linux/mfd/dln2.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef __LINUX_USB_DLN2_H
0003 #define __LINUX_USB_DLN2_H
0004
0005 #define DLN2_CMD(cmd, id)       ((cmd) | ((id) << 8))
0006
0007 struct dln2_platform_data {
0008     u16 handle;     /* sub-driver handle (internally used only) */
0009     u8 port;        /* I2C/SPI port */
0010 };
0011
0012 /**
0013  * dln2_event_cb_t - event callback function signature
0014  *
0015  * @pdev - the sub-device that registered this callback
0016  * @echo - the echo header field received in the message
0017  * @data - the data payload
0018  * @len  - the data payload length
0019  *
0020  * The callback function is called in interrupt context and the data payload is
0021  * only valid during the call. If the user needs later access of the data, it
0022  * must copy it.
0023  */
0024
0025 typedef void (*dln2_event_cb_t)(struct platform_device *pdev, u16 echo,
0026                 const void *data, int len);
0027
0028 /**
0029  * dl2n_register_event_cb - register a callback function for an event
0030  *
0031  * @pdev - the sub-device that registers the callback
0032  * @event - the event for which to register a callback
0033  * @event_cb - the callback function
0034  *
0035  * @return 0 in case of success, negative value in case of error
0036  */
0037 int dln2_register_event_cb(struct platform_device *pdev, u16 event,
0038                dln2_event_cb_t event_cb);
0039
0040 /**
0041  * dln2_unregister_event_cb - unregister the callback function for an event
0042  *
0043  * @pdev - the sub-device that registered the callback
0044  * @event - the event for which to register a callback
0045  */
0046 void dln2_unregister_event_cb(struct platform_device *pdev, u16 event);
0047
0048 /**
0049  * dln2_transfer - issue a DLN2 command and wait for a response and the
0050  * associated data
0051  *
0052  * @pdev - the sub-device which is issuing this transfer
0053  * @cmd - the command to be sent to the device
0054  * @obuf - the buffer to be sent to the device; it can be NULL if the user
0055  *  doesn't need to transmit data with this command
0056  * @obuf_len - the size of the buffer to be sent to the device
0057  * @ibuf - any data associated with the response will be copied here; it can be
0058  *  NULL if the user doesn't need the response data
0059  * @ibuf_len - must be initialized to the input buffer size; it will be modified
0060  *  to indicate the actual data transferred;
0061  *
0062  * @return 0 for success, negative value for errors
0063  */
0064 int dln2_transfer(struct platform_device *pdev, u16 cmd,
0065           const void *obuf, unsigned obuf_len,
0066           void *ibuf, unsigned *ibuf_len);
0067
0068 /**
0069  * dln2_transfer_rx - variant of @dln2_transfer() where TX buffer is not needed
0070  *
0071  * @pdev - the sub-device which is issuing this transfer
0072  * @cmd - the command to be sent to the device
0073  * @ibuf - any data associated with the response will be copied here; it can be
0074  *  NULL if the user doesn't need the response data
0075  * @ibuf_len - must be initialized to the input buffer size; it will be modified
0076  *  to indicate the actual data transferred;
0077  *
0078  * @return 0 for success, negative value for errors
0079  */
0080
0081 static inline int dln2_transfer_rx(struct platform_device *pdev, u16 cmd,
0082                    void *ibuf, unsigned *ibuf_len)
0083 {
0084     return dln2_transfer(pdev, cmd, NULL, 0, ibuf, ibuf_len);
0085 }
0086
0087 /**
0088  * dln2_transfer_tx - variant of @dln2_transfer() where RX buffer is not needed
0089  *
0090  * @pdev - the sub-device which is issuing this transfer
0091  * @cmd - the command to be sent to the device
0092  * @obuf - the buffer to be sent to the device; it can be NULL if the
0093  *  user doesn't need to transmit data with this command
0094  * @obuf_len - the size of the buffer to be sent to the device
0095  *
0096  * @return 0 for success, negative value for errors
0097  */
0098 static inline int dln2_transfer_tx(struct platform_device *pdev, u16 cmd,
0099                    const void *obuf, unsigned obuf_len)
0100 {
0101     return dln2_transfer(pdev, cmd, obuf, obuf_len, NULL, NULL);
0102 }
0103
0104 #endif