lkml.org 
[lkml]   [2015]   [Dec]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCHv2 1/2] extcon: add driver for Intel USB mux
    Date
    Several Intel PCHs and SOCs have an internal mux that is
    used to share one USB port between USB Device Controller and
    xHCI. The mux is normally handled by System FW/BIOS, but not
    always. For those platforms where the FW does not take care
    of the mux, this driver is needed.

    Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
    ---
    drivers/extcon/Kconfig | 5 ++
    drivers/extcon/Makefile | 1 +
    drivers/extcon/extcon-intel-usb.c | 118 +++++++++++++++++++++++++++++++++++
    include/linux/extcon/intel_usb_mux.h | 31 +++++++++
    4 files changed, 155 insertions(+)
    create mode 100644 drivers/extcon/extcon-intel-usb.c
    create mode 100644 include/linux/extcon/intel_usb_mux.h

    diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
    index 0cebbf6..0a7ccb1 100644
    --- a/drivers/extcon/Kconfig
    +++ b/drivers/extcon/Kconfig
    @@ -118,3 +118,8 @@ config EXTCON_USB_GPIO
    Used typically if GPIO is used for USB ID pin detection.

    endif
    +
    +config EXTCON_INTEL_USB
    + bool
    + depends on X86 && USB
    + select EXTCON
    diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
    index ba787d0..e6e031a 100644
    --- a/drivers/extcon/Makefile
    +++ b/drivers/extcon/Makefile
    @@ -15,3 +15,4 @@ obj-$(CONFIG_EXTCON_PALMAS) += extcon-palmas.o
    obj-$(CONFIG_EXTCON_RT8973A) += extcon-rt8973a.o
    obj-$(CONFIG_EXTCON_SM5502) += extcon-sm5502.o
    obj-$(CONFIG_EXTCON_USB_GPIO) += extcon-usb-gpio.o
    +obj-$(CONFIG_EXTCON_INTEL_USB) += extcon-intel-usb.o
    diff --git a/drivers/extcon/extcon-intel-usb.c b/drivers/extcon/extcon-intel-usb.c
    new file mode 100644
    index 0000000..3da6039
    --- /dev/null
    +++ b/drivers/extcon/extcon-intel-usb.c
    @@ -0,0 +1,118 @@
    +/**
    + * extcon-intel-usb.c - Driver for Intel USB mux
    + *
    + * Copyright (C) 2015 Intel Corporation
    + * Author: Heikki Krogerus <heikki.krogerus@linux.intel.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 as
    + * published by the Free Software Foundation.
    + */
    +
    +#include <linux/slab.h>
    +#include <linux/extcon.h>
    +
    +#include <linux/extcon/intel_usb_mux.h>
    +
    +#define INTEL_MUX_CFG0 0x00
    +#define INTEL_MUX_CFG1 0x04
    +
    +#define CFG0_SW_DRD_MODE_MASK 0x3
    +#define CFG0_SW_DRD_DYN 0
    +#define CFG0_SW_DRD_STATIC_HOST 1
    +#define CFG0_SW_DRD_STATIC_DEV 2
    +#define CFG0_SW_SYNC_SS_AND_HS BIT(2)
    +#define CFG0_SW_SWITCH_EN BIT(16)
    +#define CFG0_SW_IDPIN BIT(20)
    +#define CFG0_SW_IDPIN_EN BIT(21)
    +#define CFG0_SW_VBUS_VALID BIT(24)
    +
    +#define CFG1_MODE BIT(29)
    +
    +struct intel_usb_mux {
    + struct notifier_block nb;
    + struct extcon_dev edev;
    + void __iomem *regs;
    + u32 cfg0_ctx;
    +};
    +
    +static const int intel_mux_cable[] = {
    + EXTCON_USB_HOST,
    + EXTCON_NONE,
    +};
    +
    +static int intel_usb_mux_notifier(struct notifier_block *nb,
    + unsigned long old, void *ptr)
    +{
    + struct intel_usb_mux *mux = container_of(nb, struct intel_usb_mux, nb);
    + u32 val;
    +
    + if (mux->edev.state)
    + val = CFG0_SW_IDPIN_EN | CFG0_SW_DRD_STATIC_HOST;
