Re: [PATCH v2 14/18] ARM: mvebu: Add support for USB cluster on the Armada 375 SoC

[Felipe Balbi]

On Fri, Apr 25, 2014 at 06:07:05PM +0200, Andrew Lunn wrote:
> On Fri, Apr 25, 2014 at 04:07:12PM +0200, Gregory CLEMENT wrote:
> > The Armada 375 SoC comes with an USB2 host and device controller and
> > an USB3 controller. The USB cluster control register allows to manage
> > common features of both USB controllers.
> > 
> > Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
> > ---
> >  arch/arm/mach-mvebu/Makefile      |  2 +-
> >  arch/arm/mach-mvebu/usb-cluster.c | 96 +++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 97 insertions(+), 1 deletion(-)
> >  create mode 100644 arch/arm/mach-mvebu/usb-cluster.c
> > 
> > diff --git a/arch/arm/mach-mvebu/Makefile b/arch/arm/mach-mvebu/Makefile
> > index a63e43b6b451..dec05e7e1802 100644
> > --- a/arch/arm/mach-mvebu/Makefile
> > +++ b/arch/arm/mach-mvebu/Makefile
> > @@ -4,7 +4,7 @@ ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/$(src)/include \
> >  AFLAGS_coherency_ll.o		:= -Wa,-march=armv7-a
> >  
> >  obj-y				 += system-controller.o mvebu-soc-id.o
> > -obj-$(CONFIG_MACH_MVEBU_V7)      += board-v7.o
> > +obj-$(CONFIG_MACH_MVEBU_V7)      += board-v7.o usb-cluster.o
> >  obj-$(CONFIG_MACH_DOVE)		 += dove.o
> >  obj-$(CONFIG_ARCH_MVEBU)	 += coherency.o coherency_ll.o pmsu.o
> >  obj-$(CONFIG_SMP)                += platsmp.o headsmp.o
> > diff --git a/arch/arm/mach-mvebu/usb-cluster.c b/arch/arm/mach-mvebu/usb-cluster.c
> > new file mode 100644
> > index 000000000000..4c15d282db23
> > --- /dev/null
> > +++ b/arch/arm/mach-mvebu/usb-cluster.c
> > @@ -0,0 +1,96 @@
> > +/*
> > + * USB cluster support for Armada 375 platform.
> > + *
> > + * Copyright (C) 2014 Marvell
> > + *
> > + * Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
> > + *
> > + * 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.
> > + *
> > + * Armada 375 comes with an USB2 host and device controller and an
> > + * USB3 controller. The USB cluster control register allows to manage
> > + * common features of both USB controller.
> > + */
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/init.h>
> > +#include <linux/of_address.h>
> > +#include <linux/io.h>
> > +#include <linux/slab.h>
> > +
> > +#define USB2_PHY_CONFIG_ENABLE BIT(0) /* active low */
> > +
> > +static struct of_device_id of_usb_cluster_table[] = {
> > +	{ .compatible = "marvell,armada-375-usb-cluster", },
> > +	{ /* end of list */ },
> > +};
> > +
> > +static int __init mvebu_usb_cluster_init(void)
> > +{
> > +	struct device_node *np;
> > +
> > +	np = of_find_matching_node(NULL, of_usb_cluster_table);
> > +	if (np) {
> > +		void __iomem *usb_cluster_base;
> > +		u32 reg;
> > +		struct device_node *ehci_node, *xhci_node;
> > +		struct property *ehci_status;
> > +		bool use_usb3 = false;
> > +
> > +		usb_cluster_base = of_iomap(np, 0);
> > +		BUG_ON(!usb_cluster_base);
> > +
> > +		xhci_node = of_find_compatible_node(NULL, NULL,
> > +						"marvell,armada-375-xhci");
> > +
> > +		if (xhci_node && of_device_is_available(xhci_node))
> > +			use_usb3 = true;
> > +
> > +		ehci_node = of_find_compatible_node(NULL, NULL,
> > +						"marvell,orion-ehci");
> > +
> > +		if (ehci_node && of_device_is_available(ehci_node)
> > +			&& use_usb3) {
> > +			/*
> > +			 * We can't use usb2 and usb3 in the same time, so let's
> > +			 * disbale usb2 and complain about it to the user askinf
> > +			 * to fix the device tree.
> > +			 */
> > +
> > +			ehci_status = kzalloc(sizeof(struct property),
> > +					GFP_KERNEL);
> > +			WARN_ON(!ehci_status);
> > +
> > +			ehci_status->value = kstrdup("disabled", GFP_KERNEL);
> > +			WARN_ON(!ehci_status->value);
> > +
> > +			ehci_status->length = 8;
> > +			ehci_status->name = kstrdup("status", GFP_KERNEL);
> > +			WARN_ON(!ehci_status->name);
> > +
> > +			of_update_property(ehci_node, ehci_status);
> > +			pr_err("%s: armada-375-xhci and orion-ehci are incompatible for this SoC.\n",
> > +				__func__);
> > +			pr_err("Please fix your dts!\n");
> > +			pr_err("orion-ehci have been disabled by default...\n");
> > +
> > +		}
> > +
> > +		reg = readl(usb_cluster_base);
> > +		if (use_usb3)
> > +			reg |= USB2_PHY_CONFIG_ENABLE;
> > +		else
> > +			reg &= ~USB2_PHY_CONFIG_ENABLE;
> > +		writel(reg, usb_cluster_base);
> 
> Am i right in saying this in the end is about enabling the USB2 phy or
> a USB3 why? So why not just implement a phy driver?

+1 we have a generic phy layer (drivers/phy) for that.

-- 
balbi

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