root/lm-sensors/trunk/kernel/busses/i2c-i801.c @ 528

/*
    i801.c - Part of lm_sensors, Linux kernel modules for hardware
              monitoring
    Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl> and
    Philip Edelbrock <phil@netroedge.com>

    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.
*/

/*
    This driver supports the Intel 82801AA and 82801AB
    I/O Controller Hubs (ICH). They are similar to the PIIX4 and are part
    of Intel's '810' chipset. See the doc/busses directory for details.
*/      

/* Note: we assume there can only be one I801, with one SMBus interface */

#include <linux/module.h>
#include <linux/pci.h>
#include <asm/io.h>
#include <linux/kernel.h>
#include <linux/stddef.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/i2c.h>
#include "version.h"
#include "compat.h"

#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,1,54))
#include <linux/bios32.h>
#endif

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,53)
#include <linux/init.h>
#else
#define __init
#define __initdata
#endif

/* I801 SMBus address offsets */
#define SMBHSTSTS (0 + i801_smba)
#define SMBHSTCNT (2 + i801_smba)
#define SMBHSTCMD (3 + i801_smba)
#define SMBHSTADD (4 + i801_smba)
#define SMBHSTDAT0 (5 + i801_smba)
#define SMBHSTDAT1 (6 + i801_smba)
#define SMBBLKDAT (7 + i801_smba)

/* PCI Address Constants */
#define SMBBA     0x020
#define SMBHSTCFG 0x040
#define SMBREV    0x008

/* Other settings */
#define MAX_TIMEOUT 500
#define  ENABLE_INT9 0

/* I801 constants */
#define I801_QUICK      0x00
#define I801_BYTE       0x04
#define I801_BYTE_DATA  0x08
#define I801_WORD_DATA  0x0C
#define I801_BLOCK_DATA 0x14

/* insmod parameters */

/* If force is set to anything different from 0, we forcibly enable the
   I801. DANGEROUS! */
static int force = 0;
MODULE_PARM(force,"i");
MODULE_PARM_DESC(force,"Forcibly enable the I801. DANGEROUS!");

/* If force_addr is set to anything different from 0, we forcibly enable
   the I801 at the given address. VERY DANGEROUS! */
static int force_addr = 0;
MODULE_PARM(force_addr,"i");
MODULE_PARM_DESC(force_addr,"Forcibly enable the I801 at the given address. "
                            "EXTREMELY DANGEROUS!");

static int __init i801_cleanup(void);
static int i801_setup(void);
static s32 i801_access(struct i2c_adapter *adap, u8 addr, char read_write,
                        u8 command, int size, union i2c_smbus_data * data);
static void i801_do_pause( unsigned int amount );
static int i801_transaction(void);
static void i801_inc(struct i2c_adapter *adapter);
static void i801_dec(struct i2c_adapter *adapter);

#ifdef MODULE
extern int init_module(void);
extern int cleanup_module(void);
#endif /* MODULE */

static struct i2c_algorithm smbus_algorithm = {
  /* name */            "Non-I2C SMBus adapter",
  /* id */              I2C_ALGO_SMBUS,
  /* master_xfer */     NULL,
  /* smbus_access */    i801_access,
  /* slave_send */      NULL,
  /* slave_rcv */       NULL,
  /* algo_control */    NULL,
};

static struct i2c_adapter i801_adapter = {
  "unset",
  I2C_ALGO_SMBUS | I2C_HW_SMBUS_I801,
  &smbus_algorithm,
  NULL,
  i801_inc,
  i801_dec,
  NULL,
  NULL,
};

static int __initdata i801_initialized;
static unsigned short i801_smba = 0;


/* Detect whether a I801 can be found, and initialize it, where necessary.
   Note the differences between kernels with the old PCI BIOS interface and
   newer kernels with the real PCI interface. In compat.h some things are
   defined to make the transition easier. */
int i801_setup(void)
{
  int error_return=0;
  unsigned char temp;

#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,54))
  struct pci_dev *I801_dev;
#else
  unsigned char I801_bus, I801_devfn;
  int i,res;
#endif

  /* First check whether we can access PCI at all */
  if (pci_present() == 0) {
    printk("i2c-i801.o: Error: No PCI-bus found!\n");
    error_return=-ENODEV;
    goto END;
  }

