Retrieve "shutdown" and "device_wakeup" GPIOs from ACPI.
Set device off during platform device enumeration.
Set device on only when attached.
As driver can be unbound we need to check if the bcm_device still exists
before calling GPIO's functions, this is protected using device_list_lock.
Signed-off-by: Frederic Danis <frederic.danis@xxxxxxxxxxxxxxx>
---
drivers/bluetooth/hci_bcm.c | 216 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 214 insertions(+), 2 deletions(-)
diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
index 23523e1..6ac6636 100644
--- a/drivers/bluetooth/hci_bcm.c
+++ b/drivers/bluetooth/hci_bcm.c
@@ -25,6 +25,12 @@
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/firmware.h>
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/gpio/consumer.h>
+#include <linux/tty.h>
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
@@ -32,11 +38,30 @@
#include "btbcm.h"
#include "hci_uart.h"
+struct bcm_device {
+ struct list_head list;
+
+ struct platform_device *pdev;
+
+ const char *name;
+ struct gpio_desc *device_wakeup;
+ struct gpio_desc *shutdown;
+
+ struct clk *clk;
+ bool clk_enabled;
+};
+
struct bcm_data {
- struct sk_buff *rx_skb;
- struct sk_buff_head txq;
+ struct sk_buff *rx_skb;
+ struct sk_buff_head txq;
+
+ struct bcm_device *dev;
};
+/* List of BCM BT UART devices */
+static DEFINE_SPINLOCK(bcm_device_list_lock);
+static LIST_HEAD(bcm_device_list);
+
static int bcm_set_baudrate(struct hci_uart *hu, unsigned int speed)
{
struct hci_dev *hdev = hu->hdev;
@@ -86,9 +111,41 @@ static int bcm_set_baudrate(struct hci_uart *hu, unsigned int speed)
return 0;
}
+/* bcm_device_exists should be protected by bcm_device_list_lock */
+static bool bcm_device_exists(struct bcm_device *device)
+{
+ struct list_head *p;
+
+ list_for_each(p, &bcm_device_list) {
+ struct bcm_device *dev = list_entry(p, struct bcm_device, list);
+
+ if (device == dev)
+ return true;
+ }
+
+ return false;
+}
+
+static int bcm_gpio_set_power(struct bcm_device *dev, bool powered)
+{
+ if (powered && !IS_ERR(dev->clk) && !dev->clk_enabled)
+ clk_enable(dev->clk);
+
+ gpiod_set_value_cansleep(dev->shutdown, powered);
+ gpiod_set_value_cansleep(dev->device_wakeup, powered);
+
+ if (!powered && !IS_ERR(dev->clk) && dev->clk_enabled)
+ clk_disable(dev->clk);
+
+ dev->clk_enabled = powered;
+
+ return 0;
+}
+
static int bcm_open(struct hci_uart *hu)
{
struct bcm_data *bcm;
+ struct list_head *p;
BT_DBG("hu %p", hu);
@@ -99,6 +156,26 @@ static int bcm_open(struct hci_uart *hu)
skb_queue_head_init(&bcm->txq);
hu->priv = bcm;
+
+ spin_lock(&bcm_device_list_lock);
+ list_for_each(p, &bcm_device_list) {
+ struct bcm_device *dev = list_entry(p, struct bcm_device, list);
+
+ /* Retrieve saved bcm_device based on parent of the
+ * platform device (saved during device probe) and
+ * parent of tty device used by hci_uart
+ */
+ if (hu->tty->dev->parent == dev->pdev->dev.parent) {
+ bcm->dev = dev;
+ break;
+ }
+ }
+
+ if (bcm->dev)
+ bcm_gpio_set_power(bcm->dev, true);
+
+ spin_unlock(&bcm_device_list_lock);
+
return 0;
}
@@ -108,6 +185,12 @@ static int bcm_close(struct hci_uart *hu)
BT_DBG("hu %p", hu);
+ /* Protect bcm->dev against removal of the device or driver */
+ spin_lock(&bcm_device_list_lock);
+ if (bcm_device_exists(bcm->dev))
+ bcm_gpio_set_power(bcm->dev, false);
+ spin_unlock(&bcm_device_list_lock);
+
