You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
134 lines
5.4 KiB
134 lines
5.4 KiB
/* |
|
* This program is free software; you can redistribute it and/or modify |
|
* it under the terms of the GNU General Public License version 2 as |
|
* published by the Free Software Foundation. |
|
*/ |
|
|
|
#ifndef __MAILBOX_CONTROLLER_H |
|
#define __MAILBOX_CONTROLLER_H |
|
|
|
#include <linux/of.h> |
|
#include <linux/types.h> |
|
#include <linux/hrtimer.h> |
|
#include <linux/device.h> |
|
#include <linux/completion.h> |
|
|
|
struct mbox_chan; |
|
|
|
/** |
|
* struct mbox_chan_ops - methods to control mailbox channels |
|
* @send_data: The API asks the MBOX controller driver, in atomic |
|
* context try to transmit a message on the bus. Returns 0 if |
|
* data is accepted for transmission, -EBUSY while rejecting |
|
* if the remote hasn't yet read the last data sent. Actual |
|
* transmission of data is reported by the controller via |
|
* mbox_chan_txdone (if it has some TX ACK irq). It must not |
|
* sleep. |
|
* @startup: Called when a client requests the chan. The controller |
|
* could ask clients for additional parameters of communication |
|
* to be provided via client's chan_data. This call may |
|
* block. After this call the Controller must forward any |
|
* data received on the chan by calling mbox_chan_received_data. |
|
* The controller may do stuff that need to sleep. |
|
* @shutdown: Called when a client relinquishes control of a chan. |
|
* This call may block too. The controller must not forward |
|
* any received data anymore. |
|
* The controller may do stuff that need to sleep. |
|
* @last_tx_done: If the controller sets 'txdone_poll', the API calls |
|
* this to poll status of last TX. The controller must |
|
* give priority to IRQ method over polling and never |
|
* set both txdone_poll and txdone_irq. Only in polling |
|
* mode 'send_data' is expected to return -EBUSY. |
|
* The controller may do stuff that need to sleep/block. |
|
* Used only if txdone_poll:=true && txdone_irq:=false |
|
* @peek_data: Atomic check for any received data. Return true if controller |
|
* has some data to push to the client. False otherwise. |
|
*/ |
|
struct mbox_chan_ops { |
|
int (*send_data)(struct mbox_chan *chan, void *data); |
|
int (*startup)(struct mbox_chan *chan); |
|
void (*shutdown)(struct mbox_chan *chan); |
|
bool (*last_tx_done)(struct mbox_chan *chan); |
|
bool (*peek_data)(struct mbox_chan *chan); |
|
}; |
|
|
|
/** |
|
* struct mbox_controller - Controller of a class of communication channels |
|
* @dev: Device backing this controller |
|
* @ops: Operators that work on each communication chan |
|
* @chans: Array of channels |
|
* @num_chans: Number of channels in the 'chans' array. |
|
* @txdone_irq: Indicates if the controller can report to API when |
|
* the last transmitted data was read by the remote. |
|
* Eg, if it has some TX ACK irq. |
|
* @txdone_poll: If the controller can read but not report the TX |
|
* done. Ex, some register shows the TX status but |
|
* no interrupt rises. Ignored if 'txdone_irq' is set. |
|
* @txpoll_period: If 'txdone_poll' is in effect, the API polls for |
|
* last TX's status after these many millisecs |
|
* @of_xlate: Controller driver specific mapping of channel via DT |
|
* @poll_hrt: API private. hrtimer used to poll for TXDONE on all |
|
* channels. |
|
* @node: API private. To hook into list of controllers. |
|
*/ |
|
struct mbox_controller { |
|
struct device *dev; |
|
const struct mbox_chan_ops *ops; |
|
struct mbox_chan *chans; |
|
int num_chans; |
|
bool txdone_irq; |
|
bool txdone_poll; |
|
unsigned txpoll_period; |
|
struct mbox_chan *(*of_xlate)(struct mbox_controller *mbox, |
|
const struct of_phandle_args *sp); |
|
/* Internal to API */ |
|
struct hrtimer poll_hrt; |
|
struct list_head node; |
|
}; |
|
|
|
/* |
|
* The length of circular buffer for queuing messages from a client. |
|
* 'msg_count' tracks the number of buffered messages while 'msg_free' |
|
* is the index where the next message would be buffered. |
|
* We shouldn't need it too big because every transfer is interrupt |
|
* triggered and if we have lots of data to transfer, the interrupt |
|
* latencies are going to be the bottleneck, not the buffer length. |
|
* Besides, mbox_send_message could be called from atomic context and |
|
* the client could also queue another message from the notifier 'tx_done' |
|
* of the last transfer done. |
|
* REVISIT: If too many platforms see the "Try increasing MBOX_TX_QUEUE_LEN" |
|
* print, it needs to be taken from config option or somesuch. |
|
*/ |
|
#define MBOX_TX_QUEUE_LEN 20 |
|
|
|
/** |
|
* struct mbox_chan - s/w representation of a communication chan |
|
* @mbox: Pointer to the parent/provider of this channel |
|
* @txdone_method: Way to detect TXDone chosen by the API |
|
* @cl: Pointer to the current owner of this channel |
|
* @tx_complete: Transmission completion |
|
* @active_req: Currently active request hook |
|
* @msg_count: No. of mssg currently queued |
|
* @msg_free: Index of next available mssg slot |
|
* @msg_data: Hook for data packet |
|
* @lock: Serialise access to the channel |
|
* @con_priv: Hook for controller driver to attach private data |
|
*/ |
|
struct mbox_chan { |
|
struct mbox_controller *mbox; |
|
unsigned txdone_method; |
|
struct mbox_client *cl; |
|
struct completion tx_complete; |
|
void *active_req; |
|
unsigned msg_count, msg_free; |
|
void *msg_data[MBOX_TX_QUEUE_LEN]; |
|
spinlock_t lock; /* Serialise access to the channel */ |
|
void *con_priv; |
|
}; |
|
|
|
int mbox_controller_register(struct mbox_controller *mbox); /* can sleep */ |
|
void mbox_controller_unregister(struct mbox_controller *mbox); /* can sleep */ |
|
void mbox_chan_received_data(struct mbox_chan *chan, void *data); /* atomic */ |
|
void mbox_chan_txdone(struct mbox_chan *chan, int r); /* atomic */ |
|
|
|
#endif /* __MAILBOX_CONTROLLER_H */
|
|
|