Subject: Re: [U-Boot] [PATCH v4 07/13] dm: clk: Define clk_get_parent() for clk operations
-----Original Message----- From: Lukasz Majewski [mailto:lukma@denx.de] Sent: 2019年5月17日 6:11 To: Stefano Babic sbabic@denx.de; Fabio Estevam festevam@gmail.com; Marek Vasut marex@denx.de; Simon Glass sjg@chromium.org; Tom Rini trini@konsulko.com; u-boot@lists.denx.de; Jagan Teki jagan@amarulasolutions.com; Peng Fan peng.fan@nxp.com; Marcel Ziswiler
Adam Ford aford173@gmail.com Cc: Lukasz Majewski lukma@denx.de; Neil Armstrong narmstrong@baylibre.com; Philipp Tomsich philipp.tomsich@theobroma-systems.com; Andreas Dannenberg dannenberg@ti.com; Fabrice Gasnier fabrice.gasnier@st.com; Liviu Dudau Liviu.Dudau@foss.arm.com Subject: [PATCH v4 07/13] dm: clk: Define clk_get_parent() for clk operations
This commit adds the clk_get_parent() function, which is responsible for getting the parent's struct clock pointer.
U-boot's DM support for getting parent is different (the parent relationship is in udevice) than the one in common clock framework (CCF) in Linux. To obtain the pointer to struct clk of parent the pdev->driver_data field is read.
Signed-off-by: Lukasz Majewski lukma@denx.de
Changes in v4: None Changes in v3:
- New patch
drivers/clk/clk-uclass.c | 15 +++++++++++++++ include/clk.h | 9 +++++++++ 2 files changed, 24 insertions(+)
diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c index 79b3b0494c..1a726dafaa 100644 --- a/drivers/clk/clk-uclass.c +++ b/drivers/clk/clk-uclass.c @@ -379,6 +379,21 @@ ulong clk_get_rate(struct clk *clk) return ops->get_rate(clk); }
+struct clk *clk_get_parent(struct clk *clk) {
- struct udevice *pdev;
- struct clk *pclk;
- debug("%s(clk=%p)\n", __func__, clk);
- pdev = dev_get_parent(clk->dev);
- pclk = (struct clk *)dev_get_driver_data(pdev);
This has a trick is that force driver_data to struct clk *, and this requires all clk wrappers needs take clk as the first element in the wrapper structure. So better add a comment here. Then it is fine to me, and
Sorry, drop my upper comments. The code is correct. So Reviewed-by: Peng Fan peng.fan@nxp.com
Reviewed-by: Peng Fan peng.fan@nxp.com
- if (!pclk)
return ERR_PTR(-ENODEV);- return pclk;
+}
ulong clk_set_rate(struct clk *clk, ulong rate) { const struct clk_ops *ops = clk_dev_ops(clk->dev); diff --git a/include/clk.h b/include/clk.h index 89dc64bfaf..0873b1e507 100644 --- a/include/clk.h +++ b/include/clk.h @@ -259,6 +259,15 @@ int clk_free(struct clk *clk); ulong clk_get_rate(struct clk *clk);
/**
- clk_get_parent() - Get current clock's parent.
- @clk: A clock struct that was previously successfully requested by
clk_request/get_by_*().
- @return pointer to parent's struct clk, or error code passed as
+pointer */ struct clk *clk_get_parent(struct clk *clk);
+/**
- clk_set_rate() - Set current clock rate.
- @clk: A clock struct that was previously successfully requested by
-- 2.11.0
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