xref: /openbmc/linux/include/linux/mhi_ep.h (revision 2984f26a)
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  */
21 struct 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  */
35 struct 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  */
47 struct mhi_ep_db_info {
48 	u32 mask;
49 	u32 status;
50 };
51 
52 /**
53  * struct mhi_ep_buf_info - MHI Endpoint transfer buffer info
54  * @dev_addr: Address of the buffer in endpoint
55  * @host_addr: Address of the bufffer in host
56  * @size: Size of the buffer
57  */
58 struct mhi_ep_buf_info {
59 	void *dev_addr;
60 	u64 host_addr;
61 	size_t size;
62 };
63 
64 /**
65  * struct mhi_ep_cntrl - MHI Endpoint controller structure
66  * @cntrl_dev: Pointer to the struct device of physical bus acting as the MHI
67  *             Endpoint controller
68  * @mhi_dev: MHI Endpoint device instance for the controller
69  * @mmio: MMIO region containing the MHI registers
70  * @mhi_chan: Points to the channel configuration table
71  * @mhi_event: Points to the event ring configurations table
72  * @mhi_cmd: Points to the command ring configurations table
73  * @sm: MHI Endpoint state machine
74  * @ch_ctx_cache: Cache of host channel context data structure
75  * @ev_ctx_cache: Cache of host event context data structure
76  * @cmd_ctx_cache: Cache of host command context data structure
77  * @ch_ctx_host_pa: Physical address of host channel context data structure
78  * @ev_ctx_host_pa: Physical address of host event context data structure
79  * @cmd_ctx_host_pa: Physical address of host command context data structure
80  * @ch_ctx_cache_phys: Physical address of the host channel context cache
81  * @ev_ctx_cache_phys: Physical address of the host event context cache
82  * @cmd_ctx_cache_phys: Physical address of the host command context cache
83  * @chdb: Array of channel doorbell interrupt info
84  * @event_lock: Lock for protecting event rings
85  * @state_lock: Lock for protecting state transitions
86  * @list_lock: Lock for protecting state transition and channel doorbell lists
87  * @st_transition_list: List of state transitions
88  * @ch_db_list: List of queued channel doorbells
89  * @wq: Dedicated workqueue for handling rings and state changes
90  * @state_work: State transition worker
91  * @reset_work: Worker for MHI Endpoint reset
92  * @cmd_ring_work: Worker for processing command rings
93  * @ch_ring_work: Worker for processing channel rings
94  * @raise_irq: CB function for raising IRQ to the host
95  * @alloc_map: CB function for allocating memory in endpoint for storing host context and mapping it
96  * @unmap_free: CB function to unmap and free the allocated memory in endpoint for storing host context
97  * @read_from_host: CB function for reading from host memory from endpoint
98  * @write_to_host: CB function for writing to host memory from endpoint
99  * @mhi_state: MHI Endpoint state
100  * @max_chan: Maximum channels supported by the endpoint controller
101  * @mru: MRU (Maximum Receive Unit) value of the endpoint controller
102  * @event_rings: Number of event rings supported by the endpoint controller
103  * @hw_event_rings: Number of hardware event rings supported by the endpoint controller
104  * @chdb_offset: Channel doorbell offset set by the host
105  * @erdb_offset: Event ring doorbell offset set by the host
106  * @index: MHI Endpoint controller index
107  * @irq: IRQ used by the endpoint controller
108  * @enabled: Check if the endpoint controller is enabled or not
109  */
110 struct mhi_ep_cntrl {
111 	struct device *cntrl_dev;
112 	struct mhi_ep_device *mhi_dev;
113 	void __iomem *mmio;
114 
115 	struct mhi_ep_chan *mhi_chan;
116 	struct mhi_ep_event *mhi_event;
117 	struct mhi_ep_cmd *mhi_cmd;
118 	struct mhi_ep_sm *sm;
119 
120 	struct mhi_chan_ctxt *ch_ctx_cache;
121 	struct mhi_event_ctxt *ev_ctx_cache;
122 	struct mhi_cmd_ctxt *cmd_ctx_cache;
123 	u64 ch_ctx_host_pa;
124 	u64 ev_ctx_host_pa;
125 	u64 cmd_ctx_host_pa;
126 	phys_addr_t ch_ctx_cache_phys;
127 	phys_addr_t ev_ctx_cache_phys;
128 	phys_addr_t cmd_ctx_cache_phys;
129 
130 	struct mhi_ep_db_info chdb[4];
131 	struct mutex event_lock;
132 	struct mutex state_lock;
133 	spinlock_t list_lock;
134 
135 	struct list_head st_transition_list;
136 	struct list_head ch_db_list;
137 
138 	struct workqueue_struct *wq;
139 	struct work_struct state_work;
140 	struct work_struct reset_work;
141 	struct work_struct cmd_ring_work;
142 	struct work_struct ch_ring_work;
143 	struct kmem_cache *ring_item_cache;
144 	struct kmem_cache *ev_ring_el_cache;
145 	struct kmem_cache *tre_buf_cache;
146 
147 	void (*raise_irq)(struct mhi_ep_cntrl *mhi_cntrl, u32 vector);
148 	int (*alloc_map)(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr, phys_addr_t *phys_ptr,
149 			 void __iomem **virt, size_t size);
150 	void (*unmap_free)(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr, phys_addr_t phys,
151 			   void __iomem *virt, size_t size);
152 	int (*read_from_host)(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_buf_info *buf_info);
153 	int (*write_to_host)(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_buf_info *buf_info);
