diff options
Diffstat (limited to 'drivers/usb/otg/otg.c')
-rw-r--r-- | drivers/usb/otg/otg.c | 181 |
1 files changed, 158 insertions, 23 deletions
diff --git a/drivers/usb/otg/otg.c b/drivers/usb/otg/otg.c index 801e597a154..1bf60a22595 100644 --- a/drivers/usb/otg/otg.c +++ b/drivers/usb/otg/otg.c @@ -11,60 +11,195 @@ #include <linux/kernel.h> #include <linux/export.h> +#include <linux/err.h> #include <linux/device.h> +#include <linux/slab.h> #include <linux/usb/otg.h> -static struct usb_phy *phy; +static LIST_HEAD(phy_list); +static DEFINE_SPINLOCK(phy_lock); + +static struct usb_phy *__usb_find_phy(struct list_head *list, + enum usb_phy_type type) +{ + struct usb_phy *phy = NULL; + + list_for_each_entry(phy, list, head) { + if (phy->type != type) + continue; + + return phy; + } + + return ERR_PTR(-ENODEV); +} + +static void devm_usb_phy_release(struct device *dev, void *res) +{ + struct usb_phy *phy = *(struct usb_phy **)res; + + usb_put_phy(phy); +} + +static int devm_usb_phy_match(struct device *dev, void *res, void *match_data) +{ + return res == match_data; +} /** - * usb_get_transceiver - find the (single) USB transceiver + * devm_usb_get_phy - find the USB PHY + * @dev - device that requests this phy + * @type - the type of the phy the controller requires * - * Returns the transceiver driver, after getting a refcount to it; or - * null if there is no such transceiver. The caller is responsible for - * calling usb_put_transceiver() to release that count. + * Gets the phy using usb_get_phy(), and associates a device with it using + * devres. On driver detach, release function is invoked on the devres data, + * then, devres data is freed. * * For use by USB host and peripheral drivers. */ -struct usb_phy *usb_get_transceiver(void) +struct usb_phy *devm_usb_get_phy(struct device *dev, enum usb_phy_type type) { - if (phy) - get_device(phy->dev); + struct usb_phy **ptr, *phy; + + ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return NULL; + + phy = usb_get_phy(type); + if (!IS_ERR(phy)) { + *ptr = phy; + devres_add(dev, ptr); + } else + devres_free(ptr); + + return phy; +} +EXPORT_SYMBOL(devm_usb_get_phy); + +/** + * usb_get_phy - find the USB PHY + * @type - the type of the phy the controller requires + * + * Returns the phy driver, after getting a refcount to it; or + * -ENODEV if there is no such phy. The caller is responsible for + * calling usb_put_phy() to release that count. + * + * For use by USB host and peripheral drivers. + */ +struct usb_phy *usb_get_phy(enum usb_phy_type type) +{ + struct usb_phy *phy = NULL; + unsigned long flags; + + spin_lock_irqsave(&phy_lock, flags); + + phy = __usb_find_phy(&phy_list, type); + if (IS_ERR(phy)) { + pr_err("unable to find transceiver of type %s\n", + usb_phy_type_string(type)); + goto err0; + } + + get_device(phy->dev); + +err0: + spin_unlock_irqrestore(&phy_lock, flags); + return phy; } -EXPORT_SYMBOL(usb_get_transceiver); +EXPORT_SYMBOL(usb_get_phy); + +/** + * devm_usb_put_phy - release the USB PHY + * @dev - device that wants to release this phy + * @phy - the phy returned by devm_usb_get_phy() + * + * destroys the devres associated with this phy and invokes usb_put_phy + * to release the phy. + * + * For use by USB host and peripheral drivers. + */ +void devm_usb_put_phy(struct device *dev, struct usb_phy *phy) +{ + int r; + + r = devres_destroy(dev, devm_usb_phy_release, devm_usb_phy_match, phy); + dev_WARN_ONCE(dev, r, "couldn't find PHY resource\n"); +} +EXPORT_SYMBOL(devm_usb_put_phy); /** - * usb_put_transceiver - release the (single) USB transceiver - * @x: the transceiver returned by usb_get_transceiver() + * usb_put_phy - release the USB PHY + * @x: the phy returned by usb_get_phy() * - * Releases a refcount the caller received from usb_get_transceiver(). + * Releases a refcount the caller received from usb_get_phy(). * * For use by USB host and peripheral drivers. */ -void usb_put_transceiver(struct usb_phy *x) +void usb_put_phy(struct usb_phy *x) { if (x) put_device(x->dev); } -EXPORT_SYMBOL(usb_put_transceiver); +EXPORT_SYMBOL(usb_put_phy); /** - * usb_set_transceiver - declare the (single) USB transceiver - * @x: the USB transceiver to be used; or NULL + * usb_add_phy - declare the USB PHY + * @x: the USB phy to be used; or NULL + * @type - the type of this PHY * - * This call is exclusively for use by transceiver drivers, which + * This call is exclusively for use by phy drivers, which * coordinate the activities of drivers for host and peripheral * controllers, and in some cases for VBUS current regulation. */ -int usb_set_transceiver(struct usb_phy *x) +int usb_add_phy(struct usb_phy *x, enum usb_phy_type type) +{ + int ret = 0; + unsigned long flags; + struct usb_phy *phy; + + if (x && x->type != USB_PHY_TYPE_UNDEFINED) { + dev_err(x->dev, "not accepting initialized PHY %s\n", x->label); + return -EINVAL; + } + + spin_lock_irqsave(&phy_lock, flags); + + list_for_each_entry(phy, &phy_list, head) { + if (phy->type == type) { + ret = -EBUSY; + dev_err(x->dev, "transceiver type %s already exists\n", + usb_phy_type_string(type)); + goto out; + } + } + + x->type = type; + list_add_tail(&x->head, &phy_list); + +out: + spin_unlock_irqrestore(&phy_lock, flags); + return ret; +} +EXPORT_SYMBOL(usb_add_phy); + +/** + * usb_remove_phy - remove the OTG PHY + * @x: the USB OTG PHY to be removed; + * + * This reverts the effects of usb_add_phy + */ +void usb_remove_phy(struct usb_phy *x) { - if (phy && x) - return -EBUSY; - phy = x; - return 0; + unsigned long flags; + + spin_lock_irqsave(&phy_lock, flags); + if (x) + list_del(&x->head); + spin_unlock_irqrestore(&phy_lock, flags); } -EXPORT_SYMBOL(usb_set_transceiver); +EXPORT_SYMBOL(usb_remove_phy); const char *otg_state_string(enum usb_otg_state state) { |