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linux/drivers/i2c/busses/i2c-scmi.c
Heiner Kallweit 9fd12f3857 i2c: Don't let i2c adapters declare I2C_CLASS_SPD support if they support I2C_CLASS_HWMON 
After removal of the legacy eeprom driver the only remaining I2C
client device driver supporting I2C_CLASS_SPD is jc42. Because this
driver also supports I2C_CLASS_HWMON, adapters don't have to
declare support for I2C_CLASS_SPD if they support I2C_CLASS_HWMON.
It's one step towards getting rid of I2C_CLASS_SPD mid-term.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Acked-by: Jim Cromie <jim.cromie@gmail.com> # for SCX
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2024-01-18 21:10:41 +01:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* SMBus driver for ACPI SMBus CMI
*
* Copyright (C) 2009 Crane Cai <crane.cai@amd.com>
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/stddef.h>
#include <linux/i2c.h>
#include <linux/acpi.h>
struct smbus_methods_t {
char *mt_info;
char *mt_sbr;
char *mt_sbw;
};
struct acpi_smbus_cmi {
acpi_handle handle;
struct i2c_adapter adapter;
u8 cap_info:1;
u8 cap_read:1;
u8 cap_write:1;
const struct smbus_methods_t *methods;
};
static const struct smbus_methods_t smbus_methods = {
.mt_info = "_SBI",
.mt_sbr = "_SBR",
.mt_sbw = "_SBW",
};
/* Some IBM BIOSes omit the leading underscore */
static const struct smbus_methods_t ibm_smbus_methods = {
.mt_info = "SBI_",
.mt_sbr = "SBR_",
.mt_sbw = "SBW_",
};
static const struct acpi_device_id acpi_smbus_cmi_ids[] = {
{"SMBUS01", (kernel_ulong_t)&smbus_methods},
{ACPI_SMBUS_IBM_HID, (kernel_ulong_t)&ibm_smbus_methods},
{ACPI_SMBUS_MS_HID, (kernel_ulong_t)&smbus_methods},
{"", 0}
};
MODULE_DEVICE_TABLE(acpi, acpi_smbus_cmi_ids);
#define ACPI_SMBUS_STATUS_OK 0x00
#define ACPI_SMBUS_STATUS_FAIL 0x07
#define ACPI_SMBUS_STATUS_DNAK 0x10
#define ACPI_SMBUS_STATUS_DERR 0x11
#define ACPI_SMBUS_STATUS_CMD_DENY 0x12
#define ACPI_SMBUS_STATUS_UNKNOWN 0x13
#define ACPI_SMBUS_STATUS_ACC_DENY 0x17
#define ACPI_SMBUS_STATUS_TIMEOUT 0x18
#define ACPI_SMBUS_STATUS_NOTSUP 0x19
#define ACPI_SMBUS_STATUS_BUSY 0x1a
#define ACPI_SMBUS_STATUS_PEC 0x1f
#define ACPI_SMBUS_PRTCL_WRITE 0x00
#define ACPI_SMBUS_PRTCL_READ 0x01
#define ACPI_SMBUS_PRTCL_QUICK 0x02
#define ACPI_SMBUS_PRTCL_BYTE 0x04
#define ACPI_SMBUS_PRTCL_BYTE_DATA 0x06
#define ACPI_SMBUS_PRTCL_WORD_DATA 0x08
#define ACPI_SMBUS_PRTCL_BLOCK_DATA 0x0a
static int
acpi_smbus_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;
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 *method;
int len = 0;
dev_dbg(&adap->dev, "access size: %d %s\n", size,
(read_write) ? "READ" : "WRITE");
switch (size) {
case I2C_SMBUS_QUICK:
