lkml.org 
[lkml]   [2016]   [Aug]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v6 4/8] usb: core: add power sequence handling for USB devices
    On Mon, Aug 15, 2016 at 05:13:14PM +0800, Peter Chen wrote:
    > Some hard-wired USB devices need to do power sequence to let the
    > device work normally, the typical power sequence like: enable USB
    > PHY clock, toggle reset pin, etc. But current Linux USB driver
    > lacks of such code to do it, it may cause some hard-wired USB devices
    > works abnormal or can't be recognized by controller at all.
    >
    > In this patch, it calls power sequence library APIs to finish
    > the power sequence events. At first, it calls pwrseq_alloc_generic
    > to create a generic power sequence instance, then it will do power
    > on sequence at hub's probe for all devices under this hub
    > (includes root hub).
    >
    > At hub_disconnect, it will do power off sequence which is at powered
    > on list.
    >
    > Signed-off-by: Peter Chen <peter.chen@nxp.com>
    > Tested-by Joshua Clayton <stillcompiling@gmail.com>

    Hi Alan,

    The power sequence library code has been reviewed several rounds, would
    you please help to review the change for USB part?

    Peter

    > ---
    > drivers/usb/core/Makefile | 1 +
    > drivers/usb/core/hub.c | 12 ++++--
    > drivers/usb/core/hub.h | 12 ++++++
    > drivers/usb/core/pwrseq.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++
    > 4 files changed, 122 insertions(+), 3 deletions(-)
    > create mode 100644 drivers/usb/core/pwrseq.c
    >
    > diff --git a/drivers/usb/core/Makefile b/drivers/usb/core/Makefile
    > index 9780877..39f2149 100644
    > --- a/drivers/usb/core/Makefile
    > +++ b/drivers/usb/core/Makefile
    > @@ -9,5 +9,6 @@ usbcore-y += port.o of.o
    >
    > usbcore-$(CONFIG_PCI) += hcd-pci.o
    > usbcore-$(CONFIG_ACPI) += usb-acpi.o
    > +usbcore-$(CONFIG_PWRSEQ_GENERIC) += pwrseq.o
    >
    > obj-$(CONFIG_USB) += usbcore.o
    > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
    > index bee1351..a346a8b 100644
    > --- a/drivers/usb/core/hub.c
    > +++ b/drivers/usb/core/hub.c
    > @@ -1700,6 +1700,7 @@ static void hub_disconnect(struct usb_interface *intf)
    > hub->error = 0;
    > hub_quiesce(hub, HUB_DISCONNECT);
    >
    > + hub_pwrseq_off(hub);
    > mutex_lock(&usb_port_peer_mutex);
    >
    > /* Avoid races with recursively_mark_NOTATTACHED() */
    > @@ -1733,6 +1734,7 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
    > struct usb_endpoint_descriptor *endpoint;
    > struct usb_device *hdev;
    > struct usb_hub *hub;
    > + int ret = -ENODEV;
    >
    > desc = intf->cur_altsetting;
    > hdev = interface_to_usbdev(intf);
    > @@ -1839,6 +1841,7 @@ descriptor_error:
    > INIT_DELAYED_WORK(&hub->leds, led_work);
    > INIT_DELAYED_WORK(&hub->init_work, NULL);
    > INIT_WORK(&hub->events, hub_event);
    > + INIT_LIST_HEAD(&hub->pwrseq_on_list);
    > usb_get_intf(intf);
    > usb_get_dev(hdev);
    >
    > @@ -1852,11 +1855,14 @@ descriptor_error:
    > if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
    > hub->quirk_check_port_auto_suspend = 1;
    >
    > - if (hub_configure(hub, endpoint) >= 0)
    > - return 0;
    > + if (hub_configure(hub, endpoint) >= 0) {
    > + ret = hub_pwrseq_on(hub);
    > + if (!ret)
    > + return 0;
    > + }
    >
    > hub_disconnect(intf);
    > - return -ENODEV;
    > + return ret;
    > }
    >
    > static int
    > diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
    > index 34c1a7e..9473f6f 100644
    > --- a/drivers/usb/core/hub.h
    > +++ b/drivers/usb/core/hub.h
    > @@ -78,6 +78,7 @@ struct usb_hub {
    > struct delayed_work init_work;
    > struct work_struct events;
    > struct usb_port **ports;
    > + struct list_head pwrseq_on_list; /* powered pwrseq node list */
    > };
    >
    > /**
    > @@ -166,3 +167,14 @@ static inline int hub_port_debounce_be_stable(struct usb_hub *hub,
    > {
