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Subject[PATCH v2] gpio/omap: add *remove* callback in platform_driver
Date
Add *remove* callback so that necessary cleanup operations are
performed when device is unregistered. The device is deleted
from the list and associated clock handle is released by
calling clk_put() and irq descriptor is released using the
irq_free_desc() api.

Signed-off-by: Tarun Kanti DebBarma <tarun.kanti@ti.com>
Reported-by: Paul Walmsley <paul@pwsan.com>
Reviewed-by: Jon Hunter <jon-hunter@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Cousson, Benoit <b-cousson@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
---
v2:
Baseline: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
Commit: 0d7614f09c1ebdbaa1599a5aba7593f147bf96ee (Linux 3.6-rc1)

(1) Use irq_free_descs() instead of irq_free_desc().
Besides, irq_free_desc() was using wrong parameter,
irq_base, instead of bank->irq.
(2) irq_free_descs() moved outside spin_lock/unlock_*()
in order to avoid exception warnings.

(3) pm_runtime_disable() added so that bind can happen successfully

Test Detail:
Step 1: Unbind gpio.5 device in order to invoke the *remove* callback.
#echo "omap_gpio.5" > sys/bus/platform/drivers/omap_gpio/unbind

Step 2: Bind gpio.5 device and confirm probe() for the device succeeds.
#echo "omap_gpio.5" > sys/bus/platform/drivers/omap_gpio/bind

Step 3: Execute read/write GPIO test case.

drivers/gpio/gpio-omap.c | 35 +++++++++++++++++++++++++++++++++++
1 files changed, 35 insertions(+), 0 deletions(-)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index e6efd77..50de875 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -1152,6 +1152,40 @@ static int __devinit omap_gpio_probe(struct platform_device *pdev)
return ret;
}

+/**
+ * omap_gpio_remove - cleanup a registered gpio device
+ * @pdev: pointer to current gpio platform device
+ *
+ * Called by driver framework whenever a gpio device is unregistered.
+ * GPIO is deleted from the list and associated clock handle freed.
+ */
+static int __devexit omap_gpio_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct gpio_bank *bank;
+ unsigned long flags;
+ int ret = -EINVAL;
+
+ list_for_each_entry(bank, &omap_gpio_list, node) {
+ spin_lock_irqsave(&bank->lock, flags);
+ if (bank->dev == dev) {
+ clk_put(bank->dbck);
+ list_del(&bank->node);
+ ret = 0;
+ spin_unlock_irqrestore(&bank->lock, flags);
+ break;
+ }
+ spin_unlock_irqrestore(&bank->lock, flags);
+ }
+
+ if (!ret) {
+ pm_runtime_disable(bank->dev);
+ irq_free_descs(bank->irq_base, bank->width);
+ }
+
+ return ret;
+}
+
#ifdef CONFIG_ARCH_OMAP2PLUS

#if defined(CONFIG_PM_RUNTIME)
@@ -1478,6 +1512,7 @@ MODULE_DEVICE_TABLE(of, omap_gpio_match);

static struct platform_driver omap_gpio_driver = {
.probe = omap_gpio_probe,
+ .remove = __devexit_p(omap_gpio_remove),
.driver = {
.name = "omap_gpio",
.pm = &gpio_pm_ops,
--
1.7.0.4


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