xref: /linux/include/linux/mhi.h (revision 889600e21e3be388a6817c2a0dac0411df860751)
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 #include <linux/device-id/mhi.h>
18 
19 #define MHI_MAX_OEM_PK_HASH_SEGMENTS 16
20 
21 struct mhi_chan;
22 struct mhi_event;
23 struct mhi_ctxt;
24 struct mhi_cmd;
25 struct mhi_buf_info;
26 
27 /**
28  * enum mhi_callback - MHI callback
29  * @MHI_CB_IDLE: MHI entered idle state
30  * @MHI_CB_PENDING_DATA: New data available for client to process
31  * @MHI_CB_LPM_ENTER: MHI host entered low power mode
32  * @MHI_CB_LPM_EXIT: MHI host about to exit low power mode
33  * @MHI_CB_EE_RDDM: MHI device entered RDDM exec env
34  * @MHI_CB_EE_MISSION_MODE: MHI device entered Mission Mode exec env
35  * @MHI_CB_SYS_ERROR: MHI device entered error state (may recover)
36  * @MHI_CB_FATAL_ERROR: MHI device entered fatal error state
37  * @MHI_CB_BW_REQ: Received a bandwidth switch request from device
38  */
39 enum mhi_callback {
40 	MHI_CB_IDLE,
41 	MHI_CB_PENDING_DATA,
42 	MHI_CB_LPM_ENTER,
43 	MHI_CB_LPM_EXIT,
44 	MHI_CB_EE_RDDM,
45 	MHI_CB_EE_MISSION_MODE,
46 	MHI_CB_SYS_ERROR,
47 	MHI_CB_FATAL_ERROR,
48 	MHI_CB_BW_REQ,
49 };
50 
51 /**
52  * enum mhi_flags - Transfer flags
53  * @MHI_EOB: End of buffer for bulk transfer
54  * @MHI_EOT: End of transfer
55  * @MHI_CHAIN: Linked transfer
56  */
57 enum mhi_flags {
58 	MHI_EOB = BIT(0),
59 	MHI_EOT = BIT(1),
60 	MHI_CHAIN = BIT(2),
61 };
62 
63 /**
64  * enum mhi_device_type - Device types
65  * @MHI_DEVICE_XFER: Handles data transfer
66  * @MHI_DEVICE_CONTROLLER: Control device
67  */
68 enum mhi_device_type {
69 	MHI_DEVICE_XFER,
70 	MHI_DEVICE_CONTROLLER,
71 };
72 
73 /**
74  * enum mhi_ch_type - Channel types
75  * @MHI_CH_TYPE_INVALID: Invalid channel type
76  * @MHI_CH_TYPE_OUTBOUND: Outbound channel to the device
77  * @MHI_CH_TYPE_INBOUND: Inbound channel from the device
78  * @MHI_CH_TYPE_INBOUND_COALESCED: Coalesced channel for the device to combine
79  *				   multiple packets and send them as a single
80  *				   large packet to reduce CPU consumption
81  */
82 enum mhi_ch_type {
83 	MHI_CH_TYPE_INVALID = 0,
84 	MHI_CH_TYPE_OUTBOUND = DMA_TO_DEVICE,
85 	MHI_CH_TYPE_INBOUND = DMA_FROM_DEVICE,
86 	MHI_CH_TYPE_INBOUND_COALESCED = 3,
87 };
88 
89 /**
90  * struct mhi_buf - MHI Buffer description
91  * @buf: Virtual address of the buffer
92  * @name: Buffer label. For offload channel, configurations name must be:
93  *        ECA - Event context array data
94  *        CCA - Channel context array data
95  * @dma_addr: IOMMU address of the buffer
96  * @len: # of bytes
97  */
98 struct mhi_buf {
99 	void *buf;
100 	const char *name;
101 	dma_addr_t dma_addr;
102 	size_t len;
103 };
104 
105 /**
106  * struct image_info - Firmware and RDDM table
107  * @mhi_buf: Buffer for firmware and RDDM table
108  * @entries: # of entries in table
109  */
110 struct image_info {
111 	/* private: from internal.h */
112 	struct bhi_vec_entry *bhi_vec;
113 	/* public: */
114 	u32 entries;
115 	struct mhi_buf mhi_buf[] __counted_by(entries);
116 };
117 
118 /**
119  * struct mhi_link_info - BW requirement
120  * @target_link_speed: Link speed as defined by TLS bits in LinkControl reg
121  * @target_link_width: Link width as defined by NLW bits in LinkStatus reg
122  */
123 struct mhi_link_info {
124 	unsigned int target_link_speed;
125 	unsigned int target_link_width;
126 };
127 
128 /**
129  * enum mhi_ee_type - Execution environment types
130  * @MHI_EE_PBL: Primary Bootloader
131  * @MHI_EE_SBL: Secondary Bootloader
132  * @MHI_EE_AMSS: Modem, aka the primary runtime EE
