[PATCH 3/4] gpio-xilinx: Implement remove callback

From: Ricardo Ribalda Delgado
Date: Mon Dec 08 2014 - 10:08:12 EST


This way the driver can me unloaded.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>
---
drivers/gpio/gpio-xilinx.c | 52 +++++++++++++++++++++++++++++++++++++++-------
1 file changed, 45 insertions(+), 7 deletions(-)

diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
index 1199a31..f946d96 100644
--- a/drivers/gpio/gpio-xilinx.c
+++ b/drivers/gpio/gpio-xilinx.c
@@ -51,6 +51,11 @@ struct xgpio_instance {
u32 gpio_state;
u32 gpio_dir;
spinlock_t gpio_lock;
+ bool inited;
+};
+
+struct xgpio {
+ struct xgpio_instance port[2];
};

/**
@@ -173,7 +178,34 @@ static void xgpio_save_regs(struct of_mm_gpio_chip *mm_gc)
}

/**
+ * xgpio_remove - Remove method for the GPIO device.
+ * @pdev: pointer to the platform device
+ *
+ * This function remove gpiochips and frees all the allocated resources.
+ */
+static int xgpio_remove(struct platform_device *pdev)
+{
+ struct xgpio *xgpio = platform_get_drvdata(pdev);
+ int i;
+
+ for (i = 0; i < 2; i++) {
+ if (!xgpio->port[i].inited)
+ continue;
+ gpiochip_remove(&xgpio->port[i].mmchip.gc);
+
+ if (i == 1)
+ xgpio->port[i].mmchip.regs -= XGPIO_CHANNEL_OFFSET;
+
+ iounmap(xgpio->port[i].mmchip.regs);
+ kfree(xgpio->port[i].mmchip.gc.label);
+ }
+
+ return 0;
+}
+
+/**
* xgpio_of_probe - Probe method for the GPIO device.
+ * @pdev: pointer to the platform device
*
* This function probes the GPIO device in the device tree. It initializes the
* driver data structure. It returns 0, if the driver is bound to the GPIO
@@ -181,16 +213,22 @@ static void xgpio_save_regs(struct of_mm_gpio_chip *mm_gc)
*/
static int xgpio_probe(struct platform_device *pdev)
{
+ struct xgpio *xgpio;
struct xgpio_instance *chip;
int status = 0;
struct device_node *np = pdev->dev.of_node;
const u32 *tree_info;
u32 ngpio;

- chip = kzalloc(sizeof(*chip), GFP_KERNEL);
- if (!chip)
+ xgpio = (struct xgpio *) devm_kzalloc(&pdev->dev, sizeof(*xgpio),
+ GFP_KERNEL);
+ if (!xgpio)
return -ENOMEM;

+ platform_set_drvdata(pdev, xgpio);
+
+ chip = &xgpio->port[0];
+
/* Update GPIO state shadow register with default value */
of_property_read_u32(np, "xlnx,dout-default", &chip->gpio_state);

@@ -221,20 +259,18 @@ static int xgpio_probe(struct platform_device *pdev)
/* Call the OF gpio helper to setup and register the GPIO device */
status = of_mm_gpiochip_add(np, &chip->mmchip);
if (status) {
- kfree(chip);
pr_err("%s: error in probe function with status %d\n",
np->full_name, status);
return status;
}
+ chip->inited = true;

pr_info("XGpio: %s: registered, base is %d\n", np->full_name,
chip->mmchip.gc.base);

tree_info = of_get_property(np, "xlnx,is-dual", NULL);
if (tree_info && be32_to_cpup(tree_info)) {
- chip = kzalloc(sizeof(*chip), GFP_KERNEL);
- if (!chip)
- return -ENOMEM;
+ chip = &xgpio->port[1];

/* Update GPIO state shadow register with default value */
of_property_read_u32(np, "xlnx,dout-default-2",
@@ -267,7 +303,7 @@ static int xgpio_probe(struct platform_device *pdev)
/* Call the OF gpio helper to setup and register the GPIO dev */
status = of_mm_gpiochip_add(np, &chip->mmchip);
if (status) {
- kfree(chip);
+ xgpio_remove(pdev);
pr_err("%s: error in probe function with status %d\n",
np->full_name, status);
return status;
@@ -275,6 +311,7 @@ static int xgpio_probe(struct platform_device *pdev)

/* Add dual channel offset */
chip->mmchip.regs += XGPIO_CHANNEL_OFFSET;
+ chip->inited = true;

pr_info("XGpio: %s: dual channel registered, base is %d\n",
np->full_name, chip->mmchip.gc.base);
@@ -292,6 +329,7 @@ MODULE_DEVICE_TABLE(of, xgpio_of_match);

static struct platform_driver xgpio_plat_driver = {
.probe = xgpio_probe,
+ .remove = xgpio_remove,
.driver = {
.name = "gpio-xilinx",
.owner = THIS_MODULE,
--
2.1.3

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