lkml.org 
[lkml]   [2020]   [Jan]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.19 028/114] clk: qcom: Allow constant ratio freq tables for rcg
    Date
    From: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>

    [ Upstream commit efd164b5520afd6fb2883b68e0d408a7de29c491 ]

    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>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/clk/qcom/clk-rcg2.c | 2 ++
    drivers/clk/qcom/common.c | 3 +++
    2 files changed, 5 insertions(+)

    diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c
    index 52208d4165f4..51b2388d80ac 100644
    --- a/drivers/clk/qcom/clk-rcg2.c
    +++ b/drivers/clk/qcom/clk-rcg2.c
    @@ -206,6 +206,8 @@ static int _freq_tbl_determine_rate(struct clk_hw *hw, const struct freq_tbl *f,
    if (clk_flags & CLK_SET_RATE_PARENT) {
    rate = f->freq;
    if (f->pre_div) {
    + if (!rate)
    + rate = req->rate;
    rate /= 2;
    rate *= f->pre_div + 1;
    }
    diff --git a/drivers/clk/qcom/common.c b/drivers/clk/qcom/common.c
    index db9b2471ac40..bfb6d6065a90 100644
    --- a/drivers/clk/qcom/common.c
    +++ b/drivers/clk/qcom/common.c
    @@ -29,6 +29,9 @@ struct freq_tbl *qcom_find_freq(const struct freq_tbl *f, unsigned long rate)
    if (!f)
    return NULL;

    + if (!f->freq)
    + return f;
    +
    for (; f->freq; f++)
    if (rate <= f->freq)
    return f;
    --
    2.20.1


    \
     
     \ /
      Last update: 2020-01-02 23:56    [W:3.102 / U:2.956 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site