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

From: Marek Vasut <marex@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH u-boot 1/3] usb: host: Add simple of glue driver for DWC3 USB Controllers integration
Date: Thu, 29 Mar 2018 16:24:40 +0200	[thread overview]
Message-ID: <3b74b97c-a6db-80ca-b172-c4f20fe67c69@denx.de> (raw)
In-Reply-To: <549799c4-8e69-6c47-bad9-49d6c07c8caf@baylibre.com>

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@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@ti.com>
>>> + *
>>> + * Copyright (C) 2018 BayLibre, SAS
>>> + * Author: Neil Armstrong <narmstron@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 ?

-- 
Best regards,
Marek Vasut