Re: [PATCH v3 4/6] DEV: CLK: add function to check the using clock name of driver.
From: Thierry Reding <hidden>
Date: 2018-11-26 15:26:43
Also in:
linux-arm-kernel, linux-gpio, linux-pwm, lkml
On Mon, Nov 26, 2018 at 12:21:18AM +0800, Hao Zhang wrote:
In some situation we want to check clock whether is we want and after the driver been probed use to change different clock source. Signed-off-by: Hao Zhang <redacted> --- drivers/clk/clk.c | 6 ++++++ include/linux/clk-provider.h | 1 + 2 files changed, 7 insertions(+)
This doesn't seem right. If you're going to change to to a different clock source anyway, why would you even want to know what it was set before that? Isn't that completely irrelevant? But if you really need this, perhaps a combination of clk_get() and clk_is_match() would be a better approach? Perhaps best to let Mike and Stephen share their feelings about this kind of API.
quoted hunk ↗ jump to hunk
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index d31055a..3d2c2cd 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c@@ -3466,6 +3466,12 @@ static int devm_clk_hw_match(struct device *dev, void *res, void *data) return hw == data; } +bool devm_clk_name_match(struct clk *clk, const char *string) +{ + return match_string(&clk->con_id, 1, string) == 0; +} +EXPORT_SYMBOL_GPL(devm_clk_name_match);
Also, there's nothing about this that would be device-managed, so the devm_ prefix on the function name is misleading.
quoted hunk ↗ jump to hunk
/** * devm_clk_unregister - resource managed clk_unregister() * @clk: clock to unregisterdiff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 08b1aa7..5cd2eed 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h@@ -764,6 +764,7 @@ struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw); int __must_check clk_hw_register(struct device *dev, struct clk_hw *hw); int __must_check devm_clk_hw_register(struct device *dev, struct clk_hw *hw); +bool devm_clk_name_match(struct clk *clk, const char *string); void clk_unregister(struct clk *clk); void devm_clk_unregister(struct device *dev, struct clk *clk);
You use this from clock consumers, so clk-provider.h is not the right place for it. Also, you'll want to add a dummy implementation for the case where CONFIG_COMMON_CLK is not set. Thierry