    + else
    + val = CFG0_SW_IDPIN_EN | CFG0_SW_IDPIN | CFG0_SW_VBUS_VALID |
    + CFG0_SW_DRD_STATIC_DEV;
    +
    + writel(val, mux->regs);
    + return NOTIFY_OK;
    +}
    +
    +struct intel_usb_mux *intel_usb_mux_register(struct device *dev,
    + struct resource *r)
    +{
    + struct intel_usb_mux *mux;
    + int ret;
    +
    + mux = kzalloc(sizeof(*mux), GFP_KERNEL);
    + if (!mux)
    + return ERR_PTR(-ENOMEM);
    +
    + mux->regs = ioremap_nocache(r->start, resource_size(r));
    + if (!mux->regs) {
    + kfree(mux);
    + return ERR_PTR(-ENOMEM);
    + }
    +
    + mux->cfg0_ctx = readl(mux->regs + INTEL_MUX_CFG0);
    +
    + mux->edev.dev.parent = dev;
    + mux->edev.supported_cable = intel_mux_cable;
    +
    + ret = extcon_dev_register(&mux->edev);
    + if (ret)
    + goto err;
    +
    + mux->edev.name = "intel_usb_mux";
    + mux->edev.state = !!(readl(mux->regs + INTEL_MUX_CFG1) & CFG1_MODE);
    +
    + /* An external source needs to tell us what to do */
    + mux->nb.notifier_call = intel_usb_mux_notifier;
    + ret = extcon_register_notifier(&mux->edev, EXTCON_USB_HOST, &mux->nb);
    + if (ret) {
    + dev_err(&mux->edev.dev, "failed to register notifier\n");
    + extcon_dev_unregister(&mux->edev);
    + goto err;
    + }
    + return mux;
    +err:
    + iounmap(mux->regs);
    + kfree(mux);
    + return ERR_PTR(ret);
    +}
    +EXPORT_SYMBOL_GPL(intel_usb_mux_register);
    +
    +void intel_usb_mux_unregister(struct intel_usb_mux *mux)
    +{
    + if (!mux)
    + return;
    +
    + if (WARN_ON(IS_ERR_OR_NULL(extcon_get_extcon_dev(mux->edev.name))))
    + return;
    +
    + extcon_unregister_notifier(&mux->edev, EXTCON_USB_HOST, &mux->nb);
    + extcon_dev_unregister(&mux->edev);
    + writel(mux->cfg0_ctx, mux->regs + INTEL_MUX_CFG0);
    + iounmap(mux->regs);
    + kfree(mux);
    +}
    +EXPORT_SYMBOL_GPL(intel_usb_mux_unregister);
    diff --git a/include/linux/extcon/intel_usb_mux.h b/include/linux/extcon/intel_usb_mux.h
    new file mode 100644
    index 0000000..f18ce52
    --- /dev/null
    +++ b/include/linux/extcon/intel_usb_mux.h
    @@ -0,0 +1,31 @@
    +/*
    + * Driver for Intel USB mux
    + *
    + * Copyright (C) 2015 Intel Corporation
    + *
    + * This program is free software; you can redistribute it and/or modify
    + * it under the terms of the GNU General Public License version 2 as
    + * published by the Free Software Foundation.
    + */
    +
    +#ifndef _INTEL_USB_MUX_H
    +#define _INTEL_USB_MUX_H
    +
    +#include <linux/errno.h>
    +
    +struct intel_usb_mux;
    +
    +#ifdef CONFIG_EXTCON_INTEL_USB
    +struct intel_usb_mux *intel_usb_mux_register(struct device *dev,
    + struct resource *r);
    +void intel_usb_mux_unregister(struct intel_usb_mux *mux);
    +#else
    +static inline struct intel_usb_mux *intel_usb_mux_register(struct device *dev,
    + struct resource *r)
    +{
    + return ERR_PTR(-ENOTSUPP);
    +}
    +static inline void intel_usb_mux_unregister(struct intel_usb_mux *mux) { }
    +#endif /* CONFIG_EXTCON_INTEL_USB */
    +
    +#endif /* _INTEL_USB_MUX_H */
    --
    2.6.2


    \
     
     \ /
      Last update: 2015-12-03 10:41    [W:2.272 / U:0.656 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site