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[PATCH] i2c-viapro: Implement I2C Block transactions
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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@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

 Documentation/i2c/busses/i2c-viapro |    7 +++++-
 drivers/i2c/busses/i2c-viapro.c     |   39 +++++++++++++++++++++++++++++++++---
 2 files changed, 42 insertions(+), 4 deletions(-)
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Jean Delvare authored and Greg Kroah-Hartman committed Oct 28, 2005
1 parent 5f49ef8 commit f118301
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Showing 2 changed files with 42 additions and 4 deletions.
7 changes: 6 additions & 1 deletion Documentation/i2c/busses/i2c-viapro
Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,8 @@ Authors:
Frodo Looijaard <frodol@dds.nl>,
Philip Edelbrock <phil@netroedge.com>,
Ky�sti M�lkki <kmalkki@cc.hut.fi>,
Mark D. Studebaker <mdsxyz123@yahoo.com>
Mark D. Studebaker <mdsxyz123@yahoo.com>,
Jean Delvare <khali@linux-fr.org>

Module Parameters
-----------------
Expand Down Expand Up @@ -43,3 +44,7 @@ Your lspci -n listing must show one of these :

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.
39 changes: 36 additions & 3 deletions drivers/i2c/busses/i2c-viapro.c
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@
Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl>,
Philip Edelbrock <phil@netroedge.com>, Kyösti Mälkki <kmalkki@cc.hut.fi>,
Mark D. Studebaker <mdsxyz123@yahoo.com>
Copyright (C) 2005 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
Expand Down Expand Up @@ -88,6 +89,7 @@ static unsigned short smb_cf_hstcfg = 0xD2;
#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
Expand All @@ -107,6 +109,9 @@ MODULE_PARM_DESC(force_addr,

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)
{
Expand Down Expand Up @@ -225,6 +230,12 @@ static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
}
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);
Expand All @@ -240,11 +251,12 @@ static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
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;
Expand All @@ -266,6 +278,7 @@ static s32 vt596_access(struct i2c_adapter *adap, u16 addr,
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)
Expand All @@ -280,9 +293,13 @@ static s32 vt596_access(struct i2c_adapter *adap, u16 addr,

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 = {
Expand Down Expand Up @@ -379,6 +396,22 @@ static int __devinit vt596_probe(struct pci_dev *pdev,
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);
Expand Down

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