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 <linux/slab.h>
  27 #include <asm/io.h>
  28 #include <linux/i2c.h>
  29 #include <linux/timer.h>
  30
  31 #define EVENT_PENDOWN 1
  32 #define EVENT_REPEAT  2
  33 #define EVENT_PENUP   3
  34
  35 struct migor_ts_priv {
  36         struct i2c_client *client;
  37         struct input_dev *input;
  38         struct delayed_work work;
  39         int irq;
  40 };
  41
  42 static const u_int8_t migor_ts_ena_seq[17] = { 0x33, 0x22, 0x11,
  43                                                0x01, 0x06, 0x07, };
  44 static const u_int8_t migor_ts_dis_seq[17] = { };
  45
  46 static void migor_ts_poscheck(struct work_struct *work)
  47 {
  48         struct migor_ts_priv *priv = container_of(work,
  49                                                   struct migor_ts_priv,
  50                                                   work.work);
  51         unsigned short xpos, ypos;
  52         unsigned char event;
  53         u_int8_t buf[16];
  54
  55         memset(buf, 0, sizeof(buf));
  56
  57         /* Set Index 0 */
  58         buf[0] = 0;
  59         if (i2c_master_send(priv->client, buf, 1) != 1) {
  60                 dev_err(&priv->client->dev, "Unable to write i2c index\n");
  61                 goto out;
  62         }
  63
  64         /* Now do Page Read */
  65         if (i2c_master_recv(priv->client, buf, sizeof(buf)) != sizeof(buf)) {
  66                 dev_err(&priv->client->dev, "Unable to read i2c page\n");
  67                 goto out;
  68         }
  69
  70         ypos = ((buf[9] & 0x03) << 8 | buf[8]);
  71         xpos = ((buf[11] & 0x03) << 8 | buf[10]);
  72         event = buf[12];
  73
  74         if (event == EVENT_PENDOWN || event == EVENT_REPEAT) {
  75                 input_report_key(priv->input, BTN_TOUCH, 1);
  76                 input_report_abs(priv->input, ABS_X, ypos); /*X-Y swap*/
  77                 input_report_abs(priv->input, ABS_Y, xpos);
  78                 input_sync(priv->input);
  79         } else if (event == EVENT_PENUP) {
  80                 input_report_key(priv->input, BTN_TOUCH, 0);
  81                 input_sync(priv->input);
  82         }
  83  out:
  84         enable_irq(priv->irq);
  85 }
  86
  87 static irqreturn_t migor_ts_isr(int irq, void *dev_id)
  88 {
  89         struct migor_ts_priv *priv = dev_id;
  90
  91         /* the touch screen controller chip is hooked up to the cpu
  92          * using i2c and a single interrupt line. the interrupt line
  93          * is pulled low whenever someone taps the screen. to deassert
  94          * the interrupt line we need to acknowledge the interrupt by
  95          * communicating with the controller over the slow i2c bus.
  96          *
  97          * we can't acknowledge from interrupt context since the i2c
  98          * bus controller may sleep, so we just disable the interrupt
  99          * here and handle the acknowledge using delayed work.
 100          */
 101
 102         disable_irq_nosync(irq);
 103         schedule_delayed_work(&priv->work, HZ / 20);
 104
 105         return IRQ_HANDLED;
 106 }
 107
 108
 109 static int migor_ts_open(struct input_dev *dev)
 110 {
 111         struct migor_ts_priv *priv = input_get_drvdata(dev);
 112         struct i2c_client *client = priv->client;
 113         int count;
 114
 115         /* enable controller */
 116         count = i2c_master_send(client, migor_ts_ena_seq,
 117                                 sizeof(migor_ts_ena_seq));
 118         if (count != sizeof(migor_ts_ena_seq)) {
 119                 dev_err(&client->dev, "Unable to enable touchscreen.\n");
 120                 return -ENXIO;
 121         }
 122
 123         return 0;
 124 }
 125
 126 static void migor_ts_close(struct input_dev *dev)
 127 {
 128         struct migor_ts_priv *priv = input_get_drvdata(dev);
 129         struct i2c_client *client = priv->client;
 130
 131         disable_irq(priv->irq);
 132
 133         /* cancel pending work and wait for migor_ts_poscheck() to finish */
 134         if (cancel_delayed_work_sync(&priv->work)) {
 135                 /*
 136                  * if migor_ts_poscheck was canceled we need to enable IRQ
 137                  * here to balance disable done in migor_ts_isr.
