diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/i2c/busses/i2c-scmi.c | 429 |
1 files changed, 429 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-scmi.c b/drivers/i2c/busses/i2c-scmi.c new file mode 100644 index 000000000..0239e134b --- /dev/null +++ b/drivers/i2c/busses/i2c-scmi.c @@ -0,0 +1,429 @@ +// 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 int 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); + + return 0; +} + +static struct platform_driver smbus_cmi_driver = { + .probe = smbus_cmi_probe, + .remove = 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"); |