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Message-id: <56600E3E.6080300@samsung.com>
Date: Thu, 03 Dec 2015 18:41:18 +0900
From: Chanwoo Choi <cw00.choi@...sung.com>
To: Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: MyungJoo Ham <myungjoo.ham@...sung.com>,
David Cohen <david.a.cohen@...ux.intel.com>,
Lu Baolu <baolu.lu@...ux.intel.com>,
Mathias Nyman <mathias.nyman@...ux.intel.com>,
Felipe Balbi <balbi@...com>, linux-usb@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCHv2 1/2] extcon: add driver for Intel USB mux
Hi Heikki,
I'm sorry for delay reply.
On 2015년 12월 03일 18:29, Heikki Krogerus wrote:
> 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@...ux.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@...ux.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);
I do never want to add some specific funtcion for only this driver.
I think is not appropriate way.
- intel_usb_mux_unregister
- intel_usb_mux_register
The client driver using extcon driver should use the standard extcon API
for code consistency. Also, I'll do the more detailed review for this patch.
> 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) { }
ditto.
> +#endif /* CONFIG_EXTCON_INTEL_USB */
> +
> +#endif /* _INTEL_USB_MUX_H */
>
Thanks,
Chanwoo Choi
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