On 14/05/2014 16:27, Kishon Vijay Abraham I wrote:
> Hi,
>
> On Tuesday 13 May 2014 03:11 PM, Gregory CLEMENT wrote:
>> 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.clement@xxxxxxxxxxxxxxxxxx>
>>>>>
>>>>> 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.clement@xxxxxxxxxxxxxxxxxx>
>>>>> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
>>>>> ---
>>>>> 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.clement@xxxxxxxxxxxxxxxxxx>
>>>>> + *
>>>>> + * 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.
>
> Alright, so you have a single PHY that can be used by either XHCI or EHCI? And
> the use of PHY is mutually exclusive? How should it behave if you have both
> XHCI and EHCI?
if we have both XHCI and EHCI then it is the USB2_PHY_CONFIG_DISABLE which
determine which one is used. By default we decide to select the XHCI.
>
> One way to configure the PHY to a particular mode is by passing it as phandle
> arguments. I think you can use that to enable or disable USB2_PHY_CONFIG_DISABLE?
actually it was more or less what I do:
for the XHCI I use:
phys = <&usbcluster 1>;
which enable the USB2_PHY_CONFIG_DISABLE
for the EHCI I use phys = <&usbcluster 0>;
which disable the USB2_PHY_CONFIG_DISABLE
If I had to create two PHY it was because of the behavior of
phy_init(). I need to be able to disable a controller if it can't use
the PHY. For this purpose my ops->init() exits in error. However
phy_init() will call ops->init() only one time, then the internal
counter init_count will be incremented, and the next call to phy_init
will skip the call to ops->init. And the behavior is the same for
phy_power_on().
So given this I don't see how to do in an other way except by
modifying the value of the counter in my ops.
Thanks,
Gregory
>
> Thanks
> Kishon
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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