133  * @MHI_EE_RDDM: Ram dump download mode
134  * @MHI_EE_WFW: WLAN firmware mode
135  * @MHI_EE_PTHRU: Passthrough
136  * @MHI_EE_EDL: Embedded downloader
137  * @MHI_EE_FP: Flash Programmer Environment
138  */
139 enum mhi_ee_type {
140 	MHI_EE_PBL,
141 	MHI_EE_SBL,
142 	MHI_EE_AMSS,
143 	MHI_EE_RDDM,
144 	MHI_EE_WFW,
145 	MHI_EE_PTHRU,
146 	MHI_EE_EDL,
147 	MHI_EE_FP,
148 	MHI_EE_MAX_SUPPORTED = MHI_EE_FP,
149 	MHI_EE_DISABLE_TRANSITION, /* local EE, not related to mhi spec */
150 	MHI_EE_NOT_SUPPORTED,
151 	MHI_EE_MAX,
152 };
153 
154 /**
155  * enum mhi_state - MHI states
156  * @MHI_STATE_RESET: Reset state
157  * @MHI_STATE_READY: Ready state
158  * @MHI_STATE_M0: M0 state
159  * @MHI_STATE_M1: M1 state
160  * @MHI_STATE_M2: M2 state
161  * @MHI_STATE_M3: M3 state
162  * @MHI_STATE_M3_FAST: M3 Fast state
163  * @MHI_STATE_BHI: BHI state
164  * @MHI_STATE_SYS_ERR: System Error state
165  */
166 enum mhi_state {
167 	MHI_STATE_RESET = 0x0,
168 	MHI_STATE_READY = 0x1,
169 	MHI_STATE_M0 = 0x2,
170 	MHI_STATE_M1 = 0x3,
171 	MHI_STATE_M2 = 0x4,
172 	MHI_STATE_M3 = 0x5,
173 	MHI_STATE_M3_FAST = 0x6,
174 	MHI_STATE_BHI = 0x7,
175 	MHI_STATE_SYS_ERR = 0xFF,
176 	/* private: */
177 	MHI_STATE_MAX,
178 };
179 
180 /**
181  * enum mhi_ch_ee_mask - Execution environment mask for channel
182  * @MHI_CH_EE_PBL: Allow channel to be used in PBL EE
183  * @MHI_CH_EE_SBL: Allow channel to be used in SBL EE
184  * @MHI_CH_EE_AMSS: Allow channel to be used in AMSS EE
185  * @MHI_CH_EE_RDDM: Allow channel to be used in RDDM EE
186  * @MHI_CH_EE_PTHRU: Allow channel to be used in PTHRU EE
187  * @MHI_CH_EE_WFW: Allow channel to be used in WFW EE
188  * @MHI_CH_EE_EDL: Allow channel to be used in EDL EE
189  */
190 enum mhi_ch_ee_mask {
191 	MHI_CH_EE_PBL = BIT(MHI_EE_PBL),
192 	MHI_CH_EE_SBL = BIT(MHI_EE_SBL),
193 	MHI_CH_EE_AMSS = BIT(MHI_EE_AMSS),
194 	MHI_CH_EE_RDDM = BIT(MHI_EE_RDDM),
195 	MHI_CH_EE_PTHRU = BIT(MHI_EE_PTHRU),
196 	MHI_CH_EE_WFW = BIT(MHI_EE_WFW),
197 	MHI_CH_EE_EDL = BIT(MHI_EE_EDL),
198 };
199 
200 /**
201  * enum mhi_er_data_type - Event ring data types
202  * @MHI_ER_DATA: Only client data over this ring
203  * @MHI_ER_CTRL: MHI control data and client data
204  */
205 enum mhi_er_data_type {
206 	MHI_ER_DATA,
207 	MHI_ER_CTRL,
208 };
209 
210 /**
211  * enum mhi_db_brst_mode - Doorbell mode
212  * @MHI_DB_BRST_DISABLE: Burst mode disable
213  * @MHI_DB_BRST_ENABLE: Burst mode enable
214  */
215 enum mhi_db_brst_mode {
216 	MHI_DB_BRST_DISABLE = 0x2,
217 	MHI_DB_BRST_ENABLE = 0x3,
218 };
219 
220 /**
221  * struct mhi_channel_config - Channel configuration structure for controller
222  * @name: The name of this channel
223  * @num: The number assigned to this channel
224  * @num_elements: The number of elements that can be queued to this channel
225  * @local_elements: The local ring length of the channel
226  * @event_ring: The event ring index that services this channel
227  * @dir: Direction that data may flow on this channel
228  * @type: Channel type
229  * @ee_mask: Execution Environment mask for this channel
230  * @pollcfg: Polling configuration for burst mode.  0 is default.  milliseconds
231  *	     for UL channels, multiple of 8 ring elements for DL channels
232  * @doorbell: Doorbell mode
233  * @lpm_notify: The channel master requires low power mode notifications
234  * @offload_channel: The client manages the channel completely
235  * @doorbell_mode_switch: Channel switches to doorbell mode on M0 transition
236  * @wake_capable: Channel capable of waking up the system
237  */
