[PATCH v3 RESEND 4/4] usb: core: add phy notify connect and disconnect
Greg Kroah-Hartman
gregkh at linuxfoundation.org
Thu Dec 7 02:08:03 PST 2023
On Thu, Dec 07, 2023 at 03:38:07PM +0800, Stanley Chang wrote:
> In Realtek SoC, the parameter of usb phy is designed to can dynamic
> tuning base on port status. Therefore, add a notify callback of generic
> phy driver when usb device connect and disconnect change.
>
> The Realtek phy driver is designed to dynamically adjust disconnection
> level and calibrate phy parameters. When the device connected bit changes
> and when the disconnected bit changes, do connection change notification:
>
> Check if portstatus is USB_PORT_STAT_CONNECTION and portchange is
> USB_PORT_STAT_C_CONNECTION.
> 1. The device is connected, the driver lowers the disconnection level and
> calibrates the phy parameters.
> 2. The device disconnects, the driver increases the disconnect level and
> calibrates the phy parameters.
>
> Generic phy driver in usb core framework does not support device connect
> and disconnect notifications. Therefore, we add an api to notify phy
> the connection changes.
>
> Additionally, the generic phy only specifies primary_hcd in the original
> design. Added specific "usb2-phy" on primary_hcd and "usb3-phy" on
> shared_hcd.
>
> Signed-off-by: Stanley Chang <stanley_chang at realtek.com>
> ---
> v2 to v3:
> No change
> v1 to v2 change:
> rebase the driver to remove the part of usb phy notify API
> ---
> drivers/usb/core/hcd.c | 14 +++++--
> drivers/usb/core/hub.c | 29 +++++++++++++
> drivers/usb/core/phy.c | 94 ++++++++++++++++++++++++++++++++++++++++++
> drivers/usb/core/phy.h | 3 ++
> 4 files changed, 136 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index 12b6dfeaf658..992284461ad8 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -2794,10 +2794,16 @@ int usb_add_hcd(struct usb_hcd *hcd,
> struct usb_device *rhdev;
> struct usb_hcd *shared_hcd;
>
> - if (!hcd->skip_phy_initialization && usb_hcd_is_primary_hcd(hcd)) {
> - hcd->phy_roothub = usb_phy_roothub_alloc(hcd->self.sysdev);
> - if (IS_ERR(hcd->phy_roothub))
> - return PTR_ERR(hcd->phy_roothub);
> + if (!hcd->skip_phy_initialization) {
> + if (usb_hcd_is_primary_hcd(hcd)) {
> + hcd->phy_roothub = usb_phy_roothub_alloc(hcd->self.sysdev);
> + if (IS_ERR(hcd->phy_roothub))
> + return PTR_ERR(hcd->phy_roothub);
> + } else {
> + hcd->phy_roothub = usb_phy_roothub_alloc_usb3_phy(hcd->self.sysdev);
> + if (IS_ERR(hcd->phy_roothub))
> + return PTR_ERR(hcd->phy_roothub);
> + }
>
> retval = usb_phy_roothub_init(hcd->phy_roothub);
> if (retval)
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index 87480a6e6d93..65c0454ee70a 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -37,6 +37,7 @@
> #include <asm/byteorder.h>
>
> #include "hub.h"
> +#include "phy.h"
> #include "otg_productlist.h"
>
> #define USB_VENDOR_GENESYS_LOGIC 0x05e3
> @@ -622,6 +623,34 @@ static int hub_ext_port_status(struct usb_hub *hub, int port1, int type,
> ret = 0;
> }
> mutex_unlock(&hub->status_mutex);
> +
> + /*
> + * There is no need to lock status_mutex here, because status_mutex
> + * protects hub->status, and the phy driver only checks the port
> + * status without changing the status.
> + */
> + if (!ret) {
> + struct usb_device *hdev = hub->hdev;
> +
> + /*
> + * Only roothub will be notified of connection changes,
> + * since the USB PHY only cares about changes at the next
> + * level.
