c1634c9716459b2ae302985c41d592575d9e85dc
[mirror_edk2.git] / MdeModulePkg / Bus / I2c / I2cDxe / I2cBus.c
1 /** @file
2 This file implements I2C IO Protocol which enables the user to manipulate a single
3 I2C device independent of the host controller and I2C design.
4
5 Copyright (c) 2013 - 2014, Intel Corporation. All rights reserved.<BR>
6 This program and the accompanying materials
7 are licensed and made available under the terms and conditions of the BSD License
8 which accompanies this distribution. The full text of the license may be found at
9 http://opensource.org/licenses/bsd-license.php
10
11 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
12 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
13
14 **/
15
16 #include "I2cDxe.h"
17
18 //
19 // EFI_DRIVER_BINDING_PROTOCOL instance
20 //
21 EFI_DRIVER_BINDING_PROTOCOL gI2cBusDriverBinding = {
22 I2cBusDriverSupported,
23 I2cBusDriverStart,
24 I2cBusDriverStop,
25 0x10,
26 NULL,
27 NULL
28 };
29
30 //
31 // Template for I2C Bus Child Device.
32 //
33 I2C_DEVICE_CONTEXT gI2cDeviceContextTemplate = {
34 I2C_DEVICE_SIGNATURE,
35 NULL,
36 { // I2cIo Protocol
37 I2cBusQueueRequest, // QueueRequest
38 NULL, // DeviceGuid
39 0, // DeviceIndex
40 0, // HardwareRevision
41 NULL // I2cControllerCapabilities
42 },
43 NULL, // DevicePath
44 NULL, // I2cDevice
45 NULL, // I2cBusContext
46 };
47
48 //
49 // Template for controller device path node.
50 //
51 CONTROLLER_DEVICE_PATH gControllerDevicePathTemplate = {
52 {
53 HARDWARE_DEVICE_PATH,
54 HW_CONTROLLER_DP,
55 {
56 (UINT8) (sizeof (CONTROLLER_DEVICE_PATH)),
57 (UINT8) ((sizeof (CONTROLLER_DEVICE_PATH)) >> 8)
58 }
59 },
60 0
61 };
62
63 //
64 // Template for vendor device path node.
65 //
66 VENDOR_DEVICE_PATH gVendorDevicePathTemplate = {
67 {
68 HARDWARE_DEVICE_PATH,
69 HW_VENDOR_DP,
70 {
71 (UINT8) (sizeof (VENDOR_DEVICE_PATH)),
72 (UINT8) ((sizeof (VENDOR_DEVICE_PATH)) >> 8)
73 }
74 },
75 { 0x0, 0x0, 0x0, { 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0 }}
76 };
77
78 //
79 // Driver name table
80 //
81 GLOBAL_REMOVE_IF_UNREFERENCED EFI_UNICODE_STRING_TABLE mI2cBusDriverNameTable[] = {
82 { "eng;en", (CHAR16 *) L"I2C Bus Driver" },
83 { NULL , NULL }
84 };
85
86 //
87 // EFI Component Name Protocol
88 //
89 GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME_PROTOCOL gI2cBusComponentName = {
90 (EFI_COMPONENT_NAME_GET_DRIVER_NAME) I2cBusComponentNameGetDriverName,
91 (EFI_COMPONENT_NAME_GET_CONTROLLER_NAME) I2cBusComponentNameGetControllerName,
92 "eng"
93 };
94
95 //
96 // EFI Component Name 2 Protocol
97 //
98 GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME2_PROTOCOL gI2cBusComponentName2 = {
99 I2cBusComponentNameGetDriverName,
100 I2cBusComponentNameGetControllerName,
101 "en"
102 };
103
104 /**
105 Retrieves a Unicode string that is the user readable name of the driver.
106
107 This function retrieves the user readable name of a driver in the form of a
108 Unicode string. If the driver specified by This has a user readable name in
109 the language specified by Language, then a pointer to the driver name is
110 returned in DriverName, and EFI_SUCCESS is returned. If the driver specified
111 by This does not support the language specified by Language,
112 then EFI_UNSUPPORTED is returned.
113
114 @param This[in] A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or
115 EFI_COMPONENT_NAME_PROTOCOL instance.
116
117 @param Language[in] A pointer to a Null-terminated ASCII string
118 array indicating the language. This is the
119 language of the driver name that the caller is
120 requesting, and it must match one of the
121 languages specified in SupportedLanguages. The
122 number of languages supported by a driver is up
123 to the driver writer. Language is specified
124 in RFC 4646 or ISO 639-2 language code format.
125
126 @param DriverName[out] A pointer to the Unicode string to return.
127 This Unicode string is the name of the
128 driver specified by This in the language
129 specified by Language.
130
131 @retval EFI_SUCCESS The Unicode string for the Driver specified by
132 This and the language specified by Language was
133 returned in DriverName.
134
135 @retval EFI_INVALID_PARAMETER Language is NULL.
136
137 @retval EFI_INVALID_PARAMETER DriverName is NULL.
138
139 @retval EFI_UNSUPPORTED The driver specified by This does not support
140 the language specified by Language.
141
142 **/
143 EFI_STATUS
144 EFIAPI
145 I2cBusComponentNameGetDriverName (
146 IN EFI_COMPONENT_NAME2_PROTOCOL *This,
147 IN CHAR8 *Language,
148 OUT CHAR16 **DriverName
149 )
150 {
151 return LookupUnicodeString2 (
152 Language,
153 This->SupportedLanguages,
154 mI2cBusDriverNameTable,
155 DriverName,
156 (BOOLEAN)(This != &gI2cBusComponentName2)
157 );
158 }
159
160 /**
161 Retrieves a Unicode string that is the user readable name of the controller
162 that is being managed by a driver.
163
164 This function retrieves the user readable name of the controller specified by
165 ControllerHandle and ChildHandle in the form of a Unicode string. If the
166 driver specified by This has a user readable name in the language specified by
167 Language, then a pointer to the controller name is returned in ControllerName,
168 and EFI_SUCCESS is returned. If the driver specified by This is not currently
169 managing the controller specified by ControllerHandle and ChildHandle,
170 then EFI_UNSUPPORTED is returned. If the driver specified by This does not
171 support the language specified by Language, then EFI_UNSUPPORTED is returned.
172
173 @param This[in] A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or
174 EFI_COMPONENT_NAME_PROTOCOL instance.
175
176 @param ControllerHandle[in] The handle of a controller that the driver
177 specified by This is managing. This handle
178 specifies the controller whose name is to be
179 returned.
180
181 @param ChildHandle[in] The handle of the child controller to retrieve
182 the name of. This is an optional parameter that
183 may be NULL. It will be NULL for device
184 drivers. It will also be NULL for a bus drivers
185 that wish to retrieve the name of the bus
186 controller. It will not be NULL for a bus
187 driver that wishes to retrieve the name of a
188 child controller.
