Re: [PATCH] ACPI: add driver for SMBus Control Method Interface

ykzhao
2009-07-15T09:42:42Z

On Wed, 2009-07-15 at 14:02 +0800, Crane Cai wrote:
> This driver supports the SMBus Control Method Interface. It needs BIOS declare
> ACPI control methods via SMBus Control Method Interface Spec.
It seems that SM bus control is realized in BIOS. And OS can use the
given control method interface to access it.
Will this controller be accessed directly directly BIOS?
If it can be accessed by BIOS, how to resolve the conflict between BIOS
and OS?

In fact we see the conflict on some boxes. The SMbus controller will be
accessed by BIOS. If the corresponding driver is loaded for the SMBUS
controller, there exists the potential risk. In such case we will hide
the SMbus controller or not load the device driver for it.

Thanks.
>
> Please apply
>
> Signed-off-by: Crane Cai <crane.cai@amd.com>
> ---
> drivers/acpi/Kconfig | 11 ++
> drivers/acpi/Makefile | 1 +
> drivers/acpi/cmi_i2c.c | 391 ++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 403 insertions(+), 0 deletions(-)
> create mode 100644 drivers/acpi/cmi_i2c.c
>
> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> index 7ec7d88..ce7cf38 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -333,4 +333,15 @@ config ACPI_SBS
> To compile this driver as a module, choose M here:
> the modules will be called sbs and sbshc.
>
> +config ACPI_I2C
> + tristate "SMBus Control Method Interface"
> + depends on X86
> + help
> + This driver supports the SMBus Control Method Interface. It needs
> + BIOS declare ACPI control methods via SMBus Control Method Interface
> + Spec.
> +
> + To compile this driver as a module, choose M here:
> + the modules will be called sbs and sbshc.
> +
> endif # ACPI
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index 03a985b..a76c351 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -56,6 +56,7 @@ obj-$(CONFIG_ACPI_HOTPLUG_MEMORY) += acpi_memhotplug.o
> obj-$(CONFIG_ACPI_BATTERY) += battery.o
> obj-$(CONFIG_ACPI_SBS) += sbshc.o
> obj-$(CONFIG_ACPI_SBS) += sbs.o
> +obj-$(CONFIG_ACPI_I2C) += cmi_i2c.o
>
> # processor has its own "processor." module_param namespace
> processor-y := processor_core.o processor_throttling.o
> diff --git a/drivers/acpi/cmi_i2c.c b/drivers/acpi/cmi_i2c.c
> new file mode 100644
> index 0000000..69f3202
> --- /dev/null
> +++ b/drivers/acpi/cmi_i2c.c
> @@ -0,0 +1,391 @@
> +/*
> + * SMBus driver for ACPI SMBus CMI
> + *
> + * Copyright (C) 2009 Crane Cai <crane.cai@amd.com>
> + *
> + * 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 version 2.
> + */
> +
> +#include <linux/version.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/kernel.h>
> +#include <linux/stddef.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/acpi.h>
> +#include <linux/delay.h>
> +
> +#define ACPI_SMB_HC_COMPONENT 0x00080000
> +#define ACPI_SMB_HC_CLASS "smbus"
> +#define ACPI_SMB_HC_DEVICE_NAME "smbus cmi"
> +#define SMB_HC_DEVICE_NAME "SMBus CMI adapter"
> +
> +#define _COMPONENT ACPI_SMB_HC_COMPONENT
> +
> +ACPI_MODULE_NAME("smbus_cmi");
> +
> +struct smbus_methods {
> + char *mt_info;
> + char *mt_sbr;
> + char *mt_sbw;
> +};
> +
> +struct acpi_smbus_cmi {
> + acpi_handle handle;
> + struct i2c_adapter adapter;
