Re: [PATCH v42 3/6] clk: Provide OF helper to mark clocks as CRITICAL

From: Lee Jones
Date: Fri Feb 12 2016 - 03:03:10 EST


On Thu, 11 Feb 2016, Michael Turquette wrote:

> From: Lee Jones <lee.jones@xxxxxxxxxx>
>
> This call matches clocks which have been marked as critical in DT
> and sets the appropriate flag. These flags can then be used to
> mark the clock core flags appropriately prior to registration.
>
> Legacy bindings requiring this feature must add the clock-critical
> property to their binding descriptions, as it is not a part of
> common-clock binding.
>
> Cc: devicetree@xxxxxxxxxxxxxxx
> Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
> Signed-off-by: Michael Turquette <mturquette@xxxxxxxxxxxx>
> ---
> Changed in vWhatever:
> * Added kerneldoc
> * Moved to clk.c, removed static inline
> * s/of_clk_mark_if_critical/of_clk_detect_critical/

Looks like you didn't fold this change in.

Only the kerneldoc is correct.

> * s/critical-clock/clock-critical/
>
> drivers/clk/clk.c | 35 +++++++++++++++++++++++++++++++++++
> include/linux/clk-provider.h | 8 +++++++-
> 2 files changed, 42 insertions(+), 1 deletion(-)

Appart from the small aforementioned issue, the changes look good to
me.

> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 39f9527..5181a15 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -3202,6 +3202,41 @@ static int parent_ready(struct device_node *np)
> }
>
> /**
> + * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
> + * @np: Device node pointer associated with clock provider
> + * @index: clock index
> + * @flags: pointer to clk_core->flags
> + *
> + * Detects if the clock-critical property exists and, if so, sets the
> + * corresponding CLK_IS_CRITICAL flag.
> + *
> + * Do not use this function. It exists only for legacy Device Tree
> + * bindings, such as the one-clock-per-node style that are outdated.
> + * Those bindings typically put all clock data into .dts and the Linux
> + * driver has no clock data, thus making it impossible to set this flag
> + * correctly from the driver. Only those drivers may call
> + * of_clk_detect_critical from their setup functions.
> + *
> + * Return: error code or zero on success
> + */
> +int of_clk_mark_if_critical(struct device_node *np,
> + int index, unsigned long *flags)
> +{
> + struct property *prop;
> + const __be32 *cur;
> + uint32_t idx;
> +
> + if (!np || !flags)
> + return -EINVAL;
> +
> + of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
> + if (index == idx)
> + *flags |= CLK_IS_CRITICAL;
> +
> + return 0;
> +}
> +
> +/**
> * of_clk_init() - Scan and init clock providers from the DT
> * @matches: array of compatible values and init functions for providers.
> *
> diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
> index 1d986ea..d15d3cc 100644
> --- a/include/linux/clk-provider.h
> +++ b/include/linux/clk-provider.h
> @@ -705,7 +705,8 @@ int of_clk_get_parent_count(struct device_node *np);
> int of_clk_parent_fill(struct device_node *np, const char **parents,
> unsigned int size);
> const char *of_clk_get_parent_name(struct device_node *np, int index);
> -
> +int of_clk_mark_if_critical(struct device_node *np, int index,
> + unsigned long *flags);
> void of_clk_init(const struct of_device_id *matches);
>
> #else /* !CONFIG_OF */
> @@ -742,6 +743,11 @@ static inline const char *of_clk_get_parent_name(struct device_node *np,
> {
> return NULL;
> }
> +static inline int of_clk_mark_if_critical(struct device_node *np, int index,
> + unsigned long *flags)
> +{
> + return 0;
> +}
> static inline void of_clk_init(const struct of_device_id *matches) {}
> #endif /* CONFIG_OF */
>

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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