Thread (4 messages) 4 messages, 4 authors, 2017-01-24

[PATCHv3 2/2] gpio: xilinx: Add clock support

From: Shubhrajyoti Datta <hidden>
Date: 2016-11-10 05:56:05
Also in: linux-gpio
Subsystem: gpio subsystem, the rest, xilinx gpio driver · Maintainers: Linus Walleij, Bartosz Golaszewski, Linus Torvalds, Shubhrajyoti Datta

Add basic clock support for xilinx gpio.

Signed-off-by: Shubhrajyoti Datta <redacted>
---
v2 :
no change
v3:
Add clock name
Remove some debug messages

 drivers/gpio/gpio-xilinx.c |   20 ++++++++++++++++++++
 1 files changed, 20 insertions(+), 0 deletions(-)
diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
index 14b2a62..3385a0a 100644
--- a/drivers/gpio/gpio-xilinx.c
+++ b/drivers/gpio/gpio-xilinx.c
@@ -13,6 +13,7 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/clk.h>
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/module.h>
@@ -45,6 +46,7 @@
  * @gpio_state: GPIO state shadow register
  * @gpio_dir: GPIO direction shadow register
  * @gpio_lock: Lock used for synchronization
+ * @clk: Clock resource for this controller
  */
 struct xgpio_instance {
 	struct of_mm_gpio_chip mmchip;
@@ -52,6 +54,7 @@ struct xgpio_instance {
 	u32 gpio_state[2];
 	u32 gpio_dir[2];
 	spinlock_t gpio_lock[2];
+	struct clk *clk;
 };
 
 static inline int xgpio_index(struct xgpio_instance *chip, int gpio)
@@ -282,6 +285,7 @@ static int xgpio_remove(struct platform_device *pdev)
 	struct xgpio_instance *chip = platform_get_drvdata(pdev);
 
 	of_mm_gpiochip_remove(&chip->mmchip);
+	clk_disable_unprepare(chip->clk);
 
 	return 0;
 }
@@ -307,6 +311,21 @@ static int xgpio_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, chip);
 
+	/* Retrieve GPIO clock */
+	chip->clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
+	if (IS_ERR(chip->clk)) {
+		if (PTR_ERR(chip->clk) == -ENOENT)
+			chip->clk = NULL;
+		else
+			return PTR_ERR(chip->clk);
+	}
+
+	status = clk_prepare_enable(chip->clk);
+	if (status) {
+		dev_err(&pdev->dev, "Unable to enable clock.\n");
+		return status;
+	}
+
 	/* Update GPIO state shadow register with default value */
 	of_property_read_u32(np, "xlnx,dout-default", &chip->gpio_state[0]);
 
@@ -362,6 +381,7 @@ static int xgpio_probe(struct platform_device *pdev)
 	if (status) {
 		pr_err("%s: error in probe function with status %d\n",
 		       np->full_name, status);
+		clk_disable_unprepare(chip->clk);
 		return status;
 	}
 
-- 
1.7.1
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