[RFC PATCH 0/2] Update ehci-platform driver to support devicetree

[RFC PATCH 0/2] Update ehci-platform driver to support devicetree

[Tony Prisk]

This patchset updates the ehci-platform.c driver to allow device tree probing.
I have dropped support for the three function pointers (power_on, power_off
and power_suspend). If someone has knowledge of the power sequence functions
that are being implemented, these functions could be replaced (Sorry, I don't
know anything about implementing it).

port_power_(on_off) properties are not supported in DT as Alan Stern indicated
they are going to be removed.

I have included a binding document, but must admit most of the descriptions
for the properties are guessed. Quite likely some of these descriptions are
incorrect and/or need to be clarified.

Tony Prisk (2):
  USB: Update EHCI-platform driver to devicetree.
  USB: doc: Binding document for ehci-platform driver

 .../devicetree/bindings/usb/ehci-platform.txt      |   22 +++
 drivers/usb/host/ehci-hcd.c                        |    5 -
 drivers/usb/host/ehci-platform.c                   |   46 ++++++
 drivers/usb/host/ehci-vt8500.c                     |  171 --------------------
 4 files changed, 68 insertions(+), 176 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/usb/ehci-platform.txt
 delete mode 100644 drivers/usb/host/ehci-vt8500.c

-- 
1.7.9.5

[PATCH 1/2] USB: Update EHCI-platform driver to devicetree.

[Tony Prisk]

This patch adds devicetree support to the EHCI-platform driver,
and removes the now unneeded ehci-vt8500.c

Existing platform properties are maintained, with the exception
the power_(on/off) and suspend function pointers.

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
---
 drivers/usb/host/ehci-hcd.c      |    5 --
 drivers/usb/host/ehci-platform.c |   46 ++++++++++
 drivers/usb/host/ehci-vt8500.c   |  171 --------------------------------------
 3 files changed, 46 insertions(+), 176 deletions(-)
 delete mode 100644 drivers/usb/host/ehci-vt8500.c

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 6bf6c42..42c8e84 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -1274,11 +1274,6 @@ MODULE_LICENSE ("GPL");
 #define PLATFORM_DRIVER		cns3xxx_ehci_driver
 #endif
 
-#ifdef CONFIG_ARCH_VT8500
-#include "ehci-vt8500.c"
-#define	PLATFORM_DRIVER		vt8500_ehci_driver
-#endif
-
 #ifdef CONFIG_PLAT_SPEAR
 #include "ehci-spear.c"
 #define PLATFORM_DRIVER		spear_ehci_hcd_driver
diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
index 764e010..7f962dc 100644
--- a/drivers/usb/host/ehci-platform.c
+++ b/drivers/usb/host/ehci-platform.c
@@ -19,6 +19,7 @@
  * Licensed under the GNU/GPL. See COPYING for details.
  */
 #include <linux/platform_device.h>
+#include <linux/of.h>
 #include <linux/usb/ehci_pdriver.h>
 
 static int ehci_platform_reset(struct usb_hcd *hcd)
@@ -78,14 +79,48 @@ static const struct hc_driver ehci_platform_hc_driver = {
 	.clear_tt_buffer_complete = ehci_clear_tt_buffer_complete,
 };
 
+static u64 ehci_dma_mask = DMA_BIT_MASK(32);
+
 static int __devinit ehci_platform_probe(struct platform_device *dev)
 {
 	struct usb_hcd *hcd;
 	struct resource *res_mem;
 	struct usb_ehci_pdata *pdata = dev->dev.platform_data;
+	struct device_node *np = dev->dev.of_node;
 	int irq;
 	int err = -ENOMEM;
 
