Bluetooth: hci_bcm: Mandate presence of shutdown and device wake GPIO

Commit 0395ffc1ee05 ("Bluetooth: hci_bcm: Add PM for BCM devices")
amended this driver to request a shutdown and device wake GPIO on probe,
but mandated that only one of them need to be present:

	/* Make sure at-least one of the GPIO is defined and that
	 * a name is specified for this instance
	 */
	if ((!dev->device_wakeup && !dev->shutdown) || !dev->name) {
		dev_err(&pdev->dev, "invalid platform data\n");
		return -EINVAL;
	}

However the same commit added a call to bcm_gpio_set_power() to the
->probe hook, which unconditionally accesses *both* GPIOs.  Luckily,
the resulting NULL pointer deref was never reported, suggesting there's
no machine where either GPIO is missing.

Commit 8a92056837fd ("Bluetooth: hci_bcm: Add (runtime)pm support to the
serdev driver") removed the check whether at least one of the GPIOs is
present without specifying a reason.

Because commit 62aaefa7d038 ("Bluetooth: hci_bcm: improve use of gpios
API") refactored the driver to use devm_gpiod_get_optional() instead of
devm_gpiod_get(), one is now tempted to believe that the driver doesn't
require *any* of the two GPIOs.

Which is wrong, the driver still requires both GPIOs to avoid a NULL
pointer deref.  To this end, establish the status quo ante and request
the GPIOs with devm_gpiod_get() again.  Bail out of ->probe if either
of them is missing.

Oddly enough, whereas bcm_gpio_set_power() accesses the device wake pin
unconditionally, bcm_suspend_device() and bcm_resume_device() do check
for its presence before accessing it.  Those checks are superfluous,
so remove them.

Cc: Frédéric Danis <[email protected]>
Cc: Loic Poulain <[email protected]>
Cc: Hans de Goede <[email protected]>
Cc: Uwe Kleine-König <[email protected]>
Cc: Linus Walleij <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Signed-off-by: Lukas Wunner <[email protected]>
Signed-off-by: Marcel Holtmann <[email protected]>

diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
index 1fc604a0d87005125c81236e554a961f983a3f72..7d059b35c63a8a0132ec32e15ae299bbd3bdab9f 100644 (file)
--- a/drivers/bluetooth/hci_bcm.c
+++ b/drivers/bluetooth/hci_bcm.c
@@ -572,11 +572,9 @@ static int bcm_suspend_device(struct device *dev)
        }
 
        /* Suspend the device */
-       if (bdev->device_wakeup) {
-               gpiod_set_value(bdev->device_wakeup, false);
-               bt_dev_dbg(bdev, "suspend, delaying 15 ms");
-               mdelay(15);
-       }
+       gpiod_set_value(bdev->device_wakeup, false);
+       bt_dev_dbg(bdev, "suspend, delaying 15 ms");
+       mdelay(15);
 
        return 0;
 }
@@ -587,11 +585,9 @@ static int bcm_resume_device(struct device *dev)
 
        bt_dev_dbg(bdev, "");
 
-       if (bdev->device_wakeup) {
-               gpiod_set_value(bdev->device_wakeup, true);
-               bt_dev_dbg(bdev, "resume, delaying 15 ms");
-               mdelay(15);
-       }
+       gpiod_set_value(bdev->device_wakeup, true);
+       bt_dev_dbg(bdev, "resume, delaying 15 ms");
+       mdelay(15);
 
        /* When this executes, the device has woken up already */
        if (bdev->is_suspended && bdev->hu) {
@@ -774,14 +770,12 @@ static int bcm_get_resources(struct bcm_device *dev)
 
        dev->clk = devm_clk_get(dev->dev, NULL);
 
-       dev->device_wakeup = devm_gpiod_get_optional(dev->dev,
-                                                    "device-wakeup",
-                                                    GPIOD_OUT_LOW);
+       dev->device_wakeup = devm_gpiod_get(dev->dev, "device-wakeup",
+                                           GPIOD_OUT_LOW);
        if (IS_ERR(dev->device_wakeup))
                return PTR_ERR(dev->device_wakeup);
 
-       dev->shutdown = devm_gpiod_get_optional(dev->dev, "shutdown",
-                                               GPIOD_OUT_LOW);
+       dev->shutdown = devm_gpiod_get(dev->dev, "shutdown", GPIOD_OUT_LOW);
        if (IS_ERR(dev->shutdown))
                return PTR_ERR(dev->shutdown);