[RFC 0/5] usb: chipidea: Add support for Tegra20 through Tegra124

[RFC 0/5] usb: chipidea: Add support for Tegra20 through Tegra124

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

All Tegra SoC generations from Tegra20 through Tegra124 have a ChipIdea
USB device controller. This set of patches adds very rudimentary support
for it to the existing ChipIdea driver and enables them on the set of
boards that I could easily test on.

I'm sending this out as RFC because I'm not sure yet how to merge this.
While the driver seems to work fine (tested by exporting a USB driver or
eMMC via the mass storage function) I don't yet understand how to make
the driver switch between host and device modes dynamically. It might be
useful to get this merged before, but I'd like to have some feedback on
this, because doing so would mean that we need to use device mode on the
devices where it's enabled and can't use the USBD port in host mode.

Thierry

Thierry Reding (5):
  usb: chipidea: Add support for Tegra20/30/114/124
  ARM: tegra: Enable UDC on TrimSlice
  ARM: tegra: Enable UDC on Beaver
  ARM: tegra: Enable UDC on Dalmore
  ARM: tegra: Enable UDC on Jetson TK1

 arch/arm/boot/dts/tegra114-dalmore.dts    |  11 +++
 arch/arm/boot/dts/tegra124-jetson-tk1.dts |  13 +++-
 arch/arm/boot/dts/tegra20-trimslice.dts   |   3 +
 arch/arm/boot/dts/tegra30-beaver.dts      |  11 +++
 drivers/usb/chipidea/Makefile             |   1 +
 drivers/usb/chipidea/ci_hdrc_tegra.c      | 109 ++++++++++++++++++++++++++++++
 6 files changed, 147 insertions(+), 1 deletion(-)
 create mode 100644 drivers/usb/chipidea/ci_hdrc_tegra.c

-- 
2.8.3

[RFC 1/5] usb: chipidea: Add support for Tegra20/30/114/124

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

All of these Tegra SoC generations have a ChipIdea UDC IP block that can
be used for device mode communication with a host. Implement rudimentary
support that doesn't allow switching between host and device modes.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/usb/chipidea/Makefile        |   1 +
 drivers/usb/chipidea/ci_hdrc_tegra.c | 109 +++++++++++++++++++++++++++++++++++
 2 files changed, 110 insertions(+)
 create mode 100644 drivers/usb/chipidea/ci_hdrc_tegra.c

diff --git a/drivers/usb/chipidea/Makefile b/drivers/usb/chipidea/Makefile
index 518e445476c3..3532df6561d9 100644
--- a/drivers/usb/chipidea/Makefile
+++ b/drivers/usb/chipidea/Makefile
@@ -10,6 +10,7 @@ ci_hdrc-$(CONFIG_USB_OTG_FSM)		+= otg_fsm.o
 obj-$(CONFIG_USB_CHIPIDEA)	+= ci_hdrc_usb2.o
 obj-$(CONFIG_USB_CHIPIDEA)	+= ci_hdrc_msm.o
 obj-$(CONFIG_USB_CHIPIDEA)	+= ci_hdrc_zevio.o
+obj-$(CONFIG_USB_CHIPIDEA)	+= ci_hdrc_tegra.o
 
