The Allwinner SoCs have a handful of SRAM that can be either mapped to be
accessible by devices or the CPU.
That mapping is controlled by an SRAM controller, and that mapping might
not be set by the bootloader, for example if the device wasn't used at all,
or if we're using solutions like the U-Boot's Falcon Boot.
We could also imagine changing this at runtime for example to change the
mapping of these SRAMs to use them for suspend/resume or runtime memory
rate change, if that ever happens.
These use cases require some API in the kernel to control that mapping,
exported through a drivers/soc driver.
This driver also implement a debugfs file that shows the SRAM found in the
system, the current mapping and the SRAM that have been claimed by some
drivers in the kernel.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes below build break by not switching to stubs when the driver is a module:
drivers/soc/ti/knav_dma.c:418:7: error: redefinition of 'knav_dma_open_channel'
void *knav_dma_open_channel(struct device *dev, const char *name,
^
In file included from drivers/soc/ti/knav_dma.c:26:0:
include/linux/soc/ti/knav_dma.h:165:21: note: previous definition of 'knav_dma_open_channel' was here
static inline void *knav_dma_open_channel(struct device *dev, const char *name,
^
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
The Keystone Navigator DMA driver sets up the dma channels and flows for
the QMSS(Queue Manager SubSystem) who triggers the actual data movements
across clients using destination queues. Every client modules like
NETCP(Network Coprocessor), SRIO(Serial Rapid IO) and CRYPTO
Engines has its own instance of packet dma hardware. QMSS has also
an internal packet DMA module which is used as an infrastructure
DMA with zero copy.
Initially this driver was proposed as DMA engine driver but since the
hardware is not typical DMA engine and hence doesn't comply with typical
DMA engine driver needs, that approach was naked. Link to that
discussion -
https://lkml.org/lkml/2014/3/18/340
As aligned, now we pair the Navigator DMA with its companion Navigator
QMSS subsystem driver.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sandeep Nair <sandeep_n@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
The QMSS (Queue Manager Sub System) found on Keystone SOCs is one of
the main hardware sub system which forms the backbone of the Keystone
Multi-core Navigator. QMSS consist of queue managers, packed-data structure
processors(PDSP), linking RAM, descriptor pools and infrastructure
Packet DMA.
The Queue Manager is a hardware module that is responsible for accelerating
management of the packet queues. Packets are queued/de-queued by writing or
reading descriptor address to a particular memory mapped location. The PDSPs
perform QMSS related functions like accumulation, QoS, or event management.
Linking RAM registers are used to link the descriptors which are stored in
descriptor RAM. Descriptor RAM is configurable as internal or external memory.
The QMSS driver manages the PDSP setups, linking RAM regions,
queue pool management (allocation, push, pop and notify) and descriptor
pool management. The specifics on the device tree bindings for
QMSS can be found in:
Documentation/devicetree/bindings/soc/keystone-navigator-qmss.txt
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sandeep Nair <sandeep_n@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
