drivers/media/video/tuner-3036.c

   1 /*
   2  * Driver for Philips SAB3036 "CITAC" tuner control chip.
   3  *
   4  * Author: Phil Blundell <philb@gnu.org>
   5  *
   6  * The SAB3036 is just about different enough from the chips that
   7  * tuner.c copes with to make it not worth the effort to crowbar
   8  * the support into that file.  So instead we have a separate driver.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * as published by the Free Software Foundation; either version
  13  * 2 of the License, or (at your option) any later version.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/sched.h>
  19 #include <linux/string.h>
  20 #include <linux/timer.h>
  21 #include <linux/delay.h>
  22 #include <linux/errno.h>
  23 #include <linux/slab.h>
  24 #include <linux/init.h>
  25
  26 #include <linux/i2c.h>
  27 #include <linux/videodev.h>
  28
  29 #include <media/tuner.h>
  30
  31 static int debug;       /* insmod parameter */
  32 static int this_adap;
  33
  34 static struct i2c_client client_template;
  35
  36 /* Addresses to scan */
  37 static unsigned short normal_i2c[] = { 0x60, 0x61, I2C_CLIENT_END };
  38 static unsigned short ignore = I2C_CLIENT_END;
  39
  40 static struct i2c_client_address_data addr_data = {
  41         .normal_i2c     = normal_i2c,
  42         .probe          = &ignore,
  43         .ignore         = &ignore,
  44 };
  45
  46 /* ---------------------------------------------------------------------- */
  47
  48 static unsigned char
  49 tuner_getstatus (struct i2c_client *c)
  50 {
  51         unsigned char byte;
  52         if (i2c_master_recv(c, &byte, 1) != 1)
  53                 printk(KERN_ERR "tuner-3036: I/O error.\n");
  54         return byte;
  55 }
  56
  57 #define TUNER_FL        0x80
  58
  59 static int
  60 tuner_islocked (struct i2c_client *c)
  61 {
  62         return (tuner_getstatus(c) & TUNER_FL);
  63 }
  64
  65 /* ---------------------------------------------------------------------- */
  66
  67 static void
  68 set_tv_freq(struct i2c_client *c, int freq)
  69 {
  70         u16 div = ((freq * 20) / 16);
  71         unsigned long give_up = jiffies + HZ;
  72         unsigned char buffer[2];
  73
  74         if (debug)
  75                 printk(KERN_DEBUG "tuner: setting frequency %dMHz, divisor %x\n", freq / 16, div);
  76
  77         /* Select high tuning current */
  78         buffer[0] = 0x29;
  79         buffer[1] = 0x3e;
  80
  81         if (i2c_master_send(c, buffer, 2) != 2)
  82                 printk("tuner: i2c i/o error 1\n");
  83
  84         buffer[0] = 0x80 | ((div>>8) & 0x7f);
  85         buffer[1] = div & 0xff;
  86
  87         if (i2c_master_send(c, buffer, 2) != 2)
  88                 printk("tuner: i2c i/o error 2\n");
  89
  90         while (!tuner_islocked(c) && time_before(jiffies, give_up))
  91                 schedule();
  92
  93         if (!tuner_islocked(c))
  94                 printk(KERN_WARNING "tuner: failed to achieve PLL lock\n");
  95
  96         /* Select low tuning current and engage AFC */
  97         buffer[0] = 0x29;
  98         buffer[1] = 0xb2;
  99
 100         if (i2c_master_send(c, buffer, 2) != 2)
 101                 printk("tuner: i2c i/o error 3\n");
 102
 103         if (debug)
 104                 printk(KERN_DEBUG "tuner: status %02x\n", tuner_getstatus(c));
 105 }
 106
 107 /* ---------------------------------------------------------------------- */
 108
 109 static int
 110 tuner_attach(struct i2c_adapter *adap, int addr, int kind)
 111 {
 112         static unsigned char buffer[] = { 0x29, 0x32, 0x2a, 0, 0x2b, 0 };
 113
 114         struct i2c_client *client;
 115
 116         if (this_adap > 0)
 117                 return -1;
 118         this_adap++;
 119
 120         client_template.adapter = adap;
 121         client_template.addr = addr;
 122
 123         client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
 124         if (client == NULL)
 125                 return -ENOMEM;
 126         memcpy(client, &client_template, sizeof(struct i2c_client));
 127
 128         printk("tuner: SAB3036 found, status %02x\n", tuner_getstatus(client));
 129
 130         i2c_attach_client(client);
 131
 132         if (i2c_master_send(client, buffer, 2) != 2)
 133                 printk("tuner: i2c i/o error 1\n");
 134         if (i2c_master_send(client, buffer+2, 2) != 2)
 135                 printk("tuner: i2c i/o error 2\n");
 136         if (i2c_master_send(client, buffer+4, 2) != 2)
 137                 printk("tuner: i2c i/o error 3\n");
 138         return 0;
 139 }
 140
 141 static int
 142 tuner_detach(struct i2c_client *c)
 143 {
 144         return 0;
 145 }
 146
 147 static int
 148 tuner_command(struct i2c_client *client, unsigned int cmd, void *arg)
 149 {
 150         int *iarg = (int*)arg;
 151
 152         switch (cmd)
 153         {
 154                 case VIDIOCSFREQ:
 155                         set_tv_freq(client, *iarg);
 156                         break;
 157
 158                 default:
 159                         return -EINVAL;
 160         }
 161         return 0;
 162 }
 163
 164 static int
 165 tuner_probe(struct i2c_adapter *adap)
 166 {
 167         this_adap = 0;
 168         if (adap->id == I2C_HW_B_LP)
 169                 return i2c_probe(adap, &addr_data, tuner_attach);
 170         return 0;
 171 }
 172
 173 /* ----------------------------------------------------------------------- */
 174
 175 static struct i2c_driver
 176 i2c_driver_tuner =
 177 {
 178         .driver = {
 179                 .name   =       "sab3036",
 180         },
 181         .id             =       I2C_DRIVERID_SAB3036,
 182         .attach_adapter =       tuner_probe,
 183         .detach_client  =       tuner_detach,
 184         .command        =       tuner_command
 185 };
 186
 187 static struct i2c_client client_template =
 188 {
 189         .driver         = &i2c_driver_tuner,
 190         .name           = "SAB3036",
 191 };
 192
 193 static int __init
 194 tuner3036_init(void)
 195 {
 196         return i2c_add_driver(&i2c_driver_tuner);
 197 }
 198
 199 static void __exit
 200 tuner3036_exit(void)
 201 {
 202         i2c_del_driver(&i2c_driver_tuner);
 203 }
 204
 205 MODULE_DESCRIPTION("SAB3036 tuner driver");
 206 MODULE_AUTHOR("Philip Blundell <philb@gnu.org>");
 207 MODULE_LICENSE("GPL");
 208
 209 module_param(debug, int, 0);
 210 MODULE_PARM_DESC(debug,"Enable debugging output");
 211
 212 module_init(tuner3036_init);
 213 module_exit(tuner3036_exit);