On 07/03/2019 07:37, Pawel Laszczak wrote:

Hi,

quoted

Pawel,

On 14/02/2019 21:45, Pawel Laszczak wrote:

quoted

This patch introduce new Cadence USBSS DRD driver to linux kernel.

The Cadence USBSS DRD Driver is a highly configurable IP Core whichi
can be instantiated as Dual-Role Device (DRD), Peripheral Only and
Host Only (XHCI)configurations.

The current driver has been validated with FPGA burned. We have support
for PCIe bus, which is used on FPGA prototyping.

The host side of USBSS-DRD controller is compliance 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          |   44 +
 drivers/usb/cdns3/Makefile         |   14 +
 drivers/usb/cdns3/cdns3-pci-wrap.c |  155 +++
 drivers/usb/cdns3/core.c           |  403 ++++++
 drivers/usb/cdns3/core.h           |  116 ++
 drivers/usb/cdns3/debug.h          |  168 +++
 drivers/usb/cdns3/debugfs.c        |  164 +++
 drivers/usb/cdns3/drd.c            |  365 +++++
 drivers/usb/cdns3/drd.h            |  162 +++
 drivers/usb/cdns3/ep0.c            |  907 +++++++++++++
 drivers/usb/cdns3/gadget-export.h  |   28 +
 drivers/usb/cdns3/gadget.c         | 2003 ++++++++++++++++++++++++++++
 drivers/usb/cdns3/gadget.h         | 1207 +++++++++++++++++
 drivers/usb/cdns3/host-export.h    |   28 +
 drivers/usb/cdns3/host.c           |   72 +
 drivers/usb/cdns3/trace.c          |   23 +
 drivers/usb/cdns3/trace.h          |  404 ++++++
 19 files changed, 6267 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

diff --git a/drivers/usb/Kconfig b/drivers/usb/Kconfig
index 987fc5ba6321..5f9334019d04 100644
--- a/drivers/usb/Kconfig
+++ b/drivers/usb/Kconfig

@@ -112,6 +112,8 @@ source "drivers/usb/usbip/Kconfig"

 endif

+source "drivers/usb/cdns3/Kconfig"
+
 source "drivers/usb/mtu3/Kconfig"

 source "drivers/usb/musb/Kconfig"

diff --git a/drivers/usb/Makefile b/drivers/usb/Makefile
index 7d1b8c82b208..ab125b966cac 100644
--- a/drivers/usb/Makefile
+++ b/drivers/usb/Makefile

@@ -12,6 +12,8 @@ obj-$(CONFIG_USB_DWC3)		+= dwc3/
 obj-$(CONFIG_USB_DWC2)		+= dwc2/
 obj-$(CONFIG_USB_ISP1760)	+= isp1760/

+obj-$(CONFIG_USB_CDNS3)		+= cdns3/
+
 obj-$(CONFIG_USB_MON)		+= mon/
 obj-$(CONFIG_USB_MTU3)		+= mtu3/

diff --git a/drivers/usb/cdns3/Kconfig b/drivers/usb/cdns3/Kconfig
new file mode 100644
index 000000000000..27cb3d8dbe3d
--- /dev/null
+++ b/drivers/usb/cdns3/Kconfig

@@ -0,0 +1,44 @@
+config USB_CDNS3
+	tristate "Cadence USB3 Dual-Role Controller"
+	depends on USB_SUPPORT && (USB || USB_GADGET) && HAS_DMA
+	help
+	  Say Y here if your system has a cadence USB3 dual-role controller.
+	  It supports: dual-role switch, Host-only, and Peripheral-only.
+
+	  If you choose to build this driver is a dynamically linked
+	  as module, the module will be called cdns3.ko.
+
+if USB_CDNS3
+
+config USB_CDNS3_GADGET
+        bool "Cadence USB3 device controller"
+        depends on USB_GADGET
+        help
+          Say Y here to enable device controller functionality of the
+          cadence USBSS-DEV driver.

