diff options
| author | Taniya Das <tdas@codeaurora.org> | 2022-02-27 20:55:35 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-08 15:23:47 +0300 |
| commit | 34dca60982e93e69ae442aa2d36ce61c9a3bb563 (patch) | |
| tree | da84d6d33c30393a369c6615178081f17873c448 /drivers/clk | |
| parent | 7a778371f9f2d8c8d6301b4207188a0ef9d9eb16 (diff) | |
| download | linux-34dca60982e93e69ae442aa2d36ce61c9a3bb563.tar.xz | |
clk: qcom: clk-rcg2: Update logic to calculate D value for RCG
[ Upstream commit 58922910add18583d5273c2edcdb9fd7bf4eca02 ]
The display pixel clock has a requirement on certain newer platforms to
support M/N as (2/3) and the final D value calculated results in
underflow errors.
As the current implementation does not check for D value is within
the accepted range for a given M & N value. Update the logic to
calculate the final D value based on the range.
Fixes: 99cbd064b059f ("clk: qcom: Support display RCG clocks")
Signed-off-by: Taniya Das <tdas@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220227175536.3131-1-tdas@codeaurora.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/clk')
| -rw-r--r-- | drivers/clk/qcom/clk-rcg2.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c index e1b1b426fae4..b831975a9606 100644 --- a/drivers/clk/qcom/clk-rcg2.c +++ b/drivers/clk/qcom/clk-rcg2.c @@ -264,7 +264,7 @@ static int clk_rcg2_determine_floor_rate(struct clk_hw *hw, static int __clk_rcg2_configure(struct clk_rcg2 *rcg, const struct freq_tbl *f) { - u32 cfg, mask; + u32 cfg, mask, d_val, not2d_val, n_minus_m; struct clk_hw *hw = &rcg->clkr.hw; int ret, index = qcom_find_src_index(hw, rcg->parent_map, f->src); @@ -283,8 +283,17 @@ static int __clk_rcg2_configure(struct clk_rcg2 *rcg, const struct freq_tbl *f) if (ret) return ret; + /* Calculate 2d value */ + d_val = f->n; + + n_minus_m = f->n - f->m; + n_minus_m *= 2; + + d_val = clamp_t(u32, d_val, f->m, n_minus_m); + not2d_val = ~d_val & mask; + ret = regmap_update_bits(rcg->clkr.regmap, - RCG_D_OFFSET(rcg), mask, ~f->n); + RCG_D_OFFSET(rcg), mask, not2d_val); if (ret) return ret; } |