/* $XFree86: xc/programs/Xserver/hw/xfree86/drivers/nsc/gfx/i2c_gpio.c,v 1.1 2002/12/10 15:12:26 alanh Exp $ */
/*
 * $Workfile: i2c_gpio.c $
 *
 * This file contains routines to write to and read from the I2C bus using
 * the GPIO pins of the CS5530.
 *
 * NSC_LIC_ALTERNATIVE_PREAMBLE
 *
 * Revision 1.0
 *
 * National Semiconductor Alternative GPL-BSD License
 *
 * National Semiconductor Corporation licenses this software 
 * ("Software"):
 *
 *      Durango
 *
 * under one of the two following licenses, depending on how the 
 * Software is received by the Licensee.
 * 
 * If this Software is received as part of the Linux Framebuffer or
 * other GPL licensed software, then the GPL license designated 
 * NSC_LIC_GPL applies to this Software; in all other circumstances 
 * then the BSD-style license designated NSC_LIC_BSD shall apply.
 *
 * END_NSC_LIC_ALTERNATIVE_PREAMBLE */

/* NSC_LIC_BSD
 *
 * National Semiconductor Corporation Open Source License for Durango
 *
 * (BSD License with Export Notice)
 *
 * Copyright (c) 1999-2001
 * National Semiconductor Corporation.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions 
 * are met: 
 *
 *   * Redistributions of source code must retain the above copyright 
 *     notice, this list of conditions and the following disclaimer. 
 *
 *   * Redistributions in binary form must reproduce the above 
 *     copyright notice, this list of conditions and the following 
 *     disclaimer in the documentation and/or other materials provided 
 *     with the distribution. 
 *
 *   * Neither the name of the National Semiconductor Corporation nor 
 *     the names of its contributors may be used to endorse or promote 
 *     products derived from this software without specific prior 
 *     written permission. 
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
 * NATIONAL SEMICONDUCTOR CORPORATION OR CONTRIBUTORS BE LIABLE FOR ANY 
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER 
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE,
 * INTELLECTUAL PROPERTY INFRINGEMENT, OR OTHERWISE) ARISING IN ANY WAY 
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
 * OF SUCH DAMAGE.
 *
 * EXPORT LAWS: THIS LICENSE ADDS NO RESTRICTIONS TO THE EXPORT LAWS OF 
 * YOUR JURISDICTION. It is licensee's responsibility to comply with 
 * any export regulations applicable in licensee's jurisdiction. Under 
 * CURRENT (2001) U.S. export regulations this software 
 * is eligible for export from the U.S. and can be downloaded by or 
 * otherwise exported or reexported worldwide EXCEPT to U.S. embargoed 
 * destinations which include Cuba, Iraq, Libya, North Korea, Iran, 
 * Syria, Sudan, Afghanistan and any other country to which the U.S. 
 * has embargoed goods and services. 
 *
 * END_NSC_LIC_BSD */

/* NSC_LIC_GPL
 *
 * National Semiconductor Corporation Gnu General Public License for Durango
 *
 * (GPL License with Export Notice)
 *
 * Copyright (c) 1999-2001
 * National Semiconductor Corporation.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted 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  
 *
 * In addition to the terms of the GNU General Public License, neither 
 * the name of the National Semiconductor Corporation nor the names of 
 * its contributors may be used to endorse or promote products derived 
 * from this software without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
 * NATIONAL SEMICONDUCTOR CORPORATION OR CONTRIBUTORS BE LIABLE FOR ANY 
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER 
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE, 
 * INTELLECTUAL PROPERTY INFRINGEMENT, OR OTHERWISE) ARISING IN ANY WAY 
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
 * OF SUCH DAMAGE. See the GNU General Public License for more details. 
 *
 * EXPORT LAWS: THIS LICENSE ADDS NO RESTRICTIONS TO THE EXPORT LAWS OF 
 * YOUR JURISDICTION. It is licensee's responsibility to comply with 
 * any export regulations applicable in licensee's jurisdiction. Under 
 * CURRENT (2001) U.S. export regulations this software 
 * is eligible for export from the U.S. and can be downloaded by or 
 * otherwise exported or reexported worldwide EXCEPT to U.S. embargoed 
 * destinations which include Cuba, Iraq, Libya, North Korea, Iran, 
 * Syria, Sudan, Afghanistan and any other country to which the U.S. 
 * has embargoed goods and services. 
 *
 * You should have received a copy of the GNU General Public License 
 * along with this file; if not, write to the Free Software Foundation, 
 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 
 *
 * END_NSC_LIC_GPL */

