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[PATCH] i2c-viapro: Code cleanups
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Cleanups to the i2c-viapro driver:
* Kill unused defines.
* Kill interrupt-related code, as the driver doesn't use interrupts.
* Fix broken comments (some copied from i2c-piix4.)
* Centralize the unsupported command error case in vt596_access.
  That way we'll catch all unsupported commands, not only
  I2C_SMBUS_PROC_CALL.
* Refactor some code.
* Convert some dev_dbg into dev_err. Errors better be reported even in
  non-debug mode.
* Do not verify that the final reset succeeded. It'll be checked at
  the beginning of the next transaction anyway.
* Use the driver name to reserve the I/O region.
* Do not print the contents of the SMBREV register, it reads 0 on all
  chips I've seen so far.
* Some other minor fixes all over the place.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

 drivers/i2c/busses/i2c-viapro.c |  122 +++++++++++++---------------------------
 1 file changed, 41 insertions(+), 81 deletions(-)
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Jean Delvare authored and Greg Kroah-Hartman committed Oct 28, 2005
1 parent f118301 commit c2f559d
Showing 1 changed file with 41 additions and 81 deletions.
122 changes: 41 additions & 81 deletions drivers/i2c/busses/i2c-viapro.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -39,7 +39,6 @@
#include <linux/pci.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>
Expand All @@ -54,34 +53,22 @@ static struct pci_dev *vt596_pdev;
/* SMBus address offsets */
static unsigned short vt596_smba;
#define SMBHSTSTS (vt596_smba + 0)
#define SMBHSLVSTS (vt596_smba + 1)
#define SMBHSTCNT (vt596_smba + 2)
#define SMBHSTCMD (vt596_smba + 3)
#define SMBHSTADD (vt596_smba + 4)
#define SMBHSTDAT0 (vt596_smba + 5)
#define SMBHSTDAT1 (vt596_smba + 6)
#define SMBBLKDAT (vt596_smba + 7)
#define SMBSLVCNT (vt596_smba + 8)
#define SMBSHDWCMD (vt596_smba + 9)
#define SMBSLVEVT (vt596_smba + 0xA)
#define SMBSLVDAT (vt596_smba + 0xC)

/* PCI Address Constants */

/* SMBus data in configuration space can be found in two places,
We try to select the better one */

static unsigned short smb_cf_hstcfg = 0xD2;

#define SMBHSTCFG (smb_cf_hstcfg)
#define SMBSLVC (smb_cf_hstcfg + 1)
#define SMBSHDW1 (smb_cf_hstcfg + 2)
#define SMBSHDW2 (smb_cf_hstcfg + 3)
#define SMBREV (smb_cf_hstcfg + 4)
static unsigned short SMBHSTCFG = 0xD2;

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

/* VT82C596 constants */
#define VT596_QUICK 0x00
Expand All @@ -107,12 +94,13 @@ MODULE_PARM_DESC(force_addr,
"EXTREMELY DANGEROUS!");


static struct pci_driver vt596_driver;
static struct i2c_adapter vt596_adapter;

#define FEATURE_I2CBLOCK (1<<0)
static unsigned int vt596_features;

/* Another internally used function */
/* Return -1 on error, 0 on success */
static int vt596_transaction(void)
{
int temp;
Expand All @@ -127,23 +115,21 @@ static int vt596_transaction(void)
/* Make sure the SMBus host is ready to start transmitting */
if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
dev_dbg(&vt596_adapter.dev, "SMBus busy (0x%02x). "
"Resetting...\n", temp);
"Resetting... ", temp);

outb_p(temp, SMBHSTSTS);
if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
dev_dbg(&vt596_adapter.dev, "Failed! (0x%02x)\n", temp);

printk("Failed! (0x%02x)\n", temp);
return -1;
} else {
dev_dbg(&vt596_adapter.dev, "Successfull!\n");
printk("Successful!\n");
}
}

/* start the transaction by setting bit 6 */
outb_p(inb(SMBHSTCNT) | 0x040, SMBHSTCNT);
/* Start the transaction by setting bit 6 */
outb_p(inb(SMBHSTCNT) | 0x40, SMBHSTCNT);

/* We will always wait for a fraction of a second!
I don't know if VIA needs this, Intel did */
/* We will always wait for a fraction of a second */
do {
msleep(1);
temp = inb_p(SMBHSTSTS);
Expand All @@ -152,33 +138,32 @@ static int vt596_transaction(void)
/* If the SMBus is still busy, we give up */
if (timeout >= MAX_TIMEOUT) {
result = -1;
dev_dbg(&vt596_adapter.dev, "SMBus Timeout!\n");
dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
}

if (temp & 0x10) {
result = -1;
dev_dbg(&vt596_adapter.dev, "Error: Failed bus transaction\n");
dev_err(&vt596_adapter.dev, "Transaction failed (0x%02x)\n",
inb_p(SMBHSTCNT) & 0x3C);
}

if (temp & 0x08) {
result = -1;
dev_info(&vt596_adapter.dev, "Bus collision! SMBus may be "
"locked until next hard\nreset. (sorry!)\n");
/* Clock stops and slave is stuck in mid-transmission */
dev_err(&vt596_adapter.dev, "SMBus collision!\n");
}

if (temp & 0x04) {
result = -1;
dev_dbg(&vt596_adapter.dev, "Error: no response!\n");
/* Quick commands are used to probe for chips, so
errors are expected, and we don't want to frighten the
user. */
if ((inb_p(SMBHSTCNT) & 0x3C) != VT596_QUICK)
dev_err(&vt596_adapter.dev, "Transaction error!\n");
}

if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
/* Resetting status register */
if (temp & 0x1F)
outb_p(temp, SMBHSTSTS);
if ((temp = inb_p(SMBHSTSTS)) & 0x1F) {
dev_warn(&vt596_adapter.dev, "Failed reset at end "
"of transaction (%02x)\n", temp);
}
}

dev_dbg(&vt596_adapter.dev, "Transaction (post): CNT=%02x, CMD=%02x, "
"ADD=%02x, DAT0=%02x, DAT1=%02x\n", inb_p(SMBHSTCNT),
Expand All @@ -188,41 +173,29 @@ static int vt596_transaction(void)
return result;
}

