clk: qcom: Allow constant ratio freq tables for rcg
authorJeffrey Hugo <jeffrey.l.hugo@gmail.com>
Thu, 31 Oct 2019 18:57:15 +0000 (11:57 -0700)
committerStephen Boyd <sboyd@kernel.org>
Thu, 7 Nov 2019 21:43:19 +0000 (13:43 -0800)
commitefd164b5520afd6fb2883b68e0d408a7de29c491
treee915653e4bb197023e57455cfa36d61a753577c2
parentba1d366de261981c0dd04fac44d2ce3a5eba2eaa
clk: qcom: Allow constant ratio freq tables for rcg

Some RCGs (the gfx_3d_src_clk in msm8998 for example) are basically just
some constant ratio from the input across the entire frequency range.  It
would be great if we could specify the frequency table as a single entry
constant ratio instead of a long list, ie:

{ .src = P_GPUPLL0_OUT_EVEN, .pre_div = 3 },
        { }

So, lets support that.

We need to fix a corner case in qcom_find_freq() where if the freq table
is non-null, but has no frequencies, we end up returning an "entry" before
the table array, which is bad.  Then, we need ignore the freq from the
table, and instead base everything on the requested freq.

Suggested-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Link: https://lkml.kernel.org/r/20191031185715.15504-1-jeffrey.l.hugo@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
drivers/clk/qcom/clk-rcg2.c
drivers/clk/qcom/common.c