> + */
> + if (is_root_hub(hdev)) {
> + struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
> + bool connect;
> + bool connect_change;
> +
> + connect_change = *change & USB_PORT_STAT_C_CONNECTION;
> + connect = *status & USB_PORT_STAT_CONNECTION;
> + if (connect_change && connect)
> + usb_phy_roothub_notify_connect(hcd->phy_roothub, port1 - 1);
> + else if (connect_change)
> + usb_phy_roothub_notify_disconnect(hcd->phy_roothub, port1 - 1);
> + }
> + }
> +
> return ret;
> }
>
> diff --git a/drivers/usb/core/phy.c b/drivers/usb/core/phy.c
> index fb1588e7c282..26585fc1ec32 100644
> --- a/drivers/usb/core/phy.c
> +++ b/drivers/usb/core/phy.c
> @@ -19,6 +19,29 @@ struct usb_phy_roothub {
> struct list_head list;
> };
>
> +static int usb_phy_roothub_add_phy_by_name(struct device *dev, const char *name,
> + struct list_head *list)
> +{
> + struct usb_phy_roothub *roothub_entry;
> + struct phy *phy;
> +
> + phy = devm_of_phy_get(dev, dev->of_node, name);
> + if (IS_ERR(phy))
> + return PTR_ERR(phy);
> +
> + roothub_entry = devm_kzalloc(dev, sizeof(*roothub_entry), GFP_KERNEL);
> + if (!roothub_entry)
> + return -ENOMEM;
> +
> + INIT_LIST_HEAD(&roothub_entry->list);
> +
> + roothub_entry->phy = phy;
> +
> + list_add_tail(&roothub_entry->list, list);
> +
> + return 0;
> +}
> +
> static int usb_phy_roothub_add_phy(struct device *dev, int index,
> struct list_head *list)
> {
> @@ -65,6 +88,9 @@ struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev)
>
> INIT_LIST_HEAD(&phy_roothub->list);
>
> + if (!usb_phy_roothub_add_phy_by_name(dev, "usb2-phy", &phy_roothub->list))
> + return phy_roothub;
> +
> for (i = 0; i < num_phys; i++) {
> err = usb_phy_roothub_add_phy(dev, i, &phy_roothub->list);
> if (err)
> @@ -75,6 +101,32 @@ struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev)
> }
> EXPORT_SYMBOL_GPL(usb_phy_roothub_alloc);
>
> +struct usb_phy_roothub *usb_phy_roothub_alloc_usb3_phy(struct device *dev)
> +{
> + struct usb_phy_roothub *phy_roothub;
> + int num_phys;
> +
> + if (!IS_ENABLED(CONFIG_GENERIC_PHY))
> + return NULL;
> +
> + num_phys = of_count_phandle_with_args(dev->of_node, "phys",
> + "#phy-cells");
> + if (num_phys <= 0)
> + return NULL;
> +
> + phy_roothub = devm_kzalloc(dev, sizeof(*phy_roothub), GFP_KERNEL);
> + if (!phy_roothub)
> + return ERR_PTR(-ENOMEM);
> +
> + INIT_LIST_HEAD(&phy_roothub->list);
> +
> + if (!usb_phy_roothub_add_phy_by_name(dev, "usb3-phy", &phy_roothub->list))
> + return phy_roothub;
> +
> + return NULL;
> +}
> +EXPORT_SYMBOL_GPL(usb_phy_roothub_alloc_usb3_phy);
> +
> int usb_phy_roothub_init(struct usb_phy_roothub *phy_roothub)
> {
> struct usb_phy_roothub *roothub_entry;
> @@ -172,6 +224,48 @@ int usb_phy_roothub_calibrate(struct usb_phy_roothub *phy_roothub)
> }
> EXPORT_SYMBOL_GPL(usb_phy_roothub_calibrate);
>
> +int usb_phy_roothub_notify_connect(struct usb_phy_roothub *phy_roothub, int port)
> +{
> + struct usb_phy_roothub *roothub_entry;
> + struct list_head *head;
> + int err;
> +
> + if (!phy_roothub)
> + return 0;
How can phy_roothub ever be NULL?
> +
> + head = &phy_roothub->list;
> +
> + list_for_each_entry(roothub_entry, head, list) {
> + err = phy_notify_connect(roothub_entry->phy, port);
> + if (err)
> + return err;
> + }
>
You walk a list with no locking at all? That does not seem right at
all.
Also, this is a new function that is exported with no documentation?
Please fix.
thanks,
greg k-h
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