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authorOctavian Purdila <octavian.purdila@intel.com>2014-11-06 16:48:03 +0300
committerLee Jones <lee.jones@linaro.org>2014-11-10 19:30:05 +0300
commit338a128142975439a19ab3c91480bc9d5a71f033 (patch)
tree429db757bfed482b0610b470d1e41e94b5206329 /include/linux/mfd
parenta7975473cc41773d9f6d8ea72b48c7656e6cd0f6 (diff)
downloadlinux-338a128142975439a19ab3c91480bc9d5a71f033.tar.xz
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')
-rw-r--r--include/linux/mfd/dln2.h103
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 000000000000..004b24576da8
--- /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