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GPIO PL061: Adding Clk framework support

PATCH Superseded Viresh KUMAR 2 participants 3 messages Jun 22, 2010 GPIO

v2 of 4 Superseded Latest is v4 →

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Viresh KUMAR

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#0 lore raw

PATCH v2 1/1 GPIO PL061: Adding Clk framework support

From: Viresh KUMAR <[email protected]>

GPIO Clk is never enabled on Platforms, like: SPEAr, which are based upon clock framework and use PL061 driver. This patch adds support for Clk enabling and disabling as and when gpios are requested and freed.

modifications since V2:
- if clk_get returns -ENOENT, then work without clk enable/disable.

Signed-off-by Viresh Kumar <[email protected]>
---
 drivers/gpio/pl061.c |   47 ++++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 44 insertions(+), 3 deletions(-)
drivers/gpio/pl061.c +44 -3
index 105701a..b2a556b 100644
@@ -11,7 +11,10 @@
  *
  * Data sheet: ARM DDI 0190B, September 2000
  */
+
+#include <linux/clk.h>
 #include <linux/spinlock.h>
+#include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/list.h>

@@ -56,8 +59,31 @@ struct pl061_gpio {
 	void __iomem		*base;
 	unsigned		irq_base;
 	struct gpio_chip	gc;
+	struct clk		*clk;
 };
 
+static int pl061_request(struct gpio_chip *gc, unsigned offset)
+{
+	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
+	int ret;
+
+	if (offset >= gc->ngpio)
+		return -EINVAL;
+
+	if (chip->clk)
+		ret = clk_enable(chip->clk);
+
+	return ret
+}
+
+static void pl061_free(struct gpio_chip *gc, unsigned offset)
+{
+	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
+
+	if (chip->clk)
+		clk_disable(chip->clk);
+}
+
 static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
 {
 	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);

@@ -260,10 +286,22 @@ static int __init pl061_probe(struct amba_device *dev, struct amba_id *id)
 		goto release_region;
 	}
 
+	chip->clk = clk_get(&dev->dev, NULL);
+	if (IS_ERR(chip->clk)) {
+		ret = PTR_ERR(chip->clk);
+		/* clk Not present */
+		if (ret == -ENOENT)
+			chip->clk = NULL;
+		else
+			goto iounmap;
+	}
+
 	spin_lock_init(&chip->lock);
 	spin_lock_init(&chip->irq_lock);
 	INIT_LIST_HEAD(&chip->list);
 
+	chip->gc.request = pl061_request;
+	chip->gc.free = pl061_free;
 	chip->gc.direction_input = pl061_direction_input;
 	chip->gc.direction_output = pl061_direction_output;
 	chip->gc.get = pl061_get_value;

@@ -279,7 +317,7 @@ static int __init pl061_probe(struct amba_device *dev, struct amba_id *id)
 
 	ret = gpiochip_add(&chip->gc);
 	if (ret)
-		goto iounmap;
+		goto free_clk;
 
 	/*
 	 * irq_chip support

@@ -292,7 +330,7 @@ static int __init pl061_probe(struct amba_device *dev, struct amba_id *id)
 	irq = dev->irq[0];
 	if (irq < 0) {
 		ret = -ENODEV;
-		goto iounmap;
+		goto free_clk;
 	}
 	set_irq_chained_handler(irq, pl061_irq_handler);
 	if (!test_and_set_bit(irq, init_irq)) { /* list initialized? */

@@ -300,7 +338,7 @@ static int __init pl061_probe(struct amba_device *dev, struct amba_id *id)
 		if (chip_list == NULL) {
 			clear_bit(irq, init_irq);
 			ret = -ENOMEM;
-			goto iounmap;
+			goto free_clk;
 		}
 		INIT_LIST_HEAD(chip_list);
 		set_irq_data(irq, chip_list);

@@ -323,6 +361,9 @@ static int __init pl061_probe(struct amba_device *dev, struct amba_id *id)
 
 	return 0;
 
+free_clk:
+	if (chip->clk)
+		clk_put(chip->clk);
 iounmap:
 	iounmap(chip->base);
 release_region:
Signature · 1 line
1.6.0.2
#1 lore raw

PATCH v2 1/1 GPIO PL061: Adding Clk framework support

Review

Quoted 12 lines · Viresh KUMAR
(quoted diff) +12 -0
+static int pl061_request(struct gpio_chip *gc, unsigned offset)
+{
+ ? ? ? struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
+ ? ? ? int ret;
+
+ ? ? ? if (offset >= gc->ngpio)
+ ? ? ? ? ? ? ? return -EINVAL;
+
+ ? ? ? if (chip->clk)
+ ? ? ? ? ? ? ? ret = clk_enable(chip->clk);
+
+ ? ? ? return ret

Missing semicolon.

Also, returning uninitialized values when chip->clk is not set.

You can probably just not register these callbacks for the !chip->clk case.

Rabin

author
#2 lore raw

PATCH v2 1/1 GPIO PL061: Adding Clk framework support

Quoted 16 lines · Rabin Vincent

drivers/gpio/pl061.c struct pl061_gpio { · line 76

Quoted 12 lines · Viresh KUMAR
drivers/gpio/pl061.c +12 -0
+static int pl061_request(struct gpio_chip *gc, unsigned offset)
+{
+       struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
+       int ret;
+
+       if (offset >= gc->ngpio)
+               return -EINVAL;
+
+       if (chip->clk)
+               ret = clk_enable(chip->clk);
+
+       return ret

Also, returning uninitialized values when chip->clk is not set.

Quoted 3 lines

You can probably just not register these callbacks for the !chip->clk case.

Sorry. Will correct it.