189
190 @param Language[in] A pointer to a Null-terminated ASCII string
191 array indicating the language. This is the
192 language of the driver name that the caller is
193 requesting, and it must match one of the
194 languages specified in SupportedLanguages. The
195 number of languages supported by a driver is up
196 to the driver writer. Language is specified in
197 RFC 4646 or ISO 639-2 language code format.
198
199 @param ControllerName[out] A pointer to the Unicode string to return.
200 This Unicode string is the name of the
201 controller specified by ControllerHandle and
202 ChildHandle in the language specified by
203 Language from the point of view of the driver
204 specified by This.
205
206 @retval EFI_SUCCESS The Unicode string for the user readable name in
207 the language specified by Language for the
208 driver specified by This was returned in
209 DriverName.
210
211 @retval EFI_INVALID_PARAMETER ControllerHandle is NULL.
212
213 @retval EFI_INVALID_PARAMETER ChildHandle is not NULL and it is not a valid
214 EFI_HANDLE.
215
216 @retval EFI_INVALID_PARAMETER Language is NULL.
217
218 @retval EFI_INVALID_PARAMETER ControllerName is NULL.
219
220 @retval EFI_UNSUPPORTED The driver specified by This is not currently
221 managing the controller specified by
222 ControllerHandle and ChildHandle.
223
224 @retval EFI_UNSUPPORTED The driver specified by This does not support
225 the language specified by Language.
226
227 **/
228 EFI_STATUS
229 EFIAPI
230 I2cBusComponentNameGetControllerName (
231 IN EFI_COMPONENT_NAME2_PROTOCOL *This,
232 IN EFI_HANDLE ControllerHandle,
233 IN EFI_HANDLE ChildHandle OPTIONAL,
234 IN CHAR8 *Language,
235 OUT CHAR16 **ControllerName
236 )
237 {
238 return EFI_UNSUPPORTED;
239 }
240
241 /**
242 Check if the child of I2C controller has been created.
243
244 @param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
245 @param[in] Controller I2C controller handle.
246 @param[in] RemainingDevicePath A pointer to the remaining portion of a device path.
247 @param[in] RemainingHasControllerNode Indicate if RemainingDevicePath contains CONTROLLER_DEVICE_PATH.
248 @param[in] RemainingControllerNumber Controller number in CONTROLLER_DEVICE_PATH.
249
250 @retval EFI_SUCCESS The child of I2C controller is not created.
251 @retval Others The child of I2C controller has been created or other errors happen.
252
253 **/
254 EFI_STATUS
255 CheckRemainingDevicePath (
256 IN EFI_DRIVER_BINDING_PROTOCOL *This,
257 IN EFI_HANDLE Controller,
258 IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath,
259 IN BOOLEAN RemainingHasControllerNode,
260 IN UINT32 RemainingControllerNumber
261 )
262 {
263 EFI_STATUS Status;
264 EFI_DEVICE_PATH_PROTOCOL *SystemDevicePath;
265 EFI_OPEN_PROTOCOL_INFORMATION_ENTRY *OpenInfoBuffer;
266 UINTN EntryCount;
267 UINTN Index;
268 BOOLEAN SystemHasControllerNode;
269 UINT32 SystemControllerNumber;
270
271 SystemHasControllerNode = FALSE;
272 SystemControllerNumber = 0;
273
274 Status = gBS->OpenProtocolInformation (
275 Controller,
276 &gEfiI2cHostProtocolGuid,
277 &OpenInfoBuffer,
278 &EntryCount
279 );
280 if (EFI_ERROR (Status)) {
281 return Status;
282 }
283
284 for (Index = 0; Index < EntryCount; Index++) {
285 if ((OpenInfoBuffer[Index].Attributes & EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) != 0) {
286 Status = gBS->OpenProtocol (
287 OpenInfoBuffer[Index].ControllerHandle,
288 &gEfiDevicePathProtocolGuid,
289 (VOID **) &SystemDevicePath,
290 This->DriverBindingHandle,
291 Controller,
292 EFI_OPEN_PROTOCOL_GET_PROTOCOL
293 );
294 if (!EFI_ERROR (Status)) {
295 //
296 // Find vendor device path node and compare
297 //
298 while (!IsDevicePathEnd (SystemDevicePath)) {
299 if ((DevicePathType (SystemDevicePath) == HARDWARE_DEVICE_PATH) &&
300 (DevicePathSubType (SystemDevicePath) == HW_VENDOR_DP)) {
301 //
302 // Check if vendor device path is same between system device path and remaining device path
303 //
304 if (CompareMem (SystemDevicePath, RemainingDevicePath, sizeof (VENDOR_DEVICE_PATH)) == 0) {
305 //
306 // Get controller node appended after vendor node
307 //
308 SystemDevicePath = NextDevicePathNode (SystemDevicePath);
309 if ((DevicePathType (SystemDevicePath) == HARDWARE_DEVICE_PATH) &&
310 (DevicePathSubType (SystemDevicePath) == HW_CONTROLLER_DP)) {
311 SystemHasControllerNode = TRUE;
312 SystemControllerNumber = ((CONTROLLER_DEVICE_PATH *) SystemDevicePath)->ControllerNumber;
313 } else {
314 SystemHasControllerNode = FALSE;
315 SystemControllerNumber = 0;
316 }
317 if (((SystemHasControllerNode) && (!RemainingHasControllerNode) && (SystemControllerNumber == 0)) ||
318 ((!SystemHasControllerNode) && (RemainingHasControllerNode) && (RemainingControllerNumber == 0)) ||
319 ((SystemHasControllerNode) && (RemainingHasControllerNode) && (SystemControllerNumber == RemainingControllerNumber)) ||
320 ((!SystemHasControllerNode) && (!RemainingHasControllerNode))) {
321 DEBUG ((EFI_D_ERROR, "This I2C device has been already started.\n"));
322 Status = EFI_UNSUPPORTED;
323 break;
324 }
325 }
326 }
327 SystemDevicePath = NextDevicePathNode (SystemDevicePath);
328 }
329 if (EFI_ERROR (Status)) {
330 break;
331 }
332 }
333 }
334 }
335 FreePool (OpenInfoBuffer);
336 return Status;
337 }
338
339 /**
340 Tests to see if this driver supports a given controller. If a child device is provided,
341 it further tests to see if this driver supports creating a handle for the specified child device.
342
343 This function checks to see if the driver specified by This supports the device specified by
344 ControllerHandle. Drivers will typically use the device path attached to
345 ControllerHandle and/or the services from the bus I/O abstraction attached to
346 ControllerHandle to determine if the driver supports ControllerHandle. This function
347 may be called many times during platform initialization. In order to reduce boot times, the tests
348 performed by this function must be very small, and take as little time as possible to execute. This
349 function must not change the state of any hardware devices, and this function must be aware that the
350 device specified by ControllerHandle may already be managed by the same driver or a
351 different driver. This function must match its calls to AllocatePages() with FreePages(),
352 AllocatePool() with FreePool(), and OpenProtocol() with CloseProtocol().
353 Since ControllerHandle may have been previously started by the same driver, if a protocol is
354 already in the opened state, then it must not be closed with CloseProtocol(). This is required
355 to guarantee the state of ControllerHandle is not modified by this function.
