Re: [PATCH 1/5] phy: add support for USB cluster on the Armada 375 SoC

From: Gregory CLEMENT
Date: Fri May 23 2014 - 17:51:12 EST


On 23/05/2014 11:20, Kishon Vijay Abraham I wrote:
> Hi,
>
> On Friday 16 May 2014 09:52 PM, 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.
>>
>> 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 | 140 +++++++++++++++++++++++
>> include/dt-bindings/phy/armada-375-usb-cluster.h | 18 +++
[...]

>> +static struct phy_ops armada375_usb_phy_ops = {
>> + .init = armada375_usb_phy_init,
>> + .owner = THIS_MODULE,
>
> nitpick: unnecessary tab.

OK

>> +};
>> +
>> +/*
>> + * Only one controller can use this PHY. We shouldn't have the case
>> + * when two controllers want to use this PHY. But if this case occurs
>> + * then we provide a phy to the first one and return an error for the
>> + * next one. This error has also to be an error returned by
>> + * devm_phy_optional_get() so different from ENODEV for USB2. In the
>> + * USB3 case it still optional and we use ENODEV.
>> + */
>> +static struct phy *armada375_usb_phy_xlate(struct device *dev,
>> + struct of_phandle_args *args)
>> +{
>> + if (WARN_ON(usb_cluster_phy.phy_provided)) {
>> + dev_err(dev, "This PHY has already been provided!\n");
>> + dev_err(dev, "Check your device tree, only one controller can use it\n.");
>> + if (args->args[0] == PHY_USB2)
>> + return ERR_PTR(-EBUSY);
>> + else
>> + return ERR_PTR(-ENODEV);
>> + }
>> +
>> + if (args->args[0] == PHY_USB2)
>> + usb_cluster_phy.use_usb3 = false;
>> + else if (args->args[0] == PHY_USB3)
>> + usb_cluster_phy.use_usb3 = true;
>> + else {
>> + dev_err(dev, "Invalid PHY mode\n");
>> + return ERR_PTR(-ENODEV);
>> + }
>
> how will this behave if there is a phy_put and then a phy_get?

Badly I think :(

I have to think about a better solution then.

>> +
>> + usb_cluster_phy.phy_provided = true;
>> +
>> + return usb_cluster_phy.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 resource *res;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + usb_cluster_base = devm_ioremap_resource(&pdev->dev, res);
>> + if (!usb_cluster_base)
>> + return -ENOMEM;
>> +
>> + phy = devm_phy_create(dev, &armada375_usb_phy_ops, NULL);
>> + if (IS_ERR(phy)) {
>> + dev_err(dev, "failed to create PHY \n");
>> + return PTR_ERR(phy);
>> + }
>> +
>> + usb_cluster_phy.phy = phy;
>> + usb_cluster_phy.reg = usb_cluster_base;
>> + phy_set_drvdata(phy, &usb_cluster_phy);
>> +
>> + 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.clement@xxxxxxxxxxxxxxxxxx>");
>> +MODULE_LICENSE("GPL");
>
> GPL v2?

See the header, I chose "GNU General Public License version 2 or later."
so "GPL" match it.


Thanks for your review, once I will have found a proper solution for the
phy_put/phy_get scenario, I will sent a new version with all the other issues
fixed.


Gregory

>
> Thanks
> Kishon
>


--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/