+	/* Are we being initialized from a DT-probed device? */
+	if (np) {
+		/*
+		 * No platform data is being passed, so initalize pdata.
+		 * Limitation: we can't support power_on, power_off or
+		 * power_suspend function pointers from DT.
+		 * TODO: The missing functions could be replaced with
+		 * power sequence handlers.
+		 */
+		pdata = devm_kzalloc(&dev->dev, sizeof(*pdata), GFP_KERNEL);
+		dev->dev.platform_data = pdata;
+
+		/* Read the optional properties from DT node */
+		of_property_read_u32(np, "caps-offset", &pdata->caps_offset);
+		if (of_property_read_bool(np, "has-tt"))
+			pdata->has_tt = 1;
+		if (of_property_read_bool(np, "has-synopsys-hc-bug"))
+			pdata->has_synopsys_hc_bug = 1;
+		if (of_property_read_bool(np, "big-endian-desc"))
+			pdata->big_endian_desc = 1;
+		if (of_property_read_bool(np, "big-endian-mmio"))
+			pdata->big_endian_mmio = 1;
+
+		/* Right now device-tree probed devices don't get dma_mask set.
+		 * Since shared usb code relies on it, set it here for now.
+		 * Once we have dma capability bindings this can go away.
+		 */
+		if (!dev->dev.dma_mask)
+			dev->dev.dma_mask = &ehci_dma_mask;
+	}
+
 	if (!pdata) {
 		WARN_ON(1);
 		return -ENODEV;
@@ -215,6 +250,16 @@ static const struct platform_device_id ehci_platform_table[] = {
 	{ "ehci-platform", 0 },
 	{ }
 };
+
+#ifdef CONFIG_OF
+static const struct of_device_id ehci_platform_ids[] = {
+	{ .compatible = "ehci-platform", },
+	{}
+};
+
+MODULE_DEVICE_TABLE(of, ehci_platform_ids);
+#endif
+
 MODULE_DEVICE_TABLE(platform, ehci_platform_table);
 
