diff mbox

[v2,2/3] usb: phy: add lubbock phy driver

Message ID 1417298525-5587-3-git-send-email-dbaryshkov@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dmitry Baryshkov Nov. 29, 2014, 10:02 p.m. UTC
Extract lubbock-specific code from pxa25x_udc driver. As a bonus, phy
driver determines connector/VBUS status by reading CPLD register. Also
it uses a work to call into udc stack, instead of pinging vbus session
right from irq handler.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
---
 drivers/usb/phy/Kconfig       |  10 ++
 drivers/usb/phy/Makefile      |   1 +
 drivers/usb/phy/phy-lubbock.c | 220 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 231 insertions(+)
 create mode 100644 drivers/usb/phy/phy-lubbock.c

Comments

Jeremiah Mahler Nov. 29, 2014, 10:44 p.m. UTC | #1
Dmitry,

On Sun, Nov 30, 2014 at 01:02:04AM +0300, Dmitry Eremin-Solenikov wrote:
> Extract lubbock-specific code from pxa25x_udc driver. As a bonus, phy
> 
[]
> diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
> index 0cd1f44..98b1682 100644
> --- a/drivers/usb/phy/Kconfig
> +++ b/drivers/usb/phy/Kconfig
> @@ -137,6 +137,16 @@ config USB_ISP1301
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called phy-isp1301.
>  
> +config USB_LUBBOCK
> +	tristate "USB VBUS PHY Driver for DBPXA250 Lubbock platform"
> +	depends on ARCH_LUBBOCK
> +	help
> +	  Say Y here to add support for the USB Gadget VBUS tranceiver driver
                                                        ^^^^^^^^^^
                                                        transceiver
> +	  for DBPXA250 (Lubbock) platform.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called phy-lubbock.
> +
>  config USB_MSM_OTG
>  	tristate "Qualcomm on-chip USB OTG controller support"
>  	depends on (USB || USB_GADGET) && (ARCH_MSM || ARCH_QCOM || COMPILE_TEST)
> diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
> +};
[]
> +module_platform_driver(lubbock_vbus_driver);
> +
> +MODULE_DESCRIPTION("OTG transceiver driver for DBPXA250 Lubbock platform");
> +MODULE_AUTHOR("Dmitry Eremin-Solenikov");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.1.3
> 
> --
[]
Robert Jarzmik Nov. 30, 2014, 9:07 p.m. UTC | #2
Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> writes:

> Extract lubbock-specific code from pxa25x_udc driver. As a bonus, phy
> driver determines connector/VBUS status by reading CPLD register. Also
> it uses a work to call into udc stack, instead of pinging vbus session
> right from irq handler.
This comment is not accurate anymore, right ? The work call, etc ...

Moreover, I have this compile error:
drivers/built-in.o: In function `lubbock_vbus_remove':
/home/rj/mio_linux/kernel/drivers/usb/phy/phy-lubbock.c:200: undefined reference to `usb_remove_phy'
drivers/built-in.o: In function `lubbock_vbus_probe':
/home/rj/mio_linux/kernel/drivers/usb/phy/phy-lubbock.c:186: undefined reference to `usb_add_phy'
Makefile:922: recipe for target 'vmlinux' failed

A select in Kconfig is missing, right ?
And then :
genirq: Threaded irq requested with handler=NULL and !ONESHOT for irq 294
lubbock-vbus lubbock-vbus: can't request irq 294, err: -22
lubbock-vbus: probe of lubbock-vbus failed with error -22

> +static int is_vbus_powered(void)
> +{
> +	return !(LUB_MISC_RD && BIT(9));
That BIT(9) is a bit ugly. Moreover the "&&" is certainly wrong.
A define somewhere would be fine.

> +}
> +
> +static void lubbock_vbus_handle(struct lubbock_vbus_data *lubbock_vbus)
I have not reviewed that one thoroughly ...
> +
> +/* VBUS change IRQ handler */
> +static irqreturn_t lubbock_vbus_irq(int irq, void *data)
> +{
> +	struct platform_device *pdev = data;
> +	struct lubbock_vbus_data *lubbock_vbus = platform_get_drvdata(pdev);
> +	struct usb_otg *otg = lubbock_vbus->phy.otg;
> +
> +	dev_dbg(&pdev->dev, "VBUS %s (gadget: %s)\n",
> +		is_vbus_powered() ? "supplied" : "inactive",
> +		otg->gadget ? otg->gadget->name : "none");
> +
> +	switch (irq) {
> +	case LUBBOCK_USB_IRQ:
> +		disable_irq(LUBBOCK_USB_IRQ);
> +		enable_irq(LUBBOCK_USB_DISC_IRQ);
> +		break;
> +	case LUBBOCK_USB_DISC_IRQ:
> +		disable_irq(LUBBOCK_USB_DISC_IRQ);
> +		enable_irq(LUBBOCK_USB_IRQ);
> +		break;
> +	default:
> +		return IRQ_NONE;
> +	}
> +
> +	/*
> +	 * No need to use workqueue here - we are in a threded handler,
> +	 * so we can sleep.
> +	 */
What if a new interrupt occurs in here, and preempts this thread.

