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/pm.h>
  27 #include <linux/slab.h>
  28 #include <asm/io.h>
  29 #include <linux/i2c.h>
  30 #include <linux/timer.h>
  31
  32 #define EVENT_PENDOWN 1
  33 #define EVENT_REPEAT  2
  34 #define EVENT_PENUP   3
  35
  36 struct migor_ts_priv {
  37         struct i2c_client *client;
  38         struct input_dev *input;
  39         struct delayed_work work;
  40         int irq;
  41 };
  42
  43 static const u_int8_t migor_ts_ena_seq[17] = { 0x33, 0x22, 0x11,
  44                                                0x01, 0x06, 0x07, };
  45 static const u_int8_t migor_ts_dis_seq[17] = { };
  46
  47 static void migor_ts_poscheck(struct work_struct *work)
  48 {
  49         struct migor_ts_priv *priv = container_of(work,
  50                                                   struct migor_ts_priv,
  51                                                   work.work);
  52         unsigned short xpos, ypos;
  53         unsigned char event;
  54         u_int8_t buf[16];
  55
  56         memset(buf, 0, sizeof(buf));
  57
  58         /* Set Index 0 */
  59         buf[0] = 0;
  60         if (i2c_master_send(priv->client, buf, 1) != 1) {
  61                 dev_err(&priv->client->dev, "Unable to write i2c index\n");
  62                 goto out;
  63         }
  64
  65         /* Now do Page Read */
  66         if (i2c_master_recv(priv->client, buf, sizeof(buf)) != sizeof(buf)) {
  67                 dev_err(&priv->client->dev, "Unable to read i2c page\n");
  68                 goto out;
  69         }
  70
  71         ypos = ((buf[9] & 0x03) << 8 | buf[8]);
  72         xpos = ((buf[11] & 0x03) << 8 | buf[10]);
  73         event = buf[12];
  74
  75         if (event == EVENT_PENDOWN || event == EVENT_REPEAT) {
  76                 input_report_key(priv->input, BTN_TOUCH, 1);
  77                 input_report_abs(priv->input, ABS_X, ypos); /*X-Y swap*/
  78                 input_report_abs(priv->input, ABS_Y, xpos);
  79                 input_sync(priv->input);
  80         } else if (event == EVENT_PENUP) {
  81                 input_report_key(priv->input, BTN_TOUCH, 0);
  82                 input_sync(priv->input);
  83         }
  84  out:
  85         enable_irq(priv->irq);
  86 }
  87
  88 static irqreturn_t migor_ts_isr(int irq, void *dev_id)
  89 {
  90         struct migor_ts_priv *priv = dev_id;
  91
  92         /* the touch screen controller chip is hooked up to the cpu
  93          * using i2c and a single interrupt line. the interrupt line
  94          * is pulled low whenever someone taps the screen. to deassert
  95          * the interrupt line we need to acknowledge the interrupt by
  96          * communicating with the controller over the slow i2c bus.
  97          *
  98          * we can't acknowledge from interrupt context since the i2c
  99          * bus controller may sleep, so we just disable the interrupt
 100          * here and handle the acknowledge using delayed work.
 101          */
 102
 103         disable_irq_nosync(irq);
 104         schedule_delayed_work(&priv->work, HZ / 20);
 105
 106         return IRQ_HANDLED;
 107 }
 108
 109
 110 static int migor_ts_open(struct input_dev *dev)
 111 {
 112         struct migor_ts_priv *priv = input_get_drvdata(dev);
 113         struct i2c_client *client = priv->client;
 114         int count;
 115
 116         /* enable controller */
 117         count = i2c_master_send(client, migor_ts_ena_seq,
 118                                 sizeof(migor_ts_ena_seq));
 119         if (count != sizeof(migor_ts_ena_seq)) {
 120                 dev_err(&client->dev, "Unable to enable touchscreen.\n");
 121                 return -ENXIO;
 122         }
 123
 124         return 0;
 125 }
 126
 127 static void migor_ts_close(struct input_dev *dev)
 128 {
 129         struct migor_ts_priv *priv = input_get_drvdata(dev);
 130         struct i2c_client *client = priv->client;
 131
 132         disable_irq(priv->irq);
 133
 134         /* cancel pending work and wait for migor_ts_poscheck() to finish */
 135         if (cancel_delayed_work_sync(&priv->work)) {
 136                 /*
 137                  * if migor_ts_poscheck was canceled we need to enable IRQ
 138                  * here to balance disable done in migor_ts_isr.
