[PATCH] i2c-viapro: Code cleanups

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(-)

diff --git a/drivers/i2c/busses/i2c-viapro.c b/drivers/i2c/busses/i2c-viapro.c
index b420e752b1dc4f9a22ce2bb37f76d43815ad941a..5cf8fe182806173c5fb27599759752a467e7283e 100644 (file)
--- a/drivers/i2c/busses/i2c-viapro.c
+++ b/drivers/i2c/busses/i2c-viapro.c
@@ -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>
@@ -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
@@ -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;
@@ -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);
@@ -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),
@@ -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);
@@ -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;
@@ -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;
@@ -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)
@@ -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,
@@ -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 "
@@ -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;
@@ -366,7 +336,7 @@ found:
                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
@@ -374,7 +344,7 @@ found:
                         * :') 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 "
@@ -384,16 +354,6 @@ found:
                }
        }
 
-       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) {