1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (c) 2022, Linaro Ltd.
4 *
5 */
6#ifndef _MHI_EP_H_
7#define _MHI_EP_H_
8
9#include <linux/dma-direction.h>
10#include <linux/mhi.h>
11
12#define MHI_EP_DEFAULT_MTU 0x8000
13
14/**
15 * struct mhi_ep_channel_config - Channel configuration structure for controller
16 * @name: The name of this channel
17 * @num: The number assigned to this channel
18 * @num_elements: The number of elements that can be queued to this channel
19 * @dir: Direction that data may flow on this channel
20 */
21struct mhi_ep_channel_config {
22 char *name;
23 u32 num;
24 u32 num_elements;
25 enum dma_data_direction dir;
26};
27
28/**
29 * struct mhi_ep_cntrl_config - MHI Endpoint controller configuration
30 * @mhi_version: MHI spec version supported by the controller
31 * @max_channels: Maximum number of channels supported
32 * @num_channels: Number of channels defined in @ch_cfg
33 * @ch_cfg: Array of defined channels
34 */
35struct mhi_ep_cntrl_config {
36 u32 mhi_version;
37 u32 max_channels;
38 u32 num_channels;
39 const struct mhi_ep_channel_config *ch_cfg;
40};
41
42/**
43 * struct mhi_ep_db_info - MHI Endpoint doorbell info
44 * @mask: Mask of the doorbell interrupt
45 * @status: Status of the doorbell interrupt
46 */
47struct mhi_ep_db_info {
48 u32 mask;
49 u32 status;
50};
51
52/**
53 * struct mhi_ep_cntrl - MHI Endpoint controller structure
54 * @cntrl_dev: Pointer to the struct device of physical bus acting as the MHI
55 * Endpoint controller
56 * @mhi_dev: MHI Endpoint device instance for the controller
57 * @mmio: MMIO region containing the MHI registers
58 * @mhi_chan: Points to the channel configuration table
59 * @mhi_event: Points to the event ring configurations table
60 * @mhi_cmd: Points to the command ring configurations table
61 * @sm: MHI Endpoint state machine
62 * @ch_ctx_cache: Cache of host channel context data structure
63 * @ev_ctx_cache: Cache of host event context data structure
64 * @cmd_ctx_cache: Cache of host command context data structure
65 * @ch_ctx_host_pa: Physical address of host channel context data structure
66 * @ev_ctx_host_pa: Physical address of host event context data structure
67 * @cmd_ctx_host_pa: Physical address of host command context data structure
68 * @ch_ctx_cache_phys: Physical address of the host channel context cache
69 * @ev_ctx_cache_phys: Physical address of the host event context cache
70 * @cmd_ctx_cache_phys: Physical address of the host command context cache
71 * @chdb: Array of channel doorbell interrupt info
72 * @event_lock: Lock for protecting event rings
73 * @state_lock: Lock for protecting state transitions
74 * @list_lock: Lock for protecting state transition and channel doorbell lists
75 * @st_transition_list: List of state transitions
76 * @ch_db_list: List of queued channel doorbells
77 * @wq: Dedicated workqueue for handling rings and state changes
78 * @state_work: State transition worker
79 * @reset_work: Worker for MHI Endpoint reset
80 * @cmd_ring_work: Worker for processing command rings
81 * @ch_ring_work: Worker for processing channel rings
82 * @raise_irq: CB function for raising IRQ to the host
83 * @alloc_map: CB function for allocating memory in endpoint for storing host context and mapping it
84 * @unmap_free: CB function to unmap and free the allocated memory in endpoint for storing host context
85 * @read_from_host: CB function for reading from host memory from endpoint
86 * @write_to_host: CB function for writing to host memory from endpoint
87 * @mhi_state: MHI Endpoint state
88 * @max_chan: Maximum channels supported by the endpoint controller
89 * @mru: MRU (Maximum Receive Unit) value of the endpoint controller
90 * @event_rings: Number of event rings supported by the endpoint controller
91 * @hw_event_rings: Number of hardware event rings supported by the endpoint controller
92 * @chdb_offset: Channel doorbell offset set by the host
