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linux/drivers/i2c/busses/i2c-scmi.c
Uwe Kleine-König e190a0c389 i2c: Convert to platform remove callback returning void 
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Jochen Friedrich <jochen@scram.de>
Acked-by: Peter Rosin <peda@axentia.se>
Acked-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Asmaa Mnebhi <asnaa@nvidia.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Chris Pringle <chris.pringle@phabrix.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Tali Perry <tali.perry@nuvoton.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-06-05 09:47:37 +02:00

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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>
/* SMBUS HID definition as supported by Microsoft Windows */
#define ACPI_SMBUS_MS_HID "SMB0001"
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 | I2C_CLASS_SPD;
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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