Re: [PATCH] I2C update for 2.6.10-rc1

Greg KH
2004-11-09T05:50:18Z

ChangeSet 1.2014.1.24, 2004/11/08 16:46:18-08:00, khali@linux-fr.org

[PATCH] I2C: add Tyan S4882 driver

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/i2c/busses/Kconfig | 13 +
drivers/i2c/busses/Makefile | 1
drivers/i2c/busses/i2c-amd756-s4882.c | 261 ++++++++++++++++++++++++++++++++++
drivers/i2c/busses/i2c-amd756.c | 12 -
4 files changed, 282 insertions(+), 5 deletions(-)

diff -Nru a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
--- a/drivers/i2c/busses/Kconfig 2004-11-08 18:54:23 -08:00
+++ b/drivers/i2c/busses/Kconfig 2004-11-08 18:54:23 -08:00
@@ -51,6 +51,19 @@
This driver can also be built as a module. If so, the module
will be called i2c-amd756.

+config I2C_AMD756_S4882
+ tristate "SMBus multiplexing on the Tyan S4882"
+ depends on I2C_AMD756 && EXPERIMENTAL
+ help
+ Enabling this option will add specific SMBus support for the Tyan
+ S4882 motherboard. On this 4-CPU board, the SMBus is multiplexed
+ over 8 different channels, where the various memory module EEPROMs
+ and temperature sensors live. Saying yes here will give you access
+ to these in addition to the trunk.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-amd756-s4882.
+
config I2C_AMD8111
tristate "AMD 8111"
depends on I2C && PCI && EXPERIMENTAL
diff -Nru a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
--- a/drivers/i2c/busses/Makefile 2004-11-08 18:54:23 -08:00
+++ b/drivers/i2c/busses/Makefile 2004-11-08 18:54:23 -08:00
@@ -6,6 +6,7 @@
obj-$(CONFIG_I2C_ALI1563) += i2c-ali1563.o
obj-$(CONFIG_I2C_ALI15X3) += i2c-ali15x3.o
obj-$(CONFIG_I2C_AMD756) += i2c-amd756.o
+obj-$(CONFIG_I2C_AMD756_S4882) += i2c-amd756-s4882.o
obj-$(CONFIG_I2C_AMD8111) += i2c-amd8111.o
obj-$(CONFIG_I2C_ELEKTOR) += i2c-elektor.o
obj-$(CONFIG_I2C_HYDRA) += i2c-hydra.o
diff -Nru a/drivers/i2c/busses/i2c-amd756-s4882.c b/drivers/i2c/busses/i2c-amd756-s4882.c
--- /dev/null Wed Dec 31 16:00:00 196900
+++ b/drivers/i2c/busses/i2c-amd756-s4882.c 2004-11-08 18:54:23 -08:00
@@ -0,0 +1,261 @@
+/*
+ * i2c-amd756-s4882.c - i2c-amd756 extras for the Tyan S4882 motherboard
+ *
+ * Copyright (C) 2004 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
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/*
+ * We select the channels by sending commands to the Philips
+ * PCA9556 chip at I2C address 0x18. The main adapter is used for
+ * the non-multiplexed part of the bus, and 4 virtual adapters
+ * are defined for the multiplexed addresses: 0x50-0x53 (memory
+ * module EEPROM) located on channels 1-4, and 0x4c (LM63)
+ * located on multiplexed channels 0 and 5-7. We define one
+ * virtual adapter per CPU, which corresponds to two multiplexed
+ * channels:
+ * CPU0: virtual adapter 1, channels 1 and 0
+ * CPU1: virtual adapter 2, channels 2 and 5
+ * CPU2: virtual adapter 3, channels 3 and 6
+ * CPU3: virtual adapter 4, channels 4 and 7
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+
+extern struct i2c_adapter amd756_smbus;
+
+static struct i2c_adapter *s4882_adapter;
+static struct i2c_algorithm *s4882_algo;
+
+/* Wrapper access functions for multiplexed SMBus */
+static struct semaphore amd756_lock;
+
+static s32 amd756_access_virt0(struct i2c_adapter * adap, u16 addr,
+ unsigned short flags, char read_write,
+ u8 command, int size,
+ union i2c_smbus_data * data)
+{
+ int error;
+
+ /* We exclude the multiplexed addresses */
+ if (addr == 0x4c || (addr & 0xfc) == 0x50 || (addr & 0xfc) == 0x30
+ || addr == 0x18)
+ return -1;
+
+ down(&amd756_lock);
+
+ error = amd756_smbus.algo->smbus_xfer(adap, addr, flags, read_write,
+ command, size, data);
+
+ up(&amd756_lock);
+
+ return error;
+}
+
+/* We remember the last used channels combination so as to only switch
+ channels when it is really needed. This greatly reduces the SMBus
+ overhead, but also assumes that nobody will be writing to the PCA9556
+ in our back. */
+static u8 last_channels;
+
+static inline s32 amd756_access_channel(struct i2c_adapter * adap, u16 addr,
+ unsigned short flags, char read_write,
+ u8 command, int size,
+ union i2c_smbus_data * data,
+ u8 channels)
+{
+ int error;
+
+ /* We exclude the non-multiplexed addresses */
+ if (addr != 0x4c && (addr & 0xfc) != 0x50 && (addr & 0xfc) != 0x30)
+ return -1;
+
+ down(&amd756_lock);
+
+ if (last_channels != channels) {
+ union i2c_smbus_data mplxdata;
+ mplxdata.byte = channels;
+
+ error = amd756_smbus.algo->smbus_xfer(adap, 0x18, 0,
+ I2C_SMBUS_WRITE, 0x01,
