Message-ID: <50605CFB.5090402@gmail.com>
Date:	Mon, 24 Sep 2012 08:15:39 -0500
From:	Rob Herring <robherring2@...il.com>
To:	Kishon Vijay Abraham I <kishon@...com>
CC:	grant.likely@...retlab.ca, rob@...dley.net, b-cousson@...com,
	tony@...mide.com, linux@....linux.org.uk, balbi@...com,
	gregkh@...uxfoundation.org, devicetree-discuss@...ts.ozlabs.org,
	linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-omap@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-usb@...r.kernel.org
Subject: Re: [PATCH 1/5] drivers: usb: phy: add a new driver for omap usb2
 phy

On 09/06/2012 09:57 AM, Kishon Vijay Abraham I wrote:
> All phy related programming like enabling/disabling the clocks, powering
> on/off the phy is taken care of by this driver. It is also used for OTG
> related functionality like srp.
> 
> This also includes device tree support for usb2 phy driver and
> the documentation with device tree binding information is updated.
> 
> Currently writing to control module register is taken care in this
> driver which will be removed once the control module driver is in place.
> 
> Cc: Felipe Balbi <balbi@...com>
> Signed-off-by: Kishon Vijay Abraham I <kishon@...com>
> ---
>  Documentation/devicetree/bindings/usb/usb-phy.txt |   17 ++
>  drivers/usb/phy/Kconfig                           |    9 +
>  drivers/usb/phy/Makefile                          |    1 +
>  drivers/usb/phy/omap-usb2.c                       |  271 +++++++++++++++++++++
>  include/linux/usb/omap_usb.h                      |   46 ++++
>  include/linux/usb/phy_companion.h                 |   34 +++
>  6 files changed, 378 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/usb/usb-phy.txt
>  create mode 100644 drivers/usb/phy/omap-usb2.c
>  create mode 100644 include/linux/usb/omap_usb.h
>  create mode 100644 include/linux/usb/phy_companion.h
> 
> diff --git a/Documentation/devicetree/bindings/usb/usb-phy.txt b/Documentation/devicetree/bindings/usb/usb-phy.txt
> new file mode 100644
> index 0000000..80d4148
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/usb-phy.txt

This is a very generic name...

> @@ -0,0 +1,17 @@
> +USB PHY
> +
> +OMAP USB2 PHY
> +
> +Required properties:
> + - compatible: Should be "ti,omap-usb2"

...for a specific phy. However, I do think a generic binding to describe
host ctrlr to phy connections is needed.

> + - reg : Address and length of the register set for the device. Also
> +add the address of control module dev conf register until a driver for
> +control module is added

The dts should describe the h/w, not what you need for the current
driver. The 2nd reg field does not belong here.

> +
> +This is usually a subnode of ocp2scp to which it is connected.

How is usb port to phy connection described?

