drivers/input/touchscreen/migor_ts.c

   1 /*
   2  * Touch Screen driver for Renesas MIGO-R Platform
   3  *
   4  * Copyright (c) 2008 Magnus Damm
   5  * Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com>,
   6  *  Kenati Technologies Pvt Ltd.
   7  *
   8  * This file is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU  General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2 of the License, or (at your option) any later version.
  12  *
  13  * This file is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *  General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22 #include <linux/module.h>
  23 #include <linux/kernel.h>
  24 #include <linux/input.h>
  25 #include <linux/interrupt.h>
  26 #include <asm/io.h>
  27 #include <linux/i2c.h>
  28 #include <linux/timer.h>
  29
  30 #define EVENT_PENDOWN 1
  31 #define EVENT_REPEAT  2
  32 #define EVENT_PENUP   3
  33
  34 struct migor_ts_priv {
  35         struct i2c_client *client;
  36         struct input_dev *input;
  37         struct delayed_work work;
  38         int irq;
  39 };
  40
  41 static const u_int8_t migor_ts_ena_seq[17] = { 0x33, 0x22, 0x11,
  42                                                0x01, 0x06, 0x07, };
  43 static const u_int8_t migor_ts_dis_seq[17] = { };
  44
  45 static void migor_ts_poscheck(struct work_struct *work)
  46 {
  47         struct migor_ts_priv *priv = container_of(work,
  48                                                   struct migor_ts_priv,
  49                                                   work.work);
  50         unsigned short xpos, ypos;
  51         unsigned char event;
  52         u_int8_t buf[16];
  53
  54         memset(buf, 0, sizeof(buf));
  55
  56         /* Set Index 0 */
  57         buf[0] = 0;
  58         if (i2c_master_send(priv->client, buf, 1) != 1) {
  59                 dev_err(&priv->client->dev, "Unable to write i2c index\n");
  60                 goto out;
  61         }
  62
  63         /* Now do Page Read */
  64         if (i2c_master_recv(priv->client, buf, sizeof(buf)) != sizeof(buf)) {
  65                 dev_err(&priv->client->dev, "Unable to read i2c page\n");
  66                 goto out;
  67         }
  68
  69         ypos = ((buf[9] & 0x03) << 8 | buf[8]);
  70         xpos = ((buf[11] & 0x03) << 8 | buf[10]);
  71         event = buf[12];
  72
  73         if (event == EVENT_PENDOWN || event == EVENT_REPEAT) {
  74                 input_report_key(priv->input, BTN_TOUCH, 1);
  75                 input_report_abs(priv->input, ABS_X, ypos); /*X-Y swap*/
  76                 input_report_abs(priv->input, ABS_Y, xpos);
  77                 input_sync(priv->input);
  78         } else if (event == EVENT_PENUP) {
  79                 input_report_key(priv->input, BTN_TOUCH, 0);
  80                 input_sync(priv->input);
  81         }
  82  out:
  83         enable_irq(priv->irq);
  84 }
  85
  86 static irqreturn_t migor_ts_isr(int irq, void *dev_id)
  87 {
  88         struct migor_ts_priv *priv = dev_id;
  89
  90         /* the touch screen controller chip is hooked up to the cpu
  91          * using i2c and a single interrupt line. the interrupt line
  92          * is pulled low whenever someone taps the screen. to deassert
  93          * the interrupt line we need to acknowledge the interrupt by
  94          * communicating with the controller over the slow i2c bus.
  95          *
  96          * we can't acknowledge from interrupt context since the i2c
  97          * bus controller may sleep, so we just disable the interrupt
  98          * here and handle the acknowledge using delayed work.
  99          */
 100
 101         disable_irq_nosync(irq);
 102         schedule_delayed_work(&priv->work, HZ / 20);
 103
 104         return IRQ_HANDLED;
 105 }
 106
 107
 108 static int migor_ts_open(struct input_dev *dev)
 109 {
 110         struct migor_ts_priv *priv = input_get_drvdata(dev);
 111         struct i2c_client *client = priv->client;
 112         int count;
 113
 114         /* enable controller */
 115         count = i2c_master_send(client, migor_ts_ena_seq,
 116                                 sizeof(migor_ts_ena_seq));
 117         if (count != sizeof(migor_ts_ena_seq)) {
 118                 dev_err(&client->dev, "Unable to enable touchscreen.\n");
 119                 return -ENXIO;
 120         }
 121
 122         return 0;
 123 }
 124
 125 static void migor_ts_close(struct input_dev *dev)
 126 {
 127         struct migor_ts_priv *priv = input_get_drvdata(dev);
 128         struct i2c_client *client = priv->client;
 129
 130         disable_irq(priv->irq);
 131
 132         /* cancel pending work and wait for migor_ts_poscheck() to finish */
 133         if (cancel_delayed_work_sync(&priv->work)) {
 134                 /*
 135                  * if migor_ts_poscheck was canceled we need to enable IRQ
 136                  * here to balance disable done in migor_ts_isr.
