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cx22700.c

/*
    Conexant cx22700 DVB OFDM demodulator driver

    Copyright (C) 2001-2002 Convergence Integrated Media GmbH
      Holger Waechtler <holger@convergence.de>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/slab.h>
#include "dvb_frontend.h"
#include "cx22700.h"


struct cx22700_state {

      struct i2c_adapter* i2c;

      const struct cx22700_config* config;

      struct dvb_frontend frontend;
};


static int debug;
#define dprintk(args...) \
      do { \
            if (debug) printk(KERN_DEBUG "cx22700: " args); \
      } while (0)

static u8 init_tab [] = {
      0x04, 0x10,
      0x05, 0x09,
      0x06, 0x00,
      0x08, 0x04,
      0x09, 0x00,
      0x0a, 0x01,
      0x15, 0x40,
      0x16, 0x10,
      0x17, 0x87,
      0x18, 0x17,
      0x1a, 0x10,
      0x25, 0x04,
      0x2e, 0x00,
      0x39, 0x00,
      0x3a, 0x04,
      0x45, 0x08,
      0x46, 0x02,
      0x47, 0x05,
};


static int cx22700_writereg (struct cx22700_state* state, u8 reg, u8 data)
{
      int ret;
      u8 buf [] = { reg, data };
      struct i2c_msg msg = { .addr = state->config->demod_address, .flags = 0, .buf = buf, .len = 2 };

      dprintk ("%s\n", __FUNCTION__);

      ret = i2c_transfer (state->i2c, &msg, 1);

      if (ret != 1)
            printk("%s: writereg error (reg == 0x%02x, val == 0x%02x, ret == %i)\n",
                  __FUNCTION__, reg, data, ret);

      return (ret != 1) ? -1 : 0;
}

static int cx22700_readreg (struct cx22700_state* state, u8 reg)
{
      int ret;
      u8 b0 [] = { reg };
      u8 b1 [] = { 0 };
      struct i2c_msg msg [] = { { .addr = state->config->demod_address, .flags = 0, .buf = b0, .len = 1 },
                     { .addr = state->config->demod_address, .flags = I2C_M_RD, .buf = b1, .len = 1 } };

      dprintk ("%s\n", __FUNCTION__);

      ret = i2c_transfer (state->i2c, msg, 2);

      if (ret != 2) return -EIO;

      return b1[0];
}

static int cx22700_set_inversion (struct cx22700_state* state, int inversion)
{
      u8 val;

      dprintk ("%s\n", __FUNCTION__);

      switch (inversion) {
      case INVERSION_AUTO:
            return -EOPNOTSUPP;
      case INVERSION_ON:
            val = cx22700_readreg (state, 0x09);
            return cx22700_writereg (state, 0x09, val | 0x01);
      case INVERSION_OFF:
            val = cx22700_readreg (state, 0x09);
            return cx22700_writereg (state, 0x09, val & 0xfe);
      default:
            return -EINVAL;
      }
}

static int cx22700_set_tps (struct cx22700_state *state, struct dvb_ofdm_parameters *p)
{
      static const u8 qam_tab [4] = { 0, 1, 0, 2 };
      static const u8 fec_tab [6] = { 0, 1, 2, 0, 3, 4 };
      u8 val;

      dprintk ("%s\n", __FUNCTION__);

      if (p->code_rate_HP < FEC_1_2 || p->code_rate_HP > FEC_7_8)
            return -EINVAL;

      if (p->code_rate_LP < FEC_1_2 || p->code_rate_LP > FEC_7_8)
            return -EINVAL;

      if (p->code_rate_HP == FEC_4_5 || p->code_rate_LP == FEC_4_5)
            return -EINVAL;

      if (p->guard_interval < GUARD_INTERVAL_1_32 ||
          p->guard_interval > GUARD_INTERVAL_1_4)
            return -EINVAL;

      if (p->transmission_mode != TRANSMISSION_MODE_2K &&
          p->transmission_mode != TRANSMISSION_MODE_8K)
            return -EINVAL;

      if (p->constellation != QPSK &&
          p->constellation != QAM_16 &&
          p->constellation != QAM_64)
            return -EINVAL;

      if (p->hierarchy_information < HIERARCHY_NONE ||
          p->hierarchy_information > HIERARCHY_4)
            return -EINVAL;

      if (p->bandwidth < BANDWIDTH_8_MHZ && p->bandwidth > BANDWIDTH_6_MHZ)
            return -EINVAL;

