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author | Octavian Purdila <octavian.purdila@intel.com> | 2014-11-06 15:48:03 +0200 |
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committer | Lee Jones <lee.jones@linaro.org> | 2014-11-10 16:30:05 +0000 |
commit | 338a128142975439a19ab3c91480bc9d5a71f033 (patch) | |
tree | 429db757bfed482b0610b470d1e41e94b5206329 /include/linux/mfd/dln2.h | |
parent | a7975473cc41773d9f6d8ea72b48c7656e6cd0f6 (diff) | |
download | op-kernel-dev-338a128142975439a19ab3c91480bc9d5a71f033.zip op-kernel-dev-338a128142975439a19ab3c91480bc9d5a71f033.tar.gz |
mfd: Add support for Diolan DLN-2 devices
This patch implements the USB part of the Diolan USB-I2C/SPI/GPIO
Master Adapter DLN-2. Details about the device can be found here:
https://www.diolan.com/i2c/i2c_interface.html.
Information about the USB protocol can be found in the Programmer's
Reference Manual [1], see section 1.7.
Because the hardware has a single transmit endpoint and a single
receive endpoint the communication between the various DLN2 drivers
and the hardware will be muxed/demuxed by this driver.
Each DLN2 module will be identified by the handle field within the DLN2
message header. If a DLN2 module issues multiple commands in parallel
they will be identified by the echo counter field in the message header.
The DLN2 modules can use the dln2_transfer() function to issue a
command and wait for its response. They can also register a callback
that is going to be called when a specific event id is generated by
the device (e.g. GPIO interrupts). The device uses handle 0 for
sending events.
[1] https://www.diolan.com/downloads/dln-api-manual.pdf
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Diffstat (limited to 'include/linux/mfd/dln2.h')
-rw-r--r-- | include/linux/mfd/dln2.h | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/include/linux/mfd/dln2.h b/include/linux/mfd/dln2.h new file mode 100644 index 0000000..004b245 --- /dev/null +++ b/include/linux/mfd/dln2.h @@ -0,0 +1,103 @@ +#ifndef __LINUX_USB_DLN2_H +#define __LINUX_USB_DLN2_H + +#define DLN2_CMD(cmd, id) ((cmd) | ((id) << 8)) + +struct dln2_platform_data { + u16 handle; /* sub-driver handle (internally used only) */ + u8 port; /* I2C/SPI port */ +}; + +/** + * dln2_event_cb_t - event callback function signature + * + * @pdev - the sub-device that registered this callback + * @echo - the echo header field received in the message + * @data - the data payload + * @len - the data payload length + * + * The callback function is called in interrupt context and the data payload is + * only valid during the call. If the user needs later access of the data, it + * must copy it. + */ + +typedef void (*dln2_event_cb_t)(struct platform_device *pdev, u16 echo, + const void *data, int len); + +/** + * dl2n_register_event_cb - register a callback function for an event + * + * @pdev - the sub-device that registers the callback + * @event - the event for which to register a callback + * @event_cb - the callback function + * + * @return 0 in case of success, negative value in case of error + */ +int dln2_register_event_cb(struct platform_device *pdev, u16 event, + dln2_event_cb_t event_cb); + +/** + * dln2_unregister_event_cb - unregister the callback function for an event + * + * @pdev - the sub-device that registered the callback + * @event - the event for which to register a callback + */ +void dln2_unregister_event_cb(struct platform_device *pdev, u16 event); + +/** + * dln2_transfer - issue a DLN2 command and wait for a response and the + * associated data + * + * @pdev - the sub-device which is issuing this transfer + * @cmd - the command to be sent to the device + * @obuf - the buffer to be sent to the device; it can be NULL if the user + * doesn't need to transmit data with this command + * @obuf_len - the size of the buffer to be sent to the device + * @ibuf - any data associated with the response will be copied here; it can be + * NULL if the user doesn't need the response data + * @ibuf_len - must be initialized to the input buffer size; it will be modified + * to indicate the actual data transferred; + * + * @return 0 for success, negative value for errors + */ +int dln2_transfer(struct platform_device *pdev, u16 cmd, + const void *obuf, unsigned obuf_len, + void *ibuf, unsigned *ibuf_len); + +/** + * dln2_transfer_rx - variant of @dln2_transfer() where TX buffer is not needed + * + * @pdev - the sub-device which is issuing this transfer + * @cmd - the command to be sent to the device + * @ibuf - any data associated with the response will be copied here; it can be + * NULL if the user doesn't need the response data + * @ibuf_len - must be initialized to the input buffer size; it will be modified + * to indicate the actual data transferred; + * + * @return 0 for success, negative value for errors + */ + +static inline int dln2_transfer_rx(struct platform_device *pdev, u16 cmd, + void *ibuf, unsigned *ibuf_len) +{ + return dln2_transfer(pdev, cmd, NULL, 0, ibuf, ibuf_len); +} + +/** + * dln2_transfer_tx - variant of @dln2_transfer() where RX buffer is not needed + * + * @pdev - the sub-device which is issuing this transfer + * @cmd - the command to be sent to the device + * @obuf - the buffer to be sent to the device; it can be NULL if the + * user doesn't need to transmit data with this command + * @obuf_len - the size of the buffer to be sent to the device + * + * @return 0 for success, negative value for errors + */ +static inline int dln2_transfer_tx(struct platform_device *pdev, u16 cmd, + const void *obuf, unsigned obuf_len) +{ + return dln2_transfer(pdev, cmd, obuf, obuf_len, NULL, NULL); +} + +#endif |