Rob

> +
> +usb2phy@...ad080 {
> +	compatible = "ti,omap-usb2";
> +	reg = <0x4a0ad080 0x58>,
> +	      <0x4a002300 0x4>;
> +};
> diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
> index 2838adb..63c339b 100644
> --- a/drivers/usb/phy/Kconfig
> +++ b/drivers/usb/phy/Kconfig
> @@ -4,6 +4,15 @@
>  comment "USB Physical Layer drivers"
>  	depends on USB || USB_GADGET
>  
> +config OMAP_USB2
> +	tristate "OMAP USB2 PHY Driver"
> +	select USB_OTG_UTILS
> +	help
> +	  Enable this to support the transceiver that is part of SOC. This
> +	  driver takes care of all the PHY functionality apart from comparator.
> +	  The USB OTG controller communicates with the comparator using this
> +	  driver.
> +
>  config USB_ISP1301
>  	tristate "NXP ISP1301 USB transceiver support"
>  	depends on USB || USB_GADGET
> diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
> index bb948fb..b069f29 100644
> --- a/drivers/usb/phy/Makefile
> +++ b/drivers/usb/phy/Makefile
> @@ -4,6 +4,7 @@
>  
>  ccflags-$(CONFIG_USB_DEBUG) := -DDEBUG
>  
> +obj-$(CONFIG_OMAP_USB2)			+= omap-usb2.o
>  obj-$(CONFIG_USB_ISP1301)		+= isp1301.o
>  obj-$(CONFIG_MV_U3D_PHY)		+= mv_u3d_phy.o
>  obj-$(CONFIG_USB_EHCI_TEGRA)	+= tegra_usb_phy.o
> diff --git a/drivers/usb/phy/omap-usb2.c b/drivers/usb/phy/omap-usb2.c
> new file mode 100644
> index 0000000..15ab3d6
> --- /dev/null
> +++ b/drivers/usb/phy/omap-usb2.c
> @@ -0,0 +1,271 @@
> +/*
> + * omap-usb2.c - USB PHY, talking to musb controller in OMAP.
> + *
> + * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * Author: Kishon Vijay Abraham I <kishon@...com>
> + *
> + * 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.
> + *
> + */
> +
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/of.h>
> +#include <linux/io.h>
> +#include <linux/usb/omap_usb.h>
> +#include <linux/usb/phy_companion.h>
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/delay.h>
> +
> +/**
> + * omap_usb2_set_comparator - links the comparator present in the sytem with
> + *	this phy
> + * @comparator - the companion phy(comparator) for this phy
> + *
> + * The phy companion driver should call this API passing the phy_companion
> + * filled with set_vbus and start_srp to be used by usb phy.
> + *
> + * For use by phy companion driver
> + */
> +int omap_usb2_set_comparator(struct phy_companion *comparator)
> +{
> +	struct omap_usb	*phy;
> +	struct usb_phy	*x = usb_get_phy(USB_PHY_TYPE_USB2);
> +
> +	if (IS_ERR(x))
> +		return -ENODEV;
> +
> +	phy = phy_to_omapusb(x);
> +	phy->comparator = comparator;
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(omap_usb2_set_comparator);
> +
> +/**
> + * omap_usb_phy_power - power on/off the phy using control module reg
> + * @phy: struct omap_usb *
> + * @on: 0 or 1, based on powering on or off the PHY
> + *
> + * XXX: Remove this function once control module driver gets merged
> + */
> +static void omap_usb_phy_power(struct omap_usb *phy, int on)
> +{
> +	u32 val;
> +
> +	if (on) {
> +		val = readl(phy->control_dev);
> +		if (val & PHY_PD) {
> +			writel(~PHY_PD, phy->control_dev);
> +			/* XXX: add proper documentation for this delay */
> +			mdelay(200);
> +		}
> +	} else {
> +		writel(PHY_PD, phy->control_dev);
> +	}
> +}
> +
> +static int omap_usb_set_vbus(struct usb_otg *otg, bool enabled)
> +{
> +	struct omap_usb *phy = phy_to_omapusb(otg->phy);
> +
> +	if (!phy->comparator)
> +		return -ENODEV;
> +
> +	return phy->comparator->set_vbus(phy->comparator, enabled);
