From 4153549734cbdba24e9cf5eb200b70b7b1572e15 Mon Sep 17 00:00:00 2001 From: Oleg Ryjkov Date: Sat, 13 Oct 2007 23:56:33 +0200 Subject: [PATCH] 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 Signed-off-by: Jean Delvare --- drivers/i2c/busses/i2c-nforce2.c | 49 +++++++++++++++++++++----------- 1 file changed, 33 insertions(+), 16 deletions(-) diff --git a/drivers/i2c/busses/i2c-nforce2.c b/drivers/i2c/busses/i2c-nforce2.c index c48140f782d0..1c63c4f2e4b6 100644 --- a/drivers/i2c/busses/i2c-nforce2.c +++ b/drivers/i2c/busses/i2c-nforce2.c @@ -98,15 +98,40 @@ struct nforce2_smbus { #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 @@ static s32 nforce2_access(struct i2c_adapter * adap, u16 addr, 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 @@ static s32 nforce2_access(struct i2c_adapter * adap, u16 addr, 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;