lm-sensors/kernel/busses/i2c-amd756.c

/*
    amd756.c - Part of lm_sensors, Linux kernel modules for hardware
              monitoring

    Copyright (c) 1999 Merlin Hughes <merlin@merlin.org>

    Shamelessly ripped from i2c-piix4.c:

    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.
*/

/* Note: we assume there can only be one AMD756, with one SMBus interface */

#include <linux/version.h>
#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 <linux/init.h>

/* AMD756 SMBus address offsets */
#define SMB_ADDR_OFFSET        0xE0
#define SMB_IOSIZE             16
#define SMB_GLOBAL_STATUS      (0x0 + amd756_smba)
#define SMB_GLOBAL_ENABLE      (0x2 + amd756_smba)
#define SMB_HOST_ADDRESS       (0x4 + amd756_smba)
#define SMB_HOST_DATA          (0x6 + amd756_smba)
#define SMB_HOST_COMMAND       (0x8 + amd756_smba)
#define SMB_HOST_BLOCK_DATA    (0x9 + amd756_smba)
#define SMB_HAS_DATA           (0xA + amd756_smba)
#define SMB_HAS_DEVICE_ADDRESS (0xC + amd756_smba)
#define SMB_HAS_HOST_ADDRESS   (0xE + amd756_smba)
#define SMB_SNOOP_ADDRESS      (0xF + amd756_smba)

/* PCI Address Constants */

/* address of I/O space */
#define SMBBA     0x058		/* mh */

/* general configuration */
#define SMBGCFG   0x041		/* mh */

/* silicon revision code */
#define SMBREV    0x008

/* Other settings */
#define MAX_TIMEOUT 500

/* AMD756 constants */
#define AMD756_QUICK        0x00
#define AMD756_BYTE         0x01
#define AMD756_BYTE_DATA    0x02
#define AMD756_WORD_DATA    0x03
#define AMD756_PROCESS_CALL 0x04
#define AMD756_BLOCK_DATA   0x05

/* insmod parameters */

#ifdef MODULE
static
#else
extern
#endif
int __init i2c_amd756_init(void);
static int __init amd756_cleanup(void);
static int amd756_setup(void);
static s32 amd756_access(struct i2c_adapter *adap, u16 addr,
			 unsigned short flags, char read_write,
			 u8 command, int size, union i2c_smbus_data *data);
static void amd756_do_pause(unsigned int amount);
static int amd756_transaction(void);
static void amd756_inc(struct i2c_adapter *adapter);
static void amd756_dec(struct i2c_adapter *adapter);
static u32 amd756_func(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 */ amd756_access,
	/* slave_send */ NULL,
	/* slave_rcv */ NULL,
	/* algo_control */ NULL,
	/* functionality */ amd756_func,
};

static struct i2c_adapter amd756_adapter = {
	"unset",
	I2C_ALGO_SMBUS | I2C_HW_SMBUS_AMD756,
	&smbus_algorithm,
	NULL,
	amd756_inc,
	amd756_dec,
	NULL,
	NULL,
};

static int __initdata amd756_initialized;
static unsigned short amd756_smba = 0;

/* externalize it */
#define PCI_DEVICE_ID_AMD_756 0x740B

/* Detect whether a AMD756 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 amd756_setup(void)
{
	int error_return = 0;
	unsigned char temp;

	struct pci_dev *AMD756_dev;

	/* First check whether we can access PCI at all */
	if (pci_present() == 0) {
		printk("i2c-amd756.o: Error: No PCI-bus found!\n");
		error_return = -ENODEV;
		goto END;
	}

