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/init.h> 38 #include <linux/input.h> 39 #include <linux/interrupt.h> 40 #include <linux/io.h> 41 #include <linux/module.h> 42 #include <linux/of_platform.h> 43 #include <linux/platform_device.h> 44 #include <linux/slab.h> 45 46 #define TP_CTRL0 0x00 47 #define TP_CTRL1 0x04 48 #define TP_CTRL2 0x08 49 #define TP_CTRL3 0x0c 50 #define TP_INT_FIFOC 0x10 51 #define TP_INT_FIFOS 0x14 52 #define TP_TPR 0x18 53 #define TP_CDAT 0x1c 54 #define TEMP_DATA 0x20 55 #define TP_DATA 0x24 56 57 /* TP_CTRL0 bits */ 58 #define ADC_FIRST_DLY(x) ((x) << 24) /* 8 bits */ 59 #define ADC_FIRST_DLY_MODE(x) ((x) << 23) 60 #define ADC_CLK_SEL(x) ((x) << 22) 61 #define ADC_CLK_DIV(x) ((x) << 20) /* 3 bits */ 62 #define FS_DIV(x) ((x) << 16) /* 4 bits */ 63 #define T_ACQ(x) ((x) << 0) /* 16 bits */ 64 65 /* TP_CTRL1 bits */ 66 #define STYLUS_UP_DEBOUN(x) ((x) << 12) /* 8 bits */ 67 #define STYLUS_UP_DEBOUN_EN(x) ((x) << 9) 68 #define TOUCH_PAN_CALI_EN(x) ((x) << 6) 69 #define TP_DUAL_EN(x) ((x) << 5) 70 #define TP_MODE_EN(x) ((x) << 4) 71 #define TP_ADC_SELECT(x) ((x) << 3) 72 #define ADC_CHAN_SELECT(x) ((x) << 0) /* 3 bits */ 73 74 /* TP_CTRL2 bits */ 75 #define TP_SENSITIVE_ADJUST(x) ((x) << 28) /* 4 bits */ 76 #define TP_MODE_SELECT(x) ((x) << 26) /* 2 bits */ 77 #define PRE_MEA_EN(x) ((x) << 24) 78 #define PRE_MEA_THRE_CNT(x) ((x) << 0) /* 24 bits */ 79 80 /* TP_CTRL3 bits */ 81 #define FILTER_EN(x) ((x) << 2) 82 #define FILTER_TYPE(x) ((x) << 0) /* 2 bits */ 83 84 /* TP_INT_FIFOC irq and fifo mask / control bits */ 85 #define TEMP_IRQ_EN(x) ((x) << 18) 86 #define OVERRUN_IRQ_EN(x) ((x) << 17) 87 #define DATA_IRQ_EN(x) ((x) << 16) 88 #define TP_DATA_XY_CHANGE(x) ((x) << 13) 89 #define FIFO_TRIG(x) ((x) << 8) /* 5 bits */ 90 #define DATA_DRQ_EN(x) ((x) << 7) 91 #define FIFO_FLUSH(x) ((x) << 4) 92 #define TP_UP_IRQ_EN(x) ((x) << 1) 93 #define TP_DOWN_IRQ_EN(x) ((x) << 0) 94 95 /* TP_INT_FIFOS irq and fifo status bits */ 96 #define TEMP_DATA_PENDING BIT(18) 97 #define FIFO_OVERRUN_PENDING BIT(17) 98 #define FIFO_DATA_PENDING BIT(16) 99 #define TP_IDLE_FLG BIT(2) 100 #define TP_UP_PENDING BIT(1) 101 #define TP_DOWN_PENDING BIT(0) 102 103 /* TP_TPR bits */ 104 #define TEMP_ENABLE(x) ((x) << 16) 105 #define TEMP_PERIOD(x) ((x) << 0) /* t = x * 256 * 16 / clkin */ 106 107 struct sun4i_ts_data { 108 struct device *dev; 109 struct input_dev *input; 110 void __iomem *base; 111 unsigned int irq; 112 bool ignore_fifo_data; 113 int temp_data; 114 }; 115 116 static void sun4i_ts_irq_handle_input(struct sun4i_ts_data *ts, u32 reg_val) 117 { 118 u32 x, y; 119 120 if (reg_val & FIFO_DATA_PENDING) { 121 x = readl(ts->base + TP_DATA); 122 y = readl(ts->base + TP_DATA); 123 /* The 1st location reported after an up event is unreliable */ 124 if (!ts->ignore_fifo_data) { 125 input_report_abs(ts->input, ABS_X, x); 126 input_report_abs(ts->input, ABS_Y, y); 127 /* 128 * The hardware has a separate down status bit, but 129 * that gets set before we get the first location, 130 * resulting in reporting a click on the old location. 