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mt2060.c
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1 /*
2  * Driver for Microtune MT2060 "Single chip dual conversion broadband tuner"
3  *
4  * Copyright (c) 2006 Olivier DANET <[email protected]>
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 /* In that file, frequencies are expressed in kiloHertz to avoid 32 bits overflows */
23 
24 #include <linux/module.h>
25 #include <linux/delay.h>
26 #include <linux/dvb/frontend.h>
27 #include <linux/i2c.h>
28 #include <linux/slab.h>
29 
30 #include "dvb_frontend.h"
31 
32 #include "mt2060.h"
33 #include "mt2060_priv.h"
34 
35 static int debug;
36 module_param(debug, int, 0644);
37 MODULE_PARM_DESC(debug, "Turn on/off debugging (default:off).");
38 
39 #define dprintk(args...) do { if (debug) {printk(KERN_DEBUG "MT2060: " args); printk("\n"); }} while (0)
40 
41 // Reads a single register
42 static int mt2060_readreg(struct mt2060_priv *priv, u8 reg, u8 *val)
43 {
44  struct i2c_msg msg[2] = {
45  { .addr = priv->cfg->i2c_address, .flags = 0, .buf = &reg, .len = 1 },
46  { .addr = priv->cfg->i2c_address, .flags = I2C_M_RD, .buf = val, .len = 1 },
47  };
48 
49  if (i2c_transfer(priv->i2c, msg, 2) != 2) {
50  printk(KERN_WARNING "mt2060 I2C read failed\n");
51  return -EREMOTEIO;
52  }
53  return 0;
54 }
55 
56 // Writes a single register
57 static int mt2060_writereg(struct mt2060_priv *priv, u8 reg, u8 val)
58 {
59  u8 buf[2] = { reg, val };
60  struct i2c_msg msg = {
61  .addr = priv->cfg->i2c_address, .flags = 0, .buf = buf, .len = 2
62  };
63 
64  if (i2c_transfer(priv->i2c, &msg, 1) != 1) {
65  printk(KERN_WARNING "mt2060 I2C write failed\n");
66  return -EREMOTEIO;
67  }
68  return 0;
69 }
70 
71 // Writes a set of consecutive registers
72 static int mt2060_writeregs(struct mt2060_priv *priv,u8 *buf, u8 len)
73 {
74  struct i2c_msg msg = {
75  .addr = priv->cfg->i2c_address, .flags = 0, .buf = buf, .len = len
76  };
77  if (i2c_transfer(priv->i2c, &msg, 1) != 1) {
78  printk(KERN_WARNING "mt2060 I2C write failed (len=%i)\n",(int)len);
79  return -EREMOTEIO;
80  }
81  return 0;
82 }
83 
84 // Initialisation sequences
85 // LNABAND=3, NUM1=0x3C, DIV1=0x74, NUM2=0x1080, DIV2=0x49
86 static u8 mt2060_config1[] = {
87  REG_LO1C1,
88  0x3F, 0x74, 0x00, 0x08, 0x93
89 };
90 
91 // FMCG=2, GP2=0, GP1=0
92 static u8 mt2060_config2[] = {
94  0x20, 0x1E, 0x30, 0xff, 0x80, 0xff, 0x00, 0x2c, 0x42
95 };
96 
97 // VGAG=3, V1CSE=1
98 
99 #ifdef MT2060_SPURCHECK
100 /* The function below calculates the frequency offset between the output frequency if2
101  and the closer cross modulation subcarrier between lo1 and lo2 up to the tenth harmonic */
102 static int mt2060_spurcalc(u32 lo1,u32 lo2,u32 if2)
103 {
104  int I,J;
105  int dia,diamin,diff;
106  diamin=1000000;
107  for (I = 1; I < 10; I++) {
108  J = ((2*I*lo1)/lo2+1)/2;
109  diff = I*(int)lo1-J*(int)lo2;
110  if (diff < 0) diff=-diff;
111  dia = (diff-(int)if2);
112  if (dia < 0) dia=-dia;
113  if (diamin > dia) diamin=dia;
114  }
115  return diamin;
116 }
117 
118 #define BANDWIDTH 4000 // kHz
119 
120 /* Calculates the frequency offset to add to avoid spurs. Returns 0 if no offset is needed */
121 static int mt2060_spurcheck(u32 lo1,u32 lo2,u32 if2)
122 {
123  u32 Spur,Sp1,Sp2;
124  int I,J;
125  I=0;
126  J=1000;
127 
128  Spur=mt2060_spurcalc(lo1,lo2,if2);
129  if (Spur < BANDWIDTH) {
130  /* Potential spurs detected */
131  dprintk("Spurs before : f_lo1: %d f_lo2: %d (kHz)",
132  (int)lo1,(int)lo2);
133  I=1000;
134  Sp1 = mt2060_spurcalc(lo1+I,lo2+I,if2);
135  Sp2 = mt2060_spurcalc(lo1-I,lo2-I,if2);
