On Wed, 2019-05-15 at 13:09 +0100, Biju Das wrote:
> The RZ/G2E cat874 board has a type-c connector connected to hd3ss3220 usb
> type-c drp port controller. This patch adds dual role switch support for
> the type-c connector using the usb role switch class framework.
>
> Signed-off-by: Biju Das <[email protected]>
> ---
> V5-->V6
> * Added graph api's to find the role supported by the connector.
> V4-->V5
> * Incorporated Shimoda-san's review comment
> (https://patchwork.kernel.org/patch/10902537/)
> V3-->V4
> * No Change
> V2-->V3
> * Incorporated Shimoda-san's review comment
> (https://patchwork.kernel.org/patch/10852507/)
> * Used renesas,usb-role-switch property for differentiating USB
> role switch associated with Type-C port controller driver.
> V1-->V2
> * Driver uses usb role clas for handling dual role switch and handling
> connect/disconnect events instead of extcon.
> ---
> drivers/usb/gadget/udc/renesas_usb3.c | 121
> ++++++++++++++++++++++++++++++++--
> 1 file changed, 114 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/usb/gadget/udc/renesas_usb3.c
> b/drivers/usb/gadget/udc/renesas_usb3.c
> index 7dc2485..1d41998 100644
> --- a/drivers/usb/gadget/udc/renesas_usb3.c
> +++ b/drivers/usb/gadget/udc/renesas_usb3.c
> @@ -24,6 +24,7 @@
> #include <linux/usb/ch9.h>
> #include <linux/usb/gadget.h>
> #include <linux/usb/of.h>
> +#include <linux/of_graph.h>
> #include <linux/usb/role.h>
>
> /* register definitions */
> @@ -351,6 +352,8 @@ struct renesas_usb3 {
> int disabled_count;
>
> struct usb_request *ep0_req;
> +
> + enum usb_role connection_state;
> u16 test_mode;
> u8 ep0_buf[USB3_EP0_BUF_SIZE];
> bool softconnect;
> @@ -359,6 +362,7 @@ struct renesas_usb3 {
> bool extcon_usb; /* check vbus and set EXTCON_USB */
> bool forced_b_device;
> bool start_to_connect;
> + bool dual_role_sw;
> };
>
> #define gadget_to_renesas_usb3(_gadget) \
> @@ -699,8 +703,10 @@ 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_by_role_sw(usb3, host);
> - usb3_vbus_out(usb3, a_dev);
> + if (!usb3->dual_role_sw || usb3->connection_state != USB_ROLE_NONE) {
> + 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) || usb3->start_to_connect)
> usb3_connect(usb3);
> @@ -716,7 +722,8 @@ static void usb3_check_id(struct renesas_usb3 *usb3)
> {
> usb3->extcon_host = usb3_is_a_device(usb3);
>
> - if (usb3->extcon_host && !usb3->forced_b_device)
> + if ((!usb3->dual_role_sw && usb3->extcon_host && !usb3->forced_b_device)
> + || usb3->connection_state == USB_ROLE_HOST)
> usb3_mode_config(usb3, true, true);
> else
> usb3_mode_config(usb3, false, false);
> @@ -2343,14 +2350,65 @@ static enum usb_role
> renesas_usb3_role_switch_get(struct device *dev)
> return cur_role;
> }
>
> -static int renesas_usb3_role_switch_set(struct device *dev,
> - enum usb_role role)
> +static void handle_ext_role_switch_states(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);
> +
> + switch (role) {
> + case USB_ROLE_NONE:
> + usb3->connection_state = USB_ROLE_NONE;
> + if (usb3->driver)
> + usb3_disconnect(usb3);
> + usb3_vbus_out(usb3, false);
> + break;
> + case USB_ROLE_DEVICE:
> + if (usb3->connection_state == USB_ROLE_NONE) {
> + usb3->connection_state = USB_ROLE_DEVICE;
> + usb3_set_mode(usb3, false);
> + if (usb3->driver)
> + usb3_connect(usb3);
> + } else if (cur_role == USB_ROLE_HOST) {
> + device_release_driver(host);
> + usb3_set_mode(usb3, false);
> + if (usb3->driver)
> + usb3_connect(usb3);
> + }
> + usb3_vbus_out(usb3, false);
> + break;
> + case USB_ROLE_HOST:
> + if (usb3->connection_state == USB_ROLE_NONE) {
> + if (usb3->driver)
> + usb3_disconnect(usb3);
> +
> + usb3->connection_state = USB_ROLE_HOST;
> + usb3_set_mode(usb3, true);
> + usb3_vbus_out(usb3, true);
> + if (device_attach(host) < 0)
> + dev_err(dev, "device_attach(host) failed\n");
> + } else if (cur_role == USB_ROLE_DEVICE) {
> + usb3_disconnect(usb3);
> + /* 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");
> + }
> + break;
> + default:
> + break;
> + }
> +}
> +
> +static void handle_role_switch_states(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);
> @@ -2361,6 +2419,20 @@ static int renesas_usb3_role_switch_set(struct device
> *dev,
> if (device_attach(host) < 0)
> dev_err(dev, "device_attach(host) failed\n");
> }
> +}
> +
> +static int renesas_usb3_role_switch_set(struct device *dev,
> + enum usb_role role)
> +{
> + struct renesas_usb3 *usb3 = dev_get_drvdata(dev);
> +
> + pm_runtime_get_sync(dev);
> +
> + if (usb3->dual_role_sw)
> + handle_ext_role_switch_states(dev, role);
> + else
> + handle_role_switch_states(dev, role);
> +
> pm_runtime_put(dev);
>
> return 0;
> @@ -2650,12 +2722,41 @@ static const unsigned int renesas_usb3_cable[] = {
> EXTCON_NONE,
> };
>
> -static const struct usb_role_switch_desc renesas_usb3_role_switch_desc = {
> +static 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 bool is_usb_dual_role_switch(struct device *dev)
To me, it's not good idea to pay an attention to specific consumer of
the role switch, assume any device could assign role if it get this USB
role switch, not only type-c connector
> +{
> + struct device_node *np = dev->of_node;
> + struct device_node *parent;
> + struct device_node *child;
> + bool ret = false;
> + const char *role_type = NULL;
> +
> + child = of_graph_get_endpoint_by_regs(np, -1, -1);
> + if (!child)
> + return ret;
> +
> + parent = of_graph_get_remote_port_parent(child);
> + of_node_put(child);
> + child = of_get_child_by_name(parent, "connector");
> + of_node_put(parent);
> + if (!child)
> + return ret;
> +
> + if (of_device_is_compatible(child, "usb-c-connector")) {
> + of_property_read_string(child, "data-role", &role_type);
> + if (role_type && (!strncmp(role_type, "dual", strlen("dual"))))
> + ret = true;
> + }
> +
> + of_node_put(child);
> + return ret;
> +}
> +
> static int renesas_usb3_probe(struct platform_device *pdev)
> {
> struct renesas_usb3 *usb3;
> @@ -2741,6 +2842,12 @@ static int renesas_usb3_probe(struct platform_device
> *pdev)
> if (ret < 0)
> goto err_dev_create;
>
> + if (device_property_read_bool(&pdev->dev, "usb-role-switch") &&
> + is_usb_dual_role_switch(&pdev->dev)) {
> + usb3->dual_role_sw = true;
> + renesas_usb3_role_switch_desc.fwnode = dev_fwnode(&pdev->dev);
> + }
> +
> INIT_WORK(&usb3->role_work, renesas_usb3_role_work);
> usb3->role_sw = usb_role_switch_register(&pdev->dev,
> &renesas_usb3_role_switch_desc);