 obj-$(CONFIG_USB_CHIPIDEA_PCI)	+= ci_hdrc_pci.o
 
diff --git a/drivers/usb/chipidea/ci_hdrc_tegra.c b/drivers/usb/chipidea/ci_hdrc_tegra.c
new file mode 100644
index 000000000000..d3cd68441856
--- /dev/null
+++ b/drivers/usb/chipidea/ci_hdrc_tegra.c
@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2016, NVIDIA Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+#include <linux/usb/chipidea.h>
+
+#include "ci.h"
+
+struct tegra_udc {
+	struct ci_hdrc_platform_data data;
+	struct platform_device *dev;
+
+	struct usb_phy *phy;
+	struct clk *clk;
+};
+
+static const struct of_device_id tegra_udc_of_match[] = {
+	{ .compatible = "nvidia,tegra20-udc" },
+	{ .compatible = "nvidia,tegra30-udc" },
+	{ .compatible = "nvidia,tegra114-udc" },
+	{ .compatible = "nvidia,tegra124-udc" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, tegra_udc_of_match);
+
+static int tegra_udc_probe(struct platform_device *pdev)
+{
+	struct tegra_udc *udc;
+	int err;
+
+	udc = devm_kzalloc(&pdev->dev, sizeof(*udc), GFP_KERNEL);
+	if (!udc)
+		return -ENOMEM;
+
+	udc->phy = devm_usb_get_phy_by_phandle(&pdev->dev, "nvidia,phy", 0);
+	if (IS_ERR(udc->phy)) {
+		err = PTR_ERR(udc->phy);
+		dev_err(&pdev->dev, "failed to get PHY: %d\n", err);
+		return err;
+	}
+
+	udc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(udc->clk)) {
+		err = PTR_ERR(udc->clk);
+		dev_err(&pdev->dev, "failed to get clock: %d\n", err);
+		return err;
+	}
+
+	err = clk_prepare_enable(udc->clk);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to enable clock: %d\n", err);
+		return err;
+	}
+
+	/* setup and register ChipIdea HDRC device */
+	udc->data.name = "tegra-udc";
+	udc->data.capoffset = DEF_CAPOFFSET;
+	udc->data.flags = 0;
+	udc->data.usb_phy = udc->phy;
+
+	udc->dev = ci_hdrc_add_device(&pdev->dev, pdev->resource,
+				      pdev->num_resources, &udc->data);
+	if (IS_ERR(udc->dev)) {
+		err = PTR_ERR(udc->dev);
+		dev_err(&pdev->dev, "failed to add HDRC device: %d\n", err);
+		goto disable_clock;
+	}
+
+	platform_set_drvdata(pdev, udc);
+
+	return 0;
+
+disable_clock:
+	clk_disable_unprepare(udc->clk);
+	return err;
+}
+
+static int tegra_udc_remove(struct platform_device *pdev)
+{
+	struct tegra_udc *udc = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(udc->clk);
+
+	return 0;
+}
+
+static struct platform_driver tegra_udc_driver = {
+	.driver = {
+		.name = "tegra-udc",
+		.of_match_table = tegra_udc_of_match,
+	},
+	.probe = tegra_udc_probe,
+	.remove = tegra_udc_remove,
+};
+module_platform_driver(tegra_udc_driver);
+
+MODULE_DESCRIPTION("NVIDIA Tegra USB device mode driver");
+MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
+MODULE_ALIAS("platform:tegra-udc");
+MODULE_LICENSE("GPL v2");
-- 
2.8.3

Re: [RFC 1/5] usb: chipidea: Add support for Tegra20/30/114/124

[Stephen Warren]

On 05/26/2016 09:40 AM, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
>
> All of these Tegra SoC generations have a ChipIdea UDC IP block that can
> be used for device mode communication with a host. Implement rudimentary
> support that doesn't allow switching between host and device modes.

Are you sure this is correct for Tegra20? I ask because for the /host/ 
mode driver, there's a "has_hostpc" flag which is set to false for 
Tegra20 and true for all other SoCs. In the U-Boot device mode driver 
(if not in the kernel driver; I didn't check), there's a concept of "has 
hostpc" too. I might expect that flag to be set the same way for both 
drivers. That said, I /think/ the host and device HW are unrelated, so 
it's possible has_hostpc might be set differently for them. 
Unfortunately, we haven't enabled the device mode driver for any Tegra20 
system in U-Boot so I can't tell whether we should enable has_hostpc for 
Tegra20's device mode driver.

Still, if this code works then I guess it's likely correct...

