[PATCH 12/12] USB: chipidea: add imx usbmisc support

[linuxzsc@gmail.com (Richard Zhao)]

On Fri, Jul 13, 2012 at 02:25:45PM +0200, Michael Grzeschik wrote:
> On Thu, Jul 12, 2012 at 03:01:52PM +0800, Richard Zhao wrote:
> > i.MX usb controllers shares non-core registers, which may include
> > SoC specific controls. We take it as a usbmisc device and usbmisc
> > driver export functions needed by ci13xxx_imx driver.
> 
> So this is SoC and not chipidea specific and should not be sorted into
> this subdir.
Yes, but it's usb specific and serve chipidea usb IP.
> 
> > For example, Sabrelite board has bad over-current design, we can
> > usbmisc to disable over-current detect.
> 
> This driver layout is also reflected in:
> 
> arch/arm/mach-imx/ehci-imx*.c
It sounds sensible, but I'm not quite sure. I saw drivers are moving
out of there, event it's SoC specific, for example, clk, pinmux. And
the non-core registers might not only be setup onetime on boot, but
be called at runtime by usb driver. For now, it's set once.
> 
> You should use these existing mx*_initialize_usb_hw functions to avoid
> code duplication
I can not see what duplication it can avoid.
> and add your mx6_initialize_usb_hw routine for mx6 there.
Maybe.
> 
> This devicetree based glue code in this file can be reused to
> call the right mx*_initialize_usb_hw by the compatible.
The glue code makes it more like a normal driver. Doesn't it?
> 
> We already have common flags available like i.e. MXC_EHCI_POWER_PINS_ENABLED
> which is currently used to disable overcurrent detection.
The flags may be replace with properties in DT bindings.
> 
> 
> > Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
> > ---
> >  .../devicetree/bindings/usb/imx-usbmisc.txt        |   15 ++
> >  drivers/usb/chipidea/Makefile                      |    2 +-
> >  drivers/usb/chipidea/ci13xxx_imx.c                 |    4 +
> >  drivers/usb/chipidea/imx_usbmisc.c                 |  144 ++++++++++++++++++++
> >  4 files changed, 164 insertions(+), 1 deletion(-)
> >  create mode 100644 Documentation/devicetree/bindings/usb/imx-usbmisc.txt
> >  create mode 100644 drivers/usb/chipidea/imx_usbmisc.c
> > 
> > diff --git a/Documentation/devicetree/bindings/usb/imx-usbmisc.txt b/Documentation/devicetree/bindings/usb/imx-usbmisc.txt
> > new file mode 100644
> > index 0000000..09f01ca
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/usb/imx-usbmisc.txt
> > @@ -0,0 +1,15 @@
> > +* Freescale i.MX non-core registers
> > +
> > +Required properties:
> > +- compatible: Should be "fsl,imx6q-usbmisc"
> > +- reg: Should contain registers location and length
> > +
> > +Optional properties:
> > +- fsl,disable-over-current: disable over current detect
> > +
> > +Examples:
> > +usbmisc at 02184800 {
> > +	compatible = "fsl,imx6q-usbmisc";
> > +	reg = <0x02184800 0x200>;
> > +	fsl,disable-over-current;
> > +};
> > diff --git a/drivers/usb/chipidea/Makefile b/drivers/usb/chipidea/Makefile
> > index 3f56b76..46fc31c 100644
> > --- a/drivers/usb/chipidea/Makefile
> > +++ b/drivers/usb/chipidea/Makefile
> > @@ -17,5 +17,5 @@ ifneq ($(CONFIG_PCI),)
> >  endif
> >  
> >  ifneq ($(CONFIG_OF_DEVICE),)
> > -	obj-$(CONFIG_USB_CHIPIDEA)	+= ci13xxx_imx.o
> > +	obj-$(CONFIG_USB_CHIPIDEA)	+= ci13xxx_imx.o imx_usbmisc.o
> >  endif
> > diff --git a/drivers/usb/chipidea/ci13xxx_imx.c b/drivers/usb/chipidea/ci13xxx_imx.c
> > index b3173d8..dd7f3a3 100644
> > --- a/drivers/usb/chipidea/ci13xxx_imx.c
> > +++ b/drivers/usb/chipidea/ci13xxx_imx.c
> > @@ -24,6 +24,8 @@
> >  
> >  #include "ci.h"
> >  
> > +int imx_usbmisc_init(struct device *usbdev);
> > +
> >  #define pdev_to_phy(pdev) \
> >  	((struct usb_phy *)platform_get_drvdata(pdev))
> >  #define ci_to_imx_data(ci) \
> > @@ -142,6 +144,8 @@ static int __devinit ci13xxx_imx_probe(struct platform_device *pdev)
> >  		dma_set_coherent_mask(&pdev->dev, *pdev->dev.dma_mask);
> >  	}
> >  
> > +	imx_usbmisc_init(&pdev->dev);
> > +
> >  	platform_set_drvdata(pdev, data);
> >  
> >  	plat_ci = ci13xxx_add_device(&pdev->dev,
> > diff --git a/drivers/usb/chipidea/imx_usbmisc.c b/drivers/usb/chipidea/imx_usbmisc.c
> > new file mode 100644
> > index 0000000..33a8ec0
> > --- /dev/null
> > +++ b/drivers/usb/chipidea/imx_usbmisc.c
> > @@ -0,0 +1,144 @@
> > +/*
> > + * Copyright 2012 Freescale Semiconductor, Inc.
> > + *
> > + * The code contained herein is licensed under the GNU General Public
> > + * License. You may obtain a copy of the GNU General Public License
