i2c-i801: Implement I2C block read support
I2C block read is supported since the ICH5. I couldn't get it to work
using the block buffer, so it's using the old-style byte-by-byte mode
for now.
Note: I'm also updating the driver author... The i2c-i801 driver was
really written by Mark Studebaker, even though he based his work on
the i2c-piix4 driver which was written by Philip Edelbrock.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 0b1b1ae..aa91579 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -4,6 +4,7 @@
Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl>,
Philip Edelbrock <phil@netroedge.com>, and Mark D. Studebaker
<mdsxyz123@yahoo.com>
+ Copyright (C) 2007 Jean Delvare <khali@linux-fr.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -46,7 +47,7 @@
Hardware PEC yes
Block buffer yes
Block process call transaction no
- I2C block read transaction no
+ I2C block read transaction yes (doesn't use the block buffer)
See the file Documentation/i2c/busses/i2c-i801 for details.
*/
@@ -102,9 +103,9 @@
#define I801_WORD_DATA 0x0C
#define I801_PROC_CALL 0x10 /* unimplemented */
#define I801_BLOCK_DATA 0x14
-#define I801_I2C_BLOCK_DATA 0x18 /* unimplemented */
+#define I801_I2C_BLOCK_DATA 0x18 /* ICH5 and later */
#define I801_BLOCK_LAST 0x34
-#define I801_I2C_BLOCK_LAST 0x38 /* unimplemented */
+#define I801_I2C_BLOCK_LAST 0x38 /* ICH5 and later */
#define I801_START 0x40
#define I801_PEC_EN 0x80 /* ICH3 and later */
@@ -256,7 +257,8 @@
}
static int i801_block_transaction_byte_by_byte(union i2c_smbus_data *data,
- char read_write, int hwpec)
+ char read_write, int command,
+ int hwpec)
{
int i, len;
int smbcmd;
@@ -273,16 +275,24 @@
}
for (i = 1; i <= len; i++) {
- if (i == len && read_write == I2C_SMBUS_READ)
- smbcmd = I801_BLOCK_LAST;
- else
- smbcmd = I801_BLOCK_DATA;
+ if (i == len && read_write == I2C_SMBUS_READ) {
+ if (command == I2C_SMBUS_I2C_BLOCK_DATA)
+ smbcmd = I801_I2C_BLOCK_LAST;
+ else
+ smbcmd = I801_BLOCK_LAST;
+ } else {
+ if (command == I2C_SMBUS_I2C_BLOCK_DATA
+ && read_write == I2C_SMBUS_READ)
+ smbcmd = I801_I2C_BLOCK_DATA;
+ else
+ smbcmd = I801_BLOCK_DATA;
+ }
outb_p(smbcmd | ENABLE_INT9, SMBHSTCNT);
dev_dbg(&I801_dev->dev, "Block (pre %d): CNT=%02x, CMD=%02x, "
- "ADD=%02x, DAT0=%02x, BLKDAT=%02x\n", i,
+ "ADD=%02x, DAT0=%02x, DAT1=%02x, BLKDAT=%02x\n", i,
inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
- inb_p(SMBHSTDAT0), inb_p(SMBBLKDAT));
+ inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1), inb_p(SMBBLKDAT));
/* Make sure the SMBus host is ready to start transmitting */
temp = inb_p(SMBHSTSTS);
@@ -346,7 +356,8 @@
dev_dbg(&I801_dev->dev, "Error: no response!\n");
}
- if (i == 1 && read_write == I2C_SMBUS_READ) {
+ if (i == 1 && read_write == I2C_SMBUS_READ
+ && command != I2C_SMBUS_I2C_BLOCK_DATA) {
len = inb_p(SMBHSTDAT0);
if (len < 1 || len > I2C_SMBUS_BLOCK_MAX)
return -1;
@@ -367,9 +378,9 @@
temp);
}
dev_dbg(&I801_dev->dev, "Block (post %d): CNT=%02x, CMD=%02x, "
- "ADD=%02x, DAT0=%02x, BLKDAT=%02x\n", i,
+ "ADD=%02x, DAT0=%02x, DAT1=%02x, BLKDAT=%02x\n", i,
inb_p(SMBHSTCNT), inb_p(SMBHSTCMD), inb_p(SMBHSTADD),
- inb_p(SMBHSTDAT0), inb_p(SMBBLKDAT));
+ inb_p(SMBHSTDAT0), inb_p(SMBHSTDAT1), inb_p(SMBBLKDAT));
if (result < 0)
