2 * SMBus driver for ACPI Embedded Controller (v0.1)
4 * Copyright (c) 2007 Alexey Starikovskiy
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation version 2.
11 #include <linux/acpi.h>
12 #include <linux/wait.h>
13 #include <linux/slab.h>
14 #include <linux/delay.h>
15 #include <linux/module.h>
16 #include <linux/interrupt.h>
17 #include <linux/dmi.h>
20 #define PREFIX "ACPI: "
22 #define ACPI_SMB_HC_CLASS "smbus_host_ctl"
23 #define ACPI_SMB_HC_DEVICE_NAME "ACPI SMBus HC"
28 wait_queue_head_t wait;
31 smbus_alarm_callback callback;
36 static int acpi_smbus_hc_add(struct acpi_device *device);
37 static int acpi_smbus_hc_remove(struct acpi_device *device);
39 static const struct acpi_device_id sbs_device_ids[] = {
45 MODULE_DEVICE_TABLE(acpi, sbs_device_ids);
47 static struct acpi_driver acpi_smb_hc_driver = {
49 .class = ACPI_SMB_HC_CLASS,
50 .ids = sbs_device_ids,
52 .add = acpi_smbus_hc_add,
53 .remove = acpi_smbus_hc_remove,
57 union acpi_smb_status {
67 enum acpi_smb_status_codes {
69 SMBUS_UNKNOWN_FAILURE = 0x07,
70 SMBUS_DEVICE_ADDRESS_NACK = 0x10,
71 SMBUS_DEVICE_ERROR = 0x11,
72 SMBUS_DEVICE_COMMAND_ACCESS_DENIED = 0x12,
73 SMBUS_UNKNOWN_ERROR = 0x13,
74 SMBUS_DEVICE_ACCESS_DENIED = 0x17,
76 SMBUS_HOST_UNSUPPORTED_PROTOCOL = 0x19,
78 SMBUS_PEC_ERROR = 0x1f,
81 enum acpi_smb_offset {
82 ACPI_SMB_PROTOCOL = 0, /* protocol, PEC */
83 ACPI_SMB_STATUS = 1, /* status */
84 ACPI_SMB_ADDRESS = 2, /* address */
85 ACPI_SMB_COMMAND = 3, /* command */
86 ACPI_SMB_DATA = 4, /* 32 data registers */
87 ACPI_SMB_BLOCK_COUNT = 0x24, /* number of data bytes */
88 ACPI_SMB_ALARM_ADDRESS = 0x25, /* alarm address */
89 ACPI_SMB_ALARM_DATA = 0x26, /* 2 bytes alarm data */
94 static inline int smb_hc_read(struct acpi_smb_hc *hc, u8 address, u8 *data)
96 return ec_read(hc->offset + address, data);
99 static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data)
101 return ec_write(hc->offset + address, data);
104 static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout)
106 if (wait_event_timeout(hc->wait, hc->done, msecs_to_jiffies(timeout)))
111 static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
112 u8 address, u8 command, u8 *data, u8 length)
114 int ret = -EFAULT, i;
118 printk(KERN_ERR PREFIX "host controller is not configured\n");
122 mutex_lock(&hc->lock);
126 if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
132 smb_hc_write(hc, ACPI_SMB_COMMAND, command);
133 if (!(protocol & 0x01)) {
134 smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length);
135 for (i = 0; i < length; ++i)
136 smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]);
138 smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
139 smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
141 * Wait for completion. Save the status code, data size,
142 * and data into the return package (if required by the protocol).
144 ret = wait_transaction_complete(hc, 1000);
145 if (ret || !(protocol & 0x01))
148 case SMBUS_RECEIVE_BYTE:
149 case SMBUS_READ_BYTE:
152 case SMBUS_READ_WORD:
155 case SMBUS_READ_BLOCK:
156 if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) {
163 for (i = 0; i < sz; ++i)
164 smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]);
166 mutex_unlock(&hc->lock);
170 int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
171 u8 command, u8 *data)
173 return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
176 EXPORT_SYMBOL_GPL(acpi_smbus_read);
178 int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
179 u8 command, u8 *data, u8 length)
181 return acpi_smbus_transaction(hc, protocol, address, command, data, length);
184 EXPORT_SYMBOL_GPL(acpi_smbus_write);
186 int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
187 smbus_alarm_callback callback, void *context)
189 mutex_lock(&hc->lock);
190 hc->callback = callback;
191 hc->context = context;
192 mutex_unlock(&hc->lock);
196 EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);
198 int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
200 mutex_lock(&hc->lock);
203 mutex_unlock(&hc->lock);
207 EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);
209 static inline void acpi_smbus_callback(void *context)
211 struct acpi_smb_hc *hc = context;
213 hc->callback(hc->context);
216 static int smbus_alarm(void *context)
218 struct acpi_smb_hc *hc = context;
219 union acpi_smb_status status;
221 if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw))
223 /* Check if it is only a completion notify */
224 if (status.fields.done && status.fields.status == SMBUS_OK) {
228 if (!status.fields.alarm)
230 mutex_lock(&hc->lock);
231 smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address);
232 status.fields.alarm = 0;
233 smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
234 /* We are only interested in events coming from known devices */
235 switch (address >> 1) {
236 case ACPI_SBS_CHARGER:
237 case ACPI_SBS_MANAGER:
238 case ACPI_SBS_BATTERY:
239 acpi_os_execute(OSL_NOTIFY_HANDLER,
240 acpi_smbus_callback, hc);
243 mutex_unlock(&hc->lock);
247 typedef int (*acpi_ec_query_func) (void *data);
249 extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
250 acpi_handle handle, acpi_ec_query_func func,
253 static int macbook_dmi_match(const struct dmi_system_id *d)
255 pr_debug("Detected MacBook, enabling workaround\n");
260 static struct dmi_system_id acpi_smbus_dmi_table[] = {
261 { macbook_dmi_match, "Apple MacBook", {
262 DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
263 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook") },
268 static int acpi_smbus_hc_add(struct acpi_device *device)
271 unsigned long long val;
272 struct acpi_smb_hc *hc;
274 dmi_check_system(acpi_smbus_dmi_table);
279 status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val);
280 if (ACPI_FAILURE(status)) {
281 printk(KERN_ERR PREFIX "error obtaining _EC.\n");
285 strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
286 strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
288 hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL);
291 mutex_init(&hc->lock);
292 init_waitqueue_head(&hc->wait);
294 hc->ec = acpi_driver_data(device->parent);
295 hc->offset = (val >> 8) & 0xff;
296 hc->query_bit = val & 0xff;
297 device->driver_data = hc;
299 acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc);
300 printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n",
301 hc->ec, hc->offset, hc->query_bit);
306 extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
308 static int acpi_smbus_hc_remove(struct acpi_device *device)
310 struct acpi_smb_hc *hc;
315 hc = acpi_driver_data(device);
316 acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
318 device->driver_data = NULL;
322 module_acpi_driver(acpi_smb_hc_driver);
324 MODULE_LICENSE("GPL");
325 MODULE_AUTHOR("Alexey Starikovskiy");
326 MODULE_DESCRIPTION("ACPI SMBus HC driver");