> +}
> +
> +static int omap_usb_start_srp(struct usb_otg *otg)
> +{
> +	struct omap_usb *phy = phy_to_omapusb(otg->phy);
> +
> +	if (!phy->comparator)
> +		return -ENODEV;
> +
> +	return phy->comparator->start_srp(phy->comparator);
> +}
> +
> +static int omap_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
> +{
> +	struct usb_phy	*phy = otg->phy;
> +
> +	otg->host = host;
> +	if (!host)
> +		phy->state = OTG_STATE_UNDEFINED;
> +
> +	return 0;
> +}
> +
> +static int omap_usb_set_peripheral(struct usb_otg *otg,
> +		struct usb_gadget *gadget)
> +{
> +	struct usb_phy	*phy = otg->phy;
> +
> +	otg->gadget = gadget;
> +	if (!gadget)
> +		phy->state = OTG_STATE_UNDEFINED;
> +
> +	return 0;
> +}
> +
> +static int omap_usb2_suspend(struct usb_phy *x, int suspend)
> +{
> +	u32 ret;
> +	struct omap_usb *phy = phy_to_omapusb(x);
> +
> +	if (suspend && !phy->is_suspended) {
> +		omap_usb_phy_power(phy, 0);
> +		pm_runtime_put_sync(phy->dev);
> +		phy->is_suspended = 1;
> +	} else if (!suspend && phy->is_suspended) {
> +		ret = pm_runtime_get_sync(phy->dev);
> +		if (ret < 0) {
> +			dev_err(phy->dev, "get_sync failed with err %d\n",
> +									ret);
> +			return ret;
> +		}
> +		omap_usb_phy_power(phy, 1);
> +		phy->is_suspended = 0;
> +	}
> +
> +	return 0;
> +}
> +
> +static int __devinit omap_usb2_probe(struct platform_device *pdev)
> +{
> +	struct omap_usb			*phy;
> +	struct usb_otg			*otg;
> +	struct resource			*res;
> +
> +	phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL);
> +	if (!phy) {
> +		dev_err(&pdev->dev, "unable to allocate memory for USB2 PHY\n");
> +		return -ENOMEM;
> +	}
> +
> +	otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
> +	if (!otg) {
> +		dev_err(&pdev->dev, "unable to allocate memory for USB OTG\n");
> +		return -ENOMEM;
> +	}
> +
> +	phy->dev		= &pdev->dev;
> +
> +	phy->phy.dev		= phy->dev;
> +	phy->phy.label		= "omap-usb2";
> +	phy->phy.set_suspend	= omap_usb2_suspend;
> +	phy->phy.otg		= otg;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> +
> +	phy->control_dev = devm_request_and_ioremap(&pdev->dev, res);
> +	if (phy->control_dev == NULL) {
> +		dev_err(&pdev->dev, "Failed to obtain io memory\n");
> +		return -ENXIO;
> +	}
> +
> +	phy->is_suspended	= 1;
> +	omap_usb_phy_power(phy, 0);
> +
> +	otg->set_host		= omap_usb_set_host;
> +	otg->set_peripheral	= omap_usb_set_peripheral;
> +	otg->set_vbus		= omap_usb_set_vbus;
> +	otg->start_srp		= omap_usb_start_srp;
> +	otg->phy		= &phy->phy;
> +
> +	phy->wkupclk = devm_clk_get(phy->dev, "usb_phy_cm_clk32k");
> +	if (IS_ERR(phy->wkupclk)) {
> +		dev_err(&pdev->dev, "unable to get usb_phy_cm_clk32k\n");
> +		return PTR_ERR(phy->wkupclk);
> +	}
> +	clk_prepare(phy->wkupclk);
> +
> +	usb_add_phy(&phy->phy, USB_PHY_TYPE_USB2);
> +
> +	platform_set_drvdata(pdev, phy);
> +
> +	pm_runtime_enable(phy->dev);
> +
> +	return 0;
> +}
> +
> +static int __devexit omap_usb2_remove(struct platform_device *pdev)
> +{
> +	struct omap_usb	*phy = platform_get_drvdata(pdev);
> +
> +	clk_unprepare(phy->wkupclk);
> +	usb_remove_phy(&phy->phy);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM_RUNTIME
> +
> +static int omap_usb2_runtime_suspend(struct device *dev)
> +{
> +	struct platform_device	*pdev = to_platform_device(dev);
> +	struct omap_usb	*phy = platform_get_drvdata(pdev);
> +
> +	clk_disable(phy->wkupclk);
> +
> +	return 0;
> +}
> +
> +static int omap_usb2_runtime_resume(struct device *dev)
