On 13/05/2014 10:06, Gregory CLEMENT wrote:
> On 13/05/2014 07:53, Kishon Vijay Abraham I wrote:
>> Hi,
>>
>> On Sunday 11 May 2014 11:47 PM, Thomas Petazzoni wrote:
>>> From: Gregory CLEMENT <gregory.clem...@free-electrons.com>
>>>
>>> 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.
>>>
>>> This commit adds a driver integrated in the generic PHY framework to
>>> control this USB cluster feature.
>>>
>>> Signed-off-by: Gregory CLEMENT <gregory.clem...@free-electrons.com>
>>> Signed-off-by: Thomas Petazzoni <thomas.petazz...@free-electrons.com>
>>> ---
>>> drivers/phy/Kconfig | 6 ++
>>> drivers/phy/Makefile | 1 +
>>> drivers/phy/phy-armada375-usb2.c | 157
>>> +++++++++++++++++++++++++++++++++++++++
>>> 3 files changed, 164 insertions(+)
>>> create mode 100644 drivers/phy/phy-armada375-usb2.c
>>>
>>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>>> index 3bb05f1..e63cf9d 100644
>>> --- a/drivers/phy/Kconfig
>>> +++ b/drivers/phy/Kconfig
>>> @@ -15,6 +15,12 @@ config GENERIC_PHY
>>> phy users can obtain reference to the PHY. All the users of this
>>> framework should select this config.
>>>
>>> +config ARMADA375_USBCLUSTER_PHY
>>> + def_bool y
>>> + depends on MACH_ARMADA_375 || COMPILE_TEST
>>> + depends on OF
>>> + select GENERIC_PHY
>>> +
>>> config PHY_EXYNOS_MIPI_VIDEO
>>> tristate "S5P/EXYNOS SoC series MIPI CSI-2/DSI PHY driver"
>>> depends on HAS_IOMEM
>>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>>> index 2faf78e..47d5a86 100644
>>> --- a/drivers/phy/Makefile
>>> +++ b/drivers/phy/Makefile
>>> @@ -3,6 +3,7 @@
>>> #
>>>
>>> obj-$(CONFIG_GENERIC_PHY) += phy-core.o
>>> +obj-$(CONFIG_ARMADA375_USBCLUSTER_PHY) += phy-armada375-usb2.o
>>> obj-$(CONFIG_BCM_KONA_USB2_PHY) += phy-bcm-kona-usb2.o
>>> obj-$(CONFIG_PHY_EXYNOS_DP_VIDEO) += phy-exynos-dp-video.o
>>> obj-$(CONFIG_PHY_EXYNOS_MIPI_VIDEO) += phy-exynos-mipi-video.o
>>> diff --git a/drivers/phy/phy-armada375-usb2.c
>>> b/drivers/phy/phy-armada375-usb2.c
>>> new file mode 100644
>>> index 0000000..a6f746d
>>> --- /dev/null
>>> +++ b/drivers/phy/phy-armada375-usb2.c
>>> @@ -0,0 +1,157 @@
>>> +/*
>>> + * USB cluster support for Armada 375 platform.
>>> + *
>>> + * Copyright (C) 2014 Marvell
>>> + *
>>> + * Gregory CLEMENT <gregory.clem...@free-electrons.com>
>>> + *
>>> + * This file is licensed under the terms of the GNU General Public
>>> + * License version 2 or later. 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 controllers.
>>> + */
>>> +
>>> +#include <linux/init.h>
>>> +#include <linux/io.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of_address.h>
>>> +#include <linux/phy/phy.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/slab.h>
>>> +
>>> +#define USB2_PHY_CONFIG_DISABLE BIT(0)
>>> +
>>> +/* The USB cluster allows to choose between two PHYs */
>>> +#define NB_PHY 2
>>> +
>>> +enum {
>>> + PHY_USB2 = 0,
>>> + PHY_USB3 = 1,
>>> +};
>>> +
>>> +struct armada375_cluster_phy {
>>> + struct phy *phy;
>>> + void __iomem *reg;
>>> + bool enable;
>>> + bool use_usb3;
>>> +};
>>> +
>>> +struct armada375_cluster_phy usb_cluster_phy[NB_PHY];
>>> +
>>> +static int armada375_usb_phy_init(struct phy *phy)
>>> +{
>>> + struct armada375_cluster_phy *cluster_phy = phy_get_drvdata(phy);
>>> + u32 reg;
>>
>> This function should be protected since both your PHYs use this ops.
>
> Right
Actually only one PHY can access this register. See the probe function,
cluster_phy->enable is only set to true for one PHY.
>
>>> +
>>> + if (!cluster_phy->enable)
>>> + return -ENODEV;
>>> +
>>> + reg = readl(cluster_phy->reg);
>>> + if (cluster_phy->use_usb3)
>>> + reg |= USB2_PHY_CONFIG_DISABLE;
>>> + else
>>> + reg &= ~USB2_PHY_CONFIG_DISABLE;
>>> + writel(reg, cluster_phy->reg);
>>
>> This is confusing since both your PHYs control the same bit?
Same here at the end the bit is accessed by only one PHY.
