Re: [PATCH v2] clk: tegra: Add BPMP clock driver

[Stephen Boyd <sboyd@codeaurora.org>]

On 02/06, Thierry Reding wrote:
> On Fri, Feb 03, 2017 at 12:43:02PM -0800, Stephen Boyd wrote:
> > On 01/25, Thierry Reding wrote:
> > > On Thu, Nov 17, 2016 at 04:47:31PM +0100, Thierry Reding wrote:
> > > > From: Thierry Reding <treding@nvidia.com>
> > > > 
> > > > This driver uses the services provided by the BPMP firmware driver to
> > > > implement a clock driver based on the MRQ_CLK request. This part of the
> > > > BPMP ABI provides a means to enumerate and control clocks and should
> > > > allow the driver to work on any chip that supports this ABI.
> > > > 
> > > > Signed-off-by: Thierry Reding <treding@nvidia.com>
> > > > ---
> > > > Changes in v2:
> > > > - rename ->prepare() and ->unprepare() implementations for consistency
> > > > - implement ->is_prepared() instead of ->is_enabled() to avoid the need
> > > >   for atomic operations
> > > > - rename tegra_bpmp_clk_message.clk member to id
> > > > - remove a double semi-colon and a stray ampersand
> > > > - drop extra check for validity of parent index, the core does it
> > > >   already
> > > > - make struct tegra_bpmp carry an array of struct tegra_bpmp_clk instead
> > > >   of struct clk_hw to simplify some driver code
> > > > - zero out struct clk_init_data to avoid potentially uninitialized data
> > > > - use devm_clk_hw_register() instead of clk_register() because we never
> > > >   need the opaque struct clk cookie
> > > > - rearrange functions so that they appear in the order specified by
> > > >   struct clk_ops
> > > > 
> > > >  drivers/clk/tegra/Kconfig    |   4 +
> > > >  drivers/clk/tegra/Makefile   |   1 +
> > > >  drivers/clk/tegra/clk-bpmp.c | 620 +++++++++++++++++++++++++++++++++++++++++++
> > > >  3 files changed, 625 insertions(+)
> > > >  create mode 100644 drivers/clk/tegra/clk-bpmp.c
> > > 
> > > Stephen, Mike,
> > > 
> > > we missed the last merge window with this, but it would be nice to get
> > > it in this time. Any more comments?
> > > 
> > 
> > Don't think so. Shall I merge it into clk-next?
> 
> Yeah, let me know if you do, then I can drop it from the Tegra tree.

Ok. I've applied it to clk-next now.

> 
> > Sadly it's not easy to test compile this single driver on the
> > commandline. Grumble.
> 
> Any way I could help with that? I did put this into the Tegra tree a
> while ago after not getting any further responses to at least get it
> some broader build coverage.
> 
> I personally use a set of scripts to make sure the proper drivers are
> compiled. If you can provide information about what you use, perhaps I
> can work with you to make this easier for you.

Ideally I'd like to compile the driver with

make drivers/clk/tegra/clk-bmpm.o

and have that just work. To do so, I have to make sure my config
has the right settings, which is the annoying part. If it wasn't
one-off APIs with #ifdefs to make things compile out when configs
aren't set it would work better.

Similar problems happen for I2C drivers. I should probably just
put the work into making a script figure out the right config to
compile a file or something. If you have a good solution here it
would be great if I could incorporate it into my flow.

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