356
357 @param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
358 @param[in] ControllerHandle The handle of the controller to test. This handle
359 must support a protocol interface that supplies
360 an I/O abstraction to the driver.
361 @param[in] RemainingDevicePath A pointer to the remaining portion of a device path. This
362 parameter is ignored by device drivers, and is optional for bus
363 drivers. For bus drivers, if this parameter is not NULL, then
364 the bus driver must determine if the bus controller specified
365 by ControllerHandle and the child controller specified
366 by RemainingDevicePath are both supported by this
367 bus driver.
368
369 @retval EFI_SUCCESS The device specified by ControllerHandle and
370 RemainingDevicePath is supported by the driver specified by This.
371 @retval EFI_ALREADY_STARTED The device specified by ControllerHandle and
372 RemainingDevicePath is already being managed by the driver
373 specified by This.
374 @retval EFI_ACCESS_DENIED The device specified by ControllerHandle and
375 RemainingDevicePath is already being managed by a different
376 driver or an application that requires exclusive access.
377 Currently not implemented.
378 @retval EFI_UNSUPPORTED The device specified by ControllerHandle and
379 RemainingDevicePath is not supported by the driver specified by This.
380 **/
381 EFI_STATUS
382 EFIAPI
383 I2cBusDriverSupported (
384 IN EFI_DRIVER_BINDING_PROTOCOL *This,
385 IN EFI_HANDLE Controller,
386 IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
387 )
388 {
389 EFI_STATUS Status;
390 EFI_I2C_ENUMERATE_PROTOCOL *I2cEnumerate;
391 EFI_I2C_HOST_PROTOCOL *I2cHost;
392 EFI_DEVICE_PATH_PROTOCOL *ParentDevicePath;
393 EFI_DEVICE_PATH_PROTOCOL *DevPathNode;
394 BOOLEAN RemainingHasControllerNode;
395 UINT32 RemainingControllerNumber;
396
397 RemainingHasControllerNode = FALSE;
398 RemainingControllerNumber = 0;
399
400 //
401 // Determine if the I2c Enumerate Protocol is available
402 //
403 Status = gBS->OpenProtocol (
404 Controller,
405 &gEfiI2cEnumerateProtocolGuid,
406 (VOID **) &I2cEnumerate,
407 This->DriverBindingHandle,
408 Controller,
409 EFI_OPEN_PROTOCOL_BY_DRIVER
410 );
411 if ((EFI_ERROR (Status)) && (Status != EFI_ALREADY_STARTED)) {
412 return Status;
413 }
414
415 if (!EFI_ERROR (Status)) {
416 gBS->CloseProtocol (
417 Controller,
418 &gEfiI2cEnumerateProtocolGuid,
419 This->DriverBindingHandle,
420 Controller
421 );
422 }
423
424 Status = gBS->OpenProtocol (
425 Controller,
426 &gEfiDevicePathProtocolGuid,
427 (VOID **) &ParentDevicePath,
428 This->DriverBindingHandle,
429 Controller,
430 EFI_OPEN_PROTOCOL_BY_DRIVER
431 );
432
433 if ((EFI_ERROR (Status)) && (Status != EFI_ALREADY_STARTED)) {
434 return Status;
435 }
436
437 if (!EFI_ERROR (Status)) {
438 gBS->CloseProtocol (
439 Controller,
440 &gEfiDevicePathProtocolGuid,
441 This->DriverBindingHandle,
442 Controller
443 );
444 }
445
446 if ((RemainingDevicePath != NULL) && !IsDevicePathEnd (RemainingDevicePath)) {
447 //
448 // Check if the first node of RemainingDevicePath is a hardware vendor device path
449 //
450 if ((DevicePathType (RemainingDevicePath) != HARDWARE_DEVICE_PATH) ||
451 (DevicePathSubType (RemainingDevicePath) != HW_VENDOR_DP)) {
452 return EFI_UNSUPPORTED;
453 }
454 //
455 // Check if the second node of RemainingDevicePath is a controller node
456 //
457 DevPathNode = NextDevicePathNode (RemainingDevicePath);
458 if (!IsDevicePathEnd (DevPathNode)) {
459 if ((DevicePathType (DevPathNode) != HARDWARE_DEVICE_PATH) ||
460 (DevicePathSubType (DevPathNode) != HW_CONTROLLER_DP)) {
461 return EFI_UNSUPPORTED;
462 } else {
463 RemainingHasControllerNode = TRUE;
464 RemainingControllerNumber = ((CONTROLLER_DEVICE_PATH *) DevPathNode)->ControllerNumber;
465 }
466 }
467 }
468
469 //
470 // Determine if the I2C Host Protocol is available
471 //
472 Status = gBS->OpenProtocol (
473 Controller,
474 &gEfiI2cHostProtocolGuid,
475 (VOID **) &I2cHost,
476 This->DriverBindingHandle,
477 Controller,
478 EFI_OPEN_PROTOCOL_BY_DRIVER
479 );
480
481 if (!EFI_ERROR (Status)) {
482 gBS->CloseProtocol (
483 Controller,
484 &gEfiI2cHostProtocolGuid,
485 This->DriverBindingHandle,
486 Controller
487 );
488 }
489
490
491 if (Status == EFI_ALREADY_STARTED) {
492 if ((RemainingDevicePath == NULL) ||
493 ((RemainingDevicePath != NULL) && IsDevicePathEnd (RemainingDevicePath))) {
494 //
495 // If RemainingDevicePath is NULL or is the End of Device Path Node, return EFI_SUCCESS.
496 //
497 Status = EFI_SUCCESS;
498 } else {
499 //
500 // Test if the child with the RemainingDevicePath has already been created.
501 //
502 Status = CheckRemainingDevicePath (
503 This,
504 Controller,
505 RemainingDevicePath,
506 RemainingHasControllerNode,
507 RemainingControllerNumber
508 );
509 }
510 }
511
512 return Status;
513 }
514
515 /**
516 Starts a device controller or a bus controller.
517
518 The Start() function is designed to be invoked from the EFI boot service ConnectController().
519 As a result, much of the error checking on the parameters to Start() has been moved into this
520 common boot service. It is legal to call Start() from other locations,
521 but the following calling restrictions must be followed or the system behavior will not be deterministic.
522 1. ControllerHandle must be a valid EFI_HANDLE.
523 2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned
524 EFI_DEVICE_PATH_PROTOCOL.
525 3. Prior to calling Start(), the Supported() function for the driver specified by This must
526 have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.
527
528 @param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
529 @param[in] ControllerHandle The handle of the controller to start. This handle
530 must support a protocol interface that supplies
531 an I/O abstraction to the driver.
532 @param[in] RemainingDevicePath A pointer to the remaining portion of a device path. This
533 parameter is ignored by device drivers, and is optional for bus
534 drivers. For a bus driver, if this parameter is NULL, then handles
535 for all the children of Controller are created by this driver.
