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 36 static int flip_x; 37 module_param(flip_x, bool, 0644); 38 MODULE_PARM_DESC(flip_x, "flip x coordinate"); 39 40 static int flip_y; 41 module_param(flip_y, bool, 0644); 42 MODULE_PARM_DESC(flip_y, "flip y coordinate"); 43 44 struct eeti_ts_priv { 45 struct i2c_client *client; 46 struct input_dev *input; 47 struct work_struct work; 48 struct mutex mutex; 49 int irq; 50 }; 51 52 #define EETI_TS_BITDEPTH (11) 53 #define EETI_MAXVAL ((1 << (EETI_TS_BITDEPTH + 1)) - 1) 54 55 #define REPORT_BIT_PRESSED (1 << 0) 56 #define REPORT_BIT_AD0 (1 << 1) 57 #define REPORT_BIT_AD1 (1 << 2) 58 #define REPORT_BIT_HAS_PRESSURE (1 << 6) 59 #define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH) 60 61 static void eeti_ts_read(struct work_struct *work) 62 { 63 char buf[6]; 64 unsigned int x, y, res, pressed, to = 100; 65 struct eeti_ts_priv *priv = 66 container_of(work, struct eeti_ts_priv, work); 67 68 mutex_lock(&priv->mutex); 69 70 while (!gpio_get_value(irq_to_gpio(priv->irq)) && --to) 71 i2c_master_recv(priv->client, buf, sizeof(buf)); 72 73 if (!to) { 74 dev_err(&priv->client->dev, 75 "unable to clear IRQ - line stuck?\n"); 76 goto out; 77 } 78 79 /* drop non-report packets */ 80 if (!(buf[0] & 0x80)) 81 goto out; 82 83 pressed = buf[0] & REPORT_BIT_PRESSED; 84 res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1)); 85 x = buf[2] | (buf[1] << 8); 86 y = buf[4] | (buf[3] << 8); 87 88 /* fix the range to 11 bits */ 89 x >>= res - EETI_TS_BITDEPTH; 90 y >>= res - EETI_TS_BITDEPTH; 91 92 if (flip_x) 93 x = EETI_MAXVAL - x; 94 95 if (flip_y) 96 y = EETI_MAXVAL - y; 97 98 if (buf[0] & REPORT_BIT_HAS_PRESSURE) 99 input_report_abs(priv->input, ABS_PRESSURE, buf[5]); 100 101 input_report_abs(priv->input, ABS_X, x); 102 input_report_abs(priv->input, ABS_Y, y); 103 input_report_key(priv->input, BTN_TOUCH, !!pressed); 104 input_sync(priv->input); 105 106 out: 107 mutex_unlock(&priv->mutex); 108 } 109 110 static irqreturn_t eeti_ts_isr(int irq, void *dev_id) 111 { 112 struct eeti_ts_priv *priv = dev_id; 113 114 /* postpone I2C transactions as we are atomic */ 115 schedule_work(&priv->work); 116 117 return IRQ_HANDLED; 118 } 119 120 static int eeti_ts_open(struct input_dev *dev) 121 { 122 struct eeti_ts_priv *priv = input_get_drvdata(dev); 123 124 enable_irq(priv->irq); 125 126 /* Read the events once to arm the IRQ */ 127 eeti_ts_read(&priv->work); 128 129 return 0; 130 } 131 132 static void eeti_ts_close(struct input_dev *dev) 133 { 134 struct eeti_ts_priv *priv = input_get_drvdata(dev); 135 136 disable_irq(priv->irq); 137 cancel_work_sync(&priv->work); 138 } 139 140 static int __devinit eeti_ts_probe(struct i2c_client *client, 141 const struct i2c_device_id *idp) 142 { 143 struct eeti_ts_priv *priv; 144 struct input_dev *input; 145 int err = -ENOMEM; 146 147 /* In contrast to what's described in the datasheet, there seems 148 * to be no way of probing the presence of that device using I2C 149 * commands. So we need to blindly believe it is there, and wait 150 * for interrupts to occur. */ 151 152 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 153 if (!priv) { 154 dev_err(&client->dev, "failed to allocate driver data\n"); 155 goto err0; 156 } 157 158 mutex_init(&priv->mutex); 159 input = input_allocate_device(); 160 161 if (!input) { 162 dev_err(&client->dev, "Failed to allocate input device.