131 */ 132 input_report_key(ts->input, BTN_TOUCH, 1); 133 input_sync(ts->input); 134 } else { 135 ts->ignore_fifo_data = false; 136 } 137 } 138 139 if (reg_val & TP_UP_PENDING) { 140 ts->ignore_fifo_data = true; 141 input_report_key(ts->input, BTN_TOUCH, 0); 142 input_sync(ts->input); 143 } 144 } 145 146 static irqreturn_t sun4i_ts_irq(int irq, void *dev_id) 147 { 148 struct sun4i_ts_data *ts = dev_id; 149 u32 reg_val; 150 151 reg_val = readl(ts->base + TP_INT_FIFOS); 152 153 if (reg_val & TEMP_DATA_PENDING) 154 ts->temp_data = readl(ts->base + TEMP_DATA); 155 156 if (ts->input) 157 sun4i_ts_irq_handle_input(ts, reg_val); 158 159 writel(reg_val, ts->base + TP_INT_FIFOS); 160 161 return IRQ_HANDLED; 162 } 163 164 static int sun4i_ts_open(struct input_dev *dev) 165 { 166 struct sun4i_ts_data *ts = input_get_drvdata(dev); 167 168 /* Flush, set trig level to 1, enable temp, data and up irqs */ 169 writel(TEMP_IRQ_EN(1) | DATA_IRQ_EN(1) | FIFO_TRIG(1) | FIFO_FLUSH(1) | 170 TP_UP_IRQ_EN(1), ts->base + TP_INT_FIFOC); 171 172 return 0; 173 } 174 175 static void sun4i_ts_close(struct input_dev *dev) 176 { 177 struct sun4i_ts_data *ts = input_get_drvdata(dev); 178 179 /* Deactivate all input IRQs */ 180 writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC); 181 } 182 183 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr, 184 char *buf) 185 { 186 struct sun4i_ts_data *ts = dev_get_drvdata(dev); 187 188 /* No temp_data until the first irq */ 189 if (ts->temp_data == -1) 190 return -EAGAIN; 191 192 return sprintf(buf, "%d\n", (ts->temp_data - 1447) * 100); 193 } 194 195 static ssize_t show_temp_label(struct device *dev, 196 struct device_attribute *devattr, char *buf) 197 { 198 return sprintf(buf, "SoC temperature\n"); 199 } 200 201 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL); 202 static DEVICE_ATTR(temp1_label, S_IRUGO, show_temp_label, NULL); 203 204 static struct attribute *sun4i_ts_attrs[] = { 205 &dev_attr_temp1_input.attr, 206 &dev_attr_temp1_label.attr, 207 NULL 208 }; 209 ATTRIBUTE_GROUPS(sun4i_ts); 210 211 static int sun4i_ts_probe(struct platform_device *pdev) 212 { 213 struct sun4i_ts_data *ts; 214 struct device *dev = &pdev->dev; 215 struct device_node *np = dev->of_node; 216 struct device *hwmon; 217 int error; 218 bool ts_attached; 219 220 ts = devm_kzalloc(dev, sizeof(struct sun4i_ts_data), GFP_KERNEL); 221 if (!ts) 222 return -ENOMEM; 223 224 ts->dev = dev; 225 ts->ignore_fifo_data = true; 226 ts->temp_data = -1; 227 228 ts_attached = of_property_read_bool(np, "allwinner,ts-attached"); 229 if (ts_attached) { 230 ts->input = devm_input_allocate_device(dev); 231 if (!ts->input) 232 return -ENOMEM; 233 234 ts->input->name = pdev->name; 235 ts->input->phys = "sun4i_ts/input0"; 236 ts->input->open = sun4i_ts_open; 237 ts->input->close = sun4i_ts_close; 238 ts->input->id.bustype = BUS_HOST; 239 ts->input->id.vendor = 0x0001; 240 ts->input->id.product = 0x0001; 241 