From bf594c1070f5c34a2576a725eef69cba2686b98d Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 29 Jun 2018 13:52:20 -0400 Subject: USB: gadget: Document that certain ep operations can be called in interrupt context This documentation patch specifies that certain USB gadget endpoint operations may be called in interrupt context: usb_ep_queue, usb_ep_dequeue, usb_ep_set_halt, usb_ep_clear_halt, usb_ep_set_wedge, usb_ep_fifo_status, and usb_ep_fifo_flush; while others must be called in process context: usb_ep_enable and usb_ep_disable. Signed-off-by: Alan Stern Signed-off-by: Felipe Balbi --- drivers/usb/gadget/udc/core.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'drivers/usb/gadget/udc') diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index cab5e4f09924..af88b48c1cea 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -87,6 +87,8 @@ EXPORT_SYMBOL_GPL(usb_ep_set_maxpacket_limit); * configurable, with more generic names like "ep-a". (remember that for * USB, "in" means "towards the USB master".) * + * This routine must be called in process context. + * * returns zero, or a negative error code. */ int usb_ep_enable(struct usb_ep *ep) @@ -119,6 +121,8 @@ EXPORT_SYMBOL_GPL(usb_ep_enable); * gadget drivers must call usb_ep_enable() again before queueing * requests to the endpoint. * + * This routine must be called in process context. + * * returns zero, or a negative error code. */ int usb_ep_disable(struct usb_ep *ep) @@ -241,6 +245,8 @@ EXPORT_SYMBOL_GPL(usb_ep_free_request); * Note that @req's ->complete() callback must never be called from * within usb_ep_queue() as that can create deadlock situations. * + * This routine may be called in interrupt context. + * * Returns zero, or a negative error code. Endpoints that are not enabled * report errors; errors will also be * reported when the usb peripheral is disconnected. @@ -284,6 +290,8 @@ EXPORT_SYMBOL_GPL(usb_ep_queue); * at the head of the queue) except as part of disconnecting from usb. Such * restrictions prevent drivers from supporting configuration changes, * even to configuration zero (a "chapter 9" requirement). + * + * This routine may be called in interrupt context. */ int usb_ep_dequeue(struct usb_ep *ep, struct usb_request *req) { @@ -311,6 +319,8 @@ EXPORT_SYMBOL_GPL(usb_ep_dequeue); * current altsetting, see usb_ep_clear_halt(). When switching altsettings, * it's simplest to use usb_ep_enable() or usb_ep_disable() for the endpoints. * + * This routine may be called in interrupt context. + * * Returns zero, or a negative error code. On success, this call sets * underlying hardware state that blocks data transfers. * Attempts to halt IN endpoints will fail (returning -EAGAIN) if any @@ -336,6 +346,8 @@ EXPORT_SYMBOL_GPL(usb_ep_set_halt); * for endpoints that aren't reconfigured, after clearing any other state * in the endpoint's i/o queue. * + * This routine may be called in interrupt context. + * * Returns zero, or a negative error code. On success, this call clears * the underlying hardware state reflecting endpoint halt and data toggle. * Note that some hardware can't support this request (like pxa2xx_udc), @@ -360,6 +372,8 @@ EXPORT_SYMBOL_GPL(usb_ep_clear_halt); * requests. If the gadget driver clears the halt status, it will * automatically unwedge the endpoint. * + * This routine may be called in interrupt context. + * * Returns zero on success, else negative errno. */ int usb_ep_set_wedge(struct usb_ep *ep) @@ -388,6 +402,8 @@ EXPORT_SYMBOL_GPL(usb_ep_set_wedge); * written OUT to it by the host. Drivers that need precise handling for * fault reporting or recovery may need to use this call. * + * This routine may be called in interrupt context. + * * This returns the number of such bytes in the fifo, or a negative * errno if the endpoint doesn't use a FIFO or doesn't support such * precise handling. @@ -415,6 +431,8 @@ EXPORT_SYMBOL_GPL(usb_ep_fifo_status); * an endpoint fifo after abnormal transaction terminations. The call * must never be used except when endpoint is not being used for any * protocol translation. + * + * This routine may be called in interrupt context. */ void usb_ep_fifo_flush(struct usb_ep *ep) { -- cgit v1.2.3 From 39facfa01c9fc64f90233d1734882f0a0cafe36a Mon Sep 17 00:00:00 2001 From: Yoshihiro Shimoda Date: Fri, 27 Jul 2018 10:50:40 +0900 Subject: usb: gadget: udc: renesas_usb3: Add register of usb role switch This patch adds role switch support for R-Car SoCs into the USB 3.0 peripheral driver. Some R-Car SoCs (e.g. R-Car H3) have USB 3.0 dual-role device controller which has the USB 3.0 xHCI host and Renesas USB 3.0 peripheral. Unfortunately, the mode change register (DRD_CON) contains the USB 3.0 peripheral controller side only. So, this renesas_usb3 driver manages the DRD_CON now. However, in peripheral mode, the host should stop. Also the host hardware needs to reinitialize its own registers when the mode changes from peripheral to host mode. Otherwise, the host cannot work correctly (e.g. detect a device as high-speed). To achieve this reinitialization by a driver, this driver also registers a role switch driver to manage the DRD_CON and get a device pointer of usb 3.0 host from "companion" property of OF. Then, when the usb role is changed, renesas_usb3_role_switch_set() will attach/release the xhci-plat driver to reinitialize the host hardware. Signed-off-by: Yoshihiro Shimoda Reviewed-by: Heikki Krogerus Signed-off-by: Felipe Balbi --- drivers/usb/gadget/udc/Kconfig | 1 + drivers/usb/gadget/udc/renesas_usb3.c | 84 ++++++++++++++++++++++++++++++++++- 2 files changed, 84 insertions(+), 1 deletion(-) (limited to 'drivers/usb/gadget/udc') diff --git a/drivers/usb/gadget/udc/Kconfig b/drivers/usb/gadget/udc/Kconfig index 1df4dedffe86..0a16cbd4e528 100644 --- a/drivers/usb/gadget/udc/Kconfig +++ b/drivers/usb/gadget/udc/Kconfig @@ -193,6 +193,7 @@ config USB_RENESAS_USB3 tristate 'Renesas USB3.0 Peripheral controller' depends on ARCH_RENESAS || COMPILE_TEST depends on EXTCON + select USB_ROLE_SWITCH help Renesas USB3.0 Peripheral controller is a USB peripheral controller that supports super, high, and full speed USB 3.0 data transfers. diff --git a/drivers/usb/gadget/udc/renesas_usb3.c b/drivers/usb/gadget/udc/renesas_usb3.c index 7cf98c793e04..1f879b3f2c96 100644 --- a/drivers/usb/gadget/udc/renesas_usb3.c +++ b/drivers/usb/gadget/udc/renesas_usb3.c @@ -23,6 +23,8 @@ #include #include #include +#include +#include /* register definitions */ #define USB3_AXI_INT_STA 0x008 @@ -335,6 +337,11 @@ struct renesas_usb3 { struct phy *phy; struct dentry *dentry; + struct usb_role_switch *role_sw; + struct device *host_dev; + struct work_struct role_work; + enum usb_role role; + struct renesas_usb3_ep *usb3_ep; int num_usb3_eps; @@ -651,6 +658,14 @@ static void usb3_check_vbus(struct renesas_usb3 *usb3) } } +static void renesas_usb3_role_work(struct work_struct *work) +{ + struct renesas_usb3 *usb3 = + container_of(work, struct