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static struct phy_ops armada375_usb_phy_ops = {
>>> + .init = armada375_usb_phy_init,
>>> + .owner = THIS_MODULE,
>>> +};
>>> +
>>> +static struct phy *armada375_usb_phy_xlate(struct device *dev,
>>> + struct of_phandle_args *args)
>>> +{
>>> + if (WARN_ON(args->args[0] >= NB_PHY))
>>> + return ERR_PTR(-ENODEV);
>>> +
>>> + return usb_cluster_phy[args->args[0]].phy;
>>> +}
>>> +
>>> +static int armada375_usb_phy_probe(struct platform_device *pdev)
>>> +{
>>> + struct device *dev = &pdev->dev;
>>> + struct phy *phy;
>>> + struct phy_provider *phy_provider;
>>> + void __iomem *usb_cluster_base;
>>> + struct device_node *xhci_node;
>>> + struct resource *res;
>>> + int i;
>>> +
>>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> + usb_cluster_base = devm_ioremap_resource(&pdev->dev, res);
>>> + if (!usb_cluster_base)
>>> + return -ENOMEM;
>>> +
>>> + for (i = 0; i < NB_PHY; i++) {
>>
>> For devices which have multiple PHYs, each PHY should be modelled as the
>> sub-node of the *PHY provider* device node.
>
> Actually it is the opposite the same PHY is shared between the EHCI
> and the xHCI controllers. It is more a PHY muxer than a PHY itself.
>
> I had to create 2 logical PHYs because once the phy_init() is called
> by a USB driver then the .init ops is not called anymore by the next
> call to phy_init(). One of the goal of this is to disable a port for
> the USB controller which can't use it due to the configuration of the
> USB cluster.
>
> But I can see how to make this two "pseudo" PHYs sub-node of the *PHY
> provider* device node. It shouldn't change the internal logic of this
> driver.
I need to make a distinction when the PHY access by the xHCI or when
it was access by the EHCI. If I create two new sub-node then I will
also need to add a property to make this distinction. It seems a little
overkill for the need.
>
>
>>> + phy = devm_phy_create(dev, &armada375_usb_phy_ops, NULL);
>>> + if (IS_ERR(phy)) {
>>> + dev_err(dev, "failed to create PHY n%d\n", i);
>>> + return PTR_ERR(phy);
>>> + }
>>> +
>>> + usb_cluster_phy[i].phy = phy;
>>> + usb_cluster_phy[i].reg = usb_cluster_base;
>>> + usb_cluster_phy[i].enable = false;
>>> + phy_set_drvdata(phy, &usb_cluster_phy[i]);
>>> + }
>>> +
>>> + usb_cluster_phy[PHY_USB2].use_usb3 = false;
>>> + usb_cluster_phy[PHY_USB3].use_usb3 = true;
>>> +
>>> + /*
>>> + * We can't use the first usb2 unit and usb3 at the same time
>>> + * to manage a USB2 device, so let's disable usb2 if usb3 is
>>> + * selected. In this case the USB2 device will be managed by
>>> + * the xhci controller.
>>> + */
>>> +
>>> + xhci_node = of_find_compatible_node(NULL, NULL,
>>> + "marvell,armada-375-xhci");
>>
>> huh.. that's too much binding between the controller and the PHY.
>>
>
> That's why initially it was not part of the PHY framework. The USB
> cluster is really a part managing common feature between the USB
> controllers which are part of the Armada 375 SoC.
>
> However the initial version was not really good, because this piece of
> code was located in the mach- directory whereas we are trying to move
> most of the files out of this directory now. The USB cluster is not a
> real PHY as it is related to the PHY management this framework remains
> the best place for it.
>
>>> +
>>> + if (xhci_node && of_device_is_available(xhci_node)) {
>>> + usb_cluster_phy[PHY_USB3].enable = true;
>>> + } else {
>>> + struct device_node *ehci_node;
>>> + ehci_node = of_find_compatible_node(NULL, NULL,
>>> + "marvell,orion-ehci");
>>> + if (ehci_node && of_device_is_available(ehci_node))
>>> + usb_cluster_phy[PHY_USB2].enable = true;
>>> + of_node_put(ehci_node);
>>> + }
>>> +
>>> + of_node_put(xhci_node);
>>> +
>>> + phy_provider = devm_of_phy_provider_register(&pdev->dev,
>>> + armada375_usb_phy_xlate);
>>> + if (IS_ERR(phy_provider))
>>> + return PTR_ERR(phy_provider);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static const struct of_device_id of_usb_cluster_table[] = {
>>> + { .compatible = "marvell,armada-375-usb-cluster", },
>>> + { /* end of list */ },
>>> +};
>>> +MODULE_DEVICE_TABLE(of, of_usb_cluster_table);
>>> +
>>> +static struct platform_driver armada375_usb_phy_driver = {
>>> + .probe = armada375_usb_phy_probe,
>>> + .driver = {
>>> + .of_match_table = of_usb_cluster_table,
>>> + .name = "armada-375-usb-cluster",
>>> + .owner = THIS_MODULE,
>>> + }
>>> +};
>>> +module_platform_driver(armada375_usb_phy_driver);
>>> +
>>> +MODULE_DESCRIPTION("Armada 375 USB cluster driver");
>>> +MODULE_AUTHOR("Gregory CLEMENT <gregory.clem...@free-electrons.com>");
>>> +MODULE_LICENSE("GPL");
>>
>> GPL v2?
>
> No it is really GPL v2 or latter as written at the top of this file
>
>
> Thanks,
>
> Gregory
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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