 static const struct dev_pm_ops ehci_platform_pm_ops = {
@@ -231,5 +276,6 @@ static struct platform_driver ehci_platform_driver = {
 		.owner	= THIS_MODULE,
 		.name	= "ehci-platform",
 		.pm	= &ehci_platform_pm_ops,
+		.of_match_table = of_match_ptr(ehci_platform_ids),
 	}
 };
diff --git a/drivers/usb/host/ehci-vt8500.c b/drivers/usb/host/ehci-vt8500.c
deleted file mode 100644
index d3c9a3e..0000000
--- a/drivers/usb/host/ehci-vt8500.c
+++ /dev/null
@@ -1,171 +0,0 @@
-/*
- * drivers/usb/host/ehci-vt8500.c
- *
- * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
- *
- * Based on ehci-au1xxx.c
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- */
-
-#include <linux/of.h>
-#include <linux/platform_device.h>
-
-static int ehci_update_device(struct usb_hcd *hcd, struct usb_device *udev)
-{
-	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
-	int rc = 0;
-
-	if (!udev->parent) /* udev is root hub itself, impossible */
-		rc = -1;
-	/* we only support lpm device connected to root hub yet */
-	if (ehci->has_lpm && !udev->parent->parent) {
-		rc = ehci_lpm_set_da(ehci, udev->devnum, udev->portnum);
-		if (!rc)
-			rc = ehci_lpm_check(ehci, udev->portnum);
-	}
-	return rc;
-}
-
-static const struct hc_driver vt8500_ehci_hc_driver = {
-	.description		= hcd_name,
-	.product_desc		= "VT8500 EHCI",
-	.hcd_priv_size		= sizeof(struct ehci_hcd),
-
-	/*
-	 * generic hardware linkage
-	 */
-	.irq			= ehci_irq,
-	.flags			= HCD_MEMORY | HCD_USB2,
-
-	/*
-	 * basic lifecycle operations
-	 */
-	.reset			= ehci_setup,
-	.start			= ehci_run,
-	.stop			= ehci_stop,
-	.shutdown		= ehci_shutdown,
-
-	/*
-	 * managing i/o requests and associated device resources
-	 */
-	.urb_enqueue		= ehci_urb_enqueue,
-	.urb_dequeue		= ehci_urb_dequeue,
-	.endpoint_disable	= ehci_endpoint_disable,
-	.endpoint_reset		= ehci_endpoint_reset,
-
-	/*
-	 * scheduling support
-	 */
-	.get_frame_number	= ehci_get_frame,
-
-	/*
-	 * root hub support
-	 */
-	.hub_status_data	= ehci_hub_status_data,
-	.hub_control		= ehci_hub_control,
-	.bus_suspend		= ehci_bus_suspend,
-	.bus_resume		= ehci_bus_resume,
-	.relinquish_port	= ehci_relinquish_port,
-	.port_handed_over	= ehci_port_handed_over,
-
-	/*
-	 * call back when device connected and addressed
-	 */
-	.update_device =	ehci_update_device,
-
-	.clear_tt_buffer_complete	= ehci_clear_tt_buffer_complete,
-};
-
-static u64 vt8500_ehci_dma_mask = DMA_BIT_MASK(32);
-
-static int vt8500_ehci_drv_probe(struct platform_device *pdev)
-{
-	struct usb_hcd *hcd;
-	struct ehci_hcd *ehci;
-	struct resource *res;
-	int ret;
-
-	if (usb_disabled())
-		return -ENODEV;
-
-	/*
-	 * Right now device-tree probed devices don't get dma_mask set.
-	 * Since shared usb code relies on it, set it here for now.
-	 * Once we have dma capability bindings this can go away.
-	 */
-	if (!pdev->dev.dma_mask)
-		pdev->dev.dma_mask = &vt8500_ehci_dma_mask;
-
-	if (pdev->resource[1].flags != IORESOURCE_IRQ) {
-		pr_debug("resource[1] is not IORESOURCE_IRQ");
-		return -ENOMEM;
-	}
-	hcd = usb_create_hcd(&vt8500_ehci_hc_driver, &pdev->dev, "VT8500");
-	if (!hcd)
-		return -ENOMEM;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	hcd->rsrc_start = res->start;
-	hcd->rsrc_len = resource_size(res);
-
-	hcd->regs = devm_request_and_ioremap(&pdev->dev, res);
-	if (!hcd->regs) {
-		pr_debug("ioremap failed");
-		ret = -ENOMEM;
-		goto err1;
-	}
-
-	ehci = hcd_to_ehci(hcd);
-	ehci->caps = hcd->regs;
-
-	ret = usb_add_hcd(hcd, pdev->resource[1].start,
-			  IRQF_SHARED);
-	if (ret == 0) {
-		platform_set_drvdata(pdev, hcd);
-		return ret;
-	}
-
-err1:
-	usb_put_hcd(hcd);
-	return ret;
-}
-
-static int vt8500_ehci_drv_remove(struct platform_device *pdev)
-{
-	struct usb_hcd *hcd = platform_get_drvdata(pdev);
-
-	usb_remove_hcd(hcd);
-	usb_put_hcd(hcd);
-	platform_set_drvdata(pdev, NULL);
-
-	return 0;
-}
-
-static const struct of_device_id vt8500_ehci_ids[] = {
-	{ .compatible = "via,vt8500-ehci", },
-	{ .compatible = "wm,prizm-ehci", },
-	{}
-};
-
-static struct platform_driver vt8500_ehci_driver = {
-	.probe		= vt8500_ehci_drv_probe,
-	.remove		= vt8500_ehci_drv_remove,
-	.shutdown	= usb_hcd_platform_shutdown,
-	.driver = {
-		.name	= "vt8500-ehci",
-		.owner	= THIS_MODULE,
-		.of_match_table = of_match_ptr(vt8500_ehci_ids),
-	}
-};
-
-MODULE_ALIAS("platform:vt8500-ehci");
-MODULE_DEVICE_TABLE(of, vt8500_ehci_ids);
-- 
1.7.9.5

[PATCH 1/2] USB: Update EHCI-platform driver to devicetree.

[Florian Fainelli]

Hi Tony,

On Saturday 20 October 2012 16:17:32 Tony Prisk wrote:
> This patch adds devicetree support to the EHCI-platform driver,
> and removes the now unneeded ehci-vt8500.c
> 
> Existing platform properties are maintained, with the exception
> the power_(on/off) and suspend function pointers.