238 struct mhi_channel_config {
239 	char *name;
240 	u32 num;
241 	u32 num_elements;
242 	u32 local_elements;
243 	u32 event_ring;
244 	enum dma_data_direction dir;
245 	enum mhi_ch_type type;
246 	u32 ee_mask;
247 	u32 pollcfg;
248 	enum mhi_db_brst_mode doorbell;
249 	bool lpm_notify;
250 	bool offload_channel;
251 	bool doorbell_mode_switch;
252 	bool wake_capable;
253 };
254 
255 /**
256  * struct mhi_event_config - Event ring configuration structure for controller
257  * @num_elements: The number of elements that can be queued to this ring
258  * @irq_moderation_ms: Delay irq for additional events to be aggregated
259  * @irq: IRQ associated with this ring
260  * @channel: Dedicated channel number. U32_MAX indicates a non-dedicated ring
261  * @priority: Priority of this ring. Use 1 for now
262  * @mode: Doorbell mode
263  * @data_type: Type of data this ring will process
264  * @hardware_event: This ring is associated with hardware channels
265  * @client_managed: This ring is client managed
266  * @offload_channel: This ring is associated with an offloaded channel
267  */
268 struct mhi_event_config {
269 	u32 num_elements;
270 	u32 irq_moderation_ms;
271 	u32 irq;
272 	u32 channel;
273 	u32 priority;
274 	enum mhi_db_brst_mode mode;
275 	enum mhi_er_data_type data_type;
276 	bool hardware_event;
277 	bool client_managed;
278 	bool offload_channel;
279 };
280 
281 /**
282  * struct mhi_controller_config - Root MHI controller configuration
283  * @max_channels: Maximum number of channels supported
284  * @timeout_ms: Timeout value for operations. 0 means use default
285  * @ready_timeout_ms: Timeout value for waiting device to be ready (optional)
286  * @buf_len: Size of automatically allocated buffers. 0 means use default
287  * @num_channels: Number of channels defined in @ch_cfg
288  * @ch_cfg: Array of defined channels
289  * @num_events: Number of event rings defined in @event_cfg
290  * @event_cfg: Array of defined event rings
291  * @use_bounce_buf: Use a bounce buffer pool due to limited DDR access
292  * @m2_no_db: Host is not allowed to ring DB in M2 state
293  */
294 struct mhi_controller_config {
295 	u32 max_channels;
296 	u32 timeout_ms;
297 	u32 ready_timeout_ms;
298 	u32 buf_len;
299 	u32 num_channels;
300 	const struct mhi_channel_config *ch_cfg;
301 	u32 num_events;
302 	struct mhi_event_config *event_cfg;
303 	bool use_bounce_buf;
304 	bool m2_no_db;
305 };
306 
307 /**
308  * struct mhi_controller - Master MHI controller structure
309  * @name: Device name of the MHI controller
310  * @cntrl_dev: Pointer to the struct device of physical bus acting as the MHI
311  *            controller (required)
312  * @mhi_dev: MHI device instance for the controller
313  * @debugfs_dentry: MHI controller debugfs directory
314  * @regs: Base address of MHI MMIO register space (required)
315  * @bhi: Points to base of MHI BHI register space
316  * @bhie: Points to base of MHI BHIe register space
317  * @wake_db: MHI WAKE doorbell register address
318  * @iova_start: IOMMU starting address for data (required)
319  * @iova_stop: IOMMU stop address for data (required)
320  * @fw_image: Firmware image name for normal booting (optional)
321  * @fw_data: Firmware image data content for normal booting, used only
322  *           if fw_image is NULL and fbc_download is true (optional)
323  * @fw_sz: Firmware image data size for normal booting, used only if fw_image
324  *         is NULL and fbc_download is true (optional)
325  * @edl_image: Firmware image name for emergency download mode (optional)