	/* Look for the AMD756, function 3 */
	/* Note: we keep on searching until we have found 'function 3' */
	AMD756_dev = NULL;
	do
		AMD756_dev = pci_find_device(PCI_VENDOR_ID_AMD,
					     PCI_DEVICE_ID_AMD_756,
					     AMD756_dev);
	while (AMD756_dev && (PCI_FUNC(AMD756_dev->devfn) != 3));
	if (AMD756_dev == NULL) {
		printk
		    ("i2c-amd756.o: Error: Can't detect AMD756, function 3!\n");
		error_return = -ENODEV;
		goto END;
	}


	pci_read_config_byte(AMD756_dev, SMBGCFG, &temp);
	if ((temp & 128) == 0) {
		printk
		    ("SMBUS: Error: Host SMBus controller I/O not enabled!\n");
		error_return = -ENODEV;
		goto END;
	}

	/* Determine the address of the SMBus areas */
	/* Technically it is a dword but... */
	pci_read_config_word(AMD756_dev, SMBBA, &amd756_smba);
	amd756_smba &= 0xff00;
	amd756_smba += SMB_ADDR_OFFSET;

	if (check_region(amd756_smba, SMB_IOSIZE)) {
		printk
		    ("i2c-amd756.o: AMD756_smb region 0x%x already in use!\n",
		     amd756_smba);
		error_return = -ENODEV;
		goto END;
	}

	/* Everything is happy, let's grab the memory and set things up. */
	request_region(amd756_smba, SMB_IOSIZE, "amd756-smbus");

#ifdef DEBUG
	/*
	   if ((temp & 0x0E) == 8)
	   printk("i2c-amd756.o: AMD756 using Interrupt 9 for SMBus.\n");
	   else if ((temp & 0x0E) == 0)
	   printk("i2c-amd756.o: AMD756 using Interrupt SMI# for SMBus.\n");
	   else 
	   printk("i2c-amd756.o: AMD756: Illegal Interrupt configuration (or code out "
	   "of date)!\n");
	 */

	pci_read_config_byte(AMD756_dev, SMBREV, &temp);
	printk("i2c-amd756.o: SMBREV = 0x%X\n", temp);
	printk("i2c-amd756.o: AMD756_smba = 0x%X\n", amd756_smba);
#endif				/* DEBUG */

      END:
	return error_return;
}

/* 
  SMBUS event = I/O 28-29 bit 11
     see E0 for the status bits and enabled in E2
     
*/

/* Internally used pause function */
void amd756_do_pause(unsigned int amount)
{
	current->state = TASK_INTERRUPTIBLE;
	schedule_timeout(amount);
}

#define GS_ABRT_STS (1 << 0)
#define GS_COL_STS (1 << 1)
#define GS_PRERR_STS (1 << 2)
#define GS_HST_STS (1 << 3)
#define GS_HCYC_STS (1 << 4)
#define GS_TO_STS (1 << 5)

#define GS_CLEAR_STS (GS_ABRT_STS | GS_COL_STS | GS_PRERR_STS | \
  GS_HCYC_STS | GS_TO_STS )

#define GE_CYC_TYPE_MASK (7)
#define GE_HOST_STC (1 << 3)

/* Another internally used function */
int amd756_transaction(void)
{
	int temp;
	int result = 0;
	int timeout = 0;

#ifdef DEBUG
	printk
	    ("i2c-amd756.o: Transaction (pre): GS=%04x, GE=%04x, ADD=%04x, DAT=%04x\n",
	     inw_p(SMB_GLOBAL_STATUS), inw_p(SMB_GLOBAL_ENABLE),
	     inw_p(SMB_HOST_ADDRESS), inb_p(SMB_HOST_DATA));
#endif

	/* Make sure the SMBus host is ready to start transmitting */
	/* TODO: What about SM_BSY? */
	if (((temp = inw_p(SMB_GLOBAL_STATUS)) & GS_HST_STS) != 0x00) {
#ifdef DEBUG
		printk
		    ("i2c-amd756.o: SMBus busy (%04x). Resetting (NOT)... \n",
		     temp);
#endif
		/* TODO: How to reset the AMD?
		   outb_p(temp, SMBHSTSTS);
		 */
		if (((temp = inw_p(SMB_GLOBAL_STATUS)) & GS_HST_STS) !=
		    0x00) {
#ifdef DEBUG
			printk("i2c-amd756.o: Failed! (%04x)\n", temp);
#endif
			return -1;
		} else {
#ifdef DEBUG
			printk("i2c-amd756.o: Successfull!\n");
#endif
		}
	}

