xref: /openbmc/linux/include/linux/mhi.h (revision efe47a18)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
4  *
5  */
6 #ifndef _MHI_H_
7 #define _MHI_H_
8 
9 #include <linux/device.h>
10 #include <linux/dma-direction.h>
11 #include <linux/mutex.h>
12 #include <linux/skbuff.h>
13 #include <linux/slab.h>
14 #include <linux/spinlock.h>
15 #include <linux/wait.h>
16 #include <linux/workqueue.h>
17 
18 #define MHI_MAX_OEM_PK_HASH_SEGMENTS 16
19 
20 struct mhi_chan;
21 struct mhi_event;
22 struct mhi_ctxt;
23 struct mhi_cmd;
24 struct mhi_buf_info;
25 
26 /**
27  * enum mhi_callback - MHI callback
28  * @MHI_CB_IDLE: MHI entered idle state
29  * @MHI_CB_PENDING_DATA: New data available for client to process
30  * @MHI_CB_LPM_ENTER: MHI host entered low power mode
31  * @MHI_CB_LPM_EXIT: MHI host about to exit low power mode
32  * @MHI_CB_EE_RDDM: MHI device entered RDDM exec env
33  * @MHI_CB_EE_MISSION_MODE: MHI device entered Mission Mode exec env
34  * @MHI_CB_SYS_ERROR: MHI device entered error state (may recover)
35  * @MHI_CB_FATAL_ERROR: MHI device entered fatal error state
36  * @MHI_CB_BW_REQ: Received a bandwidth switch request from device
37  */
38 enum mhi_callback {
39 	MHI_CB_IDLE,
40 	MHI_CB_PENDING_DATA,
41 	MHI_CB_LPM_ENTER,
42 	MHI_CB_LPM_EXIT,
43 	MHI_CB_EE_RDDM,
44 	MHI_CB_EE_MISSION_MODE,
45 	MHI_CB_SYS_ERROR,
46 	MHI_CB_FATAL_ERROR,
47 	MHI_CB_BW_REQ,
48 };
49 
50 /**
51  * enum mhi_flags - Transfer flags
52  * @MHI_EOB: End of buffer for bulk transfer
53  * @MHI_EOT: End of transfer
54  * @MHI_CHAIN: Linked transfer
55  */
56 enum mhi_flags {
57 	MHI_EOB = BIT(0),
58 	MHI_EOT = BIT(1),
59 	MHI_CHAIN = BIT(2),
60 };
61 
62 /**
63  * enum mhi_device_type - Device types
64  * @MHI_DEVICE_XFER: Handles data transfer
65  * @MHI_DEVICE_CONTROLLER: Control device
66  */
67 enum mhi_device_type {
68 	MHI_DEVICE_XFER,
69 	MHI_DEVICE_CONTROLLER,
70 };
71 
72 /**
73  * enum mhi_ch_type - Channel types
74  * @MHI_CH_TYPE_INVALID: Invalid channel type
75  * @MHI_CH_TYPE_OUTBOUND: Outbound channel to the device
76  * @MHI_CH_TYPE_INBOUND: Inbound channel from the device
77  * @MHI_CH_TYPE_INBOUND_COALESCED: Coalesced channel for the device to combine
78  *				   multiple packets and send them as a single
79  *				   large packet to reduce CPU consumption
80  */
81 enum mhi_ch_type {
82 	MHI_CH_TYPE_INVALID = 0,
83 	MHI_CH_TYPE_OUTBOUND = DMA_TO_DEVICE,
84 	MHI_CH_TYPE_INBOUND = DMA_FROM_DEVICE,
85 	MHI_CH_TYPE_INBOUND_COALESCED = 3,
86 };
87 
88 /**
89  * struct image_info - Firmware and RDDM table
90  * @mhi_buf: Buffer for firmware and RDDM table
91  * @entries: # of entries in table
92  */
93 struct image_info {
94 	struct mhi_buf *mhi_buf;
95 	/* private: from internal.h */
96 	struct bhi_vec_entry *bhi_vec;
97 	/* public: */
98 	u32 entries;
99 };
100 
101 /**
102  * struct mhi_link_info - BW requirement
103  * target_link_speed - Link speed as defined by TLS bits in LinkControl reg
104  * target_link_width - Link width as defined by NLW bits in LinkStatus reg
105  */
106 struct mhi_link_info {
107 	unsigned int target_link_speed;
108 	unsigned int target_link_width;
109 };
110 
111 /**
112  * enum mhi_ee_type - Execution environment types
113  * @MHI_EE_PBL: Primary Bootloader
114  * @MHI_EE_SBL: Secondary Bootloader
115  * @MHI_EE_AMSS: Modem, aka the primary runtime EE
116  * @MHI_EE_RDDM: Ram dump download mode
117  * @MHI_EE_WFW: WLAN firmware mode
118  * @MHI_EE_PTHRU: Passthrough
119  * @MHI_EE_EDL: Embedded downloader
