i2c-nforce2: Move status checking to a separate function
This is the first part of the patch that adds a function to reset the
nvidia MCP51/55 i2c controller, if something bad happens to it (e.g.
a slave sends a wrong byte count during a block transaction).
This patch just adds nforce2_check_status function. It was originally
written by Hans-Frieder Vogt.
The reason that I'm the one sending it is:
- I relied on it for the second part of the patch,
- It makes the driver code cleaner/better.
Signed-off-by: Oleg Ryjkov <olegr@olegr.ca>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/i2c/busses/i2c-nforce2.c b/drivers/i2c/busses/i2c-nforce2.c
index c48140f..1c63c4f 100644
--- a/drivers/i2c/busses/i2c-nforce2.c
+++ b/drivers/i2c/busses/i2c-nforce2.c
@@ -98,15 +98,40 @@
#define NVIDIA_SMB_PRTCL_BLOCK_DATA 0x0a
#define NVIDIA_SMB_PRTCL_PEC 0x80
+/* Misc definitions */
+#define MAX_TIMEOUT 100
+
static struct pci_driver nforce2_driver;
+static int nforce2_check_status(struct i2c_adapter *adap)
+{
+ struct nforce2_smbus *smbus = adap->algo_data;
+ int timeout = 0;
+ unsigned char temp;
+
+ do {
+ msleep(1);
+ temp = inb_p(NVIDIA_SMB_STS);
+ } while ((!temp) && (timeout++ < MAX_TIMEOUT));
+
+ if (timeout >= MAX_TIMEOUT) {
+ dev_dbg(&adap->dev, "SMBus Timeout!\n");
+ return -1;
+ }
+ if (!(temp & NVIDIA_SMB_STS_DONE) || (temp & NVIDIA_SMB_STS_STATUS)) {
+ dev_dbg(&adap->dev, "Transaction failed (0x%02x)!\n", temp);
+ return -1;
+ }
+ return 0;
+}
+
/* Return -1 on error */
static s32 nforce2_access(struct i2c_adapter * adap, u16 addr,
unsigned short flags, char read_write,
u8 command, int size, union i2c_smbus_data * data)
{
struct nforce2_smbus *smbus = adap->algo_data;
- unsigned char protocol, pec, temp;
+ unsigned char protocol, pec;
u8 len;
int i;
@@ -170,21 +195,8 @@
outb_p((addr & 0x7f) << 1, NVIDIA_SMB_ADDR);
outb_p(protocol, NVIDIA_SMB_PRTCL);
- temp = inb_p(NVIDIA_SMB_STS);
-
- if (~temp & NVIDIA_SMB_STS_DONE) {
- udelay(500);
- temp = inb_p(NVIDIA_SMB_STS);
- }
- if (~temp & NVIDIA_SMB_STS_DONE) {
- msleep(10);
- temp = inb_p(NVIDIA_SMB_STS);
- }
-
- if ((~temp & NVIDIA_SMB_STS_DONE) || (temp & NVIDIA_SMB_STS_STATUS)) {
- dev_dbg(&adap->dev, "SMBus Timeout! (0x%02x)\n", temp);
+ if (nforce2_check_status(adap))
return -1;
- }
if (read_write == I2C_SMBUS_WRITE)
return 0;
@@ -202,7 +214,12 @@
case I2C_SMBUS_BLOCK_DATA:
len = inb_p(NVIDIA_SMB_BCNT);
- len = min_t(u8, len, I2C_SMBUS_BLOCK_MAX);
+ if ((len <= 0) || (len > I2C_SMBUS_BLOCK_MAX)) {
+ dev_err(&adap->dev, "Transaction failed "
+ "(received block size: 0x%02x)\n",
+ len);
+ return -1;
+ }
for (i = 0; i < len; i++)
data->block[i+1] = inb_p(NVIDIA_SMB_DATA + i);
data->block[0] = len;