	/* start the transaction by setting bit 6 */
	outw_p(inw(SMB_GLOBAL_ENABLE) | GE_HOST_STC, SMB_GLOBAL_ENABLE);

	/* We will always wait for a fraction of a second! */
	do {
		amd756_do_pause(1);
		temp = inw_p(SMB_GLOBAL_STATUS);
	} while ((temp & GS_HST_STS) && (timeout++ < MAX_TIMEOUT));

	/* If the SMBus is still busy, we give up */
	if (timeout >= MAX_TIMEOUT) {
#ifdef DEBUG
		printk("i2c-amd756.o: SMBus explicit timeout!\n");
		result = -1;
#endif
	}

	if (temp & GS_PRERR_STS) {
		result = -1;
#ifdef DEBUG
		printk("i2c-amd756.o: SMBus Protocol error!\n");
#endif
	}

	if (temp & GS_COL_STS) {
		result = -1;
		printk("i2c-amd756.o: SMBus collision!\n");
		/* TODO: Clear Collision Status with a 1 */
	}

	if (temp & GS_TO_STS) {
		result = -1;
#ifdef DEBUG
		printk("i2c-amd756.o: SMBus protocol timeout!\n");
#endif
	}
#ifdef DEBUG
	if (temp & GS_HCYC_STS) {
		printk("i2c-amd756.o: SMBus protocol success!\n");
	}
#endif

	outw_p(GS_CLEAR_STS, SMB_GLOBAL_STATUS);

	if (((temp = inw_p(SMB_GLOBAL_STATUS)) & GS_CLEAR_STS) != 0x00) {
#ifdef DEBUG
		printk
		    ("i2c-amd756.o: Failed reset at end of transaction (%04x)\n",
		     temp);
#endif
	}
#ifdef DEBUG
	printk
	    ("i2c-amd756.o: Transaction (post): GS=%04x, GE=%04x, ADD=%04x, DAT=%04x\n",
	     inw_p(SMB_GLOBAL_STATUS), inw_p(SMB_GLOBAL_ENABLE),
	     inw_p(SMB_HOST_ADDRESS), inb_p(SMB_HOST_DATA));
#endif

	return result;
}

/* Return -1 on error. See smbus.h for more information */
s32 amd756_access(struct i2c_adapter * adap, u16 addr,
		  unsigned short flags, char read_write,
		  u8 command, int size, union i2c_smbus_data * data)
{
	int i, len;

  /** TODO: Should I supporte the 10-bit transfers? */
	switch (size) {
	case I2C_SMBUS_PROC_CALL:
		printk
		    ("i2c-amd756.o: I2C_SMBUS_PROC_CALL not supported!\n");
		/* TODO: Well... It is supported, I'm just not sure what to do here... */
		return -1;
	case I2C_SMBUS_QUICK:
		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
		       SMB_HOST_ADDRESS);
		size = AMD756_QUICK;
		break;
	case I2C_SMBUS_BYTE:
		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
		       SMB_HOST_ADDRESS);
		/* TODO: Why only during write? */
		if (read_write == I2C_SMBUS_WRITE)
			outb_p(command, SMB_HOST_COMMAND);
		size = AMD756_BYTE;
		break;
	case I2C_SMBUS_BYTE_DATA:
		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
		       SMB_HOST_ADDRESS);
		outb_p(command, SMB_HOST_COMMAND);
		if (read_write == I2C_SMBUS_WRITE)
			outw_p(data->byte, SMB_HOST_DATA);
		size = AMD756_BYTE_DATA;
		break;
	case I2C_SMBUS_WORD_DATA:
		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
		       SMB_HOST_ADDRESS);
		outb_p(command, SMB_HOST_COMMAND);
		if (read_write == I2C_SMBUS_WRITE)
			outw_p(data->word, SMB_HOST_DATA);	/* TODO: endian???? */
		size = AMD756_WORD_DATA;
		break;
	case I2C_SMBUS_BLOCK_DATA:
		outw_p(((addr & 0x7f) << 1) | (read_write & 0x01),
		       SMB_HOST_ADDRESS);
		outb_p(command, SMB_HOST_COMMAND);
		if (read_write == I2C_SMBUS_WRITE) {
			len = data->block[0];
			if (len < 0)
				len = 0;
			if (len > 32)
				len = 32;
			outw_p(len, SMB_HOST_DATA);
			/* i = inw_p(SMBHSTCNT); Reset SMBBLKDAT */
			for (i = 1; i <= len; i++)
				outb_p(data->block[i],
				       SMB_HOST_BLOCK_DATA);
		}
		size = AMD756_BLOCK_DATA;
		break;
	}

	/* How about enabling interrupts... */
	outw_p(size & GE_CYC_TYPE_MASK, SMB_GLOBAL_ENABLE);

	if (amd756_transaction())	/* Error in transaction */
		return -1;

	if ((read_write == I2C_SMBUS_WRITE) || (size == AMD756_QUICK))
		return 0;


	switch (size) {
	case AMD756_BYTE:
		data->byte = inw_p(SMB_HOST_DATA);
		break;
	case AMD756_BYTE_DATA:
		data->byte = inw_p(SMB_HOST_DATA);
		break;
	case AMD756_WORD_DATA:
		data->word = inw_p(SMB_HOST_DATA);	/* TODO: endian???? */
		break;
	case AMD756_BLOCK_DATA:
		data->block[0] = inw_p(SMB_HOST_DATA & 63);
		/* i = inw_p(SMBHSTCNT); Reset SMBBLKDAT */
		for (i = 1; i <= data->block[0]; i++)
			data->block[i] = inb_p(SMB_HOST_BLOCK_DATA);
		break;
	}

	return 0;
}

void amd756_inc(struct i2c_adapter *adapter)
{
	MOD_INC_USE_COUNT;
}

void amd756_dec(struct i2c_adapter *adapter)
{

	MOD_DEC_USE_COUNT;
}

u32 amd756_func(struct i2c_adapter *adapter)
{
	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
	    I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
	    I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL;
}

int __init i2c_amd756_init(void)
{
	int res;
	printk("amd756.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 (amd756_initialized) {
		printk
		    ("i2c-amd756.o: Oops, amd756_init called a second time!\n");
		return -EBUSY;
	}
#endif
	amd756_initialized = 0;
	if ((res = amd756_setup())) {
		printk
		    ("i2c-amd756.o: AMD756 not detected, module not inserted.\n");
		amd756_cleanup();
		return res;
	}
	amd756_initialized++;
	sprintf(amd756_adapter.name, "SMBus AMD756 adapter at %04x",
		amd756_smba);
	if ((res = i2c_add_adapter(&amd756_adapter))) {
		printk
		    ("i2c-amd756.o: Adapter registration failed, module not inserted.\n");
		amd756_cleanup();
		return res;
	}
	amd756_initialized++;
	printk("i2c-amd756.o: AMD756 bus detected and initialized\n");
	return 0;
}

int __init amd756_cleanup(void)
{
	int res;
	if (amd756_initialized >= 2) {
		if ((res = i2c_del_adapter(&amd756_adapter))) {
			printk
			    ("i2c-amd756.o: i2c_del_adapter failed, module not removed\n");
			return res;
		} else
			amd756_initialized--;
	}
	if (amd756_initialized >= 1) {
		release_region(amd756_smba, SMB_IOSIZE);
		amd756_initialized--;
	}
	return 0;
}

EXPORT_NO_SYMBOLS;

#ifdef MODULE

MODULE_AUTHOR("Merlin Hughes <merlin@merlin.org>");
MODULE_DESCRIPTION("AMD756 SMBus driver");

int init_module(void)
{
	return i2c_amd756_init();
}

int cleanup_module(void)
{
	return amd756_cleanup();
}

#endif				/* MODULE */