drivers/media/radio/tef6862.c

   1 /*
   2  * tef6862.c Philips TEF6862 Car Radio Enhanced Selectivity Tuner
   3  * Copyright (c) 2009 Intel Corporation
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/init.h>
  21 #include <linux/errno.h>
  22 #include <linux/kernel.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/i2c.h>
  25 #include <linux/slab.h>
  26 #include <media/v4l2-ioctl.h>
  27 #include <media/v4l2-device.h>
  28
  29 #define DRIVER_NAME "tef6862"
  30
  31 #define FREQ_MUL 16000
  32
  33 #define TEF6862_LO_FREQ (875U * FREQ_MUL / 10)
  34 #define TEF6862_HI_FREQ (108U * FREQ_MUL)
  35
  36 /* Write mode sub addresses */
  37 #define WM_SUB_BANDWIDTH        0x0
  38 #define WM_SUB_PLLM             0x1
  39 #define WM_SUB_PLLL             0x2
  40 #define WM_SUB_DAA              0x3
  41 #define WM_SUB_AGC              0x4
  42 #define WM_SUB_BAND             0x5
  43 #define WM_SUB_CONTROL          0x6
  44 #define WM_SUB_LEVEL            0x7
  45 #define WM_SUB_IFCF             0x8
  46 #define WM_SUB_IFCAP            0x9
  47 #define WM_SUB_ACD              0xA
  48 #define WM_SUB_TEST             0xF
  49
  50 /* Different modes of the MSA register */
  51 #define MSA_MODE_BUFFER         0x0
  52 #define MSA_MODE_PRESET         0x1
  53 #define MSA_MODE_SEARCH         0x2
  54 #define MSA_MODE_AF_UPDATE      0x3
  55 #define MSA_MODE_JUMP           0x4
  56 #define MSA_MODE_CHECK          0x5
  57 #define MSA_MODE_LOAD           0x6
  58 #define MSA_MODE_END            0x7
  59 #define MSA_MODE_SHIFT          5
  60
  61 struct tef6862_state {
  62         struct v4l2_subdev sd;
  63         unsigned long freq;
  64 };
  65
  66 static inline struct tef6862_state *to_state(struct v4l2_subdev *sd)
  67 {
  68         return container_of(sd, struct tef6862_state, sd);
  69 }
  70
  71 static u16 tef6862_sigstr(struct i2c_client *client)
  72 {
  73         u8 buf[4];
  74         int err = i2c_master_recv(client, buf, sizeof(buf));
  75         if (err == sizeof(buf))
  76                 return buf[3] << 8;
  77         return 0;
  78 }
  79
  80 static int tef6862_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *v)
  81 {
  82         if (v->index > 0)
  83                 return -EINVAL;
  84
  85         /* only support FM for now */
  86         strlcpy(v->name, "FM", sizeof(v->name));
  87         v->type = V4L2_TUNER_RADIO;
  88         v->rangelow = TEF6862_LO_FREQ;
  89         v->rangehigh = TEF6862_HI_FREQ;
  90         v->rxsubchans = V4L2_TUNER_SUB_MONO;
  91         v->capability = V4L2_TUNER_CAP_LOW;
  92         v->audmode = V4L2_TUNER_MODE_STEREO;
  93         v->signal = tef6862_sigstr(v4l2_get_subdevdata(sd));
  94
  95         return 0;
  96 }
  97
  98 static int tef6862_s_tuner(struct v4l2_subdev *sd, const struct v4l2_tuner *v)
  99 {
 100         return v->index ? -EINVAL : 0;
 101 }
 102
 103 static int tef6862_s_frequency(struct v4l2_subdev *sd, const struct v4l2_frequency *f)
 104 {
 105         struct tef6862_state *state = to_state(sd);
 106         struct i2c_client *client = v4l2_get_subdevdata(sd);
 107         unsigned freq = f->frequency;
 108         u16 pll;
 109         u8 i2cmsg[3];
 110         int err;