> + struct smbus_methods *methods;
> +};
> +
> +static const struct smbus_methods smb_mtds = {
> + .mt_info = "_SBI",
> + .mt_sbr = "_SBR",
> + .mt_sbw = "_SBW",
> +};
> +
> +static const struct acpi_device_id i2c_device_ids[] = {
> + {"SMBUS01", 0},
> + {"", 0},
> +};
> +
> +static int acpi_smb_cmi_add(struct acpi_device *device);
> +static int acpi_smb_cmi_remove(struct acpi_device *device, int type);
> +
> +static struct acpi_driver acpi_smb_cmi_driver = {
> + .name = ACPI_SMB_HC_DEVICE_NAME,
> + .class = ACPI_SMB_HC_CLASS,
> + .ids = i2c_device_ids,
> + .ops = {
> + .add = acpi_smb_cmi_add,
> + .remove = acpi_smb_cmi_remove,
> + },
> +};
> +
> +#define ACPI_SMB_STATUS_OK 0x00
> +#define ACPI_SMB_STATUS_FAIL 0x07
> +#define ACPI_SMB_STATUS_DNAK 0x10
> +#define ACPI_SMB_STATUS_DERR 0x11
> +#define ACPI_SMB_STATUS_CMD_DENY 0x12
> +#define ACPI_SMB_STATUS_UNKNOWN 0x13
> +#define ACPI_SMB_STATUS_ACC_DENY 0x17
> +#define ACPI_SMB_STATUS_TIMEOUT 0x18
> +#define ACPI_SMB_STATUS_NOTSUP 0x19
> +#define ACPI_SMB_STATUS_BUSY 0x1A
> +#define ACPI_SMB_STATUS_PEC 0x1F
> +
> +#define ACPI_SMB_PRTCL_WRITE 0x0
> +#define ACPI_SMB_PRTCL_READ 0x01
> +#define ACPI_SMB_PRTCL_QUICK 0x02
> +#define ACPI_SMB_PRTCL_BYTE 0x04
> +#define ACPI_SMB_PRTCL_BYTE_DATA 0x06
> +#define ACPI_SMB_PRTCL_WORD_DATA 0x08
> +#define ACPI_SMB_PRTCL_BLOCK_DATA 0x0a
> +#define ACPI_SMB_PRTCL_PROC_CALL 0x0c
> +#define ACPI_SMB_PRTCL_BLOCK_PROC_CALL 0x0d
> +#define ACPI_SMB_PRTCL_PEC 0x80
> +
> +
> +static int
> +acpi_smb_cmi_access(struct i2c_adapter *adap, u16 addr, unsigned short flags,
> + char read_write, u8 command, int size,
> + union i2c_smbus_data *data)
> +{
> + int result = 0;
> + struct acpi_smbus_cmi *smbus_cmi = adap->algo_data;
> + unsigned char protocol, len = 0;
> + acpi_status status = 0;
> + struct acpi_object_list input;
> + union acpi_object mt_params[5];
> + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> + union acpi_object *obj;
> + union acpi_object *pkg;
> + char *mthd;
> +
> + switch (size) {
> + case I2C_SMBUS_QUICK:
> + protocol = ACPI_SMB_PRTCL_QUICK;
> + command = 0;
> + if (read_write == I2C_SMBUS_WRITE) {
> + mt_params[3].type = ACPI_TYPE_INTEGER;
> + mt_params[3].integer.value = 0;
> + mt_params[4].type = ACPI_TYPE_INTEGER;
> + mt_params[4].integer.value = 0;
> + }
> + break;
> +
> + case I2C_SMBUS_BYTE:
> + protocol = ACPI_SMB_PRTCL_BYTE;
> + if (read_write == I2C_SMBUS_WRITE) {
> + mt_params[3].type = ACPI_TYPE_INTEGER;
> + mt_params[3].integer.value = 0;
> + mt_params[4].type = ACPI_TYPE_INTEGER;
> + mt_params[4].integer.value = 0;
> + } else {
> + command = 0;
> + }
> + break;
> +
> + case I2C_SMBUS_BYTE_DATA:
> + protocol = ACPI_SMB_PRTCL_BYTE_DATA;
> + if (read_write == I2C_SMBUS_WRITE) {
> + mt_params[3].type = ACPI_TYPE_INTEGER;
> + mt_params[3].integer.value = 1;
> + mt_params[4].type = ACPI_TYPE_INTEGER;
> + mt_params[4].integer.value = data->byte;
> + }
> + break;
> +
> + case I2C_SMBUS_WORD_DATA:
> + protocol = ACPI_SMB_PRTCL_WORD_DATA;
> + if (read_write == I2C_SMBUS_WRITE) {
> + mt_params[3].type = ACPI_TYPE_INTEGER;
> + mt_params[3].integer.value = 2;
> + mt_params[4].type = ACPI_TYPE_INTEGER;
> + mt_params[4].integer.value = data->word;
> + }
> + break;
> +
> + case I2C_SMBUS_BLOCK_DATA:
