On Wed, Mar 25, 2015 at 03:39:50PM +0000, James Hogan wrote: > Add MIPS Common Device Memory Map (CDMM) support in the form of a bus in > the standard Linux device model. Each device attached via CDMM is > discoverable via an 8-bit type identifier and may contain a number of > blocks of memory mapped registers in the CDMM region. IRQs are expected > to be handled separately. > > Due to the per-cpu (per-VPE for MT cores) nature of the CDMM devices, > all the driver callbacks take place from workqueues which are run on the > right CPU for the device in question, so that the driver doesn't need to > be as concerned about which CPU it is running on. Callbacks also exist > for when CPUs are taken offline, so that any per-CPU resources used by > the driver can be disabled so they don't get forcefully migrated. CDMM > devices are created as children of the CPU device they are attached to. > > Any existing CDMM configuration by the bootloader will be inherited, > however platforms wishing to enable CDMM should implement the weak > mips_cdmm_phys_base() function (see asm/cdmm.h) so that the bus driver > knows where it should put the CDMM region in the physical address space > if the bootloader hasn't already enabled it. > > A mips_cdmm_early_probe() function is also provided to allow early boot > or particularly low level code to set up the CDMM region and probe for a > specific device type, for example early console or KGDB IO drivers for > the EJTAG Fast Debug Channel (FDC) CDMM device. > > Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx> > Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: linux-mips@xxxxxxxxxxxxxx > --- > Changes in v3: > - Convert to use dev_groups rather than dev_attrs (GregKH). > - Rename mips_cdmm_attr_func() macro to CDMM_ATTR for consistency with > other similar macro names I've seen around the kernel. > - Add modalias attribute. > > Changes in v2: > - Fix some checkpatch errors. > - Correct CDMM name in various places. It is "Common Device Memory Map", > rather than "Common Device Mapped Memory" (which for some reason had > got stuck in my head). > --- > arch/mips/include/asm/cdmm.h | 87 +++++ > drivers/bus/Kconfig | 13 + > drivers/bus/Makefile | 1 + > drivers/bus/mips_cdmm.c | 716 ++++++++++++++++++++++++++++++++++++++ > include/linux/mod_devicetable.h | 8 + > scripts/mod/devicetable-offsets.c | 3 + > scripts/mod/file2alias.c | 16 + > 7 files changed, 844 insertions(+) > create mode 100644 arch/mips/include/asm/cdmm.h > create mode 100644 drivers/bus/mips_cdmm.c Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
