Messages in this thread | | | Date | Fri, 27 Jan 2023 00:51:51 +0200 | Subject | Re: [PATCH v4 7/7] clk: qcom: add the driver for the MSM8996 APCS clocks | From | Dmitry Baryshkov <> |
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On 25/01/2023 23:38, Stephen Boyd wrote: > Quoting Dmitry Baryshkov (2023-01-18 05:22:54) >> diff --git a/drivers/clk/qcom/apcs-msm8996.c b/drivers/clk/qcom/apcs-msm8996.c >> new file mode 100644 >> index 000000000000..7e46ea8ed444 >> --- /dev/null >> +++ b/drivers/clk/qcom/apcs-msm8996.c >> @@ -0,0 +1,76 @@ > [...] >> + >> +static int qcom_apcs_msm8996_clk_probe(struct platform_device *pdev) >> +{ >> + struct device *dev = &pdev->dev; >> + struct device *parent = dev->parent; >> + struct regmap *regmap; >> + struct clk_hw *hw; >> + unsigned int val; >> + int ret = -ENODEV; >> + >> + regmap = dev_get_regmap(parent, NULL); >> + if (!regmap) { >> + dev_err(dev, "failed to get regmap: %d\n", ret); >> + return ret; >> + } >> + >> + regmap_read(regmap, APCS_AUX_OFFSET, &val); >> + regmap_update_bits(regmap, APCS_AUX_OFFSET, APCS_AUX_DIV_MASK, >> + FIELD_PREP(APCS_AUX_DIV_MASK, APCS_AUX_DIV_2)); >> + >> + /* Hardware mandated delay */ > > Delay for what? Setting the divider? What if the register value didn't > change at all? Can you skip the delay in that case?
Ack, I'll expand the comment.
> >> + udelay(5); >> + >> + /* >> + * Register the clock as fixed rate instead of being a child of gpll0 >> + * to let the driver register probe as early as possible. > > The function doesn't block or return EPROBE_DEFER if the clk is orphaned > when registered. Why is this necessary? Are you getting defered by the > fw_devlink logic thinking it needs to defer probe of this driver until > gpll0 provider probes? We should fix fw_devlink to not do that. Maybe if > the node is a clk provider (#clock-cells exists) then we don't wait for > clocks property to be provided, because the clk core already handles > that itself.
Letting clock-controllers probe was my idea for the patch, but it was delayed again by Saravana, see [1], [2]
[1] https://lore.kernel.org/all/20230118091122.2205452-1-dmitry.baryshkov@linaro.org/
[2] https://lore.kernel.org/all/CAGETcx8Xy5OzsbW3123esxsbQJq-SqDkP1S5g2mmwzoCz4shtQ@mail.gmail.com/
> >> + */ >> + hw = devm_clk_hw_register_fixed_rate(dev, "sys_apcs_aux", NULL, 0, 300000000);
-- With best wishes Dmitry
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