326  * @rddm_size: RAM dump size that host should allocate for debugging purpose
327  * @sbl_size: SBL image size downloaded through BHIe (optional)
328  * @seg_len: BHIe vector size (optional)
329  * @reg_len: Length of the MHI MMIO region (required)
330  * @fbc_image: Points to firmware image buffer
331  * @rddm_image: Points to RAM dump buffer
332  * @mhi_chan: Points to the channel configuration table
333  * @lpm_chans: List of channels that require LPM notifications
334  * @irq: base irq # to request (required)
335  * @max_chan: Maximum number of channels the controller supports
336  * @total_ev_rings: Total # of event rings allocated
337  * @hw_ev_rings: Number of hardware event rings
338  * @sw_ev_rings: Number of software event rings
339  * @nr_irqs: Number of IRQ allocated by bus master (required)
340  * @serial_number: MHI controller serial number obtained from BHI
341  * @mhi_event: MHI event ring configurations table
342  * @mhi_cmd: MHI command ring configurations table
343  * @mhi_ctxt: MHI device context, shared memory between host and device
344  * @pm_mutex: Mutex for suspend/resume operation
345  * @pm_lock: Lock for protecting MHI power management state
346  * @timeout_ms: Timeout in ms for state transitions
347  * @ready_timeout_ms: Timeout in ms for waiting device to be ready (optional)
348  * @pm_state: MHI power management state
349  * @db_access: DB access states
350  * @ee: MHI device execution environment
351  * @dev_state: MHI device state
352  * @dev_wake: Device wakeup count
353  * @pending_pkts: Pending packets for the controller
354  * @M0: Counter to track number of device MHI state changes
355  * @M2: Counter to track number of device MHI state changes
356  * @M3: Counter to track number of device MHI state changes
357  * @transition_list: List of MHI state transitions
358  * @transition_lock: Lock for protecting MHI state transition list
359  * @wlock: Lock for protecting device wakeup
360  * @mhi_link_info: Device bandwidth info
361  * @st_worker: State transition worker
362  * @hiprio_wq: High priority workqueue for MHI work such as state transitions
363  * @state_event: State change event
364  * @status_cb: CB function to notify power states of the device (required)
365  * @wake_get: CB function to assert device wake (optional)
366  * @wake_put: CB function to de-assert device wake (optional)
367  * @wake_toggle: CB function to assert and de-assert device wake (optional)
368  * @runtime_get: CB function to controller runtime resume (required)
369  * @runtime_put: CB function to decrement pm usage (required)
370  * @map_single: CB function to create TRE buffer
371  * @unmap_single: CB function to destroy TRE buffer
372  * @read_reg: Read a MHI register via the physical link (required)
373  * @write_reg: Write a MHI register via the physical link (required)
374  * @reset: Controller specific reset function (optional)
375  * @edl_trigger: CB function to trigger EDL mode (optional)
376  * @buffer_len: Bounce buffer length
377  * @index: Index of the MHI controller instance
378  * @bounce_buf: Use of bounce buffer
379  * @fbc_download: MHI host needs to do complete image transfer (optional)
380  * @wake_set: Device wakeup set flag
381  * @no_m3: Device doesn't support M3 state
382  * @irq_flags: irq flags passed to request_irq (optional)
383  * @mru: the default MRU for the MHI device
384  *
385  * Fields marked as (required) need to be populated by the controller driver
386  * before calling mhi_register_controller(). For the fields marked as (optional)
387  * they can be populated depending on the usecase.