136 
137  if (Sp1 < Sp2) {
138  J=-J; I=-I; Spur=Sp2;
139  } else
140  Spur=Sp1;
141 
142  while (Spur < BANDWIDTH) {
143  I += J;
144  Spur = mt2060_spurcalc(lo1+I,lo2+I,if2);
145  }
146  dprintk("Spurs after : f_lo1: %d f_lo2: %d (kHz)",
147  (int)(lo1+I),(int)(lo2+I));
148  }
149  return I;
150 }
151 #endif
152 
153 #define IF2 36150 // IF2 frequency = 36.150 MHz
154 #define FREF 16000 // Quartz oscillator 16 MHz
155 
156 static int mt2060_set_params(struct dvb_frontend *fe)
157 {
159  struct mt2060_priv *priv;
160  int ret=0;
161  int i=0;
162  u32 freq;
163  u8 lnaband;
164  u32 f_lo1,f_lo2;
165  u32 div1,num1,div2,num2;
166  u8 b[8];
167  u32 if1;
168 
169  priv = fe->tuner_priv;
170 
171  if1 = priv->if1_freq;
172  b[0] = REG_LO1B1;
173  b[1] = 0xFF;
174 
175  if (fe->ops.i2c_gate_ctrl)
176  fe->ops.i2c_gate_ctrl(fe, 1); /* open i2c_gate */
177 
178  mt2060_writeregs(priv,b,2);
179 
180  freq = c->frequency / 1000; /* Hz -> kHz */
181 
182  f_lo1 = freq + if1 * 1000;
183  f_lo1 = (f_lo1 / 250) * 250;
184  f_lo2 = f_lo1 - freq - IF2;
185  // From the Comtech datasheet, the step used is 50kHz. The tuner chip could be more precise
186  f_lo2 = ((f_lo2 + 25) / 50) * 50;
187  priv->frequency = (f_lo1 - f_lo2 - IF2) * 1000,
188 
189 #ifdef MT2060_SPURCHECK
190  // LO-related spurs detection and correction
191  num1 = mt2060_spurcheck(f_lo1,f_lo2,IF2);
192  f_lo1 += num1;
193  f_lo2 += num1;
194 #endif
195  //Frequency LO1 = 16MHz * (DIV1 + NUM1/64 )
196  num1 = f_lo1 / (FREF / 64);
197  div1 = num1 / 64;
198  num1 &= 0x3f;
199 
200  // Frequency LO2 = 16MHz * (DIV2 + NUM2/8192 )
201  num2 = f_lo2 * 64 / (FREF / 128);
202  div2 = num2 / 8192;
203  num2 &= 0x1fff;
204 
205  if (freq <= 95000) lnaband = 0xB0; else
206  if (freq <= 180000) lnaband = 0xA0; else
207  if (freq <= 260000) lnaband = 0x90; else
208  if (freq <= 335000) lnaband = 0x80; else
209  if (freq <= 425000) lnaband = 0x70; else
210  if (freq <= 480000) lnaband = 0x60; else
211  if (freq <= 570000) lnaband = 0x50; else
212  if (freq <= 645000) lnaband = 0x40; else
213  if (freq <= 730000) lnaband = 0x30; else
214  if (freq <= 810000) lnaband = 0x20; else lnaband = 0x10;
215 
216  b[0] = REG_LO1C1;
217  b[1] = lnaband | ((num1 >>2) & 0x0F);
218  b[2] = div1;
219  b[3] = (num2 & 0x0F) | ((num1 & 3) << 4);
220  b[4] = num2 >> 4;
221  b[5] = ((num2 >>12) & 1) | (div2 << 1);
222 
223  dprintk("IF1: %dMHz",(int)if1);
224  dprintk("PLL freq=%dkHz f_lo1=%dkHz f_lo2=%dkHz",(int)freq,(int)f_lo1,(int)f_lo2);
225  dprintk("PLL div1=%d num1=%d div2=%d num2=%d",(int)div1,(int)num1,(int)div2,(int)num2);
226  dprintk("PLL [1..5]: %2x %2x %2x %2x %2x",(int)b[1],(int)b[2],(int)b[3],(int)b[4],(int)b[5]);
227 
228  mt2060_writeregs(priv,b,6);
229 
230  //Waits for pll lock or timeout
231  i = 0;
232  do {
233  mt2060_readreg(priv,REG_LO_STATUS,b);
234  if ((b[0] & 0x88)==0x88)
235  break;
236  msleep(4);
237  i++;
238  } while (i<10);
239 
240  if (fe->ops.i2c_gate_ctrl)
241  fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */
242 
243  return ret;
244 }
245 
246 static void mt2060_calibrate(struct mt2060_priv *priv)
247 {
248  u8 b = 0;
249  int i = 0;
250 
251  if (mt2060_writeregs(priv,mt2060_config1,sizeof(mt2060_config1)))
252  return;
253  if (mt2060_writeregs(priv,mt2060_config2,sizeof(mt2060_config2)))
254  return;
255 
256  /* initialize the clock output */
257  mt2060_writereg(priv, REG_VGAG, (priv->cfg->clock_out << 6) | 0x30);
258 
259  do {
260  b |= (1 << 6); // FM1SS;
261  mt2060_writereg(priv, REG_LO2C1,b);
262  msleep(20);
263 
264  if (i == 0) {
265  b |= (1 << 7); // FM1CA;
