[media] v4l: ti-vpe: Create a vpdma helper library
The primary function of VPDMA is to move data between external memory and internal processing modules(in our case, VPE) that source or sink data. VPDMA is capable of buffering this data and then delivering the data as demanded to the modules as programmed. The modules that source or sink data are referred to as clients or ports. A channel is setup inside the VPDMA to connect a specific memory buffer to a specific client. The VPDMA centralizes the DMA control functions and buffering required to allow all the clients to minimize the effect of long latency times. Add the following to the VPDMA helper: - A data struct which describe VPDMA channels. For now, these channels are the ones used only by VPE, the list of channels will increase when VIP(Video Input Port) also uses the VPDMA library. This channel information will be used to populate fields required by data descriptors. - Data structs which describe the different data types supported by VPDMA. This data type information will be used to populate fields required by data descriptors and used by the VPE driver to map a V4L2 format to the corresponding VPDMA data type. - Provide VPDMA register offset definitions, functions to read, write and modify VPDMA registers. - Functions to create and submit a VPDMA list. A list is a group of descriptors that makes up a set of DMA transfers that need to be completed. Each descriptor will either perform a DMA transaction to fetch input buffers and write to output buffers(data descriptors), or configure the MMRs of sub blocks of VPE(configuration descriptors), or provide control information to VPDMA (control descriptors). - Functions to allocate, map and unmap buffers needed for the descriptor list, payloads containing MMR values and scaler coefficients. These use the DMA mapping APIs to ensure exclusive access to VPDMA. - Functions to enable VPDMA interrupts. VPDMA can trigger an interrupt on the VPE interrupt line when a descriptor list is parsed completely and the DMA transactions are completed. This requires masking the events in VPDMA registers and configuring some top level VPE interrupt registers. - Enable some VPDMA specific parameters: frame start event(when to start DMA for a client) and line mode(whether each line fetched should be mirrored or not). - Function to load firmware required by VPDMA. VPDMA requires a firmware for it's internal list manager. We add the required request_firmware apis to fetch this firmware from user space. - Function to dump VPDMA registers. - A function to initialize and create a VPDMA instance, this will be called by the VPE driver with it's platform device pointer, this function will take care of loading VPDMA firmware and returning a vpdma_data instance back to the VPE driver. The VIP driver will also call the same init function to initialize it's own VPDMA instance. Signed-off-by: Archit Taneja <archit@ti.com> Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Kamil Debski <k.debski@samsung.com> Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
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