> +	if (otg->gadget)
> +		lubbock_vbus_handle(lubbock_vbus);
I think the enable_irq() call should be here. I can't have an ordering problem
at this point, right ?

> +	err = devm_request_threaded_irq(&pdev->dev, LUBBOCK_USB_DISC_IRQ,
> +			NULL, lubbock_vbus_irq, 0, "vbus disconnect", pdev);
> +	if (err) {
> +		dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
> +			LUBBOCK_USB_DISC_IRQ, err);
> +		return err;
> +	}
> +
> +	err = devm_request_threaded_irq(&pdev->dev, LUBBOCK_USB_IRQ,
> +			NULL, lubbock_vbus_irq, 0, "vbus connect", pdev);
> +	if (err) {
> +		dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
> +			LUBBOCK_USB_IRQ, err);
> +		return err;
> +	}
Here you have both interrupts enabled, this will mean one interrupt at least
will fire. And of course the other one will be enabled a second time, hence
imbalance.

If you want to have an initial status of disconnected gadget, just enable ti
connect interrupt at probing.

Cheers.
Felipe Balbi Jan. 8, 2015, 4:58 p.m. UTC | #3
On Sun, Nov 30, 2014 at 01:02:04AM +0300, Dmitry Eremin-Solenikov wrote:
> Extract lubbock-specific code from pxa25x_udc driver. As a bonus, phy
> driver determines connector/VBUS status by reading CPLD register. Also
> it uses a work to call into udc stack, instead of pinging vbus session
> right from irq handler.
> 
> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> ---
>  drivers/usb/phy/Kconfig       |  10 ++
>  drivers/usb/phy/Makefile      |   1 +

new phy drivers under drivers/phy only, sorry.
Dmitry Baryshkov Jan. 11, 2015, 6:44 p.m. UTC | #4
Hello,

2015-01-08 19:58 GMT+03:00 Felipe Balbi <balbi@ti.com>:
> On Sun, Nov 30, 2014 at 01:02:04AM +0300, Dmitry Eremin-Solenikov wrote:
>> Extract lubbock-specific code from pxa25x_udc driver. As a bonus, phy
>> driver determines connector/VBUS status by reading CPLD register. Also
>> it uses a work to call into udc stack, instead of pinging vbus session
>> right from irq handler.
>>
>> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
>> ---
>>  drivers/usb/phy/Kconfig       |  10 ++
>>  drivers/usb/phy/Makefile      |   1 +
>
> new phy drivers under drivers/phy only, sorry.

Hmm. How do drivers/phy drivers coordinate with usb gadget subsystem?
I see none of them calling usb_gadget_vbus_connect/disconnect().
Felipe Balbi Jan. 12, 2015, 9:51 p.m. UTC | #5
On Sun, Jan 11, 2015 at 10:44:59PM +0400, Dmitry Eremin-Solenikov wrote:
> Hello,
> 
> 2015-01-08 19:58 GMT+03:00 Felipe Balbi <balbi@ti.com>:
> > On Sun, Nov 30, 2014 at 01:02:04AM +0300, Dmitry Eremin-Solenikov wrote:
> >> Extract lubbock-specific code from pxa25x_udc driver. As a bonus, phy
> >> driver determines connector/VBUS status by reading CPLD register. Also
> >> it uses a work to call into udc stack, instead of pinging vbus session
> >> right from irq handler.
> >>
> >> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> >> ---
> >>  drivers/usb/phy/Kconfig       |  10 ++
> >>  drivers/usb/phy/Makefile      |   1 +
> >
> > new phy drivers under drivers/phy only, sorry.
> 
> Hmm. How do drivers/phy drivers coordinate with usb gadget subsystem?
> I see none of them calling usb_gadget_vbus_connect/disconnect().