/* STATIC VARIABLES TO STORE WHAT GPIO PINS TO USE */

int gpio_clock = 0;
int gpio_data = 0;

static int g_initialized = 0;

#define	I2CWRITE		0x00	/* Write address */
#define	I2CREAD			0x01	/* Read address */

#define	I2CACK			0x00	/* Ack value */
#define	I2CNACK			0x01	/* Not - ack value */

#define		CS5530_ID	(0x80000000 | (0x00<<16) | (0x12<<11) | (0<<8) | 0x00)
#define		CS5530_GPIO	(0x80000000 | (0x00<<16) | (0x12<<11) | (0<<8) | 0x90)
#define		SDA		0x0800
#define		SCL		0x0400
#define		SDADIR	0x0008
#define		SCLDIR	0x0004

int I2C_init(void);
void I2C_cleanup(void);

int I2C_Read(unsigned char address, unsigned int reg, unsigned long *p_value,
	     unsigned int bytes);
int I2C_Write(unsigned char address, unsigned int reg, unsigned long value,
	      unsigned int bytes);
int I2CAL_init(void);
void I2CAL_cleanup(void);

void I2CAL_output_clock(int state);
void I2CAL_output_data(int state);
unsigned char I2CAL_input_data(void);

void I2CAL_set_data_for_input(void);
void I2CAL_set_data_for_output(void);

void SendI2CStart(void);
void SendI2CData(unsigned char inData);

unsigned char ReceiveI2CAck(void);
void SendI2CStop(void);
void SendI2CNack(void);
void SendI2CAck(void);
unsigned char ReceiveI2CData(void);

int gpio_i2c_reset(unsigned char busnum, short adr, char freq);
int gpio_i2c_write(unsigned char busnum, unsigned char chipadr,
		   unsigned char subadr, unsigned char bytes,
		   unsigned char *data);
int gpio_i2c_read(unsigned char busnum, unsigned char chipadr,
		  unsigned char subadr, unsigned char bytes,
		  unsigned char *data);
int gpio_i2c_select_gpio(int clock, int data);
int gpio_i2c_init(void);
void gpio_i2c_cleanup(void);

/* ### ADD ### ANY LOCAL ROUTINE DEFINITIONS SPECIFIC TO GPIO */

/*---------------------------------------------------------------------------
 * gfx_i2c_reset
 *
 * This routine resets the I2C bus.
 *---------------------------------------------------------------------------
 */

#if GFX_I2C_DYNAMIC
int
gpio_i2c_reset(unsigned char busnum, short adr, char freq)
#else
int
gfx_i2c_reset(unsigned char busnum, short adr, char freq)
#endif
{
   /* ### ADD ### Any code needed to reset the state of the GPIOs. */
   return GFX_STATUS_OK;
}

/*---------------------------------------------------------------------------
 * gfx_i2c_select_gpio
 *
 * This routine selects which GPIO pins to use.
 *---------------------------------------------------------------------------
 */
#if GFX_I2C_DYNAMIC
int
gpio_i2c_select_gpio(int clock, int data)
#else
int
gfx_i2c_select_gpio(int clock, int data)
#endif
{
   gpio_clock = clock;
   gpio_data = data;
   return (0);
}