"Cadence" ?

quoted

+
+          This controller supports FF, HS and SS mode. It doesn't support
+          LS and SSP mode.
+
+config USB_CDNS3_HOST
+        bool "Cadence USB3 host controller"
+        depends on USB_XHCI_HCD
+        help
+          Say Y here to enable host controller functionality of the
+          cadence driver.
+
+          Host controller is compliant with XHCI so it will use
+          standard XHCI driver.
+
+config USB_CDNS3_PCI_WRAP
+	tristate "Cadence USB3 support on PCIe-based platforms"
+	depends on USB_PCI && ACPI
+	default USB_CDNS3
+	help
+	  If you're using the USBSS Core IP with a PCIe, please say
+	  'Y' or 'M' here.
+
+	  If you choose to build this driver as module it will
+	  be dynamically linked and module will be called cdns3-pci.ko
+
+endif

diff --git a/drivers/usb/cdns3/Makefile b/drivers/usb/cdns3/Makefile
new file mode 100644
index 000000000000..8f9438593375
--- /dev/null
+++ b/drivers/usb/cdns3/Makefile

@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0
+# define_trace.h needs to know how to find our header
+CFLAGS_trace.o				:= -I$(src)
+
+cdns3-y					:= core.o drd.o trace.o
+
+obj-$(CONFIG_USB_CDNS3)			+= cdns3.o
+ifneq ($(CONFIG_DEBUG_FS),)
+	cdns3-y				+= debugfs.o
+endif
+
+cdns3-$(CONFIG_USB_CDNS3_GADGET)	+= gadget.o ep0.o
+cdns3-$(CONFIG_USB_CDNS3_HOST)		+= host.o
+obj-$(CONFIG_USB_CDNS3_PCI_WRAP)	+= cdns3-pci-wrap.o

diff --git a/drivers/usb/cdns3/cdns3-pci-wrap.c b/drivers/usb/cdns3/cdns3-pci-wrap.c
new file mode 100644
index 000000000000..d0b2d3d9b983
--- /dev/null
+++ b/drivers/usb/cdns3/cdns3-pci-wrap.c

@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cadence USBSS PCI Glue driver
+ *
+ * Copyright (C) 2018 Cadence.

2018-2019?