skb_queue_purge(&bcm->txq);
kfree_skb(bcm->rx_skb);
kfree(bcm);
@@ -232,6 +315,113 @@ static struct sk_buff *bcm_dequeue(struct hci_uart *hu)
return skb_dequeue(&bcm->txq);
}
+static const struct acpi_gpio_params device_wakeup_gpios = { 0, 0, false };
+static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
+
+static const struct acpi_gpio_mapping acpi_bcm_default_gpios[] = {
+ { "device-wakeup-gpios", &device_wakeup_gpios, 1 },
+ { "shutdown-gpios", &shutdown_gpios, 1 },
+ { },
+};
+
+static int bcm_acpi_probe(struct bcm_device *dev)
+{
+ struct platform_device *pdev = dev->pdev;
+ const struct acpi_device_id *id;
+ struct gpio_desc *gpio;
+ int ret;
+
+ id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
+ if (!id)
+ return -ENODEV;
+
+ /* Retrieve GPIO data */
+ dev->name = dev_name(&pdev->dev);
+ ret = acpi_dev_add_driver_gpios(ACPI_COMPANION(&pdev->dev),
+ acpi_bcm_default_gpios);
+ if (ret)
+ return ret;
+
+ dev->clk = devm_clk_get(&pdev->dev, NULL);
+
+ gpio = devm_gpiod_get(&pdev->dev, "device-wakeup");
+ if (!IS_ERR(gpio)) {
+ ret = gpiod_direction_output(gpio, 0);
+ if (ret)
+ return ret;
+ dev->device_wakeup = gpio;
+ }
+
+ gpio = devm_gpiod_get(&pdev->dev, "shutdown");
+ if (!IS_ERR(gpio)) {
+ ret = gpiod_direction_output(gpio, 0);
+ if (ret)
+ return ret;
+ dev->shutdown = gpio;
+ }
+
+ /* 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;
+ }
+
+ return 0;
+}
+
+static int bcm_probe(struct platform_device *pdev)
+{
+ struct bcm_device *dev;
+ struct acpi_device_id *pdata = pdev->dev.platform_data;
+ int ret;
+
+ dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+
+ dev->pdev = pdev;
+
+ if (ACPI_HANDLE(&pdev->dev)) {
+ ret = bcm_acpi_probe(dev);
+ if (ret)
+ return ret;
+ } else if (pdata) {
+ dev->name = pdata->id;
+ } else {
+ return -ENODEV;
+ }
+
+ platform_set_drvdata(pdev, dev);
+
+ dev_info(&pdev->dev, "%s device registered.\n", dev->name);
+
+ /* Place this instance on the device list */
+ spin_lock(&bcm_device_list_lock);
+ list_add_tail(&dev->list, &bcm_device_list);
+ spin_unlock(&bcm_device_list_lock);
+
+ bcm_gpio_set_power(dev, false);
+
+ return 0;
+}
+
+static int bcm_remove(struct platform_device *pdev)
+{
+ struct bcm_device *dev = platform_get_drvdata(pdev);
+
+ spin_lock(&bcm_device_list_lock);
+ list_del(&dev->list);
+ spin_unlock(&bcm_device_list_lock);
+
+ acpi_dev_remove_driver_gpios(ACPI_COMPANION(&pdev->dev));
+
+ dev_info(&pdev->dev, "%s device unregistered.\n", dev->name);
+
+ return 0;
+}
+
static const struct hci_uart_proto bcm_proto = {
.id = HCI_UART_BCM,
.name = "BCM",
@@ -247,12 +437,34 @@ static const struct hci_uart_proto bcm_proto = {
.dequeue = bcm_dequeue,
};
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id bcm_acpi_match[] = {
+ { "BCM2E39", 0 },
+ { "BCM2E67", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(acpi, bcm_acpi_match);
+#endif
+
+static struct platform_driver bcm_driver = {
+ .probe = bcm_probe,
+ .remove = bcm_remove,
+ .driver = {
+ .name = "hci_bcm",
+ .acpi_match_table = ACPI_PTR(bcm_acpi_match),
+ },
+};
+
int __init bcm_init(void)
{
+ platform_driver_register(&bcm_driver);
+
return hci_uart_register_proto(&bcm_proto);
}
int __exit bcm_deinit(void)
{
+ platform_driver_unregister(&bcm_driver);
+
return hci_uart_unregister_proto(&bcm_proto);
}
--
1.9.1
--
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