[U-Boot] [PATCH v8 4/8] ARM: socfpga: Add FPGA drivers for Arria 10 FPGA bitstream loading

[Chee, Tien Fong <tien.fong.chee@intel.com>]

On Thu, 2019-02-14 at 11:41 +0100, Marek Vasut wrote:
> On 2/14/19 7:44 AM, Chee, Tien Fong wrote:
> > 
> > On Wed, 2019-02-13 at 17:20 +0100, Marek Vasut wrote:
> > > 
> > > On 2/13/19 3:18 PM, tien.fong.chee at intel.com wrote:
> > > > 
> > > > 
> > > > From: Tien Fong Chee <tien.fong.chee@intel.com>
> > > > 
> > > > Add FPGA driver to support program FPGA with FPGA bitstream
> > > > loading
> > > > from
> > > > filesystem. The driver are designed based on generic firmware
> > > > loader
> > > > framework. The driver can handle FPGA program operation from
> > > > loading FPGA
> > > > bitstream in flash to memory and then to program FPGA.
> > > > 
> > > > Signed-off-by: Tien Fong Chee <tien.fong.chee@intel.com>
> > > > 
> > > > ---
> > > > 
> > > > changes for v8
> > > > - Added codes to discern bitstream type based on fpga node
> > > > name.
> > > > 
> > > > changes for v7
> > > > - Restructure the FPGA driver to support both peripheral
> > > > bitstream
> > > > and core
> > > >   bitstream bundled into FIT image.
> > > > - Support loadable property for core bitstream. User can set
> > > > loadable
> > > >   in DDR for better performance. This loading would be done in
> > > > one
> > > > large
> > > >   chunk instead of chunk by chunk loading with small memory
> > > > buffer.
> > > > ---
> > > >  arch/arm/dts/socfpga_arria10_socdk_sdmmc.dts       |  17 +
> > > >  .../include/mach/fpga_manager_arria10.h            |  39 +-
> > > >  drivers/fpga/socfpga_arria10.c                     | 467
> > > > ++++++++++++++++++++-
> > > >  3 files changed, 500 insertions(+), 23 deletions(-)
> > > > 
> > > > diff --git a/arch/arm/dts/socfpga_arria10_socdk_sdmmc.dts
> > > > b/arch/arm/dts/socfpga_arria10_socdk_sdmmc.dts
> > > > index 998d811..14f1967 100644
> > > > --- a/arch/arm/dts/socfpga_arria10_socdk_sdmmc.dts
> > > > +++ b/arch/arm/dts/socfpga_arria10_socdk_sdmmc.dts
[...]

> > > > - * FPGA Manager to program the FPGA. This is the interface
> > > > used by
> > > > FPGA driver.
> > > > - * Return 0 for sucess, non-zero for error.
> > > > - */
> > > > +char *get_fpga_filename(const void *fdt, int *len)
> > > > +{
> > > > +	char *fpga_filename = NULL;
> > > > +	int node_offset;
> > > > +
> > > > +	fdtdec_find_aliases_for_id(gd->fdt_blob, "fpga_mgr",
> > > > +				COMPAT_ALTERA_SOCFPGA_FPGA0,
> > > > +				&node_offset, 1);
> > > > +
> > > > +	ofnode fpgamgr_node = offset_to_ofnode(node_offset);
> > > > +
> > > > +	if (ofnode_valid(fpgamgr_node))
> > > > +		fpga_filename = (char
> > > > *)ofnode_read_string(fpgamgr_node,
> > > > +						"altr,bitstrea
> > > > m");
> > > > +
> > > > +
> > > Why is the cast needed ?
> > The return string would be eventually set to the char *filename in
> > common struct fpga_fsinfo. So, the cast here is to avoid the
> > warning
> > from compiler.
> I presume if the compiler generates a warning, it's for a reason.
> What
> warning is that ?
drivers/fpga/socfpga_arria10.c: In function 'get_fpga_filename':
drivers/fpga/socfpga_arria10.c:466:17: warning: assignment discards
'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
   fpga_filename = ofnode_read_string(fpgamgr_node,
> 

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