quoted

+ *
+ * Author: Pawel Laszczak [off-list ref]
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+
+struct cdns3_wrap {
+	struct platform_device *plat_dev;
+	struct pci_dev *hg_dev;
+	struct resource dev_res[4];
+};
+
+struct cdns3_wrap wrap;
+
+#define RES_IRQ_ID		0
+#define RES_HOST_ID		1
+#define RES_DEV_ID		2
+#define RES_DRD_ID		3
+
+#define PCI_BAR_HOST		0
+#define PCI_BAR_DEV		2
+#define PCI_BAR_OTG		4
+
+#define PCI_DEV_FN_HOST_DEVICE	0
+#define PCI_DEV_FN_OTG		1
+
+#define PCI_DRIVER_NAME		"cdns3-pci-usbss"
+#define PLAT_DRIVER_NAME	"cdns-usb3"
+
+#define CDNS_VENDOR_ID 0x17cd
+#define CDNS_DEVICE_ID 0x0100
+
+/**
+ * cdns3_pci_probe - Probe function for Cadence USB wrapper driver
+ * @pdev: platform device object
+ * @id: pci device id
+ *
+ * Returns 0 on success otherwise negative errno
+ */
+static int cdns3_pci_probe(struct pci_dev *pdev,
+			   const struct pci_device_id *id)
+{
+	struct platform_device_info plat_info;
+	struct cdns3_wrap *wrap;
+	struct resource *res;
+	int err;
+
+	/*
+	 * for GADGET/HOST PCI (devfn) function number is 0,
+	 * for OTG PCI (devfn) function number is 1
+	 */
+	if (!id || pdev->devfn != PCI_DEV_FN_HOST_DEVICE)
+		return -EINVAL;
+
+	err = pcim_enable_device(pdev);
+	if (err) {
+		dev_err(&pdev->dev, "Enabling PCI device has failed %d\n", err);
+		return err;
+	}
+
+	pci_set_master(pdev);
+	wrap = devm_kzalloc(&pdev->dev, sizeof(*wrap), GFP_KERNEL);
+	if (!wrap) {
+		dev_err(&pdev->dev, "Failed to allocate memory\n");
+		return -ENOMEM;
+	}
+
+	/* function 0: host(BAR_0) + device(BAR_1) + otg(BAR_2)). */
+	memset(wrap->dev_res, 0x00,
+	       sizeof(struct resource) * ARRAY_SIZE(wrap->dev_res));
+	dev_dbg(&pdev->dev, "Initialize Device resources\n");
+	res = wrap->dev_res;
+
+	res[RES_DEV_ID].start = pci_resource_start(pdev, PCI_BAR_DEV);
+	res[RES_DEV_ID].end =   pci_resource_end(pdev, PCI_BAR_DEV);
+	res[RES_DEV_ID].name = "dev";
+	res[RES_DEV_ID].flags = IORESOURCE_MEM;
+	dev_dbg(&pdev->dev, "USBSS-DEV physical base addr: %pa\n",
+		&res[RES_DEV_ID].start);
+
+	res[RES_HOST_ID].start = pci_resource_start(pdev, PCI_BAR_HOST);
+	res[RES_HOST_ID].end = pci_resource_end(pdev, PCI_BAR_HOST);
+	res[RES_HOST_ID].name = "xhci";
+	res[RES_HOST_ID].flags = IORESOURCE_MEM;
+	dev_dbg(&pdev->dev, "USBSS-XHCI physical base addr: %pa\n",
+		&res[RES_HOST_ID].start);
+
+	res[RES_DRD_ID].start = pci_resource_start(pdev, PCI_BAR_OTG);
+	res[RES_DRD_ID].end =   pci_resource_end(pdev, PCI_BAR_OTG);
+	res[RES_DRD_ID].name = "otg";
+	res[RES_DRD_ID].flags = IORESOURCE_MEM;
+	dev_dbg(&pdev->dev, "USBSS-DRD physical base addr: %pa\n",
+		&res[RES_DRD_ID].start);
+
+	/* Interrupt common for both device and XHCI */
+	wrap->dev_res[RES_IRQ_ID].start = pdev->irq;
+	wrap->dev_res[RES_IRQ_ID].name = "cdns3-irq";
+	wrap->dev_res[RES_IRQ_ID].flags = IORESOURCE_IRQ;
+
+	/* set up platform device info */
+	memset(&plat_info, 0, sizeof(plat_info));
+	plat_info.parent = &pdev->dev;
+	plat_info.fwnode = pdev->dev.fwnode;
+	plat_info.name = PLAT_DRIVER_NAME;
+	plat_info.id = pdev->devfn;
+	plat_info.res = wrap->dev_res;
+	plat_info.num_res = ARRAY_SIZE(wrap->dev_res);
+	plat_info.dma_mask = pdev->dma_mask;
+
+	/* register platform device */
+	wrap->plat_dev = platform_device_register_full(&plat_info);
+	if (IS_ERR(wrap->plat_dev))
+		return PTR_ERR(wrap->plat_dev);
+
+	pci_set_drvdata(pdev, wrap);
+
+	return err;
+}
+
+void cdns3_pci_remove(struct pci_dev *pdev)
+{
+	struct cdns3_wrap *wrap = (struct cdns3_wrap *)pci_get_drvdata(pdev);
+
+	platform_device_unregister(wrap->plat_dev);
+}
+
+static const struct pci_device_id cdns3_pci_ids[] = {
+	{ PCI_DEVICE(CDNS_VENDOR_ID, CDNS_DEVICE_ID), },
+	{ 0, }
+};
+
+static struct pci_driver cdns3_pci_driver = {
+	.name = PCI_DRIVER_NAME,
+	.id_table = cdns3_pci_ids,
+	.probe = cdns3_pci_probe,
+	.remove = cdns3_pci_remove,
+};
+
+module_pci_driver(cdns3_pci_driver);
+MODULE_DEVICE_TABLE(pci, cdns3_pci_ids);
+
+MODULE_AUTHOR("Pawel Laszczak [off-list ref]");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Cadence USBSS PCI wrapperr");
+

diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
new file mode 100644
index 000000000000..aa2f63241dab
--- /dev/null
+++ b/drivers/usb/cdns3/core.c