+ I2C_SMBUS_BYTE_DATA,
+ &mplxdata);
+ if (error)
+ goto UNLOCK;
+ last_channels = channels;
+ }
+ error = amd756_smbus.algo->smbus_xfer(adap, addr, flags, read_write,
+ command, size, data);
+
+UNLOCK:
+ up(&amd756_lock);
+ return error;
+}
+
+static s32 amd756_access_virt1(struct i2c_adapter * adap, u16 addr,
+ unsigned short flags, char read_write,
+ u8 command, int size,
+ union i2c_smbus_data * data)
+{
+ /* CPU0: channels 1 and 0 enabled */
+ return amd756_access_channel(adap, addr, flags, read_write, command,
+ size, data, 0x03);
+}
+
+static s32 amd756_access_virt2(struct i2c_adapter * adap, u16 addr,
+ unsigned short flags, char read_write,
+ u8 command, int size,
+ union i2c_smbus_data * data)
+{
+ /* CPU1: channels 2 and 5 enabled */
+ return amd756_access_channel(adap, addr, flags, read_write, command,
+ size, data, 0x24);
+}
+
+static s32 amd756_access_virt3(struct i2c_adapter * adap, u16 addr,
+ unsigned short flags, char read_write,
+ u8 command, int size,
+ union i2c_smbus_data * data)
+{
+ /* CPU2: channels 3 and 6 enabled */
+ return amd756_access_channel(adap, addr, flags, read_write, command,
+ size, data, 0x48);
+}
+
+static s32 amd756_access_virt4(struct i2c_adapter * adap, u16 addr,
+ unsigned short flags, char read_write,
+ u8 command, int size,
+ union i2c_smbus_data * data)
+{
+ /* CPU3: channels 4 and 7 enabled */
+ return amd756_access_channel(adap, addr, flags, read_write, command,
+ size, data, 0x90);
+}
+
+static int __init amd756_s4882_init(void)
+{
+ int i, error;
+ union i2c_smbus_data ioconfig;
+
+ /* Unregister physical bus */
+ error = i2c_del_adapter(&amd756_smbus);
+ if (error) {
+ if (error != -EINVAL)
+ dev_err(&amd756_smbus.dev, "Physical bus removal "
+ "failed\n");
+ goto ERROR0;
+ }
+
+ printk(KERN_INFO "Enabling SMBus multiplexing for Tyan S4882\n");
+ init_MUTEX(&amd756_lock);
+
+ /* Define the 5 virtual adapters and algorithms structures */
+ if (!(s4882_adapter = kmalloc(5 * sizeof(struct i2c_adapter),
+ GFP_KERNEL))) {
+ error = -ENOMEM;
+ goto ERROR1;
+ }
+ if (!(s4882_algo = kmalloc(5 * sizeof(struct i2c_algorithm),
+ GFP_KERNEL))) {
+ error = -ENOMEM;
+ goto ERROR2;
+ }
+
+ /* Fill in the new structures */
+ s4882_algo[0] = *(amd756_smbus.algo);
+ s4882_algo[0].smbus_xfer = amd756_access_virt0;
+ s4882_adapter[0] = amd756_smbus;
+ s4882_adapter[0].algo = s4882_algo;
+ for (i = 1; i < 5; i++) {
+ s4882_algo[i] = *(amd756_smbus.algo);
+ s4882_adapter[i] = amd756_smbus;
+ sprintf(s4882_adapter[i].name,
+ "SMBus 8111 adapter (CPU%d)", i-1);
+ s4882_adapter[i].algo = s4882_algo+i;
+ }
+ s4882_algo[1].smbus_xfer = amd756_access_virt1;
+ s4882_algo[2].smbus_xfer = amd756_access_virt2;
+ s4882_algo[3].smbus_xfer = amd756_access_virt3;
+ s4882_algo[4].smbus_xfer = amd756_access_virt4;
+
+ /* Configure the PCA9556 multiplexer */
+ ioconfig.byte = 0x00; /* All I/O to output mode */
+ error = amd756_smbus.algo->smbus_xfer(&amd756_smbus, 0x18, 0,
+ I2C_SMBUS_WRITE, 0x03,
+ I2C_SMBUS_BYTE_DATA, &ioconfig);
+ if (error) {
+ dev_dbg(&amd756_smbus.dev, "PCA9556 configuration failed\n");
+ error = -EIO;
+ goto ERROR3;
+ }
+
+ /* Register virtual adapters */
+ for (i = 0; i < 5; i++) {
+ error = i2c_add_adapter(s4882_adapter+i);
+ if (error) {
+ dev_err(&amd756_smbus.dev,
+ "Virtual adapter %d registration "
+ "failed, module not inserted\n", i);
+ for (i--; i >= 0; i--)
+ i2c_del_adapter(s4882_adapter+i);
+ goto ERROR3;
+ }
+ }
+
+ return 0;
+
+ERROR3:
+ kfree(s4882_algo);
+ s4882_algo = NULL;
+ERROR2:
+ kfree(s4882_adapter);
+ s4882_adapter = NULL;
+ERROR1:
+ i2c_del_adapter(&amd756_smbus);
+ERROR0:
+ return error;
+}
+
+static void __exit amd756_s4882_exit(void)
+{
+ if (s4882_adapter) {
+ int i;
+
+ for (i = 0; i < 5; i++)
+ i2c_del_adapter(s4882_adapter+i);
+ kfree(s4882_adapter);
+ s4882_adapter = NULL;
+ }
+ if (s4882_algo) {
+ kfree(s4882_algo);
+ s4882_algo = NULL;
+ }
+
+ /* Restore physical bus */
+ if (i2c_add_adapter(&amd756_smbus))
+ dev_err(&amd756_smbus.dev, "Physical bus restoration "
+ "failed\n");
+}
+
+MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
+MODULE_DESCRIPTION("S4882 SMBus multiplexing");
+MODULE_LICENSE("GPL");
+
+module_init(amd756_s4882_init);
+module_exit(amd756_s4882_exit);
diff -Nru a/drivers/i2c/busses/i2c-amd756.c b/drivers/i2c/busses/i2c-amd756.c
--- a/drivers/i2c/busses/i2c-amd756.c 2004-11-08 18:54:23 -08:00
+++ b/drivers/i2c/busses/i2c-amd756.c 2004-11-08 18:54:23 -08:00
@@ -302,7 +302,7 @@
.functionality = amd756_func,
};

