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tda826x.c
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1  /*
2  Driver for Philips tda8262/tda8263 DVBS Silicon tuners
3 
4  (c) 2006 Andrew de Quincey
5 
6  This program is free software; you can redistribute it and/or modify
7  it under the terms of the GNU General Public License as published by
8  the Free Software Foundation; either version 2 of the License, or
9  (at your option) any later version.
10 
11  This program is distributed in the hope that it will be useful,
12  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 
15  GNU General Public License for more details.
16 
17  You should have received a copy of the GNU General Public License
18  along with this program; if not, write to the Free Software
19  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 
21  */
22 
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/dvb/frontend.h>
26 #include <asm/types.h>
27 
28 #include "tda826x.h"
29 
30 static int debug;
31 #define dprintk(args...) \
32  do { \
33  if (debug) printk(KERN_DEBUG "tda826x: " args); \
34  } while (0)
35 
36 struct tda826x_priv {
37  /* i2c details */
39  struct i2c_adapter *i2c;
42 };
43 
44 static int tda826x_release(struct dvb_frontend *fe)
45 {
46  kfree(fe->tuner_priv);
47  fe->tuner_priv = NULL;
48  return 0;
49 }
50 
51 static int tda826x_sleep(struct dvb_frontend *fe)
52 {
53  struct tda826x_priv *priv = fe->tuner_priv;
54  int ret;
55  u8 buf [] = { 0x00, 0x8d };
56  struct i2c_msg msg = { .addr = priv->i2c_address, .flags = 0, .buf = buf, .len = 2 };
57 
58  dprintk("%s:\n", __func__);
59 
60  if (!priv->has_loopthrough)
61  buf[1] = 0xad;
62 
63  if (fe->ops.i2c_gate_ctrl)
64  fe->ops.i2c_gate_ctrl(fe, 1);
65  if ((ret = i2c_transfer (priv->i2c, &msg, 1)) != 1) {
66  dprintk("%s: i2c error\n", __func__);
67  }
68  if (fe->ops.i2c_gate_ctrl)
69  fe->ops.i2c_gate_ctrl(fe, 0);
70 
71  return (ret == 1) ? 0 : ret;
72 }
73 
74 static int tda826x_set_params(struct dvb_frontend *fe)
75 {
77  struct tda826x_priv *priv = fe->tuner_priv;
78  int ret;
79  u32 div;
80  u32 ksyms;
81  u32 bandwidth;
82  u8 buf [11];
83  struct i2c_msg msg = { .addr = priv->i2c_address, .flags = 0, .buf = buf, .len = 11 };
84 
85  dprintk("%s:\n", __func__);
86 
87  div = (p->frequency + (1000-1)) / 1000;
88 
89  /* BW = ((1 + RO) * SR/2 + 5) * 1.3 [SR in MSPS, BW in MHz] */
90  /* with R0 = 0.35 and some transformations: */
91  ksyms = p->symbol_rate / 1000;
92  bandwidth = (878 * ksyms + 6500000) / 1000000 + 1;
93  if (bandwidth < 5)
94  bandwidth = 5;
95  else if (bandwidth > 36)
96  bandwidth = 36;
97 
98  buf[0] = 0x00; // subaddress
99  buf[1] = 0x09; // powerdown RSSI + the magic value 1
100  if (!priv->has_loopthrough)
101  buf[1] |= 0x20; // power down loopthrough if not needed
102  buf[2] = (1<<5) | 0x0b; // 1Mhz + 0.45 VCO
103  buf[3] = div >> 7;
104  buf[4] = div << 1;
105  buf[5] = ((bandwidth - 5) << 3) | 7; /* baseband cut-off */
106  buf[6] = 0xfe; // baseband gain 9 db + no RF attenuation
107  buf[7] = 0x83; // charge pumps at high, tests off
108  buf[8] = 0x80; // recommended value 4 for AMPVCO + disable ports.
109  buf[9] = 0x1a; // normal caltime + recommended values for SELTH + SELVTL
110  buf[10] = 0xd4; // recommended value 13 for BBIAS + unknown bit set on
111 
112  if (fe->ops.i2c_gate_ctrl)
113  fe->ops.i2c_gate_ctrl(fe, 1);
114  if ((ret = i2c_transfer (priv->i2c, &msg, 1)) != 1) {
115  dprintk("%s: i2c error\n", __func__);
116  }
117  if (fe->ops.i2c_gate_ctrl)
118  fe->ops.i2c_gate_ctrl(fe, 0);
119 
120  priv->frequency = div * 1000;
121 
122  return (ret == 1) ? 0 : ret;
123 }
124 
125 static int tda826x_get_frequency(struct dvb_frontend *fe, u32 *frequency)
126 {
127  struct tda826x_priv *priv = fe->tuner_priv;
128  *frequency = priv->frequency;
129  return 0;
130 }
131 
132 static struct dvb_tuner_ops tda826x_tuner_ops = {
133  .info = {
134  .name = "Philips TDA826X",
135  .frequency_min = 950000,
136  .frequency_max = 2175000
137  },
138  .release = tda826x_release,
139  .sleep = tda826x_sleep,
140  .set_params = tda826x_set_params,
141  .get_frequency = tda826x_get_frequency,
142 };
143 
144 struct dvb_frontend *tda826x_attach(struct dvb_frontend *fe, int addr, struct i2c_adapter *i2c, int has_loopthrough)
145 {
146  struct tda826x_priv *priv = NULL;
147  u8 b1 [] = { 0, 0 };
148  struct i2c_msg msg[2] = {
149  { .addr = addr, .flags = 0, .buf = NULL, .len = 0 },
150  { .addr = addr, .flags = I2C_M_RD, .buf = b1, .len = 2 }
151  };
152  int ret;
153 
154  dprintk("%s:\n", __func__);
155 
156  if (fe->ops.i2c_gate_ctrl)
157  fe->ops.i2c_gate_ctrl(fe, 1);
158  ret = i2c_transfer (i2c, msg, 2);
159  if (fe->ops.i2c_gate_ctrl)
160  fe->ops.i2c_gate_ctrl(fe, 0);
161 
162  if (ret != 2)
163  return NULL;
164  if (!(b1[1] & 0x80))
165  return NULL;
166 
167  priv = kzalloc(sizeof(struct tda826x_priv), GFP_KERNEL);
168  if (priv == NULL)
169  return NULL;
170 
171  priv->i2c_address = addr;
172  priv->i2c = i2c;
173  priv->has_loopthrough = has_loopthrough;
174 
175  memcpy(&fe->ops.tuner_ops, &tda826x_tuner_ops, sizeof(struct dvb_tuner_ops));
176 
177  fe->tuner_priv = priv;
178 
179  return fe;
180 }
182 
183 module_param(debug, int, 0644);
184 MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
185 
186 MODULE_DESCRIPTION("DVB TDA826x driver");
187 MODULE_AUTHOR("Andrew de Quincey");
188 MODULE_LICENSE("GPL");