Commit b7ef4e0b authored by Jean Delvare's avatar Jean Delvare Committed by Andi Shyti
Browse files

i2c: Drop legacy muxing pseudo-drivers 



The i2c-amd756-s4882 and i2c-nforce2-s4985 muxing pseudo-drivers were
written at a time when the i2c core did not support muxing. They are
essentially board-specific hacks. If we had to add support for these
boards today, we would implement it in a completely different way.

These Tyan server boards are 19 years old by now, so I very much doubt
any of these is still running today. So let's just drop this clumsy
code. If anyone really still needs this support and complains, I'll
rewrite it in a proper way on top of i2c-mux.

This also fixes the following warnings:
drivers/i2c/busses/i2c-amd756.c:286:20: warning: symbol 'amd756_smbus' was not declared. Should it be static?
drivers/i2c/busses/i2c-nforce2.c:123:20: warning: symbol 'nforce2_smbus' was not declared. Should it be static?

Signed-off-by: default avatarJean Delvare <jdelvare@suse.de>
Cc: Andi Shyti <andi.shyti@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: default avatarAndi Shyti <andi.shyti@kernel.org>
parent 5f5c2d45

MAINTAINERS

+0 −2
Original line number Diff line number Diff line
@@ -10722,12 +10722,10 @@ F: Documentation/i2c/busses/i2c-viapro.rst 
F:	drivers/i2c/busses/i2c-ali1535.c

F:	drivers/i2c/busses/i2c-ali1563.c

F:	drivers/i2c/busses/i2c-ali15x3.c

F:	drivers/i2c/busses/i2c-amd756-s4882.c

F:	drivers/i2c/busses/i2c-amd756.c

F:	drivers/i2c/busses/i2c-amd8111.c

F:	drivers/i2c/busses/i2c-i801.c

F:	drivers/i2c/busses/i2c-isch.c

F:	drivers/i2c/busses/i2c-nforce2-s4985.c

F:	drivers/i2c/busses/i2c-nforce2.c

F:	drivers/i2c/busses/i2c-piix4.*

F:	drivers/i2c/busses/i2c-sis5595.c

drivers/i2c/busses/Kconfig

+0 −26
Original line number Diff line number Diff line
@@ -62,19 +62,6 @@ config I2C_AMD756 
	  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 && X86

	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 PCI && HAS_IOPORT
@@ -268,19 +255,6 @@ config I2C_NFORCE2 
	  This driver can also be built as a module.  If so, the module

	  will be called i2c-nforce2.



config I2C_NFORCE2_S4985

	tristate "SMBus multiplexing on the Tyan S4985"

	depends on I2C_NFORCE2 && X86

	help

	  Enabling this option will add specific SMBus support for the Tyan

	  S4985 motherboard.  On this 4-CPU board, the SMBus is multiplexed

	  over 4 different channels, where the various memory module EEPROMs

	  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-nforce2-s4985.



config I2C_NVIDIA_GPU

	tristate "NVIDIA GPU I2C controller"

	depends on PCI

drivers/i2c/busses/Makefile

+0 −2
Original line number Diff line number Diff line
@@ -14,14 +14,12 @@ obj-$(CONFIG_I2C_ALI1535) += i2c-ali1535.o 
obj-$(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_CHT_WC)	+= i2c-cht-wc.o

obj-$(CONFIG_I2C_I801)		+= i2c-i801.o

obj-$(CONFIG_I2C_ISCH)		+= i2c-isch.o

obj-$(CONFIG_I2C_ISMT)		+= i2c-ismt.o

obj-$(CONFIG_I2C_NFORCE2)	+= i2c-nforce2.o

obj-$(CONFIG_I2C_NFORCE2_S4985)	+= i2c-nforce2-s4985.o

obj-$(CONFIG_I2C_NVIDIA_GPU)	+= i2c-nvidia-gpu.o

obj-$(CONFIG_I2C_PIIX4)		+= i2c-piix4.o

obj-$(CONFIG_I2C_SIS5595)	+= i2c-sis5595.o

drivers/i2c/busses/i2c-amd756-s4882.c

deleted100644 → 0
+0 −245
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * i2c-amd756-s4882.c - i2c-amd756 extras for the Tyan S4882 motherboard

 *

 * Copyright (C) 2004, 2008 Jean Delvare <jdelvare@suse.de>

 */

 

/*

 * 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/slab.h>

#include <linux/init.h>

#include <linux/i2c.h>

#include <linux/mutex.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 DEFINE_MUTEX(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 -ENXIO;



	mutex_lock(&amd756_lock);



	error = amd756_smbus.algo->smbus_xfer(adap, addr, flags, read_write,

					      command, size, data);



	mutex_unlock(&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 -ENXIO;



	mutex_lock(&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:

	mutex_unlock(&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;



	if (!amd756_smbus.dev.parent)

		return -ENODEV;



	/* Configure the PCA9556 multiplexer */

	ioconfig.byte = 0x00; /* All I/O to output mode */

	error = i2c_smbus_xfer(&amd756_smbus, 0x18, 0, I2C_SMBUS_WRITE, 0x03,

			       I2C_SMBUS_BYTE_DATA, &ioconfig);

	if (error) {

		dev_err(&amd756_smbus.dev, "PCA9556 configuration failed\n");

		error = -EIO;

		goto ERROR0;

	}



	/* Unregister physical bus */

	i2c_del_adapter(&amd756_smbus);



	printk(KERN_INFO "Enabling SMBus multiplexing for Tyan S4882\n");

	/* Define the 5 virtual adapters and algorithms structures */

	if (!(s4882_adapter = kcalloc(5, sizeof(struct i2c_adapter),

				      GFP_KERNEL))) {

		error = -ENOMEM;

		goto ERROR1;

	}

	if (!(s4882_algo = kcalloc(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;

	s4882_adapter[0].dev.parent = amd756_smbus.dev.parent;

	for (i = 1; i < 5; i++) {

		s4882_algo[i] = *(amd756_smbus.algo);

		s4882_adapter[i] = amd756_smbus;

		snprintf(s4882_adapter[i].name, sizeof(s4882_adapter[i].name),

			 "SMBus 8111 adapter (CPU%d)", i-1);

		s4882_adapter[i].algo = s4882_algo+i;

		s4882_adapter[i].dev.parent = amd756_smbus.dev.parent;

	}

	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;



	/* Register virtual adapters */

	for (i = 0; i < 5; i++) {

		error = i2c_add_adapter(s4882_adapter+i);

		if (error) {

			printk(KERN_ERR "i2c-amd756-s4882: "

			       "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:

	/* Restore physical bus */

	i2c_add_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;

	}

	kfree(s4882_algo);

	s4882_algo = NULL;



	/* Restore physical bus */

	if (i2c_add_adapter(&amd756_smbus))

		printk(KERN_ERR "i2c-amd756-s4882: "

		       "Physical bus restoration failed\n");

}



MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");

MODULE_DESCRIPTION("S4882 SMBus multiplexing");

MODULE_LICENSE("GPL");



module_init(amd756_s4882_init);

module_exit(amd756_s4882_exit);

drivers/i2c/busses/i2c-amd756.c

+1 −3
Original line number Diff line number Diff line
@@ -283,7 +283,7 @@ static const struct i2c_algorithm smbus_algorithm = { 
	.functionality	= amd756_func,

};



struct i2c_adapter amd756_smbus = {

static struct i2c_adapter amd756_smbus = {

	.owner		= THIS_MODULE,

	.class          = I2C_CLASS_HWMON,

	.algo		= &smbus_algorithm,
@@ -398,5 +398,3 @@ module_pci_driver(amd756_driver); 
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);