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Bluetooth: btbcm: Obtain and handle reset GPIO

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Obtain and drive the optional reset GPIO line if this is
not hardwired in the platform. This is needed on the
Samsung GT-I9070 mobile phone.

The invers of power is used, this should be OK to apply
simultaneously as the power signal according to
figures 47-51 on pages 159-161 in the BCM4330 datasheet.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
Linus Walleij 2021-03-05 19:37:36 +01:00 committed by Marcel Holtmann
parent 7820ee1c47
commit 2f40796671
1 changed files with 17 additions and 0 deletions
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17
drivers/bluetooth/hci_bcm.c
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@ -68,6 +68,8 @@ struct bcm_device_data {
* deassert = Bluetooth device may sleep when sleep criteria are met
* @shutdown: BT_REG_ON pin,
* power up or power down Bluetooth device internal regulators
* @reset: BT_RST_N pin,
* active low resets the Bluetooth logic core
* @set_device_wakeup: callback to toggle BT_WAKE pin
* either by accessing @device_wakeup or by calling @btlp
* @set_shutdown: callback to toggle BT_REG_ON pin
@ -101,6 +103,7 @@ struct bcm_device {
const char *name;
struct gpio_desc *device_wakeup;
struct gpio_desc *shutdown;
struct gpio_desc *reset;
int (*set_device_wakeup)(struct bcm_device *, bool);
int (*set_shutdown)(struct bcm_device *, bool);
#ifdef CONFIG_ACPI
@ -985,6 +988,15 @@ static int bcm_gpio_set_device_wakeup(struct bcm_device *dev, bool awake)
static int bcm_gpio_set_shutdown(struct bcm_device *dev, bool powered)
{
gpiod_set_value_cansleep(dev->shutdown, powered);
if (dev->reset)
/*
* The reset line is asserted on powerdown and deasserted
* on poweron so the inverse of powered is used. Notice
* that the GPIO line BT_RST_N needs to be specified as
* active low in the device tree or similar system
* description.
*/
gpiod_set_value_cansleep(dev->reset, !powered);
return 0;
}
@ -1050,6 +1062,11 @@ static int bcm_get_resources(struct bcm_device *dev)
if (IS_ERR(dev->shutdown))
return PTR_ERR(dev->shutdown);
dev->reset = devm_gpiod_get_optional(dev->dev, "reset",
GPIOD_OUT_LOW);
if (IS_ERR(dev->reset))
return PTR_ERR(dev->reset);
dev->set_device_wakeup = bcm_gpio_set_device_wakeup;
dev->set_shutdown = bcm_gpio_set_shutdown;