diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-scmi.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-scmi.c | 430 |
1 files changed, 430 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-scmi.c b/drivers/i2c/busses/i2c-scmi.c new file mode 100644 index 000000000000..276a046ac93f --- /dev/null +++ b/drivers/i2c/busses/i2c-scmi.c @@ -0,0 +1,430 @@ +/* + * 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/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> + +#define ACPI_SMBUS_HC_CLASS "smbus" +#define ACPI_SMBUS_HC_DEVICE_NAME "cmi" + +ACPI_MODULE_NAME("smbus_cmi"); + +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; +}; + +static const struct smbus_methods_t smbus_methods = { + .mt_info = "_SBI", + .mt_sbr = "_SBR", + .mt_sbw = "_SBW", +}; + +static const struct acpi_device_id acpi_smbus_cmi_ids[] = { + {"SMBUS01", 0}, + {"", 0} +}; + +#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.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_methods.mt_sbr; + input.count = 3; + } else { + protocol |= ACPI_SMBUS_PRTCL_WRITE; + method = smbus_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_ERROR((AE_INFO, "Evaluating %s: %i", method, status)); + return -EIO; + } + + pkg = buffer.pointer; + if (pkg && pkg->type == ACPI_TYPE_PACKAGE) + obj = pkg->package.elements; + else { + ACPI_ERROR((AE_INFO, "Invalid argument type")); + result = -EIO; + goto out; + } + if (obj == NULL || obj->type != ACPI_TYPE_INTEGER) { + ACPI_ERROR((AE_INFO, "Invalid argument type")); + result = -EIO; + goto out; + } + + result = obj->integer.value; + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "%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 == NULL || obj->type != ACPI_TYPE_INTEGER) { + ACPI_ERROR((AE_INFO, "Invalid argument type")); + 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_ERROR((AE_INFO, "Invalid argument type")); + 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 == NULL || obj->type != ACPI_TYPE_BUFFER) { + ACPI_ERROR((AE_INFO, "Invalid argument type")); + 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 }; + union acpi_object *obj; + acpi_status status; + + if (!strcmp(name, smbus_methods.mt_info)) { + status = acpi_evaluate_object(smbus_cmi->handle, + smbus_methods.mt_info, + NULL, &buffer); + if (ACPI_FAILURE(status)) { + ACPI_ERROR((AE_INFO, "Evaluating %s: %i", + smbus_methods.mt_info, status)); + return -EIO; + } + + obj = buffer.pointer; + if (obj && obj->type == ACPI_TYPE_PACKAGE) + obj = obj->package.elements; + else { + ACPI_ERROR((AE_INFO, "Invalid argument type")); + kfree(buffer.pointer); + return -EIO; + } + + if (obj->type != ACPI_TYPE_INTEGER) { + ACPI_ERROR((AE_INFO, "Invalid argument type")); + kfree(buffer.pointer); + return -EIO; + } else + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "SMBus CMI Version %x" + "\n", (int)obj->integer.value)); + + kfree(buffer.pointer); + smbus_cmi->cap_info = 1; + } else if (!strcmp(name, smbus_methods.mt_sbr)) + smbus_cmi->cap_read = 1; + else if (!strcmp(name, smbus_methods.mt_sbw)) + smbus_cmi->cap_write = 1; + else + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "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 acpi_smbus_cmi_add(struct acpi_device *device) +{ + struct acpi_smbus_cmi *smbus_cmi; + + smbus_cmi = kzalloc(sizeof(struct acpi_smbus_cmi), GFP_KERNEL); + if (!smbus_cmi) + return -ENOMEM; + + smbus_cmi->handle = device->handle; + strcpy(acpi_device_name(device), ACPI_SMBUS_HC_DEVICE_NAME); + strcpy(acpi_device_class(device), ACPI_SMBUS_HC_CLASS); + device->driver_data = 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, smbus_cmi, NULL); + + if (smbus_cmi->cap_info == 0) + goto err; + + snprintf(smbus_cmi->adapter.name, sizeof(smbus_cmi->adapter.name), + "SMBus CMI adapter %s (%s)", + acpi_device_name(device), + acpi_device_uid(device)); + 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; + + if (i2c_add_adapter(&smbus_cmi->adapter)) { + dev_err(&device->dev, "Couldn't register adapter!\n"); + goto err; + } + + return 0; + +err: + kfree(smbus_cmi); + device->driver_data = NULL; + return -EIO; +} + +static int acpi_smbus_cmi_remove(struct acpi_device *device, int type) +{ + struct acpi_smbus_cmi *smbus_cmi = acpi_driver_data(device); + + i2c_del_adapter(&smbus_cmi->adapter); + kfree(smbus_cmi); + device->driver_data = NULL; + + return 0; +} + +static struct acpi_driver acpi_smbus_cmi_driver = { + .name = ACPI_SMBUS_HC_DEVICE_NAME, + .class = ACPI_SMBUS_HC_CLASS, + .ids = acpi_smbus_cmi_ids, + .ops = { + .add = acpi_smbus_cmi_add, + .remove = acpi_smbus_cmi_remove, + }, +}; + +static int __init acpi_smbus_cmi_init(void) +{ + return acpi_bus_register_driver(&acpi_smbus_cmi_driver); +} + +static void __exit acpi_smbus_cmi_exit(void) +{ + acpi_bus_unregister_driver(&acpi_smbus_cmi_driver); +} + +module_init(acpi_smbus_cmi_init); +module_exit(acpi_smbus_cmi_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Crane Cai <crane.cai@amd.com>"); +MODULE_DESCRIPTION("ACPI SMBus CMI driver"); |