| Message ID | 20241028-alpha-mode-cleanup-v2-1-9bc6d712bd76@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | clk: qcom: remove superfluous alpha settings from PLL configs | expand |
On Mon, Oct 28, 2024 at 07:48:15PM +0100, Gabor Juhos wrote: > Since neither 'alpha' nor 'alpha_hi' is defined in the configuration, > those will be initialized with zero values implicitly. By using zero > alpha values, the output rate of the PLL will be the same whether > alpha mode is enabled or not. > > Remove the superfluous initialization of the 'alpha_en_mask' member > to make it clear that enabling alpha mode is not required to get the > desired output rate. > > Despite that enabling alpha mode is not needed for the initial > configuration, the set_rate() op might require that it is enabled > already. In this particular case however, the > clk_alpha_pll_stromer_set_rate() function will get reset the > ALPHA_EN bit when the PLL's rate changes, so dropping 'alpha_en_mask' > is safe. > > No functional changes, the initial rate of the PLL is the same both > before and after the patch. > > Tested on TP-Link Archer AX55 v1 (IPQ5018). > > Signed-off-by: Gabor Juhos <j4g8y7@gmail.com> > --- > Changes in v2: > - extend the commit message to indicate that dropping 'alpha_en_mask' is safe > - Link to v1: https://lore.kernel.org/r/20241021-alpha-mode-cleanup-v1-1-55df8ed73645@gmail.com > --- > drivers/clk/qcom/apss-ipq-pll.c | 1 - > 1 file changed, 1 deletion(-) > Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
diff --git a/drivers/clk/qcom/apss-ipq-pll.c b/drivers/clk/qcom/apss-ipq-pll.c index e8632db2c542806e9527a22b54fe169e3e398a7a..dec2a5019cc77bf60142a86453883e336afc860f 100644 --- a/drivers/clk/qcom/apss-ipq-pll.c +++ b/drivers/clk/qcom/apss-ipq-pll.c @@ -73,7 +73,6 @@ static const struct alpha_pll_config ipq5018_pll_config = { .main_output_mask = BIT(0), .aux_output_mask = BIT(1), .early_output_mask = BIT(3), - .alpha_en_mask = BIT(24), .status_val = 0x3, .status_mask = GENMASK(10, 8), .lock_det = BIT(2),
Since neither 'alpha' nor 'alpha_hi' is defined in the configuration, those will be initialized with zero values implicitly. By using zero alpha values, the output rate of the PLL will be the same whether alpha mode is enabled or not. Remove the superfluous initialization of the 'alpha_en_mask' member to make it clear that enabling alpha mode is not required to get the desired output rate. Despite that enabling alpha mode is not needed for the initial configuration, the set_rate() op might require that it is enabled already. In this particular case however, the clk_alpha_pll_stromer_set_rate() function will get reset the ALPHA_EN bit when the PLL's rate changes, so dropping 'alpha_en_mask' is safe. No functional changes, the initial rate of the PLL is the same both before and after the patch. Tested on TP-Link Archer AX55 v1 (IPQ5018). Signed-off-by: Gabor Juhos <j4g8y7@gmail.com> --- Changes in v2: - extend the commit message to indicate that dropping 'alpha_en_mask' is safe - Link to v1: https://lore.kernel.org/r/20241021-alpha-mode-cleanup-v1-1-55df8ed73645@gmail.com --- drivers/clk/qcom/apss-ipq-pll.c | 1 - 1 file changed, 1 deletion(-)