120  * @MHI_EE_FP: Flash Programmer Environment
121  */
122 enum mhi_ee_type {
123 	MHI_EE_PBL,
124 	MHI_EE_SBL,
125 	MHI_EE_AMSS,
126 	MHI_EE_RDDM,
127 	MHI_EE_WFW,
128 	MHI_EE_PTHRU,
129 	MHI_EE_EDL,
130 	MHI_EE_FP,
131 	MHI_EE_MAX_SUPPORTED = MHI_EE_FP,
132 	MHI_EE_DISABLE_TRANSITION, /* local EE, not related to mhi spec */
133 	MHI_EE_NOT_SUPPORTED,
134 	MHI_EE_MAX,
135 };
136 
137 /**
138  * enum mhi_state - MHI states
139  * @MHI_STATE_RESET: Reset state
140  * @MHI_STATE_READY: Ready state
141  * @MHI_STATE_M0: M0 state
142  * @MHI_STATE_M1: M1 state
143  * @MHI_STATE_M2: M2 state
144  * @MHI_STATE_M3: M3 state
145  * @MHI_STATE_M3_FAST: M3 Fast state
146  * @MHI_STATE_BHI: BHI state
147  * @MHI_STATE_SYS_ERR: System Error state
148  */
149 enum mhi_state {
150 	MHI_STATE_RESET = 0x0,
151 	MHI_STATE_READY = 0x1,
152 	MHI_STATE_M0 = 0x2,
153 	MHI_STATE_M1 = 0x3,
154 	MHI_STATE_M2 = 0x4,
155 	MHI_STATE_M3 = 0x5,
156 	MHI_STATE_M3_FAST = 0x6,
157 	MHI_STATE_BHI = 0x7,
158 	MHI_STATE_SYS_ERR = 0xFF,
159 	MHI_STATE_MAX,
160 };
161 
162 /**
163  * enum mhi_ch_ee_mask - Execution environment mask for channel
164  * @MHI_CH_EE_PBL: Allow channel to be used in PBL EE
165  * @MHI_CH_EE_SBL: Allow channel to be used in SBL EE
166  * @MHI_CH_EE_AMSS: Allow channel to be used in AMSS EE
167  * @MHI_CH_EE_RDDM: Allow channel to be used in RDDM EE
168  * @MHI_CH_EE_PTHRU: Allow channel to be used in PTHRU EE
169  * @MHI_CH_EE_WFW: Allow channel to be used in WFW EE
170  * @MHI_CH_EE_EDL: Allow channel to be used in EDL EE
171  */
172 enum mhi_ch_ee_mask {
173 	MHI_CH_EE_PBL = BIT(MHI_EE_PBL),
174 	MHI_CH_EE_SBL = BIT(MHI_EE_SBL),
175 	MHI_CH_EE_AMSS = BIT(MHI_EE_AMSS),
176 	MHI_CH_EE_RDDM = BIT(MHI_EE_RDDM),
177 	MHI_CH_EE_PTHRU = BIT(MHI_EE_PTHRU),
178 	MHI_CH_EE_WFW = BIT(MHI_EE_WFW),
179 	MHI_CH_EE_EDL = BIT(MHI_EE_EDL),
180 };
181 
182 /**
183  * enum mhi_er_data_type - Event ring data types
184  * @MHI_ER_DATA: Only client data over this ring
185  * @MHI_ER_CTRL: MHI control data and client data
186  */
187 enum mhi_er_data_type {
188 	MHI_ER_DATA,
189 	MHI_ER_CTRL,
190 };
191 
192 /**
193  * enum mhi_db_brst_mode - Doorbell mode
194  * @MHI_DB_BRST_DISABLE: Burst mode disable
195  * @MHI_DB_BRST_ENABLE: Burst mode enable
196  */
197 enum mhi_db_brst_mode {
198 	MHI_DB_BRST_DISABLE = 0x2,
199 	MHI_DB_BRST_ENABLE = 0x3,
200 };
201 
202 /**
203  * struct mhi_channel_config - Channel configuration structure for controller
204  * @name: The name of this channel
205  * @num: The number assigned to this channel
206  * @num_elements: The number of elements that can be queued to this channel
207  * @local_elements: The local ring length of the channel
208  * @event_ring: The event ring index that services this channel
209  * @dir: Direction that data may flow on this channel
210  * @type: Channel type
211  * @ee_mask: Execution Environment mask for this channel
212  * @pollcfg: Polling configuration for burst mode.  0 is default.  milliseconds
213 	     for UL channels, multiple of 8 ring elements for DL channels
214  * @doorbell: Doorbell mode
215  * @lpm_notify: The channel master requires low power mode notifications
216  * @offload_channel: The client manages the channel completely
217  * @doorbell_mode_switch: Channel switches to doorbell mode on M0 transition
218  * @auto_queue: Framework will automatically queue buffers for DL traffic
219  * @wake-capable: Channel capable of waking up the system
220  */
221 struct mhi_channel_config {