/* Return -1 on error. */
/* Return -1 on error, 0 on success */
static s32 vt596_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;
int i;

switch (size) {
case I2C_SMBUS_PROC_CALL:
dev_info(&vt596_adapter.dev,
"I2C_SMBUS_PROC_CALL not supported!\n");
return -1;
case I2C_SMBUS_QUICK:
outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
SMBHSTADD);
size = VT596_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 = VT596_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 = VT596_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);
Expand All @@ -232,31 +205,30 @@ static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
if (!(vt596_features & FEATURE_I2CBLOCK))
return -1;
goto exit_unsupported;
if (read_write == I2C_SMBUS_READ)
outb_p(I2C_SMBUS_BLOCK_MAX, SMBHSTDAT0);
/* Fall through */
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;
u8 len = data->block[0];
if (len > I2C_SMBUS_BLOCK_MAX)
len = I2C_SMBUS_BLOCK_MAX;
outb_p(len, SMBHSTDAT0);
i = inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
for (i = 1; i <= len; i++)
outb_p(data->block[i], SMBBLKDAT);
}
size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
break;
default:
goto exit_unsupported;
}

outb_p((size & 0x3C) + (ENABLE_INT9 & 1), SMBHSTCNT);
outb_p(((addr & 0x7f) << 1) | read_write, SMBHSTADD);
outb_p((size & 0x3C), SMBHSTCNT);

if (vt596_transaction()) /* Error in transaction */
return -1;
Expand All @@ -266,12 +238,6 @@ static s32 vt596_access(struct i2c_adapter *adap, u16 addr,

switch (size) {
case VT596_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 VT596_BYTE_DATA:
data->byte = inb_p(SMBHSTDAT0);
break;
Expand All @@ -283,12 +249,17 @@ static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
data->block[0] = inb_p(SMBHSTDAT0);
if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
data->block[0] = I2C_SMBUS_BLOCK_MAX;
i = inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
inb_p(SMBHSTCNT); /* Reset SMBBLKDAT */
for (i = 1; i <= data->block[0]; i++)
data->block[i] = inb_p(SMBBLKDAT);
break;
}
return 0;

exit_unsupported:
dev_warn(&vt596_adapter.dev, "Unsupported command invoked! (0x%02x)\n",
size);
return -1;
}

static u32 vt596_func(struct i2c_adapter *adapter)
Expand All @@ -311,7 +282,6 @@ static struct i2c_adapter vt596_adapter = {
.owner = THIS_MODULE,
.class = I2C_CLASS_HWMON,
.algo = &smbus_algorithm,
.name = "unset",
};

static int __devinit vt596_probe(struct pci_dev *pdev,
Expand All @@ -328,12 +298,12 @@ static int __devinit vt596_probe(struct pci_dev *pdev,
}

if ((pci_read_config_word(pdev, id->driver_data, &vt596_smba)) ||
!(vt596_smba & 0x1)) {
!(vt596_smba & 0x0001)) {
/* try 2nd address and config reg. for 596 */
if (id->device == PCI_DEVICE_ID_VIA_82C596_3 &&
!pci_read_config_word(pdev, SMBBA2, &vt596_smba) &&
(vt596_smba & 0x1)) {
smb_cf_hstcfg = 0x84;
(vt596_smba & 0x0001)) {
SMBHSTCFG = 0x84;
} else {
/* no matches at all */
dev_err(&pdev->dev, "Cannot configure "
Expand All @@ -351,7 +321,7 @@ static int __devinit vt596_probe(struct pci_dev *pdev,
}

found:
if (!request_region(vt596_smba, 8, "viapro-smbus")) {
if (!request_region(vt596_smba, 8, vt596_driver.name)) {
dev_err(&pdev->dev, "SMBus region 0x%x already in use!\n",
vt596_smba);
return -ENODEV;
Expand All @@ -366,15 +336,15 @@ static int __devinit vt596_probe(struct pci_dev *pdev,
pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
dev_warn(&pdev->dev, "WARNING: SMBus interface set to new "
"address 0x%04x!\n", vt596_smba);
} else if ((temp & 1) == 0) {
} else if (!(temp & 0x01)) {
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(pdev, SMBHSTCFG, temp | 1);
pci_write_config_byte(pdev, SMBHSTCFG, temp | 0x01);
dev_info(&pdev->dev, "Enabling SMBus device\n");
} else {
dev_err(&pdev->dev, "SMBUS: Error: Host SMBus "
Expand All @@ -384,16 +354,6 @@ static int __devinit vt596_probe(struct pci_dev *pdev,
}
}

if ((temp & 0x0E) == 8)
dev_dbg(&pdev->dev, "using Interrupt 9 for SMBus.\n");
else if ((temp & 0x0E) == 0)
dev_dbg(&pdev->dev, "using Interrupt SMI# for SMBus.\n");
else
dev_dbg(&pdev->dev, "Illegal Interrupt configuration "
"(or code out of date)!\n");

pci_read_config_byte(pdev, SMBREV, &temp);
dev_dbg(&pdev->dev, "SMBREV = 0x%X\n", temp);
dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);

switch (pdev->device) {
Expand Down

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