536 If this parameter is not NULL and the first Device Path Node is
537 not the End of Device Path Node, then only the handle for the
538 child device specified by the first Device Path Node of
539 RemainingDevicePath is created by this driver.
540 If the first Device Path Node of RemainingDevicePath is
541 the End of Device Path Node, no child handle is created by this
542 driver.
543
544 @retval EFI_SUCCESS The device was started.
545 @retval EFI_DEVICE_ERROR The device could not be started due to a device error.Currently not implemented.
546 @retval EFI_OUT_OF_RESOURCES The request could not be completed due to a lack of resources.
547 @retval Others The driver failded to start the device.
548
549 **/
550 EFI_STATUS
551 EFIAPI
552 I2cBusDriverStart (
553 IN EFI_DRIVER_BINDING_PROTOCOL *This,
554 IN EFI_HANDLE Controller,
555 IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
556 )
557 {
558 EFI_I2C_ENUMERATE_PROTOCOL *I2cEnumerate;
559 EFI_I2C_HOST_PROTOCOL *I2cHost;
560 I2C_BUS_CONTEXT *I2cBusContext;
561 EFI_STATUS Status;
562 EFI_DEVICE_PATH_PROTOCOL *ParentDevicePath;
563
564 I2cBusContext = NULL;
565 ParentDevicePath = NULL;
566 I2cEnumerate = NULL;
567 I2cHost = NULL;
568
569 //
570 // Determine if the I2C controller is available
571 //
572 Status = gBS->OpenProtocol (
573 Controller,
574 &gEfiI2cHostProtocolGuid,
575 (VOID**)&I2cHost,
576 This->DriverBindingHandle,
577 Controller,
578 EFI_OPEN_PROTOCOL_BY_DRIVER
579 );
580 if (EFI_ERROR (Status) && (Status != EFI_ALREADY_STARTED)) {
581 DEBUG ((EFI_D_ERROR, "I2cBus: open I2C host error, Status = %r\n", Status));
582 return Status;
583 }
584
585 if (Status == EFI_ALREADY_STARTED) {
586 Status = gBS->OpenProtocol (
587 Controller,
588 &gEfiCallerIdGuid,
589 (VOID **) &I2cBusContext,
590 This->DriverBindingHandle,
591 Controller,
592 EFI_OPEN_PROTOCOL_GET_PROTOCOL
593 );
594 if (EFI_ERROR (Status)) {
595 DEBUG ((EFI_D_ERROR, "I2cBus: open private protocol error, Status = %r.\n", Status));
596 return Status;
597 }
598 }
599
600 //
601 // Get the I2C bus enumeration API
602 //
603 Status = gBS->OpenProtocol (
604 Controller,
605 &gEfiI2cEnumerateProtocolGuid,
606 (VOID**)&I2cEnumerate,
607 This->DriverBindingHandle,
608 Controller,
609 EFI_OPEN_PROTOCOL_BY_DRIVER
610 );
611 if (EFI_ERROR (Status) && (Status != EFI_ALREADY_STARTED)) {
612 DEBUG ((EFI_D_ERROR, "I2cBus: open I2C enumerate error, Status = %r\n", Status));
613 goto Error;
614 }
615
616 Status = gBS->OpenProtocol (
617 Controller,
618 &gEfiDevicePathProtocolGuid,
619 (VOID **) &ParentDevicePath,
620 This->DriverBindingHandle,
621 Controller,
622 EFI_OPEN_PROTOCOL_BY_DRIVER
623 );
624 if (EFI_ERROR (Status) && (Status != EFI_ALREADY_STARTED)) {
625 DEBUG ((EFI_D_ERROR, "I2cBus: open device path error, Status = %r\n", Status));
626 goto Error;
627 }
628
629 if ((RemainingDevicePath != NULL) && IsDevicePathEnd (RemainingDevicePath)) {
630 //
631 // If RemainingDevicePath is the End of Device Path Node,
632 // don't create any child device and return EFI_SUCESS
633 //
634 return EFI_SUCCESS;
635 }
636
637 //
638 // Allocate the buffer for I2C_BUS_CONTEXT if it is not allocated before.
639 //
640 if (I2cBusContext == NULL) {
641 //
642 // Allocate the I2C context structure for the current I2C controller
643 //
644 I2cBusContext = AllocateZeroPool (sizeof (I2C_BUS_CONTEXT));
645 if (I2cBusContext == NULL) {
646 DEBUG ((EFI_D_ERROR, "I2cBus: there is no enough memory to allocate.\n"));
647 Status = EFI_OUT_OF_RESOURCES;
648 goto Error;
649 }
650
651 /*
652 +----------------+
653 .->| I2C_BUS_CONTEXT|<----- This file Protocol (gEfiCallerIdGuid) installed on I2C Controller handle
654 | +----------------+
655 |
656 | +----------------------------+
657 | | I2C_DEVICE_CONTEXT |
658 `--| |
659 | |
660 | I2C IO Protocol Structure | <----- I2C IO Protocol
661 | |
662 +----------------------------+
663
664 */
665 I2cBusContext->I2cHost = I2cHost;
666 I2cBusContext->I2cEnumerate = I2cEnumerate;
667 //
668 // Parent controller used to create children
669 //
670 I2cBusContext->Controller = Controller;
671 //
672 // Parent controller device path used to create children device path
673 //
674 I2cBusContext->ParentDevicePath = ParentDevicePath;
675
676 I2cBusContext->DriverBindingHandle = This->DriverBindingHandle;
677
678 Status = gBS->InstallMultipleProtocolInterfaces (
679 &Controller,
680 &gEfiCallerIdGuid,
681 I2cBusContext,
682 NULL
683 );
684 if (EFI_ERROR (Status)) {
685 DEBUG ((EFI_D_ERROR, "I2cBus: install private protocol error, Status = %r.\n", Status));
686 goto Error;
687 }
688 }
689
690 //
691 // Start the driver
692 //
693 Status = RegisterI2cDevice (I2cBusContext, Controller, RemainingDevicePath);
694
695 return Status;
696
697 Error:
698 if (EFI_ERROR (Status)) {
699 DEBUG ((EFI_D_ERROR, "I2cBus: Start() function failed, Status = %r\n", Status));
700 if (ParentDevicePath != NULL) {
701 gBS->CloseProtocol (
702 Controller,
703 &gEfiDevicePathProtocolGuid,
704 This->DriverBindingHandle,
705 Controller
706 );
707 }
708
709 if (I2cHost != NULL) {
710 gBS->CloseProtocol (
711 Controller,
712 &gEfiI2cHostProtocolGuid,
713 This->DriverBindingHandle,
714 Controller
715 );
716 }
717
718 if (I2cEnumerate != NULL) {
719 gBS->CloseProtocol (
720 Controller,
721 &gEfiI2cEnumerateProtocolGuid,
722 This->DriverBindingHandle,
723 Controller
724 );
725 }
726
727 if (I2cBusContext != NULL) {
728 Status = gBS->UninstallMultipleProtocolInterfaces (
729 &Controller,
730 gEfiCallerIdGuid,
731 I2cBusContext,
732 NULL
733 );
734 FreePool (I2cBusContext);
735 }
736 }
737
738 //
739 // Return the operation status.
