clk: qcom: rcg2: expand frac table for mdss_pixel_clk_src

Recently, when testing 10-bit dsi C-PHY panel, clks are different
from the usual. (dsi0_phy_pll_out_dsiclk's parent is dsi0_pll_bit_clk
now (dsiclk_sel = 0)) And we failed to set dsiclk's children.

dsi_link_clk_set_rate_6g: Set clk rates: pclk=172992000, byteclk=108120000

byteclk was set first to 108120000, so the vco rate was set to
108120000 * 7 * 1 * 1 = 756840000. When we was trying to set
172992000 on mdss_pixel_clk_src later.

Since there was no matched ratio, we failed to set it. And dsiclk
divider ratio was set to 15:1 (wrong cached register value 0xf and
didn't update), we finally got 50455997, apparently wrong.

  dsi0vco_clk                1       1        0        756839941
     dsi0_pll_out_div_clk    1       1        0        756839941
        dsi0_pll_post_out_div_clk 0       0        0        216239983
        dsi0_pll_bit_clk     2       2        0        756839941
           dsi0_phy_pll_out_dsiclk 2       2        0        50455997
              disp_cc_mdss_pclk1_clk_src 1       1        0        50455997
           dsi0_pll_by_2_bit_clk 0       0        0        378419970
           dsi0_phy_pll_out_byteclk 2       2        0        108119991
              disp_cc_mdss_byte1_clk_src 2       2        0        108119991

Downstream clk_summary shows the mdss_pixel_clk_src support the
ratio(35:16)

 dsi0_phy_pll_out_dsiclk             2       2        0        378420000
     disp_cc_mdss_pclk1_clk_src       1       1        0        172992000
 dsi0_phy_pll_out_byteclk            2       2        0        108120000
     disp_cc_mdss_byte1_clk_src       2       2        0        108120000

After checking downstream source, 15:4 also seems to be supported,
add them two.

Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
Reviewed-by: Taniya Das <taniya.das@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260321095029.2259489-1-mitltlatltl@gmail.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c
index fc696b66ccda9f32483a3e48440cef44fddcde05..6064a0e17d5190e9d228688c04c0d4947876b4e6 100644 (file)
--- a/drivers/clk/qcom/clk-rcg2.c
+++ b/drivers/clk/qcom/clk-rcg2.c
@@ -1117,6 +1117,8 @@ static const struct frac_entry frac_table_pixel[] = {
        { 4, 9 },
        { 1, 1 },
        { 2, 3 },
+       { 16, 35},
+       { 4, 15},
        { }
 };