222 	char *name;
223 	u32 num;
224 	u32 num_elements;
225 	u32 local_elements;
226 	u32 event_ring;
227 	enum dma_data_direction dir;
228 	enum mhi_ch_type type;
229 	u32 ee_mask;
230 	u32 pollcfg;
231 	enum mhi_db_brst_mode doorbell;
232 	bool lpm_notify;
233 	bool offload_channel;
234 	bool doorbell_mode_switch;
235 	bool auto_queue;
236 	bool wake_capable;
237 };
238 
239 /**
240  * struct mhi_event_config - Event ring configuration structure for controller
241  * @num_elements: The number of elements that can be queued to this ring
242  * @irq_moderation_ms: Delay irq for additional events to be aggregated
243  * @irq: IRQ associated with this ring
244  * @channel: Dedicated channel number. U32_MAX indicates a non-dedicated ring
245  * @priority: Priority of this ring. Use 1 for now
246  * @mode: Doorbell mode
247  * @data_type: Type of data this ring will process
248  * @hardware_event: This ring is associated with hardware channels
249  * @client_managed: This ring is client managed
250  * @offload_channel: This ring is associated with an offloaded channel
251  */
252 struct mhi_event_config {
253 	u32 num_elements;
254 	u32 irq_moderation_ms;
255 	u32 irq;
256 	u32 channel;
257 	u32 priority;
258 	enum mhi_db_brst_mode mode;
259 	enum mhi_er_data_type data_type;
260 	bool hardware_event;
261 	bool client_managed;
262 	bool offload_channel;
263 };
264 
265 /**
266  * struct mhi_controller_config - Root MHI controller configuration
267  * @max_channels: Maximum number of channels supported
268  * @timeout_ms: Timeout value for operations. 0 means use default
269  * @buf_len: Size of automatically allocated buffers. 0 means use default
270  * @num_channels: Number of channels defined in @ch_cfg
271  * @ch_cfg: Array of defined channels
272  * @num_events: Number of event rings defined in @event_cfg
273  * @event_cfg: Array of defined event rings
274  * @use_bounce_buf: Use a bounce buffer pool due to limited DDR access
275  * @m2_no_db: Host is not allowed to ring DB in M2 state
276  */
277 struct mhi_controller_config {
278 	u32 max_channels;
279 	u32 timeout_ms;
280 	u32 buf_len;
281 	u32 num_channels;
282 	const struct mhi_channel_config *ch_cfg;
283 	u32 num_events;
284 	struct mhi_event_config *event_cfg;
285 	bool use_bounce_buf;
286 	bool m2_no_db;
287 };
288 
289 /**
290  * struct mhi_controller - Master MHI controller structure
291  * @cntrl_dev: Pointer to the struct device of physical bus acting as the MHI
292  *            controller (required)
293  * @mhi_dev: MHI device instance for the controller
294  * @debugfs_dentry: MHI controller debugfs directory
295  * @regs: Base address of MHI MMIO register space (required)
296  * @bhi: Points to base of MHI BHI register space
297  * @bhie: Points to base of MHI BHIe register space
298  * @wake_db: MHI WAKE doorbell register address
299  * @iova_start: IOMMU starting address for data (required)
300  * @iova_stop: IOMMU stop address for data (required)
301  * @fw_image: Firmware image name for normal booting (optional)
302  * @fw_data: Firmware image data content for normal booting, used only
303  *           if fw_image is NULL and fbc_download is true (optional)
304  * @fw_sz: Firmware image data size for normal booting, used only if fw_image
305  *         is NULL and fbc_download is true (optional)
306  * @edl_image: Firmware image name for emergency download mode (optional)
307  * @rddm_size: RAM dump size that host should allocate for debugging purpose
