| /* |
| * SMBus driver for ACPI Embedded Controller (v0.1) |
| * |
| * Copyright (c) 2007 Alexey Starikovskiy |
| * |
| * 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 <acpi/acpi_bus.h> |
| #include <acpi/acpi_drivers.h> |
| #include <linux/wait.h> |
| #include <linux/slab.h> |
| #include <linux/delay.h> |
| #include <linux/module.h> |
| #include <linux/interrupt.h> |
| #include "sbshc.h" |
| |
| #define PREFIX "ACPI: " |
| |
| #define ACPI_SMB_HC_CLASS "smbus_host_ctl" |
| #define ACPI_SMB_HC_DEVICE_NAME "ACPI SMBus HC" |
| |
| struct acpi_smb_hc { |
| struct acpi_ec *ec; |
| struct mutex lock; |
| wait_queue_head_t wait; |
| u8 offset; |
| u8 query_bit; |
| smbus_alarm_callback callback; |
| void *context; |
| }; |
| |
| static int acpi_smbus_hc_add(struct acpi_device *device); |
| static int acpi_smbus_hc_remove(struct acpi_device *device, int type); |
| |
| static const struct acpi_device_id sbs_device_ids[] = { |
| {"ACPI0001", 0}, |
| {"ACPI0005", 0}, |
| {"", 0}, |
| }; |
| |
| MODULE_DEVICE_TABLE(acpi, sbs_device_ids); |
| |
| static struct acpi_driver acpi_smb_hc_driver = { |
| .name = "smbus_hc", |
| .class = ACPI_SMB_HC_CLASS, |
| .ids = sbs_device_ids, |
| .ops = { |
| .add = acpi_smbus_hc_add, |
| .remove = acpi_smbus_hc_remove, |
| }, |
| }; |
| |
| union acpi_smb_status { |
| u8 raw; |
| struct { |
| u8 status:5; |
| u8 reserved:1; |
| u8 alarm:1; |
| u8 done:1; |
| } fields; |
| }; |
| |
| enum acpi_smb_status_codes { |
| SMBUS_OK = 0, |
| SMBUS_UNKNOWN_FAILURE = 0x07, |
| SMBUS_DEVICE_ADDRESS_NACK = 0x10, |
| SMBUS_DEVICE_ERROR = 0x11, |
| SMBUS_DEVICE_COMMAND_ACCESS_DENIED = 0x12, |
| SMBUS_UNKNOWN_ERROR = 0x13, |
| SMBUS_DEVICE_ACCESS_DENIED = 0x17, |
| SMBUS_TIMEOUT = 0x18, |
| SMBUS_HOST_UNSUPPORTED_PROTOCOL = 0x19, |
| SMBUS_BUSY = 0x1a, |
| SMBUS_PEC_ERROR = 0x1f, |
| }; |
| |
| enum acpi_smb_offset { |
| ACPI_SMB_PROTOCOL = 0, /* protocol, PEC */ |
| ACPI_SMB_STATUS = 1, /* status */ |
| ACPI_SMB_ADDRESS = 2, /* address */ |
| ACPI_SMB_COMMAND = 3, /* command */ |
| ACPI_SMB_DATA = 4, /* 32 data registers */ |
| ACPI_SMB_BLOCK_COUNT = 0x24, /* number of data bytes */ |
| ACPI_SMB_ALARM_ADDRESS = 0x25, /* alarm address */ |
| ACPI_SMB_ALARM_DATA = 0x26, /* 2 bytes alarm data */ |
| }; |
| |
| static inline int smb_hc_read(struct acpi_smb_hc *hc, u8 address, u8 *data) |
| { |
| return ec_read(hc->offset + address, data); |
| } |
| |
| static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data) |
| { |
| return ec_write(hc->offset + address, data); |
| } |
| |
| static inline int smb_check_done(struct acpi_smb_hc *hc) |
| { |
| union acpi_smb_status status = {.raw = 0}; |
| smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw); |
| return status.fields.done && (status.fields.status == SMBUS_OK); |
| } |
| |
| static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout) |
| { |
| if (wait_event_timeout(hc->wait, smb_check_done(hc), |
| msecs_to_jiffies(timeout))) |
| return 0; |
| /* |
| * After the timeout happens, OS will try to check the status of SMbus. |
| * If the status is what OS expected, it will be regarded as the bogus |
| * timeout. |
| */ |
| if (smb_check_done(hc)) |
| return 0; |
| else |
| return -ETIME; |
| } |
| |
| static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol, |
| u8 address, u8 command, u8 *data, u8 length) |
| { |
| int ret = -EFAULT, i; |
| u8 temp, sz = 0; |
| |
| if (!hc) { |
| printk(KERN_ERR PREFIX "host controller is not configured\n"); |
| return ret; |
| } |
| |
| mutex_lock(&hc->lock); |
| if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp)) |
| goto end; |
| if (temp) { |
| ret = -EBUSY; |
| goto end; |
| } |
| smb_hc_write(hc, ACPI_SMB_COMMAND, command); |
| if (!(protocol & 0x01)) { |
| smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length); |
| for (i = 0; i < length; ++i) |
| smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]); |
| } |
| smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1); |
| smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol); |
| /* |
| * Wait for completion. Save the status code, data size, |
| * and data into the return package (if required by the protocol). |
| */ |
| ret = wait_transaction_complete(hc, 1000); |
| if (ret || !(protocol & 0x01)) |
| goto end; |
| switch (protocol) { |
| case SMBUS_RECEIVE_BYTE: |
| case SMBUS_READ_BYTE: |
| sz = 1; |
| break; |
| case SMBUS_READ_WORD: |
| sz = 2; |
| break; |
| case SMBUS_READ_BLOCK: |
