include/linux/mhi_ep.h

   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  * @mhi_dev: MHI device associated with this buffer
  55  * @dev_addr: Address of the buffer in endpoint
  56  * @host_addr: Address of the bufffer in host
  57  * @size: Size of the buffer
  58  * @code: Transfer completion code
  59  * @cb: Callback to be executed by controller drivers after transfer completion (async)
  60  * @cb_buf: Opaque buffer to be passed to the callback
  61  */
  62 struct mhi_ep_buf_info {
  63         struct mhi_ep_device *mhi_dev;
  64         void *dev_addr;
  65         u64 host_addr;
  66         size_t size;
  67         int code;
  68
  69         void (*cb)(struct mhi_ep_buf_info *buf_info);
  70         void *cb_buf;
  71 };
  72
  73 /**
  74  * struct mhi_ep_cntrl - MHI Endpoint controller structure
  75  * @cntrl_dev: Pointer to the struct device of physical bus acting as the MHI
  76  *             Endpoint controller
  77  * @mhi_dev: MHI Endpoint device instance for the controller
  78  * @mmio: MMIO region containing the MHI registers
  79  * @mhi_chan: Points to the channel configuration table
  80  * @mhi_event: Points to the event ring configurations table
  81  * @mhi_cmd: Points to the command ring configurations table
  82  * @sm: MHI Endpoint state machine
  83  * @ch_ctx_cache: Cache of host channel context data structure
  84  * @ev_ctx_cache: Cache of host event context data structure
  85  * @cmd_ctx_cache: Cache of host command context data structure
  86  * @ch_ctx_host_pa: Physical address of host channel context data structure
  87  * @ev_ctx_host_pa: Physical address of host event context data structure
  88  * @cmd_ctx_host_pa: Physical address of host command context data structure
  89  * @ch_ctx_cache_phys: Physical address of the host channel context cache
  90  * @ev_ctx_cache_phys: Physical address of the host event context cache
  91  * @cmd_ctx_cache_phys: Physical address of the host command context cache
  92  * @chdb: Array of channel doorbell interrupt info
  93  * @event_lock: Lock for protecting event rings
  94  * @state_lock: Lock for protecting state transitions
  95  * @list_lock: Lock for protecting state transition and channel doorbell lists
  96  * @st_transition_list: List of state transitions
  97  * @ch_db_list: List of queued channel doorbells
  98  * @wq: Dedicated workqueue for handling rings and state changes
  99  * @state_work: State transition worker
 100  * @reset_work: Worker for MHI Endpoint reset
 101  * @cmd_ring_work: Worker for processing command rings
 102  * @ch_ring_work: Worker for processing channel rings
 103  * @raise_irq: CB function for raising IRQ to the host
 104  * @alloc_map: CB function for allocating memory in endpoint for storing host context and mapping it
 105  * @unmap_free: CB function to unmap and free the allocated memory in endpoint for storing host context
 106  * @read_sync: CB function for reading from host memory synchronously
 107  * @write_sync: CB function for writing to host memory synchronously
 108  * @read_async: CB function for reading from host memory asynchronously
 109  * @write_async: CB function for writing to host memory asynchronously
 110  * @mhi_state: MHI Endpoint state
 111  * @max_chan: Maximum channels supported by the endpoint controller
 112  * @mru: MRU (Maximum Receive Unit) value of the endpoint controller
 113  * @event_rings: Number of event rings supported by the endpoint controller
 114  * @hw_event_rings: Number of hardware event rings supported by the endpoint controller
 115  * @chdb_offset: Channel doorbell offset set by the host
 116  * @erdb_offset: Event ring doorbell offset set by the host
 117  * @index: MHI Endpoint controller index
 118  * @irq: IRQ used by the endpoint controller
 119  * @enabled: Check if the endpoint controller is enabled or not
 120  */
 121 struct mhi_ep_cntrl {
 122         struct device *cntrl_dev;
 123         struct mhi_ep_device *mhi_dev;
 124         void __iomem *mmio;
 125
 126         struct mhi_ep_chan *mhi_chan;
 127         struct mhi_ep_event *mhi_event;
 128         struct mhi_ep_cmd *mhi_cmd;
 129         struct mhi_ep_sm *sm;
 130
 131         struct mhi_chan_ctxt *ch_ctx_cache;
 132         struct mhi_event_ctxt *ev_ctx_cache;
 133         struct mhi_cmd_ctxt *cmd_ctx_cache;