 139                  */
 140                 enable_irq(priv->irq);
 141         }
 142
 143         /* disable controller */
 144         i2c_master_send(client, migor_ts_dis_seq, sizeof(migor_ts_dis_seq));
 145
 146         enable_irq(priv->irq);
 147 }
 148
 149 static int migor_ts_probe(struct i2c_client *client,
 150                           const struct i2c_device_id *idp)
 151 {
 152         struct migor_ts_priv *priv;
 153         struct input_dev *input;
 154         int error;
 155
 156         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 157         if (!priv) {
 158                 dev_err(&client->dev, "failed to allocate driver data\n");
 159                 error = -ENOMEM;
 160                 goto err0;
 161         }
 162
 163         dev_set_drvdata(&client->dev, priv);
 164
 165         input = input_allocate_device();
 166         if (!input) {
 167                 dev_err(&client->dev, "Failed to allocate input device.\n");
 168                 error = -ENOMEM;
 169                 goto err1;
 170         }
 171
 172         input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 173         input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
 174
 175         input_set_abs_params(input, ABS_X, 95, 955, 0, 0);
 176         input_set_abs_params(input, ABS_Y, 85, 935, 0, 0);
 177
 178         input->name = client->name;
 179         input->id.bustype = BUS_I2C;
 180         input->dev.parent = &client->dev;
 181
 182         input->open = migor_ts_open;
 183         input->close = migor_ts_close;
 184
 185         input_set_drvdata(input, priv);
 186
 187         priv->client = client;
 188         priv->input = input;
 189         INIT_DELAYED_WORK(&priv->work, migor_ts_poscheck);
 190         priv->irq = client->irq;
 191
 192         error = input_register_device(input);
 193         if (error)
 194                 goto err1;
 195
 196         error = request_irq(priv->irq, migor_ts_isr, IRQF_TRIGGER_LOW,
 197                             client->name, priv);
 198         if (error) {
 199                 dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
 200                 goto err2;
 201         }
 202
 203         device_init_wakeup(&client->dev, 1);
 204         return 0;
 205
 206  err2:
 207         input_unregister_device(input);
 208         input = NULL; /* so we dont try to free it below */
 209  err1:
 210         input_free_device(input);
 211         kfree(priv);
 212  err0:
 213         dev_set_drvdata(&client->dev, NULL);
 214         return error;
 215 }
 216
 217 static int migor_ts_remove(struct i2c_client *client)
 218 {
 219         struct migor_ts_priv *priv = dev_get_drvdata(&client->dev);
 220
 221         free_irq(priv->irq, priv);
 222         input_unregister_device(priv->input);
 223         kfree(priv);
 224
 225         dev_set_drvdata(&client->dev, NULL);
 226
 227         return 0;
 228 }
 229
 230 static int migor_ts_suspend(struct device *dev)
 231 {
 232         struct i2c_client *client = to_i2c_client(dev);
 233         struct migor_ts_priv *priv = dev_get_drvdata(&client->dev);
 234
 235         if (device_may_wakeup(&client->dev))
 236                 enable_irq_wake(priv->irq);
 237
 238         return 0;
 239 }
 240
 241 static int migor_ts_resume(struct device *dev)
 242 {
 243         struct i2c_client *client = to_i2c_client(dev);
 244         struct migor_ts_priv *priv = dev_get_drvdata(&client->dev);
 245
 246         if (device_may_wakeup(&client->dev))
 247                 disable_irq_wake(priv->irq);
 248
 249         return 0;
 250 }
 251
 252 static SIMPLE_DEV_PM_OPS(migor_ts_pm, migor_ts_suspend, migor_ts_resume);
 253
 254 static const struct i2c_device_id migor_ts_id[] = {
 255         { "migor_ts", 0 },
 256         { }
 257 };
 258 MODULE_DEVICE_TABLE(i2c, migor_ts);
 259
 260 static struct i2c_driver migor_ts_driver = {
 261         .driver = {
 262                 .name = "migor_ts",
 263                 .pm = &migor_ts_pm,
 264         },
 265         .probe = migor_ts_probe,
 266         .remove = migor_ts_remove,
 267         .id_table = migor_ts_id,
 268 };
 269
 270 static int __init migor_ts_init(void)
 271 {
 272         return i2c_add_driver(&migor_ts_driver);
 273 }
 274
 275 static void __exit migor_ts_exit(void)
 276 {
 277         i2c_del_driver(&migor_ts_driver);
 278 }
 279
 280 MODULE_DESCRIPTION("MigoR Touchscreen driver");
 281 MODULE_AUTHOR("Magnus Damm <damm@opensource.se>");
 282 MODULE_LICENSE("GPL");
 283
 284 module_init(migor_ts_init);
 285 module_exit(migor_ts_exit);