1 /*
2  * Copyright (C) ST-Ericsson SA 2010
3  * Author: Stefan Nilsson <stefan.xk.nilsson@stericsson.com> for ST-Ericsson.
4  * Author: Martin Persson <martin.persson@stericsson.com> for ST-Ericsson.
5  * License terms: GNU General Public License (GPL), version 2.
6  */
7 
8 #ifndef __INC_STE_MBOX_H
9 #define __INC_STE_MBOX_H
10 
11 #define MBOX_BUF_SIZE 16
12 #define MBOX_NAME_SIZE 8
13 
14 /**
15   * mbox_recv_cb_t - Definition of the mailbox callback.
16   * @mbox_msg:	The mailbox message.
17   * @priv:	The clients private data as specified in the call to mbox_setup.
18   *
19   * This function will be called upon reception of new mailbox messages.
20   */
21 typedef void mbox_recv_cb_t (u32 mbox_msg, void *priv);
22 
23 /**
24   * struct mbox - Mailbox instance struct
25   * @list:		Linked list head.
26   * @pdev:		Pointer to device struct.
27   * @cb:		Callback function. Will be called
28   *			when new data is received.
29   * @client_data:	Clients private data. Will be sent back
30   *			in the callback function.
31   * @virtbase_peer:	Virtual address for outgoing mailbox.
32   * @virtbase_local:	Virtual address for incoming mailbox.
33   * @buffer:		Then internal queue for outgoing messages.
34   * @name:		Name of this mailbox.
35   * @buffer_available:	Completion variable to achieve "blocking send".
36   *			This variable will be signaled when there is
37   *			internal buffer space available.
38   * @client_blocked:	To keep track if any client is currently
39   *			blocked.
40   * @lock:		Spinlock to protect this mailbox instance.
41   * @write_index:	Index in internal buffer to write to.
42   * @read_index:	Index in internal buffer to read from.
43   * @allocated:		Indicates whether this particular mailbox
44   *			id has been allocated by someone.
45   */
46 struct mbox {
47 	struct list_head list;
48 	struct platform_device *pdev;
49 	mbox_recv_cb_t *cb;
50 	void *client_data;
51 	void __iomem *virtbase_peer;
52 	void __iomem *virtbase_local;
53 	u32 buffer[MBOX_BUF_SIZE];
54 	char name[MBOX_NAME_SIZE];
55 	struct completion buffer_available;
56 	u8 client_blocked;
57 	spinlock_t lock;
58 	u8 write_index;
59 	u8 read_index;
60 	bool allocated;
61 };
62 
63 /**
64   * mbox_setup - Set up a mailbox and return its instance.
65   * @mbox_id:	The ID number of the mailbox. 0 or 1 for modem CPU,
66   *		2 for modem DSP.
67   * @mbox_cb:	Pointer to the callback function to be called when a new message
68   *		is received.
69   * @priv:	Client user data which will be returned in the callback.
70   *
71   * Returns a mailbox instance to be specified in subsequent calls to mbox_send.
72   */
73 struct mbox *mbox_setup(u8 mbox_id, mbox_recv_cb_t *mbox_cb, void *priv);
74 
75 /**
76   * mbox_send - Send a mailbox message.
77   * @mbox:	Mailbox instance (returned by mbox_setup)
78   * @mbox_msg:	The mailbox message to send.
79   * @block:	Specifies whether this call will block until send is possible,
80   *		or return an error if the mailbox buffer is full.
81   *
82   * Returns 0 on success or a negative error code on error. -ENOMEM indicates
83   * that the internal buffer is full and you have to try again later (or
84   * specify "block" in order to block until send is possible).
85   */
86 int mbox_send(struct mbox *mbox, u32 mbox_msg, bool block);
87 
88 #endif /*INC_STE_MBOX_H*/
89