| if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) { |
| ret = -EFAULT; |
| goto end; |
| } |
| sz &= 0x1f; |
| break; |
| } |
| for (i = 0; i < sz; ++i) |
| smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]); |
| end: |
| mutex_unlock(&hc->lock); |
| return ret; |
| } |
| |
| int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address, |
| u8 command, u8 *data) |
| { |
| return acpi_smbus_transaction(hc, protocol, address, command, data, 0); |
| } |
| |
| EXPORT_SYMBOL_GPL(acpi_smbus_read); |
| |
| int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address, |
| u8 command, u8 *data, u8 length) |
| { |
| return acpi_smbus_transaction(hc, protocol, address, command, data, length); |
| } |
| |
| EXPORT_SYMBOL_GPL(acpi_smbus_write); |
| |
| int acpi_smbus_register_callback(struct acpi_smb_hc *hc, |
| smbus_alarm_callback callback, void *context) |
| { |
| mutex_lock(&hc->lock); |
| hc->callback = callback; |
| hc->context = context; |
| mutex_unlock(&hc->lock); |
| return 0; |
| } |
| |
| EXPORT_SYMBOL_GPL(acpi_smbus_register_callback); |
| |
| int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc) |
| { |
| mutex_lock(&hc->lock); |
| hc->callback = NULL; |
| hc->context = NULL; |
| mutex_unlock(&hc->lock); |
| return 0; |
| } |
| |
| EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback); |
| |
| static inline void acpi_smbus_callback(void *context) |
| { |
| struct acpi_smb_hc *hc = context; |
| if (hc->callback) |
| hc->callback(hc->context); |
| } |
| |
| static int smbus_alarm(void *context) |
| { |
| struct acpi_smb_hc *hc = context; |
| union acpi_smb_status status; |
| u8 address; |
| if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw)) |
| return 0; |
| /* Check if it is only a completion notify */ |
| if (status.fields.done) |
| wake_up(&hc->wait); |
| if (!status.fields.alarm) |
| return 0; |
| mutex_lock(&hc->lock); |
| smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address); |
| status.fields.alarm = 0; |
| smb_hc_write(hc, ACPI_SMB_STATUS, status.raw); |
| /* We are only interested in events coming from known devices */ |
| switch (address >> 1) { |
| case ACPI_SBS_CHARGER: |
| case ACPI_SBS_MANAGER: |
| case ACPI_SBS_BATTERY: |
| acpi_os_execute(OSL_NOTIFY_HANDLER, |
| acpi_smbus_callback, hc); |
| default:; |
| } |
| mutex_unlock(&hc->lock); |
| return 0; |
| } |
| |
| typedef int (*acpi_ec_query_func) (void *data); |
| |
| extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit, |
| acpi_handle handle, acpi_ec_query_func func, |
| void *data); |
| |
| static int acpi_smbus_hc_add(struct acpi_device *device) |
| { |
| int status; |
| unsigned long long val; |
| struct acpi_smb_hc *hc; |
| |
| if (!device) |
| return -EINVAL; |
| |
| status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val); |
| if (ACPI_FAILURE(status)) { |
| printk(KERN_ERR PREFIX "error obtaining _EC.\n"); |
| return -EIO; |
| } |
| |
| strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME); |
| strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS); |
| |
| hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL); |
| if (!hc) |
| return -ENOMEM; |
| mutex_init(&hc->lock); |
| init_waitqueue_head(&hc->wait); |
| |
| hc->ec = acpi_driver_data(device->parent); |
| hc->offset = (val >> 8) & 0xff; |
| hc->query_bit = val & 0xff; |
| device->driver_data = hc; |
| |
| acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc); |
| printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n", |
| hc->ec, hc->offset, hc->query_bit); |
| |
| return 0; |
| } |
| |
| extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit); |
| |
| static int acpi_smbus_hc_remove(struct acpi_device *device, int type) |
| { |
| struct acpi_smb_hc *hc; |
| |
| if (!device) |
| return -EINVAL; |
| |
| hc = acpi_driver_data(device); |
| acpi_ec_remove_query_handler(hc->ec, hc->query_bit); |
| kfree(hc); |
| device->driver_data = NULL; |
| return 0; |
| } |
| |
| static int __init acpi_smb_hc_init(void) |
| { |
| int result; |
| |
| result = acpi_bus_register_driver(&acpi_smb_hc_driver); |
| if (result < 0) |
| return -ENODEV; |
| return 0; |
| } |
| |
| static void __exit acpi_smb_hc_exit(void) |
| { |
| acpi_bus_unregister_driver(&acpi_smb_hc_driver); |
| } |
| |
| module_init(acpi_smb_hc_init); |
| module_exit(acpi_smb_hc_exit); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Alexey Starikovskiy"); |
| MODULE_DESCRIPTION("ACPI SMBus HC driver"); |