308  * @sbl_size: SBL image size downloaded through BHIe (optional)
309  * @seg_len: BHIe vector size (optional)
310  * @reg_len: Length of the MHI MMIO region (required)
311  * @fbc_image: Points to firmware image buffer
312  * @rddm_image: Points to RAM dump buffer
313  * @mhi_chan: Points to the channel configuration table
314  * @lpm_chans: List of channels that require LPM notifications
315  * @irq: base irq # to request (required)
316  * @max_chan: Maximum number of channels the controller supports
317  * @total_ev_rings: Total # of event rings allocated
318  * @hw_ev_rings: Number of hardware event rings
319  * @sw_ev_rings: Number of software event rings
320  * @nr_irqs: Number of IRQ allocated by bus master (required)
321  * @family_number: MHI controller family number
322  * @device_number: MHI controller device number
323  * @major_version: MHI controller major revision number
324  * @minor_version: MHI controller minor revision number
325  * @serial_number: MHI controller serial number obtained from BHI
326  * @oem_pk_hash: MHI controller OEM PK Hash obtained from BHI
327  * @mhi_event: MHI event ring configurations table
328  * @mhi_cmd: MHI command ring configurations table
329  * @mhi_ctxt: MHI device context, shared memory between host and device
330  * @pm_mutex: Mutex for suspend/resume operation
331  * @pm_lock: Lock for protecting MHI power management state
332  * @timeout_ms: Timeout in ms for state transitions
333  * @pm_state: MHI power management state
334  * @db_access: DB access states
335  * @ee: MHI device execution environment
336  * @dev_state: MHI device state
337  * @dev_wake: Device wakeup count
338  * @pending_pkts: Pending packets for the controller
339  * @M0, M2, M3: Counters to track number of device MHI state changes
340  * @transition_list: List of MHI state transitions
341  * @transition_lock: Lock for protecting MHI state transition list
342  * @wlock: Lock for protecting device wakeup
343  * @mhi_link_info: Device bandwidth info
344  * @st_worker: State transition worker
345  * @hiprio_wq: High priority workqueue for MHI work such as state transitions
346  * @state_event: State change event
347  * @status_cb: CB function to notify power states of the device (required)
348  * @wake_get: CB function to assert device wake (optional)
349  * @wake_put: CB function to de-assert device wake (optional)
350  * @wake_toggle: CB function to assert and de-assert device wake (optional)
351  * @runtime_get: CB function to controller runtime resume (required)
352  * @runtime_put: CB function to decrement pm usage (required)
353  * @map_single: CB function to create TRE buffer
354  * @unmap_single: CB function to destroy TRE buffer
355  * @read_reg: Read a MHI register via the physical link (required)
356  * @write_reg: Write a MHI register via the physical link (required)
357  * @reset: Controller specific reset function (optional)
358  * @buffer_len: Bounce buffer length
359  * @index: Index of the MHI controller instance
360  * @bounce_buf: Use of bounce buffer
361  * @fbc_download: MHI host needs to do complete image transfer (optional)
362  * @wake_set: Device wakeup set flag
363  * @irq_flags: irq flags passed to request_irq (optional)
364  * @mru: the default MRU for the MHI device
365  *
366  * Fields marked as (required) need to be populated by the controller driver
367  * before calling mhi_register_controller(). For the fields marked as (optional)
368  * they can be populated depending on the usecase.
