drivers/media/video/cx231xx/cx231xx-input.c

   1 /*
   2   handle cx231xx IR remotes via linux kernel input layer.
   3
   4   Copyright (C) 2008 <srinivasa.deevi at conexant dot com>
   5                 Based on em28xx driver
   6
   7                 < This is a place holder for IR now.>
   8
   9   This program is free software; you can redistribute it and/or modify
  10   it under the terms of the GNU General Public License as published by
  11   the Free Software Foundation; either version 2 of the License, or
  12   (at your option) any later version.
  13
  14   This program is distributed in the hope that it will be useful,
  15   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17   GNU General Public License for more details.
  18
  19   You should have received a copy of the GNU General Public License
  20   along with this program; if not, write to the Free Software
  21   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/delay.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/input.h>
  29 #include <linux/usb.h>
  30 #include <linux/slab.h>
  31
  32 #include "cx231xx.h"
  33
  34 static unsigned int ir_debug;
  35 module_param(ir_debug, int, 0644);
  36 MODULE_PARM_DESC(ir_debug, "enable debug messages [IR]");
  37
  38 #define MODULE_NAME "cx231xx"
  39
  40 #define i2cdprintk(fmt, arg...) \
  41         if (ir_debug) { \
  42                 printk(KERN_DEBUG "%s/ir: " fmt, ir->name , ## arg); \
  43         }
  44
  45 #define dprintk(fmt, arg...) \
  46         if (ir_debug) { \
  47                 printk(KERN_DEBUG "%s/ir: " fmt, ir->name , ## arg); \
  48         }
  49
  50 /**********************************************************
  51  Polling structure used by cx231xx IR's
  52  **********************************************************/
  53
  54 struct cx231xx_ir_poll_result {
  55         unsigned int toggle_bit:1;
  56         unsigned int read_count:7;
  57         u8 rc_address;
  58         u8 rc_data[4];
  59 };
  60
  61 struct cx231xx_IR {
  62         struct cx231xx *dev;
  63         struct input_dev *input;
  64         struct ir_input_state ir;
  65         char name[32];
  66         char phys[32];
  67
  68         /* poll external decoder */
  69         int polling;
  70         struct work_struct work;
  71         struct timer_list timer;
  72         unsigned int last_toggle:1;
  73         unsigned int last_readcount;
  74         unsigned int repeat_interval;
  75
  76         int (*get_key) (struct cx231xx_IR *, struct cx231xx_ir_poll_result *);
  77 };
  78
  79 /**********************************************************
  80  Polling code for cx231xx
  81  **********************************************************/
  82
  83 static void cx231xx_ir_handle_key(struct cx231xx_IR *ir)
  84 {
  85         int result;
  86         int do_sendkey = 0;
  87         struct cx231xx_ir_poll_result poll_result;
  88
  89         /* read the registers containing the IR status */
  90         result = ir->get_key(ir, &poll_result);
  91         if (result < 0) {
  92                 dprintk("ir->get_key() failed %d\n", result);
  93                 return;
  94         }
  95
  96         dprintk("ir->get_key result tb=%02x rc=%02x lr=%02x data=%02x\n",
  97                 poll_result.toggle_bit, poll_result.read_count,
  98                 ir->last_readcount, poll_result.rc_data[0]);
  99
 100         if (ir->dev->chip_id == CHIP_ID_EM2874) {
 101                 /* The em2874 clears the readcount field every time the
 102                    register is read.  The em2860/2880 datasheet says that it
 103                    is supposed to clear the readcount, but it doesn't.  So with
 104                    the em2874, we are looking for a non-zero read count as
 105                    opposed to a readcount that is incrementing */
 106                 ir->last_readcount = 0;
 107         }
 108
 109         if (poll_result.read_count == 0) {
 110                 /* The button has not been pressed since the last read */
 111         } else if (ir->last_toggle != poll_result.toggle_bit) {
 112                 /* A button has been pressed */
 113                 dprintk("button has been pressed\n");
 114                 ir->last_toggle = poll_result.toggle_bit;
 115                 ir->repeat_interval = 0;
 116                 do_sendkey = 1;
 117         } else if (poll_result.toggle_bit == ir->last_toggle &&