  /* Look for the I801, function 3 */
  /* Have to check for both the 82801AA and 82801AB */
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,54))
  /* Note: we keep on searching until we have found 'function 3' */
  I801_dev = NULL;
  do
    I801_dev = pci_find_device(PCI_VENDOR_ID_INTEL, 
                                PCI_DEVICE_ID_INTEL_82801AA_3, I801_dev);
  while(I801_dev && (PCI_FUNC(I801_dev->devfn) != 3));
  if(I801_dev == NULL) {
    do
      I801_dev = pci_find_device(PCI_VENDOR_ID_INTEL, 
                                  PCI_DEVICE_ID_INTEL_82801AB_3, I801_dev);
    while(I801_dev && (PCI_FUNC(I801_dev->devfn) != 3));
  }
  if(I801_dev == NULL) {
#else /* LINUX_VERSION_CODE < KERNEL_VERSION(2,1,54) */
  for (i = 0; 
       ! (res = pcibios_find_device(PCI_VENDOR_ID_INTEL,
                                    PCI_DEVICE_ID_INTEL_82801AA_3,
                                    i,&I801_bus, &I801_devfn)) && 
         PCI_FUNC(I801_devfn) != 3; 
       i++);
  if (res) {
    for (i = 0; 
         ! (res = pcibios_find_device(PCI_VENDOR_ID_INTEL,
                                      PCI_DEVICE_ID_INTEL_82801AB_3,
                                      i,&I801_bus, &I801_devfn)) && 
           PCI_FUNC(I801_devfn) != 3; 
         i++);
  }
  if (res) {
#endif /* LINUX_VERSION_CODE >= KERNEL_VERSION(2,1,54) */
    printk("i2c-i801.o: Error: Can't detect I801, function 3!\n");
    error_return=-ENODEV;
    goto END;
  } 

/* Determine the address of the SMBus areas */
  if (force_addr) {
    i801_smba = force_addr & 0xfff0;
    force = 0;
  } else {

    pci_read_config_word_united(I801_dev, I801_bus ,I801_devfn,
                                SMBBA,&i801_smba);
    i801_smba &= 0xfff0;
  }

  if (check_region(i801_smba, 8)) {
    printk("i2c-i801.o: I801_smb region 0x%x already in use!\n", i801_smba);
    error_return=-ENODEV;
    goto END;
  }

  pci_read_config_byte_united(I801_dev, I801_bus, I801_devfn,
                              SMBHSTCFG, &temp);
/* If force_addr is set, we program the new address here. Just to make
   sure, we disable the I801 first. */
  if (force_addr) {
    pci_write_config_byte_united(I801_dev, I801_bus, I801_devfn,
                                SMBHSTCFG, temp & 0xfe);
    pci_write_config_word_united(I801_dev, I801_bus ,I801_devfn,
                                 SMBBA,i801_smba);
    pci_write_config_byte_united(I801_dev, I801_bus, I801_devfn,
                                SMBHSTCFG, temp | 0x01);
    printk("i2c-i801.o: WARNING: I801 SMBus interface set to new "
           "address %04x!\n",i801_smba);
  } else if ((temp & 1) == 0) {
    if (force) {
/* This should never need to be done, but has been noted that
   many Dell machines have the SMBus interface on the PIIX4
   disabled!? NOTE: This assumes I/O space and other allocations WERE
   done by the Bios!  Don't complain if your hardware does weird 
   things after enabling this. :') Check for Bios updates before
   resorting to this.  */
      pci_write_config_byte_united(I801_dev, I801_bus, I801_devfn,
                                       SMBHSTCFG, temp | 1);
      printk("i2c-i801.o: WARNING: I801 SMBus interface has been FORCEFULLY "
             "ENABLED!\n");
    } else {
      printk("SMBUS: Error: Host SMBus controller not enabled!\n");     
      error_return=-ENODEV;
      goto END;
    }
  }

  /* note: we assumed that the BIOS picked SMBus or I2C Bus timing
     appropriately (bit 2 in SMBHSTCFG) */
  /* Everything is happy, let's grab the memory and set things up. */
  request_region(i801_smba, 8, "i801-smbus");       

