bus: mhi: core: Add support for data transfer

Add support for transferring data between external modem and host
processor using MHI protocol.

This is based on the patch submitted by Sujeev Dias:
https://lkml.org/lkml/2018/7/9/988

Signed-off-by: Sujeev Dias <sdias@codeaurora.org>
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
[mani: splitted the data transfer patch and cleaned up for upstream]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Tested-by: Jeffrey Hugo <jhugo@codeaurora.org>
Link: https://lore.kernel.org/r/20200220095854.4804-12-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 80 insertions, 0 deletions

diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index bf8921ee0805..79cb9f898544 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -10,6 +10,7 @@
 #include <linux/dma-direction.h>
 #include <linux/mutex.h>
 #include <linux/rwlock_types.h>
+#include <linux/skbuff.h>
 #include <linux/slab.h>
 #include <linux/spinlock_types.h>
 #include <linux/wait.h>
@@ -336,6 +337,8 @@ struct mhi_controller_config {
  * @wake_toggle: CB function to assert and de-assert device wake (optional)
  * @runtime_get: CB function to controller runtime resume (required)
  * @runtimet_put: CB function to decrement pm usage (required)
+ * @map_single: CB function to create TRE buffer
+ * @unmap_single: CB function to destroy TRE buffer
  * @buffer_len: Bounce buffer length
  * @bounce_buf: Use of bounce buffer
  * @fbc_download: MHI host needs to do complete image transfer (optional)
@@ -403,6 +406,10 @@ struct mhi_controller {
 	void (*wake_toggle)(struct mhi_controller *mhi_cntrl);
 	int (*runtime_get)(struct mhi_controller *mhi_cntrl);
 	void (*runtime_put)(struct mhi_controller *mhi_cntrl);
+	int (*map_single)(struct mhi_controller *mhi_cntrl,
+			  struct mhi_buf_info *buf);
+	void (*unmap_single)(struct mhi_controller *mhi_cntrl,
+			     struct mhi_buf_info *buf);
 
 	size_t buffer_len;
 	bool bounce_buf;
@@ -583,4 +590,77 @@ int mhi_force_rddm_mode(struct mhi_controller *mhi_cntrl);
  */
 enum mhi_state mhi_get_mhi_state(struct mhi_controller *mhi_cntrl);
 
+/**
+ * mhi_device_get - Disable device low power mode
+ * @mhi_dev: Device associated with the channel
+ */
+void mhi_device_get(struct mhi_device *mhi_dev);
+
+/**
+ * mhi_device_get_sync - Disable device low power mode. Synchronously
+ *                       take the controller out of suspended state
+ * @mhi_dev: Device associated with the channel
+ */
+int mhi_device_get_sync(struct mhi_device *mhi_dev);
+
+/**
+ * mhi_device_put - Re-enable device low power mode
+ * @mhi_dev: Device associated with the channel
+ */
+void mhi_device_put(struct mhi_device *mhi_dev);
+
+/**
+ * mhi_prepare_for_transfer - Setup channel for data transfer
+ * @mhi_dev: Device associated with the channels
+ */
+int mhi_prepare_for_transfer(struct mhi_device *mhi_dev);
+
+/**
+ * mhi_unprepare_from_transfer - Unprepare the channels
+ * @mhi_dev: Device associated with the channels
+ */
+void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev);
+
+/**
+ * mhi_poll - Poll for any available data in DL direction
+ * @mhi_dev: Device associated with the channels
+ * @budget: # of events to process
+ */
+int mhi_poll(struct mhi_device *mhi_dev, u32 budget);
+
+/**
+ * mhi_queue_dma - Send or receive DMA mapped buffers from client device
+ *                 over MHI channel
+ * @mhi_dev: Device associated with the channels
+ * @dir: DMA direction for the channel
+ * @mhi_buf: Buffer for holding the DMA mapped data
+ * @len: Buffer length
+ * @mflags: MHI transfer flags used for the transfer
+ */
+int mhi_queue_dma(struct mhi_device *mhi_dev, enum dma_data_direction dir,
+		  struct mhi_buf *mhi_buf, size_t len, enum mhi_flags mflags);
+
+/**
+ * mhi_queue_buf - Send or receive raw buffers from client device over MHI
+ *                 channel
+ * @mhi_dev: Device associated with the channels
+ * @dir: DMA direction for the channel
+ * @buf: Buffer for holding the data
+ * @len: Buffer length
+ * @mflags: MHI transfer flags used for the transfer
+ */
+int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir,
+		  void *buf, size_t len, enum mhi_flags mflags);
+
+/**
+ * mhi_queue_skb - Send or receive SKBs from client device over MHI channel
+ * @mhi_dev: Device associated with the channels
+ * @dir: DMA direction for the channel
+ * @skb: Buffer for holding SKBs
+ * @len: Buffer length
+ * @mflags: MHI transfer flags used for the transfer
+ */
+int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir,
+		  struct sk_buff *skb, size_t len, enum mhi_flags mflags);
+
 #endif /* _MHI_H_ */