1 /* 2 * Touch Screen driver for EETI's I2C connected touch screen panels 3 * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de> 4 * 5 * See EETI's software guide for the protocol specification: 6 * http://home.eeti.com.tw/web20/eg/guide.htm 7 * 8 * Based on migor_ts.c 9 * Copyright (c) 2008 Magnus Damm 10 * Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com> 11 * 12 * This file is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public 14 * License as published by the Free Software Foundation; either 15 * version 2 of the License, or (at your option) any later version. 16 * 17 * This file is distributed in the hope that it will be useful, 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 20 * General Public License for more details. 21 * 22 * You should have received a copy of the GNU General Public 23 * License along with this library; if not, write to the Free Software 24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 25 */ 26 27 #include <linux/module.h> 28 #include <linux/moduleparam.h> 29 #include <linux/kernel.h> 30 #include <linux/input.h> 31 #include <linux/interrupt.h> 32 #include <linux/i2c.h> 33 #include <linux/timer.h> 34 #include <linux/gpio.h> 35 #include <linux/input/eeti_ts.h> 36 #include <linux/slab.h> 37 38 static int flip_x; 39 module_param(flip_x, bool, 0644); 40 MODULE_PARM_DESC(flip_x, "flip x coordinate"); 41 42 static int flip_y; 43 module_param(flip_y, bool, 0644); 44 MODULE_PARM_DESC(flip_y, "flip y coordinate"); 45 46 struct eeti_ts_priv { 47 struct i2c_client *client; 48 struct input_dev *input; 49 struct work_struct work; 50 struct mutex mutex; 51 int irq, irq_active_high; 52 }; 53 54 #define EETI_TS_BITDEPTH (11) 55 #define EETI_MAXVAL ((1 << (EETI_TS_BITDEPTH + 1)) - 1) 56 57 #define REPORT_BIT_PRESSED (1 << 0) 58 #define REPORT_BIT_AD0 (1 << 1) 59 #define REPORT_BIT_AD1 (1 << 2) 60 #define REPORT_BIT_HAS_PRESSURE (1 << 6) 61 #define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH) 62 63 static inline int eeti_ts_irq_active(struct eeti_ts_priv *priv) 64 { 65 return gpio_get_value(irq_to_gpio(priv->irq)) == priv->irq_active_high; 66 } 67 68 static void eeti_ts_read(struct work_struct *work) 69 { 70 char buf[6]; 71 unsigned int x, y, res, pressed, to = 100; 72 struct eeti_ts_priv *priv = 73 container_of(work, struct eeti_ts_priv, work); 74 75 mutex_lock(&priv->mutex); 76 77 while (eeti_ts_irq_active(priv) && --to) 78 i2c_master_recv(priv->client, buf, sizeof(buf)); 79 80 if (!to) { 81 dev_err(&priv->client->dev, 82 "unable to clear IRQ - line stuck?\n"); 83 goto out; 84 } 85 86 /* drop non-report packets */ 87 if (!(buf[0] & 0x80)) 88 goto out; 89 90 pressed = buf[0] & REPORT_BIT_PRESSED; 91 res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1)); 92 x = buf[2] | (buf[1] << 8); 93 y = buf[4] | (buf[3] << 8); 94 95 /* fix the range to 11 bits */ 96 x >>= res - EETI_TS_BITDEPTH; 97 y >>= res - EETI_TS_BITDEPTH; 98 99 if (flip_x) 100 x = EETI_MAXVAL - x; 101 102 if (flip_y) 103 y = EETI_MAXVAL - y; 104 105 if (buf[0] & REPORT_BIT_HAS_PRESSURE) 106 input_report_abs(priv->input, ABS_PRESSURE, buf[5]); 107 108 input_report_abs(priv->input, ABS_X, x); 109 input_report_abs(priv->input, ABS_Y, y); 110 input_report_key(priv->input, BTN_TOUCH, !!pressed); 111 input_sync(priv->input); 112 113 out: 114 mutex_unlock(&priv->mutex); 115 } 116 117 static irqreturn_t eeti_ts_isr(int irq, void *dev_id) 118 { 119 struct eeti_ts_priv *priv = dev_id; 120 121 /* postpone I2C transactions as we are atomic */ 122 schedule_work(&priv->work); 123 124 return IRQ_HANDLED; 125 } 126 127 static int eeti_ts_open(struct input_dev *dev) 128 { 129 struct eeti_ts_priv *priv = input_get_drvdata(dev); 130 131 enable_irq(priv->irq); 132 133 /* Read the events once to arm the IRQ */ 134 eeti_ts_read(&priv->work); 135 136 return 0; 137 } 138 139 static void eeti_ts_close(struct input_dev *dev) 140 { 141 struct eeti_ts_priv *priv = input_get_drvdata(dev); 142 143 disable_irq(priv->irq); 144 cancel_work_sync(&priv->work); 145 } 146 147 static int __devinit eeti_ts_probe(struct i2c_client *client, 148 const struct i2c_device_id *idp) 149 { 150 struct eeti_ts_platform_data *pdata; 151 struct eeti_ts_priv *priv; 152 struct input_dev *input; 153 unsigned int irq_flags; 154 int err = -ENOMEM; 155 156 /* In contrast to what's described in the datasheet, there seems 157 * to be no way of probing the presence of that device using I2C 158 * commands. So we need to blindly believe it is there, and wait 159 * for interrupts to occur. */ 160 161 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 162 if (!priv) { 163 dev_err(&client->dev, "failed to allocate driver data\n"); 164 goto err0; 165 } 166 167 mutex_init(&priv->mutex); 168 input = input_allocate_device(); 169 170 if (!input) { 171 dev_err(&client->dev, "Failed to allocate input device.\n"); 172 goto err1; 173 } 174 175 input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 176 input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 177 178 input_set_abs_params(input, ABS_X, 0, EETI_MAXVAL, 0, 0); 179 input_set_abs_params(input, ABS_Y, 0, EETI_MAXVAL, 0, 0); 180 input_set_abs_params(input, ABS_PRESSURE, 0, 0xff, 0, 0); 181 182 input->name = client->name; 183 input->id.bustype = BUS_I2C; 184 input->dev.parent = &client->dev; 185 input->open = eeti_ts_open; 186 input->close = eeti_ts_close; 187 188 priv->client = client; 189 priv->input = input; 190 priv->irq = client->irq; 191 192 pdata = client->dev.platform_data; 193 194 if (pdata) 195 priv->irq_active_high = pdata->irq_active_high; 196 197 irq_flags = priv->irq_active_high ? 198 IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; 199 200 INIT_WORK(&priv->work, eeti_ts_read); 201 i2c_set_clientdata(client, priv); 202 input_set_drvdata(input, priv); 203 204 err = input_register_device(input); 205 if (err) 206 goto err1; 207 208 err = request_irq(priv->irq, eeti_ts_isr, irq_flags, 209 client->name, priv); 210 if (err) { 211 dev_err(&client->dev, "Unable to request touchscreen IRQ.\n"); 212 goto err2; 213 } 214 215 /* Disable the irq for now. It will be enabled once the input device 216 * is opened. */ 217 disable_irq(priv->irq); 218 219 device_init_wakeup(&client->dev, 0); 220 return 0; 221 222 err2: 223 input_unregister_device(input); 224 input = NULL; /* so we dont try to free it below */ 225 err1: 226 input_free_device(input); 227 i2c_set_clientdata(client, NULL); 228 kfree(priv); 229 err0: 230 return err; 231 } 232 233 static int __devexit eeti_ts_remove(struct i2c_client *client) 234 { 235 struct eeti_ts_priv *priv = i2c_get_clientdata(client); 236 237 free_irq(priv->irq, priv); 238 input_unregister_device(priv->input); 239 i2c_set_clientdata(client, NULL); 240 kfree(priv); 241 242 return 0; 243 } 244 245 #ifdef CONFIG_PM 246 static int eeti_ts_suspend(struct i2c_client *client, pm_message_t mesg) 247 { 248 struct eeti_ts_priv *priv = i2c_get_clientdata(client); 249 250 if (device_may_wakeup(&client->dev)) 251 enable_irq_wake(priv->irq); 252 253 return 0; 254 } 255 256 static int eeti_ts_resume(struct i2c_client *client) 257 { 258 struct eeti_ts_priv *priv = i2c_get_clientdata(client); 259 260 if (device_may_wakeup(&client->dev)) 261 disable_irq_wake(priv->irq); 262 263 return 0; 264 } 265 #else 266 #define eeti_ts_suspend NULL 267 #define eeti_ts_resume NULL 268 #endif 269 270 static const struct i2c_device_id eeti_ts_id[] = { 271 { "eeti_ts", 0 }, 272 { } 273 }; 274 MODULE_DEVICE_TABLE(i2c, eeti_ts_id); 275 276 static struct i2c_driver eeti_ts_driver = { 277 .driver = { 278 .name = "eeti_ts", 279 }, 280 .probe = eeti_ts_probe, 281 .remove = __devexit_p(eeti_ts_remove), 282 .suspend = eeti_ts_suspend, 283 .resume = eeti_ts_resume, 284 .id_table = eeti_ts_id, 285 }; 286 287 static int __init eeti_ts_init(void) 288 { 289 return i2c_add_driver(&eeti_ts_driver); 290 } 291 292 static void __exit eeti_ts_exit(void) 293 { 294 i2c_del_driver(&eeti_ts_driver); 295 } 296 297 MODULE_DESCRIPTION("EETI Touchscreen driver"); 298 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); 299 MODULE_LICENSE("GPL"); 300 301 module_init(eeti_ts_init); 302 module_exit(eeti_ts_exit); 303 304