protocol = ACPI_SMBUS_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_SMBUS_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_SMBUS_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_SMBUS_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_SMBUS_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.length = len;
mt_params[4].buffer.pointer = data->block + 1;
}
break;
default:
dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
return -EOPNOTSUPP;
}
if (read_write == I2C_SMBUS_READ) {
protocol |= ACPI_SMBUS_PRTCL_READ;
method = smbus_cmi->methods->mt_sbr;
input.count = 3;
} else {
protocol |= ACPI_SMBUS_PRTCL_WRITE;
method = 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, method, &input,
&buffer);
if (ACPI_FAILURE(status)) {
acpi_handle_err(smbus_cmi->handle,
"Failed to evaluate %s: %i\n", method, status);
return -EIO;
}
pkg = buffer.pointer;
if (pkg && pkg->type == ACPI_TYPE_PACKAGE)
obj = pkg->package.elements;
else {
acpi_handle_err(smbus_cmi->handle, "Invalid argument type\n");
result = -EIO;
goto out;
}
if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) {
acpi_handle_err(smbus_cmi->handle, "Invalid argument type\n");
result = -EIO;
goto out;
}
result = obj->integer.value;
acpi_handle_debug(smbus_cmi->handle, "%s return status: %i\n", method,
result);
switch (result) {
case ACPI_SMBUS_STATUS_OK:
result = 0;
break;
case ACPI_SMBUS_STATUS_BUSY:
result = -EBUSY;
goto out;
case ACPI_SMBUS_STATUS_TIMEOUT:
result = -ETIMEDOUT;
goto out;
case ACPI_SMBUS_STATUS_DNAK:
result = -ENXIO;
goto out;
default:
result = -EIO;
goto out;
}
if (read_write == I2C_SMBUS_WRITE || size == I2C_SMBUS_QUICK)
goto out;
obj = pkg->package.elements + 1;
if (obj->type != ACPI_TYPE_INTEGER) {
acpi_handle_err(smbus_cmi->handle, "Invalid argument type\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->type != ACPI_TYPE_INTEGER) {
acpi_handle_err(smbus_cmi->handle,
"Invalid argument type\n");
result = -EIO;
goto out;
}
if (len == 2)
data->word = obj->integer.value;
else
data->byte = obj->integer.value;
break;
case I2C_SMBUS_BLOCK_DATA:
if (obj->type != ACPI_TYPE_BUFFER) {
acpi_handle_err(smbus_cmi->handle,
"Invalid argument type\n");
result = -EIO;
goto out;
}
if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
return -EPROTO;
data->block[0] = len;
memcpy(data->block + 1, obj->buffer.pointer, len);
break;
}
out:
kfree(buffer.pointer);
dev_dbg(&adap->dev, "Transaction status: %i\n", result);
return result;
}
static u32 acpi_smbus_cmi_func(struct i2c_adapter *adapter)
{
struct acpi_smbus_cmi *smbus_cmi = adapter->algo_data;
u32 ret;
ret = smbus_cmi->cap_read | smbus_cmi->cap_write ?
I2C_FUNC_SMBUS_QUICK : 0;
ret |= smbus_cmi->cap_read ?
(I2C_FUNC_SMBUS_READ_BYTE |
I2C_FUNC_SMBUS_READ_BYTE_DATA |
I2C_FUNC_SMBUS_READ_WORD_DATA |
I2C_FUNC_SMBUS_READ_BLOCK_DATA) : 0;
ret |= smbus_cmi->cap_write ?
