILTER_TYPE(x) ((x) << 0) /* 2 bits */ 87 88 /* TP_INT_FIFOC irq and fifo mask / control bits */ 89 #define TEMP_IRQ_EN(x) ((x) << 18) 90 #define OVERRUN_IRQ_EN(x) ((x) << 17) 91 #define DATA_IRQ_EN(x) ((x) << 16) 92 #define TP_DATA_XY_CHANGE(x) ((x) << 13) 93 #define FIFO_TRIG(x) ((x) << 8) /* 5 bits */ 94 #define DATA_DRQ_EN(x) ((x) << 7) 95 #define FIFO_FLUSH(x) ((x) << 4) 96 #define TP_UP_IRQ_EN(x) ((x) << 1) 97 #define TP_DOWN_IRQ_EN(x) ((x) << 0) 98 99 /* TP_INT_FIFOS irq and fifo status bits */ 100 #define TEMP_DATA_PENDING BIT(18) 101 #define FIFO_OVERRUN_PENDING BIT(17) 102 #define FIFO_DATA_PENDING BIT(16) 103 #define TP_IDLE_FLG BIT(2) 104 #define TP_UP_PENDING BIT(1) 105 #define TP_DOWN_PENDING BIT(0) 106 107 /* TP_TPR bits */ 108 #define TEMP_ENABLE(x) ((x) << 16) 109 #define TEMP_PERIOD(x) ((x) << 0) /* t = x * 256 * 16 / clkin */ 110 111 struct sun4i_ts_data { 112 struct device *dev; 113 struct input_dev *input; 114 struct thermal_zone_device *tz; 115 void __iomem *base; 116 unsigned int irq; 117 bool ignore_fifo_data; 118 int temp_data; 119 int temp_offset; 120 int temp_step; 121 }; 122 123 static void sun4i_ts_irq_handle_input(struct sun4i_ts_data *ts, u32 reg_val) 124 { 125 u32 x, y; 126 127 if (reg_val & FIFO_DATA_PENDING) { 128 x = readl(ts->base + TP_DATA); 129 y = readl(ts->base + TP_DATA); 130 /* The 1st location reported after an up event is unreliable */ 131 if (!ts->ignore_fifo_data) { 132 input_report_abs(ts->input, ABS_X, x); 133 input_report_abs(ts->input, ABS_Y, y); 134 /* 135 * The hardware has a separate down status bit, but 136 * that gets set before we get the first location, 137 * resulting in reporting a click on the old location. 138 */ 139 input_report_key(ts->input, BTN_TOUCH, 1); 140 input_sync(ts->input); 141 } else { 142 ts->ignore_fifo_data = false; 143 } 144 } 145 146 if (reg_val & TP_UP_PENDING) { 147 ts->ignore_fifo_data = true; 148 input_report_key(ts->input, BTN_TOUCH, 0); 149 input_sync(ts->input); 150 } 151 } 152 153 static irqreturn_t sun4i_ts_irq(int irq, void *dev_id) 154 { 155 struct sun4i_ts_data *ts = dev_id; 156 u32 reg_val; 157 158 reg_val = readl(ts->base + TP_INT_FIFOS); 159 160 if (reg_val & TEMP_DATA_PENDING) 161 ts->temp_data = readl(ts->base + TEMP_DATA); 162 163 if (ts->input) 164 sun4i_ts_irq_handle_input(ts, reg_val); 165 166 writel(reg_val, ts->base + TP_INT_FIFOS); 167 168 return IRQ_HANDLED; 169 } 170 171 static int sun4i_ts_open(struct input_dev *dev) 172 { 173 struct sun4i_ts_data *ts = input_get_drvdata(dev); 174 175 /* Flush, set trig level to 1, enable temp, data and up irqs */ 176 writel(TEMP_IRQ_EN(1) | DATA_IRQ_EN(1) | FIFO_TRIG(1) | FIFO_FLUSH(1) | 177 TP_UP_IRQ_EN(1), ts->base + TP_INT_FIFOC); 178 179 return 0; 180 } 181 182 static void sun4i_ts_close(struct input_dev *dev) 183 { 184 struct sun4i_ts_data *ts = input_get_drvdata(dev); 185 186 /* Deactivate all input IRQs */ 187 writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC); 188 } 189 190 static int sun4i_get_temp(const struct sun4i_ts_data *ts, long *temp) 191 { 192 /* No temp_data until the first irq */ 193 if (ts->temp_data == -1) 194 return -EAGAIN; 195 196 *temp = (ts->temp_data - ts->temp_offset) * ts->temp_step; 197 198 return 0; 199 } 200 201 static int sun4i_get_tz_temp(void *data, long *temp) 202 { 203 return sun4i_get_temp(data, temp); 204 } 205 206 static struct thermal_zone_of_device_ops sun4i_ts_tz_ops = { 207 .get_temp = sun4i_get_tz_temp, 208 }; 209 210 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr, 211 char *buf) 212 { 213 struct sun4i_ts_data *ts = dev_get_drvdata(dev); 214 long temp; 215 int error; 216 217 error = sun4i_get_temp(ts, &temp); 218 if (error) 219 return error; 220 221 return sprintf(buf, "%ld\n", temp); 222 } 223 224 static ssize_t show_temp_label(struct device *dev, 225 struct device_attribute *devattr, char *buf) 226 { 227 return sprintf(buf, "SoC temperature\n"); 228 } 229 230 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL); 231 static DEVICE_ATTR(temp1_label, S_IRUGO, show_temp_label, NULL); 232 233 static struct attribute *sun4i_ts_attrs[] = { 234 &dev_attr_temp1_input.attr, 235 &dev_attr_temp1_label.attr, 236 NULL 237 }; 238 ATTRIBUTE_GROUPS(sun4i_ts); 239 240 static int sun4i_ts_probe(struct platform_device *pdev) 241 { 242 struct sun4i_ts_data *ts; 243 struct device *dev = &pdev->dev; 244 struct device_node *np = dev->of_node; 245 struct device *hwmon; 246 int error; 247 u32 reg; 248 bool ts_attached; 249 250 ts = devm_kzalloc(dev, sizeof(struct sun4i_ts_data), GFP_KERNEL); 251 if (!ts) 252 return -ENOMEM; 253 254 ts->dev = dev; 255 ts->ignore_fifo_data = true; 256 ts->temp_data = -1; 257 if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts")) { 258 /* Allwinner SDK has temperature = -271 + (value / 6) (C) */ 259 ts->temp_offset = 1626; 260 ts->temp_step = 167; 261 } else if (of_device_is_compatible(np, "allwinner,sun4i-a10-ts")) { 262 /* 263 * The A10 temperature sensor has quite a wide spread, these 264 * parameters are based on the averaging of the calibration 265 * results of 4 completely different boards, with a spread of 266 * temp_step from 96 - 170 and temp_offset from 1758 - 3310. 267 */ 268 ts->temp_offset = 2570; 269 ts->temp_step = 133; 270 } else { 271 /* 272 * The user manuals do not contain the formula for calculating 273 * the temperature. The formula used here is from the AXP209, 274 * which is designed by X-Powers, an affiliate of Allwinner: 275 * 276 * temperature = -144.7 + (value * 0.1) 277 * 278 * Allwinner does not have any documentation whatsoever for 279 * this hardware. Moreover, it is claimed that the sensor 280 * is inaccurate and cannot work properly. 281 */ 282 ts->temp_offset = 1447; 283 ts->temp_step = 100; 284 } 285 286 ts_attached = of_property_read_bool(np, "allwinner,ts-attached"); 287 if (ts_attached) { 288 ts->input = devm_input_allocate_device(dev); 289 if (!ts->input) 290 return -ENOMEM; 291 292 ts->input->name = pdev->name; 293 ts->input->phys = "sun4i_ts/input0"; 294 ts->input->open = sun4i_ts_open; 295 ts->input->close = sun4i_ts_close; 296 ts->input->id.bustype = BUS_HOST; 297 ts->input->id.vendor = 0x0001; 298 ts->input->id.product = 0x0001; 299 ts->input->id.version = 0x0100; 300 ts->input->evbit[0] = BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS); 301 __set_bit(BTN_TOUCH, ts->input->keybit); 302 input_set_abs_params(ts->input, ABS_X, 0, 4095, 0, 0); 303 input_set_abs_params(ts->input, ABS_Y, 0, 4095, 0, 0); 304 input_set_drvdata(ts->input, ts); 305 } 306 307 ts->base = devm_ioremap_resource(dev, 308 platform_get_resource(pdev, IORESOURCE_MEM, 0)); 309 if (IS_ERR(ts->base)) 310 return PTR_ERR(ts->base); 311 312 ts->irq = platform_get_irq(pdev, 0); 313 error = devm_request_irq(dev, ts->irq, sun4i_ts_irq, 0, "sun4i-ts", ts); 314 if (error) 315 return error; 316 317 /* 318 * Select HOSC clk, clkin = clk / 6, adc samplefreq = clkin / 8192, 319 * t_acq = clkin / (16 * 64) 320 */ 321 writel(ADC_CLK_SEL(0) | ADC_CLK_DIV(2) | FS_DIV(7) | T_ACQ(63), 322 ts->base + TP_CTRL0); 323 324 /* 325 * sensitive_adjust = 15 : max, which is not all that sensitive, 326 * tp_mode = 0 : only x and y coordinates, as we don't use dual touch 327 */ 328 writel(TP_SENSITIVE_ADJUST(15) | TP_MODE_SELECT(0), 329 ts->base + TP_CTRL2); 330 331 /* Enable median filter, type 1 : 5/3 */ 332 writel(FILTER_EN(1) | FILTER_TYPE(1), ts->base + TP_CTRL3); 333 334 /* Enable temperature measurement, period 1953 (2 seconds) */ 335 writel(TEMP_ENABLE(1) | TEMP_PERIOD(1953), ts->base + TP_TPR); 336 337 /* 338 * Set stylus up debounce to aprox 10 ms, enable debounce, and 339 * finally enable tp mode. 340 */ 341 reg = STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1); 342 if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts")) 343 reg |= SUN6I_TP_MODE_EN(1); 344 else 345 reg |= TP_MODE_EN(1); 346 writel(reg, ts->base + TP_CTRL1); 347 348 /* 349 * The thermal core does not register hwmon devices for DT-based 350 * thermal zone sensors, such as this one. 351 */ 352 hwmon = devm_hwmon_device_register_with_groups(ts->dev, "sun4i_ts", 353 ts, sun4i_ts_groups); 354 if (IS_ERR(hwmon)) 355 return PTR_ERR(hwmon); 356 357 ts->tz = thermal_zone_of_sensor_register(ts->dev, 0, ts, 358 &sun4i_ts_tz_ops); 359 if (IS_ERR(ts->tz)) 360 ts->tz = NULL; 361 362 writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC); 363 364 if (ts_attached) { 365 error = input_register_device(ts->input); 366 if (error) { 367 writel(0, ts->base + TP_INT_FIFOC); 368 thermal_zone_of_sensor_unregister(ts->dev, ts->tz); 369 return error; 370 } 371 } 372 373 platform_set_drvdata(pdev, ts); 374 return 0; 375 } 376 377 static int sun4i_ts_remove(struct platform_device *pdev) 378 { 379 struct sun4i_ts_data *ts = platform_get_drvdata(pdev); 380 381 /* Explicit unregister to avoid open/close changing the imask later */ 382 if (ts->input) 383 input_unregister_device(ts->input); 384 385 thermal_zone_of_sensor_unregister(ts->dev, ts->tz); 386 387 /* Deactivate all IRQs */ 388 writel(0, ts->base + TP_INT_FIFOC); 389 390 return 0; 391 } 392 393 static const struct of_device_id sun4i_ts_of_match[] = { 394 { .compatible = "allwinner,sun4i-a10-ts", }, 395 { .compatible = "allwinner,sun5i-a13-ts", }, 396 { .compatible = "allwinner,sun6i-a31-ts", }, 397 { /* sentinel */ } 398 }; 399 MODULE_DEVICE_TABLE(of, sun4i_ts_of_match); 400 401 static struct platform_driver sun4i_ts_driver = { 402 .driver = { 403 .name = "sun4i-ts", 404 .of_match_table = of_match_ptr(sun4i_ts_of_match), 405 }, 406 .probe = sun4i_ts_probe, 407 .remove = sun4i_ts_remove, 408 }; 409 410 module_platform_driver(sun4i_ts_driver); 411 412 MODULE_DESCRIPTION("Allwinner sun4i resistive touchscreen controller driver"); 413 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 414 MODULE_LICENSE("GPL"); 415