Hi Greg, all,
Implement the I2C block transactions on VIA chips which support them:
VT82C686B, VT8233, VT8233A, VT8235 and VT8237R. This speeds up EEPROM
accesses by a factor 10 or so.
I would like to thank Antonino A. Daplas, Hinko Kocevar, Salah Coronya
and Andreas Henriksson for their help in testing this new feature.
Signed-off-by: Jean Delvare <khali at linux-fr.org>
Documentation/i2c/busses/i2c-viapro | 7 +++++-
drivers/i2c/busses/i2c-viapro.c | 39 ++++++++++++++++++++++++++++++++---
2 files changed, 42 insertions(+), 4 deletions(-)
--- linux-2.6.13.orig/drivers/i2c/busses/i2c-viapro.c 2005-09-04 16:13:20.000000000 +0200
+++ linux-2.6.13/drivers/i2c/busses/i2c-viapro.c 2005-09-04 16:13:26.000000000 +0200
@@ -4,6 +4,7 @@
Copyright (c) 1998 - 2002 Frodo Looijaard <frodol at dds.nl>,
Philip Edelbrock <phil at netroedge.com>, Ky?sti M?lkki <kmalkki at cc.hut.fi>,
Mark D. Studebaker <mdsxyz123 at yahoo.com>
+ Copyright (C) 2005 Jean Delvare <khali at 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
@@ -88,6 +89,7 @@
#define VT596_BYTE_DATA 0x08
#define VT596_WORD_DATA 0x0C
#define VT596_BLOCK_DATA 0x14
+#define VT596_I2C_BLOCK_DATA 0x34
/* If force is set to anything different from 0, we forcibly enable the
@@ -107,6 +109,9 @@
static struct i2c_adapter vt596_adapter;
+#define FEATURE_I2CBLOCK (1<<0)
+static unsigned int vt596_features;
+
/* Another internally used function */
static int vt596_transaction(void)
{
@@ -225,6 +230,12 @@
}
size = VT596_WORD_DATA;
break;
+ case I2C_SMBUS_I2C_BLOCK_DATA:
+ if (!(vt596_features & FEATURE_I2CBLOCK))
+ return -1;
+ if (read_write == I2C_SMBUS_READ)
+ outb_p(I2C_SMBUS_BLOCK_MAX, SMBHSTDAT0);
+ /* Fall through */
case I2C_SMBUS_BLOCK_DATA:
outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
SMBHSTADD);
@@ -240,11 +251,12 @@
for (i = 1; i <= len; i++)
outb_p(data->block[i], SMBBLKDAT);
}
- size = VT596_BLOCK_DATA;
+ size = (size == I2C_SMBUS_I2C_BLOCK_DATA) ?
+ VT596_I2C_BLOCK_DATA : VT596_BLOCK_DATA;
break;
}
- outb_p((size & 0x1C) + (ENABLE_INT9 & 1), SMBHSTCNT);
+ outb_p((size & 0x3C) + (ENABLE_INT9 & 1), SMBHSTCNT);
if (vt596_transaction()) /* Error in transaction */
return -1;
@@ -266,6 +278,7 @@
case VT596_WORD_DATA:
data->word = inb_p(SMBHSTDAT0) + (inb_p(SMBHSTDAT1) << 8);
break;
+ case VT596_I2C_BLOCK_DATA:
case VT596_BLOCK_DATA:
data->block[0] = inb_p(SMBHSTDAT0);
if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
@@ -280,9 +293,13 @@
static u32 vt596_func(struct i2c_adapter *adapter)
{
- return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
+ u32 func = I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_BLOCK_DATA;
+
+ if (vt596_features & FEATURE_I2CBLOCK)
+ func |= I2C_FUNC_SMBUS_I2C_BLOCK;
+ return func;
}
static struct i2c_algorithm smbus_algorithm = {
@@ -379,6 +396,22 @@
dev_dbg(&pdev->dev, "SMBREV = 0x%X\n", temp);
dev_dbg(&pdev->dev, "VT596_smba = 0x%X\n", vt596_smba);
+ switch (pdev->device) {
+ case PCI_DEVICE_ID_VIA_8237:
+ case PCI_DEVICE_ID_VIA_8235:
+ case PCI_DEVICE_ID_VIA_8233A:
+ case PCI_DEVICE_ID_VIA_8233_0:
+ vt596_features |= FEATURE_I2CBLOCK;
+ break;
+ case PCI_DEVICE_ID_VIA_82C686_4:
+ /* The VT82C686B (rev 0x40) does support I2C block
+ transactions, but the VT82C686A (rev 0x30) doesn't */
+ if (!pci_read_config_byte(pdev, PCI_REVISION_ID, &temp)
+ && temp >= 0x40)
+ vt596_features |= FEATURE_I2CBLOCK;
+ break;
+ }
+
vt596_adapter.dev.parent = &pdev->dev;
snprintf(vt596_adapter.name, I2C_NAME_SIZE,
"SMBus Via Pro adapter at %04x", vt596_smba);
--- linux-2.6.13.orig/Documentation/i2c/busses/i2c-viapro 2005-09-04 16:13:20.000000000 +0200
+++ linux-2.6.13/Documentation/i2c/busses/i2c-viapro 2005-09-04 16:13:26.000000000 +0200
@@ -14,7 +14,8 @@
Frodo Looijaard <frodol at dds.nl>,
Philip Edelbrock <phil at netroedge.com>,
Ky?sti M?lkki <kmalkki at cc.hut.fi>,
- Mark D. Studebaker <mdsxyz123 at yahoo.com>
+ Mark D. Studebaker <mdsxyz123 at yahoo.com>,
+ Jean Delvare <khali at linux-fr.org>
Module Parameters
-----------------
@@ -43,3 +44,7 @@
If none of these show up, you should look in the BIOS for settings like
enable ACPI / SMBus or even USB.
+
+Except for the oldest chips (VT82C596A/B, VT82C686A and most probably
+VT8231), this driver supports I2C block transactions. Such transactions
+are mainly useful to read from and write to EEPROMs.
--
Jean Delvare