 134         u64 ch_ctx_host_pa;
 135         u64 ev_ctx_host_pa;
 136         u64 cmd_ctx_host_pa;
 137         phys_addr_t ch_ctx_cache_phys;
 138         phys_addr_t ev_ctx_cache_phys;
 139         phys_addr_t cmd_ctx_cache_phys;
 140
 141         struct mhi_ep_db_info chdb[4];
 142         struct mutex event_lock;
 143         struct mutex state_lock;
 144         spinlock_t list_lock;
 145
 146         struct list_head st_transition_list;
 147         struct list_head ch_db_list;
 148
 149         struct workqueue_struct *wq;
 150         struct work_struct state_work;
 151         struct work_struct reset_work;
 152         struct work_struct cmd_ring_work;
 153         struct work_struct ch_ring_work;
 154         struct kmem_cache *ring_item_cache;
 155         struct kmem_cache *ev_ring_el_cache;
 156         struct kmem_cache *tre_buf_cache;
 157
 158         void (*raise_irq)(struct mhi_ep_cntrl *mhi_cntrl, u32 vector);
 159         int (*alloc_map)(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr, phys_addr_t *phys_ptr,
 160                          void __iomem **virt, size_t size);
 161         void (*unmap_free)(struct mhi_ep_cntrl *mhi_cntrl, u64 pci_addr, phys_addr_t phys,
 162                            void __iomem *virt, size_t size);
 163         int (*read_sync)(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_buf_info *buf_info);
 164         int (*write_sync)(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_buf_info *buf_info);
 165         int (*read_async)(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_buf_info *buf_info);
 166         int (*write_async)(struct mhi_ep_cntrl *mhi_cntrl, struct mhi_ep_buf_info *buf_info);
 167
 168         enum mhi_state mhi_state;
 169
 170         u32 max_chan;
 171         u32 mru;
 172         u32 event_rings;
 173         u32 hw_event_rings;
 174         u32 chdb_offset;
 175         u32 erdb_offset;
 176         u32 index;
 177         int irq;
 178         bool enabled;
 179 };
 180
 181 /**
 182  * struct mhi_ep_device - Structure representing an MHI Endpoint device that binds
 183  *                     to channels or is associated with controllers
 184  * @dev: Driver model device node for the MHI Endpoint device
 185  * @mhi_cntrl: Controller the device belongs to
 186  * @id: Pointer to MHI Endpoint device ID struct
 187  * @name: Name of the associated MHI Endpoint device
 188  * @ul_chan: UL (from host to endpoint) channel for the device
 189  * @dl_chan: DL (from endpoint to host) channel for the device
 190  * @dev_type: MHI device type
 191  */
 192 struct mhi_ep_device {
 193         struct device dev;
 194         struct mhi_ep_cntrl *mhi_cntrl;
 195         const struct mhi_device_id *id;
 196         const char *name;
 197         struct mhi_ep_chan *ul_chan;
 198         struct mhi_ep_chan *dl_chan;
 199         enum mhi_device_type dev_type;
 200 };
 201
 202 /**
 203  * struct mhi_ep_driver - Structure representing a MHI Endpoint client driver
 204  * @id_table: Pointer to MHI Endpoint device ID table
 205  * @driver: Device driver model driver
 206  * @probe: CB function for client driver probe function
 207  * @remove: CB function for client driver remove function
 208  * @ul_xfer_cb: CB function for UL (from host to endpoint) data transfer
 209  * @dl_xfer_cb: CB function for DL (from endpoint to host) data transfer
 210  */
 211 struct mhi_ep_driver {
 212         const struct mhi_device_id *id_table;
 213         struct device_driver driver;
 214         int (*probe)(struct mhi_ep_device *mhi_ep,
 215                      const struct mhi_device_id *id);
 216         void (*remove)(struct mhi_ep_device *mhi_ep);
 217         void (*ul_xfer_cb)(struct mhi_ep_device *mhi_dev,
 218                            struct mhi_result *result);
 219         void (*dl_xfer_cb)(struct mhi_ep_device *mhi_dev,
 220                            struct mhi_result *result);
 221 };
 222
 223 #define to_mhi_ep_device(dev) container_of(dev, struct mhi_ep_device, dev)
 224 #define to_mhi_ep_driver(drv) container_of_const(drv, struct mhi_ep_driver, driver)
 225
 226 /*
 227  * module_mhi_ep_driver() - Helper macro for drivers that don't do
 228  * anything special other than using default mhi_ep_driver_register() and
 229  * mhi_ep_driver_unregister().  This eliminates a lot of boilerplate.