\n"); 163 goto err1; 164 } 165 166 input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 167 input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 168 169 input_set_abs_params(input, ABS_X, 0, EETI_MAXVAL, 0, 0); 170 input_set_abs_params(input, ABS_Y, 0, EETI_MAXVAL, 0, 0); 171 input_set_abs_params(input, ABS_PRESSURE, 0, 0xff, 0, 0); 172 173 input->name = client->name; 174 input->id.bustype = BUS_I2C; 175 input->dev.parent = &client->dev; 176 input->open = eeti_ts_open; 177 input->close = eeti_ts_close; 178 179 priv->client = client; 180 priv->input = input; 181 priv->irq = client->irq; 182 183 INIT_WORK(&priv->work, eeti_ts_read); 184 i2c_set_clientdata(client, priv); 185 input_set_drvdata(input, priv); 186 187 err = input_register_device(input); 188 if (err) 189 goto err1; 190 191 err = request_irq(priv->irq, eeti_ts_isr, IRQF_TRIGGER_FALLING, 192 client->name, priv); 193 if (err) { 194 dev_err(&client->dev, "Unable to request touchscreen IRQ.\n"); 195 goto err2; 196 } 197 198 /* Disable the irq for now. It will be enabled once the input device 199 * is opened. */ 200 disable_irq(priv->irq); 201 202 device_init_wakeup(&client->dev, 0); 203 return 0; 204 205 err2: 206 input_unregister_device(input); 207 input = NULL; /* so we dont try to free it below */ 208 err1: 209 input_free_device(input); 210 i2c_set_clientdata(client, NULL); 211 kfree(priv); 212 err0: 213 return err; 214 } 215 216 static int __devexit eeti_ts_remove(struct i2c_client *client) 217 { 218 struct eeti_ts_priv *priv = i2c_get_clientdata(client); 219 220 free_irq(priv->irq, priv); 221 input_unregister_device(priv->input); 222 i2c_set_clientdata(client, NULL); 223 kfree(priv); 224 225 return 0; 226 } 227 228 #ifdef CONFIG_PM 229 static int eeti_ts_suspend(struct i2c_client *client, pm_message_t mesg) 230 { 231 struct eeti_ts_priv *priv = i2c_get_clientdata(client); 232 233 if (device_may_wakeup(&client->dev)) 234 enable_irq_wake(priv->irq); 235 236 return 0; 237 } 238 239 static int eeti_ts_resume(struct i2c_client *client) 240 { 241 struct eeti_ts_priv *priv = i2c_get_clientdata(client); 242 243 if (device_may_wakeup(&client->dev)) 244 disable_irq_wake(priv->irq); 245 246 return 0; 247 } 248 #else 249 #define eeti_ts_suspend NULL 250 #define eeti_ts_resume NULL 251 #endif 252 253 static const struct i2c_device_id eeti_ts_id[] = { 254 { "eeti_ts", 0 }, 255 { } 256 }; 257 MODULE_DEVICE_TABLE(i2c, eeti_ts_id); 258 259 static struct i2c_driver eeti_ts_driver = { 260 .driver = { 261 .name = "eeti_ts", 262 }, 263 .probe = eeti_ts_probe, 264 .remove = __devexit_p(eeti_ts_remove), 265 .suspend = eeti_ts_suspend, 266 .resume = eeti_ts_resume, 267 .id_table = eeti_ts_id, 268 }; 269 270 static int __init eeti_ts_init(void) 271 { 272 return i2c_add_driver(&eeti_ts_driver); 273 } 274 275 static void __exit eeti_ts_exit(void) 276 { 277 i2c_del_driver(&eeti_ts_driver); 278 } 279 280 MODULE_DESCRIPTION("EETI Touchscreen driver"); 281 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); 282 MODULE_LICENSE("GPL"); 283 284 module_init(eeti_ts_init); 285 module_exit(eeti_ts_exit); 286 287