@@ -0,0 +1,403 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cadence USBSS DRD Driver.
+ *
+ * Copyright (C) 2018 Cadence.
+ * Copyright (C) 2017-2018 NXP
+ *
+ * Author: Peter Chen <peter.chen@nxp.com>
+ *         Pawel Laszczak <pawell@cadence.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/pm_runtime.h>
+
+#include "gadget.h"
+#include "core.h"
+#include "host-export.h"
+#include "gadget-export.h"
+#include "drd.h"
+#include "debug.h"
+
+static inline
+struct cdns3_role_driver *cdns3_get_current_role_driver(struct cdns3 *cdns)
+{
+	WARN_ON(cdns->role >= CDNS3_ROLE_END || !cdns->roles[cdns->role]);
+	return cdns->roles[cdns->role];
+}
+
+static int cdns3_role_start(struct cdns3 *cdns, enum cdns3_roles role)
+{
+	int ret;
+
+	if (WARN_ON(role >= CDNS3_ROLE_END))
+		return 0;
+
+	if (!cdns->roles[role])
+		return -ENXIO;
+
+	if (cdns->roles[role]->state == CDNS3_ROLE_STATE_ACTIVE)
+		return 0;
+
+	mutex_lock(&cdns->mutex);
+	cdns->role = role;
+	ret = cdns->roles[role]->start(cdns);
+	if (!ret)
+		cdns->roles[role]->state = CDNS3_ROLE_STATE_ACTIVE;
+	mutex_unlock(&cdns->mutex);
+	return ret;
+}
+
+void cdns3_role_stop(struct cdns3 *cdns)
+{
+	enum cdns3_roles role = cdns->role;
+
+	if (role >= CDNS3_ROLE_END) {
+		WARN_ON(role > CDNS3_ROLE_END);
+		return;
+	}
+
+	if (cdns->roles[role]->state == CDNS3_ROLE_STATE_INACTIVE)
+		return;
+
+	mutex_lock(&cdns->mutex);
+	cdns->roles[role]->stop(cdns);
+	cdns->roles[role]->state = CDNS3_ROLE_STATE_INACTIVE;
+	mutex_unlock(&cdns->mutex);
+}
+
+/*
+ * cdns->role gets from cdns3_get_initial_role, and this API tells role at the
+ * runtime.
+ * If both roles are supported, the role is selected based on vbus/id.
+ * It could be read from OTG register or external connector.
+ * If only single role is supported, only one role structure
+ * is allocated, cdns->roles[CDNS3_ROLE_HOST] or cdns->roles[CDNS3_ROLE_GADGET].
+ */
+static enum cdns3_roles cdns3_get_initial_role(struct cdns3 *cdns)
+{
+	if (cdns->roles[CDNS3_ROLE_HOST] && cdns->roles[CDNS3_ROLE_GADGET]) {
+		if (cdns3_is_host(cdns))
+			return CDNS3_ROLE_HOST;
+		if (cdns3_is_device(cdns))
+			return CDNS3_ROLE_GADGET;
+	}
+	return cdns->roles[CDNS3_ROLE_HOST]
+		? CDNS3_ROLE_HOST
+		: CDNS3_ROLE_GADGET;
+}
+
+static void cdns3_exit_roles(struct cdns3 *cdns)
+{
+	cdns3_role_stop(cdns);
+	cdns3_drd_exit(cdns);
+}
+
+/**
+ * cdns3_core_init_role - initialize role of operation
+ * @cdns: Pointer to cdns3 structure
+ *
+ * Returns 0 on success otherwise negative errno
+ */
+static int cdns3_core_init_role(struct cdns3 *cdns)
+{
+	struct device *dev = cdns->dev;
+	enum usb_dr_mode best_dr_mode;
+	enum usb_dr_mode dr_mode;
+	int ret = 0;
+
+	dr_mode = usb_get_dr_mode(dev);
+	cdns->role = CDNS3_ROLE_END;
+
+	/*
+	 * If driver can't read mode by means of usb_get_dr_mdoe function then

