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
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/errno.h>
  18 #include <linux/kernel.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/i2c.h>
  21 #include <linux/slab.h>
  22 #include <media/v4l2-ioctl.h>
  23 #include <media/v4l2-device.h>
  24
  25 #define DRIVER_NAME "tef6862"
  26
  27 #define FREQ_MUL 16000
  28
  29 #define TEF6862_LO_FREQ (875U * FREQ_MUL / 10)
  30 #define TEF6862_HI_FREQ (108U * FREQ_MUL)
  31
  32 /* Write mode sub addresses */
  33 #define WM_SUB_BANDWIDTH        0x0
  34 #define WM_SUB_PLLM             0x1
  35 #define WM_SUB_PLLL             0x2
  36 #define WM_SUB_DAA              0x3
  37 #define WM_SUB_AGC              0x4
  38 #define WM_SUB_BAND             0x5
  39 #define WM_SUB_CONTROL          0x6
  40 #define WM_SUB_LEVEL            0x7
  41 #define WM_SUB_IFCF             0x8
  42 #define WM_SUB_IFCAP            0x9
  43 #define WM_SUB_ACD              0xA
  44 #define WM_SUB_TEST             0xF
  45
  46 /* Different modes of the MSA register */
  47 #define MSA_MODE_BUFFER         0x0
  48 #define MSA_MODE_PRESET         0x1
  49 #define MSA_MODE_SEARCH         0x2
  50 #define MSA_MODE_AF_UPDATE      0x3
  51 #define MSA_MODE_JUMP           0x4
  52 #define MSA_MODE_CHECK          0x5
  53 #define MSA_MODE_LOAD           0x6
  54 #define MSA_MODE_END            0x7
  55 #define MSA_MODE_SHIFT          5
  56
  57 struct tef6862_state {
  58         struct v4l2_subdev sd;
  59         unsigned long freq;
  60 };
  61
  62 static inline struct tef6862_state *to_state(struct v4l2_subdev *sd)
  63 {
  64         return container_of(sd, struct tef6862_state, sd);
  65 }
  66
  67 static u16 tef6862_sigstr(struct i2c_client *client)
  68 {
  69         u8 buf[4];
  70         int err = i2c_master_recv(client, buf, sizeof(buf));
  71         if (err == sizeof(buf))
  72                 return buf[3] << 8;
  73         return 0;
  74 }
  75
  76 static int tef6862_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *v)
  77 {
  78         if (v->index > 0)
  79                 return -EINVAL;
  80
  81         /* only support FM for now */
  82         strlcpy(v->name, "FM", sizeof(v->name));
  83         v->type = V4L2_TUNER_RADIO;
  84         v->rangelow = TEF6862_LO_FREQ;
  85         v->rangehigh = TEF6862_HI_FREQ;
  86         v->rxsubchans = V4L2_TUNER_SUB_MONO;
  87         v->capability = V4L2_TUNER_CAP_LOW;
  88         v->audmode = V4L2_TUNER_MODE_STEREO;
  89         v->signal = tef6862_sigstr(v4l2_get_subdevdata(sd));
  90
  91         return 0;
  92 }
  93
  94 static int tef6862_s_tuner(struct v4l2_subdev *sd, const struct v4l2_tuner *v)
  95 {
  96         return v->index ? -EINVAL : 0;
  97 }
  98
  99 static int tef6862_s_frequency(struct v4l2_subdev *sd, const struct v4l2_frequency *f)
 100 {
 101         struct tef6862_state *state = to_state(sd);
 102         struct i2c_client *client = v4l2_get_subdevdata(sd);
 103         unsigned freq = f->frequency;
 104         u16 pll;
 105         u8 i2cmsg[3];
 106         int err;
 107
 108         if (f->tuner != 0)
 109                 return -EINVAL;
 110
 111         freq = clamp(freq, TEF6862_LO_FREQ, TEF6862_HI_FREQ);
 112         pll = 1964 + ((freq - TEF6862_LO_FREQ) * 20) / FREQ_MUL;
 113         i2cmsg[0] = (MSA_MODE_PRESET << MSA_MODE_SHIFT) | WM_SUB_PLLM;
 114         i2cmsg[1] = (pll >> 8) & 0xff;
 115         i2cmsg[2] = pll & 0xff;
 116
 117         err = i2c_master_send(client, i2cmsg, sizeof(i2cmsg));
 118         if (err != sizeof(i2cmsg))
 119                 return err < 0 ? err : -EIO;
 120
 121         state->freq = freq;
 122         return 0;
 123 }
 124
 125 static int tef6862_g_frequency(struct v4l2_subdev *sd, struct v4l2_frequency *f)
 126 {
 127         struct tef6862_state *state = to_state(sd);
 128
 129         if (f->tuner != 0)
 130                 return -EINVAL;
 131         f->type = V4L2_TUNER_RADIO;
 132         f->frequency = state->freq;
 133         return 0;
 134 }
 135
 136 static const struct v4l2_subdev_tuner_ops tef6862_tuner_ops = {
 137         .g_tuner = tef6862_g_tuner,
 138         .s_tuner = tef6862_s_tuner,
 139         .s_frequency = tef6862_s_frequency,
 140         .g_frequency = tef6862_g_frequency,
 141 };
 142
 143 static const struct v4l2_subdev_ops tef6862_ops = {
 144         .tuner = &tef6862_tuner_ops,
 145 };
 146
 147 /*
 148  * Generic i2c probe
 149  * concerning the addresses: i2c wants 7 bit (without the r/w bit), so '>>1'
 150  */
 151
 152 static int tef6862_probe(struct i2c_client *client,
 153                          const struct i2c_device_id *id)
 154 {
 155         struct tef6862_state *state;
 156         struct v4l2_subdev *sd;
 157
 158         /* Check if the adapter supports the needed features */
 159         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 160                 return -EIO;
 161
 162         v4l_info(client, "chip found @ 0x%02x (%s)\n",
 163                         client->addr << 1, client->adapter->name);
 164
 165         state = kzalloc(sizeof(struct tef6862_state), GFP_KERNEL);
 166         if (state == NULL)
 167                 return -ENOMEM;
 168         state->freq = TEF6862_LO_FREQ;
 169
 170         sd = &state->sd;
 171         v4l2_i2c_subdev_init(sd, client, &tef6862_ops);
 172
 173         return 0;
 174 }
 175
 176 static int tef6862_remove(struct i2c_client *client)
 177 {
 178         struct v4l2_subdev *sd = i2c_get_clientdata(client);
 179
 180         v4l2_device_unregister_subdev(sd);
 181         kfree(to_state(sd));
 182         return 0;
 183 }
 184
 185 static const struct i2c_device_id tef6862_id[] = {
 186         {DRIVER_NAME, 0},
 187         {},
 188 };
 189
 190 MODULE_DEVICE_TABLE(i2c, tef6862_id);
 191
 192 static struct i2c_driver tef6862_driver = {
 193         .driver = {
 194                 .name   = DRIVER_NAME,
 195         },
 196         .probe          = tef6862_probe,
 197         .remove         = tef6862_remove,
 198         .id_table       = tef6862_id,
 199 };
 200
 201 module_i2c_driver(tef6862_driver);
 202
 203 MODULE_DESCRIPTION("TEF6862 Car Radio Enhanced Selectivity Tuner");
 204 MODULE_AUTHOR("Mocean Laboratories");
 205 MODULE_LICENSE("GPL v2");