This way we do not need to transverse the device tree manually and we
support hot plugged devices.
Also Implement remove callback so the driver can be unloaded
Signed-off-by: Ricardo Ribalda Delgado <ricardo.riba...@gmail.com>
---
v4: Add missing module_exit
drivers/gpio/gpio-xilinx.c | 83 ++++++++++++++++++++++++++++++++++++----------
1 file changed, 66 insertions(+), 17 deletions(-)
diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
index e668ec4..c7ed92b 100644
--- a/drivers/gpio/gpio-xilinx.c
+++ b/drivers/gpio/gpio-xilinx.c
@@ -44,12 +44,18 @@
* gpio_state: GPIO state shadow register
* gpio_dir: GPIO direction shadow register
* gpio_lock: Lock used for synchronization
+ * inited: True if the port has been inited
*/
struct xgpio_instance {
struct of_mm_gpio_chip mmchip;
u32 gpio_state;
u32 gpio_dir;
spinlock_t gpio_lock;
+ bool inited;
+};
+
+struct xgpio {
+ struct xgpio_instance port[2];
};
/**
@@ -172,24 +178,56 @@ 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.
- * @np: pointer to device tree node
+ * @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
* device, or a negative value if there is an error.
*/
-static int xgpio_of_probe(struct device_node *np)
+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 = 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);
@@ -209,6 +247,7 @@ static int xgpio_of_probe(struct device_node *np)
spin_lock_init(&chip->gpio_lock);
+ chip->mmchip.gc.dev = &pdev->dev;
chip->mmchip.gc.direction_input = xgpio_dir_in;
chip->mmchip.gc.direction_output = xgpio_dir_out;
chip->mmchip.gc.get = xgpio_get;
@@ -219,20 +258,18 @@ static int xgpio_of_probe(struct device_node *np)
/* 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",
@@ -254,6 +291,7 @@ static int xgpio_of_probe(struct device_node *np)
spin_lock_init(&chip->gpio_lock);
+ chip->mmchip.gc.dev = &pdev->dev;
chip->mmchip.gc.direction_input = xgpio_dir_in;
chip->mmchip.gc.direction_output = xgpio_dir_out;
chip->mmchip.gc.get = xgpio_get;
@@ -264,7 +302,7 @@ static int xgpio_of_probe(struct device_node *np)
/* 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;
@@ -272,6 +310,7 @@ static int xgpio_of_probe(struct device_node *np)
/* 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);
@@ -285,19 +324,29 @@ static const struct of_device_id xgpio_of_match[] = {
{ /* end of list */ },
};
-static int __init xgpio_init(void)
-{
- struct device_node *np;
+MODULE_DEVICE_TABLE(of, xgpio_of_match);
- for_each_matching_node(np, xgpio_of_match)
- xgpio_of_probe(np);
+static struct platform_driver xgpio_plat_driver = {
+ .probe = xgpio_probe,
+ .remove = xgpio_remove,
+ .driver = {
+ .name = "gpio-xilinx",
+ .of_match_table = xgpio_of_match,
+ },
+};
- return 0;
+static int __init xgpio_init(void)
+{
+ return platform_driver_register(&xgpio_plat_driver);
}
-/* Make sure we get initialized before anyone else tries to use us */
subsys_initcall(xgpio_init);
-/* No exit call at the moment as we cannot unregister of GPIO chips */
+
+static void __exit xgpio_exit(void)
+{
+ platform_driver_unregister(&xgpio_plat_driver);
+}
+module_exit(xgpio_exit);
MODULE_AUTHOR("Xilinx, Inc.");
MODULE_DESCRIPTION("Xilinx GPIO driver");
--
2.1.3
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