Re: [RFC 1/5] usb: chipidea: Add support for Tegra20/30/114/124

[Stephen Warren]

On 05/26/2016 03:17 PM, Stephen Warren wrote:
> On 05/26/2016 09:40 AM, Thierry Reding wrote:
>> From: Thierry Reding <treding@nvidia.com>
>>
>> All of these Tegra SoC generations have a ChipIdea UDC IP block that can
>> be used for device mode communication with a host. Implement rudimentary
>> support that doesn't allow switching between host and device modes.
>
> Are you sure this is correct for Tegra20? I ask because for the /host/
> mode driver, there's a "has_hostpc" flag which is set to false for
> Tegra20 and true for all other SoCs. In the U-Boot device mode driver
> (if not in the kernel driver; I didn't check), there's a concept of "has
> hostpc" too. I might expect that flag to be set the same way for both
> drivers. That said, I /think/ the host and device HW are unrelated, so
> it's possible has_hostpc might be set differently for them.
> Unfortunately, we haven't enabled the device mode driver for any Tegra20
> system in U-Boot so I can't tell whether we should enable has_hostpc for
> Tegra20's device mode driver.
>
> Still, if this code works then I guess it's likely correct...

On the other hand, it looks like the kernel device mode driver might 
auto-detect this; in core.c:hw_device_init(), I see:

         reg = hw_read(ci, CAP_HCCPARAMS, HCCPARAMS_LEN) >>
                 __ffs(HCCPARAMS_LEN);
         ci->hw_bank.lpm  = reg;

... and in host.c:host_start(), I see:

	ehci->has_hostpc = ci->hw_bank.lpm;

[RFC 2/5] ARM: tegra: Enable UDC on TrimSlice

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Override the compatible string of the first USB controller to enable
device mode.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 arch/arm/boot/dts/tegra20-trimslice.dts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm/boot/dts/tegra20-trimslice.dts b/arch/arm/boot/dts/tegra20-trimslice.dts
index 4a035f74043a..5496f3dc089c 100644
--- a/arch/arm/boot/dts/tegra20-trimslice.dts
+++ b/arch/arm/boot/dts/tegra20-trimslice.dts
@@ -336,11 +336,14 @@
 	};
 
 	usb@c5000000 {
+		compatible = "nvidia,tegra20-udc";
 		status = "okay";
+		dr_mode = "otg";
 	};
 
 	usb-phy@c5000000 {
 		status = "okay";
+		dr_mode = "otg";
 		vbus-supply = <&vbus_reg>;
 	};
 
-- 
2.8.3

[RFC 3/5] ARM: tegra: Enable UDC on Beaver

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Override the compatible string of the first USB controller to enable
device mode.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 arch/arm/boot/dts/tegra30-beaver.dts | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/arm/boot/dts/tegra30-beaver.dts b/arch/arm/boot/dts/tegra30-beaver.dts
index 4ea3ecc10934..5f32bcd96fbc 100644
--- a/arch/arm/boot/dts/tegra30-beaver.dts
+++ b/arch/arm/boot/dts/tegra30-beaver.dts
@@ -1935,6 +1935,17 @@
 		non-removable;
 	};
 
+	usb@7d000000 {
+		compatible = "nvidia,tegra30-udc";
+		status = "okay";
+		dr_mode = "otg";
+	};
+
+	usb-phy@7d000000 {
+		status = "okay";
+		dr_mode = "otg";
+	};
+
 	usb@7d004000 {
 		status = "okay";
 	};
-- 
2.8.3

[RFC 4/5] ARM: tegra: Enable UDC on Dalmore

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Override the compatible string of the first USB controller to enable
device mode.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 arch/arm/boot/dts/tegra114-dalmore.dts | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/arm/boot/dts/tegra114-dalmore.dts b/arch/arm/boot/dts/tegra114-dalmore.dts
index c970bf65c74c..53d664f718ff 100644
--- a/arch/arm/boot/dts/tegra114-dalmore.dts
+++ b/arch/arm/boot/dts/tegra114-dalmore.dts
@@ -1122,6 +1122,17 @@
 		non-removable;
 	};
 
