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SubjectRe: [PATCH 2/8] usb: host: xhci-plat: Add support for the Armada 38x glue code
On Fri, Apr 18, 2014 at 12:22:37PM +0200, Gregory CLEMENT wrote:
> For the armada 38x SoCs which come with an xhci controller, specific
> initialization must be done during probe, especially in relation with
> the MBus windows initialization. This patch adds this support.
>
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> ---
> drivers/usb/host/Kconfig | 7 +++
> drivers/usb/host/Makefile | 1 +
> drivers/usb/host/xhci-mvebu.c | 105 ++++++++++++++++++++++++++++++++++++++++++
> drivers/usb/host/xhci-mvebu.h | 21 +++++++++
> drivers/usb/host/xhci-plat.c | 10 ++++
> 5 files changed, 144 insertions(+)
> create mode 100644 drivers/usb/host/xhci-mvebu.c
> create mode 100644 drivers/usb/host/xhci-mvebu.h
>
> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
> index 3d9e54062d62..e70943fac4a1 100644
> --- a/drivers/usb/host/Kconfig
> +++ b/drivers/usb/host/Kconfig
> @@ -29,6 +29,13 @@ if USB_XHCI_HCD
> config USB_XHCI_PLATFORM
> tristate
>
> +config USB_XHCI_MVEBU
> + tristate "xHCI support for Marvell Armada 38x"
> + select USB_XHCI_PLATFORM
> + ---help---
> + Say 'Y' to enable the support for the xHCI host controller
> + found in Marvell Armada 38x ARM SOCs.
> +
> endif # USB_XHCI_HCD
>
> config USB_EHCI_HCD
> diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
> index 7530468c9a4f..7a8db7f7dc01 100644
> --- a/drivers/usb/host/Makefile
> +++ b/drivers/usb/host/Makefile
> @@ -19,6 +19,7 @@ xhci-hcd-$(CONFIG_PCI) += xhci-pci.o
>
> ifneq ($(CONFIG_USB_XHCI_PLATFORM), )
> xhci-hcd-y += xhci-plat.o
> + xhci-hcd-$(CONFIG_USB_XHCI_MVEBU) += xhci-mvebu.o
> endif
>
> obj-$(CONFIG_USB_WHCI_HCD) += whci/
> diff --git a/drivers/usb/host/xhci-mvebu.c b/drivers/usb/host/xhci-mvebu.c
> new file mode 100644
> index 000000000000..dc9c7648ab65
> --- /dev/null
> +++ b/drivers/usb/host/xhci-mvebu.c
> @@ -0,0 +1,105 @@
> +/*
> + * Copyright (C) 2014 Marvell
> + * Author: Gregory CLEMENT <gregory.clement@free-electrons.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * version 2 as published by the Free Software Foundation.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/io.h>
> +#include <linux/mbus.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +
> +#include "xhci.h"
> +
> +#define USB3_MAX_WINDOWS 4
> +#define USB3_WIN_CTRL(w) (0x0 + ((w) * 8))
> +#define USB3_WIN_BASE(w) (0x4 + ((w) * 8))
> +
> +static void __init mv_usb3_conf_mbus_windows(void __iomem *base,
> + const struct mbus_dram_target_info *dram)
> +{
> + int win;
> +
> + /* Clear all existing windows */
> + for (win = 0; win < USB3_MAX_WINDOWS; win++) {
> + writel(0, base + USB3_WIN_CTRL(win));
> + writel(0, base + USB3_WIN_BASE(win));
> + }
> +
> + /* Program each DRAM CS in a seperate window */
> + for (win = 0; win < dram->num_cs; win++) {
> + const struct mbus_dram_window *cs = dram->cs + win;
> +
> + writel(((cs->size - 1) & 0xffff0000) | (cs->mbus_attr << 8) |
> + (dram->mbus_dram_target_id << 4) | 1,
> + base + USB3_WIN_CTRL(win));
> +
> + writel((cs->base & 0xffff0000), base + USB3_WIN_BASE(win));
> + }
> +}
> +
> +int xhci_mvebu_probe(struct platform_device *pdev)
> +{
> + struct resource *res;
> + void __iomem *base;
> + const struct mbus_dram_target_info *dram;
> + int ret;
> + struct clk *clk;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> + if (!res)
> + return -ENODEV;
> +
> + /*
> + * We don't use devm_ioremap() because this mapping should
> + * only exists for the duration of this probe function.
> + */
> + base = ioremap(res->start, resource_size(res));
> + if (!base)
> + return -ENODEV;
> +
> + clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(clk)) {
> + iounmap(base);
> + return PTR_ERR(clk);
> + }
> +
> + ret = clk_prepare_enable(clk);
> + if (ret < 0) {
> + iounmap(base);
> + return ret;
> + }

it's best to teach generic xhci-plat about clocks, just make it
optional.

> + dram = mv_mbus_dram_info();
> + mv_usb3_conf_mbus_windows(base, dram);
> +
> + /*
> + * This memory area was only needed to configure the MBus
> + * windows, and is therefore no longer useful.
> + */
> + iounmap(base);

so I suppose MBus is the Marvell interconnect, am I right ? Wouldn't you
be duplicating this sort of initialization for most drivers ?

> + ret = common_xhci_plat_probe(pdev, clk);

I would much rather reverse this, instead of exposing xhci-plat's probe,
turn this mbus initialization into a quirk which will ioremap the extra
resource, initialize some registers and iounmap it.

> diff --git a/drivers/usb/host/xhci-mvebu.h b/drivers/usb/host/xhci-mvebu.h
> new file mode 100644
> index 000000000000..897ef298f22f
> --- /dev/null
> +++ b/drivers/usb/host/xhci-mvebu.h
> @@ -0,0 +1,21 @@
> +/*
> + * Copyright (C) 2014 Marvell
> + *
> + * Gregory Clement <gregory.clement@free-electrons.com>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#ifndef __LINUX_XHCI_MVEBU_H
> +#define __LINUX_XHCI_MVEBU_H
> +
> +#ifdef CONFIG_USB_XHCI_MVEBU
> +int xhci_mvebu_probe(struct platform_device *pdev);
> +int xhci_mvebu_remove(struct platform_device *pdev);
> +#else
> +#define xhci_mvebu_probe NULL
> +#define xhci_mvebu_remove NULL
> +#endif
> +#endif /* __LINUX_XHCI_MVEBU_H */
> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> index 8029cc82edc4..f1261d3848a9 100644
> --- a/drivers/usb/host/xhci-plat.c
> +++ b/drivers/usb/host/xhci-plat.c
> @@ -19,6 +19,7 @@
> #include <linux/of_device.h>
>
> #include "xhci.h"
> +#include "xhci-mvebu.h"
>
> static void xhci_plat_quirks(struct device *dev, struct xhci_hcd *xhci)
> {
> @@ -250,6 +251,11 @@ static const struct dev_pm_ops xhci_plat_pm_ops = {
> #endif /* CONFIG_PM */
>
> #ifdef CONFIG_OF
> +struct xhci_plat_ops xhci_plat_mvebu = {
> + .probe = xhci_mvebu_probe,
> + .remove = xhci_mvebu_remove,
> +};

instead, just pass a flag such as:

XHCI_PLAT_MVEBU_MBUS_INIT_QUIRK or something

--
balbi
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