740 //
741 return Status;
742 }
743
744
745 /**
746 Stops a device controller or a bus controller.
747
748 The Stop() function is designed to be invoked from the EFI boot service DisconnectController().
749 As a result, much of the error checking on the parameters to Stop() has been moved
750 into this common boot service. It is legal to call Stop() from other locations,
751 but the following calling restrictions must be followed or the system behavior will not be deterministic.
752 1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this
753 same driver's Start() function.
754 2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid
755 EFI_HANDLE. In addition, all of these handles must have been created in this driver's
756 Start() function, and the Start() function must have called OpenProtocol() on
757 ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.
758
759 @param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
760 @param[in] ControllerHandle A handle to the device being stopped. The handle must
761 support a bus specific I/O protocol for the driver
762 to use to stop the device.
763 @param[in] NumberOfChildren The number of child device handles in ChildHandleBuffer.
764 @param[in] ChildHandleBuffer An array of child handles to be freed. May be NULL
765 if NumberOfChildren is 0.
766
767 @retval EFI_SUCCESS The device was stopped.
768 @retval EFI_DEVICE_ERROR The device could not be stopped due to a device error.
769
770 **/
771 EFI_STATUS
772 EFIAPI
773 I2cBusDriverStop (
774 IN EFI_DRIVER_BINDING_PROTOCOL *This,
775 IN EFI_HANDLE Controller,
776 IN UINTN NumberOfChildren,
777 IN EFI_HANDLE *ChildHandleBuffer
778 )
779 {
780 I2C_BUS_CONTEXT *I2cBusContext;
781 EFI_STATUS Status;
782 BOOLEAN AllChildrenStopped;
783 UINTN Index;
784
785 if (NumberOfChildren == 0) {
786 gBS->CloseProtocol (
787 Controller,
788 &gEfiDevicePathProtocolGuid,
789 This->DriverBindingHandle,
790 Controller
791 );
792
793 gBS->CloseProtocol (
794 Controller,
795 &gEfiI2cHostProtocolGuid,
796 This->DriverBindingHandle,
797 Controller
798 );
799
800 gBS->CloseProtocol (
801 Controller,
802 &gEfiI2cEnumerateProtocolGuid,
803 This->DriverBindingHandle,
804 Controller
805 );
806
807 Status = gBS->OpenProtocol (
808 Controller,
809 &gEfiCallerIdGuid,
810 (VOID **) &I2cBusContext,
811 This->DriverBindingHandle,
812 Controller,
813 EFI_OPEN_PROTOCOL_GET_PROTOCOL
814 );
815 if (!EFI_ERROR (Status)) {
816 gBS->UninstallMultipleProtocolInterfaces (
817 Controller,
818 &gEfiCallerIdGuid,
819 I2cBusContext,
820 NULL
821 );
822 //
823 // No more child now, free bus context data.
824 //
825 FreePool (I2cBusContext);
826 }
827 return Status;
828 }
829
830 AllChildrenStopped = TRUE;
831
832 for (Index = 0; Index < NumberOfChildren; Index++) {
833
834 Status = UnRegisterI2cDevice (This, Controller, ChildHandleBuffer[Index]);
835 if (EFI_ERROR (Status)) {
836 AllChildrenStopped = FALSE;
837 }
838 }
839
840 if (!AllChildrenStopped) {
841 return EFI_DEVICE_ERROR;
842 }
843 return EFI_SUCCESS;
844 }
845
846 /**
847 Enumerate the I2C bus
848
849 This routine walks the platform specific data describing the
850 I2C bus to create the I2C devices where driver GUIDs were
851 specified.
852
853 @param[in] I2cBusContext Address of an I2C_BUS_CONTEXT structure
854 @param[in] Controller Handle to the controller
855 @param[in] RemainingDevicePath A pointer to the remaining portion of a device path.
856
857 @retval EFI_SUCCESS The bus is successfully configured
858
859 **/
860 EFI_STATUS
861 RegisterI2cDevice (
862 IN I2C_BUS_CONTEXT *I2cBusContext,
863 IN EFI_HANDLE Controller,
864 IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
865 )
866 {
867 I2C_DEVICE_CONTEXT *I2cDeviceContext;
868 EFI_STATUS Status;
869 CONST EFI_I2C_DEVICE *Device;
870 CONST EFI_I2C_DEVICE *TempDevice;
871 UINT32 RemainingPathDeviceIndex;
872 EFI_DEVICE_PATH_PROTOCOL *DevPathNode;
873 BOOLEAN BuildControllerNode;
874 UINTN Count;
875
876 Status = EFI_SUCCESS;
877 BuildControllerNode = TRUE;
878
879 //
880 // Default DeviceIndex
881 //
882 RemainingPathDeviceIndex = 0;
883
884 //
885 // Determine the controller number in Controller Node Device Path when RemainingDevicePath is not NULL.
886 //
887 if (RemainingDevicePath != NULL) {
888 //
889 // Check if there is a controller node appended after vendor node
890 //
891 DevPathNode = NextDevicePathNode (RemainingDevicePath);
892 if ((DevicePathType (DevPathNode) == HARDWARE_DEVICE_PATH) &&
893 (DevicePathSubType(DevPathNode) == HW_CONTROLLER_DP)) {
894 //
895 // RemainingDevicePath != NULL and RemainingDevicePath contains Controller Node,
896 // add Controller Node to Device Path on child handle.
897 //
898 RemainingPathDeviceIndex = ((CONTROLLER_DEVICE_PATH *) DevPathNode)->ControllerNumber;
899 } else {
900 //
901 // RemainingDevicePath != NULL and RemainingDevicePath does not contain Controller Node,
902 // do not add controller node to Device Path on child handle.
903 //
904 BuildControllerNode = FALSE;
905 }
906 }
907
908 //
909 // Walk the list of I2C devices on this bus
910 //
911 Device = NULL;
912 while (TRUE) {
913 //
914 // Get the next I2C device
915 //
916 Status = I2cBusContext->I2cEnumerate->Enumerate (I2cBusContext->I2cEnumerate, &Device);
917 if (EFI_ERROR (Status) || Device == NULL) {
918 if (RemainingDevicePath != NULL) {
919 Status = EFI_NOT_FOUND;
920 } else {
921 Status = EFI_SUCCESS;
922 }
923 break;
924 }
925
926 //
927 // Determine if the device info is valid
928 //
929 if ((Device->DeviceGuid == NULL) || (Device->SlaveAddressCount == 0) || (Device->SlaveAddressArray == NULL)) {
930 DEBUG ((EFI_D_ERROR, "Invalid EFI_I2C_DEVICE reported by I2c Enumerate protocol.\n"));
931 continue;
932 }
933
934 if (RemainingDevicePath == NULL) {
935 if (Device->DeviceIndex == 0) {
936 //
937 // Determine if the controller node is necessary when controller number is zero in I2C device
938 //
939 TempDevice = NULL;
940 Count = 0;
941 while (TRUE) {
942 //
943 // Get the next I2C device
944 //
945 Status = I2cBusContext->I2cEnumerate->Enumerate (I2cBusContext->I2cEnumerate, &TempDevice);
946 if (EFI_ERROR (Status) || TempDevice == NULL) {
947 Status = EFI_SUCCESS;
948 break;
949 }
950 if (CompareGuid (Device->DeviceGuid, TempDevice->DeviceGuid)) {
951 Count++;
952 }
953 }
954 if (Count == 1) {
955 //
956 // RemainingDevicePath == NULL and only DeviceIndex 0 is present on the I2C bus,
957 // do not add Controller Node to Device Path on child handle.
