linux-kernel - Re: [PATCH] clk: clk-gpio-gate: Fix active low

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Date:	Wed, 18 Mar 2015 16:52:14 +0200
From:	Jyri Sarha <jsarha@...com>
To:	Martin Fuzzey <mfuzzey@...keon.com>,
	Mike Turquette <mturquette@...aro.org>
CC:	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] clk: clk-gpio-gate: Fix active low

On 03/18/15 15:53, Martin Fuzzey wrote:
> The active low flag in the DT cell is currently ignored.
>
> This occurs because of_get_named_gpio_flags() does not apply the flags
> to the underlying struct gpio_desc so the test in clk_register_gpio_gate()
> was bogus.
>
> Note that this patch changes the internal kernel API for
> clk_register_gpio_gate() but there are currently no other users.
>
> Signed-off-by: Martin Fuzzey <mfuzzey@...keon.com>

Acked-by: Jyri Sarha <jsarha@...com>

> ---
>   drivers/clk/clk-gpio-gate.c  |   31 +++++++++++++++++--------------
>   include/linux/clk-provider.h |    2 +-
>   2 files changed, 18 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/clk/clk-gpio-gate.c b/drivers/clk/clk-gpio-gate.c
> index 08e4322..a71cabe 100644
> --- a/drivers/clk/clk-gpio-gate.c
> +++ b/drivers/clk/clk-gpio-gate.c
> @@ -65,10 +65,12 @@ EXPORT_SYMBOL_GPL(clk_gpio_gate_ops);
>    * @dev: device that is registering this clock
>    * @name: name of this clock
>    * @parent_name: name of this clock's parent
> - * @gpiod: gpio descriptor to gate this clock
> + * @gpio: gpio number to gate this clock
> + * @active_low: true if gpio should be set to 0 to enable clock
> + * @flags: clock flags
>    */
>   struct clk *clk_register_gpio_gate(struct device *dev, const char *name,
> -		const char *parent_name, struct gpio_desc *gpiod,
> +		const char *parent_name, unsigned gpio, bool active_low,
>   		unsigned long flags)
>   {
>   	struct clk_gpio *clk_gpio = NULL;
> @@ -77,20 +79,19 @@ struct clk *clk_register_gpio_gate(struct device *dev, const char *name,
>   	unsigned long gpio_flags;
>   	int err;
>
> -	if (gpiod_is_active_low(gpiod))
> -		gpio_flags = GPIOF_OUT_INIT_HIGH;
> +	if (active_low)
> +		gpio_flags = GPIOF_ACTIVE_LOW | GPIOF_OUT_INIT_HIGH;
>   	else
>   		gpio_flags = GPIOF_OUT_INIT_LOW;
>
>   	if (dev)
> -		err = devm_gpio_request_one(dev, desc_to_gpio(gpiod),
> -					    gpio_flags, name);
> +		err = devm_gpio_request_one(dev, gpio, gpio_flags, name);
>   	else
> -		err = gpio_request_one(desc_to_gpio(gpiod), gpio_flags, name);
> +		err = gpio_request_one(gpio, gpio_flags, name);
>
>   	if (err) {
>   		pr_err("%s: %s: Error requesting clock control gpio %u\n",
> -		       __func__, name, desc_to_gpio(gpiod));
> +		       __func__, name, gpio);
>   		return ERR_PTR(err);
>   	}
>
> @@ -111,7 +112,7 @@ struct clk *clk_register_gpio_gate(struct device *dev, const char *name,
>   	init.parent_names = (parent_name ? &parent_name : NULL);
>   	init.num_parents = (parent_name ? 1 : 0);
>
> -	clk_gpio->gpiod = gpiod;
> +	clk_gpio->gpiod = gpio_to_desc(gpio);
>   	clk_gpio->hw.init = &init;
>
>   	clk = clk_register(dev, &clk_gpio->hw);
> @@ -123,7 +124,8 @@ struct clk *clk_register_gpio_gate(struct device *dev, const char *name,
>   		kfree(clk_gpio);
>
>   clk_register_gpio_gate_err:
> -	gpiod_put(gpiod);
> +	if (!dev)
> +		gpio_free(gpio);
>
>   	return clk;
>   }
> @@ -149,8 +151,8 @@ static struct clk *of_clk_gpio_gate_delayed_register_get(
>   	struct clk *clk;
>   	const char *clk_name = data->node->name;
>   	const char *parent_name;
> -	struct gpio_desc *gpiod;
>   	int gpio;
> +	enum of_gpio_flags of_flags;
>
>   	mutex_lock(&data->lock);
>
> @@ -159,7 +161,8 @@ static struct clk *of_clk_gpio_gate_delayed_register_get(
>   		return data->clk;
>   	}
>
> -	gpio = of_get_named_gpio_flags(data->node, "enable-gpios", 0, NULL);
> +	gpio = of_get_named_gpio_flags(data->node, "enable-gpios", 0,
> +						&of_flags);
>   	if (gpio < 0) {
>   		mutex_unlock(&data->lock);
>   		if (gpio != -EPROBE_DEFER)
> @@ -167,11 +170,11 @@ static struct clk *of_clk_gpio_gate_delayed_register_get(
>   			       __func__, clk_name);
>   		return ERR_PTR(gpio);
>   	}
> -	gpiod = gpio_to_desc(gpio);
>
>   	parent_name = of_clk_get_parent_name(data->node, 0);
>
> -	clk = clk_register_gpio_gate(NULL, clk_name, parent_name, gpiod, 0);
> +	clk = clk_register_gpio_gate(NULL, clk_name, parent_name, gpio,
> +					of_flags & OF_GPIO_ACTIVE_LOW, 0);
>   	if (IS_ERR(clk)) {
>   		mutex_unlock(&data->lock);
>   		return clk;
> diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
> index d936409..6f514d5 100644
> --- a/include/linux/clk-provider.h
> +++ b/include/linux/clk-provider.h
> @@ -515,7 +515,7 @@ struct clk_gpio {
>
>   extern const struct clk_ops clk_gpio_gate_ops;
>   struct clk *clk_register_gpio_gate(struct device *dev, const char *name,
> -		const char *parent_name, struct gpio_desc *gpio,
> +		const char *parent_name, unsigned gpio, bool active_low,
>   		unsigned long flags);
>
>   void of_gpio_clk_gate_setup(struct device_node *node);
>

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