388  */
389 struct mhi_controller {
390 	const char *name;
391 	struct device *cntrl_dev;
392 	struct mhi_device *mhi_dev;
393 	struct dentry *debugfs_dentry;
394 	void __iomem *regs;
395 	void __iomem *bhi;
396 	void __iomem *bhie;
397 	void __iomem *wake_db;
398 
399 	dma_addr_t iova_start;
400 	dma_addr_t iova_stop;
401 	const char *fw_image;
402 	const u8 *fw_data;
403 	size_t fw_sz;
404 	const char *edl_image;
405 	size_t rddm_size;
406 	size_t sbl_size;
407 	size_t seg_len;
408 	size_t reg_len;
409 	struct image_info *fbc_image;
410 	struct image_info *rddm_image;
411 	struct mhi_chan *mhi_chan;
412 	struct list_head lpm_chans;
413 	int *irq;
414 	u32 max_chan;
415 	u32 total_ev_rings;
416 	u32 hw_ev_rings;
417 	u32 sw_ev_rings;
418 	u32 nr_irqs;
419 	u32 serial_number;
420 
421 	struct mhi_event *mhi_event;
422 	struct mhi_cmd *mhi_cmd;
423 	struct mhi_ctxt *mhi_ctxt;
424 
425 	struct mutex pm_mutex;
426 	rwlock_t pm_lock;
427 	u32 timeout_ms;
428 	u32 ready_timeout_ms;
429 	u32 pm_state;
430 	u32 db_access;
431 	enum mhi_ee_type ee;
432 	enum mhi_state dev_state;
433 	atomic_t dev_wake;
434 	atomic_t pending_pkts;
435 	u32 M0, M2, M3;
436 	struct list_head transition_list;
437 	spinlock_t transition_lock;
438 	spinlock_t wlock;
439 	struct mhi_link_info mhi_link_info;
440 	struct work_struct st_worker;
441 	struct workqueue_struct *hiprio_wq;
442 	wait_queue_head_t state_event;
443 
444 	void (*status_cb)(struct mhi_controller *mhi_cntrl,
445 			  enum mhi_callback cb);
446 	void (*wake_get)(struct mhi_controller *mhi_cntrl, bool override);
447 	void (*wake_put)(struct mhi_controller *mhi_cntrl, bool override);
448 	void (*wake_toggle)(struct mhi_controller *mhi_cntrl);
449 	int (*runtime_get)(struct mhi_controller *mhi_cntrl);
450 	void (*runtime_put)(struct mhi_controller *mhi_cntrl);
451 	int (*map_single)(struct mhi_controller *mhi_cntrl,
452 			  struct mhi_buf_info *buf);
453 	void (*unmap_single)(struct mhi_controller *mhi_cntrl,
454 			     struct mhi_buf_info *buf);
455 	int (*read_reg)(struct mhi_controller *mhi_cntrl, void __iomem *addr,
456 			u32 *out);
457 	void (*write_reg)(struct mhi_controller *mhi_cntrl, void __iomem *addr,
458 			  u32 val);
459 	void (*reset)(struct mhi_controller *mhi_cntrl);
460 	int (*edl_trigger)(struct mhi_controller *mhi_cntrl);
461 
462 	size_t buffer_len;
463 	int index;
464 	bool bounce_buf;
465 	bool fbc_download;
466 	bool wake_set;
467 	bool no_m3;
468 	unsigned long irq_flags;
469 	u32 mru;
470 };
471 
472 /**
473  * struct mhi_device - Structure representing an MHI device which binds
474  *                     to channels or is associated with controllers
475  * @id: Pointer to MHI device ID struct
476  * @name: Name of the associated MHI device
477  * @mhi_cntrl: Controller the device belongs to
478  * @ul_chan: UL channel for the device
479  * @dl_chan: DL channel for the device
480  * @dev: Driver model device node for the MHI device
481  * @dev_type: MHI device type
482  * @ul_chan_id: MHI channel id for UL transfer
483  * @dl_chan_id: MHI channel id for DL transfer
484  * @dev_wake: Device wakeup counter