      if (p->bandwidth == BANDWIDTH_7_MHZ)
            cx22700_writereg (state, 0x09, cx22700_readreg (state, 0x09 | 0x10));
      else
            cx22700_writereg (state, 0x09, cx22700_readreg (state, 0x09 & ~0x10));

      val = qam_tab[p->constellation - QPSK];
      val |= p->hierarchy_information - HIERARCHY_NONE;

      cx22700_writereg (state, 0x04, val);

      val = fec_tab[p->code_rate_HP - FEC_1_2] << 3;
      val |= fec_tab[p->code_rate_LP - FEC_1_2];

      cx22700_writereg (state, 0x05, val);

      val = (p->guard_interval - GUARD_INTERVAL_1_32) << 2;
      val |= p->transmission_mode - TRANSMISSION_MODE_2K;

      cx22700_writereg (state, 0x06, val);

      cx22700_writereg (state, 0x08, 0x04 | 0x02);  /* use user tps parameters */
      cx22700_writereg (state, 0x08, 0x04);         /* restart aquisition */

      return 0;
}

static int cx22700_get_tps (struct cx22700_state* state, struct dvb_ofdm_parameters *p)
{
      static const fe_modulation_t qam_tab [3] = { QPSK, QAM_16, QAM_64 };
      static const fe_code_rate_t fec_tab [5] = { FEC_1_2, FEC_2_3, FEC_3_4,
                                        FEC_5_6, FEC_7_8 };
      u8 val;

      dprintk ("%s\n", __FUNCTION__);

      if (!(cx22700_readreg(state, 0x07) & 0x20))  /*  tps valid? */
            return -EAGAIN;

      val = cx22700_readreg (state, 0x01);

      if ((val & 0x7) > 4)
            p->hierarchy_information = HIERARCHY_AUTO;
      else
            p->hierarchy_information = HIERARCHY_NONE + (val & 0x7);

      if (((val >> 3) & 0x3) > 2)
            p->constellation = QAM_AUTO;
      else
            p->constellation = qam_tab[(val >> 3) & 0x3];

      val = cx22700_readreg (state, 0x02);

      if (((val >> 3) & 0x07) > 4)
            p->code_rate_HP = FEC_AUTO;
      else
            p->code_rate_HP = fec_tab[(val >> 3) & 0x07];

      if ((val & 0x07) > 4)
            p->code_rate_LP = FEC_AUTO;
      else
            p->code_rate_LP = fec_tab[val & 0x07];

      val = cx22700_readreg (state, 0x03);

      p->guard_interval = GUARD_INTERVAL_1_32 + ((val >> 6) & 0x3);
      p->transmission_mode = TRANSMISSION_MODE_2K + ((val >> 5) & 0x1);

      return 0;
}

static int cx22700_init (struct dvb_frontend* fe)

{     struct cx22700_state* state = fe->demodulator_priv;
      int i;

      dprintk("cx22700_init: init chip\n");

      cx22700_writereg (state, 0x00, 0x02);   /*  soft reset */
      cx22700_writereg (state, 0x00, 0x00);

      msleep(10);

      for (i=0; i<sizeof(init_tab); i+=2)
            cx22700_writereg (state, init_tab[i], init_tab[i+1]);

      cx22700_writereg (state, 0x00, 0x01);

      return 0;
}

static int cx22700_read_status(struct dvb_frontend* fe, fe_status_t* status)
{
      struct cx22700_state* state = fe->demodulator_priv;

      u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
               | (cx22700_readreg (state, 0x0e) << 1);
      u8 sync = cx22700_readreg (state, 0x07);

      *status = 0;

      if (rs_ber < 0xff00)
            *status |= FE_HAS_SIGNAL;

      if (sync & 0x20)
            *status |= FE_HAS_CARRIER;

      if (sync & 0x10)
            *status |= FE_HAS_VITERBI;

      if (sync & 0x10)
            *status |= FE_HAS_SYNC;

      if (*status == 0x0f)
            *status |= FE_HAS_LOCK;

      return 0;
}

static int cx22700_read_ber(struct dvb_frontend* fe, u32* ber)
{
      struct cx22700_state* state = fe->demodulator_priv;

      *ber = cx22700_readreg (state, 0x0c) & 0x7f;
      cx22700_writereg (state, 0x0c, 0x00);

      return 0;
}

static int cx22700_read_signal_strength(struct dvb_frontend* fe, u16* signal_strength)
{
      struct cx22700_state* state = fe->demodulator_priv;

      u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
               | (cx22700_readreg (state, 0x0e) << 1);
      *signal_strength = ~rs_ber;

      return 0;
}

static int cx22700_read_snr(struct dvb_frontend* fe, u16* snr)
{
      struct cx22700_state* state = fe->demodulator_priv;

      u16 rs_ber = (cx22700_readreg (state, 0x0d) << 9)
               | (cx22700_readreg (state, 0x0e) << 1);
      *snr = ~rs_ber;

      return 0;
}

static int cx22700_read_ucblocks(struct dvb_frontend* fe, u32* ucblocks)
{
      struct cx22700_state* state = fe->demodulator_priv;

