Sascha & Shawn, Felipe & Alex,
What's your opinion where I put this driver? The usbmisc drivers is
SoC specific and provide callbacks to ci13xxx_imx driver at runtime.
- How to organize the driver
This patch is designed to put all per-soc driver in one file. But
I plan to put it in discrete files.
- Where to put it
Option 1: arch/arm/mach-imx/ehci-imxXXX.c
Option 2: drivers/usb/chipidea/imx/ , yes, we may need a folder.
Both is fine for me.
On Fri, Jul 13, 2012 at 04:14:27PM +0200, Marc Kleine-Budde wrote:
> On 07/13/2012 04:02 PM, Richard Zhao wrote:
> > 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.
>
> I don't care where this code is located.
I need maintainers' instruction here. :)
>
> >>> 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.
>
> We want to use the chipidea driver for the other imx, too. We already
> have existing code for the non-DT case in arch/arm/mach-imx/ehci-imx*.c.
> So we need to glue these functions to the DT or duplicate the code,
> which is to be avoided.
The existing code is too simple. ci13xxx_imx may call them at runtime.
>
> >> and add your mx6_initialize_usb_hw routine for mx6 there.
> > Maybe.
>
> Or at least next to the other imx usb-misc code (wherever that will end up).
>
> >> 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.
>
> Yes, write some code that extracts these flags from the DT and then
> calls the existing code (for the existing imx platforms).
>
> >>> Signed-off-by: Richard Zhao <richard.zhao@xxxxxxxxxxxxx>
> >>> ---
> >>> .../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@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.
>
> Not the the compiler, but IMHO the common pattern in the kernel is:
>
> ret = sensible_init();
> if (ret)
> return ret;
>
> do_work();
>
> >>
> >>> + 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.
>
> Why make the usb_misc an independent module, why not just link it into
> the ci13xxx_imx.ko
Yes
Thanks
Richard
>
> Marc
> --
> Pengutronix e.K. | Marc Kleine-Budde |
> Industrial Linux Solutions | Phone: +49-231-2826-924 |
> Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
> Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
>
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