> + protocol = ACPI_SMB_PRTCL_BLOCK_DATA;
> + if (read_write == I2C_SMBUS_WRITE) {
> + len = data->block[0];
> + if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
> + return -EINVAL;
> + mt_params[3].type = ACPI_TYPE_INTEGER;
> + mt_params[3].integer.value = len;
> + mt_params[4].type = ACPI_TYPE_BUFFER;
> + mt_params[4].buffer.pointer = data->block + 1;
> + }
> + break;
> +
> + default:
> + ACPI_DEBUG_PRINT((ACPI_DB_WARN, "SMBus CMI adapter: "
> + "Unsupported transaction %d\n", size));
> + return -EOPNOTSUPP;
> + }
> +
> + if (read_write == I2C_SMBUS_READ) {
> + protocol |= ACPI_SMB_PRTCL_READ;
> + mthd = smbus_cmi->methods->mt_sbr;
> + input.count = 3;
> + } else {
> + protocol |= ACPI_SMB_PRTCL_WRITE;
> + mthd = smbus_cmi->methods->mt_sbw;
> + input.count = 5;
> + }
> +
> + input.pointer = mt_params;
> + mt_params[0].type = ACPI_TYPE_INTEGER;
> + mt_params[0].integer.value = protocol;
> + mt_params[1].type = ACPI_TYPE_INTEGER;
> + mt_params[1].integer.value = addr;
> + mt_params[2].type = ACPI_TYPE_INTEGER;
> + mt_params[2].integer.value = command;
> +
> + status = acpi_evaluate_object(smbus_cmi->handle, mthd, &input, &buffer);
> + if (ACPI_FAILURE(status)) {
> + ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Error evaluate %s\n", mthd));
> + return -EIO;
> + }
> +
> + pkg = buffer.pointer;
> + if (pkg && pkg->type == ACPI_TYPE_PACKAGE)
> + obj = pkg->package.elements;
> + else {
> + result = -EIO;
> + goto out;
> + }
> + if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) {
> + ACPI_DEBUG_PRINT((ACPI_DB_WARN, "SMBus status object type \
> + error\n"));
> + result = -EIO;
> + goto out;
> + }
> +
> + result = obj->integer.value;
> + switch (result) {
> + case ACPI_SMB_STATUS_OK:
> + break;
> + case ACPI_SMB_STATUS_BUSY:
> + result = -EBUSY;
> + goto out;
> + case ACPI_SMB_STATUS_TIMEOUT:
> + result = -ETIMEDOUT;
> + goto out;
> + case ACPI_SMB_STATUS_DNAK:
> + result = -ENXIO;
> + goto out;
> + default:
> + result = -EIO;
> + goto out;
> + }
> +
> + if (read_write == I2C_SMBUS_WRITE)
> + goto out;
> +
> + obj = pkg->package.elements + 1;
> + if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) {
> + ACPI_DEBUG_PRINT((ACPI_DB_WARN, "SMBus return package object \
> + type error\n"));
> + result = -EIO;
> + goto out;
> + }
> +
> + len = obj->integer.value;
> + obj = pkg->package.elements + 2;
> + switch (size) {
> + case I2C_SMBUS_BYTE:
> + case I2C_SMBUS_BYTE_DATA:
> + case I2C_SMBUS_WORD_DATA:
> + if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) {
> + ACPI_DEBUG_PRINT((ACPI_DB_WARN, "SMBus return package \
> + object type error\n"));
> + result = -EIO;
> + goto out;
> + }
> + if (len == 2)
> + data->word = obj->integer.value & 0xffff;
> + else
> + data->byte = obj->integer.value & 0xff;
> + break;
> + case I2C_SMBUS_BLOCK_DATA:
> + if (obj == NULL || obj->type != ACPI_TYPE_BUFFER) {
> + ACPI_DEBUG_PRINT((ACPI_DB_WARN, "SMBus return package \
> + object type error\n"));
> + result = -EIO;
> + goto out;
> + }
> + data->block[0] = len;
> + if (data->block[0] == 0 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
> + return -EPROTO;
> + memcpy(data->block + 1, obj->buffer.pointer, len);
> + break;
> + }
> +
> +out:
> + kfree(buffer.pointer);
> + return result;
> +}
> +
