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path: root/drivers/i2c/busses/i2c-i801.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-i801.c')
-rw-r--r--drivers/i2c/busses/i2c-i801.c200
1 files changed, 102 insertions, 98 deletions
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 73bd8552734..46aa41f73fd 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -4,7 +4,7 @@
Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl>,
Philip Edelbrock <phil@netroedge.com>, and Mark D. Studebaker
<mdsxyz123@yahoo.com>
- Copyright (C) 2007 Jean Delvare <khali@linux-fr.org>
+ Copyright (C) 2007, 2008 Jean Delvare <khali@linux-fr.org>
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
@@ -121,6 +121,10 @@
#define SMBHSTSTS_INTR 0x02
#define SMBHSTSTS_HOST_BUSY 0x01
+#define STATUS_FLAGS (SMBHSTSTS_BYTE_DONE | SMBHSTSTS_FAILED | \
+ SMBHSTSTS_BUS_ERR | SMBHSTSTS_DEV_ERR | \
+ SMBHSTSTS_INTR)
+
static unsigned long i801_smba;
static unsigned char i801_original_hstcfg;
static struct pci_driver i801_driver;
@@ -132,72 +136,114 @@ static struct pci_dev *I801_dev;
#define FEATURE_I2C_BLOCK_READ (1 << 3)
static unsigned int i801_features;
-static int i801_transaction(int xact)
+/* Make sure the SMBus host is ready to start transmitting.
+ Return 0 if it is, -EBUSY if it is not. */
+static int i801_check_pre(void)
{
int status;
- int result = 0;
- int timeout = 0;
- /* Make sure the SMBus host is ready to start transmitting */
- /* 0x1f = Failed, Bus_Err, Dev_Err, Intr, Host_Busy */
- if ((status = (0x1f & inb_p(SMBHSTSTS))) != 0x00) {
- dev_dbg(&I801_dev->dev, "SMBus busy (%02x). Resetting...\n",
+ status = inb_p(SMBHSTSTS);
+ if (status & SMBHSTSTS_HOST_BUSY) {
+ dev_err(&I801_dev->dev, "SMBus is busy, can't use it!\n");
+ return -EBUSY;
+ }
+
+ status &= STATUS_FLAGS;
+ if (status) {
+ dev_dbg(&I801_dev->dev, "Clearing status flags (%02x)\n",
status);
outb_p(status, SMBHSTSTS);
- if ((status = (0x1f & inb_p(SMBHSTSTS))) != 0x00) {
- dev_dbg(&I801_dev->dev, "Failed! (%02x)\n", status);
+ status = inb_p(SMBHSTSTS) & STATUS_FLAGS;
+ if (status) {
+ dev_err(&I801_dev->dev,
+ "Failed clearing status flags (%02x)\n",
+ status);
return -EBUSY;
- } else {
- dev_dbg(&I801_dev->dev, "Successful!\n");
}
}
- /* the current contents of SMBHSTCNT can be overwritten, since PEC,
- * INTREN, SMBSCMD are passed in xact */
- outb_p(xact | I801_START, SMBHSTCNT);
+ return 0;
+}
- /* We will always wait for a fraction of a second! */
- do {
- msleep(1);
- status = inb_p(SMBHSTSTS);
- } while ((status & SMBHSTSTS_HOST_BUSY) && (timeout++ < MAX_TIMEOUT));
+/* Convert the status register to an error code, and clear it. */
+static int i801_check_post(int status, int timeout)
+{
+ int result = 0;
/* If the SMBus is still busy, we give up */
- if (timeout >= MAX_TIMEOUT) {
- dev_dbg(&I801_dev->dev, "SMBus Timeout!\n");
