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SubjectRE: [PATCH v10 5/6] usb:cdns3 Add Cadence USB3 DRD Driver
Date
>
>On 11/08/2019 14:59, Pawel Laszczak wrote:
>> Hi,
>>
>>>
>>> On 21/07/2019 21:32, Pawel Laszczak wrote:
>>>> This patch introduce new Cadence USBSS DRD driver to Linux kernel.
>>>>
>>>> The Cadence USBSS DRD Controller is a highly configurable IP Core which
>>>> can be instantiated as Dual-Role Device (DRD), Peripheral Only and
>>>> Host Only (XHCI)configurations.
>>>>
>>>> The current driver has been validated with FPGA platform. We have
>>>> support for PCIe bus, which is used on FPGA prototyping.
>>>>
>>>> The host side of USBSS-DRD controller is compliant with XHCI
>>>> specification, so it works with standard XHCI Linux driver.
>>>>
>>>> Signed-off-by: Pawel Laszczak <pawell@cadence.com>
>>>> ---
>>>> drivers/usb/Kconfig | 2 +
>>>> drivers/usb/Makefile | 2 +
>>>> drivers/usb/cdns3/Kconfig | 46 +
>>>> drivers/usb/cdns3/Makefile | 17 +
>>>> drivers/usb/cdns3/cdns3-pci-wrap.c | 203 +++
>>>> drivers/usb/cdns3/core.c | 554 +++++++
>>>> drivers/usb/cdns3/core.h | 109 ++
>>>> drivers/usb/cdns3/debug.h | 171 ++
>>>> drivers/usb/cdns3/debugfs.c | 87 ++
>>>> drivers/usb/cdns3/drd.c | 390 +++++
>>>> drivers/usb/cdns3/drd.h | 166 ++
>>>> drivers/usb/cdns3/ep0.c | 914 +++++++++++
>>>> drivers/usb/cdns3/gadget-export.h | 28 +
>>>> drivers/usb/cdns3/gadget.c | 2338 ++++++++++++++++++++++++++++
>>>> drivers/usb/cdns3/gadget.h | 1321 ++++++++++++++++
>>>> drivers/usb/cdns3/host-export.h | 28 +
>>>> drivers/usb/cdns3/host.c | 71 +
>>>> drivers/usb/cdns3/trace.c | 11 +
>>>> drivers/usb/cdns3/trace.h | 493 ++++++
>>>> 19 files changed, 6951 insertions(+)
>>>> create mode 100644 drivers/usb/cdns3/Kconfig
>>>> create mode 100644 drivers/usb/cdns3/Makefile
>>>> create mode 100644 drivers/usb/cdns3/cdns3-pci-wrap.c
>>>> create mode 100644 drivers/usb/cdns3/core.c
>>>> create mode 100644 drivers/usb/cdns3/core.h
>>>> create mode 100644 drivers/usb/cdns3/debug.h
>>>> create mode 100644 drivers/usb/cdns3/debugfs.c
>>>> create mode 100644 drivers/usb/cdns3/drd.c
>>>> create mode 100644 drivers/usb/cdns3/drd.h
>>>> create mode 100644 drivers/usb/cdns3/ep0.c
>>>> create mode 100644 drivers/usb/cdns3/gadget-export.h
>>>> create mode 100644 drivers/usb/cdns3/gadget.c
>>>> create mode 100644 drivers/usb/cdns3/gadget.h
>>>> create mode 100644 drivers/usb/cdns3/host-export.h
>>>> create mode 100644 drivers/usb/cdns3/host.c
>>>> create mode 100644 drivers/usb/cdns3/trace.c
>>>> create mode 100644 drivers/usb/cdns3/trace.h
>>>>
>
><snip>
>
>>>
>>>> diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
>>>> new file mode 100644
>>>> index 000000000000..291f08be56fe
>>>> --- /dev/null
>>>> +++ b/drivers/usb/cdns3/gadget.c
>>>> @@ -0,0 +1,2338 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +/*
>>>> + * Cadence USBSS DRD Driver - gadget side.
>>>> + *
>>>> + * Copyright (C) 2018-2019 Cadence Design Systems.
