[U-Boot] [PATCH u-boot 1/3] usb: host: Add simple of glue driver for DWC3 USB Controllers integration

[Marek Vasut]

On 03/29/2018 04:27 PM, Neil Armstrong wrote:
> On 29/03/2018 16:24, Marek Vasut wrote:
>> On 03/29/2018 04:23 PM, Neil Armstrong wrote:
>>> On 29/03/2018 15:52, Marek Vasut wrote:
>>>> On 03/29/2018 03:42 PM, Neil Armstrong wrote:
>>>>> Signed-off-by: Neil Armstrong <narmstrong at baylibre.com>
>>>>> ---
>>>>>  drivers/usb/host/Kconfig          |   7 ++
>>>>>  drivers/usb/host/Makefile         |   1 +
>>>>>  drivers/usb/host/dwc3-of-simple.c | 187 ++++++++++++++++++++++++++++++++++++++
>>>>>  3 files changed, 195 insertions(+)
>>>>>  create mode 100644 drivers/usb/host/dwc3-of-simple.c
>>>>>
>>>>> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
>>>>> index a7249b7..6caa615 100644
>>>>> --- a/drivers/usb/host/Kconfig
>>>>> +++ b/drivers/usb/host/Kconfig
>>>>> @@ -21,6 +21,13 @@ config USB_XHCI_DWC3
>>>>>  	  Say Y or if your system has a Dual Role SuperSpeed
>>>>>  	  USB controller based on the DesignWare USB3 IP Core.
>>>>>  
>>>>> +config USB_XHCI_DWC3_OF_SIMPLE
>>>>> +	bool "DesignWare USB3 DRD Generic OF Simple Glue Layer"
>>>>> +	select MISC
>>>>> +	help
>>>>> +	  Support USB2/3 functionality in simple SoC integrations with
>>>>> +	  USB controller based on the DesignWare USB3 IP Core.
>>>>> +
>>>>>  config USB_XHCI_MVEBU
>>>>>  	bool "MVEBU USB 3.0 support"
>>>>>  	default y
>>>>> diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
>>>>> index 9819489..abe4f90 100644
>>>>> --- a/drivers/usb/host/Makefile
>>>>> +++ b/drivers/usb/host/Makefile
>>>>> @@ -49,6 +49,7 @@ obj-$(CONFIG_USB_EHCI_ZYNQ) += ehci-zynq.o
>>>>>  # xhci
>>>>>  obj-$(CONFIG_USB_XHCI_HCD) += xhci.o xhci-mem.o xhci-ring.o
>>>>>  obj-$(CONFIG_USB_XHCI_DWC3) += xhci-dwc3.o
>>>>> +obj-$(CONFIG_USB_XHCI_DWC3_OF_SIMPLE) += dwc3-of-simple.o
>>>>>  obj-$(CONFIG_USB_XHCI_ROCKCHIP) += xhci-rockchip.o
>>>>>  obj-$(CONFIG_USB_XHCI_ZYNQMP) += xhci-zynqmp.o
>>>>>  obj-$(CONFIG_USB_XHCI_KEYSTONE) += xhci-keystone.o
>>>>> diff --git a/drivers/usb/host/dwc3-of-simple.c b/drivers/usb/host/dwc3-of-simple.c
>>>>> new file mode 100644
>>>>> index 0000000..826a996
>>>>> --- /dev/null
>>>>> +++ b/drivers/usb/host/dwc3-of-simple.c
>>>>> @@ -0,0 +1,187 @@
>>>>> +/*
>>>>> + * dwc3-of-simple.c - OF glue layer for simple integrations
>>>>> + *
>>>>> + * Copyright (c) 2015 Texas Instruments Incorporated - http://www.ti.com
>>>>> + *
>>>>> + * Author: Felipe Balbi <balbi at ti.com>
>>>>> + *
>>>>> + * Copyright (C) 2018 BayLibre, SAS
>>>>> + * Author: Neil Armstrong <narmstron at baylibre.com>
>>>>> + *
>>>>> + * SPDX-License-Identifier:     GPL-2.0+
>>>>> + */
>>>>> +
>>>>> +#include <common.h>
>>>>> +#include <dm.h>
>>>>> +#include <fdtdec.h>
>>>>> +#include <reset.h>
>>>>> +#include <clk.h>
>>>>> +
>>>>> +DECLARE_GLOBAL_DATA_PTR;
>>>>> +
>>>>> +struct dwc3_of_simple {
>>>>> +#if CONFIG_IS_ENABLED(CLK)
>>>>> +	struct clk		*clks;
>>>>> +	int			num_clocks;
>>>>> +#endif
>>>>> +#if CONFIG_IS_ENABLED(DM_RESET)
>>>>> +	struct reset_ctl	*resets;
>>>>> +	int			num_resets;
>>>>> +#endif
>>>>> +};
>>>>> +
>>>>> +#if CONFIG_IS_ENABLED(DM_RESET)
>>>>> +static int dwc3_of_simple_reset_init(struct udevice *dev,
>>>>> +				     struct dwc3_of_simple *simple,
>>>>> +				     int count)
>>>>> +{
>>>>> +	int i, ret, err;
>>>>> +
>>>>> +	if (!count)
>>>>> +		return 0;
>>>>> +
>>>>> +	simple->resets = devm_kcalloc(dev, count, sizeof(struct reset_ctl),
>>>>> +				      GFP_KERNEL);
>>>>> +	if (!simple->resets)
>>>>> +		return -ENOMEM;
>>>>> +
>>>>> +	for (i = 0; i < count; i++) {
>>>>> +		ret = reset_get_by_index(dev, i, &simple->resets[i]);
>>>>> +		if (ret < 0)
>>>>> +			break;
>>>>> +
>>>>> +		ret = reset_request(&simple->resets[i]);
>>>>> +		if (ret) {
>>>>> +			pr_err("failed to request reset line %d\n", i);
>>>>> +			reset_free(&simple->resets[i]);
>>>>> +			goto reset_err;
>>>>> +		}
>>>>> +
>>>>> +		
>>>>> +		++simple->num_resets;
>>>>> +	}
>>>>> +
>>>>> +	for (i = 0; i < simple->num_resets; i++) {
>>>>> +		ret = reset_deassert(&simple->resets[i]);
>>>>> +		if (ret && ret != -ENOSYS && ret != -ENOTSUPP) {
>>>>> +			pr_err("failed to deassert reset line %d\n", i);
>>>>> +			goto reset_err;
>>>>> +		}
>>>>> +	}
>>>>> +
>>>>> +	return 0;
>>>>
>>>> This looks like some driver I've seen before. Isn't there similar code
>>>> for simple EHCI or OHCI driver already ?
>>>>
>>>
>>> Hi,
>>>
>>> This is not an EHCI/OHCI driver, only the glue to init the clocks and reset,
>>> it's the exact same as the drivers/usb/dwc3/dwc3-of-simple.c adapted to U-Boot.
>>>
>>> yes, similar code exists in drivers/usb/host/ehci-generic.c and
>>> drivers/usb/host/ohci-generic.c but the goal here is not to initialize the controller
>>> but only the glue.
>>
>> Can't we recycle that code instead of having three copies of similar stuff ?
>>
> 
> Sure, where should I put this code ? the clock and resets are stored in the driver's platdata.

Something-common I guess ?

-- 
Best regards,
Marek Vasut