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i2c: sis630: use hex to constants for SMBus commands
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This patch replaces hexadecimal values by constants for SMBus commands.

Signed-off-by: Amaury Decrême <amaury.decreme@gmail.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
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Amaury Decrême authored and Wolfram Sang committed Feb 11, 2013
1 parent 499b919 commit a6e7d0e
Showing 1 changed file with 31 additions and 14 deletions.
45 changes: 31 additions & 14 deletions drivers/i2c/busses/i2c-sis630.c
Original file line number Diff line number Diff line change
Expand Up @@ -81,6 +81,21 @@
#define SMB_COUNT 0x07 /* byte count */
#define SMB_BYTE 0x08 /* ~0x8F data byte field */

/* SMB_STS register */
#define BYTE_DONE_STS 0x10 /* Byte Done Status / Block Array */
#define SMBCOL_STS 0x04 /* Collision */
#define SMBERR_STS 0x02 /* Device error */

/* SMB_CNT register */
#define MSTO_EN 0x40 /* Host Master Timeout Enable */
#define SMBCLK_SEL 0x20 /* Host master clock selection */
#define SMB_PROBE 0x02 /* Bus Probe/Slave busy */
#define SMB_HOSTBUSY 0x01 /* Host Busy */

/* SMBHOST_CNT register */
#define SMB_KILL 0x20 /* Kill */
#define SMB_START 0x10 /* Start */

/* register count for request_region
* As we don't use SMB_PCOUNT, 20 is ok for SiS630 and SiS964
*/
Expand Down Expand Up @@ -140,12 +155,14 @@ static int sis630_transaction_start(struct i2c_adapter *adap, int size, u8 *oldc
int temp;

/* Make sure the SMBus host is ready to start transmitting. */
if ((temp = sis630_read(SMB_CNT) & 0x03) != 0x00) {
dev_dbg(&adap->dev, "SMBus busy (%02x).Resetting...\n",temp);
temp = sis630_read(SMB_CNT);
if ((temp & (SMB_PROBE | SMB_HOSTBUSY)) != 0x00) {
dev_dbg(&adap->dev, "SMBus busy (%02x). Resetting...\n", temp);
/* kill smbus transaction */
sis630_write(SMBHOST_CNT, 0x20);
sis630_write(SMBHOST_CNT, SMB_KILL);

if ((temp = sis630_read(SMB_CNT) & 0x03) != 0x00) {
temp = sis630_read(SMB_CNT);
if (temp & (SMB_PROBE | SMB_HOSTBUSY)) {
dev_dbg(&adap->dev, "Failed! (%02x)\n", temp);
return -EBUSY;
} else {
Expand All @@ -160,16 +177,16 @@ static int sis630_transaction_start(struct i2c_adapter *adap, int size, u8 *oldc

/* disable timeout interrupt , set Host Master Clock to 56KHz if requested */
if (high_clock)
sis630_write(SMB_CNT, 0x20);
sis630_write(SMB_CNT, SMBCLK_SEL);
else
sis630_write(SMB_CNT, (*oldclock & ~0x40));
sis630_write(SMB_CNT, (*oldclock & ~MSTO_EN));

/* clear all sticky bits */
temp = sis630_read(SMB_STS);
sis630_write(SMB_STS, temp & 0x1e);

/* start the transaction by setting bit 4 and size */
sis630_write(SMBHOST_CNT,0x10 | (size & 0x07));
sis630_write(SMBHOST_CNT, SMB_START | (size & 0x07));

return 0;
}
Expand All @@ -183,7 +200,7 @@ static int sis630_transaction_wait(struct i2c_adapter *adap, int size)
msleep(1);
temp = sis630_read(SMB_STS);
/* check if block transmitted */
if (size == SIS630_BLOCK_DATA && (temp & 0x10))
if (size == SIS630_BLOCK_DATA && (temp & BYTE_DONE_STS))
break;
} while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));

Expand All @@ -193,12 +210,12 @@ static int sis630_transaction_wait(struct i2c_adapter *adap, int size)
result = -ETIMEDOUT;
}

if (temp & 0x02) {
if (temp & SMBERR_STS) {
dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
result = -ENXIO;
}

if (temp & 0x04) {
if (temp & SMBCOL_STS) {
dev_err(&adap->dev, "Bus collision!\n");
result = -EAGAIN;
}
Expand All @@ -217,8 +234,8 @@ static void sis630_transaction_end(struct i2c_adapter *adap, u8 oldclock)
* restore old Host Master Clock if high_clock is set
* and oldclock was not 56KHz
*/
if (high_clock && !(oldclock & 0x20))
sis630_write(SMB_CNT,(sis630_read(SMB_CNT) & ~0x20));
if (high_clock && !(oldclock & SMBCLK_SEL))
sis630_write(SMB_CNT, sis630_read(SMB_CNT) & ~SMBCLK_SEL);

dev_dbg(&adap->dev, "SMB_CNT after clock restore 0x%02x\n", sis630_read(SMB_CNT));
}
Expand Down Expand Up @@ -270,7 +287,7 @@ static int sis630_block_data(struct i2c_adapter *adap, union i2c_smbus_data *dat
we must clear sticky bit.
clear SMBARY_STS
*/
sis630_write(SMB_STS,0x10);
sis630_write(SMB_STS, BYTE_DONE_STS);
}
rc = sis630_transaction_wait(adap,
SIS630_BLOCK_DATA);
Expand Down Expand Up @@ -312,7 +329,7 @@ static int sis630_block_data(struct i2c_adapter *adap, union i2c_smbus_data *dat
dev_dbg(&adap->dev, "clear smbary_sts len=%d i=%d\n",len,i);

/* clear SMBARY_STS */
sis630_write(SMB_STS,0x10);
sis630_write(SMB_STS, BYTE_DONE_STS);
} while(len < data->block[0]);
}

Expand Down

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