      *ucblocks = cx22700_readreg (state, 0x0f);
      cx22700_writereg (state, 0x0f, 0x00);

      return 0;
}

static int cx22700_set_frontend(struct dvb_frontend* fe, struct dvb_frontend_parameters *p)
{
      struct cx22700_state* state = fe->demodulator_priv;

      cx22700_writereg (state, 0x00, 0x02); /* XXX CHECKME: soft reset*/
      cx22700_writereg (state, 0x00, 0x00);

      if (fe->ops.tuner_ops.set_params) {
            fe->ops.tuner_ops.set_params(fe, p);
            if (fe->ops.i2c_gate_ctrl) fe->ops.i2c_gate_ctrl(fe, 0);
      }

      cx22700_set_inversion (state, p->inversion);
      cx22700_set_tps (state, &p->u.ofdm);
      cx22700_writereg (state, 0x37, 0x01);  /* PAL loop filter off */
      cx22700_writereg (state, 0x00, 0x01);  /* restart acquire */

      return 0;
}

static int cx22700_get_frontend(struct dvb_frontend* fe, struct dvb_frontend_parameters *p)
{
      struct cx22700_state* state = fe->demodulator_priv;
      u8 reg09 = cx22700_readreg (state, 0x09);

      p->inversion = reg09 & 0x1 ? INVERSION_ON : INVERSION_OFF;
      return cx22700_get_tps (state, &p->u.ofdm);
}

static int cx22700_i2c_gate_ctrl(struct dvb_frontend* fe, int enable)
{
      struct cx22700_state* state = fe->demodulator_priv;

      if (enable) {
            return cx22700_writereg(state, 0x0a, 0x00);
      } else {
            return cx22700_writereg(state, 0x0a, 0x01);
      }
}

static int cx22700_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings* fesettings)
{
      fesettings->min_delay_ms = 150;
      fesettings->step_size = 166667;
      fesettings->max_drift = 166667*2;
      return 0;
}

static void cx22700_release(struct dvb_frontend* fe)
{
      struct cx22700_state* state = fe->demodulator_priv;
      kfree(state);
}

static struct dvb_frontend_ops cx22700_ops;

struct dvb_frontend* cx22700_attach(const struct cx22700_config* config,
                            struct i2c_adapter* i2c)
{
      struct cx22700_state* state = NULL;

      /* allocate memory for the internal state */
      state = kmalloc(sizeof(struct cx22700_state), GFP_KERNEL);
      if (state == NULL) goto error;

      /* setup the state */
      state->config = config;
      state->i2c = i2c;

      /* check if the demod is there */
      if (cx22700_readreg(state, 0x07) < 0) goto error;

      /* create dvb_frontend */
      memcpy(&state->frontend.ops, &cx22700_ops, sizeof(struct dvb_frontend_ops));
      state->frontend.demodulator_priv = state;
      return &state->frontend;

error:
      kfree(state);
      return NULL;
}

static struct dvb_frontend_ops cx22700_ops = {

      .info = {
            .name             = "Conexant CX22700 DVB-T",
            .type             = FE_OFDM,
            .frequency_min          = 470000000,
            .frequency_max          = 860000000,
            .frequency_stepsize     = 166667,
            .caps = FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
                  FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
                  FE_CAN_QPSK | FE_CAN_QAM_16 | FE_CAN_QAM_64 |
                  FE_CAN_RECOVER
      },

      .release = cx22700_release,

      .init = cx22700_init,
      .i2c_gate_ctrl = cx22700_i2c_gate_ctrl,

      .set_frontend = cx22700_set_frontend,
      .get_frontend = cx22700_get_frontend,
      .get_tune_settings = cx22700_get_tune_settings,

      .read_status = cx22700_read_status,
      .read_ber = cx22700_read_ber,
      .read_signal_strength = cx22700_read_signal_strength,
      .read_snr = cx22700_read_snr,
      .read_ucblocks = cx22700_read_ucblocks,
};

module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");

MODULE_DESCRIPTION("Conexant CX22700 DVB-T Demodulator driver");
MODULE_AUTHOR("Holger Waechtler");
MODULE_LICENSE("GPL");

EXPORT_SYMBOL(cx22700_attach);

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