Ok, so I have recently sent a bit patchset to remove most OHCI/EHCI drivers
that could be converted to the generic variants, series starts here:
1349701906-16481-1-git-send-email-florian at openwrt.org

in this patchset I added a new property to the EHCI platform data:
need_io_watchdog, which needs to be handled too from DT ideally.

Adding device tree bindings is on my TODO after having a generic way
to pass clocks to the ehci/ohci platform drivers, so you are right on time :)

[snip]

> +	if (np) {
> +		/*
> +		 * No platform data is being passed, so initalize pdata.
> +		 * Limitation: we can't support power_on, power_off or
> +		 * power_suspend function pointers from DT.
> +		 * TODO: The missing functions could be replaced with
> +		 * power sequence handlers.
> +		 */
> +		pdata = devm_kzalloc(&dev->dev, sizeof(*pdata), GFP_KERNEL);

Missing allocation failure handling here. And you should free this in
ehci_platform_remove() accordingly.

> +		dev->dev.platform_data = pdata;
> +
> +		/* Read the optional properties from DT node */
> +		of_property_read_u32(np, "caps-offset", &pdata->caps_offset);
> +		if (of_property_read_bool(np, "has-tt"))
> +			pdata->has_tt = 1;
> +		if (of_property_read_bool(np, "has-synopsys-hc-bug"))
> +			pdata->has_synopsys_hc_bug = 1;
> +		if (of_property_read_bool(np, "big-endian-desc"))
> +			pdata->big_endian_desc = 1;
> +		if (of_property_read_bool(np, "big-endian-mmio"))
> +			pdata->big_endian_mmio = 1;

I would rather we remain compatible with ehci-ppc-of, by handling the 
big-endian property you set big_endian_mmiod and big_endian_desc to 1, and
by setting them individually, you get what you expect.

> +
> +		/* Right now device-tree probed devices don't get dma_mask set.
> +		 * Since shared usb code relies on it, set it here for now.
> +		 * Once we have dma capability bindings this can go away.
> +		 */
> +		if (!dev->dev.dma_mask)
> +			dev->dev.dma_mask = &ehci_dma_mask;
> +	}
> +
>  	if (!pdata) {
>  		WARN_ON(1);
>  		return -ENODEV;
> @@ -215,6 +250,16 @@ static const struct platform_device_id ehci_platform_table[] = {
>  	{ "ehci-platform", 0 },
>  	{ }
>  };
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id ehci_platform_ids[] = {
> +	{ .compatible = "ehci-platform", },
> +	{}

ehci-platform is very linux-specific, so this should either be:
"linux,ehci-platform", or "usb-ehci", pretty much like the ppc-of ehci driver.
-- 
Florian

[PATCH 1/2] USB: Update EHCI-platform driver to devicetree.

[Alan Stern]

On Sat, 20 Oct 2012, Florian Fainelli wrote:

> Hi Tony,
> 
> On Saturday 20 October 2012 16:17:32 Tony Prisk wrote:
> > This patch adds devicetree support to the EHCI-platform driver,
> > and removes the now unneeded ehci-vt8500.c
> > 
> > Existing platform properties are maintained, with the exception
> > the power_(on/off) and suspend function pointers.
> 
> Ok, so I have recently sent a bit patchset to remove most OHCI/EHCI drivers
> that could be converted to the generic variants, series starts here:
> 1349701906-16481-1-git-send-email-florian at openwrt.org
> 
> in this patchset I added a new property to the EHCI platform data:
> need_io_watchdog, which needs to be handled too from DT ideally.

Actually the new property is "no_io_watchdog".  See

	http://marc.info/?l=linux-usb&m=134970247511140&w=2

> Adding device tree bindings is on my TODO after having a generic way
> to pass clocks to the ehci/ohci platform drivers, so you are right on time :)

At some point we'll need a way to handle the power_{on,off,suspend} 
callbacks.  I don't know how that should be done.

Alan Stern

[PATCH 1/2] USB: Update EHCI-platform driver to devicetree.