I'll leave that to Kishon, since he wrote drivers/phy. Kishon, any
hints?
Kishon Vijay Abraham I Jan. 13, 2015, 6:10 a.m. UTC | #6
Hi,

On Tuesday 13 January 2015 03:21 AM, Felipe Balbi wrote:
> On Sun, Jan 11, 2015 at 10:44:59PM +0400, Dmitry Eremin-Solenikov wrote:
>> Hello,
>>
>> 2015-01-08 19:58 GMT+03:00 Felipe Balbi <balbi@ti.com>:
>>> On Sun, Nov 30, 2014 at 01:02:04AM +0300, Dmitry Eremin-Solenikov wrote:
>>>> Extract lubbock-specific code from pxa25x_udc driver. As a bonus, phy
>>>> driver determines connector/VBUS status by reading CPLD register. Also
>>>> it uses a work to call into udc stack, instead of pinging vbus session
>>>> right from irq handler.
>>>>
>>>> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
>>>> ---
>>>>  drivers/usb/phy/Kconfig       |  10 ++
>>>>  drivers/usb/phy/Makefile      |   1 +
>>>
>>> new phy drivers under drivers/phy only, sorry.
>>
>> Hmm. How do drivers/phy drivers coordinate with usb gadget subsystem?
>> I see none of them calling usb_gadget_vbus_connect/disconnect().
> 
> I'll leave that to Kishon, since he wrote drivers/phy. Kishon, any
> hints?

Extcon framework can be used to detect the connector status. So the PHY driver
should register with the extcon framework if it has the capability to determine
the connector status and the gadget driver should register with the extcon
framework if it has to receive the connector status.

I'm not sure if we should be adding these extcon APIs inside the PHY framework
itself as all PHYs might not have the capability to detect the connector status.

Thanks
Kishon
Dmitry Baryshkov Jan. 15, 2015, 1:45 a.m. UTC | #7
Hello,

2015-01-13 9:10 GMT+03:00 Kishon Vijay Abraham I <kishon@ti.com>:
> Hi,
>
> On Tuesday 13 January 2015 03:21 AM, Felipe Balbi wrote:
>> On Sun, Jan 11, 2015 at 10:44:59PM +0400, Dmitry Eremin-Solenikov wrote:
>>> Hello,
>>>
>>> 2015-01-08 19:58 GMT+03:00 Felipe Balbi <balbi@ti.com>:
>>>> On Sun, Nov 30, 2014 at 01:02:04AM +0300, Dmitry Eremin-Solenikov wrote:
>>>>> Extract lubbock-specific code from pxa25x_udc driver. As a bonus, phy
>>>>> driver determines connector/VBUS status by reading CPLD register. Also
>>>>> it uses a work to call into udc stack, instead of pinging vbus session
>>>>> right from irq handler.
>>>>>
>>>>> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
>>>>> ---
>>>>>  drivers/usb/phy/Kconfig       |  10 ++
>>>>>  drivers/usb/phy/Makefile      |   1 +
>>>>
>>>> new phy drivers under drivers/phy only, sorry.
>>>
>>> Hmm. How do drivers/phy drivers coordinate with usb gadget subsystem?
>>> I see none of them calling usb_gadget_vbus_connect/disconnect().
>>
>> I'll leave that to Kishon, since he wrote drivers/phy. Kishon, any
>> hints?
>
> Extcon framework can be used to detect the connector status. So the PHY driver
> should register with the extcon framework if it has the capability to determine
> the connector status and the gadget driver should register with the extcon
> framework if it has to receive the connector status.

If I understand correctly, this means the whole usb gadget/otg subsystem needs
to be redesigned/refactored to support extconn drivers. Is it planned already?
Can we still submit drivers to an old usb-phy subsystem as 'new phy' subsystem
does not provide us necessary integration with usb-gadget subsystem?

>
> I'm not sure if we should be adding these extcon APIs inside the PHY framework
> itself as all PHYs might not have the capability to detect the connector status.

In fact I have several devices for which I had to implement a simple usb-phy
that is able to control D+ pullup, but isn't able to detect VBUS presense
and thus has to assume that the device is always connected.
diff mbox

Patch

diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index 0cd1f44..98b1682 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -137,6 +137,16 @@  config USB_ISP1301
 	  To compile this driver as a module, choose M here: the
 	  module will be called phy-isp1301.
 
