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Commit 41535497 authored by Oleg Ryjkov's avatar Oleg Ryjkov Committed by Jean Delvare
Browse files

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: default avatarOleg Ryjkov <olegr@olegr.ca>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent a202707e

drivers/i2c/busses/i2c-nforce2.c

+33 −16
Original line number Diff line number Diff line
@@ -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;