154 
155 	enum mhi_state mhi_state;
156 
157 	u32 max_chan;
158 	u32 mru;
159 	u32 event_rings;
160 	u32 hw_event_rings;
161 	u32 chdb_offset;
162 	u32 erdb_offset;
163 	u32 index;
164 	int irq;
165 	bool enabled;
166 };
167 
168 /**
169  * struct mhi_ep_device - Structure representing an MHI Endpoint device that binds
170  *                     to channels or is associated with controllers
171  * @dev: Driver model device node for the MHI Endpoint device
172  * @mhi_cntrl: Controller the device belongs to
173  * @id: Pointer to MHI Endpoint device ID struct
174  * @name: Name of the associated MHI Endpoint device
175  * @ul_chan: UL (from host to endpoint) channel for the device
176  * @dl_chan: DL (from endpoint to host) channel for the device
177  * @dev_type: MHI device type
178  */
179 struct mhi_ep_device {
180 	struct device dev;
181 	struct mhi_ep_cntrl *mhi_cntrl;
182 	const struct mhi_device_id *id;
183 	const char *name;
184 	struct mhi_ep_chan *ul_chan;
185 	struct mhi_ep_chan *dl_chan;
186 	enum mhi_device_type dev_type;
187 };
188 
189 /**
190  * struct mhi_ep_driver - Structure representing a MHI Endpoint client driver
191  * @id_table: Pointer to MHI Endpoint device ID table
192  * @driver: Device driver model driver
193  * @probe: CB function for client driver probe function
194  * @remove: CB function for client driver remove function
195  * @ul_xfer_cb: CB function for UL (from host to endpoint) data transfer
196  * @dl_xfer_cb: CB function for DL (from endpoint to host) data transfer
197  */
198 struct mhi_ep_driver {
199 	const struct mhi_device_id *id_table;
200 	struct device_driver driver;
201 	int (*probe)(struct mhi_ep_device *mhi_ep,
202 		     const struct mhi_device_id *id);
203 	void (*remove)(struct mhi_ep_device *mhi_ep);
204 	void (*ul_xfer_cb)(struct mhi_ep_device *mhi_dev,
205 			   struct mhi_result *result);
206 	void (*dl_xfer_cb)(struct mhi_ep_device *mhi_dev,
207 			   struct mhi_result *result);
208 };
209 
210 #define to_mhi_ep_device(dev) container_of(dev, struct mhi_ep_device, dev)
211 #define to_mhi_ep_driver(drv) container_of(drv, struct mhi_ep_driver, driver)
212 
213 /*
214  * module_mhi_ep_driver() - Helper macro for drivers that don't do
215  * anything special other than using default mhi_ep_driver_register() and
216  * mhi_ep_driver_unregister().  This eliminates a lot of boilerplate.
217  * Each module may only use this macro once.
218  */
219 #define module_mhi_ep_driver(mhi_drv) \
220 	module_driver(mhi_drv, mhi_ep_driver_register, \
221 		      mhi_ep_driver_unregister)
222 
223 /*
224  * Macro to avoid include chaining to get THIS_MODULE
225  */
226 #define mhi_ep_driver_register(mhi_drv) \
227 	__mhi_ep_driver_register(mhi_drv, THIS_MODULE)
228 
229 /**
230  * __mhi_ep_driver_register - Register a driver with MHI Endpoint bus
231  * @mhi_drv: Driver to be associated with the device
232  * @owner: The module owner
233  *
234  * Return: 0 if driver registrations succeeds, a negative error code otherwise.
235  */
236 int __mhi_ep_driver_register(struct mhi_ep_driver *mhi_drv, struct module *owner);
237 
238 /**
239  * mhi_ep_driver_unregister - Unregister a driver from MHI Endpoint bus
240  * @mhi_drv: Driver associated with the device
241  */
242 void mhi_ep_driver_unregister(struct mhi_ep_driver *mhi_drv);
243 
244 /**
245  * mhi_ep_register_controller - Register MHI Endpoint controller
246  * @mhi_cntrl: MHI Endpoint controller to register
247  * @config: Configuration to use for the controller
248  *
249  * Return: 0 if controller registrations succeeds, a negative error code otherwise.
250  */
251 int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl,
252 			       const struct mhi_ep_cntrl_config *config);
253 
254 /**
255  * mhi_ep_unregister_controller - Unregister MHI Endpoint controller
256  * @mhi_cntrl: MHI Endpoint controller to unregister
257  */
258 void mhi_ep_unregister_controller(struct mhi_ep_cntrl *mhi_cntrl);
259 
260 /**
261  * mhi_ep_power_up - Power up the MHI endpoint stack
262  * @mhi_cntrl: MHI Endpoint controller
263  *
264  * Return: 0 if power up succeeds, a negative error code otherwise.
265  */
266 int mhi_ep_power_up(struct mhi_ep_cntrl *mhi_cntrl);
267 
268 /**
269  * mhi_ep_power_down - Power down the MHI endpoint stack
270  * @mhi_cntrl: MHI controller
271  */
272 void mhi_ep_power_down(struct mhi_ep_cntrl *mhi_cntrl);
273 
274 /**
275  * mhi_ep_queue_is_empty - Determine whether the transfer queue is empty
276  * @mhi_dev: Device associated with the channels
277  * @dir: DMA direction for the channel
278  *
279  * Return: true if the queue is empty, false otherwise.
280  */
281 bool mhi_ep_queue_is_empty(struct mhi_ep_device *mhi_dev, enum dma_data_direction dir);
282 
283 /**
284  * mhi_ep_queue_skb - Send SKBs to host over MHI Endpoint
285  * @mhi_dev: Device associated with the DL channel
286  * @skb: SKBs to be queued
287  *
288  * Return: 0 if the SKBs has been sent successfully, a negative error code otherwise.
289  */
290 int mhi_ep_queue_skb(struct mhi_ep_device *mhi_dev, struct sk_buff *skb);
291 
292 #endif
293