958 //
959 BuildControllerNode = FALSE;
960 }
961 }
962 } else {
963 //
964 // Find I2C device reported in Remaining Device Path
965 //
966 if ((!CompareGuid (&((VENDOR_DEVICE_PATH *)RemainingDevicePath)->Guid, Device->DeviceGuid)) ||
967 (RemainingPathDeviceIndex != Device->DeviceIndex)) {
968 continue;
969 }
970 }
971
972 //
973 // Build the device context for current I2C device.
974 //
975 I2cDeviceContext = NULL;
976 I2cDeviceContext = AllocateCopyPool (sizeof (I2C_DEVICE_CONTEXT), &gI2cDeviceContextTemplate);
977 ASSERT (I2cDeviceContext != NULL);
978 if (I2cDeviceContext == NULL) {
979 continue;
980 }
981
982 //
983 // Initialize the specific device context
984 //
985 I2cDeviceContext->I2cBusContext = I2cBusContext;
986 I2cDeviceContext->I2cDevice = Device;
987 I2cDeviceContext->I2cIo.DeviceGuid = Device->DeviceGuid;
988 I2cDeviceContext->I2cIo.DeviceIndex = Device->DeviceIndex;
989 I2cDeviceContext->I2cIo.HardwareRevision = Device->HardwareRevision;
990 I2cDeviceContext->I2cIo.I2cControllerCapabilities = I2cBusContext->I2cHost->I2cControllerCapabilities;
991
992 //
993 // Build the device path
994 //
995 Status = I2cBusDevicePathAppend (I2cDeviceContext, BuildControllerNode);
996 ASSERT_EFI_ERROR (Status);
997 if (EFI_ERROR (Status)) {
998 continue;
999 }
1000
1001 //
1002 // Install the protocol
1003 //
1004 Status = gBS->InstallMultipleProtocolInterfaces (
1005 &I2cDeviceContext->Handle,
1006 &gEfiI2cIoProtocolGuid,
1007 &I2cDeviceContext->I2cIo,
1008 &gEfiDevicePathProtocolGuid,
1009 I2cDeviceContext->DevicePath,
1010 NULL );
1011 if (EFI_ERROR (Status)) {
1012 //
1013 // Free resources for this I2C device
1014 //
1015 ReleaseI2cDeviceContext (I2cDeviceContext);
1016 continue;
1017 }
1018
1019 //
1020 // Create the child handle
1021 //
1022 Status = gBS->OpenProtocol (
1023 Controller,
1024 &gEfiI2cHostProtocolGuid,
1025 (VOID **) &I2cBusContext->I2cHost,
1026 I2cBusContext->DriverBindingHandle,
1027 I2cDeviceContext->Handle,
1028 EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER
1029 );
1030 if (EFI_ERROR (Status)) {
1031 Status = gBS->UninstallMultipleProtocolInterfaces (
1032 I2cDeviceContext->Handle,
1033 &gEfiDevicePathProtocolGuid,
1034 I2cDeviceContext->DevicePath,
1035 &gEfiI2cIoProtocolGuid,
1036 &I2cDeviceContext->I2cIo,
1037 NULL
1038 );
1039 //
1040 // Free resources for this I2C device
1041 //
1042 ReleaseI2cDeviceContext (I2cDeviceContext);
1043 continue;
1044 }
1045
1046 if (RemainingDevicePath != NULL) {
1047 //
1048 // Child has been created successfully
1049 //
1050 break;
1051 }
1052 }
1053
1054 return Status;
1055 }
1056
1057
1058 /**
1059 Queue an I2C transaction for execution on the I2C device.
1060
1061 This routine must be called at or below TPL_NOTIFY. For synchronous
1062 requests this routine must be called at or below TPL_CALLBACK.
1063
1064 This routine queues an I2C transaction to the I2C controller for
1065 execution on the I2C bus.
1066
1067 When Event is NULL, QueueRequest() operates synchronously and returns
1068 the I2C completion status as its return value.
1069
1070 When Event is not NULL, QueueRequest() synchronously returns EFI_SUCCESS
1071 indicating that the asynchronous I2C transaction was queued. The values
1072 above are returned in the buffer pointed to by I2cStatus upon the
1073 completion of the I2C transaction when I2cStatus is not NULL.
1074
1075 The upper layer driver writer provides the following to the platform
1076 vendor:
1077
1078 1. Vendor specific GUID for the I2C part
1079 2. Guidance on proper construction of the slave address array when the
1080 I2C device uses more than one slave address. The I2C bus protocol
1081 uses the SlaveAddressIndex to perform relative to physical address
1082 translation to access the blocks of hardware within the I2C device.
1083
1084 @param[in] This Pointer to an EFI_I2C_IO_PROTOCOL structure.
1085 @param[in] SlaveAddressIndex Index value into an array of slave addresses
1086 for the I2C device. The values in the array
1087 are specified by the board designer, with the
1088 third party I2C device driver writer providing
1089 the slave address order.
1090
1091 For devices that have a single slave address,
1092 this value must be zero. If the I2C device
1093 uses more than one slave address then the
1094 third party (upper level) I2C driver writer
1095 needs to specify the order of entries in the
1096 slave address array.
1097
1098 \ref ThirdPartyI2cDrivers "Third Party I2C
1099 Drivers" section in I2cMaster.h.
1100 @param[in] Event Event to signal for asynchronous transactions,
1101 NULL for synchronous transactions
1102 @param[in] RequestPacket Pointer to an EFI_I2C_REQUEST_PACKET structure
1103 describing the I2C transaction
1104 @param[out] I2cStatus Optional buffer to receive the I2C transaction
1105 completion status
1106
1107 @retval EFI_SUCCESS The asynchronous transaction was successfully
1108 queued when Event is not NULL.
1109 @retval EFI_SUCCESS The transaction completed successfully when
1110 Event is NULL.
1111 @retval EFI_ABORTED The request did not complete because the driver
1112 binding Stop() routine was called.
1113 @retval EFI_BAD_BUFFER_SIZE The RequestPacket->LengthInBytes value is too
1114 large.
1115 @retval EFI_DEVICE_ERROR There was an I2C error (NACK) during the
1116 transaction.
1117 @retval EFI_INVALID_PARAMETER RequestPacket is NULL
1118 @retval EFI_NO_MAPPING The EFI_I2C_HOST_PROTOCOL could not set the
1119 bus configuration required to access this I2C
1120 device.