renesas_usb3, role_work); + + usb_role_switch_set_role(usb3->role_sw, usb3->role); +} + static void usb3_set_mode(struct renesas_usb3 *usb3, bool host) { if (host) @@ -659,6 +674,16 @@ static void usb3_set_mode(struct renesas_usb3 *usb3, bool host) usb3_set_bit(usb3, DRD_CON_PERI_CON, USB3_DRD_CON); } +static void usb3_set_mode_by_role_sw(struct renesas_usb3 *usb3, bool host) +{ + if (usb3->role_sw) { + usb3->role = host ? USB_ROLE_HOST : USB_ROLE_DEVICE; + schedule_work(&usb3->role_work); + } else { + usb3_set_mode(usb3, host); + } +} + static void usb3_vbus_out(struct renesas_usb3 *usb3, bool enable) { if (enable) @@ -672,7 +697,7 @@ static void usb3_mode_config(struct renesas_usb3 *usb3, bool host, bool a_dev) unsigned long flags; spin_lock_irqsave(&usb3->lock, flags); - usb3_set_mode(usb3, host); + usb3_set_mode_by_role_sw(usb3, host); usb3_vbus_out(usb3, a_dev); /* for A-Peripheral or forced B-device mode */ if ((!host && a_dev) || @@ -2302,6 +2327,41 @@ static const struct usb_gadget_ops renesas_usb3_gadget_ops = { .set_selfpowered = renesas_usb3_set_selfpowered, }; +static enum usb_role renesas_usb3_role_switch_get(struct device *dev) +{ + struct renesas_usb3 *usb3 = dev_get_drvdata(dev); + enum usb_role cur_role; + + pm_runtime_get_sync(dev); + cur_role = usb3_is_host(usb3) ? USB_ROLE_HOST : USB_ROLE_DEVICE; + pm_runtime_put(dev); + + return cur_role; +} + +static int renesas_usb3_role_switch_set(struct device *dev, + enum usb_role role) +{ + struct renesas_usb3 *usb3 = dev_get_drvdata(dev); + struct device *host = usb3->host_dev; + enum usb_role cur_role = renesas_usb3_role_switch_get(dev); + + pm_runtime_get_sync(dev); + if (cur_role == USB_ROLE_HOST && role == USB_ROLE_DEVICE) { + device_release_driver(host); + usb3_set_mode(usb3, false); + } else if (cur_role == USB_ROLE_DEVICE && role == USB_ROLE_HOST) { + /* Must set the mode before device_attach of the host */ + usb3_set_mode(usb3, true); + /* This device_attach() might sleep */ + if (device_attach(host) < 0) + dev_err(dev, "device_attach(host) failed\n"); + } + pm_runtime_put(dev); + + return 0; +} + static ssize_t role_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { @@ -2405,6 +2465,8 @@ static int renesas_usb3_remove(struct platform_device *pdev) debugfs_remove_recursive(usb3->dentry); device_remove_file(&pdev->dev, &dev_attr_role); + usb_role_switch_unregister(usb3->role_sw); + usb_del_gadget_udc(&usb3->gadget); renesas_usb3_dma_free_prd(usb3, &pdev->dev); @@ -2562,6 +2624,12 @@ static const unsigned int renesas_usb3_cable[] = { EXTCON_NONE, }; +static const struct usb_role_switch_desc renesas_usb3_role_switch_desc = { + .set = renesas_usb3_role_switch_set, + .get = renesas_usb3_role_switch_get, + .allow_userspace_control = true, +}; + static int renesas_usb3_probe(struct platform_device *pdev) { struct renesas_usb3 *usb3; @@ -2647,6 +2715,20 @@ static int renesas_usb3_probe(struct platform_device *pdev) if (ret < 0) goto err_dev_create; + INIT_WORK(&usb3->role_work, renesas_usb3_role_work); + usb3->role_sw = usb_role_switch_register(&pdev->dev, + &renesas_usb3_role_switch_desc); + if (!IS_ERR(usb3->role_sw)) { + usb3->host_dev = usb_of_get_companion_dev(&pdev->dev); + if (!usb3->host_dev) { + /* If not found, this driver will not use a role sw */ + usb_role_switch_unregister(usb3->role_sw); + usb3->role_sw = NULL; + } + } else { + usb3->role_sw = NULL; + } + usb3->workaround_for_vbus = priv->workaround_for_vbus; renesas_usb3_debugfs_init(usb3, &pdev->dev); -- cgit v1.2.3