-static struct i2c_adapter amd756_adapter = {
+struct i2c_adapter amd756_smbus = {
.owner = THIS_MODULE,
.class = I2C_CLASS_HWMON,
.algo = &smbus_algorithm,
@@ -374,12 +374,12 @@
dev_dbg(&pdev->dev, "AMD756_smba = 0x%X\n", amd756_ioport);

/* set up the driverfs linkage to our parent device */
- amd756_adapter.dev.parent = &pdev->dev;
+ amd756_smbus.dev.parent = &pdev->dev;

- sprintf(amd756_adapter.name, "SMBus %s adapter at %04x",
+ sprintf(amd756_smbus.name, "SMBus %s adapter at %04x",
chipname[id->driver_data], amd756_ioport);

- error = i2c_add_adapter(&amd756_adapter);
+ error = i2c_add_adapter(&amd756_smbus);
if (error) {
dev_err(&pdev->dev,
"Adapter registration failed, module not inserted\n");
@@ -395,7 +395,7 @@

static void __devexit amd756_remove(struct pci_dev *dev)
{
- i2c_del_adapter(&amd756_adapter);
+ i2c_del_adapter(&amd756_smbus);
release_region(amd756_ioport, SMB_IOSIZE);
}

@@ -419,6 +419,8 @@
MODULE_AUTHOR("Merlin Hughes <merlin@merlin.org>");
MODULE_DESCRIPTION("AMD756/766/768/8111 and nVidia nForce SMBus driver");
MODULE_LICENSE("GPL");
+
+EXPORT_SYMBOL(amd756_smbus);

module_init(amd756_init)
module_exit(amd756_exit)