    > return hub_port_debounce(hub, port1, false);
    > }
    > +
    > +#if IS_ENABLED(CONFIG_PWRSEQ_GENERIC)
    > +int hub_pwrseq_on(struct usb_hub *hub);
    > +void hub_pwrseq_off(struct usb_hub *hub);
    > +#else
    > +static inline int hub_pwrseq_on(struct usb_hub *hub)
    > +{
    > + return 0;
    > +}
    > +static inline void hub_pwrseq_off(struct usb_hub *hub) {}
    > +#endif /* CONFIG_PWRSEQ_GENERIC */
    > diff --git a/drivers/usb/core/pwrseq.c b/drivers/usb/core/pwrseq.c
    > new file mode 100644
    > index 0000000..837fe66
    > --- /dev/null
    > +++ b/drivers/usb/core/pwrseq.c
    > @@ -0,0 +1,100 @@
    > +/*
    > + * pwrseq.c USB device power sequence management
    > + *
    > + * Copyright (C) 2016 Freescale Semiconductor, Inc.
    > + * Author: Peter Chen <peter.chen@nxp.com>
    > + *
    > + * This program is free software: you can redistribute it and/or modify
    > + * it under the terms of the GNU General Public License version 2 of
    > + * the License as published by the Free Software Foundation.
    > + *
    > + * This program is distributed in the hope that it will be useful,
    > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
    > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    > + * GNU General Public License for more details.
    > + *
    > + * You should have received a copy of the GNU General Public License
    > + * along with this program. If not, see <http://www.gnu.org/licenses/>.
    > + */
    > +
    > +#include <linux/list.h>
    > +#include <linux/of.h>
    > +#include <linux/power/pwrseq.h>
    > +#include <linux/slab.h>
    > +#include <linux/usb.h>
    > +#include <linux/usb/hcd.h>
    > +
    > +#include "hub.h"
    > +
    > +struct usb_pwrseq_node {
    > + struct pwrseq *pwrseq;
    > + struct list_head list;
    > +};
    > +
    > +static int hub_of_pwrseq_on(struct device_node *np, struct usb_hub *hub)
    > +{
    > + struct pwrseq *pwrseq;
    > + struct usb_pwrseq_node *pwrseq_node;
    > + int ret;
    > +
    > + pwrseq = pwrseq_alloc_generic();
    > + if (IS_ERR(pwrseq))
    > + return PTR_ERR(pwrseq);
    > +
    > + ret = pwrseq_get(np, pwrseq);
    > + if (ret)
    > + goto pwr_free;
    > +
    > + ret = pwrseq_on(np, pwrseq);
    > + if (ret)
    > + goto pwr_put;
    > +
    > + pwrseq_node = kzalloc(sizeof(*pwrseq_node), GFP_KERNEL);
    > + pwrseq_node->pwrseq = pwrseq;
    > + list_add(&pwrseq_node->list, &hub->pwrseq_on_list);
    > +
    > + return 0;
    > +
    > +pwr_put:
    > + pwrseq_put(pwrseq);
    > +pwr_free:
    > + pwrseq_free(pwrseq);
    > + return ret;
    > +}
    > +
    > +int hub_pwrseq_on(struct usb_hub *hub)
    > +{
    > + struct device *parent;
    > + struct usb_device *hdev = hub->hdev;
    > + struct device_node *np;
    > + int ret;
    > +
    > + if (hdev->parent)
    > + parent = &hdev->dev;
    > + else
    > + parent = bus_to_hcd(hdev->bus)->self.controller;
    > +
    > + for_each_child_of_node(parent->of_node, np) {
    > + ret = hub_of_pwrseq_on(np, hub);
    > + if (ret)
    > + return ret;
    > + }
    > +
    > + return 0;
    > +}
    > +
    > +void hub_pwrseq_off(struct usb_hub *hub)
    > +{
    > + struct pwrseq *pwrseq;
    > + struct usb_pwrseq_node *pwrseq_node, *tmp_node;
    > +
    > + list_for_each_entry_safe(pwrseq_node, tmp_node,
    > + &hub->pwrseq_on_list, list) {
    > + pwrseq = pwrseq_node->pwrseq;
    > + pwrseq_off(pwrseq);
    > + pwrseq_put(pwrseq);
    > + pwrseq_free(pwrseq);
    > + list_del(&pwrseq_node->list);
    > + kfree(pwrseq_node);
    > + }
    > +}
    > --
    > 1.9.1
    >
    > --
    > To unsubscribe from this list: send the line "unsubscribe linux-usb" in
    > the body of a message to majordomo@vger.kernel.org
    > More majordomo info at http://vger.kernel.org/majordomo-info.html

    --

    Best Regards,
    Peter Chen

    \
     
     \ /
      Last update: 2016-09-17 09:57    [W:5.216 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site