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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6/drivers/acpi/
1/*
2 * SMBus driver for ACPI Embedded Controller (v0.1)
3 *
4 * Copyright (c) 2007 Alexey Starikovskiy
5 *
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.
9 */
10
11#include <acpi/acpi_bus.h>
12#include <acpi/acpi_drivers.h>
13#include <linux/wait.h>
14#include <linux/slab.h>
15#include <linux/delay.h>
16#include <linux/interrupt.h>
17#include "sbshc.h"
18
19#define PREFIX "ACPI: "
20
21#define ACPI_SMB_HC_CLASS	"smbus_host_ctl"
22#define ACPI_SMB_HC_DEVICE_NAME	"ACPI SMBus HC"
23
24struct acpi_smb_hc {
25	struct acpi_ec *ec;
26	struct mutex lock;
27	wait_queue_head_t wait;
28	u8 offset;
29	u8 query_bit;
30	smbus_alarm_callback callback;
31	void *context;
32};
33
34static int acpi_smbus_hc_add(struct acpi_device *device);
35static int acpi_smbus_hc_remove(struct acpi_device *device, int type);
36
37static const struct acpi_device_id sbs_device_ids[] = {
38	{"ACPI0001", 0},
39	{"ACPI0005", 0},
40	{"", 0},
41};
42
43MODULE_DEVICE_TABLE(acpi, sbs_device_ids);
44
45static struct acpi_driver acpi_smb_hc_driver = {
46	.name = "smbus_hc",
47	.class = ACPI_SMB_HC_CLASS,
48	.ids = sbs_device_ids,
49	.ops = {
50		.add = acpi_smbus_hc_add,
51		.remove = acpi_smbus_hc_remove,
52		},
53};
54
55union acpi_smb_status {
56	u8 raw;
57	struct {
58		u8 status:5;
59		u8 reserved:1;
60		u8 alarm:1;
61		u8 done:1;
62	} fields;
63};
64
65enum acpi_smb_status_codes {
66	SMBUS_OK = 0,
67	SMBUS_UNKNOWN_FAILURE = 0x07,
68	SMBUS_DEVICE_ADDRESS_NACK = 0x10,
69	SMBUS_DEVICE_ERROR = 0x11,
70	SMBUS_DEVICE_COMMAND_ACCESS_DENIED = 0x12,
71	SMBUS_UNKNOWN_ERROR = 0x13,
72	SMBUS_DEVICE_ACCESS_DENIED = 0x17,
73	SMBUS_TIMEOUT = 0x18,
74	SMBUS_HOST_UNSUPPORTED_PROTOCOL = 0x19,
75	SMBUS_BUSY = 0x1a,
76	SMBUS_PEC_ERROR = 0x1f,
77};
78
79enum acpi_smb_offset {
80	ACPI_SMB_PROTOCOL = 0,	/* protocol, PEC */
81	ACPI_SMB_STATUS = 1,	/* status */
82	ACPI_SMB_ADDRESS = 2,	/* address */
83	ACPI_SMB_COMMAND = 3,	/* command */
84	ACPI_SMB_DATA = 4,	/* 32 data registers */
85	ACPI_SMB_BLOCK_COUNT = 0x24,	/* number of data bytes */
86	ACPI_SMB_ALARM_ADDRESS = 0x25,	/* alarm address */
87	ACPI_SMB_ALARM_DATA = 0x26,	/* 2 bytes alarm data */
88};
89
90static inline int smb_hc_read(struct acpi_smb_hc *hc, u8 address, u8 *data)
91{
92	return ec_read(hc->offset + address, data);
93}
94
95static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data)
96{
97	return ec_write(hc->offset + address, data);
98}
99
100static inline int smb_check_done(struct acpi_smb_hc *hc)
101{
102	union acpi_smb_status status = {.raw = 0};
103	smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw);
104	return status.fields.done && (status.fields.status == SMBUS_OK);
105}
106
107static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout)
108{
109	if (wait_event_timeout(hc->wait, smb_check_done(hc),
110			       msecs_to_jiffies(timeout)))
111		return 0;
112	/*
113	 * After the timeout happens, OS will try to check the status of SMbus.
114	 * If the status is what OS expected, it will be regarded as the bogus
115	 * timeout.
116	 */
117	if (smb_check_done(hc))
118		return 0;
119	else
120		return -ETIME;
121}
122
123static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
124				  u8 address, u8 command, u8 *data, u8 length)
125{
126	int ret = -EFAULT, i;
127	u8 temp, sz = 0;
128
129	if (!hc) {
130		printk(KERN_ERR PREFIX "host controller is not configured\n");
131		return ret;
132	}
133
134	mutex_lock(&hc->lock);
135	if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
136		goto end;
137	if (temp) {
138		ret = -EBUSY;
139		goto end;
140	}
141	smb_hc_write(hc, ACPI_SMB_COMMAND, command);
142	if (!(protocol & 0x01)) {
143		smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length);
144		for (i = 0; i < length; ++i)
145			smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]);
146	}
147	smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
148	smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
149	/*
150	 * Wait for completion. Save the status code, data size,
151	 * and data into the return package (if required by the protocol).