369  *
370  * The following fields are present for the purpose of implementing any device
371  * specific quirks or customizations for specific MHI revisions used in device
372  * by the controller drivers. The MHI stack will just populate these fields
373  * during mhi_register_controller():
374  *  family_number
375  *  device_number
376  *  major_version
377  *  minor_version
378  */
379 struct mhi_controller {
380 	struct device *cntrl_dev;
381 	struct mhi_device *mhi_dev;
382 	struct dentry *debugfs_dentry;
383 	void __iomem *regs;
384 	void __iomem *bhi;
385 	void __iomem *bhie;
386 	void __iomem *wake_db;
387 
388 	dma_addr_t iova_start;
389 	dma_addr_t iova_stop;
390 	const char *fw_image;
391 	const u8 *fw_data;
392 	size_t fw_sz;
393 	const char *edl_image;
394 	size_t rddm_size;
395 	size_t sbl_size;
396 	size_t seg_len;
397 	size_t reg_len;
398 	struct image_info *fbc_image;
399 	struct image_info *rddm_image;
400 	struct mhi_chan *mhi_chan;
401 	struct list_head lpm_chans;
402 	int *irq;
403 	u32 max_chan;
404 	u32 total_ev_rings;
405 	u32 hw_ev_rings;
406 	u32 sw_ev_rings;
407 	u32 nr_irqs;
408 	u32 family_number;
409 	u32 device_number;
410 	u32 major_version;
411 	u32 minor_version;
412 	u32 serial_number;
413 	u32 oem_pk_hash[MHI_MAX_OEM_PK_HASH_SEGMENTS];
414 
415 	struct mhi_event *mhi_event;
416 	struct mhi_cmd *mhi_cmd;
417 	struct mhi_ctxt *mhi_ctxt;
418 
419 	struct mutex pm_mutex;
420 	rwlock_t pm_lock;
421 	u32 timeout_ms;
422 	u32 pm_state;
423 	u32 db_access;
424 	enum mhi_ee_type ee;
425 	enum mhi_state dev_state;
426 	atomic_t dev_wake;
427 	atomic_t pending_pkts;
428 	u32 M0, M2, M3;
429 	struct list_head transition_list;
430 	spinlock_t transition_lock;
431 	spinlock_t wlock;
432 	struct mhi_link_info mhi_link_info;
433 	struct work_struct st_worker;
434 	struct workqueue_struct *hiprio_wq;
435 	wait_queue_head_t state_event;
436 
437 	void (*status_cb)(struct mhi_controller *mhi_cntrl,
438 			  enum mhi_callback cb);
439 	void (*wake_get)(struct mhi_controller *mhi_cntrl, bool override);
440 	void (*wake_put)(struct mhi_controller *mhi_cntrl, bool override);
441 	void (*wake_toggle)(struct mhi_controller *mhi_cntrl);
442 	int (*runtime_get)(struct mhi_controller *mhi_cntrl);
443 	void (*runtime_put)(struct mhi_controller *mhi_cntrl);
444 	int (*map_single)(struct mhi_controller *mhi_cntrl,
445 			  struct mhi_buf_info *buf);
446 	void (*unmap_single)(struct mhi_controller *mhi_cntrl,
447 			     struct mhi_buf_info *buf);
448 	int (*read_reg)(struct mhi_controller *mhi_cntrl, void __iomem *addr,
449 			u32 *out);
450 	void (*write_reg)(struct mhi_controller *mhi_cntrl, void __iomem *addr,
451 			  u32 val);
452 	void (*reset)(struct mhi_controller *mhi_cntrl);
453 
454 	size_t buffer_len;
455 	int index;
456 	bool bounce_buf;
457 	bool fbc_download;
458 	bool wake_set;
459 	unsigned long irq_flags;
460 	u32 mru;
461 };
462 
463 /**
464  * struct mhi_device - Structure representing an MHI device which binds
465  *                     to channels or is associated with controllers
466  * @id: Pointer to MHI device ID struct
467  * @name: Name of the associated MHI device
468  * @mhi_cntrl: Controller the device belongs to
469  * @ul_chan: UL channel for the device
470  * @dl_chan: DL channel for the device
471  * @dev: Driver model device node for the MHI device
472  * @dev_type: MHI device type
473  * @ul_chan_id: MHI channel id for UL transfer
474  * @dl_chan_id: MHI channel id for DL transfer