 138                  */
 139                 enable_irq(priv->irq);
 140         }
 141
 142         /* disable controller */
 143         i2c_master_send(client, migor_ts_dis_seq, sizeof(migor_ts_dis_seq));
 144
 145         enable_irq(priv->irq);
 146 }
 147
 148 static int migor_ts_probe(struct i2c_client *client,
 149                           const struct i2c_device_id *idp)
 150 {
 151         struct migor_ts_priv *priv;
 152         struct input_dev *input;
 153         int error;
 154
 155         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 156         if (!priv) {
 157                 dev_err(&client->dev, "failed to allocate driver data\n");
 158                 error = -ENOMEM;
 159                 goto err0;
 160         }
 161
 162         dev_set_drvdata(&client->dev, priv);
 163
 164         input = input_allocate_device();
 165         if (!input) {
 166                 dev_err(&client->dev, "Failed to allocate input device.\n");
 167                 error = -ENOMEM;
 168                 goto err1;
 169         }
 170
 171         input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 172         input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 173
 174         input_set_abs_params(input, ABS_X, 95, 955, 0, 0);
 175         input_set_abs_params(input, ABS_Y, 85, 935, 0, 0);
 176
 177         input->name = client->name;
 178         input->id.bustype = BUS_I2C;
 179         input->dev.parent = &client->dev;
 180
 181         input->open = migor_ts_open;
 182         input->close = migor_ts_close;
 183
 184         input_set_drvdata(input, priv);
 185
 186         priv->client = client;
 187         priv->input = input;
 188         INIT_DELAYED_WORK(&priv->work, migor_ts_poscheck);
 189         priv->irq = client->irq;
 190
 191         error = input_register_device(input);
 192         if (error)
 193                 goto err1;
 194
 195         error = request_irq(priv->irq, migor_ts_isr, IRQF_TRIGGER_LOW,
 196                             client->name, priv);
 197         if (error) {
 198                 dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
 199                 goto err2;
 200         }
 201
 202         device_init_wakeup(&client->dev, 1);
 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         kfree(priv);
 211  err0:
 212         dev_set_drvdata(&client->dev, NULL);
 213         return error;
 214 }
 215
 216 static int migor_ts_remove(struct i2c_client *client)
 217 {
 218         struct migor_ts_priv *priv = dev_get_drvdata(&client->dev);
 219
 220         free_irq(priv->irq, priv);
 221         input_unregister_device(priv->input);
 222         kfree(priv);
 223
 224         dev_set_drvdata(&client->dev, NULL);
 225
 226         return 0;
 227 }
 228
 229 static int migor_ts_suspend(struct i2c_client *client, pm_message_t mesg)
 230 {
 231         struct migor_ts_priv *priv = dev_get_drvdata(&client->dev);
 232
 233         if (device_may_wakeup(&client->dev))
 234                 enable_irq_wake(priv->irq);
 235
 236         return 0;
 237 }
 238
 239 static int migor_ts_resume(struct i2c_client *client)
 240 {
 241         struct migor_ts_priv *priv = dev_get_drvdata(&client->dev);
 242
 243         if (device_may_wakeup(&client->dev))
 244                 disable_irq_wake(priv->irq);
 245
 246         return 0;
 247 }
 248
 249 static const struct i2c_device_id migor_ts_id[] = {
 250         { "migor_ts", 0 },
 251         { }
 252 };
 253 MODULE_DEVICE_TABLE(i2c, migor_ts);
 254
 255 static struct i2c_driver migor_ts_driver = {
 256         .driver = {
 257                 .name = "migor_ts",
 258         },
 259         .probe = migor_ts_probe,
 260         .remove = migor_ts_remove,
 261         .suspend = migor_ts_suspend,
 262         .resume = migor_ts_resume,
 263         .id_table = migor_ts_id,
 264 };
 265
 266 static int __init migor_ts_init(void)
 267 {
 268         return i2c_add_driver(&migor_ts_driver);
 269 }
 270
 271 static void __exit migor_ts_exit(void)
 272 {
 273         i2c_del_driver(&migor_ts_driver);
 274 }
 275
 276 MODULE_DESCRIPTION("MigoR Touchscreen driver");
 277 MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
 278 MODULE_LICENSE("GPL");
 279
 280 module_init(migor_ts_init);
 281 module_exit(migor_ts_exit);