return result;
@@ -398,34 +409,38 @@
pci_read_config_byte(I801_dev, SMBHSTCFG, &hostc);
pci_write_config_byte(I801_dev, SMBHSTCFG,
hostc | SMBHSTCFG_I2C_EN);
- } else {
+ } else if (!(i801_features & FEATURE_I2C_BLOCK_READ)) {
dev_err(&I801_dev->dev,
- "I2C_SMBUS_I2C_BLOCK_READ not DB!\n");
+ "I2C block read is unsupported!\n");
return -1;
}
}
- if (read_write == I2C_SMBUS_WRITE) {
+ if (read_write == I2C_SMBUS_WRITE
+ || command == I2C_SMBUS_I2C_BLOCK_DATA) {
if (data->block[0] < 1)
data->block[0] = 1;
if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
data->block[0] = I2C_SMBUS_BLOCK_MAX;
} else {
- data->block[0] = 32; /* max for reads */
+ data->block[0] = 32; /* max for SMBus block reads */
}
if ((i801_features & FEATURE_BLOCK_BUFFER)
+ && !(command == I2C_SMBUS_I2C_BLOCK_DATA
+ && read_write == I2C_SMBUS_READ)
&& 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);
+ command, hwpec);
if (result == 0 && hwpec)
i801_wait_hwpec();
- if (command == I2C_SMBUS_I2C_BLOCK_DATA) {
+ if (command == I2C_SMBUS_I2C_BLOCK_DATA
+ && read_write == I2C_SMBUS_WRITE) {
/* restore saved configuration register value */
pci_write_config_byte(I801_dev, SMBHSTCFG, hostc);
}
@@ -477,12 +492,23 @@
xact = I801_WORD_DATA;
break;
case I2C_SMBUS_BLOCK_DATA:
- case I2C_SMBUS_I2C_BLOCK_DATA:
outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
SMBHSTADD);
outb_p(command, SMBHSTCMD);
block = 1;
break;
+ case I2C_SMBUS_I2C_BLOCK_DATA:
+ /* NB: page 240 of ICH5 datasheet shows that the R/#W
+ * bit should be cleared here, even when reading */
+ outb_p((addr & 0x7f) << 1, SMBHSTADD);
+ if (read_write == I2C_SMBUS_READ) {
+ /* NB: page 240 of ICH5 datasheet also shows
+ * that DATA1 is the cmd field when reading */
+ outb_p(command, SMBHSTDAT1);
+ } else
+ outb_p(command, SMBHSTCMD);
+ block = 1;
+ break;
case I2C_SMBUS_PROC_CALL:
default:
dev_err(&I801_dev->dev, "Unsupported transaction %d\n", size);
@@ -531,7 +557,9 @@
return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK |
- ((i801_features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0);
+ ((i801_features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) |
+ ((i801_features & FEATURE_I2C_BLOCK_READ) ?
+ I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0);
}
static const struct i2c_algorithm smbus_algorithm = {
@@ -573,7 +601,6 @@
I801_dev = dev;
i801_features = 0;
switch (dev->device) {
- case PCI_DEVICE_ID_INTEL_82801DB_3:
case PCI_DEVICE_ID_INTEL_82801EB_3:
case PCI_DEVICE_ID_INTEL_ESB_4:
case PCI_DEVICE_ID_INTEL_ICH6_16:
@@ -581,6 +608,9 @@
case PCI_DEVICE_ID_INTEL_ESB2_17:
case PCI_DEVICE_ID_INTEL_ICH8_5:
case PCI_DEVICE_ID_INTEL_ICH9_6:
+ i801_features |= FEATURE_I2C_BLOCK_READ;
+ /* fall through */
+ case PCI_DEVICE_ID_INTEL_82801DB_3:
case PCI_DEVICE_ID_INTEL_TOLAPAI_1:
i801_features |= FEATURE_SMBUS_PEC;
i801_features |= FEATURE_BLOCK_BUFFER;
@@ -698,9 +728,8 @@
pci_unregister_driver(&i801_driver);
}
-MODULE_AUTHOR ("Frodo Looijaard <frodol@dds.nl>, "
- "Philip Edelbrock <phil@netroedge.com>, "
- "and Mark D. Studebaker <mdsxyz123@yahoo.com>");
+MODULE_AUTHOR("Mark D. Studebaker <mdsxyz123@yahoo.com>, "
+ "Jean Delvare <khali@linux-fr.org>");
MODULE_DESCRIPTION("I801 SMBus driver");
MODULE_LICENSE("GPL");