(I2C_FUNC_SMBUS_WRITE_BYTE |
I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
I2C_FUNC_SMBUS_WRITE_WORD_DATA |
I2C_FUNC_SMBUS_WRITE_BLOCK_DATA) : 0;
return ret;
}
static const struct i2c_algorithm acpi_smbus_cmi_algorithm = {
.smbus_xfer = acpi_smbus_cmi_access,
.functionality = acpi_smbus_cmi_func,
};
static int acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi *smbus_cmi,
const char *name)
{
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
struct acpi_handle *handle = smbus_cmi->handle;
union acpi_object *obj;
acpi_status status;
if (!strcmp(name, smbus_cmi->methods->mt_info)) {
status = acpi_evaluate_object(smbus_cmi->handle,
smbus_cmi->methods->mt_info,
NULL, &buffer);
if (ACPI_FAILURE(status)) {
acpi_handle_err(handle, "Failed to evaluate %s: %i\n",
smbus_cmi->methods->mt_info, status);
return -EIO;
}
obj = buffer.pointer;
if (obj && obj->type == ACPI_TYPE_PACKAGE)
obj = obj->package.elements;
else {
acpi_handle_err(handle, "Invalid argument type\n");
kfree(buffer.pointer);
return -EIO;
}
if (obj->type != ACPI_TYPE_INTEGER) {
acpi_handle_err(handle, "Invalid argument type\n");
kfree(buffer.pointer);
return -EIO;
} else
acpi_handle_debug(handle, "SMBus CMI Version %x\n",
(int)obj->integer.value);
kfree(buffer.pointer);
smbus_cmi->cap_info = 1;
} else if (!strcmp(name, smbus_cmi->methods->mt_sbr))
smbus_cmi->cap_read = 1;
else if (!strcmp(name, smbus_cmi->methods->mt_sbw))
smbus_cmi->cap_write = 1;
else
acpi_handle_debug(handle, "Unsupported CMI method: %s\n", name);
return 0;
}
static acpi_status acpi_smbus_cmi_query_methods(acpi_handle handle, u32 level,
void *context, void **return_value)
{
char node_name[5];
struct acpi_buffer buffer = { sizeof(node_name), node_name };
struct acpi_smbus_cmi *smbus_cmi = context;
acpi_status status;
status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
if (ACPI_SUCCESS(status))
acpi_smbus_cmi_add_cap(smbus_cmi, node_name);
return AE_OK;
}
static int smbus_cmi_probe(struct platform_device *device)
{
struct device *dev = &device->dev;
struct acpi_smbus_cmi *smbus_cmi;
int ret;
smbus_cmi = kzalloc(sizeof(struct acpi_smbus_cmi), GFP_KERNEL);
if (!smbus_cmi)
return -ENOMEM;
smbus_cmi->handle = ACPI_HANDLE(dev);
smbus_cmi->methods = device_get_match_data(dev);
platform_set_drvdata(device, smbus_cmi);
smbus_cmi->cap_info = 0;
smbus_cmi->cap_read = 0;
smbus_cmi->cap_write = 0;
acpi_walk_namespace(ACPI_TYPE_METHOD, smbus_cmi->handle, 1,
acpi_smbus_cmi_query_methods, NULL, smbus_cmi, NULL);
if (smbus_cmi->cap_info == 0) {
ret = -ENODEV;
goto err;
}
snprintf(smbus_cmi->adapter.name, sizeof(smbus_cmi->adapter.name),
"SMBus CMI adapter %s", dev_name(dev));
smbus_cmi->adapter.owner = THIS_MODULE;
smbus_cmi->adapter.algo = &acpi_smbus_cmi_algorithm;
smbus_cmi->adapter.algo_data = smbus_cmi;
smbus_cmi->adapter.class = I2C_CLASS_HWMON;
smbus_cmi->adapter.dev.parent = &device->dev;
ret = i2c_add_adapter(&smbus_cmi->adapter);
if (ret) {
dev_err(&device->dev, "Couldn't register adapter!\n");
goto err;
}
return 0;
err:
kfree(smbus_cmi);
return ret;
}
static void smbus_cmi_remove(struct platform_device *device)
{
struct acpi_smbus_cmi *smbus_cmi = platform_get_drvdata(device);
i2c_del_adapter(&smbus_cmi->adapter);
kfree(smbus_cmi);
}
static struct platform_driver smbus_cmi_driver = {
.probe = smbus_cmi_probe,
.remove_new = smbus_cmi_remove,
.driver = {
.name = "smbus_cmi",
.acpi_match_table = acpi_smbus_cmi_ids,
},
};
module_platform_driver(smbus_cmi_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Crane Cai <crane.cai@amd.com>");
MODULE_DESCRIPTION("ACPI SMBus CMI driver");
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