1121 @retval EFI_NO_RESPONSE The I2C device is not responding to the slave
1122 address selected by SlaveAddressIndex.
1123 EFI_DEVICE_ERROR will be returned if the
1124 controller cannot distinguish when the NACK
1125 occurred.
1126 @retval EFI_OUT_OF_RESOURCES Insufficient memory for I2C transaction
1127 @retval EFI_UNSUPPORTED The controller does not support the requested
1128 transaction.
1129
1130 **/
1131 EFI_STATUS
1132 EFIAPI
1133 I2cBusQueueRequest (
1134 IN CONST EFI_I2C_IO_PROTOCOL *This,
1135 IN UINTN SlaveAddressIndex,
1136 IN EFI_EVENT Event OPTIONAL,
1137 IN EFI_I2C_REQUEST_PACKET *RequestPacket,
1138 OUT EFI_STATUS *I2cStatus OPTIONAL
1139 )
1140 {
1141 CONST EFI_I2C_DEVICE *I2cDevice;
1142 I2C_BUS_CONTEXT *I2cBusContext;
1143 CONST EFI_I2C_HOST_PROTOCOL *I2cHost;
1144 I2C_DEVICE_CONTEXT *I2cDeviceContext;
1145 EFI_STATUS Status;
1146
1147 if (RequestPacket == NULL) {
1148 return EFI_INVALID_PARAMETER;
1149 }
1150
1151 //
1152 // Validate the I2C slave index
1153 //
1154 I2cDeviceContext = I2C_DEVICE_CONTEXT_FROM_PROTOCOL (This);
1155 I2cDevice = I2cDeviceContext->I2cDevice;
1156 if ( SlaveAddressIndex >= I2cDevice->SlaveAddressCount ) {
1157 return EFI_INVALID_PARAMETER;
1158 }
1159
1160 //
1161 // Locate the I2c Host Protocol to queue request
1162 //
1163 I2cBusContext = I2cDeviceContext->I2cBusContext;
1164 I2cHost = I2cBusContext->I2cHost;
1165
1166 //
1167 // Start the I2C operation
1168 //
1169 Status = I2cHost->QueueRequest (
1170 I2cHost,
1171 I2cDevice->I2cBusConfiguration,
1172 I2cDevice->SlaveAddressArray [SlaveAddressIndex],
1173 Event,
1174 RequestPacket,
1175 I2cStatus
1176 );
1177
1178 return Status;
1179 }
1180
1181 /**
1182 Release all the resources allocated for the I2C device.
1183
1184 This function releases all the resources allocated for the I2C device.
1185
1186 @param I2cDeviceContext The I2C child device involved for the operation.
1187
1188 **/
1189 VOID
1190 ReleaseI2cDeviceContext (
1191 IN I2C_DEVICE_CONTEXT *I2cDeviceContext
1192 )
1193 {
1194 if (I2cDeviceContext == NULL) {
1195 return;
1196 }
1197
1198 if (I2cDeviceContext->DevicePath != NULL) {
1199 FreePool (I2cDeviceContext->DevicePath);
1200 }
1201
1202 FreePool (I2cDeviceContext);
1203 }
1204
1205 /**
1206 Unregister an I2C device.
1207
1208 This function removes the protocols installed on the controller handle and
1209 frees the resources allocated for the I2C device.
1210
1211 @param This The pointer to EFI_DRIVER_BINDING_PROTOCOL instance.
1212 @param Controller The controller handle of the I2C device.
1213 @param Handle The child handle.
1214
1215 @retval EFI_SUCCESS The I2C device is successfully unregistered.
1216 @return Others Some error occurs when unregistering the I2C device.
1217
1218 **/
1219 EFI_STATUS
1220 UnRegisterI2cDevice (
1221 IN EFI_DRIVER_BINDING_PROTOCOL *This,
1222 IN EFI_HANDLE Controller,
1223 IN EFI_HANDLE Handle
1224 )
1225 {
1226 EFI_STATUS Status;
1227 I2C_DEVICE_CONTEXT *I2cDeviceContext;
1228 EFI_I2C_IO_PROTOCOL *I2cIo;
1229 EFI_I2C_HOST_PROTOCOL *I2cHost;
1230
1231 I2cIo = NULL;
1232
1233 Status = gBS->OpenProtocol (
1234 Handle,
1235 &gEfiI2cIoProtocolGuid,
1236 (VOID **) &I2cIo,
1237 This->DriverBindingHandle,
1238 Controller,
1239 EFI_OPEN_PROTOCOL_GET_PROTOCOL
1240 );
1241 if (EFI_ERROR (Status)) {
1242 return Status;
1243 }
1244
1245 //
1246 // Get I2c device context data.
1247 //
1248 I2cDeviceContext = I2C_DEVICE_CONTEXT_FROM_PROTOCOL (I2cIo);
1249
1250 //
1251 // Close the child handle
1252 //
1253 gBS->CloseProtocol (
1254 Controller,
1255 &gEfiI2cHostProtocolGuid,
1256 This->DriverBindingHandle,
1257 Handle
1258 );
1259
1260 //
1261 // The I2C Bus driver installs the I2C Io and Device Path Protocol in the DriverBindingStart().
1262 // Here should uninstall them.
1263 //
1264 Status = gBS->UninstallMultipleProtocolInterfaces (
1265 Handle,
1266 &gEfiDevicePathProtocolGuid,
1267 I2cDeviceContext->DevicePath,
1268 &gEfiI2cIoProtocolGuid,
1269 &I2cDeviceContext->I2cIo,
1270 NULL
1271 );
1272
1273 if (EFI_ERROR (Status)) {
1274 //
1275 // Keep parent and child relationship
1276 //
1277 gBS->OpenProtocol (
1278 Controller,
1279 &gEfiI2cHostProtocolGuid,
1280 (VOID **) &I2cHost,
1281 This->DriverBindingHandle,
1282 Handle,
1283 EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER
1284 );
1285 return Status;
1286 }
1287
1288 //
1289 // Free resources for this I2C device
1290 //
1291 ReleaseI2cDeviceContext (I2cDeviceContext);
1292
1293 return EFI_SUCCESS;
1294 }
1295
1296 /**
1297 Create a path for the I2C device
1298
1299 Append the I2C slave path to the I2C master controller path.
1300
1301 @param[in] I2cDeviceContext Address of an I2C_DEVICE_CONTEXT structure.
1302 @param[in] BuildControllerNode Flag to build controller node in device path.
1303
1304 @retval EFI_SUCCESS The I2C device path is built successfully.
1305 @return Others It is failed to built device path.