475  * @dev_wake: Device wakeup counter
476  */
477 struct mhi_device {
478 	const struct mhi_device_id *id;
479 	const char *name;
480 	struct mhi_controller *mhi_cntrl;
481 	struct mhi_chan *ul_chan;
482 	struct mhi_chan *dl_chan;
483 	struct device dev;
484 	enum mhi_device_type dev_type;
485 	int ul_chan_id;
486 	int dl_chan_id;
487 	u32 dev_wake;
488 };
489 
490 /**
491  * struct mhi_result - Completed buffer information
492  * @buf_addr: Address of data buffer
493  * @bytes_xferd: # of bytes transferred
494  * @dir: Channel direction
495  * @transaction_status: Status of last transaction
496  */
497 struct mhi_result {
498 	void *buf_addr;
499 	size_t bytes_xferd;
500 	enum dma_data_direction dir;
501 	int transaction_status;
502 };
503 
504 /**
505  * struct mhi_buf - MHI Buffer description
506  * @buf: Virtual address of the buffer
507  * @name: Buffer label. For offload channel, configurations name must be:
508  *        ECA - Event context array data
509  *        CCA - Channel context array data
510  * @dma_addr: IOMMU address of the buffer
511  * @len: # of bytes
512  */
513 struct mhi_buf {
514 	void *buf;
515 	const char *name;
516 	dma_addr_t dma_addr;
517 	size_t len;
518 };
519 
520 /**
521  * struct mhi_driver - Structure representing a MHI client driver
522  * @probe: CB function for client driver probe function
523  * @remove: CB function for client driver remove function
524  * @ul_xfer_cb: CB function for UL data transfer
525  * @dl_xfer_cb: CB function for DL data transfer
526  * @status_cb: CB functions for asynchronous status
527  * @driver: Device driver model driver
528  */
529 struct mhi_driver {
530 	const struct mhi_device_id *id_table;
531 	int (*probe)(struct mhi_device *mhi_dev,
532 		     const struct mhi_device_id *id);
533 	void (*remove)(struct mhi_device *mhi_dev);
534 	void (*ul_xfer_cb)(struct mhi_device *mhi_dev,
535 			   struct mhi_result *result);
536 	void (*dl_xfer_cb)(struct mhi_device *mhi_dev,
537 			   struct mhi_result *result);
538 	void (*status_cb)(struct mhi_device *mhi_dev, enum mhi_callback mhi_cb);
539 	struct device_driver driver;
540 };
541 
542 #define to_mhi_driver(drv) container_of(drv, struct mhi_driver, driver)
543 #define to_mhi_device(dev) container_of(dev, struct mhi_device, dev)
544 
545 /**
546  * mhi_alloc_controller - Allocate the MHI Controller structure
547  * Allocate the mhi_controller structure using zero initialized memory
548  */
549 struct mhi_controller *mhi_alloc_controller(void);
550 
551 /**
552  * mhi_free_controller - Free the MHI Controller structure
553  * Free the mhi_controller structure which was previously allocated
554  */
555 void mhi_free_controller(struct mhi_controller *mhi_cntrl);
556 
557 /**
558  * mhi_register_controller - Register MHI controller
559  * @mhi_cntrl: MHI controller to register
560  * @config: Configuration to use for the controller
561  */
562 int mhi_register_controller(struct mhi_controller *mhi_cntrl,
563 			const struct mhi_controller_config *config);
564 
565 /**
566  * mhi_unregister_controller - Unregister MHI controller
567  * @mhi_cntrl: MHI controller to unregister
568  */
569 void mhi_unregister_controller(struct mhi_controller *mhi_cntrl);
570 
571 /*
572  * module_mhi_driver() - Helper macro for drivers that don't do
573  * anything special other than using default mhi_driver_register() and
574  * mhi_driver_unregister().  This eliminates a lot of boilerplate.
575  * Each module may only use this macro once.
