drivers/media/dvb-frontends/tda8261.c

   1 /*
   2         TDA8261 8PSK/QPSK tuner driver
   3         Copyright (C) Manu Abraham (abraham.manu@gmail.com)
   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 as published by
   7         the Free Software Foundation; either version 2 of the License, or
   8         (at your option) any later version.
   9
  10         This program is distributed in the hope that it will be useful,
  11         but WITHOUT ANY WARRANTY; without even the implied warranty of
  12         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13         GNU General Public License for more details.
  14
  15         You should have received a copy of the GNU General Public License
  16         along with this program; if not, write to the Free Software
  17         Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18 */
  19
  20
  21 #include <linux/init.h>
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/slab.h>
  25
  26 #include <media/dvb_frontend.h>
  27 #include "tda8261.h"
  28
  29 struct tda8261_state {
  30         struct dvb_frontend             *fe;
  31         struct i2c_adapter              *i2c;
  32         const struct tda8261_config     *config;
  33
  34         /* state cache */
  35         u32 frequency;
  36         u32 bandwidth;
  37 };
  38
  39 static int tda8261_read(struct tda8261_state *state, u8 *buf)
  40 {
  41         const struct tda8261_config *config = state->config;
  42         int err = 0;
  43         struct i2c_msg msg = { .addr    = config->addr, .flags = I2C_M_RD,.buf = buf,  .len = 1 };
  44
  45         if ((err = i2c_transfer(state->i2c, &msg, 1)) != 1)
  46                 pr_err("%s: read error, err=%d\n", __func__, err);
  47
  48         return err;
  49 }
  50
  51 static int tda8261_write(struct tda8261_state *state, u8 *buf)
  52 {
  53         const struct tda8261_config *config = state->config;
  54         int err = 0;
  55         struct i2c_msg msg = { .addr = config->addr, .flags = 0, .buf = buf, .len = 4 };
  56
  57         if ((err = i2c_transfer(state->i2c, &msg, 1)) != 1)
  58                 pr_err("%s: write error, err=%d\n", __func__, err);
  59
  60         return err;
  61 }
  62
  63 static int tda8261_get_status(struct dvb_frontend *fe, u32 *status)
  64 {
  65         struct tda8261_state *state = fe->tuner_priv;
  66         u8 result = 0;
  67         int err = 0;
  68
  69         *status = 0;
  70
  71         if ((err = tda8261_read(state, &result)) < 0) {
  72                 pr_err("%s: I/O Error\n", __func__);
  73                 return err;
  74         }
  75         if ((result >> 6) & 0x01) {
  76                 pr_debug("%s: Tuner Phase Locked\n", __func__);
  77                 *status = 1;
  78         }
  79
  80         return err;
  81 }
  82
  83 static const u32 div_tab[] = { 2000, 1000,  500,  250,  125 }; /* kHz */
  84 static const u8  ref_div[] = { 0x00, 0x01, 0x02, 0x05, 0x07 };
  85
  86 static int tda8261_get_frequency(struct dvb_frontend *fe, u32 *frequency)
  87 {
  88         struct tda8261_state *state = fe->tuner_priv;
  89
  90         *frequency = state->frequency;
  91
  92         return 0;
  93 }
  94
  95 static int tda8261_set_params(struct dvb_frontend *fe)
  96 {
  97         struct dtv_frontend_properties *c = &fe->dtv_property_cache;
  98         struct tda8261_state *state = fe->tuner_priv;
  99         const struct tda8261_config *config = state->config;
 100         u32 frequency, N, status = 0;
 101         u8 buf[4];
 102         int err = 0;
 103
 104         /*
 105          * N = Max VCO Frequency / Channel Spacing
 106          * Max VCO Frequency = VCO frequency + (channel spacing - 1)
 107          * (to account for half channel spacing on either side)
 108          */
 109         frequency = c->frequency;
 110         if ((frequency < 950000) || (frequency > 2150000)) {
 111                 pr_warn("%s: Frequency beyond limits, frequency=%d\n",
 112                         __func__, frequency);
 113                 return -EINVAL;
 114         }
 115         N = (frequency + (div_tab[config->step_size] - 1)) / div_tab[config->step_size];
 116         pr_debug("%s: Step size=%d, Divider=%d, PG=0x%02x (%d)\n",
 117                 __func__, config->step_size, div_tab[config->step_size], N, N);
 118
 119         buf[0] = (N >> 8) & 0xff;
 120         buf[1] = N & 0xff;
 121         buf[2] = (0x01 << 7) | ((ref_div[config->step_size] & 0x07) << 1);
 122
 123         if (frequency < 1450000)
 124                 buf[3] = 0x00;
 125         else if (frequency < 2000000)
 126                 buf[3] = 0x40;
 127         else if (frequency < 2150000)
 128                 buf[3] = 0x80;
 129
 130         /* Set params */
 131         err = tda8261_write(state, buf);
 132         if (err < 0) {
 133                 pr_err("%s: I/O Error\n", __func__);
 134                 return err;
 135         }
 136         /* sleep for some time */
 137         pr_debug("%s: Waiting to Phase LOCK\n", __func__);
 138         msleep(20);
 139         /* check status */
 140         if ((err = tda8261_get_status(fe, &status)) < 0) {
 141                 pr_err("%s: I/O Error\n", __func__);
 142                 return err;
 143         }
 144         if (status == 1) {
 145                 pr_debug("%s: Tuner Phase locked: status=%d\n", __func__,
 146                          status);
 147                 state->frequency = frequency; /* cache successful state */
 148         } else {
 149                 pr_debug("%s: No Phase lock: status=%d\n", __func__, status);
 150         }
 151
 152         return 0;
 153 }
 154
 155 static void tda8261_release(struct dvb_frontend *fe)
 156 {
 157         struct tda8261_state *state = fe->tuner_priv;
 158
 159         fe->tuner_priv = NULL;
 160         kfree(state);
 161 }
 162
 163 static const struct dvb_tuner_ops tda8261_ops = {
 164
 165         .info = {
 166                 .name           = "TDA8261",
 167                 .frequency_min  =  950000,
 168                 .frequency_max  = 2150000,
 169                 .frequency_step = 0
 170         },
 171
 172         .set_params     = tda8261_set_params,
 173         .get_frequency  = tda8261_get_frequency,
 174         .get_status     = tda8261_get_status,
 175         .release        = tda8261_release
 176 };
 177
 178 struct dvb_frontend *tda8261_attach(struct dvb_frontend *fe,
 179                                     const struct tda8261_config *config,
 180                                     struct i2c_adapter *i2c)
 181 {
 182         struct tda8261_state *state = NULL;
 183
 184         if ((state = kzalloc(sizeof (struct tda8261_state), GFP_KERNEL)) == NULL)
 185                 goto exit;
 186
 187         state->config           = config;
 188         state->i2c              = i2c;
 189         state->fe               = fe;
 190         fe->tuner_priv          = state;
 191         fe->ops.tuner_ops       = tda8261_ops;
 192
 193         fe->ops.tuner_ops.info.frequency_step = div_tab[config->step_size];
 194
 195         pr_info("%s: Attaching TDA8261 8PSK/QPSK tuner\n", __func__);
 196
 197         return fe;
 198
 199 exit:
 200         kfree(state);
 201         return NULL;
 202 }
 203
 204 EXPORT_SYMBOL(tda8261_attach);
 205
 206 MODULE_AUTHOR("Manu Abraham");
 207 MODULE_DESCRIPTION("TDA8261 8PSK/QPSK Tuner");
 208 MODULE_LICENSE("GPL");