 137                  */
 138                 enable_irq(priv->irq);
 139         }
 140
 141         /* disable controller */
 142         i2c_master_send(client, migor_ts_dis_seq, sizeof(migor_ts_dis_seq));
 143
 144         enable_irq(priv->irq);
 145 }
 146
 147 static int migor_ts_probe(struct i2c_client *client,
 148                           const struct i2c_device_id *idp)
 149 {
 150         struct migor_ts_priv *priv;
 151         struct input_dev *input;
 152         int error;
 153
 154         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 155         if (!priv) {
 156                 dev_err(&client->dev, "failed to allocate driver data\n");
 157                 error = -ENOMEM;
 158                 goto err0;
 159         }
 160
 161         dev_set_drvdata(&client->dev, priv);
 162
 163         input = input_allocate_device();
 164         if (!input) {
 165                 dev_err(&client->dev, "Failed to allocate input device.\n");
 166                 error = -ENOMEM;
 167                 goto err1;
 168         }
 169
 170         input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 171         input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 172
 173         input_set_abs_params(input, ABS_X, 95, 955, 0, 0);
 174         input_set_abs_params(input, ABS_Y, 85, 935, 0, 0);
 175
 176         input->name = client->name;
 177         input->id.bustype = BUS_I2C;
 178         input->dev.parent = &client->dev;
 179
 180         input->open = migor_ts_open;
 181         input->close = migor_ts_close;
 182
 183         input_set_drvdata(input, priv);
 184
 185         priv->client = client;
 186         priv->input = input;
 187         INIT_DELAYED_WORK(&priv->work, migor_ts_poscheck);
 188         priv->irq = client->irq;
 189
 190         error = input_register_device(input);
 191         if (error)
 192                 goto err1;
 193
 194         error = request_irq(priv->irq, migor_ts_isr, IRQF_TRIGGER_LOW,
 195                             client->name, priv);
 196         if (error) {
 197                 dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
 198                 goto err2;
 199         }
 200
 201         device_init_wakeup(&client->dev, 1);
 202         return 0;
 203
 204  err2:
 205         input_unregister_device(input);
 206         input = NULL; /* so we dont try to free it below */
 207  err1:
 208         input_free_device(input);
 209         kfree(priv);
 210  err0:
 211         dev_set_drvdata(&client->dev, NULL);
 212         return error;
 213 }
 214
 215 static int migor_ts_remove(struct i2c_client *client)
 216 {
 217         struct migor_ts_priv *priv = dev_get_drvdata(&client->dev);
 218
 219         free_irq(priv->irq, priv);
 220         input_unregister_device(priv->input);
 221         kfree(priv);
 222
 223         dev_set_drvdata(&client->dev, NULL);
 224
 225         return 0;
 226 }
 227
 228 static int migor_ts_suspend(struct i2c_client *client, pm_message_t mesg)
 229 {
 230         struct migor_ts_priv *priv = dev_get_drvdata(&client->dev);
 231
 232         if (device_may_wakeup(&client->dev))
 233                 enable_irq_wake(priv->irq);
 234
 235         return 0;
 236 }
 237
 238 static int migor_ts_resume(struct i2c_client *client)
 239 {
 240         struct migor_ts_priv *priv = dev_get_drvdata(&client->dev);
 241
 242         if (device_may_wakeup(&client->dev))
 243                 disable_irq_wake(priv->irq);
 244
 245         return 0;
 246 }
 247
 248 static const struct i2c_device_id migor_ts_id[] = {
 249         { "migor_ts", 0 },
 250         { }
 251 };
 252 MODULE_DEVICE_TABLE(i2c, migor_ts);
 253
 254 static struct i2c_driver migor_ts_driver = {
 255         .driver = {
 256                 .name = "migor_ts",
 257         },
 258         .probe = migor_ts_probe,
 259         .remove = migor_ts_remove,
 260         .suspend = migor_ts_suspend,
 261         .resume = migor_ts_resume,
 262         .id_table = migor_ts_id,
 263 };
 264
 265 static int __init migor_ts_init(void)
 266 {
 267         return i2c_add_driver(&migor_ts_driver);
 268 }
 269
 270 static void __exit migor_ts_exit(void)
 271 {
 272         i2c_del_driver(&migor_ts_driver);
 273 }
 274
 275 MODULE_DESCRIPTION("MigoR Touchscreen driver");
 276 MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
 277 MODULE_LICENSE("GPL");
 278
 279 module_init(migor_ts_init);
 280 module_exit(migor_ts_exit);