> +static u32 acpi_smb_cmi_func(struct i2c_adapter *adapter)
> +{
> +
> + return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
> + I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
> + I2C_FUNC_SMBUS_BLOCK_DATA;
> +}
> +
> +static const struct i2c_algorithm acpi_smbus_cmi_algorithm = {
> + .smbus_xfer = acpi_smb_cmi_access,
> + .functionality = acpi_smb_cmi_func,
> +};
> +
> +static int acpi_smb_cmi_add(struct acpi_device *device)
> +{
> + int status;
> + struct acpi_smbus_cmi *smb_cmi;
> + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> + union acpi_object *obj;
> +
> + if (!device)
> + return -EINVAL;
> +
> + smb_cmi = kzalloc(sizeof(struct acpi_smbus_cmi), GFP_KERNEL);
> + if (!smb_cmi)
> + return -ENOMEM;
> +
> + smb_cmi->handle = device->handle;
> + strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
> + strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
> + device->driver_data = smb_cmi;
> + smb_cmi->methods = (struct smbus_methods *)(&smb_mtds);
> +
> + status = acpi_evaluate_object(smb_cmi->handle,
> + smb_cmi->methods->mt_info,
> + NULL, &buffer);
> + if (ACPI_FAILURE(status)) {
> + ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Error obtaining _SBI\n"));
> + goto err;
> + }
> +
> + obj = buffer.pointer;
> + if (obj && obj->type == ACPI_TYPE_PACKAGE)
> + obj = obj->package.elements;
> + else {
> + kfree(buffer.pointer);
> + goto err;
> + }
> +
> + if (obj->type != ACPI_TYPE_INTEGER) {
> + ACPI_DEBUG_PRINT((ACPI_DB_WARN, "SMBus CMI Version object type \
> + error\n"));
> + } else
> + ACPI_DEBUG_PRINT((ACPI_DB_WARN, "SMBus CMI Version %0x\n",
> + (int)obj->integer.value));
> + kfree(buffer.pointer);
> +
> + snprintf(smb_cmi->adapter.name, sizeof(smb_cmi->adapter.name),
> + "SMBus CMI adapter");
> + smb_cmi->adapter.owner = THIS_MODULE;
> + smb_cmi->adapter.algo = &acpi_smbus_cmi_algorithm;
> + smb_cmi->adapter.algo_data = smb_cmi;
> + smb_cmi->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
> + smb_cmi->adapter.dev.parent = &device->dev;
> +
> + if (i2c_add_adapter(&smb_cmi->adapter)) {
> + ACPI_DEBUG_PRINT((ACPI_DB_WARN,
> + "SMBus CMI adapter: Failed to register adapter\n"));
> + kfree(smb_cmi);
> + return -EIO;
> + }
> +
> + printk(KERN_INFO PREFIX "%s [%s]\n",
> + acpi_device_name(device), acpi_device_bid(device));
> +
> + return AE_OK;
> +
> +err:
> + kfree(smb_cmi);
> + device->driver_data = NULL;
> + return -EIO;
> +}
> +
> +static int acpi_smb_cmi_remove(struct acpi_device *device, int type)
> +{
> + struct acpi_smbus_cmi *smbus_cmi;
> +
> + if (!device)
> + return -EINVAL;
> +
> + smbus_cmi = acpi_driver_data(device);
> +
> + i2c_del_adapter(&smbus_cmi->adapter);
> + kfree(smbus_cmi);
> +
> + return AE_OK;
> +}
> +
> +static int __init acpi_smb_cmi_init(void)
> +{
> + int result;
> +
> + result = acpi_bus_register_driver(&acpi_smb_cmi_driver);
> + if (result < 0)
> + return -ENODEV;
> +
> + return 0;
> +}
> +
> +static void __exit acpi_smb_cmi_exit(void)
> +{
> + acpi_bus_unregister_driver(&acpi_smb_cmi_driver);
> +}
> +
> +module_init(acpi_smb_cmi_init);
> +module_exit(acpi_smb_cmi_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Crane Cai");
> +MODULE_DESCRIPTION("ACPI SMBus CMI driver");
> --
> 1.6.0.4
>
> --
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