576  */
577 #define module_mhi_driver(mhi_drv) \
578 	module_driver(mhi_drv, mhi_driver_register, \
579 		      mhi_driver_unregister)
580 
581 /*
582  * Macro to avoid include chaining to get THIS_MODULE
583  */
584 #define mhi_driver_register(mhi_drv) \
585 	__mhi_driver_register(mhi_drv, THIS_MODULE)
586 
587 /**
588  * __mhi_driver_register - Register driver with MHI framework
589  * @mhi_drv: Driver associated with the device
590  * @owner: The module owner
591  */
592 int __mhi_driver_register(struct mhi_driver *mhi_drv, struct module *owner);
593 
594 /**
595  * mhi_driver_unregister - Unregister a driver for mhi_devices
596  * @mhi_drv: Driver associated with the device
597  */
598 void mhi_driver_unregister(struct mhi_driver *mhi_drv);
599 
600 /**
601  * mhi_set_mhi_state - Set MHI device state
602  * @mhi_cntrl: MHI controller
603  * @state: State to set
604  */
605 void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl,
606 		       enum mhi_state state);
607 
608 /**
609  * mhi_notify - Notify the MHI client driver about client device status
610  * @mhi_dev: MHI device instance
611  * @cb_reason: MHI callback reason
612  */
613 void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason);
614 
615 /**
616  * mhi_get_free_desc_count - Get transfer ring length
617  * Get # of TD available to queue buffers
618  * @mhi_dev: Device associated with the channels
619  * @dir: Direction of the channel
620  */
621 int mhi_get_free_desc_count(struct mhi_device *mhi_dev,
622 				enum dma_data_direction dir);
623 
624 /**
625  * mhi_prepare_for_power_up - Do pre-initialization before power up.
626  *                            This is optional, call this before power up if
627  *                            the controller does not want bus framework to
628  *                            automatically free any allocated memory during
629  *                            shutdown process.
630  * @mhi_cntrl: MHI controller
631  */
632 int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl);
633 
634 /**
635  * mhi_async_power_up - Start MHI power up sequence
636  * @mhi_cntrl: MHI controller
637  */
638 int mhi_async_power_up(struct mhi_controller *mhi_cntrl);
639 
640 /**
641  * mhi_sync_power_up - Start MHI power up sequence and wait till the device
642  *                     enters valid EE state
643  * @mhi_cntrl: MHI controller
644  */
645 int mhi_sync_power_up(struct mhi_controller *mhi_cntrl);
646 
647 /**
648  * mhi_power_down - Start MHI power down sequence
649  * @mhi_cntrl: MHI controller
650  * @graceful: Link is still accessible, so do a graceful shutdown process
651  */
652 void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful);
653 
654 /**
655  * mhi_unprepare_after_power_down - Free any allocated memory after power down
656  * @mhi_cntrl: MHI controller
657  */
658 void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl);
659 
660 /**
661  * mhi_pm_suspend - Move MHI into a suspended state
662  * @mhi_cntrl: MHI controller
663  */
664 int mhi_pm_suspend(struct mhi_controller *mhi_cntrl);
665 
666 /**
667  * mhi_pm_resume - Resume MHI from suspended state
668  * @mhi_cntrl: MHI controller
669  */
670 int mhi_pm_resume(struct mhi_controller *mhi_cntrl);
671 
672 /**
673  * mhi_pm_resume_force - Force resume MHI from suspended state
674  * @mhi_cntrl: MHI controller
675  *
676  * Resume the device irrespective of its MHI state. As per the MHI spec, devices
677  * has to be in M3 state during resume. But some devices seem to be in a
678  * different MHI state other than M3 but they continue working fine if allowed.
679  * This API is intented to be used for such devices.
680  *
681  * Return: 0 if the resume succeeds, a negative error code otherwise
682  */
683 int mhi_pm_resume_force(struct mhi_controller *mhi_cntrl);
684 
685 /**
686  * mhi_download_rddm_image - Download ramdump image from device for
687  *                           debugging purpose.
688  * @mhi_cntrl: MHI controller
689  * @in_panic: Download rddm image during kernel panic
690  */
691 int mhi_download_rddm_image(struct mhi_controller *mhi_cntrl, bool in_panic);
692 
693 /**
694  * mhi_force_rddm_mode - Force device into rddm mode
695  * @mhi_cntrl: MHI controller
696  */
697 int mhi_force_rddm_mode(struct mhi_controller *mhi_cntrl);
698 
699 /**
700  * mhi_get_exec_env - Get BHI execution environment of the device
701  * @mhi_cntrl: MHI controller
702  */
703 enum mhi_ee_type mhi_get_exec_env(struct mhi_controller *mhi_cntrl);
704 
705 /**
706  * mhi_get_mhi_state - Get MHI state of the device
707  * @mhi_cntrl: MHI controller
708  */
709 enum mhi_state mhi_get_mhi_state(struct mhi_controller *mhi_cntrl);
710 
711 /**
712  * mhi_soc_reset - Trigger a device reset. This can be used as a last resort
713  *		   to reset and recover a device.