> > + * Version 2 or later at the following locations:
> > + *
> > + * http://www.opensource.org/licenses/gpl-license.html
> > + * http://www.gnu.org/copyleft/gpl.html
> > + */
> > +
> > +#include <linux/module.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/clk.h>
> > +#include <linux/err.h>
> > +#include <asm/io.h>
> > +
> > +struct usbmisc;
> > +
> > +struct soc_data {
> > +	int (*init) (struct usbmisc *usbmisc, int id);
> > +	void (*exit) (struct usbmisc *usbmisc, int id);
> > +};
> > +
> > +struct usbmisc {
> > +	struct soc_data *soc_data;
> > +	void __iomem *base;
> > +	struct clk *clk;
> > +
> > +	int dis_oc:1;
> > +};
> > +
> > +/* Since we only have one usbmisc device at runtime, we global variables */
> > +static struct usbmisc *usbmisc;
> 
> Global variable?
Yes. we only have one usbmisc.
> 
> > +
> > +static int imx6q_usbmisc_init(struct usbmisc *usbmisc, int id)
> 
> What is initialized here? How about "preconfigure"?
> Even better is to reuse mx*_initialize_usb_hw here.
It's used to call by ci13xxx_imx driver.
> 
> > +{
> > +	u32 reg;
> > +
> > +	if (usbmisc->dis_oc) {
> > +		reg = readl_relaxed(usbmisc->base + id * 4);
> > +		writel_relaxed(reg | (1 << 7), usbmisc->base + id * 4);
> 
> #define IMX6_OTG_CTRL_USBMISC        1 << 7
yes.
> 
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static struct soc_data imx6q_data = {
> > +	.init = imx6q_usbmisc_init,
> > +};
> > +
> > +
> > +static const struct of_device_id imx_usbmisc_dt_ids[] = {
> > +	{ .compatible = "fsl,imx6q-usbmisc", .data = &imx6q_data },
> 
>         something like this:
> 	{ .compatible = "fsl,imx6q-usbmisc", .data = &mx6_initialize_usb_hw },
It's designed not only used when initialization.
> 
> > +	{ /* sentinel */ }
> > +};
> > +
> > +static int __devinit imx_usbmisc_probe(struct platform_device *pdev)
> > +{
> > +	struct resource	*res;
> > +	struct usbmisc *data;
> > +	const struct of_device_id *of_id =
> > +			of_match_device(imx_usbmisc_dt_ids, &pdev->dev);
> > +
> > +	int ret;
> > +
> > +	if (usbmisc)
> > +		return -EBUSY;
> > +
> > +	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> > +	if (!data)
> > +		return -ENOMEM;
> > +
> > +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +	data->base = devm_request_and_ioremap(&pdev->dev, res);
> > +	if (!data->base)
> > +		return -EADDRNOTAVAIL;
> > +
> > +	data->clk = devm_clk_get(&pdev->dev, NULL);
> > +	if (IS_ERR(data->clk)) {
> > +		dev_err(&pdev->dev,
> > +			"failed to get clock, err=%ld\n", PTR_ERR(data->clk));
> > +		return PTR_ERR(data->clk);
> > +	}
> > +
> > +	ret = clk_prepare_enable(data->clk);
> > +	if (!ret) {
> 
> Better:
>         if (ret)
>                 return ret;
To me, it does not make much difference.
> 
> > +		if (of_find_property(pdev->dev.of_node,
> > +			"fsl,disable-over-current", NULL))
> > +			data->dis_oc = 1;
> > +		data->soc_data = of_id->data;
> > +		usbmisc = data;
> > +	}
> > +
>         if (of_find_property(pdev->dev.of_node,
>         ...
> 
> > +	return ret;
> > +}
> > +
> > +static int __devexit imx_usbmisc_remove(struct platform_device *pdev)
> > +{
> > +	clk_disable_unprepare(usbmisc->clk);
> > +	return 0;
> > +}
> > +
> > +static struct platform_driver imx_usbmisc_driver = {
> > +	.probe = imx_usbmisc_probe,
> > +	.remove = __devexit_p(imx_usbmisc_remove),
> > +	.driver = {
> > +		.name = "imx_usbmisc",
> > +		.owner = THIS_MODULE,
> > +		.of_match_table = imx_usbmisc_dt_ids,
> > +	 },
> > +};
> > +
> > +int imx_usbmisc_init(struct device *usbdev)
> > +{
> > +	struct device_node *np = usbdev->of_node;
> > +	int ret;
> > +
> > +	if (!usbmisc)
> > +		return 0;
> > +
> > +	ret = of_alias_get_id(np, "usb");
> > +	if (ret < 0) {
> > +		dev_err(usbdev, "failed to get alias id, errno %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	return usbmisc->soc_data->init(usbmisc, ret);
> > +}
> > +EXPORT_SYMBOL_GPL(imx_usbmisc_init);
> 
> EXPORT_SYMBOL is only needed because it is
> compliled as an extra kernel module.
ci13xxx_imx may be module.

Thanks
Richard
> 
> > +
> > +static int __init imx_usbmisc_drv_init(void)
> > +{
> > +	return platform_driver_register(&imx_usbmisc_driver);
> > +}
> > +subsys_initcall(imx_usbmisc_drv_init);
> > +
> > +static void __exit imx_usbmisc_drv_exit(void)
> > +{
> > +	platform_driver_unregister(&imx_usbmisc_driver);
> > +}
> > +module_exit(imx_usbmisc_drv_exit);
> > +
> > +MODULE_LICENSE("GPL v2");
> > -- 
> > 1.7.9.5
> 
> Thanks,
> Michael
> 
> -- 
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