/*---------------------------------------------------------------------------
 * gfx_i2c_write
 *
 * This routine writes data to the specified I2C address.
 *---------------------------------------------------------------------------
 */
#if GFX_I2C_DYNAMIC
int
gpio_i2c_write(unsigned char busnum, unsigned char address, unsigned char reg,
	       unsigned char bytes, unsigned char *value)
#else
int
gfx_i2c_write(unsigned char busnum, unsigned char address, unsigned char reg,
	      unsigned char bytes, unsigned char *value)
#endif
{
   /* ### ADD ### CODE TO WRITE BYTE TO I2B BUS */

   int restart_count = 0;

   while (restart_count++ < 5) {
      /* set the access pointer register. */
      /* The address is shifted left by one to make room for Read/Write bit */
      SendI2CStart();
      SendI2CData((char)((address << 1) | I2CWRITE));
      if (!ReceiveI2CAck()) {
	 SendI2CStop();
	 gfx_delay_milliseconds(10);
	 continue;
      }
      SendI2CData((unsigned char)reg);
      if (!ReceiveI2CAck()) {
	 SendI2CStop();
	 gfx_delay_milliseconds(10);
	 continue;
      }

      /* write the first byte */
      SendI2CData(*value);
      if (!ReceiveI2CAck()) {
	 SendI2CStop();
	 gfx_delay_milliseconds(10);
	 continue;
      }

      /* write the second byte. */
      if (bytes == 2) {
	 SendI2CData(*(value + 1));
	 if (!ReceiveI2CAck()) {
	    SendI2CStop();
	    gfx_delay_milliseconds(10);
	    continue;
	 }
      }

      /* done. */
      SendI2CStop();

      return 0;
   }

   return (0);

}

/*---------------------------------------------------------------------------
 * gfx_i2c_read
 *
 * This routine reads data from the specified I2C address.
 *---------------------------------------------------------------------------
 */
#if GFX_I2C_DYNAMIC
int
gpio_i2c_read(unsigned char busnum, unsigned char address, unsigned char reg,
	      unsigned char bytes, unsigned char *p_value)
#else
int
gfx_i2c_read(unsigned char busnum, unsigned char address, unsigned char reg,
	     unsigned char bytes, unsigned char *p_value)
#endif
{
   /* ### ADD ### CODE TO WRITE BYTE TO I2B BUS */
   /* For now return clock and data pins */

   int restart_count = 0;

   if (!p_value)
      return (1);

   while (restart_count++ < 5) {
      /* set the access pointer register. */
      /* The address is shifted left by one to make room for Read/Write bit  */
      SendI2CStart();
      SendI2CData((char)((address << 1) | I2CWRITE));
      if (!ReceiveI2CAck()) {
	 SendI2CStop();
	 gfx_delay_milliseconds(10);
	 continue;
      }
      SendI2CData((unsigned char)(reg & 0xFF));
      SendI2CNack();

      /* read the first data byte. */
      SendI2CStart();
      SendI2CData((char)((address << 1) | I2CREAD));
      if (!ReceiveI2CAck()) {
	 SendI2CStop();
	 gfx_delay_milliseconds(10);
	 continue;
      }
      *p_value = ReceiveI2CData();

      /* read the second byte. */
      if (bytes == 2) {
	 SendI2CAck();
	 *(p_value + 1) = ReceiveI2CData();
      }

      /* done. */
      SendI2CNack();
      SendI2CStop();

      return 0;
   }

   return (1);
}

/* Added i2c/gpio code to test fs451 chip. */

/*
//----------------------------------------------------------------------
//
//	void SendI2CStart(void)
//	
//	Sends an I2C start signal on the bus.
//	
//----------------------------------------------------------------------
*/
void
SendI2CStart(void)
{
   I2CAL_output_data(1);
   I2CAL_output_clock(1);
   I2CAL_output_data(0);
   I2CAL_output_clock(0);
}

/*
//----------------------------------------------------------------------
//
//	void SendI2CStop(void)
//	
//	Sends an I2C stop signal on the bus.
//	
//----------------------------------------------------------------------
*/
void
SendI2CStop(void)
{
   I2CAL_output_data(0);
   I2CAL_output_clock(1);
   I2CAL_output_data(1);
}