93 * @erdb_offset: Event ring doorbell offset set by the host
94 * @index: MHI Endpoint controller index
95 * @irq: IRQ used by the endpoint controller
96 * @enabled: Check if the endpoint controller is enabled or not
97 */
98struct mhi_ep_cntrl {
99 struct device *cntrl_dev;
100 struct mhi_ep_device *mhi_dev;
101 void __iomem *mmio;
102
103 struct mhi_ep_chan *mhi_chan;
104 struct mhi_ep_event *mhi_event;
105 struct mhi_ep_cmd *mhi_cmd;
106 struct mhi_ep_sm *sm;
107
108 struct mhi_chan_ctxt *ch_ctx_cache;
109 struct mhi_event_ctxt *ev_ctx_cache;
110 struct mhi_cmd_ctxt *cmd_ctx_cache;
111 u64 ch_ctx_host_pa;
112 u64 ev_ctx_host_pa;
113 u64 cmd_ctx_host_pa;
114 phys_addr_t ch_ctx_cache_phys;
115 phys_addr_t ev_ctx_cache_phys;
116 phys_addr_t cmd_ctx_cache_phys;
117
118 struct mhi_ep_db_info chdb[4];
119 struct mutex event_lock;
120 struct mutex state_lock;
121 spinlock_t list_lock;
122
123 struct list_head st_transition_list;
124 struct list_head ch_db_list;
125
126 struct workqueue_struct *wq;
127 struct work_struct state_work;
128 struct work_struct reset_work;
129 struct work_struct cmd_ring_work;
130 struct work_struct ch_ring_work;
131
132 void (*raise_irq)(struct mhi_ep_cntrl *mhi_cntrl, u32 vector);
133 int (*alloc_map)(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr, phys_addr_t *phys_ptr,
134 void __iomem **virt, size_t size);
135 void (*unmap_free)(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr, phys_addr_t phys,
136 void __iomem *virt, size_t size);
137 int (*read_from_host)(struct mhi_ep_cntrl *mhi_cntrl, u64 from, void *to, size_t size);
138 int (*write_to_host)(struct mhi_ep_cntrl *mhi_cntrl, void *from, u64 to, size_t size);
139
140 enum mhi_state mhi_state;
141
142 u32 max_chan;
143 u32 mru;
144 u32 event_rings;
145 u32 hw_event_rings;
146 u32 chdb_offset;
147 u32 erdb_offset;
148 u32 index;
149 int irq;
150 bool enabled;
151};
152
153/**
154 * struct mhi_ep_device - Structure representing an MHI Endpoint device that binds
155 * to channels or is associated with controllers
156 * @dev: Driver model device node for the MHI Endpoint device
157 * @mhi_cntrl: Controller the device belongs to
158 * @id: Pointer to MHI Endpoint device ID struct
159 * @name: Name of the associated MHI Endpoint device
160 * @ul_chan: UL (from host to endpoint) channel for the device
161 * @dl_chan: DL (from endpoint to host) channel for the device
162 * @dev_type: MHI device type
163 */
164struct mhi_ep_device {
165 struct device dev;
166 struct mhi_ep_cntrl *mhi_cntrl;
167 const struct mhi_device_id *id;
168 const char *name;
169 struct mhi_ep_chan *ul_chan;
170 struct mhi_ep_chan *dl_chan;
171 enum mhi_device_type dev_type;
172};
173
174/**
175 * struct mhi_ep_driver - Structure representing a MHI Endpoint client driver
176 * @id_table: Pointer to MHI Endpoint device ID table
177 * @driver: Device driver model driver
178 * @probe: CB function for client driver probe function
179 * @remove: CB function for client driver remove function
180 * @ul_xfer_cb: CB function for UL (from host to endpoint) data transfer
181 * @dl_xfer_cb: CB function for DL (from endpoint to host) data transfer
182 */
183struct mhi_ep_driver {
184 const struct mhi_device_id *id_table;
185 struct device_driver driver;
186 int (*probe)(struct mhi_ep_device *mhi_ep,
187 const struct mhi_device_id *id);
188 void (*remove)(struct mhi_ep_device *mhi_ep);
189 void (*ul_xfer_cb)(struct mhi_ep_device *mhi_dev,
190 struct mhi_result *result);
191 void (*dl_xfer_cb)(struct mhi_ep_device *mhi_dev,
192 struct mhi_result *result);
193};
194
195#define to_mhi_ep_device(dev) container_of(dev, struct mhi_ep_device, dev)
196#define to_mhi_ep_driver(drv) container_of(drv, struct mhi_ep_driver, driver)
197
198/*
199 * module_mhi_ep_driver() - Helper macro for drivers that don't do
200 * anything special other than using default mhi_ep_driver_register() and
201 * mhi_ep_driver_unregister(). This eliminates a lot of boilerplate.