152	 */
153	ret = wait_transaction_complete(hc, 1000);
154	if (ret || !(protocol & 0x01))
155		goto end;
156	switch (protocol) {
157	case SMBUS_RECEIVE_BYTE:
158	case SMBUS_READ_BYTE:
159		sz = 1;
160		break;
161	case SMBUS_READ_WORD:
162		sz = 2;
163		break;
164	case SMBUS_READ_BLOCK:
165		if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) {
166			ret = -EFAULT;
167			goto end;
168		}
169		sz &= 0x1f;
170		break;
171	}
172	for (i = 0; i < sz; ++i)
173		smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]);
174      end:
175	mutex_unlock(&hc->lock);
176	return ret;
177}
178
179int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
180		    u8 command, u8 *data)
181{
182	return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
183}
184
185EXPORT_SYMBOL_GPL(acpi_smbus_read);
186
187int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
188		     u8 command, u8 *data, u8 length)
189{
190	return acpi_smbus_transaction(hc, protocol, address, command, data, length);
191}
192
193EXPORT_SYMBOL_GPL(acpi_smbus_write);
194
195int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
196			         smbus_alarm_callback callback, void *context)
197{
198	mutex_lock(&hc->lock);
199	hc->callback = callback;
200	hc->context = context;
201	mutex_unlock(&hc->lock);
202	return 0;
203}
204
205EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);
206
207int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
208{
209	mutex_lock(&hc->lock);
210	hc->callback = NULL;
211	hc->context = NULL;
212	mutex_unlock(&hc->lock);
213	return 0;
214}
215
216EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);
217
218static inline void acpi_smbus_callback(void *context)
219{
220	struct acpi_smb_hc *hc = context;
221	if (hc->callback)
222		hc->callback(hc->context);
223}
224
225static int smbus_alarm(void *context)
226{
227	struct acpi_smb_hc *hc = context;
228	union acpi_smb_status status;
229	u8 address;
230	if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw))
231		return 0;
232	/* Check if it is only a completion notify */
233	if (status.fields.done)
234		wake_up(&hc->wait);
235	if (!status.fields.alarm)
236		return 0;
237	mutex_lock(&hc->lock);
238	smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address);
239	status.fields.alarm = 0;
240	smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
241	/* We are only interested in events coming from known devices */
242	switch (address >> 1) {
243		case ACPI_SBS_CHARGER:
244		case ACPI_SBS_MANAGER:
245		case ACPI_SBS_BATTERY:
246			acpi_os_execute(OSL_NOTIFY_HANDLER,
247					acpi_smbus_callback, hc);
248		default:;
249	}
250	mutex_unlock(&hc->lock);
251	return 0;
252}
253
254typedef int (*acpi_ec_query_func) (void *data);
255
256extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
257			      acpi_handle handle, acpi_ec_query_func func,
258			      void *data);
259
260static int acpi_smbus_hc_add(struct acpi_device *device)
261{
262	int status;
263	unsigned long long val;
264	struct acpi_smb_hc *hc;
265
266	if (!device)
267		return -EINVAL;
268
269	status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val);
270	if (ACPI_FAILURE(status)) {
271		printk(KERN_ERR PREFIX "error obtaining _EC.\n");
272		return -EIO;
273	}
274
275	strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
276	strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
277
278	hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL);
279	if (!hc)
280		return -ENOMEM;
281	mutex_init(&hc->lock);
282	init_waitqueue_head(&hc->wait);
283
284	hc->ec = acpi_driver_data(device->parent);
285	hc->offset = (val >> 8) & 0xff;
286	hc->query_bit = val & 0xff;
287	device->driver_data = hc;
288
289	acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc);
290	printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n",
291		hc->ec, hc->offset, hc->query_bit);
292
293	return 0;
294}
295
296extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
297
298static int acpi_smbus_hc_remove(struct acpi_device *device, int type)
299{
300	struct acpi_smb_hc *hc;
301
302	if (!device)
303		return -EINVAL;
304
305	hc = acpi_driver_data(device);
306	acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
307	kfree(hc);
308	device->driver_data = NULL;
309	return 0;
310}
311
312static int __init acpi_smb_hc_init(void)
313{
314	int result;
315
316	result = acpi_bus_register_driver(&acpi_smb_hc_driver);
317	if (result < 0)
318		return -ENODEV;
319	return 0;
320}
321
322static void __exit acpi_smb_hc_exit(void)
323{
324	acpi_bus_unregister_driver(&acpi_smb_hc_driver);
325}
326
327module_init(acpi_smb_hc_init);
328module_exit(acpi_smb_hc_exit);
329
330MODULE_LICENSE("GPL");
331MODULE_AUTHOR("Alexey Starikovskiy");
332MODULE_DESCRIPTION("ACPI SMBus HC driver");
333