> +{
> +	u32 ret = 0;
> +	struct platform_device	*pdev = to_platform_device(dev);
> +	struct omap_usb	*phy = platform_get_drvdata(pdev);
> +
> +	ret = clk_enable(phy->wkupclk);
> +	if (ret < 0)
> +		dev_err(phy->dev, "Failed to enable wkupclk %d\n", ret);
> +
> +	return ret;
> +}
> +
> +static const struct dev_pm_ops omap_usb2_pm_ops = {
> +	SET_RUNTIME_PM_OPS(omap_usb2_runtime_suspend, omap_usb2_runtime_resume,
> +		NULL)
> +};
> +
> +#define DEV_PM_OPS     (&omap_usb2_pm_ops)
> +#else
> +#define DEV_PM_OPS     NULL
> +#endif
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id omap_usb2_id_table[] = {
> +	{ .compatible = "ti,omap-usb2" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, omap_usb2_id_table);
> +#endif
> +
> +static struct platform_driver omap_usb2_driver = {
> +	.probe		= omap_usb2_probe,
> +	.remove		= __devexit_p(omap_usb2_remove),
> +	.driver		= {
> +		.name	= "omap-usb2",
> +		.owner	= THIS_MODULE,
> +		.pm	= DEV_PM_OPS,
> +		.of_match_table = of_match_ptr(omap_usb2_id_table),
> +	},
> +};
> +
> +module_platform_driver(omap_usb2_driver);
> +
> +MODULE_ALIAS("platform: omap_usb2");
> +MODULE_AUTHOR("Texas Instruments Inc.");
> +MODULE_DESCRIPTION("OMAP USB2 phy driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/usb/omap_usb.h b/include/linux/usb/omap_usb.h
> new file mode 100644
> index 0000000..0ea17f8
> --- /dev/null
> +++ b/include/linux/usb/omap_usb.h
> @@ -0,0 +1,46 @@
> +/*
> + * omap_usb.h -- omap usb2 phy header file
> + *
> + * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * Author: Kishon Vijay Abraham I <kishon@...com>
> + *
> + * 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.
> + *
> + */
> +
> +#ifndef __DRIVERS_OMAP_USB2_H
> +#define __DRIVERS_OMAP_USB2_H
> +
> +#include <linux/usb/otg.h>
> +
> +struct omap_usb {
> +	struct usb_phy		phy;
> +	struct phy_companion	*comparator;
> +	struct device		*dev;
> +	u32 __iomem		*control_dev;
> +	struct clk		*wkupclk;
> +	u8			is_suspended:1;
> +};
> +
> +#define	PHY_PD	0x1
> +
> +#define	phy_to_omapusb(x)	container_of((x), struct omap_usb, phy)
> +
> +#if defined(CONFIG_OMAP_USB2) || defined(CONFIG_OMAP_USB2_MODULE)
> +extern int omap_usb2_set_comparator(struct phy_companion *comparator);
> +#else
> +static inline int omap_usb2_set_comparator(struct phy_companion *comparator)
> +{
> +	return -ENODEV;
> +}
> +#endif
> +
> +#endif /* __DRIVERS_OMAP_USB_H */
> diff --git a/include/linux/usb/phy_companion.h b/include/linux/usb/phy_companion.h
> new file mode 100644
> index 0000000..edd2ec2
> --- /dev/null
> +++ b/include/linux/usb/phy_companion.h
> @@ -0,0 +1,34 @@
> +/*
> + * phy-companion.h -- phy companion to indicate the comparator part of PHY
> + *
> + * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * Author: Kishon Vijay Abraham I <kishon@...com>
> + *
> + * 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.
> + *
> + */
> +
> +#ifndef __DRIVERS_PHY_COMPANION_H
> +#define __DRIVERS_PHY_COMPANION_H
> +
> +#include <linux/usb/otg.h>
> +
> +/* phy_companion to take care of VBUS, ID and srp capabilities */
> +struct phy_companion {
> +
> +	/* effective for A-peripheral, ignored for B devices */
> +	int	(*set_vbus)(struct phy_companion *x, bool enabled);
> +
> +	/* for B devices only:  start session with A-Host */
> +	int	(*start_srp)(struct phy_companion *x);
> +};
> +
> +#endif /* __DRIVERS_PHY_COMPANION_H */
> 

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