[i2c] [PATCH 2of3] change i2c-i801 driver to use internal 32-byte buffer on ICH4+
Oleg Ryjkov
olegr at google.com
Mon Jun 11 13:05:33 CEST 2007
Second part. The main change is here. See i2c mailing list for the
description of all the changes. ( Thread subject: "[i2c] [PATCH] change
to i2c-i801 driver to use internal 32-byte buffer on ICH4+".
Signed-off-by: Oleg Ryjkov <olegr at google.com>
--- linux-2.6-untouched/drivers/i2c/busses/i2c-i801.c 2007-06-11 03:43:18.000000000 -0700
+++ linux-2.6/drivers/i2c/busses/i2c-i801.c 2007-06-11 03:43:25.000000000 -0700
@@ -26,8 +26,8 @@
82801AB 2423
82801BA 2443
82801CA/CAM 2483
- 82801DB 24C3 (HW PEC supported, 32 byte buffer not supported)
- 82801EB 24D3 (HW PEC supported, 32 byte buffer not supported)
+ 82801DB 24C3 (HW PEC supported)
+ 82801EB 24D3 (HW PEC supported)
6300ESB 25A4
ICH6 266A
ICH7 27DA
@@ -114,7 +114,7 @@
static struct pci_dev *I801_dev;
static int isich4;
-static int i801_transaction(void)
+static int i801_transaction(int xact)
{
int temp;
int result = 0;
@@ -139,7 +139,9 @@
}
}
- outb_p(inb(SMBHSTCNT) | I801_START, SMBHSTCNT);
+ /* the current contents of SMBHSTCNT can be overwritten, since PEC,
+ * INTREN, SMBSCMD are passed in xact */
+ outb_p( xact | I801_START, SMBHSTCNT);
/* We will always wait for a fraction of a second! */
do {
@@ -207,44 +209,53 @@
outb_p(temp, SMBHSTSTS);
}
-/* All-inclusive block transaction function */
-static int i801_block_transaction(union i2c_smbus_data *data, char read_write,
- int command, int hwpec)
+static int i801_block_transaction_by_block(union i2c_smbus_data *data,
+ char read_write, int hwpec)
{
int i, len;
- int smbcmd;
+
+ inb_p(SMBHSTCNT); /* reset the data buffer index */
+
+ /* Use 32-byte buffer to process this transaction */
+ if (read_write == I2C_SMBUS_WRITE) {
+ len = data->block[0];
+ outb_p(len, SMBHSTDAT0);
+ for (i = 0; i < len; i++)
+ outb_p(data->block[i+1], SMBBLKDAT);
+ }
+
+ if (i801_transaction(I801_BLOCK_DATA | ENABLE_INT9 | hwpec))
+ return -1;
+
+ if (read_write == I2C_SMBUS_READ) {
+ len = inb_p(SMBHSTDAT0);
+ if (len < 1 || len > 32)
+ return -1;
+
+ data->block[0] = len;
+ for (i = 0; i < len; i++)
+ data->block[i + 1] = inb_p(SMBBLKDAT);
+ }
+ return 0;
+}
+
+static int i801_block_transaction_byte_by_byte(union i2c_smbus_data *data,
+ char read_write, int hwpec)
+{
+
int temp;
+ int i;
int result = 0;
+ int smbcmd;
int timeout;
- unsigned char hostc, errmask;
+ int len;
+ unsigned char errmask;
- if (command == I2C_SMBUS_I2C_BLOCK_DATA) {
- if (read_write == I2C_SMBUS_WRITE) {
- /* set I2C_EN bit in configuration register */
- pci_read_config_byte(I801_dev, SMBHSTCFG, &hostc);
- pci_write_config_byte(I801_dev, SMBHSTCFG,
- hostc | SMBHSTCFG_I2C_EN);
- } else {
- dev_err(&I801_dev->dev,
- "I2C_SMBUS_I2C_BLOCK_READ not DB!\n");
- return -1;
- }
- }
+ len = data->block[0];
if (read_write == I2C_SMBUS_WRITE) {
- len = data->block[0];
- if (len < 1)
- len = 1;
- if (len > 32)
- len = 32;
outb_p(len, SMBHSTDAT0);
outb_p(data->block[1], SMBBLKDAT);
- } else {
