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

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Date:	Wed, 18 Mar 2015 14:53:17 +0100
From:	Martin Fuzzey <mfuzzey@...keon.com>
To:	Mike Turquette <mturquette@...aro.org>, Jyri Sarha <jsarha@...com>
Cc:	linux-kernel@...r.kernel.org
Subject: [PATCH] clk: clk-gpio-gate: Fix active low

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>
---
 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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