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

[Michael Grzeschik]

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.

> 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

You should use these existing mx*_initialize_usb_hw functions to avoid
code duplication and add your mx6_initialize_usb_hw routine for mx6 there.

This devicetree based glue code in this file can be reused to
call the right mx*_initialize_usb_hw by the compatible.

We already have common flags available like i.e. MXC_EHCI_POWER_PINS_ENABLED
which is currently used to disable overcurrent detection.


> Signed-off-by: Richard Zhao <richard.zhao at 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?

> +
> +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.

> +{
> +	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

> +	}
> +
> +	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 },

> +	{ /* 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;

> +		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.

> +
> +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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