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;
35 static int acpi_smbus_hc_add(struct acpi_device *device);
36 static int acpi_smbus_hc_remove(struct acpi_device *device);
38 static const struct acpi_device_id sbs_device_ids[] = {
44 MODULE_DEVICE_TABLE(acpi, sbs_device_ids);
46 static struct acpi_driver acpi_smb_hc_driver = {
48 .class = ACPI_SMB_HC_CLASS,
49 .ids = sbs_device_ids,
51 .add = acpi_smbus_hc_add,
52 .remove = acpi_smbus_hc_remove,
56 union acpi_smb_status {
66 enum acpi_smb_status_codes {
68 SMBUS_UNKNOWN_FAILURE = 0x07,
69 SMBUS_DEVICE_ADDRESS_NACK = 0x10,
70 SMBUS_DEVICE_ERROR = 0x11,
71 SMBUS_DEVICE_COMMAND_ACCESS_DENIED = 0x12,
72 SMBUS_UNKNOWN_ERROR = 0x13,
73 SMBUS_DEVICE_ACCESS_DENIED = 0x17,
75 SMBUS_HOST_UNSUPPORTED_PROTOCOL = 0x19,
77 SMBUS_PEC_ERROR = 0x1f,
80 enum acpi_smb_offset {
81 ACPI_SMB_PROTOCOL = 0, /* protocol, PEC */
82 ACPI_SMB_STATUS = 1, /* status */
83 ACPI_SMB_ADDRESS = 2, /* address */
84 ACPI_SMB_COMMAND = 3, /* command */
85 ACPI_SMB_DATA = 4, /* 32 data registers */
86 ACPI_SMB_BLOCK_COUNT = 0x24, /* number of data bytes */
87 ACPI_SMB_ALARM_ADDRESS = 0x25, /* alarm address */
88 ACPI_SMB_ALARM_DATA = 0x26, /* 2 bytes alarm data */
93 static inline int smb_hc_read(struct acpi_smb_hc *hc, u8 address, u8 *data)
95 return ec_read(hc->offset + address, data);
98 static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data)
100 return ec_write(hc->offset + address, data);
103 static inline int smb_check_done(struct acpi_smb_hc *hc)
105 union acpi_smb_status status = {.raw = 0};
106 smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw);
107 return status.fields.done && (status.fields.status == SMBUS_OK);
110 static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout)
112 if (wait_event_timeout(hc->wait, smb_check_done(hc),
113 msecs_to_jiffies(timeout)))
116 * After the timeout happens, OS will try to check the status of SMbus.
117 * If the status is what OS expected, it will be regarded as the bogus
120 if (smb_check_done(hc))
126 static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
127 u8 address, u8 command, u8 *data, u8 length)
129 int ret = -EFAULT, i;
133 printk(KERN_ERR PREFIX "host controller is not configured\n");
137 mutex_lock(&hc->lock);
140 if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
146 smb_hc_write(hc, ACPI_SMB_COMMAND, command);
147 if (!(protocol & 0x01)) {
148 smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length);
149 for (i = 0; i < length; ++i)
150 smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]);
152 smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
153 smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
155 * Wait for completion. Save the status code, data size,
156 * and data into the return package (if required by the protocol).
158 ret = wait_transaction_complete(hc, 1000);
159 if (ret || !(protocol & 0x01))
162 case SMBUS_RECEIVE_BYTE:
163 case SMBUS_READ_BYTE:
166 case SMBUS_READ_WORD:
169 case SMBUS_READ_BLOCK:
170 if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) {
177 for (i = 0; i < sz; ++i)
178 smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]);
180 mutex_unlock(&hc->lock);
184 int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
185 u8 command, u8 *data)
187 return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
190 EXPORT_SYMBOL_GPL(acpi_smbus_read);
192 int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
193 u8 command, u8 *data, u8 length)
195 return acpi_smbus_transaction(hc, protocol, address, command, data, length);
198 EXPORT_SYMBOL_GPL(acpi_smbus_write);
200 int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
201 smbus_alarm_callback callback, void *context)
203 mutex_lock(&hc->lock);
204 hc->callback = callback;
205 hc->context = context;
206 mutex_unlock(&hc->lock);
210 EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);
212 int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
214 mutex_lock(&hc->lock);
217 mutex_unlock(&hc->lock);
221 EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);
223 static inline void acpi_smbus_callback(void *context)
225 struct acpi_smb_hc *hc = context;
227 hc->callback(hc->context);
230 static int smbus_alarm(void *context)
232 struct acpi_smb_hc *hc = context;
233 union acpi_smb_status status;
235 if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw))
237 /* Check if it is only a completion notify */
238 if (status.fields.done)
240 if (!status.fields.alarm)
242 mutex_lock(&hc->lock);
243 smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address);
244 status.fields.alarm = 0;
245 smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
246 /* We are only interested in events coming from known devices */
247 switch (address >> 1) {
248 case ACPI_SBS_CHARGER:
249 case ACPI_SBS_MANAGER:
250 case ACPI_SBS_BATTERY:
251 acpi_os_execute(OSL_NOTIFY_HANDLER,
252 acpi_smbus_callback, hc);
255 mutex_unlock(&hc->lock);
259 typedef int (*acpi_ec_query_func) (void *data);
261 extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
262 acpi_handle handle, acpi_ec_query_func func,
265 static int macbook_dmi_match(const struct dmi_system_id *d)
267 pr_debug("Detected MacBook, enabling workaround\n");
272 static struct dmi_system_id acpi_smbus_dmi_table[] = {
273 { macbook_dmi_match, "Apple MacBook", {
274 DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
275 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook") },
280 static int acpi_smbus_hc_add(struct acpi_device *device)
283 unsigned long long val;
284 struct acpi_smb_hc *hc;
286 dmi_check_system(acpi_smbus_dmi_table);
291 status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val);
292 if (ACPI_FAILURE(status)) {
293 printk(KERN_ERR PREFIX "error obtaining _EC.\n");
297 strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
298 strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
300 hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL);
303 mutex_init(&hc->lock);
304 init_waitqueue_head(&hc->wait);
306 hc->ec = acpi_driver_data(device->parent);
307 hc->offset = (val >> 8) & 0xff;
308 hc->query_bit = val & 0xff;
309 device->driver_data = hc;
311 acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc);
312 printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n",
313 hc->ec, hc->offset, hc->query_bit);
318 extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
320 static int acpi_smbus_hc_remove(struct acpi_device *device)
322 struct acpi_smb_hc *hc;
327 hc = acpi_driver_data(device);
328 acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
330 device->driver_data = NULL;
334 module_acpi_driver(acpi_smb_hc_driver);
336 MODULE_LICENSE("GPL");
337 MODULE_AUTHOR("Alexey Starikovskiy");
338 MODULE_DESCRIPTION("ACPI SMBus HC driver");