text: /*     
   **********************************************************************
   *     ecard.c - E-card initialization code
   *     Copyright 1999, 2000 Creative Labs, Inc. 
   * 
   ********************************************************************** 
   * 
   *     Date                 Author          Summary of changes 
   *     ----                 ------          ------------------ 
   *     October 20, 1999     Bertrand Lee    base code release 
   * 
   ********************************************************************** 
   * 
   *     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 "ecard.h"
  #include "hwaccess.h"
  
  /* Private routines */
  static void ecard_setadcgain(struct emu10k1_card *, struct ecard_state *, u16);
  static void ecard_write(struct emu10k1_card *, u32);
  
  /**************************************************************************
   * @func Set the gain of the ECARD's CS3310 Trim/gain controller.  The
   * trim value consists of a 16bit value which is composed of two
   * 8 bit gain/trim values, one for the left channel and one for the
   * right channel.  The following table maps from the Gain/Attenuation
   * value in decibels into the corresponding bit pattern for a single
   * channel.
   */
  
  static void ecard_setadcgain(struct emu10k1_card *card, struct ecard_state *ecard, u16 gain)
  {
  	u32 currbit;
  	ecard->adc_gain = gain;
  
  	/* Enable writing to the TRIM registers */
  	ecard_write(card, ecard->control_bits & ~EC_TRIM_CSN);
  
  	/* Do it again to insure that we meet hold time requirements */
  	ecard_write(card, ecard->control_bits & ~EC_TRIM_CSN);
  
  	for (currbit = (1L << 15); currbit; currbit >>= 1) {
  
  		u32 value = ecard->control_bits & ~(EC_TRIM_CSN|EC_TRIM_SDATA);
  
  		if (gain & currbit)
  		      value |= EC_TRIM_SDATA;
  
  		/* Clock the bit */
  		ecard_write(card, value);
  		ecard_write(card, value | EC_TRIM_SCLK);
  		ecard_write(card, value);
  	}
  
  	ecard_write(card, ecard->control_bits);
  }
  
  /**************************************************************************
   * @func Clock bits into the Ecard's control latch.  The Ecard uses a
   *  control latch will is loaded bit-serially by toggling the Modem control
   *  lines from function 2 on the E8010.  This function hides these details
   *  and presents the illusion that we are actually writing to a distinct
   *  register.
   */
  static void ecard_write(struct emu10k1_card *card, u32 value)
  {
  	u16 count;
  	u32 data, hcvalue;
  	unsigned long flags;
  
  	spin_lock_irqsave(&card->lock, flags);
  
  	hcvalue = inl(card->iobase + HCFG) & ~(HOOKN_BIT|HANDN_BIT|PULSEN_BIT);
  
  	outl(card->iobase + HCFG, hcvalue);
  
  	for (count = 0 ; count < EC_NUM_CONTROL_BITS; count++) {
  	
  		/* Set up the value */
  		data = ((value & 0x1) ? PULSEN_BIT : 0);
  		value >>= 1;
  
  		outl(card->iobase + HCFG, hcvalue | data);
  
  		/* Clock the shift register */
  		outl(card->iobase + HCFG, hcvalue | data | HANDN_BIT);
  		outl(card->iobase + HCFG, hcvalue | data);
  	}
  
  	/* Latch the bits */
  	outl(card->iobase + HCFG, hcvalue | HOOKN_BIT);
  	outl(card->iobase + HCFG, hcvalue);
  
  	spin_unlock_irqrestore(&card->lock, flags);
  }
  
  void __devinit emu10k1_ecard_init(struct emu10k1_card *card)
  {
  	u32 hcvalue;
  	struct ecard_state ecard;
  
  	/* Set up the initial settings */
  	ecard.mux0_setting = EC_DEFAULT_SPDIF0_SEL;
  	ecard.mux1_setting = EC_DEFAULT_SPDIF1_SEL;
  	ecard.mux2_setting = 0;
  	ecard.adc_gain = EC_DEFAULT_ADC_GAIN;
  	ecard.control_bits = EC_RAW_RUN_MODE | 
                               EC_SPDIF0_SELECT(ecard.mux0_setting) |
  			     EC_SPDIF1_SELECT(ecard.mux1_setting);
  
  
  	/* Step 0: Set the codec type in the hardware control register 
  	 * and enable audio output */
  	hcvalue = emu10k1_readfn0(card, HCFG);
  	emu10k1_writefn0(card, HCFG, hcvalue | HCFG_AUDIOENABLE | HCFG_CODECFORMAT_I2S);
  
  	/* Step 1: Turn off the led and deassert TRIM_CS */
  	ecard_write(card, EC_ADCCAL | EC_LEDN | EC_TRIM_CSN);
  
  	/* Step 2: Calibrate the ADC and DAC */
  	ecard_write(card, EC_DACCAL | EC_LEDN | EC_TRIM_CSN);
  
  
  	current->state = TASK_INTERRUPTIBLE;
  	schedule_timeout(HZ);
  
  	/* Step 4: Switch off the DAC and ADC calibration.  Note
  	 * That ADC_CAL is actually an inverted signal, so we assert
  	 * it here to stop calibration.  */
  	ecard_write(card, EC_ADCCAL | EC_LEDN | EC_TRIM_CSN);
  
  	/* Step 4: Switch into run mode */
  	ecard_write(card, ecard.control_bits);
  
  	/* Step 5: Set the analog input gain */
  	ecard_setadcgain(card, &ecard, ecard.adc_gain);
  }
  
  
  