[Tony Prisk]

On Sat, 2012-10-20 at 10:31 -0400, Alan Stern wrote:
> On Sat, 20 Oct 2012, Florian Fainelli wrote:
> 
> > Hi Tony,
> > 
> > On Saturday 20 October 2012 16:17:32 Tony Prisk wrote:
> > > This patch adds devicetree support to the EHCI-platform driver,
> > > and removes the now unneeded ehci-vt8500.c
> > > 
> > > Existing platform properties are maintained, with the exception
> > > the power_(on/off) and suspend function pointers.
> > 
> > Ok, so I have recently sent a bit patchset to remove most OHCI/EHCI drivers
> > that could be converted to the generic variants, series starts here:
> > 1349701906-16481-1-git-send-email-florian at openwrt.org
> > 
> > in this patchset I added a new property to the EHCI platform data:
> > need_io_watchdog, which needs to be handled too from DT ideally.
> 
> Actually the new property is "no_io_watchdog".  See
> 
> 	http://marc.info/?l=linux-usb&m=134970247511140&w=2
> 
> > Adding device tree bindings is on my TODO after having a generic way
> > to pass clocks to the ehci/ohci platform drivers, so you are right on time :)
> 
> At some point we'll need a way to handle the power_{on,off,suspend} 
> callbacks.  I don't know how that should be done.
> 
> Alan Stern

I actually included a comment in the patch regarding the missing
functions:

> +                * No platform data is being passed, so initalize
> pdata.
> +                * Limitation: we can't support power_on, power_off or
> +                * power_suspend function pointers from DT.
> +                * TODO: The missing functions could be replaced with
> +                * power sequence handlers.
> +                */

I don't know anything about the power sequence code, but have seen some
patches for pwm backlight using it. I don't know if it would allow
everything that's needed, but it seems to have support for voltage
regulators and gpios (among other things).

Regards
Tony P

[PATCH 1/2] USB: Update EHCI-platform driver to devicetree.

[Tony Prisk]

On Sat, 2012-10-20 at 15:01 +0200, Florian Fainelli wrote:
> Hi Tony,
> 
> On Saturday 20 October 2012 16:17:32 Tony Prisk wrote:
> > This patch adds devicetree support to the EHCI-platform driver,
> > and removes the now unneeded ehci-vt8500.c
> > 
> > Existing platform properties are maintained, with the exception
> > the power_(on/off) and suspend function pointers.
> 
> Ok, so I have recently sent a bit patchset to remove most OHCI/EHCI drivers
> that could be converted to the generic variants, series starts here:
> 1349701906-16481-1-git-send-email-florian at openwrt.org
> 
> in this patchset I added a new property to the EHCI platform data:
> need_io_watchdog, which needs to be handled too from DT ideally.
> 
> Adding device tree bindings is on my TODO after having a generic way
> to pass clocks to the ehci/ohci platform drivers, so you are right on time :)
> 
> [snip]
> 
> > +	if (np) {
> > +		/*
> > +		 * No platform data is being passed, so initalize pdata.
> > +		 * Limitation: we can't support power_on, power_off or
> > +		 * power_suspend function pointers from DT.
> > +		 * TODO: The missing functions could be replaced with
> > +		 * power sequence handlers.
> > +		 */
> > +		pdata = devm_kzalloc(&dev->dev, sizeof(*pdata), GFP_KERNEL);
> 
> Missing allocation failure handling here. And you should free this in
> ehci_platform_remove() accordingly.

Oops - good catch. Will fix.
> 
> > +		dev->dev.platform_data = pdata;
> > +
> > +		/* Read the optional properties from DT node */
> > +		of_property_read_u32(np, "caps-offset", &pdata->caps_offset);
> > +		if (of_property_read_bool(np, "has-tt"))
> > +			pdata->has_tt = 1;
> > +		if (of_property_read_bool(np, "has-synopsys-hc-bug"))
> > +			pdata->has_synopsys_hc_bug = 1;
> > +		if (of_property_read_bool(np, "big-endian-desc"))
> > +			pdata->big_endian_desc = 1;
> > +		if (of_property_read_bool(np, "big-endian-mmio"))
> > +			pdata->big_endian_mmio = 1;
> 
> I would rather we remain compatible with ehci-ppc-of, by handling the 
> big-endian property you set big_endian_mmiod and big_endian_desc to 1, and
> by setting them individually, you get what you expect.