/*
//----------------------------------------------------------------------
//
//	void SendI2CAck(void)
//	
//	Sends the Ack signal on the I2C bus.
//	
//----------------------------------------------------------------------
*/
void
SendI2CAck(void)
{
   I2CAL_output_data(0);
   I2CAL_output_clock(1);
   I2CAL_output_clock(0);
}

/*
//----------------------------------------------------------------------
//
//	void SendI2CNack(void)
//	
//	Sends the Nt-Ack signal on the I2C bus.
//	
//----------------------------------------------------------------------
*/
void
SendI2CNack(void)
{
   I2CAL_output_data(1);
   I2CAL_output_clock(1);
   I2CAL_output_clock(0);
}

/*
//----------------------------------------------------------------------
//
//	UInt8 SendI2CData( UInt8 inData )
//	
//	Sends a byte of data on the I2C bus and returns the TRUE if the slave ACK'd
//	the data.
//	
//	Input:	inData			- the byte of data to send          
//	Output:	(return)		- TRUE (1) if ACK was received, FALSE (0) if not
//	
//----------------------------------------------------------------------
*/
void
SendI2CData(unsigned char inData)
{
   unsigned char bit;

   /* Send all 8 bits of data byte, MSB to LSB */
   for (bit = 0x80; bit != 0; bit >>= 1) {
      if (inData & bit)
	 I2CAL_output_data(1);
      else
	 I2CAL_output_data(0);

      I2CAL_output_clock(1);
      I2CAL_output_clock(0);
   }
}

/*
//----------------------------------------------------------------------
//
//	UInt8 ReceiveI2CAck(  )
//	
//	Receives the Ack (or Nack) from the slave. 
//	
//	Output:	(return) - TRUE (1) if ACK was received, FALSE (0) if not
//	
//----------------------------------------------------------------------
*/
unsigned char
ReceiveI2CAck(void)
{
   unsigned char bit;

   /* Test for Ack/Nack */
   I2CAL_set_data_for_input();
   I2CAL_output_data(1);
   I2CAL_output_clock(1);
   bit = I2CAL_input_data();
   I2CAL_output_clock(0);
   I2CAL_set_data_for_output();
   return !bit;
}

/*	
//----------------------------------------------------------------------
//
//	unsigned char ReceiveI2CData(void)
//	
//	Receives a byte of data from the I2C bus.
//	
//	Output:	(return) - The data byte recehved from the bus
//	
//----------------------------------------------------------------------
*/
unsigned char
ReceiveI2CData(void)
{
   unsigned char data = 0;
   unsigned char x;

   /* make sure the data line is released */
   I2CAL_set_data_for_input();
   I2CAL_output_data(1);

   /* shift in the data */
   for (x = 0; x < 8; x++) {
      /* shift the data left   */
      I2CAL_output_clock(1);
      data <<= 1;
      data |= I2CAL_input_data();
      I2CAL_output_clock(0);
   }

   I2CAL_set_data_for_output();
   I2CAL_output_data(1);
   return data;
}

/*
//----------------------------------------------------------------------
//
//	void I2C_init(void)
//	
//	This routine initializes the I2C interface. Clients of the I2C.c
//	will call this routine before calling any other routine in the I2C.c
//	
//----------------------------------------------------------------------
*/

#if GFX_I2C_DYNAMIC
int
gpio_i2c_init(void)
#else
int
gfx_i2c_init(void)
#endif
{
   int errc;

   /* init I2CAL */
   errc = I2CAL_init();
   if (errc)
      return errc;

   /* set the clock and data lines to the proper states */
   I2CAL_output_clock(1);
   I2CAL_output_data(1);
   I2CAL_set_data_for_output();