s/mdoe/mode

quoted

+	 * chooses mode according with Kernel configuration. This setting
+	 * can be restricted later depending on strap pin configuration.
+	 */
+	if (dr_mode == USB_DR_MODE_UNKNOWN) {
+		if (IS_ENABLED(CONFIG_USB_CDNS3_HOST) &&
+		    IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
+			dr_mode = USB_DR_MODE_OTG;
+		else if (IS_ENABLED(CONFIG_USB_CDNS3_HOST))
+			dr_mode = USB_DR_MODE_HOST;
+		else if (IS_ENABLED(CONFIG_USB_CDNS3_GADGET))
+			dr_mode = USB_DR_MODE_PERIPHERAL;
+	}
+
+	best_dr_mode = USB_DR_MODE_OTG;

Might be worth mentioning that cdns->dr_mode is strap configuration
at this point.

I added such information. It could help in understanding code.

quoted

What exactly are we trying to do here?
My guess is that choosen dr_mode can be equal to or subset of strap configuration?

We have three possibility regarding dr_mode:
1. It can be read from strap bits
2. we have kernel configuration 
3. we can read it from dts. 

I assume that driver should select dr_mode considering these three settings. 

quoted

Does this work?

quoted

	if (cdns->dr_mode != USB_DR_MODE_OTG) {
		if (cdns->dr_mode != dr_mode) {
			dev_err(dev, "Incorrect dr_mode configuration: strap %d: requested %d\n",
				cdns->dr_mode, dr_mode);
		}
	}

At this point, dr_mode contains the mode we need to use.

I don't understand. Do you want to replace below block with above condition ?

Yes.

If yes, what with case cdns->dr_mode =  USB_DR_MODE_OTG (strap configuration)
and dr_mode = USB_DR_MODE_HOST (Kernel configuration). 
I think that in this case driver should limit cdns->dr_mode to USB_DR_MODE_HOST 
because gadget driver is disabled.  

You are right. It won't work there.

Of course we can also consider such case as incorrect kernel configuration.

No. It is correct.
I was thinking if we can get rid of best_dr_mode variable entirely, but nevermind.

quoted

quoted

+
+	if (dr_mode == USB_DR_MODE_OTG) {
+		best_dr_mode = cdns->dr_mode;

I think this is wrong. Why do you want to limit to strap configuration when
user wants it to be in OTG?

quoted

quoted

+	} else if (cdns->dr_mode == USB_DR_MODE_OTG) {
+		best_dr_mode = dr_mode;
+	} else if (cdns->dr_mode != dr_mode) {
+		dev_err(dev, "Incorrect DRD configuration\n");
+		return -EINVAL;
+	}
+
+	dr_mode = best_dr_mode;
+
+	if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_HOST) {
+		ret = cdns3_host_init(cdns);
+		if (ret) {
+			dev_err(dev, "Host initialization failed with %d\n",
+				ret);
+			goto err;
+		}
+	}
+
+	if (dr_mode == USB_DR_MODE_OTG || dr_mode == USB_DR_MODE_PERIPHERAL) {
+		ret = cdns3_gadget_init(cdns);
+		if (ret) {
+			dev_err(dev, "Device initialization failed with %d\n",
+				ret);
+			goto err;
+		}
+	}> +
+	cdns->desired_dr_mode = dr_mode;
+	cdns->dr_mode = dr_mode;
+	/*
+	 * dr_mode could be change so DRD must update controller

"desired_dr_mode might have changed so we need to update the controller configuration"?

Sounds better. 

<snip>

-- 
cheers,
-roger

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki