lm-sensors/kernel/busses/i2c-osb4.c

/*
    i2c-osb4.c - Part of lm_sensors, Linux kernel modules for hardware monitoring

    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 was partly written by Steffen Persvold (sp@scali.com)
    for ServerWorks OSB4 southbridge.

*/

/* Note: we assume there can only be one OSB4, 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 <linux/init.h>
#include "version.h"

#ifndef PCI_DEVICE_ID_SERVERWORKS_OSB4
#define PCI_DEVICE_ID_SERVERWORKS_OSB4 0x0200
#endif

#ifndef PCI_VENDOR_ID_SERVERWORKS
#define PCI_VENDOR_ID_SERVERWORKS 0x01166
#endif

/* OSB4 SMBus address offsets */
#define SMBHSTSTS (0 + osb4_smba)
#define SMBHSLVSTS (1 + osb4_smba)
#define SMBHSTCNT (2 + osb4_smba)
#define SMBHSTCMD (3 + osb4_smba)
#define SMBHSTADD (4 + osb4_smba)
#define SMBHSTDAT0 (5 + osb4_smba)
#define SMBHSTDAT1 (6 + osb4_smba)
#define SMBBLKDAT (7 + osb4_smba)
#define SMBSLVCNT (8 + osb4_smba)
#define SMBSHDWCMD (9 + osb4_smba)
#define SMBSLVEVT (0xA + osb4_smba)
#define SMBSLVDAT (0xC + osb4_smba)

/* PCI Address Constants */
#define SMBBA     0x090
#define SMBHSTCFG 0x0D2
#define SMBSLVC   0x0D3
#define SMBSHDW1  0x0D4
#define SMBSHDW2  0x0D5
#define SMBREV    0x0D6

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

/* OSB4 constants */
#define OSB4_QUICK      0x00
#define OSB4_BYTE       0x04
#define OSB4_BYTE_DATA  0x08
#define OSB4_WORD_DATA  0x0C
#define OSB4_BLOCK_DATA 0x14

/* insmod parameters */

/* If force is set to anything different from 0, we forcibly enable the
   OSB4. DANGEROUS! */
static int force = 0;
MODULE_PARM(force, "i");
MODULE_PARM_DESC(force, "Forcibly enable the OSB4. DANGEROUS!");

/* If force_addr is set to anything different from 0, we forcibly enable
   the OSB4 at the given address. VERY DANGEROUS! */
static int force_addr = 0;
MODULE_PARM(force_addr, "i");
MODULE_PARM_DESC(force_addr,
		 "Forcibly enable the OSB4 at the given address. "
		 "EXTREMELY DANGEROUS!");

#ifdef MODULE
static
#else
extern
#endif
int __init i2c_osb4_init(void);
static int __init osb4_cleanup(void);
static int osb4_setup(void);
static s32 osb4_access(struct i2c_adapter *adap, u16 addr,
			unsigned short flags, char read_write,
			u8 command, int size, union i2c_smbus_data *data);
static void osb4_do_pause(unsigned int amount);
static int osb4_transaction(void);
static void osb4_inc(struct i2c_adapter *adapter);
static void osb4_dec(struct i2c_adapter *adapter);
static u32 osb4_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 */ osb4_access,
	/* slave_send */ NULL,
	/* slave_rcv */ NULL,
	/* algo_control */ NULL,
	/* functionality */ osb4_func,
};

static struct i2c_adapter osb4_adapter = {
	"unset",
	I2C_ALGO_SMBUS | I2C_HW_SMBUS_OSB4,
	&smbus_algorithm,
	NULL,
	osb4_inc,
	osb4_dec,
	NULL,
	NULL,
};

static int __initdata osb4_initialized;
static unsigned short osb4_smba = 0;


/* Detect whether a OSB4 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 osb4_setup(void)
{
	int error_return = 0;
	unsigned char temp;

	struct pci_dev *OSB4_dev;

	/* First check whether we can access PCI at all */
	if (pci_present() == 0) {
		printk("i2c-osb4.o: Error: No PCI-bus found!\n");
		error_return = -ENODEV;
		goto END;
	}

	/* Look for the OSB4, function 0 */
	/* Note: we keep on searching until we have found 'function 0' */
	OSB4_dev = NULL;
	do
		OSB4_dev = pci_find_device(PCI_VENDOR_ID_SERVERWORKS,
					    PCI_DEVICE_ID_SERVERWORKS_OSB4,
					    OSB4_dev);
	while (OSB4_dev && (PCI_FUNC(OSB4_dev->devfn) != 0));
	if (OSB4_dev == NULL) {
		printk
		    ("i2c-osb4.o: Error: Can't detect OSB4, function 0!\n");
		error_return = -ENODEV;
		goto END;
	}

        /* Determine the address of the SMBus areas */
	if (force_addr) {
		osb4_smba = force_addr & 0xfff0;
		force = 0;
	} else {

		pci_read_config_word(OSB4_dev, SMBBA, &osb4_smba);
		osb4_smba &= 0xfff0;
	}

	if (check_region(osb4_smba, 8)) {
		printk
		    ("i2c-osb4.o: OSB4_smb region 0x%x already in use!\n",
		     osb4_smba);
		error_return = -ENODEV;
		goto END;
	}

	pci_read_config_byte(OSB4_dev, SMBHSTCFG, &temp);
        /* If force_addr is set, we program the new address here. Just to make
	   sure, we disable the OSB4 first. */
	if (force_addr) {
		pci_write_config_byte(OSB4_dev, SMBHSTCFG, temp & 0xfe);
		pci_write_config_word(OSB4_dev, SMBBA, osb4_smba);
		pci_write_config_byte(OSB4_dev, SMBHSTCFG, temp | 0x01);
		printk
		    ("i2c-osb4.o: WARNING: OSB4 SMBus interface set to new "
		     "address %04x!\n", osb4_smba);
	} else if ((temp & 1) == 0) {
		if (force) {
                        /* 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(OSB4_dev, SMBHSTCFG,
					      temp | 1);
			printk
			    ("i2c-osb4.o: WARNING: OSB4 SMBus interface has been FORCEFULLY "
			     "ENABLED!\n");
		} else {
			printk
			    ("SMBUS: Error: Host SMBus controller not enabled!\n");
			error_return = -ENODEV;
			goto END;
		}
	}

	/* Everything is happy, let's grab the memory and set things up. */
	request_region(osb4_smba, 8, "osb4-smbus");

#ifdef DEBUG
	if ((temp & 0x0E) == 8)
		printk
		    ("i2c-osb4.o: OSB4 using Interrupt 9 for SMBus.\n");
	else if ((temp & 0x0E) == 0)
		printk
		    ("i2c-osb4.o: OSB4 using Interrupt SMI# for SMBus.\n");
	else
		printk
		    ("i2c-osb4.o: OSB4: Illegal Interrupt configuration (or code out "
		     "of date)!\n");

	pci_read_config_byte(OSB4_dev, SMBREV, &temp);
	printk("i2c-osb4.o: SMBREV = 0x%X\n", temp);
	printk("i2c-osb4.o: OSB4_smba = 0x%X\n", osb4_smba);
#endif				/* DEBUG */

      END:
	return error_return;
}


/* Internally used pause function */
void osb4_do_pause(unsigned int amount)
{
	current->state = TASK_INTERRUPTIBLE;
	schedule_timeout(amount);
}

/* Another internally used function */
int osb4_transaction(void)
{
	int temp;
	int result = 0;
	int timeout = 0;

#ifdef DEBUG
	printk
	    ("i2c-osb4.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 */
	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
#ifdef DEBUG
		printk("i2c-osb4.o: SMBus busy (%02x). Resetting... \n",
		       temp);
#endif
		outb_p(temp, SMBHSTSTS);
		if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
#ifdef DEBUG
			printk("i2c-osb4.o: Failed! (%02x)\n", temp);
#endif
			return -1;
		} else {
#ifdef DEBUG
			printk("i2c-osb4.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 OSB4 docs errata) */
	do {
		osb4_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-osb4.o: SMBus Timeout!\n");
		result = -1;
#endif
	}

	if (temp & 0x10) {
		result = -1;
#ifdef DEBUG
		printk("i2c-osb4.o: Error: Failed bus transaction\n");
#endif
	}

	if (temp & 0x08) {
		result = -1;
		printk
		    ("i2c-osb4.o: Bus collision! SMBus may be locked until next hard\n"
		     "reset. (sorry!)\n");
		/* Clock stops and slave is stuck in mid-transmission */
	}

	if (temp & 0x04) {
		result = -1;
#ifdef DEBUG
		printk("i2c-osb4.o: Error: no response!\n");
#endif
	}

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

	if ((temp = inb_p(SMBHSTSTS)) != 0x00) {
#ifdef DEBUG
		printk
		    ("i2c-osb4.o: Failed reset at end of transaction (%02x)\n",
		     temp);
#endif
	}
#ifdef DEBUG
	printk
	    ("i2c-osb4.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 osb4_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;

	switch (size) {
	case I2C_SMBUS_PROC_CALL:
		printk
		    ("i2c-osb4.o: I2C_SMBUS_PROC_CALL not supported!\n");
		return -1;
	case I2C_SMBUS_QUICK:
		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
		       SMBHSTADD);
		size = OSB4_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 = OSB4_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 = OSB4_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 = OSB4_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 = OSB4_BLOCK_DATA;
		break;
	}

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

	if (osb4_transaction())	/* Error in transaction */
		return -1;

	if ((read_write == I2C_SMBUS_WRITE) || (size == OSB4_QUICK))
		return 0;


	switch (size) {
	case OSB4_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 OSB4_BYTE_DATA:
		data->byte = inb_p(SMBHSTDAT0);
		break;
	case OSB4_WORD_DATA:
		data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
		break;
	case OSB4_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 osb4_inc(struct i2c_adapter *adapter)
{
	MOD_INC_USE_COUNT;
}

void osb4_dec(struct i2c_adapter *adapter)
{

	MOD_DEC_USE_COUNT;
}

u32 osb4_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;
}

int __init i2c_osb4_init(void)
{
	int res;
	printk("i2c-osb4.o version %s (%s)\n", LM_VERSION, LM_DATE);
	if (osb4_initialized) {
		printk
		    ("i2c-osb4.o: Oops, osb4_init called a second time!\n");
		return -EBUSY;
	}
	osb4_initialized = 0;
	if ((res = osb4_setup())) {
		printk
		    ("i2c-osb4.o: OSB4 not detected, module not inserted.\n");
		osb4_cleanup();
		return res;
	}
	osb4_initialized++;
	sprintf(osb4_adapter.name, "SMBus OSB4 adapter at %04x",
		osb4_smba);
	if ((res = i2c_add_adapter(&osb4_adapter))) {
		printk
		    ("i2c-osb4.o: Adapter registration failed, module not inserted.\n");
		osb4_cleanup();
		return res;
	}
	osb4_initialized++;
	printk("i2c-osb4.o: OSB4 bus detected and initialized\n");
	return 0;
}

int __init osb4_cleanup(void)
{
	int res;
	if (osb4_initialized >= 2) {
		if ((res = i2c_del_adapter(&osb4_adapter))) {
			printk
			    ("i2c-osb4.o: i2c_del_adapter failed, module not removed\n");
			return res;
		} else
			osb4_initialized--;
	}
	if (osb4_initialized >= 1) {
		release_region(osb4_smba, 8);
		osb4_initialized--;
	}
	return 0;
}

EXPORT_NO_SYMBOLS;

#ifdef MODULE

MODULE_AUTHOR("Steffen Persvold <sp@scali.no>, Philip Edelbrock <phil@netroedge.com>, and Frodo Looijaard <frodol@dds.nl>");
MODULE_DESCRIPTION("ServerWorks OSB4 SMBus driver");

int init_module(void)
{
	return i2c_osb4_init();
}

int cleanup_module(void)
{
	return osb4_cleanup();
}

#endif				/* MODULE */