1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_USB_DLN2_H
3 #define __LINUX_USB_DLN2_H
4 
5 #define DLN2_CMD(cmd, id)		((cmd) | ((id) << 8))
6 
7 struct dln2_platform_data {
8 	u16 handle;		/* sub-driver handle (internally used only) */
9 	u8 port;		/* I2C/SPI port */
10 };
11 
12 /**
13  * dln2_event_cb_t - event callback function signature
14  *
15  * @pdev - the sub-device that registered this callback
16  * @echo - the echo header field received in the message
17  * @data - the data payload
18  * @len  - the data payload length
19  *
20  * The callback function is called in interrupt context and the data payload is
21  * only valid during the call. If the user needs later access of the data, it
22  * must copy it.
23  */
24 
25 typedef void (*dln2_event_cb_t)(struct platform_device *pdev, u16 echo,
26 				const void *data, int len);
27 
28 /**
29  * dl2n_register_event_cb - register a callback function for an event
30  *
31  * @pdev - the sub-device that registers the callback
32  * @event - the event for which to register a callback
33  * @event_cb - the callback function
34  *
35  * @return 0 in case of success, negative value in case of error
36  */
37 int dln2_register_event_cb(struct platform_device *pdev, u16 event,
38 			   dln2_event_cb_t event_cb);
39 
40 /**
41  * dln2_unregister_event_cb - unregister the callback function for an event
42  *
43  * @pdev - the sub-device that registered the callback
44  * @event - the event for which to register a callback
45  */
46 void dln2_unregister_event_cb(struct platform_device *pdev, u16 event);
47 
48 /**
49  * dln2_transfer - issue a DLN2 command and wait for a response and the
50  * associated data
51  *
52  * @pdev - the sub-device which is issuing this transfer
53  * @cmd - the command to be sent to the device
54  * @obuf - the buffer to be sent to the device; it can be NULL if the user
55  *	doesn't need to transmit data with this command
56  * @obuf_len - the size of the buffer to be sent to the device
57  * @ibuf - any data associated with the response will be copied here; it can be
58  *	NULL if the user doesn't need the response data
59  * @ibuf_len - must be initialized to the input buffer size; it will be modified
60  *	to indicate the actual data transferred;
61  *
62  * @return 0 for success, negative value for errors
63  */
64 int dln2_transfer(struct platform_device *pdev, u16 cmd,
65 		  const void *obuf, unsigned obuf_len,
66 		  void *ibuf, unsigned *ibuf_len);
67 
68 /**
69  * dln2_transfer_rx - variant of @dln2_transfer() where TX buffer is not needed
70  *
71  * @pdev - the sub-device which is issuing this transfer
72  * @cmd - the command to be sent to the device
73  * @ibuf - any data associated with the response will be copied here; it can be
74  *	NULL if the user doesn't need the response data
75  * @ibuf_len - must be initialized to the input buffer size; it will be modified
76  *	to indicate the actual data transferred;
77  *
78  * @return 0 for success, negative value for errors
79  */
80 
dln2_transfer_rx(struct platform_device * pdev,u16 cmd,void * ibuf,unsigned * ibuf_len)81 static inline int dln2_transfer_rx(struct platform_device *pdev, u16 cmd,
82 				   void *ibuf, unsigned *ibuf_len)
83 {
84 	return dln2_transfer(pdev, cmd, NULL, 0, ibuf, ibuf_len);
85 }
86 
87 /**
88  * dln2_transfer_tx - variant of @dln2_transfer() where RX buffer is not needed
89  *
90  * @pdev - the sub-device which is issuing this transfer
91  * @cmd - the command to be sent to the device
92  * @obuf - the buffer to be sent to the device; it can be NULL if the
93  *	user doesn't need to transmit data with this command
94  * @obuf_len - the size of the buffer to be sent to the device
95  *
96  * @return 0 for success, negative value for errors
97  */
dln2_transfer_tx(struct platform_device * pdev,u16 cmd,const void * obuf,unsigned obuf_len)98 static inline int dln2_transfer_tx(struct platform_device *pdev, u16 cmd,
99 				   const void *obuf, unsigned obuf_len)
100 {
101 	return dln2_transfer(pdev, cmd, obuf, obuf_len, NULL, NULL);
102 }
103 
104 #endif
105