485  */
486 struct mhi_device {
487 	const struct mhi_device_id *id;
488 	const char *name;
489 	struct mhi_controller *mhi_cntrl;
490 	struct mhi_chan *ul_chan;
491 	struct mhi_chan *dl_chan;
492 	struct device dev;
493 	enum mhi_device_type dev_type;
494 	int ul_chan_id;
495 	int dl_chan_id;
496 	u32 dev_wake;
497 };
498 
499 /**
500  * struct mhi_result - Completed buffer information
501  * @buf_addr: Address of data buffer
502  * @bytes_xferd: # of bytes transferred
503  * @dir: Channel direction
504  * @transaction_status: Status of last transaction
505  */
506 struct mhi_result {
507 	void *buf_addr;
508 	size_t bytes_xferd;
509 	enum dma_data_direction dir;
510 	int transaction_status;
511 };
512 
513 /**
514  * struct mhi_driver - Structure representing a MHI client driver
515  * @id_table: table of MHI channel names that a driver supports
516  * @probe: CB function for client driver probe function
517  * @remove: CB function for client driver remove function
518  * @ul_xfer_cb: CB function for UL data transfer
519  * @dl_xfer_cb: CB function for DL data transfer
520  * @status_cb: CB functions for asynchronous status
521  * @driver: Device driver model driver
522  */
523 struct mhi_driver {
524 	const struct mhi_device_id *id_table;
525 	int (*probe)(struct mhi_device *mhi_dev,
526 		     const struct mhi_device_id *id);
527 	void (*remove)(struct mhi_device *mhi_dev);
528 	void (*ul_xfer_cb)(struct mhi_device *mhi_dev,
529 			   struct mhi_result *result);
530 	void (*dl_xfer_cb)(struct mhi_device *mhi_dev,
531 			   struct mhi_result *result);
532 	void (*status_cb)(struct mhi_device *mhi_dev, enum mhi_callback mhi_cb);
533 	struct device_driver driver;
534 };
535 
536 #define to_mhi_driver(drv) container_of_const(drv, struct mhi_driver, driver)
537 #define to_mhi_device(dev) container_of(dev, struct mhi_device, dev)
538 
539 /**
540  * mhi_alloc_controller - Allocate the MHI Controller structure
541  * Allocate the mhi_controller structure using zero initialized memory
542  */
543 struct mhi_controller *mhi_alloc_controller(void);
544 
545 /**
546  * mhi_free_controller - Free the MHI Controller structure
547  * @mhi_cntrl: MHI controller to free
548  * Free the mhi_controller structure which was previously allocated
549  */
550 void mhi_free_controller(struct mhi_controller *mhi_cntrl);
551 
552 /**
553  * mhi_register_controller - Register MHI controller
554  * @mhi_cntrl: MHI controller to register
555  * @config: Configuration to use for the controller
556  */
557 int mhi_register_controller(struct mhi_controller *mhi_cntrl,
558 			const struct mhi_controller_config *config);
559 
560 /**
561  * mhi_unregister_controller - Unregister MHI controller
562  * @mhi_cntrl: MHI controller to unregister
563  */
564 void mhi_unregister_controller(struct mhi_controller *mhi_cntrl);
565 
566 /*
567  * module_mhi_driver() - Helper macro for drivers that don't do
568  * anything special other than using default mhi_driver_register() and
569  * mhi_driver_unregister().  This eliminates a lot of boilerplate.
570  * Each module may only use this macro once.