   SendI2CStart();
   SendI2CStop();
   SendI2CStop();

   g_initialized = 1;

   return 0;
}

/*
//----------------------------------------------------------------------
//	
//	void I2C_cleanup(void)
//	
//	This routine disables the I2C interface. Clients of the I2C.c will not
//	call any other I2C routine after calling this routine.
//	
//----------------------------------------------------------------------
*/

#if GFX_I2C_DYNAMIC
void
gpio_i2c_cleanup(void)
#else
void
gfx_i2c_cleanup(void)
#endif
{
   if (g_initialized) {

      /* set the clock and data lines to a harmless state */
      I2CAL_output_clock(1);
      I2CAL_output_data(1);

      g_initialized = 0;
   }

   I2CAL_cleanup();
}

int
I2CAL_init(void)
{
   unsigned long l_reg;
   unsigned short reg;

   /* initialize the i2c port. */
   l_reg = gfx_pci_config_read(CS5530_GPIO);

   if (l_reg != 0x01001078)
      return 1;

   l_reg = gfx_pci_config_read(CS5530_GPIO);
   reg = (unsigned short)l_reg;

   /* both outputs, both high. */
   reg |= (SDADIR | SCLDIR | SDA | SCL);
   l_reg = reg;
   gfx_pci_config_write(CS5530_GPIO, l_reg);

   g_initialized = 1;

   return 0;
}

void
I2CAL_cleanup(void)
{
   if (g_initialized) {

      g_initialized = 0;
   }
}

/*
//--------------------------------------------------------------------------------
//
//	set the I2C clock line state
//
//--------------------------------------------------------------------------------
*/
void
I2CAL_output_clock(int inState)
{
   unsigned short reg;
   unsigned long value;

   value = gfx_pci_config_read(CS5530_GPIO);
   reg = (unsigned short)value;

   if (inState) {			/* write a 1. */
      reg |= SCL;
   } else {				/* write a 0. */
      reg &= ~SCL;
   }

   value = reg;
   gfx_pci_config_write(CS5530_GPIO, value);

   /* hold it for a minimum of 4.7us */
   gfx_delay_microseconds(5);
}

/*
//--------------------------------------------------------------------------------
//
//	set the I2C data line state
//
//--------------------------------------------------------------------------------
*/
void
I2CAL_output_data(int inState)
{
   unsigned short reg;
   unsigned long value;

   value = gfx_pci_config_read(CS5530_GPIO);
   reg = (unsigned short)value;

   if (inState) {			/* write a 1. */
      reg |= SDA;
   } else {
      /* write a 0. */
      reg &= ~SDA;
   }
   value = reg;
   gfx_pci_config_write(CS5530_GPIO, value);

   /* 250 ns setup time */
   gfx_delay_microseconds(1);
}

/*
//--------------------------------------------------------------------------------
//
//	read the state of the data line
//
//--------------------------------------------------------------------------------
*/
unsigned char
I2CAL_input_data(void)
{
   unsigned short reg;
   unsigned long value;

   value = gfx_pci_config_read(CS5530_GPIO);
   reg = (unsigned short)value;

   if (reg & SDA)
      return 1;
   else
      return 0;
}

/*
//--------------------------------------------------------------------------------
//
//	set the I2C data for input mode
//
//--------------------------------------------------------------------------------
*/
void
I2CAL_set_data_for_input(void)
{
   unsigned short reg;
   unsigned long value;

   value = gfx_pci_config_read(CS5530_GPIO);
   reg = (unsigned short)value;

   reg &= ~SDADIR;

   value = reg;

   gfx_pci_config_write(CS5530_GPIO, value);
}

/*
//--------------------------------------------------------------------------------
//
//	set the I2C data for output mode
//
//--------------------------------------------------------------------------------
*/
void
I2CAL_set_data_for_output(void)
{
   unsigned short reg;
   unsigned long value;

   value = gfx_pci_config_read(CS5530_GPIO);
   reg = (unsigned short)value;
   reg |= SDADIR;
   value = reg;

   gfx_pci_config_write(CS5530_GPIO, value);

}

/* END OF FILE */