net: wwan: t7xx: Add control DMA interface
Cross Layer DMA (CLDMA) Hardware interface (HIF) enables the control path of Host-Modem data transfers. CLDMA HIF layer provides a common interface to the Port Layer. CLDMA manages 8 independent RX/TX physical channels with data flow control in HW queues. CLDMA uses ring buffers of General Packet Descriptors (GPD) for TX/RX. GPDs can represent multiple or single data buffers (DB). CLDMA HIF initializes GPD rings, registers ISR handlers for CLDMA interrupts, and initializes CLDMA HW registers. CLDMA TX flow: 1. Port Layer write 2. Get DB address 3. Configure GPD 4. Triggering processing via HW register write CLDMA RX flow: 1. CLDMA HW sends a RX "done" to host 2. Driver starts thread to safely read GPD 3. DB is sent to Port layer 4. Create a new buffer for GPD ring Note: This patch does not enable compilation since it has dependencies such as t7xx_pcie_mac_clear_int()/t7xx_pcie_mac_set_int() and struct t7xx_pci_dev which are added by the core patch. Signed-off-by: Haijun Liu <haijun.liu@mediatek.com> Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com> Co-developed-by: Ricardo Martinez <ricardo.martinez@linux.intel.com> Signed-off-by: Ricardo Martinez <ricardo.martinez@linux.intel.com> Reviewed-by: Loic Poulain <loic.poulain@linaro.org> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Sergey Ryazanov <ryazanov.s.a@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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