ts->input->id.version = 0x0100; 242 ts->input->evbit[0] = BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS); 243 __set_bit(BTN_TOUCH, ts->input->keybit); 244 input_set_abs_params(ts->input, ABS_X, 0, 4095, 0, 0); 245 input_set_abs_params(ts->input, ABS_Y, 0, 4095, 0, 0); 246 input_set_drvdata(ts->input, ts); 247 } 248 249 ts->base = devm_ioremap_resource(dev, 250 platform_get_resource(pdev, IORESOURCE_MEM, 0)); 251 if (IS_ERR(ts->base)) 252 return PTR_ERR(ts->base); 253 254 ts->irq = platform_get_irq(pdev, 0); 255 error = devm_request_irq(dev, ts->irq, sun4i_ts_irq, 0, "sun4i-ts", ts); 256 if (error) 257 return error; 258 259 /* 260 * Select HOSC clk, clkin = clk / 6, adc samplefreq = clkin / 8192, 261 * t_acq = clkin / (16 * 64) 262 */ 263 writel(ADC_CLK_SEL(0) | ADC_CLK_DIV(2) | FS_DIV(7) | T_ACQ(63), 264 ts->base + TP_CTRL0); 265 266 /* 267 * sensitive_adjust = 15 : max, which is not all that sensitive, 268 * tp_mode = 0 : only x and y coordinates, as we don't use dual touch 269 */ 270 writel(TP_SENSITIVE_ADJUST(15) | TP_MODE_SELECT(0), 271 ts->base + TP_CTRL2); 272 273 /* Enable median filter, type 1 : 5/3 */ 274 writel(FILTER_EN(1) | FILTER_TYPE(1), ts->base + TP_CTRL3); 275 276 /* Enable temperature measurement, period 1953 (2 seconds) */ 277 writel(TEMP_ENABLE(1) | TEMP_PERIOD(1953), ts->base + TP_TPR); 278 279 /* 280 * Set stylus up debounce to aprox 10 ms, enable debounce, and 281 * finally enable tp mode. 282 */ 283 writel(STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1) | TP_MODE_EN(1), 284 ts->base + TP_CTRL1); 285 286 hwmon = devm_hwmon_device_register_with_groups(ts->dev, "sun4i_ts", 287 ts, sun4i_ts_groups); 288 if (IS_ERR(hwmon)) 289 return PTR_ERR(hwmon); 290 291 writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC); 292 293 if (ts_attached) { 294 error = input_register_device(ts->input); 295 if (error) { 296 writel(0, ts->base + TP_INT_FIFOC); 297 return error; 298 } 299 } 300 301 platform_set_drvdata(pdev, ts); 302 return 0; 303 } 304 305 static int sun4i_ts_remove(struct platform_device *pdev) 306 { 307 struct sun4i_ts_data *ts = platform_get_drvdata(pdev); 308 309 /* Explicit unregister to avoid open/close changing the imask later */ 310 if (ts->input) 311 input_unregister_device(ts->input); 312 313 /* Deactivate all IRQs */ 314 writel(0, ts->base + TP_INT_FIFOC); 315 316 return 0; 317 } 318 319 static const struct of_device_id sun4i_ts_of_match[] = { 320 { .compatible = "allwinner,sun4i-a10-ts", }, 321 { /* sentinel */ } 322 }; 323 MODULE_DEVICE_TABLE(of, sun4i_ts_of_match); 324 325 static struct platform_driver sun4i_ts_driver = { 326 .driver = { 327 .name = "sun4i-ts", 328 .of_match_table = of_match_ptr(sun4i_ts_of_match), 329 }, 330 .probe = sun4i_ts_probe, 331 .remove = sun4i_ts_remove, 332 }; 333 334 module_platform_driver(sun4i_ts_driver); 335 336 MODULE_DESCRIPTION("Allwinner sun4i resistive touchscreen controller driver"); 337 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 338 MODULE_LICENSE("GPL"); 339