I noticed in the usb-ehci.txt binding document, it lists
big-endian-regs, big-endian-desc and big-endian so perhaps we should
rename all these to match.
> 
> > +
> > +		/* Right now device-tree probed devices don't get dma_mask set.
> > +		 * Since shared usb code relies on it, set it here for now.
> > +		 * Once we have dma capability bindings this can go away.
> > +		 */
> > +		if (!dev->dev.dma_mask)
> > +			dev->dev.dma_mask = &ehci_dma_mask;
> > +	}
> > +
> >  	if (!pdata) {
> >  		WARN_ON(1);
> >  		return -ENODEV;
> > @@ -215,6 +250,16 @@ static const struct platform_device_id ehci_platform_table[] = {
> >  	{ "ehci-platform", 0 },
> >  	{ }
> >  };
> > +
> > +#ifdef CONFIG_OF
> > +static const struct of_device_id ehci_platform_ids[] = {
> > +	{ .compatible = "ehci-platform", },
> > +	{}
> 
> ehci-platform is very linux-specific, so this should either be:
> "linux,ehci-platform", or "usb-ehci", pretty much like the ppc-of ehci driver.

Anyone has any preferences? This change should also be applied to
platform-uhci to keep everything uniform (and ohci-platform eventually
as well).

[PATCH 2/2] USB: doc: Binding document for ehci-platform driver

[Tony Prisk]

Add a binding document for ehci-platform driver.

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
---
 .../devicetree/bindings/usb/ehci-platform.txt      |   22 ++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/usb/ehci-platform.txt

diff --git a/Documentation/devicetree/bindings/usb/ehci-platform.txt b/Documentation/devicetree/bindings/usb/ehci-platform.txt
new file mode 100644
index 0000000..faeffe4
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/ehci-platform.txt
@@ -0,0 +1,22 @@
+Generic Platform EHCI Controller
+-----------------------------------------------------
+
+Required properties:
+- compatible : "ehci-platform"
+- reg : Should contain 1 register ranges(address and length)
+- interrupts : EHCI controller interrupt
+
+Optional properties:
+- caps-offset : offset to the capabilities register (default = 0)
+- has-tt : controller has transaction translator(s).
+- big-endian-desc : descriptors are in big-endian format
+- big-endian-mmio : mmio is in big-endian format
+- has-synopsys-hc-bug : controller has the synopsys hc bug
+
+Example:
+	ehci at d8007c00 {
+		compatible = "ehci-platform";
+		reg = <0xd8007c00 0x200>;
+		interrupts = <43>;
+		has-tt;
+	};
-- 
1.7.9.5

[RFC PATCH 0/2] Update ehci-platform driver to support devicetree

[Alan Stern]

On Sat, 20 Oct 2012, Tony Prisk wrote:

> This patchset updates the ehci-platform.c driver to allow device tree probing.
> I have dropped support for the three function pointers (power_on, power_off
> and power_suspend). If someone has knowledge of the power sequence functions
> that are being implemented, these functions could be replaced (Sorry, I don't
> know anything about implementing it).
> 
> port_power_(on_off) properties are not supported in DT as Alan Stern indicated
> they are going to be removed.
> 
> I have included a binding document, but must admit most of the descriptions
> for the properties are guessed. Quite likely some of these descriptions are
> incorrect and/or need to be clarified.

They look okay to me.  Over time we may need to add a few more entries, 
as more drivers are converted over to ehci-platform.

> Tony Prisk (2):
>   USB: Update EHCI-platform driver to devicetree.
>   USB: doc: Binding document for ehci-platform driver

This is very good; thanks for doing the work.

Alan Stern