+config USB_LUBBOCK
+	tristate "USB VBUS PHY Driver for DBPXA250 Lubbock platform"
+	depends on ARCH_LUBBOCK
+	help
+	  Say Y here to add support for the USB Gadget VBUS tranceiver driver
+	  for DBPXA250 (Lubbock) platform.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called phy-lubbock.
+
 config USB_MSM_OTG
 	tristate "Qualcomm on-chip USB OTG controller support"
 	depends on (USB || USB_GADGET) && (ARCH_MSM || ARCH_QCOM || COMPILE_TEST)
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index 75f2bba..0fe461c 100644
--- a/drivers/usb/phy/Makefile
+++ b/drivers/usb/phy/Makefile
@@ -19,6 +19,7 @@  obj-$(CONFIG_TWL6030_USB)		+= phy-twl6030-usb.o
 obj-$(CONFIG_USB_EHCI_TEGRA)		+= phy-tegra-usb.o
 obj-$(CONFIG_USB_GPIO_VBUS)		+= phy-gpio-vbus-usb.o
 obj-$(CONFIG_USB_ISP1301)		+= phy-isp1301.o
+obj-$(CONFIG_USB_LUBBOCK)		+= phy-lubbock.o
 obj-$(CONFIG_USB_MSM_OTG)		+= phy-msm-usb.o
 obj-$(CONFIG_USB_MV_OTG)		+= phy-mv-usb.o
 obj-$(CONFIG_USB_MXS_PHY)		+= phy-mxs-usb.o
diff --git a/drivers/usb/phy/phy-lubbock.c b/drivers/usb/phy/phy-lubbock.c
new file mode 100644
index 0000000..f73c1a6
--- /dev/null
+++ b/drivers/usb/phy/phy-lubbock.c
@@ -0,0 +1,220 @@ 
+/*
+ * gpio-lubbock.c - VBUS handling code for DBPXA250 platform (lubbock)
+ *
+ * Based on lubbock-vbus.c:
+ * Copyright (c) 2008 Philipp Zabel <philipp.zabel@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/usb.h>
+
+#include <linux/usb/gadget.h>
+#include <linux/usb/otg.h>
+
+#include <mach/hardware.h>
+#include <mach/lubbock.h>
+
+struct lubbock_vbus_data {
+	struct usb_phy		phy;
+	struct device          *dev;
+	int			vbus;
+};
+
+static int is_vbus_powered(void)
+{
+	return !(LUB_MISC_RD && BIT(9));
+}
+
+static void lubbock_vbus_handle(struct lubbock_vbus_data *lubbock_vbus)
+{
+	int status, vbus;
+
+	if (!lubbock_vbus->phy.otg->gadget)
+		return;
+
+	vbus = is_vbus_powered();
+	if ((vbus ^ lubbock_vbus->vbus) == 0)
+		return;
+	lubbock_vbus->vbus = vbus;
+
+	if (vbus) {
+		status = USB_EVENT_VBUS;
+		lubbock_vbus->phy.state = OTG_STATE_B_PERIPHERAL;
+		lubbock_vbus->phy.last_event = status;
+		usb_gadget_vbus_connect(lubbock_vbus->phy.otg->gadget);
+
+		atomic_notifier_call_chain(&lubbock_vbus->phy.notifier,
+				   status, lubbock_vbus->phy.otg->gadget);
+	} else {
+		usb_gadget_vbus_disconnect(lubbock_vbus->phy.otg->gadget);
+		status = USB_EVENT_NONE;
+		lubbock_vbus->phy.state = OTG_STATE_B_IDLE;
+		lubbock_vbus->phy.last_event = status;
+
+		atomic_notifier_call_chain(&lubbock_vbus->phy.notifier,
+				   status, lubbock_vbus->phy.otg->gadget);
+	}
+}
+
+/* VBUS change IRQ handler */
+static irqreturn_t lubbock_vbus_irq(int irq, void *data)
+{
+	struct platform_device *pdev = data;
+	struct lubbock_vbus_data *lubbock_vbus = platform_get_drvdata(pdev);
+	struct usb_otg *otg = lubbock_vbus->phy.otg;
+
+	dev_dbg(&pdev->dev, "VBUS %s (gadget: %s)\n",
+		is_vbus_powered() ? "supplied" : "inactive",
+		otg->gadget ? otg->gadget->name : "none");
+
+	switch (irq) {
+	case LUBBOCK_USB_IRQ:
+		disable_irq(LUBBOCK_USB_IRQ);
+		enable_irq(LUBBOCK_USB_DISC_IRQ);
+		break;
+	case LUBBOCK_USB_DISC_IRQ:
+		disable_irq(LUBBOCK_USB_DISC_IRQ);
+		enable_irq(LUBBOCK_USB_IRQ);
+		break;
+	default:
+		return IRQ_NONE;
+	}
+
+	/*
+	 * No need to use workqueue here - we are in a threded handler,