571  */
572 #define module_mhi_driver(mhi_drv) \
573 	module_driver(mhi_drv, mhi_driver_register, \
574 		      mhi_driver_unregister)
575 
576 /*
577  * Macro to avoid include chaining to get THIS_MODULE
578  */
579 #define mhi_driver_register(mhi_drv) \
580 	__mhi_driver_register(mhi_drv, THIS_MODULE)
581 
582 /**
583  * __mhi_driver_register - Register driver with MHI framework
584  * @mhi_drv: Driver associated with the device
585  * @owner: The module owner
586  */
587 int __mhi_driver_register(struct mhi_driver *mhi_drv, struct module *owner);
588 
589 /**
590  * mhi_driver_unregister - Unregister a driver for mhi_devices
591  * @mhi_drv: Driver associated with the device
592  */
593 void mhi_driver_unregister(struct mhi_driver *mhi_drv);
594 
595 /**
596  * mhi_set_mhi_state - Set MHI device state
597  * @mhi_cntrl: MHI controller
598  * @state: State to set
599  */
600 void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl,
601 		       enum mhi_state state);
602 
603 /**
604  * mhi_notify - Notify the MHI client driver about client device status
605  * @mhi_dev: MHI device instance
606  * @cb_reason: MHI callback reason
607  */
608 void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason);
609 
610 /**
611  * mhi_get_free_desc_count - Get transfer ring length
612  * Get # of TD available to queue buffers
613  * @mhi_dev: Device associated with the channels
614  * @dir: Direction of the channel
615  */
616 int mhi_get_free_desc_count(struct mhi_device *mhi_dev,
617 				enum dma_data_direction dir);
618 
619 /**
620  * mhi_prepare_for_power_up - Do pre-initialization before power up.
621  *                            This is optional, call this before power up if
622  *                            the controller does not want bus framework to
623  *                            automatically free any allocated memory during
624  *                            shutdown process.
625  * @mhi_cntrl: MHI controller
626  */
627 int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl);
628 
629 /**
630  * mhi_async_power_up - Start MHI power up sequence
631  * @mhi_cntrl: MHI controller
632  */
633 int mhi_async_power_up(struct mhi_controller *mhi_cntrl);
634 
635 /**
636  * mhi_sync_power_up - Start MHI power up sequence and wait till the device
637  *                     enters valid EE state
638  * @mhi_cntrl: MHI controller
639  */
640 int mhi_sync_power_up(struct mhi_controller *mhi_cntrl);
641 
642 /**
643  * mhi_power_down - Power down the MHI device and also destroy the
644  *                  'struct device' for the channels associated with it.
645  *                  See also mhi_power_down_keep_dev() which is a variant
646  *                  of this API that keeps the 'struct device' for channels
647  *                  (useful during suspend/hibernation).
648  * @mhi_cntrl: MHI controller
649  * @graceful: Link is still accessible, so do a graceful shutdown process
650  */
651 void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful);
652 
653 /**
654  * mhi_power_down_keep_dev - Power down the MHI device but keep the 'struct
655  *                           device' for the channels associated with it.
656  *                           This is a variant of 'mhi_power_down()' and
657  *                           useful in scenarios such as suspend/hibernation
658  *                           where destroying of the 'struct device' is not
659  *                           needed.
660  * @mhi_cntrl: MHI controller
661  * @graceful: Link is still accessible, so do a graceful shutdown process
662  */
663 void mhi_power_down_keep_dev(struct mhi_controller *mhi_cntrl, bool graceful);
664 
665 /**
666  * mhi_unprepare_after_power_down - Free any allocated memory after power down
667  * @mhi_cntrl: MHI controller
668  */
669 void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl);
670 
671 /**
672  * mhi_pm_suspend - Move MHI into a suspended state
673  * @mhi_cntrl: MHI controller
674  */
675 int mhi_pm_suspend(struct mhi_controller *mhi_cntrl);
676 
677 /**
678  * mhi_pm_resume - Resume MHI from suspended state
679  * @mhi_cntrl: MHI controller
680  */
681 int mhi_pm_resume(struct mhi_controller *mhi_cntrl);
682 
683 /**
684  * mhi_pm_resume_force - Force resume MHI from suspended state
685  * @mhi_cntrl: MHI controller
686  *
687  * Resume the device irrespective of its MHI state. As per the MHI spec, devices
688  * has to be in M3 state during resume. But some devices seem to be in a
689  * different MHI state other than M3 but they continue working fine if allowed.
690  * This API is intented to be used for such devices.
691  *
692  * Return: 0 if the resume succeeds, a negative error code otherwise
693  */
694 int mhi_pm_resume_force(struct mhi_controller *mhi_cntrl);
695 
696 /**
697  * mhi_download_rddm_image - Download ramdump image from device for
698  *                           debugging purpose.