- result = -ETIMEDOUT;
+ if (timeout) {
+ dev_err(&I801_dev->dev, "Transaction timeout\n");
/* try to stop the current command */
dev_dbg(&I801_dev->dev, "Terminating the current operation\n");
outb_p(inb_p(SMBHSTCNT) | SMBHSTCNT_KILL, SMBHSTCNT);
msleep(1);
outb_p(inb_p(SMBHSTCNT) & (~SMBHSTCNT_KILL), SMBHSTCNT);
+
+ /* Check if it worked */
+ status = inb_p(SMBHSTSTS);
+ if ((status & SMBHSTSTS_HOST_BUSY) ||
+ !(status & SMBHSTSTS_FAILED))
+ dev_err(&I801_dev->dev,
+ "Failed terminating the transaction\n");
+ outb_p(STATUS_FLAGS, SMBHSTSTS);
+ return -ETIMEDOUT;
}
if (status & SMBHSTSTS_FAILED) {
result = -EIO;
- dev_dbg(&I801_dev->dev, "Error: Failed bus transaction\n");
+ dev_err(&I801_dev->dev, "Transaction failed\n");
+ }
+ if (status & SMBHSTSTS_DEV_ERR) {
+ result = -ENXIO;
+ dev_dbg(&I801_dev->dev, "No response\n");
}
-
if (status & SMBHSTSTS_BUS_ERR) {
result = -EAGAIN;
dev_dbg(&I801_dev->dev, "Lost arbitration\n");
}
- if (status & SMBHSTSTS_DEV_ERR) {
- result = -ENXIO;
- dev_dbg(&I801_dev->dev, "Error: no response!\n");
+ if (result) {
+ /* Clear error flags */
+ outb_p(status & STATUS_FLAGS, SMBHSTSTS);
+ status = inb_p(SMBHSTSTS) & STATUS_FLAGS;
+ if (status) {
+ dev_warn(&I801_dev->dev, "Failed clearing status "
+ "flags at end of transaction (%02x)\n",
+ status);
+ }
}
- if ((inb_p(SMBHSTSTS) & 0x1f) != 0x00)
- outb_p(inb(SMBHSTSTS), SMBHSTSTS);
-
- if ((status = (0x1f & inb_p(SMBHSTSTS))) != 0x00) {
- dev_dbg(&I801_dev->dev, "Failed reset at end of transaction "
- "(%02x)\n", status);
- }
return result;
}
+static int i801_transaction(int xact)
+{
+ int status;
+ int result;
+ int timeout = 0;
+
+ result = i801_check_pre();
+ if (result < 0)
+ return result;
+
+ /* the current contents of SMBHSTCNT can be overwritten, since PEC,
+ * INTREN, SMBSCMD are passed in xact */
+ outb_p(xact | I801_START, SMBHSTCNT);
+
+ /* We will always wait for a fraction of a second! */
+ do {
+ msleep(1);
+ status = inb_p(SMBHSTSTS);
+ } while ((status & SMBHSTSTS_HOST_BUSY) && (timeout++ < MAX_TIMEOUT));
+
+ result = i801_check_post(status, timeout >= MAX_TIMEOUT);
+ if (result < 0)
+ return result;
+
+ outb_p(SMBHSTSTS_INTR, SMBHSTSTS);
+ return 0;
+}
+
/* wait for INTR bit as advised by Intel */
static void i801_wait_hwpec(void)
{
@@ -256,9 +302,12 @@ static int i801_block_transaction_byte_by_byte(union i2c_smbus_data *data,
int i, len;
int smbcmd;
int status;
- int result = 0;
+ int result;
int timeout;
- unsigned char errmask;
+
+ result = i801_check_pre();
+ if (result < 0)
+ return result;
len = data->block[0];
@@ -282,31 +331,6 @@ static int i801_block_transaction_byte_by_byte(union i2c_smbus_data *data,
}
outb_p(smbcmd | ENABLE_INT9, SMBHSTCNT);
- /* Make sure the SMBus host is ready to start transmitting */
- status = inb_p(SMBHSTSTS);
- if (i == 1) {
