[U-Boot] [PATCH v3 u-boot 1/3] usb: host: Add simple of glue driver for DWC3 USB Controllers integration

[Jean-Jacques Hiblot]

On 11/04/2018 17:08, Neil Armstrong wrote:
> This is a port of the dwc3-of-simple driver from Linux to enable/deassert
> clock and resets of a simple DWC3 Controller HW glue.
>
> 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 | 109 ++++++++++++++++++++++++++++++++++++++
>   3 files changed, 117 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..54a5f60
> --- /dev/null
> +++ b/drivers/usb/host/dwc3-of-simple.c
> @@ -0,0 +1,109 @@
> +/*
> + * 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 {
> +	struct clk_bulk		clks;
> +	struct reset_ctl_bulk	resets;
> +};
> +
> +static int dwc3_of_simple_reset_init(struct udevice *dev,
> +				     struct dwc3_of_simple *simple)
> +{
> +	int ret;
> +
> +	ret = reset_get_bulk(dev, &simple->resets);
> +	if (ret == -ENOTSUPP)
> +		return 0;
> +	else if (ret)
> +		return ret;
> +
> +	ret = reset_deassert_bulk(&simple->resets);
> +	if (ret) {
> +		reset_release_bulk(&simple->resets);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int dwc3_of_simple_clk_init(struct udevice *dev,
> +				   struct dwc3_of_simple *simple)
> +{
> +	int ret;
> +
> +	ret = clk_get_bulk(dev, &simple->clks);
> +	if (ret == -ENOTSUPP)

Must be ENOSYS instead of ENOTSUPP, otherwise probe fails on platform not using the clk framework

tested-by: Jean-Jacques hiblot <jjhiblot at ti.com>

> +		return 0;
> +	if (ret)
> +		return ret;
> +
> +#if CONFIG_IS_ENABLED(CLK)
> +	ret = clk_enable_bulk(&simple->clks);
> +	if (ret) {
> +		clk_release_bulk(&simple->clks);
> +		return ret;
> +	}
> +#endif
> +
> +	return 0;
> +}
> +
> +static int dwc3_of_simple_probe(struct udevice *dev)
> +{
> +	struct dwc3_of_simple *simple = dev_get_platdata(dev);
> +	int ret;
> +
> +	ret = dwc3_of_simple_clk_init(dev, simple);
> +	if (ret)
> +		return ret;
> +
> +	ret = dwc3_of_simple_reset_init(dev, simple);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int dwc3_of_simple_remove(struct udevice *dev)
> +{
> +	struct dwc3_of_simple *simple = dev_get_platdata(dev);
> +
> +	reset_release_bulk(&simple->resets);
> +
> +	clk_release_bulk(&simple->clks);
> +
> +	return dm_scan_fdt_dev(dev);
> +}
> +
> +static const struct udevice_id dwc3_of_simple_ids[] = {
> +	{ .compatible = "amlogic,meson-gxl-dwc3" },
> +	{ }
> +};
> +
> +U_BOOT_DRIVER(dwc3_of_simple) = {
> +	.name = "dwc3-of-simple",
> +	.id = UCLASS_SIMPLE_BUS,
> +	.of_match = dwc3_of_simple_ids,
> +	.probe = dwc3_of_simple_probe,
> +	.remove = dwc3_of_simple_remove,
> +	.platdata_auto_alloc_size = sizeof(struct dwc3_of_simple),
> +	.flags = DM_FLAG_ALLOC_PRIV_DMA,
> +};