202 * Each module may only use this macro once.
203 */
204#define module_mhi_ep_driver(mhi_drv) \
205 module_driver(mhi_drv, mhi_ep_driver_register, \
206 mhi_ep_driver_unregister)
207
208/*
209 * Macro to avoid include chaining to get THIS_MODULE
210 */
211#define mhi_ep_driver_register(mhi_drv) \
212 __mhi_ep_driver_register(mhi_drv, THIS_MODULE)
213
214/**
215 * __mhi_ep_driver_register - Register a driver with MHI Endpoint bus
216 * @mhi_drv: Driver to be associated with the device
217 * @owner: The module owner
218 *
219 * Return: 0 if driver registrations succeeds, a negative error code otherwise.
220 */
221int __mhi_ep_driver_register(struct mhi_ep_driver *mhi_drv, struct module *owner);
222
223/**
224 * mhi_ep_driver_unregister - Unregister a driver from MHI Endpoint bus
225 * @mhi_drv: Driver associated with the device
226 */
227void mhi_ep_driver_unregister(struct mhi_ep_driver *mhi_drv);
228
229/**
230 * mhi_ep_register_controller - Register MHI Endpoint controller
231 * @mhi_cntrl: MHI Endpoint controller to register
232 * @config: Configuration to use for the controller
233 *
234 * Return: 0 if controller registrations succeeds, a negative error code otherwise.
235 */
236int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl,
237 const struct mhi_ep_cntrl_config *config);
238
239/**
240 * mhi_ep_unregister_controller - Unregister MHI Endpoint controller
241 * @mhi_cntrl: MHI Endpoint controller to unregister
242 */
243void mhi_ep_unregister_controller(struct mhi_ep_cntrl *mhi_cntrl);
244
245/**
246 * mhi_ep_power_up - Power up the MHI endpoint stack
247 * @mhi_cntrl: MHI Endpoint controller
248 *
249 * Return: 0 if power up succeeds, a negative error code otherwise.
250 */
251int mhi_ep_power_up(struct mhi_ep_cntrl *mhi_cntrl);
252
253/**
254 * mhi_ep_power_down - Power down the MHI endpoint stack
255 * @mhi_cntrl: MHI controller
256 */
257void mhi_ep_power_down(struct mhi_ep_cntrl *mhi_cntrl);
258
259/**
260 * mhi_ep_queue_is_empty - Determine whether the transfer queue is empty
261 * @mhi_dev: Device associated with the channels
262 * @dir: DMA direction for the channel
263 *
264 * Return: true if the queue is empty, false otherwise.
265 */
266bool mhi_ep_queue_is_empty(struct mhi_ep_device *mhi_dev, enum dma_data_direction dir);
267
268/**
269 * mhi_ep_queue_skb - Send SKBs to host over MHI Endpoint
270 * @mhi_dev: Device associated with the DL channel
271 * @skb: SKBs to be queued
272 *
273 * Return: 0 if the SKBs has been sent successfully, a negative error code otherwise.
274 */
275int mhi_ep_queue_skb(struct mhi_ep_device *mhi_dev, struct sk_buff *skb);
276
277#endif
278

source code of linux/include/linux/mhi_ep.h