diff options
| author | Oleg Ryjkov <olegr@olegr.ca> | 2007-10-13 23:56:33 +0200 |
|---|---|---|
| committer | Jean Delvare <khali@hyperion.delvare> | 2007-10-13 23:56:33 +0200 |
| commit | d49584c4a37c7228e7778bcb60f79e7a08472fa8 (patch) | |
| tree | 73d1d9e7c65d64d2f4cbe0f9fae4f97494df5006 /drivers/i2c | |
| parent | i2c-nforce2: Move status checking to a separate function (diff) | |
| download | linux-d49584c4a37c7228e7778bcb60f79e7a08472fa8.tar.xz linux-d49584c4a37c7228e7778bcb60f79e7a08472fa8.zip | |
i2c-nforce2: Abort the transaction on error
This patch is to add an abort function that will bring back the MCP51/55
controller if it was blocked by a block-read operation, in particular.
(When a slave sends a wrong byte count on a byte read, the host gets
locked up). I've only tested it on an MCP51 and MCP55. However, I'm
almost certain it will also work on MCP65, I just did not have the board
to test it on. Thus for now the abort function will only be called
if an MCP51/55 was detected.
Signed-off-by: Oleg Ryjkov <olegr@olegr.ca>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-nforce2.c | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-nforce2.c b/drivers/i2c/busses/i2c-nforce2.c index 1c63c4f2e4b6..c359eabe85fb 100644 --- a/drivers/i2c/busses/i2c-nforce2.c +++ b/drivers/i2c/busses/i2c-nforce2.c @@ -62,6 +62,7 @@ struct nforce2_smbus { int base; int size; int blockops; + int can_abort; }; @@ -83,7 +84,14 @@ struct nforce2_smbus { #define NVIDIA_SMB_DATA (smbus->base + 0x04) /* 32 data registers */ #define NVIDIA_SMB_BCNT (smbus->base + 0x24) /* number of data bytes */ - +#define NVIDIA_SMB_STATUS_ABRT (smbus->base + 0x3c) /* register used to + check the status of + the abort command */ +#define NVIDIA_SMB_CTRL (smbus->base + 0x3e) /* control register */ + +#define NVIDIA_SMB_STATUS_ABRT_STS 0x01 /* Bit to notify that + abort succeeded */ +#define NVIDIA_SMB_CTRL_ABORT 0x20 #define NVIDIA_SMB_STS_DONE 0x80 #define NVIDIA_SMB_STS_ALRM 0x40 #define NVIDIA_SMB_STS_RES 0x20 @@ -103,6 +111,25 @@ struct nforce2_smbus { static struct pci_driver nforce2_driver; +static void nforce2_abort(struct i2c_adapter *adap) +{ + struct nforce2_smbus *smbus = adap->algo_data; + int timeout = 0; + unsigned char temp; + + dev_dbg(&adap->dev, "Aborting current transaction\n"); + + outb_p(NVIDIA_SMB_CTRL_ABORT, NVIDIA_SMB_CTRL); + do { + msleep(1); + temp = inb_p(NVIDIA_SMB_STATUS_ABRT); + } while (!(temp & NVIDIA_SMB_STATUS_ABRT_STS) && + (timeout++ < MAX_TIMEOUT)); + if (!(temp & NVIDIA_SMB_STATUS_ABRT_STS)) + dev_err(&adap->dev, "Can't reset the smbus\n"); + outb_p(NVIDIA_SMB_STATUS_ABRT_STS, NVIDIA_SMB_STATUS_ABRT); +} + static int nforce2_check_status(struct i2c_adapter *adap) { struct nforce2_smbus *smbus = adap->algo_data; @@ -116,6 +143,8 @@ static int nforce2_check_status(struct i2c_adapter *adap) if (timeout >= MAX_TIMEOUT) { dev_dbg(&adap->dev, "SMBus Timeout!\n"); + if (smbus->can_abort) + nforce2_abort(adap); return -1; } if (!(temp & NVIDIA_SMB_STS_DONE) || (temp & NVIDIA_SMB_STS_STATUS)) { @@ -325,6 +354,8 @@ static int __devinit nforce2_probe(struct pci_dev *dev, const struct pci_device_ case PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SMBUS: smbuses[0].blockops = 1; smbuses[1].blockops = 1; + smbuses[0].can_abort = 1; + smbuses[1].can_abort = 1; } /* SMBus adapter 1 */ |