 230  * Each module may only use this macro once.
 231  */
 232 #define module_mhi_ep_driver(mhi_drv) \
 233         module_driver(mhi_drv, mhi_ep_driver_register, \
 234                       mhi_ep_driver_unregister)
 235
 236 /*
 237  * Macro to avoid include chaining to get THIS_MODULE
 238  */
 239 #define mhi_ep_driver_register(mhi_drv) \
 240         __mhi_ep_driver_register(mhi_drv, THIS_MODULE)
 241
 242 /**
 243  * __mhi_ep_driver_register - Register a driver with MHI Endpoint bus
 244  * @mhi_drv: Driver to be associated with the device
 245  * @owner: The module owner
 246  *
 247  * Return: 0 if driver registrations succeeds, a negative error code otherwise.
 248  */
 249 int __mhi_ep_driver_register(struct mhi_ep_driver *mhi_drv, struct module *owner);
 250
 251 /**
 252  * mhi_ep_driver_unregister - Unregister a driver from MHI Endpoint bus
 253  * @mhi_drv: Driver associated with the device
 254  */
 255 void mhi_ep_driver_unregister(struct mhi_ep_driver *mhi_drv);
 256
 257 /**
 258  * mhi_ep_register_controller - Register MHI Endpoint controller
 259  * @mhi_cntrl: MHI Endpoint controller to register
 260  * @config: Configuration to use for the controller
 261  *
 262  * Return: 0 if controller registrations succeeds, a negative error code otherwise.
 263  */
 264 int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl,
 265                                const struct mhi_ep_cntrl_config *config);
 266
 267 /**
 268  * mhi_ep_unregister_controller - Unregister MHI Endpoint controller
 269  * @mhi_cntrl: MHI Endpoint controller to unregister
 270  */
 271 void mhi_ep_unregister_controller(struct mhi_ep_cntrl *mhi_cntrl);
 272
 273 /**
 274  * mhi_ep_power_up - Power up the MHI endpoint stack
 275  * @mhi_cntrl: MHI Endpoint controller
 276  *
 277  * Return: 0 if power up succeeds, a negative error code otherwise.
 278  */
 279 int mhi_ep_power_up(struct mhi_ep_cntrl *mhi_cntrl);
 280
 281 /**
 282  * mhi_ep_power_down - Power down the MHI endpoint stack
 283  * @mhi_cntrl: MHI controller
 284  */
 285 void mhi_ep_power_down(struct mhi_ep_cntrl *mhi_cntrl);
 286
 287 /**
 288  * mhi_ep_queue_is_empty - Determine whether the transfer queue is empty
 289  * @mhi_dev: Device associated with the channels
 290  * @dir: DMA direction for the channel
 291  *
 292  * Return: true if the queue is empty, false otherwise.
 293  */
 294 bool mhi_ep_queue_is_empty(struct mhi_ep_device *mhi_dev, enum dma_data_direction dir);
 295
 296 /**
 297  * mhi_ep_queue_skb - Send SKBs to host over MHI Endpoint
 298  * @mhi_dev: Device associated with the DL channel
 299  * @skb: SKBs to be queued
 300  *
 301  * Return: 0 if the SKBs has been sent successfully, a negative error code otherwise.
 302  */
 303 int mhi_ep_queue_skb(struct mhi_ep_device *mhi_dev, struct sk_buff *skb);
 304
 305 #endif