+	 * so we can sleep.
+	 */
+	if (otg->gadget)
+		lubbock_vbus_handle(lubbock_vbus);
+
+	return IRQ_HANDLED;
+}
+
+/* OTG transceiver interface */
+
+/* bind/unbind the peripheral controller */
+static int lubbock_vbus_set_peripheral(struct usb_otg *otg,
+					struct usb_gadget *gadget)
+{
+	struct lubbock_vbus_data *lubbock_vbus;
+	struct platform_device *pdev;
+
+	lubbock_vbus = container_of(otg->phy, struct lubbock_vbus_data, phy);
+	pdev = to_platform_device(lubbock_vbus->dev);
+
+	if (!gadget) {
+		dev_dbg(&pdev->dev, "unregistering gadget '%s'\n",
+			otg->gadget->name);
+
+		usb_gadget_vbus_disconnect(otg->gadget);
+		otg->phy->state = OTG_STATE_UNDEFINED;
+
+		otg->gadget = NULL;
+		return 0;
+	}
+
+	otg->gadget = gadget;
+	dev_dbg(&pdev->dev, "registered gadget '%s'\n", gadget->name);
+
+	/* initialize connection state */
+	lubbock_vbus->vbus = 0; /* start with disconnected */
+	lubbock_vbus_irq(LUBBOCK_USB_DISC_IRQ, pdev);
+
+	return 0;
+}
+
+/* for non-OTG B devices: set/clear transceiver suspend mode */
+static int lubbock_vbus_set_suspend(struct usb_phy *phy, int suspend)
+{
+	return 0;
+}
+
+/* platform driver interface */
+
+static int lubbock_vbus_probe(struct platform_device *pdev)
+{
+	struct lubbock_vbus_data *lubbock_vbus;
+	int err;
+
+	lubbock_vbus = devm_kzalloc(&pdev->dev,
+			sizeof(struct lubbock_vbus_data),
+			GFP_KERNEL);
+	if (!lubbock_vbus)
+		return -ENOMEM;
+
+	lubbock_vbus->phy.otg = devm_kzalloc(&pdev->dev,
+			sizeof(struct usb_otg),
+			GFP_KERNEL);
+	if (!lubbock_vbus->phy.otg)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, lubbock_vbus);
+	lubbock_vbus->dev = &pdev->dev;
+	lubbock_vbus->phy.label = "lubbock-vbus";
+	lubbock_vbus->phy.dev = lubbock_vbus->dev;
+	lubbock_vbus->phy.set_suspend = lubbock_vbus_set_suspend;
+	lubbock_vbus->phy.state = OTG_STATE_UNDEFINED;
+
+	lubbock_vbus->phy.otg->phy = &lubbock_vbus->phy;
+	lubbock_vbus->phy.otg->set_peripheral = lubbock_vbus_set_peripheral;
+
+	err = devm_request_threaded_irq(&pdev->dev, LUBBOCK_USB_DISC_IRQ,
+			NULL, lubbock_vbus_irq, 0, "vbus disconnect", pdev);
+	if (err) {
+		dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
+			LUBBOCK_USB_DISC_IRQ, err);
+		return err;
+	}
+
+	err = devm_request_threaded_irq(&pdev->dev, LUBBOCK_USB_IRQ,
+			NULL, lubbock_vbus_irq, 0, "vbus connect", pdev);
+	if (err) {
+		dev_err(&pdev->dev, "can't request irq %i, err: %d\n",
+			LUBBOCK_USB_IRQ, err);
+		return err;
+	}
+
+	/* only active when a gadget is registered */
+	err = usb_add_phy(&lubbock_vbus->phy, USB_PHY_TYPE_USB2);
+	if (err) {
+		dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
+			err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int lubbock_vbus_remove(struct platform_device *pdev)
+{
+	struct lubbock_vbus_data *lubbock_vbus = platform_get_drvdata(pdev);
+
+	usb_remove_phy(&lubbock_vbus->phy);
+
+	return 0;
+}
+
+MODULE_ALIAS("platform:lubbock-vbus");
+
+static struct platform_driver lubbock_vbus_driver = {
+	.driver = {
+		.name  = "lubbock-vbus",
+		.owner = THIS_MODULE,
+	},
+	.probe		= lubbock_vbus_probe,
+	.remove		= lubbock_vbus_remove,
+};
+
+module_platform_driver(lubbock_vbus_driver);
+
+MODULE_DESCRIPTION("OTG transceiver driver for DBPXA250 Lubbock platform");
+MODULE_AUTHOR("Dmitry Eremin-Solenikov");
+MODULE_LICENSE("GPL v2");