+	usb@7d000000 {
+		compatible = "nvidia,tegra114-udc";
+		status = "okay";
+		dr_mode = "otg";
+	};
+
+	usb-phy@7d000000 {
+		status = "okay";
+		dr_mode = "otg";
+	};
+
 	usb@7d008000 {
 		status = "okay";
 	};
-- 
2.8.3

Re: [RFC 4/5] ARM: tegra: Enable UDC on Dalmore

[Peter Chen]

On Thu, May 26, 2016 at 05:40:04PM +0200, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> Override the compatible string of the first USB controller to enable
> device mode.
> 
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  arch/arm/boot/dts/tegra114-dalmore.dts | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/tegra114-dalmore.dts b/arch/arm/boot/dts/tegra114-dalmore.dts
> index c970bf65c74c..53d664f718ff 100644
> --- a/arch/arm/boot/dts/tegra114-dalmore.dts
> +++ b/arch/arm/boot/dts/tegra114-dalmore.dts
> @@ -1122,6 +1122,17 @@
>  		non-removable;
>  	};
>  
> +	usb@7d000000 {
> +		compatible = "nvidia,tegra114-udc";
> +		status = "okay";
> +		dr_mode = "otg";
> +	};
> +
> +	usb-phy@7d000000 {
> +		status = "okay";
> +		dr_mode = "otg";
> +	};
> +

It is a USB PHY node, you don't need to set dr_mode for it.

-- 

Best Regards,
Peter Chen

[RFC 5/5] ARM: tegra: Enable UDC on Jetson TK1

[Thierry Reding]

From: Thierry Reding <treding@nvidia.com>

Override the compatible string of the first USB controller to enable
device mode.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 arch/arm/boot/dts/tegra124-jetson-tk1.dts | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/tegra124-jetson-tk1.dts b/arch/arm/boot/dts/tegra124-jetson-tk1.dts
index 941f36263c8f..30e92cc85b86 100644
--- a/arch/arm/boot/dts/tegra124-jetson-tk1.dts
+++ b/arch/arm/boot/dts/tegra124-jetson-tk1.dts
@@ -1726,7 +1726,7 @@
 
 				lanes {
 					usb2-0 {
-						nvidia,function = "xusb";
+						nvidia,function = "snps";
 						status = "okay";
 					};
 
@@ -1833,6 +1833,17 @@
 		};
 	};
 
+	usb@0,7d000000 {
+		compatible = "nvidia,tegra124-udc";
+		status = "okay";
+		dr_mode = "otg";
+	};
+
+	usb-phy@0,7d000000 {
+		status = "okay";
+		dr_mode = "otg";
+	};
+
 	/* mini-PCIe USB */
 	usb@0,7d004000 {
 		status = "okay";
-- 
2.8.3

Re: [RFC 0/5] usb: chipidea: Add support for Tegra20 through Tegra124

[Peter Chen]

On Thu, May 26, 2016 at 05:40:00PM +0200, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> All Tegra SoC generations from Tegra20 through Tegra124 have a ChipIdea
> USB device controller. This set of patches adds very rudimentary support
> for it to the existing ChipIdea driver and enables them on the set of
> boards that I could easily test on.
> 
> I'm sending this out as RFC because I'm not sure yet how to merge this.
> While the driver seems to work fine (tested by exporting a USB driver or
> eMMC via the mass storage function) I don't yet understand how to make
> the driver switch between host and device modes dynamically. It might be
> useful to get this merged before, but I'd like to have some feedback on
> this, because doing so would mean that we need to use device mode on the
> devices where it's enabled and can't use the USBD port in host mode.
> 

Chipidea driver supports many ways to switch between host and device
mode. It can support switching with/without disconnecting cable.

Most of cases need to disconnect cable (Micro-AB) to switch between
host and device mode, I just take this as an example:

Using ID pin which is at Micro-B receptacle on the board to determine host (ID = 0)
or device (ID = 1 )mode.

- ID pin connects to CPU, and ID interrupt and value can be get through
register OTGSC.
- ID pin does not connect to CPU, and there is a dedicated GPIO for ID.

-- 

Best Regards,
Peter Chen