266  mt2060_writereg(priv, REG_LO2C1,b);
267  b &= ~(1 << 7); // FM1CA;
268  msleep(20);
269  }
270 
271  b &= ~(1 << 6); // FM1SS
272  mt2060_writereg(priv, REG_LO2C1,b);
273 
274  msleep(20);
275  i++;
276  } while (i < 9);
277 
278  i = 0;
279  while (i++ < 10 && mt2060_readreg(priv, REG_MISC_STAT, &b) == 0 && (b & (1 << 6)) == 0)
280  msleep(20);
281 
282  if (i <= 10) {
283  mt2060_readreg(priv, REG_FM_FREQ, &priv->fmfreq); // now find out, what is fmreq used for :)
284  dprintk("calibration was successful: %d", (int)priv->fmfreq);
285  } else
286  dprintk("FMCAL timed out");
287 }
288 
289 static int mt2060_get_frequency(struct dvb_frontend *fe, u32 *frequency)
290 {
291  struct mt2060_priv *priv = fe->tuner_priv;
292  *frequency = priv->frequency;
293  return 0;
294 }
295 
296 static int mt2060_get_if_frequency(struct dvb_frontend *fe, u32 *frequency)
297 {
298  *frequency = IF2 * 1000;
299  return 0;
300 }
301 
302 static int mt2060_init(struct dvb_frontend *fe)
303 {
304  struct mt2060_priv *priv = fe->tuner_priv;
305  int ret;
306 
307  if (fe->ops.i2c_gate_ctrl)
308  fe->ops.i2c_gate_ctrl(fe, 1); /* open i2c_gate */
309 
310  ret = mt2060_writereg(priv, REG_VGAG,
311  (priv->cfg->clock_out << 6) | 0x33);
312 
313  if (fe->ops.i2c_gate_ctrl)
314  fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */
315 
316  return ret;
317 }
318 
319 static int mt2060_sleep(struct dvb_frontend *fe)
320 {
321  struct mt2060_priv *priv = fe->tuner_priv;
322  int ret;
323 
324  if (fe->ops.i2c_gate_ctrl)
325  fe->ops.i2c_gate_ctrl(fe, 1); /* open i2c_gate */
326 
327  ret = mt2060_writereg(priv, REG_VGAG,
328  (priv->cfg->clock_out << 6) | 0x30);
329 
330  if (fe->ops.i2c_gate_ctrl)
331  fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */
332 
333  return ret;
334 }
335 
336 static int mt2060_release(struct dvb_frontend *fe)
337 {
338  kfree(fe->tuner_priv);
339  fe->tuner_priv = NULL;
340  return 0;
341 }
342 
343 static const struct dvb_tuner_ops mt2060_tuner_ops = {
344  .info = {
345  .name = "Microtune MT2060",
346  .frequency_min = 48000000,
347  .frequency_max = 860000000,
348  .frequency_step = 50000,
349  },
350 
351  .release = mt2060_release,
352 
353  .init = mt2060_init,
354  .sleep = mt2060_sleep,
355 
356  .set_params = mt2060_set_params,
357  .get_frequency = mt2060_get_frequency,
358  .get_if_frequency = mt2060_get_if_frequency,
359 };
360 
361 /* This functions tries to identify a MT2060 tuner by reading the PART/REV register. This is hasty. */
362 struct dvb_frontend * mt2060_attach(struct dvb_frontend *fe, struct i2c_adapter *i2c, struct mt2060_config *cfg, u16 if1)
363 {
364  struct mt2060_priv *priv = NULL;
365  u8 id = 0;
366 
367  priv = kzalloc(sizeof(struct mt2060_priv), GFP_KERNEL);
368  if (priv == NULL)
369  return NULL;
370 
371  priv->cfg = cfg;
372  priv->i2c = i2c;
373  priv->if1_freq = if1;
374 
375  if (fe->ops.i2c_gate_ctrl)
376  fe->ops.i2c_gate_ctrl(fe, 1); /* open i2c_gate */
377 
378  if (mt2060_readreg(priv,REG_PART_REV,&id) != 0) {
379  kfree(priv);
380  return NULL;
381  }
382 
383  if (id != PART_REV) {
384  kfree(priv);
385  return NULL;
386  }
387  printk(KERN_INFO "MT2060: successfully identified (IF1 = %d)\n", if1);
388  memcpy(&fe->ops.tuner_ops, &mt2060_tuner_ops, sizeof(struct dvb_tuner_ops));
389 
390  fe->tuner_priv = priv;
391 
392  mt2060_calibrate(priv);
393 
394  if (fe->ops.i2c_gate_ctrl)
395  fe->ops.i2c_gate_ctrl(fe, 0); /* close i2c_gate */
396 
397  return fe;
398 }
400 
401 MODULE_AUTHOR("Olivier DANET");
402 MODULE_DESCRIPTION("Microtune MT2060 silicon tuner driver");
403 MODULE_LICENSE("GPL");