From 0395ffc1ee0509df11ad830772c22d13627e02ec Mon Sep 17 00:00:00 2001 From: Frederic Danis Date: Tue, 11 Aug 2015 16:35:35 +0200 Subject: [PATCH] Bluetooth: hci_bcm: Add PM for BCM devices 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 Signed-off-by: Marcel Holtmann --- 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 23523e140a9a..6ac66364684d 100644 --- a/drivers/bluetooth/hci_bcm.c +++ b/drivers/bluetooth/hci_bcm.c @@ -25,6 +25,12 @@ #include #include #include +#include +#include +#include +#include +#include +#include #include #include @@ -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); } -- 2.20.1