 111
 112         if (f->tuner != 0)
 113                 return -EINVAL;
 114
 115         freq = clamp(freq, TEF6862_LO_FREQ, TEF6862_HI_FREQ);
 116         pll = 1964 + ((freq - TEF6862_LO_FREQ) * 20) / FREQ_MUL;
 117         i2cmsg[0] = (MSA_MODE_PRESET << MSA_MODE_SHIFT) | WM_SUB_PLLM;
 118         i2cmsg[1] = (pll >> 8) & 0xff;
 119         i2cmsg[2] = pll & 0xff;
 120
 121         err = i2c_master_send(client, i2cmsg, sizeof(i2cmsg));
 122         if (err != sizeof(i2cmsg))
 123                 return err < 0 ? err : -EIO;
 124
 125         state->freq = freq;
 126         return 0;
 127 }
 128
 129 static int tef6862_g_frequency(struct v4l2_subdev *sd, struct v4l2_frequency *f)
 130 {
 131         struct tef6862_state *state = to_state(sd);
 132
 133         if (f->tuner != 0)
 134                 return -EINVAL;
 135         f->type = V4L2_TUNER_RADIO;
 136         f->frequency = state->freq;
 137         return 0;
 138 }
 139
 140 static const struct v4l2_subdev_tuner_ops tef6862_tuner_ops = {
 141         .g_tuner = tef6862_g_tuner,
 142         .s_tuner = tef6862_s_tuner,
 143         .s_frequency = tef6862_s_frequency,
 144         .g_frequency = tef6862_g_frequency,
 145 };
 146
 147 static const struct v4l2_subdev_ops tef6862_ops = {
 148         .tuner = &tef6862_tuner_ops,
 149 };
 150
 151 /*
 152  * Generic i2c probe
 153  * concerning the addresses: i2c wants 7 bit (without the r/w bit), so '>>1'
 154  */
 155
 156 static int tef6862_probe(struct i2c_client *client,
 157                          const struct i2c_device_id *id)
 158 {
 159         struct tef6862_state *state;
 160         struct v4l2_subdev *sd;
 161
 162         /* Check if the adapter supports the needed features */
 163         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 164                 return -EIO;
 165
 166         v4l_info(client, "chip found @ 0x%02x (%s)\n",
 167                         client->addr << 1, client->adapter->name);
 168
 169         state = kzalloc(sizeof(struct tef6862_state), GFP_KERNEL);
 170         if (state == NULL)
 171                 return -ENOMEM;
 172         state->freq = TEF6862_LO_FREQ;
 173
 174         sd = &state->sd;
 175         v4l2_i2c_subdev_init(sd, client, &tef6862_ops);
 176
 177         return 0;
 178 }
 179
 180 static int tef6862_remove(struct i2c_client *client)
 181 {
 182         struct v4l2_subdev *sd = i2c_get_clientdata(client);
 183
 184         v4l2_device_unregister_subdev(sd);
 185         kfree(to_state(sd));
 186         return 0;
 187 }
 188
 189 static const struct i2c_device_id tef6862_id[] = {
 190         {DRIVER_NAME, 0},
 191         {},
 192 };
 193
 194 MODULE_DEVICE_TABLE(i2c, tef6862_id);
 195
 196 static struct i2c_driver tef6862_driver = {
 197         .driver = {
 198                 .owner  = THIS_MODULE,
 199                 .name   = DRIVER_NAME,
 200         },
 201         .probe          = tef6862_probe,
 202         .remove         = tef6862_remove,
 203         .id_table       = tef6862_id,
 204 };
 205
 206 module_i2c_driver(tef6862_driver);
 207
 208 MODULE_DESCRIPTION("TEF6862 Car Radio Enhanced Selectivity Tuner");
 209 MODULE_AUTHOR("Mocean Laboratories");
 210 MODULE_LICENSE("GPL v2");