 118                    poll_result.read_count > 0 &&
 119                    poll_result.read_count != ir->last_readcount) {
 120                 /* The button is still being held down */
 121                 dprintk("button being held down\n");
 122
 123                 /* Debouncer for first keypress */
 124                 if (ir->repeat_interval++ > 9) {
 125                         /* Start repeating after 1 second */
 126                         do_sendkey = 1;
 127                 }
 128         }
 129
 130         if (do_sendkey) {
 131                 dprintk("sending keypress\n");
 132                 ir_input_keydown(ir->input, &ir->ir, poll_result.rc_data[0]);
 133                 ir_input_nokey(ir->input, &ir->ir);
 134         }
 135
 136         ir->last_readcount = poll_result.read_count;
 137         return;
 138 }
 139
 140 static void ir_timer(unsigned long data)
 141 {
 142         struct cx231xx_IR *ir = (struct cx231xx_IR *)data;
 143
 144         schedule_work(&ir->work);
 145 }
 146
 147 static void cx231xx_ir_work(struct work_struct *work)
 148 {
 149         struct cx231xx_IR *ir = container_of(work, struct cx231xx_IR, work);
 150
 151         cx231xx_ir_handle_key(ir);
 152         mod_timer(&ir->timer, jiffies + msecs_to_jiffies(ir->polling));
 153 }
 154
 155 void cx231xx_ir_start(struct cx231xx_IR *ir)
 156 {
 157         setup_timer(&ir->timer, ir_timer, (unsigned long)ir);
 158         INIT_WORK(&ir->work, cx231xx_ir_work);
 159         schedule_work(&ir->work);
 160 }
 161
 162 static void cx231xx_ir_stop(struct cx231xx_IR *ir)
 163 {
 164         del_timer_sync(&ir->timer);
 165         flush_scheduled_work();
 166 }
 167
 168 int cx231xx_ir_init(struct cx231xx *dev)
 169 {
 170         struct cx231xx_IR *ir;
 171         struct input_dev *input_dev;
 172         u8 ir_config;
 173         int err = -ENOMEM;
 174
 175         if (dev->board.ir_codes == NULL) {
 176                 /* No remote control support */
 177                 return 0;
 178         }
 179
 180         ir = kzalloc(sizeof(*ir), GFP_KERNEL);
 181         input_dev = input_allocate_device();
 182         if (!ir || !input_dev)
 183                 goto err_out_free;
 184
 185         ir->input = input_dev;
 186
 187         /* Setup the proper handler based on the chip */
 188         switch (dev->chip_id) {
 189         default:
 190                 printk("Unrecognized cx231xx chip id: IR not supported\n");
 191                 goto err_out_free;
 192         }
 193
 194         /* This is how often we ask the chip for IR information */
 195         ir->polling = 100;      /* ms */
 196
 197         /* init input device */
 198         snprintf(ir->name, sizeof(ir->name), "cx231xx IR (%s)", dev->name);
 199
 200         usb_make_path(dev->udev, ir->phys, sizeof(ir->phys));
 201         strlcat(ir->phys, "/input0", sizeof(ir->phys));
 202
 203         err = ir_input_init(input_dev, &ir->ir, IR_TYPE_OTHER);
 204         if (err < 0)
 205                 goto err_out_free;
 206
 207         input_dev->name = ir->name;
 208         input_dev->phys = ir->phys;
 209         input_dev->id.bustype = BUS_USB;
 210         input_dev->id.version = 1;
 211         input_dev->id.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
 212         input_dev->id.product = le16_to_cpu(dev->udev->descriptor.idProduct);
 213
 214         input_dev->dev.parent = &dev->udev->dev;
 215         /* record handles to ourself */
 216         ir->dev = dev;
 217         dev->ir = ir;
 218
 219         cx231xx_ir_start(ir);
 220
 221         /* all done */
 222         err = ir_input_register(ir->input, dev->board.ir_codes,
 223                                 NULL, MODULE_NAME);
 224         if (err)
 225                 goto err_out_stop;
 226
 227         return 0;
 228 err_out_stop:
 229         cx231xx_ir_stop(ir);
 230         dev->ir = NULL;
 231 err_out_free:
 232         kfree(ir);
 233         return err;
 234 }
 235
 236 int cx231xx_ir_fini(struct cx231xx *dev)
 237 {
 238         struct cx231xx_IR *ir = dev->ir;
 239
 240         /* skip detach on non attached boards */
 241         if (!ir)
 242                 return 0;
 243
 244         cx231xx_ir_stop(ir);
 245         ir_input_unregister(ir->input);
 246         kfree(ir);
 247
 248         /* done */
 249         dev->ir = NULL;
 250         return 0;
 251 }