>>>> + * Copyright (C) 2017-2018 NXP
>>>> + *
>>>> + * Authors: Pawel Jez <pjez@cadence.com>,
>>>> + * Pawel Laszczak <pawell@cadence.com>
>>>> + * Peter Chen <peter.chen@nxp.com>
>>>> + */
>>>> +
>>>
>>> <snip>
>>>
>>>> +/**
>>>> + * cdns3_device_irq_handler- interrupt handler for device part of controller
>>>> + *
>>>> + * @irq: irq number for cdns3 core device
>>>> + * @data: structure of cdns3
>>>> + *
>>>> + * Returns IRQ_HANDLED or IRQ_NONE
>>>> + */
>>>> +static irqreturn_t cdns3_device_irq_handler(int irq, void *data)
>>>> +{
>>>> + struct cdns3_device *priv_dev;
>>>> + struct cdns3 *cdns = data;
>>>> + irqreturn_t ret = IRQ_NONE;
>>>> + unsigned long flags;
>>>> + u32 reg;
>>>> +
>>>> + priv_dev = cdns->gadget_dev;
>>>> + spin_lock_irqsave(&priv_dev->lock, flags);
>>>> +
>>>> + /* check USB device interrupt */
>>>> + reg = readl(&priv_dev->regs->usb_ists);
>>>> +
>>>> + if (reg) {
>>>> + writel(reg, &priv_dev->regs->usb_ists);
>>>
>>> Do we need to mask device interrupts till thread handler has done processing
>>> current set of events?
>>
>> Yes, we need do this to avoid raising the next the same interrupts.
>> If we return back from hard irq handler without clearing reported interrupts,
>> then system report them again. The solution for this is to use IRQF_ONESHOT
>> flag during registering interrupt, but I can't use this flag
>> because I have shared interrupt line with other component.
>>
>> In this version these (usb_ists) interrupts are handled in hard irq, but in next version
>> will be moved to thread handler.
>>
>>>> + cdns3_check_usb_interrupt_proceed(priv_dev, reg);
>>>> + ret = IRQ_HANDLED;
>>>> + }
>>>> +
>>>> + /* check endpoint interrupt */
>>>> + reg = readl(&priv_dev->regs->ep_ists);
>>>> +
>>>> + if (reg) {
>>>> + priv_dev->shadow_ep_en |= reg;
>>>> + reg = ~reg & readl(&priv_dev->regs->ep_ien);
>>>> + /* mask deferred interrupt. */
>>>> + writel(reg, &priv_dev->regs->ep_ien);
>>>> + ret = IRQ_WAKE_THREAD;
>>>> + }
>>>> +
>>>> + spin_unlock_irqrestore(&priv_dev->lock, flags);
>>>> + return ret;
>>>> +}
>>>> +
>>>
>>> <snip>
>>>
>>>> +
>>>> +static int cdns3_gadget_start(struct cdns3 *cdns)
>>>> +{
>>>> + struct cdns3_device *priv_dev;
>>>> + u32 max_speed;
>>>> + int ret;
>>>> +
>>>> + priv_dev = kzalloc(sizeof(*priv_dev), GFP_KERNEL);
>>>> + if (!priv_dev)
>>>> + return -ENOMEM;
>>>> +
>>>> + cdns->gadget_dev = priv_dev;
>>>> + priv_dev->sysdev = cdns->dev;
>>>> + priv_dev->dev = cdns->dev;
>>>> + priv_dev->regs = cdns->dev_regs;
>>>> +
>>>> + device_property_read_u16(priv_dev->dev, "cdns,on-chip-buff-size",
>>>> + &priv_dev->onchip_buffers);
>>>> +
>>>> + if (priv_dev->onchip_buffers <= 0) {
>>>> + u32 reg = readl(&priv_dev->regs->usb_cap2);
>>>> +
>>>> + priv_dev->onchip_buffers = USB_CAP2_ACTUAL_MEM_SIZE(reg);
>>>> + }
>>>> +
>>>> + if (!priv_dev->onchip_buffers)
>>>> + priv_dev->onchip_buffers = 256;
>>>> +
>>>> + max_speed = usb_get_maximum_speed(cdns->dev);
>>>> +
>>>> + /* Check the maximum_speed parameter */
>>>> + switch (max_speed) {
>>>> + case USB_SPEED_FULL:
>>>
>>> In this case we need to limit controller max speed to full-speed as system
>>> integrator would expect that. e.g. in DT node, maximum-speed = "full-speed";
>>>
>>> I suppose we need to set the force Full-speed bit here?
>>>
>>>> + case USB_SPEED_HIGH:
>>>
>>> Here we need to restrict device controller max-speed to high-speed.
