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 i2cdprintk(fmt, arg...) \
  39         if (ir_debug) { \
  40                 printk(KERN_DEBUG "%s/ir: " fmt, ir->name , ## arg); \
  41         }
  42
  43 #define dprintk(fmt, arg...) \
  44         if (ir_debug) { \
  45                 printk(KERN_DEBUG "%s/ir: " fmt, ir->name , ## arg); \
  46         }
  47
  48 /**********************************************************
  49  Polling structure used by cx231xx IR's
  50  **********************************************************/
  51
  52 struct cx231xx_ir_poll_result {
  53         unsigned int toggle_bit:1;
  54         unsigned int read_count:7;
  55         u8 rc_address;
  56         u8 rc_data[4];
  57 };
  58
  59 struct cx231xx_IR {
  60         struct cx231xx *dev;
  61         struct input_dev *input;
  62         struct ir_input_state ir;
  63         char name[32];
  64         char phys[32];
  65
  66         /* poll external decoder */
  67         int polling;
  68         struct work_struct work;
  69         struct timer_list timer;
  70         unsigned int last_toggle:1;
  71         unsigned int last_readcount;
  72         unsigned int repeat_interval;
  73
  74         int (*get_key) (struct cx231xx_IR *, struct cx231xx_ir_poll_result *);
  75 };
  76
  77 /**********************************************************
  78  Polling code for cx231xx
  79  **********************************************************/
  80
  81 static void cx231xx_ir_handle_key(struct cx231xx_IR *ir)
  82 {
  83         int result;
  84         int do_sendkey = 0;
  85         struct cx231xx_ir_poll_result poll_result;
  86
  87         /* read the registers containing the IR status */
  88         result = ir->get_key(ir, &poll_result);
  89         if (result < 0) {
  90                 dprintk("ir->get_key() failed %d\n", result);
  91                 return;
  92         }
  93
  94         dprintk("ir->get_key result tb=%02x rc=%02x lr=%02x data=%02x\n",
  95                 poll_result.toggle_bit, poll_result.read_count,
  96                 ir->last_readcount, poll_result.rc_data[0]);
  97
  98         if (ir->dev->chip_id == CHIP_ID_EM2874) {
  99                 /* The em2874 clears the readcount field every time the
 100                    register is read.  The em2860/2880 datasheet says that it
 101                    is supposed to clear the readcount, but it doesn't.  So with
 102                    the em2874, we are looking for a non-zero read count as
 103                    opposed to a readcount that is incrementing */
 104                 ir->last_readcount = 0;
 105         }
 106
 107         if (poll_result.read_count == 0) {
 108                 /* The button has not been pressed since the last read */
 109         } else if (ir->last_toggle != poll_result.toggle_bit) {
 110                 /* A button has been pressed */
 111                 dprintk("button has been pressed\n");
 112                 ir->last_toggle = poll_result.toggle_bit;
 113                 ir->repeat_interval = 0;
 114                 do_sendkey = 1;
 115         } else if (poll_result.toggle_bit == ir->last_toggle &&
 116                    poll_result.read_count > 0 &&
 117                    poll_result.read_count != ir->last_readcount) {
 118                 /* The button is still being held down */
 119                 dprintk("button being held down\n");
 120
 121                 /* Debouncer for first keypress */
 122                 if (ir->repeat_interval++ > 9) {
 123                         /* Start repeating after 1 second */
 124                         do_sendkey = 1;
 125                 }
 126         }
 127
 128         if (do_sendkey) {
 129                 dprintk("sending keypress\n");
 130                 ir_input_keydown(ir->input, &ir->ir, poll_result.rc_data[0]);
 131                 ir_input_nokey(ir->input, &ir->ir);
 132         }
 133
 134         ir->last_readcount = poll_result.read_count;
 135         return;
 136 }
 137
 138 static void ir_timer(unsigned long data)
 139 {
 140         struct cx231xx_IR *ir = (struct cx231xx_IR *)data;
 141
 142         schedule_work(&ir->work);
 143 }
 144
 145 static void cx231xx_ir_work(struct work_struct *work)
 146 {
 147         struct cx231xx_IR *ir = container_of(work, struct cx231xx_IR, work);
 148
 149         cx231xx_ir_handle_key(ir);
 150         mod_timer(&ir->timer, jiffies + msecs_to_jiffies(ir->polling));
 151 }
 152
 153 void cx231xx_ir_start(struct cx231xx_IR *ir)
 154 {
 155         setup_timer(&ir->timer, ir_timer, (unsigned long)ir);
 156         INIT_WORK(&ir->work, cx231xx_ir_work);
 157         schedule_work(&ir->work);
 158 }
 159
 160 static void cx231xx_ir_stop(struct cx231xx_IR *ir)
 161 {
 162         del_timer_sync(&ir->timer);
 163         flush_scheduled_work();
 164 }
 165
 166 int cx231xx_ir_init(struct cx231xx *dev)
 167 {
 168         struct cx231xx_IR *ir;
 169         struct input_dev *input_dev;
 170         u8 ir_config;
 171         int err = -ENOMEM;
 172
 173         if (dev->board.ir_codes == NULL) {
 174                 /* No remote control support */
 175                 return 0;
 176         }
 177
 178         ir = kzalloc(sizeof(*ir), GFP_KERNEL);
 179         input_dev = input_allocate_device();
 180         if (!ir || !input_dev)
 181                 goto err_out_free;
 182
 183         ir->input = input_dev;
 184
 185         /* Setup the proper handler based on the chip */
 186         switch (dev->chip_id) {
 187         default:
 188                 printk("Unrecognized cx231xx chip id: IR not supported\n");
 189                 goto err_out_free;
 190         }
 191
 192         /* This is how often we ask the chip for IR information */
 193         ir->polling = 100;      /* ms */
 194
 195         /* init input device */
 196         snprintf(ir->name, sizeof(ir->name), "cx231xx IR (%s)", dev->name);
 197
 198         usb_make_path(dev->udev, ir->phys, sizeof(ir->phys));
 199         strlcat(ir->phys, "/input0", sizeof(ir->phys));
 200
 201         err = ir_input_init(input_dev, &ir->ir, IR_TYPE_OTHER);
 202         if (err < 0)
 203                 goto err_out_free;
 204
 205         input_dev->name = ir->name;
 206         input_dev->phys = ir->phys;
 207         input_dev->id.bustype = BUS_USB;
 208         input_dev->id.version = 1;
 209         input_dev->id.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
 210         input_dev->id.product = le16_to_cpu(dev->udev->descriptor.idProduct);
 211
 212         input_dev->dev.parent = &dev->udev->dev;
 213         /* record handles to ourself */
 214         ir->dev = dev;
 215         dev->ir = ir;
 216
 217         cx231xx_ir_start(ir);
 218
 219         /* all done */
 220         err = ir_input_register(ir->input, dev->board.ir_codes, NULL);
 221         if (err)
 222                 goto err_out_stop;
 223
 224         return 0;
 225 err_out_stop:
 226         cx231xx_ir_stop(ir);
 227         dev->ir = NULL;
 228 err_out_free:
 229         kfree(ir);
 230         return err;
 231 }
 232
 233 int cx231xx_ir_fini(struct cx231xx *dev)
 234 {
 235         struct cx231xx_IR *ir = dev->ir;
 236
 237         /* skip detach on non attached boards */
 238         if (!ir)
 239                 return 0;
 240
 241         cx231xx_ir_stop(ir);
 242         ir_input_unregister(ir->input);
 243         kfree(ir);
 244
 245         /* done */
 246         dev->ir = NULL;
 247         return 0;
 248 }