- len = 32; /* max for reads */
- }
-
- if(isich4 && command != I2C_SMBUS_I2C_BLOCK_DATA) {
- /* set 32 byte buffer */
}
for (i = 1; i <= len; i++) {
@@ -277,14 +288,11 @@
if (((temp = inb_p(SMBHSTSTS)) & errmask) != 0x00) {
dev_err(&I801_dev->dev,
"Reset failed! (%02x)\n", temp);
- result = -1;
- goto END;
+ return -1;
}
- if (i != 1) {
+ if (i != 1)
/* if die in middle of block transaction, fail */
- result = -1;
- goto END;
- }
+ return -1;
}
if (i == 1)
@@ -326,10 +334,8 @@
if (i == 1 && read_write == I2C_SMBUS_READ) {
len = inb_p(SMBHSTDAT0);
- if (len < 1 || len > 32) {
- result = -1;
- goto END;
- }
+ if (len < 1 || len > 32)
+ return -1;
data->block[0] = len;
}
@@ -352,14 +358,65 @@
inb_p(SMBHSTDAT0), inb_p(SMBBLKDAT));
if (result < 0)
- goto END;
+ return result;
}
+ return result;
+}
- if (hwpec)
+static int i801_set_block_buffer_mode(void)
+{
+ int temp;
+ temp = inb_p(SMBAUXCTL);
+ if (temp & SMBAUXCTL_E32B)
+ return 0;
+ dev_info(&I801_dev->dev, "Enabling 32-byte data buffer\n");
+ outb_p(inb_p(SMBAUXCTL) | SMBAUXCTL_E32B, SMBAUXCTL);
+ if ((inb_p(SMBAUXCTL) & SMBAUXCTL_E32B) == 0) {
+ dev_err(&I801_dev->dev, "Failed to set E32B bit\n");
+ return -1;
+ }
+ return 0;
+}
+
+/* Block transaction function */
+static int i801_block_transaction(union i2c_smbus_data *data, char read_write,
+ int command, int hwpec)
+{
+ int result = 0;
+ unsigned char hostc;
+
+ if (command == I2C_SMBUS_I2C_BLOCK_DATA) {
+ if (read_write == I2C_SMBUS_WRITE) {
+ /* set I2C_EN bit in configuration register */
+ pci_read_config_byte(I801_dev, SMBHSTCFG, &hostc);
+ pci_write_config_byte(I801_dev, SMBHSTCFG,
+ hostc | SMBHSTCFG_I2C_EN);
+ } else {
+ dev_err(&I801_dev->dev,
+ "I2C_SMBUS_I2C_BLOCK_READ not DB!\n");
+ return -1;
+ }
+ }
+
+ if (read_write == I2C_SMBUS_WRITE) {
+ if (data->block[0] < 1)
+ data->block[0] = 1;
+ if (data->block[0] > 32)
+ data->block[0] = 32;
+ } else {
+ data->block[0] = 32; /* max for reads */
+ }
+
+ if (isich4 && i801_set_block_buffer_mode() == 0 )
+ result = i801_block_transaction_by_block(data, read_write,
+ hwpec);
+ else
+ result = i801_block_transaction_byte_by_byte(data, read_write,
+ hwpec);
+
+ if (result == 0 && hwpec)
i801_wait_hwpec();
- result = 0;
-END:
if (command == I2C_SMBUS_I2C_BLOCK_DATA) {
/* restore saved configuration register value */
pci_write_config_byte(I801_dev, SMBHSTCFG, hostc);
@@ -430,15 +487,15 @@
if(block)
ret = i801_block_transaction(data, read_write, size, hwpec);
- else {
- outb_p(xact | ENABLE_INT9, SMBHSTCNT);
- ret = i801_transaction();
- }
+ else
+ ret = i801_transaction(xact | ENABLE_INT9);
/* Some BIOSes don't like it when PEC is enabled at reboot or resume
- time, so we forcibly disable it after every transaction. */
+ time, so we forcibly disable it after every transaction. Turn off
+ E32B for the same reason. */
if (hwpec)
- outb_p(inb_p(SMBAUXCTL) & (~SMBAUXCTL_CRC), SMBAUXCTL);
+ outb_p(inb_p(SMBAUXCTL) & ~(SMBAUXCTL_CRC | SMBAUXCTL_E32B),
+ SMBAUXCTL);
if(block)
return ret;
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