On Thu, May 31, 2018 at 03:11:33PM +0900, Yoshihiro Shimoda wrote: > 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 <yoshihiro.shimoda...@renesas.com>
Reviewed-by: Heikki Krogerus <heikki.kroge...@linux.intel.com> > --- > This patch set is based on Felipe's usb.git / testing/next branch > (commit id = 47265c067c0d129f3a0e94bc221293a780af9d78). > > Changes from v5 (https://patchwork.kernel.org/patch/10426483/): > - Add a new function "usb3_set_mode_by_role_sw()" instead of reusing > usb3_set_mode() and add _usb3_set_mode(). > - Change a coding style of container_of. > - Revise an error message in renesas_usb3_role_switch_set(). > - Add "const" for "renesas_usb3_role_switch_desc". > - Simplify a condition check of usb_of_get_companion_dev(). > > Changes from RFC v4 (https://patchwork.kernel.org/patch/10418265/): > - Use "companion" device tree property simply instead of device_connection > APIs with OF graph. > - Merge patch 2 and 3 to one. > - Revise the commit log (I should had revised this on RFC v4 though). > > Changes from RFC v3: > - Rebase latest usb.git / testing/next branch. > - Add graph parse into device_connection_find_match(). > - Use workqueue to call _usb3_set_mode() in patch 3. > (I realized renesas_usb3_role_switch_set() cannot run on atomic because > device_attach() might sleep.) > > Changes from RFC v2: > - Add registering usb role switch into drivers/usb/gadget/udc/renesas_usb3 > because hardware resource (a register) is shared and remove individual > usb role switch driver/dt-bindings for R-Car. > - Remove "usb_role_switch_get_by_graph" API because the renesas_usb3 driver > doesn't need such API now. > > Changes from RFC: > - Remove "device-connection-id" and "usb role switch driver" dt-bingings. > - Remove drivers/of code. > - Add a new API for find the connection by using graph on devcon.c and > roles.c. > - Use each new API on the rcar usb role switch and renesas_usb3 drivers. > - Update the dtsi file for r8a7795. > > > drivers/usb/gadget/udc/Kconfig | 1 + > drivers/usb/gadget/udc/renesas_usb3.c | 84 > ++++++++++++++++++++++++++++++++++- > 2 files changed, 84 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/gadget/udc/Kconfig b/drivers/usb/gadget/udc/Kconfig > index b838cae..78823cd 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 && HAS_DMA > + 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 5caf78b..f44a4b1 100644 > --- a/drivers/usb/gadget/udc/renesas_usb3.c > +++ b/drivers/usb/gadget/udc/renesas_usb3.c > @@ -23,6 +23,8 @@ > #include <linux/uaccess.h> > #include <linux/usb/ch9.h> > #include <linux/usb/gadget.h> > +#include <linux/usb/of.h> > +#include <linux/usb/role.h> > > /* 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 int renesas_usb3_set_selfpowered(struct > usb_gadget *gadget, int is_self) > .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) > { > @@ -2417,6 +2477,8 @@ 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); > > @@ -2573,6 +2635,12 @@ static void renesas_usb3_init_ram(struct renesas_usb3 > *usb3, struct device *dev, > 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; > @@ -2658,6 +2726,20 @@ 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); -- heikki