#ifdef DEBUG
  if (temp & 0x02)
     printk("i2c-i801.o: I801 using Interrupt SMI# for SMBus.\n");
  else 
     printk("i2c-i801.o: I801 using PCI Interrupt for SMBus.\n");

  pci_read_config_byte_united(I801_dev, I801_bus, I801_devfn, SMBREV, 
                              &temp);
  printk("i2c-i801.o: SMBREV = 0x%X\n",temp);
  printk("i2c-i801.o: I801_smba = 0x%X\n",i801_smba);
#endif /* DEBUG */

END:
  return error_return;
}


/* Internally used pause function */
void i801_do_pause( unsigned int amount )
{
      current->state = TASK_INTERRUPTIBLE;
      schedule_timeout(amount);
}

/* Another internally used function */
int i801_transaction(void) 
{
  int temp;
  int result=0;
  int timeout=0;

#ifdef DEBUG
  printk("i2c-i801.o: Transaction (pre): CNT=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, "
         "DAT1=%02x\n",
         inb_p(SMBHSTCNT),inb_p(SMBHSTCMD),inb_p(SMBHSTADD),inb_p(SMBHSTDAT0),
         inb_p(SMBHSTDAT1));
#endif

  /* Make sure the SMBus host is ready to start transmitting */
  /* 0x1f = Failed, Bus_Err, Dev_Err, Intr, Host_Busy */
  if ((temp = (0x1f & inb_p(SMBHSTSTS))) != 0x00) {
#ifdef DEBUG
    printk("i2c-i801.o: SMBus busy (%02x). Resetting... \n",temp);
#endif
    outb_p(temp, SMBHSTSTS);
    if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
#ifdef DEBUG
      printk("i2c-i801.o: Failed! (%02x)\n",temp);
#endif
      return -1;
    } else {
#ifdef DEBUG
      printk("i2c-i801.o: Successfull!\n");
#endif
    }
  }

  /* start the transaction by setting bit 6 */
  outb_p(inb(SMBHSTCNT) | 0x040, SMBHSTCNT); 

  /* We will always wait for a fraction of a second! (See PIIX4 docs errata) */
  do {
    i801_do_pause(1);
    temp=inb_p(SMBHSTSTS);
  } while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));

  /* If the SMBus is still busy, we give up */
  if (timeout >= MAX_TIMEOUT) {
#ifdef DEBUG
    printk("i2c-i801.o: SMBus Timeout!\n"); 
    result = -1;
#endif
  }

  if (temp & 0x10) {
    result = -1;
#ifdef DEBUG
    printk("i2c-i801.o: Error: Failed bus transaction\n");
#endif
  }

  if (temp & 0x08) {
    result = -1;
    printk("i2c-i801.o: Bus collision! SMBus may be locked until next hard
           reset. (sorry!)\n");
    /* Clock stops and slave is stuck in mid-transmission */
  }

  if (temp & 0x04) {
    result = -1;
#ifdef DEBUG
    printk("i2c-i801.o: Error: no response!\n");
#endif
  }

  if ((inb_p(SMBHSTSTS) & 0x1f) != 0x00)
    outb_p( inb(SMBHSTSTS), SMBHSTSTS);

  if ((temp = (0x1f & inb_p(SMBHSTSTS))) != 0x00) {
#ifdef DEBUG
    printk("i2c-i801.o: Failed reset at end of transaction (%02x)\n",temp);
#endif
  }
#ifdef DEBUG
  printk("i2c-i801.o: Transaction (post): CNT=%02x, CMD=%02x, ADD=%02x, "
         "DAT0=%02x, DAT1=%02x\n",
         inb_p(SMBHSTCNT),inb_p(SMBHSTCMD),inb_p(SMBHSTADD),inb_p(SMBHSTDAT0),
         inb_p(SMBHSTDAT1));
#endif
  return result;
}

/* Return -1 on error. See smbus.h for more information */
s32 i801_access(struct i2c_adapter *adap, u8 addr, char read_write,
                 u8 command, int size, union i2c_smbus_data * data)
{
  int i,len;

  switch(size) {
    case I2C_SMBUS_PROC_CALL:
      printk("i2c-i801.o: I2C_SMBUS_PROC_CALL not supported!\n");
      return -1;
    case I2C_SMBUS_QUICK:
      outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD);
      size = I801_QUICK;
      break;
    case I2C_SMBUS_BYTE:
      outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD);
      if (read_write == I2C_SMBUS_WRITE)
        outb_p(command, SMBHSTCMD);
      size = I801_BYTE;
      break;
    case I2C_SMBUS_BYTE_DATA:
      outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD);
      outb_p(command, SMBHSTCMD);
      if (read_write == I2C_SMBUS_WRITE)
        outb_p(data->byte,SMBHSTDAT0);
      size = I801_BYTE_DATA;
      break;
    case I2C_SMBUS_WORD_DATA:
      outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD);
      outb_p(command, SMBHSTCMD);
      if (read_write == I2C_SMBUS_WRITE) {
        outb_p(data->word & 0xff,SMBHSTDAT0);
        outb_p((data->word & 0xff00) >> 8,SMBHSTDAT1);
      }
      size = I801_WORD_DATA;
      break;
    case I2C_SMBUS_BLOCK_DATA:
      outb_p(((addr & 0x7f) << 1) | (read_write & 0x01), SMBHSTADD);
      outb_p(command, SMBHSTCMD);
      if (read_write == I2C_SMBUS_WRITE) {
        len = data->block[0];
        if (len < 0) 
          len = 0;
        if (len > 32)
          len = 32;
        outb_p(len,SMBHSTDAT0);
        i = inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
        for (i = 1; i <= len; i ++)
          outb_p(data->block[i],SMBBLKDAT);
      }
      size = I801_BLOCK_DATA;
      break;
  }

  outb_p((size & 0x1C) + (ENABLE_INT9 & 1), SMBHSTCNT);

  if (i801_transaction()) /* Error in transaction */ 
    return -1; 
  
  if ((read_write == I2C_SMBUS_WRITE) || (size == I801_QUICK))
    return 0;
  

  switch(size) {
    case I801_BYTE: /* Where is the result put? I assume here it is in
                        SMBHSTDAT0 but it might just as well be in the
                        SMBHSTCMD. No clue in the docs */
 
      data->byte = inb_p(SMBHSTDAT0);
      break;
    case I801_BYTE_DATA:
      data->byte = inb_p(SMBHSTDAT0);
      break;
    case I801_WORD_DATA:
      data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
      break;
    case I801_BLOCK_DATA:
      data->block[0] = inb_p(SMBHSTDAT0);
      i = inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
      for (i = 1; i <= data->block[0]; i++)
        data->block[i] = inb_p(SMBBLKDAT);
      break;
  }
  return 0;
}

void i801_inc(struct i2c_adapter *adapter)
{
        MOD_INC_USE_COUNT;
}

void i801_dec(struct i2c_adapter *adapter)
{

        MOD_DEC_USE_COUNT;
}

int __init i2c_i801_init(void)
{
  int res;
  printk("i801.o version %s (%s)\n",LM_VERSION,LM_DATE);
#ifdef DEBUG
/* PE- It might be good to make this a permanent part of the code! */
  if (i801_initialized) {
    printk("i2c-i801.o: Oops, i801_init called a second time!\n");
    return -EBUSY;
  }
#endif
  i801_initialized = 0;
  if ((res = i801_setup())) {
    printk("i2c-i801.o: I801 not detected, module not inserted.\n");
    i801_cleanup();
    return res;
  }
  i801_initialized ++;
  sprintf(i801_adapter.name,"SMBus I801 adapter at %04x",i801_smba);
  if ((res = i2c_add_adapter(&i801_adapter))) {
    printk("i2c-i801.o: Adapter registration failed, module not inserted.\n");
    i801_cleanup();
    return res;
  }
  i801_initialized++;
  printk("i2c-i801.o: I801 bus detected and initialized\n");
  return 0;
}

int __init i801_cleanup(void)
{
  int res;
  if (i801_initialized >= 2)
  {
    if ((res = i2c_del_adapter(&i801_adapter))) {
      printk("i2c-i801.o: i2c_del_adapter failed, module not removed\n");
      return res;
    } else
      i801_initialized--;
  }
  if (i801_initialized >= 1) {
    release_region(i801_smba, 8);
    i801_initialized--;
  }
  return 0;
}

EXPORT_NO_SYMBOLS;

#ifdef MODULE

MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, Philip Edelbrock <phil@netroedge.com>, and Mark D. Studebaker <mds@eng.paradyne.com>");
MODULE_DESCRIPTION("I801 SMBus driver");

int init_module(void)
{
  return i2c_i801_init();
}

int cleanup_module(void)
{
  return i801_cleanup();
}

#endif /* MODULE */