>>>
>>
>> Why system integrator would limit the speed of controller?
>
>To save cost? For many use cases, high-speed is more then sufficient.
>

I think I know what you mean.

I've add such functionality to next version.


>> For debugging purpose it's ok, but in production system it's better
>> to use higher speed.
>> Do we relay need such functionality ?
>
>Mostly for testing purpose. I can just change the DT node's speed property
>to the lower speed to limit the controller to that speed.
>
>If we can achieve that with a few lines of code, why not support it?
>
>>
>>>> + case USB_SPEED_SUPER:
>>>> + break;
>>>> + default:
>>>> + dev_err(cdns->dev, "invalid maximum_speed parameter %d\n",
>>>> + max_speed);
>>>> + /* fall through */
>>>> + case USB_SPEED_UNKNOWN:
>>>> + /* default to superspeed */
>>>> + max_speed = USB_SPEED_SUPER;
>>>> + break;
>>>> + }
>>>> +
>>>> + /* fill gadget fields */
>>>> + priv_dev->gadget.max_speed = max_speed;
>>>> + priv_dev->gadget.speed = USB_SPEED_UNKNOWN;
>>>> + priv_dev->gadget.ops = &cdns3_gadget_ops;
>>>> + priv_dev->gadget.name = "usb-ss-gadget";
>>>> + priv_dev->gadget.sg_supported = 1;
>>>> +
>>>> + spin_lock_init(&priv_dev->lock);
>>>> + INIT_WORK(&priv_dev->pending_status_wq,
>>>> + cdns3_pending_setup_status_handler);
>>>> +
>>>> + /* initialize endpoint container */
>>>> + INIT_LIST_HEAD(&priv_dev->gadget.ep_list);
>>>> + INIT_LIST_HEAD(&priv_dev->aligned_buf_list);
>>>> +
>>>> + ret = cdns3_init_eps(priv_dev);
>>>> + if (ret) {
>>>> + dev_err(priv_dev->dev, "Failed to create endpoints\n");
>>>> + goto err1;
>>>> + }
>>>> +
>>>> + /* allocate memory for setup packet buffer */
>>>> + priv_dev->setup_buf = dma_alloc_coherent(priv_dev->sysdev, 8,
>>>> + &priv_dev->setup_dma, GFP_DMA);
>>>> + if (!priv_dev->setup_buf) {
>>>> + ret = -ENOMEM;
>>>> + goto err2;
>>>> + }
>>>> +
>>>> + priv_dev->dev_ver = readl(&priv_dev->regs->usb_cap6);
>>>> +
>>>> + dev_dbg(priv_dev->dev, "Device Controller version: %08x\n",
>>>> + readl(&priv_dev->regs->usb_cap6));
>>>> + dev_dbg(priv_dev->dev, "USB Capabilities:: %08x\n",
>>>> + readl(&priv_dev->regs->usb_cap1));
>>>> + dev_dbg(priv_dev->dev, "On-Chip memory cnfiguration: %08x\n",
>>>> + readl(&priv_dev->regs->usb_cap2));
>>>> +
>>>> + priv_dev->dev_ver = GET_DEV_BASE_VERSION(priv_dev->dev_ver);
>>>> +
>>>> + priv_dev->zlp_buf = kzalloc(CDNS3_EP_ZLP_BUF_SIZE, GFP_KERNEL);
>>>> + if (!priv_dev->zlp_buf) {
>>>> + ret = -ENOMEM;
>>>> + goto err3;
>>>> + }
>>>> +
>>>> + /* add USB gadget device */
>>>> + ret = usb_add_gadget_udc(priv_dev->dev, &priv_dev->gadget);
>>>> + if (ret < 0) {
>>>> + dev_err(priv_dev->dev,
>>>> + "Failed to register USB device controller\n");
>>>> + goto err4;
>>>> + }
>>>> +
>>>> + return 0;
>>>> +err4:
>>>> + kfree(priv_dev->zlp_buf);
>>>> +err3:
>>>> + dma_free_coherent(priv_dev->sysdev, 8, priv_dev->setup_buf,
>>>> + priv_dev->setup_dma);
>>>> +err2:
>>>> + cdns3_free_all_eps(priv_dev);
>>>> +err1:
>>>> + cdns->gadget_dev = NULL;
>>>> + return ret;
>>>> +}
>>>> +
>>>
>
--
pawell
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