1306
1307 **/
1308 EFI_STATUS
1309 I2cBusDevicePathAppend (
1310 IN I2C_DEVICE_CONTEXT *I2cDeviceContext,
1311 IN BOOLEAN BuildControllerNode
1312 )
1313 {
1314 EFI_DEVICE_PATH_PROTOCOL *PreviousDevicePath;
1315
1316 PreviousDevicePath = NULL;
1317
1318 //
1319 // Build vendor device path
1320 //
1321 CopyMem (&gVendorDevicePathTemplate.Guid, I2cDeviceContext->I2cDevice->DeviceGuid, sizeof (EFI_GUID));
1322 I2cDeviceContext->DevicePath = AppendDevicePathNode (
1323 I2cDeviceContext->I2cBusContext->ParentDevicePath,
1324 (EFI_DEVICE_PATH_PROTOCOL *) &gVendorDevicePathTemplate
1325 );
1326 ASSERT (I2cDeviceContext->DevicePath != NULL);
1327 if (I2cDeviceContext->DevicePath == NULL) {
1328 return EFI_OUT_OF_RESOURCES;
1329 }
1330
1331 if ((BuildControllerNode) && (I2cDeviceContext->DevicePath != NULL)) {
1332 //
1333 // Build the final I2C device path with controller node
1334 //
1335 PreviousDevicePath = I2cDeviceContext->DevicePath;
1336 gControllerDevicePathTemplate.ControllerNumber = I2cDeviceContext->I2cDevice->DeviceIndex;
1337 I2cDeviceContext->DevicePath = AppendDevicePathNode (
1338 I2cDeviceContext->DevicePath,
1339 (EFI_DEVICE_PATH_PROTOCOL *) &gControllerDevicePathTemplate
1340 );
1341 gBS->FreePool (PreviousDevicePath);
1342 ASSERT (I2cDeviceContext->DevicePath != NULL);
1343 if (I2cDeviceContext->DevicePath == NULL) {
1344 return EFI_OUT_OF_RESOURCES;
1345 }
1346 }
1347
1348 return EFI_SUCCESS;
1349 }
1350
1351 /**
1352 The user entry point for the I2C bus module. The user code starts with
1353 this function.
1354
1355 @param[in] ImageHandle The firmware allocated handle for the EFI image.
1356 @param[in] SystemTable A pointer to the EFI System Table.
1357
1358 @retval EFI_SUCCESS The entry point is executed successfully.
1359 @retval other Some error occurs when executing this entry point.
1360
1361 **/
1362 EFI_STATUS
1363 EFIAPI
1364 InitializeI2cBus(
1365 IN EFI_HANDLE ImageHandle,
1366 IN EFI_SYSTEM_TABLE *SystemTable
1367 )
1368 {
1369 EFI_STATUS Status;
1370
1371 //
1372 // Install driver model protocol(s).
1373 //
1374 Status = EfiLibInstallDriverBindingComponentName2 (
1375 ImageHandle,
1376 SystemTable,
1377 &gI2cBusDriverBinding,
1378 NULL,
1379 &gI2cBusComponentName,
1380 &gI2cBusComponentName2
1381 );
1382 ASSERT_EFI_ERROR (Status);
1383
1384
1385 return Status;
1386 }
1387
1388 /**
1389 This is the unload handle for I2C bus module.
1390
1391 Disconnect the driver specified by ImageHandle from all the devices in the handle database.
1392 Uninstall all the protocols installed in the driver entry point.
1393
1394 @param[in] ImageHandle The drivers' driver image.
1395
1396 @retval EFI_SUCCESS The image is unloaded.
1397 @retval Others Failed to unload the image.
1398
1399 **/
1400 EFI_STATUS
1401 EFIAPI
1402 I2cBusUnload (
1403 IN EFI_HANDLE ImageHandle
1404 )
1405 {
1406 EFI_STATUS Status;
1407 EFI_HANDLE *DeviceHandleBuffer;
1408 UINTN DeviceHandleCount;
1409 UINTN Index;
1410 EFI_COMPONENT_NAME_PROTOCOL *ComponentName;
1411 EFI_COMPONENT_NAME2_PROTOCOL *ComponentName2;
1412
1413 //
1414 // Get the list of all I2C Controller handles in the handle database.
1415 // If there is an error getting the list, then the unload
1416 // operation fails.
1417 //
1418 Status = gBS->LocateHandleBuffer (
1419 ByProtocol,
1420 &gEfiI2cHostProtocolGuid,
1421 NULL,
1422 &DeviceHandleCount,
1423 &DeviceHandleBuffer
1424 );
1425
1426 if (!EFI_ERROR (Status)) {
1427 //
1428 // Disconnect the driver specified by Driver BindingHandle from all
1429 // the devices in the handle database.
1430 //
1431 for (Index = 0; Index < DeviceHandleCount; Index++) {
1432 Status = gBS->DisconnectController (
1433 DeviceHandleBuffer[Index],
1434 gI2cBusDriverBinding.DriverBindingHandle,
1435 NULL
1436 );
1437 if (EFI_ERROR (Status)) {
1438 goto Done;
1439 }
1440 }
1441 }
1442
1443 //
1444 // Uninstall all the protocols installed in the driver entry point
1445 //
1446 Status = gBS->UninstallMultipleProtocolInterfaces (
1447 gI2cBusDriverBinding.DriverBindingHandle,
1448 &gEfiDriverBindingProtocolGuid,
1449 &gI2cBusDriverBinding,
1450 NULL
1451 );
1452 ASSERT_EFI_ERROR (Status);
1453
1454 //
1455 // Note we have to one by one uninstall the following protocols.
1456 // It's because some of them are optionally installed based on
1457 // the following PCD settings.
1458 // gEfiMdePkgTokenSpaceGuid.PcdDriverDiagnosticsDisable
1459 // gEfiMdePkgTokenSpaceGuid.PcdComponentNameDisable
1460 // gEfiMdePkgTokenSpaceGuid.PcdDriverDiagnostics2Disable
1461 // gEfiMdePkgTokenSpaceGuid.PcdComponentName2Disable
1462 //
1463 Status = gBS->HandleProtocol (
1464 gI2cBusDriverBinding.DriverBindingHandle,
1465 &gEfiComponentNameProtocolGuid,
1466 (VOID **) &ComponentName
1467 );
1468 if (!EFI_ERROR (Status)) {
1469 gBS->UninstallProtocolInterface (
1470 gI2cBusDriverBinding.DriverBindingHandle,
1471 &gEfiComponentNameProtocolGuid,
1472 ComponentName
1473 );
1474 }
1475
1476 Status = gBS->HandleProtocol (
1477 gI2cBusDriverBinding.DriverBindingHandle,
1478 &gEfiComponentName2ProtocolGuid,
1479 (VOID **) &ComponentName2
1480 );
1481 if (!EFI_ERROR (Status)) {
1482 gBS->UninstallProtocolInterface (
1483 gI2cBusDriverBinding.DriverBindingHandle,
1484 &gEfiComponentName2ProtocolGuid,
1485 ComponentName2
1486 );
1487 }
1488
1489 Status = EFI_SUCCESS;
1490
1491 Done:
1492 //
1493 // Free the buffer containing the list of handles from the handle database
1494 //
1495 if (DeviceHandleBuffer != NULL) {
1496 gBS->FreePool (DeviceHandleBuffer);
1497 }
1498
1499 return Status;
1500 }