714  * @mhi_cntrl: MHI controller
715  */
716 void mhi_soc_reset(struct mhi_controller *mhi_cntrl);
717 
718 /**
719  * mhi_device_get - Disable device low power mode
720  * @mhi_dev: Device associated with the channel
721  */
722 void mhi_device_get(struct mhi_device *mhi_dev);
723 
724 /**
725  * mhi_device_get_sync - Disable device low power mode. Synchronously
726  *                       take the controller out of suspended state
727  * @mhi_dev: Device associated with the channel
728  */
729 int mhi_device_get_sync(struct mhi_device *mhi_dev);
730 
731 /**
732  * mhi_device_put - Re-enable device low power mode
733  * @mhi_dev: Device associated with the channel
734  */
735 void mhi_device_put(struct mhi_device *mhi_dev);
736 
737 /**
738  * mhi_prepare_for_transfer - Setup UL and DL channels for data transfer.
739  * @mhi_dev: Device associated with the channels
740  *
741  * Allocate and initialize the channel context and also issue the START channel
742  * command to both channels. Channels can be started only if both host and
743  * device execution environments match and channels are in a DISABLED state.
744  */
745 int mhi_prepare_for_transfer(struct mhi_device *mhi_dev);
746 
747 /**
748  * mhi_prepare_for_transfer_autoqueue - Setup UL and DL channels with auto queue
749  *                                      buffers for DL traffic
750  * @mhi_dev: Device associated with the channels
751  *
752  * Allocate and initialize the channel context and also issue the START channel
753  * command to both channels. Channels can be started only if both host and
754  * device execution environments match and channels are in a DISABLED state.
755  * The MHI core will automatically allocate and queue buffers for the DL traffic.
756  */
757 int mhi_prepare_for_transfer_autoqueue(struct mhi_device *mhi_dev);
758 
759 /**
760  * mhi_unprepare_from_transfer - Reset UL and DL channels for data transfer.
761  *                               Issue the RESET channel command and let the
762  *                               device clean-up the context so no incoming
763  *                               transfers are seen on the host. Free memory
764  *                               associated with the context on host. If device
765  *                               is unresponsive, only perform a host side
766  *                               clean-up. Channels can be reset only if both
767  *                               host and device execution environments match
768  *                               and channels are in an ENABLED, STOPPED or
769  *                               SUSPENDED state.
770  * @mhi_dev: Device associated with the channels
771  */
772 void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev);
773 
774 /**
775  * mhi_queue_dma - Send or receive DMA mapped buffers from client device
776  *                 over MHI channel
777  * @mhi_dev: Device associated with the channels
778  * @dir: DMA direction for the channel
779  * @mhi_buf: Buffer for holding the DMA mapped data
780  * @len: Buffer length
781  * @mflags: MHI transfer flags used for the transfer
782  */
783 int mhi_queue_dma(struct mhi_device *mhi_dev, enum dma_data_direction dir,
784 		  struct mhi_buf *mhi_buf, size_t len, enum mhi_flags mflags);
785 
786 /**
787  * mhi_queue_buf - Send or receive raw buffers from client device over MHI
788  *                 channel
789  * @mhi_dev: Device associated with the channels
790  * @dir: DMA direction for the channel
791  * @buf: Buffer for holding the data
792  * @len: Buffer length
793  * @mflags: MHI transfer flags used for the transfer
794  */
795 int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir,
796 		  void *buf, size_t len, enum mhi_flags mflags);
797 
798 /**
799  * mhi_queue_skb - Send or receive SKBs from client device over MHI channel
800  * @mhi_dev: Device associated with the channels
801  * @dir: DMA direction for the channel
802  * @skb: Buffer for holding SKBs
803  * @len: Buffer length
804  * @mflags: MHI transfer flags used for the transfer
805  */
806 int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir,
807 		  struct sk_buff *skb, size_t len, enum mhi_flags mflags);
808 
809 /**
810  * mhi_queue_is_full - Determine whether queueing new elements is possible
811  * @mhi_dev: Device associated with the channels
812  * @dir: DMA direction for the channel
813  */
814 bool mhi_queue_is_full(struct mhi_device *mhi_dev, enum dma_data_direction dir);
815 
816 #endif /* _MHI_H_ */
817