xref: /openbmc/linux/include/linux/mfd/dln2.h (revision e0bf6c5c)
1 #ifndef __LINUX_USB_DLN2_H
2 #define __LINUX_USB_DLN2_H
3 
4 #define DLN2_CMD(cmd, id)		((cmd) | ((id) << 8))
5 
6 struct dln2_platform_data {
7 	u16 handle;		/* sub-driver handle (internally used only) */
8 	u8 port;		/* I2C/SPI port */
9 };
10 
11 /**
12  * dln2_event_cb_t - event callback function signature
13  *
14  * @pdev - the sub-device that registered this callback
15  * @echo - the echo header field received in the message
16  * @data - the data payload
17  * @len  - the data payload length
18  *
19  * The callback function is called in interrupt context and the data payload is
20  * only valid during the call. If the user needs later access of the data, it
21  * must copy it.
22  */
23 
24 typedef void (*dln2_event_cb_t)(struct platform_device *pdev, u16 echo,
25 				const void *data, int len);
26 
27 /**
28  * dl2n_register_event_cb - register a callback function for an event
29  *
30  * @pdev - the sub-device that registers the callback
31  * @event - the event for which to register a callback
32  * @event_cb - the callback function
33  *
34  * @return 0 in case of success, negative value in case of error
35  */
36 int dln2_register_event_cb(struct platform_device *pdev, u16 event,
37 			   dln2_event_cb_t event_cb);
38 
39 /**
40  * dln2_unregister_event_cb - unregister the callback function for an event
41  *
42  * @pdev - the sub-device that registered the callback
43  * @event - the event for which to register a callback
44  */
45 void dln2_unregister_event_cb(struct platform_device *pdev, u16 event);
46 
47 /**
48  * dln2_transfer - issue a DLN2 command and wait for a response and the
49  * associated data
50  *
51  * @pdev - the sub-device which is issuing this transfer
52  * @cmd - the command to be sent to the device
53  * @obuf - the buffer to be sent to the device; it can be NULL if the user
54  *	doesn't need to transmit data with this command
55  * @obuf_len - the size of the buffer to be sent to the device
56  * @ibuf - any data associated with the response will be copied here; it can be
57  *	NULL if the user doesn't need the response data
58  * @ibuf_len - must be initialized to the input buffer size; it will be modified
59  *	to indicate the actual data transferred;
60  *
61  * @return 0 for success, negative value for errors
62  */
63 int dln2_transfer(struct platform_device *pdev, u16 cmd,
64 		  const void *obuf, unsigned obuf_len,
65 		  void *ibuf, unsigned *ibuf_len);
66 
67 /**
68  * dln2_transfer_rx - variant of @dln2_transfer() where TX buffer is not needed
69  *
70  * @pdev - the sub-device which is issuing this transfer
71  * @cmd - the command to be sent to the device
72  * @ibuf - any data associated with the response will be copied here; it can be
73  *	NULL if the user doesn't need the response data
74  * @ibuf_len - must be initialized to the input buffer size; it will be modified
75  *	to indicate the actual data transferred;
76  *
77  * @return 0 for success, negative value for errors
78  */
79 
80 static inline int dln2_transfer_rx(struct platform_device *pdev, u16 cmd,
81 				   void *ibuf, unsigned *ibuf_len)
82 {
83 	return dln2_transfer(pdev, cmd, NULL, 0, ibuf, ibuf_len);
84 }
85 
86 /**
87  * dln2_transfer_tx - variant of @dln2_transfer() where RX buffer is not needed
88  *
89  * @pdev - the sub-device which is issuing this transfer
90  * @cmd - the command to be sent to the device
91  * @obuf - the buffer to be sent to the device; it can be NULL if the
92  *	user doesn't need to transmit data with this command
93  * @obuf_len - the size of the buffer to be sent to the device
94  *
95  * @return 0 for success, negative value for errors
96  */
97 static inline int dln2_transfer_tx(struct platform_device *pdev, u16 cmd,
98 				   const void *obuf, unsigned obuf_len)
99 {
100 	return dln2_transfer(pdev, cmd, obuf, obuf_len, NULL, NULL);
101 }
102 
103 #endif
104