699  * @mhi_cntrl: MHI controller
700  * @in_panic: Download rddm image during kernel panic
701  */
702 int mhi_download_rddm_image(struct mhi_controller *mhi_cntrl, bool in_panic);
703 
704 /**
705  * mhi_force_rddm_mode - Force device into rddm mode
706  * @mhi_cntrl: MHI controller
707  */
708 int mhi_force_rddm_mode(struct mhi_controller *mhi_cntrl);
709 
710 /**
711  * mhi_get_exec_env - Get BHI execution environment of the device
712  * @mhi_cntrl: MHI controller
713  */
714 enum mhi_ee_type mhi_get_exec_env(struct mhi_controller *mhi_cntrl);
715 
716 /**
717  * mhi_get_mhi_state - Get MHI state of the device
718  * @mhi_cntrl: MHI controller
719  */
720 enum mhi_state mhi_get_mhi_state(struct mhi_controller *mhi_cntrl);
721 
722 /**
723  * mhi_soc_reset - Trigger a device reset. This can be used as a last resort
724  *		   to reset and recover a device.
725  * @mhi_cntrl: MHI controller
726  */
727 void mhi_soc_reset(struct mhi_controller *mhi_cntrl);
728 
729 /**
730  * mhi_device_get_sync - Disable device low power mode. Synchronously
731  *                       take the controller out of suspended state
732  * @mhi_dev: Device associated with the channel
733  */
734 int mhi_device_get_sync(struct mhi_device *mhi_dev);
735 
736 /**
737  * mhi_device_put - Re-enable device low power mode
738  * @mhi_dev: Device associated with the channel
739  */
740 void mhi_device_put(struct mhi_device *mhi_dev);
741 
742 /**
743  * mhi_prepare_for_transfer - Setup UL and DL channels for data transfer.
744  * @mhi_dev: Device associated with the channels
745  *
746  * Allocate and initialize the channel context and also issue the START channel
747  * command to both channels. Channels can be started only if both host and
748  * device execution environments match and channels are in a DISABLED state.
749  */
750 int mhi_prepare_for_transfer(struct mhi_device *mhi_dev);
751 
752 /**
753  * mhi_unprepare_from_transfer - Reset UL and DL channels for data transfer.
754  *                               Issue the RESET channel command and let the
755  *                               device clean-up the context so no incoming
756  *                               transfers are seen on the host. Free memory
757  *                               associated with the context on host. If device
758  *                               is unresponsive, only perform a host side
759  *                               clean-up. Channels can be reset only if both
760  *                               host and device execution environments match
761  *                               and channels are in an ENABLED, STOPPED or
762  *                               SUSPENDED state.
763  * @mhi_dev: Device associated with the channels
764  */
765 void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev);
766 
767 /**
768  * mhi_queue_buf - Send or receive raw buffers from client device over MHI
769  *                 channel
770  * @mhi_dev: Device associated with the channels
771  * @dir: DMA direction for the channel
772  * @buf: Buffer for holding the data
773  * @len: Buffer length
774  * @mflags: MHI transfer flags used for the transfer
775  */
776 int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir,
777 		  void *buf, size_t len, enum mhi_flags mflags);
778 
779 /**
780  * mhi_queue_skb - Send or receive SKBs from client device over MHI channel
781  * @mhi_dev: Device associated with the channels
782  * @dir: DMA direction for the channel
783  * @skb: Buffer for holding SKBs
784  * @len: Buffer length
785  * @mflags: MHI transfer flags used for the transfer
786  */
787 int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir,
788 		  struct sk_buff *skb, size_t len, enum mhi_flags mflags);
789 
790 /**
791  * mhi_queue_is_full - Determine whether queueing new elements is possible
792  * @mhi_dev: Device associated with the channels
793  * @dir: DMA direction for the channel
794  */
795 bool mhi_queue_is_full(struct mhi_device *mhi_dev, enum dma_data_direction dir);
796 
797 /**
798  * mhi_get_channel_doorbell_offset - Get the channel doorbell offset
799  * @mhi_cntrl: MHI controller
800  * @chdb_offset: Read channel doorbell offset
801  *
802  * Return: 0 if the read succeeds, a negative error code otherwise
803  */
804 int mhi_get_channel_doorbell_offset(struct mhi_controller *mhi_cntrl, u32 *chdb_offset);
805 
806 #endif /* _MHI_H_ */
807