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author | Archit Taneja <architt@codeaurora.org> | 2016-02-28 15:37:17 +0530 |
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committer | Stephen Boyd <sboyd@codeaurora.org> | 2016-02-29 12:57:06 -0800 |
commit | 811a498e5e9ab802cbd23a8ef9c844ec92450fa4 (patch) | |
tree | b869f7a6bfd55c6f85e18347af59e9feb2fe000b | |
parent | d3622b5885dc424cfb5e27ff7a3c79d942b2acb4 (diff) | |
download | op-kernel-dev-811a498e5e9ab802cbd23a8ef9c844ec92450fa4.zip op-kernel-dev-811a498e5e9ab802cbd23a8ef9c844ec92450fa4.tar.gz |
clk: qcom: Fix pre-divider usage for pixel RCG
The clk_rcg_pixel_set_rate clk_op sets up the pre-divider by reading
its current value from the NS register.
Using the pre-divider wasn't really intended when creating these ops.
The pixel RCG was only intended to achieve fractional multiplication
provided in the pixel_table array. Leaving the pre-divider to the
existing register value results in a wrong pixel clock when the
bootloader sets up the display. This was left unidentified because
the IFC6410 Plus board on which this was verified didn't have a
bootloader that configured the display.
Don't set the RCG pre-divider in freq_tbl to the existing NS register
value. Force it to 1 and only use the M/N counter to achieve the desired
fractional multiplication.
Cc: Vinay Simha <vinaysimha@inforcecomputing.com>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
-rw-r--r-- | drivers/clk/qcom/clk-rcg.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/clk/qcom/clk-rcg.c b/drivers/clk/qcom/clk-rcg.c index bfbb28f..67ce7c1 100644 --- a/drivers/clk/qcom/clk-rcg.c +++ b/drivers/clk/qcom/clk-rcg.c @@ -638,7 +638,6 @@ static int clk_rcg_pixel_set_rate(struct clk_hw *hw, unsigned long rate, return ret; src = ns_to_src(&rcg->s, ns); - f.pre_div = ns_to_pre_div(&rcg->p, ns) + 1; for (i = 0; i < num_parents; i++) { if (src == rcg->s.parent_map[i].cfg) { @@ -647,6 +646,9 @@ static int clk_rcg_pixel_set_rate(struct clk_hw *hw, unsigned long rate, } } + /* bypass the pre divider */ + f.pre_div = 1; + /* let us find appropriate m/n values for this */ for (; frac->num; frac++) { request = (rate * frac->den) / frac->num; |