- /* Erroneous conditions before transaction:
- * Byte_Done, Failed, Bus_Err, Dev_Err, Intr, Host_Busy */
- errmask = 0x9f;
- } else {
- /* Erroneous conditions during transaction:
- * Failed, Bus_Err, Dev_Err, Intr */
- errmask = 0x1e;
- }
- if (status & errmask) {
- dev_dbg(&I801_dev->dev, "SMBus busy (%02x). "
- "Resetting...\n", status);
- outb_p(status, SMBHSTSTS);
- if (((status = inb_p(SMBHSTSTS)) & errmask) != 0x00) {
- dev_err(&I801_dev->dev,
- "Reset failed! (%02x)\n", status);
- return -EBUSY;
- }
- if (i != 1)
- /* if die in middle of block transaction, fail */
- return -EIO;
- }
-
if (i == 1)
outb_p(inb(SMBHSTCNT) | I801_START, SMBHSTCNT);
@@ -319,36 +343,23 @@ static int i801_block_transaction_byte_by_byte(union i2c_smbus_data *data,
while ((!(status & SMBHSTSTS_BYTE_DONE))
&& (timeout++ < MAX_TIMEOUT));
- /* If the SMBus is still busy, we give up */
- if (timeout >= MAX_TIMEOUT) {
- /* try to stop the current command */
- dev_dbg(&I801_dev->dev, "Terminating the current "
- "operation\n");
- outb_p(inb_p(SMBHSTCNT) | SMBHSTCNT_KILL, SMBHSTCNT);
- msleep(1);
- outb_p(inb_p(SMBHSTCNT) & (~SMBHSTCNT_KILL),
- SMBHSTCNT);
- result = -ETIMEDOUT;
- dev_dbg(&I801_dev->dev, "SMBus Timeout!\n");
- }
-
- if (status & SMBHSTSTS_FAILED) {
- result = -EIO;
- dev_dbg(&I801_dev->dev,
- "Error: Failed bus transaction\n");
- } else if (status & SMBHSTSTS_BUS_ERR) {
- result = -EAGAIN;
- dev_dbg(&I801_dev->dev, "Lost arbitration\n");
- } else if (status & SMBHSTSTS_DEV_ERR) {
- result = -ENXIO;
- dev_dbg(&I801_dev->dev, "Error: no response!\n");
- }
+ result = i801_check_post(status, timeout >= MAX_TIMEOUT);
+ if (result < 0)
+ return result;
if (i == 1 && read_write == I2C_SMBUS_READ
&& command != I2C_SMBUS_I2C_BLOCK_DATA) {
len = inb_p(SMBHSTDAT0);
- if (len < 1 || len > I2C_SMBUS_BLOCK_MAX)
+ if (len < 1 || len > I2C_SMBUS_BLOCK_MAX) {
+ dev_err(&I801_dev->dev,
+ "Illegal SMBus block read size %d\n",
+ len);
+ /* Recover */
+ while (inb_p(SMBHSTSTS) & SMBHSTSTS_HOST_BUSY)
+ outb_p(SMBHSTSTS_BYTE_DONE, SMBHSTSTS);
+ outb_p(SMBHSTSTS_INTR, SMBHSTSTS);
return -EPROTO;
+ }
data->block[0] = len;
}
@@ -357,19 +368,12 @@ static int i801_block_transaction_byte_by_byte(union i2c_smbus_data *data,
data->block[i] = inb_p(SMBBLKDAT);
if (read_write == I2C_SMBUS_WRITE && i+1 <= len)
outb_p(data->block[i+1], SMBBLKDAT);
- if ((status & 0x9e) != 0x00)
- outb_p(status, SMBHSTSTS); /* signals SMBBLKDAT ready */
- if ((status = (0x1e & inb_p(SMBHSTSTS))) != 0x00) {
- dev_dbg(&I801_dev->dev,
- "Bad status (%02x) at end of transaction\n",
- status);
- }
-
- if (result < 0)
- return result;
+ /* signals SMBBLKDAT ready */
+ outb_p(SMBHSTSTS_BYTE_DONE | SMBHSTSTS_INTR, SMBHSTSTS);
}
- return result;
+
+ return 0;
}
static int i801_set_block_buffer_mode(void)
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-16 04:38:34 +0000