diff mbox

[v3,1/2] usb: dwc3: Add Keystone specific glue layer

Message ID 1386627424-373-2-git-send-email-w-kwok2@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

WingMan Kwok Dec. 9, 2013, 10:17 p.m. UTC
Add Keystone platform specific glue layer to support
USB3 Host mode.

Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: WingMan Kwok <w-kwok2@ti.com>
---
 drivers/usb/dwc3/Kconfig         |    7 ++
 drivers/usb/dwc3/Makefile        |    1 +
 drivers/usb/dwc3/dwc3-keystone.c |  205 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 213 insertions(+)
 create mode 100644 drivers/usb/dwc3/dwc3-keystone.c

Comments

Felipe Balbi Dec. 10, 2013, 2:51 a.m. UTC | #1
Hi,

On Mon, Dec 09, 2013 at 05:17:03PM -0500, WingMan Kwok wrote:
> +static void kdwc3_enable_irqs(struct dwc3_keystone *kdwc)
> +{
> +	u32 val;
> +
> +	val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
> +	val = USBSS_IRQ_COREIRQ_EN;

this misses the | in |=. I can fix it up while applying, this time only.

> +static int kdwc3_probe(struct platform_device *pdev)
> +{
> +	struct device		*dev = &pdev->dev;
> +	struct device_node	*node = pdev->dev.of_node;
> +	struct dwc3_keystone	*kdwc;
> +	struct resource		*res;
> +	int			error, irq;
> +
> +	kdwc = devm_kzalloc(dev, sizeof(*kdwc), GFP_KERNEL);
> +	if (!kdwc)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, kdwc);
> +
> +	kdwc->dev = dev;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		dev_err(dev, "missing usbss resource\n");
> +		return -EINVAL;
> +	}
> +
> +	kdwc->usbss = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(kdwc->usbss))
> +		return PTR_ERR(kdwc->usbss);
> +
> +	kdwc3_dma_mask = dma_get_mask(dev);
> +	dev->dma_mask = &kdwc3_dma_mask;
> +
> +	kdwc->clk = devm_clk_get(kdwc->dev, "usb");
> +	if (IS_ERR_OR_NULL(kdwc->clk)) {

clk_get() will never return NULL. This time, I'll fix it while applying.

> +static int kdwc3_remove(struct platform_device *pdev)
> +{
> +	struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
> +
> +	kdwc3_disable_irqs(kdwc);
> +	clk_disable_unprepare(kdwc->clk);

I hope the clock isn't shared between core and wrapper, otherwise you
could run into some troubles here. Can you confirm ?
Santosh Shilimkar Dec. 10, 2013, 3:11 p.m. UTC | #2
On Monday 09 December 2013 09:51 PM, Balbi, Felipe wrote:
> Hi,
> 
> On Mon, Dec 09, 2013 at 05:17:03PM -0500, WingMan Kwok wrote:
>> +static void kdwc3_enable_irqs(struct dwc3_keystone *kdwc)
>> +{
>> +	u32 val;
>> +
>> +	val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
>> +	val = USBSS_IRQ_COREIRQ_EN;
> 
> this misses the | in |=. I can fix it up while applying, this time only.
> 
>> +static int kdwc3_probe(struct platform_device *pdev)
>> +{
>> +	struct device		*dev = &pdev->dev;
>> +	struct device_node	*node = pdev->dev.of_node;
>> +	struct dwc3_keystone	*kdwc;
>> +	struct resource		*res;
>> +	int			error, irq;
>> +
>> +	kdwc = devm_kzalloc(dev, sizeof(*kdwc), GFP_KERNEL);
>> +	if (!kdwc)
>> +		return -ENOMEM;
>> +
>> +	platform_set_drvdata(pdev, kdwc);
>> +
>> +	kdwc->dev = dev;
>> +
>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	if (!res) {
>> +		dev_err(dev, "missing usbss resource\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	kdwc->usbss = devm_ioremap_resource(dev, res);
>> +	if (IS_ERR(kdwc->usbss))
>> +		return PTR_ERR(kdwc->usbss);
>> +
>> +	kdwc3_dma_mask = dma_get_mask(dev);
>> +	dev->dma_mask = &kdwc3_dma_mask;
>> +
>> +	kdwc->clk = devm_clk_get(kdwc->dev, "usb");
>> +	if (IS_ERR_OR_NULL(kdwc->clk)) {
> 
> clk_get() will never return NULL. This time, I'll fix it while applying.
> 
>> +static int kdwc3_remove(struct platform_device *pdev)
>> +{
>> +	struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
>> +
>> +	kdwc3_disable_irqs(kdwc);
>> +	clk_disable_unprepare(kdwc->clk);
> 
> I hope the clock isn't shared between core and wrapper, otherwise you
> could run into some troubles here. Can you confirm ?
> 
Yes. the clock isn't shared. Thanks for taking care of other parts.
Felipe Balbi Dec. 12, 2013, 5:48 p.m. UTC | #3
Hi,

On Tue, Dec 10, 2013 at 10:11:36AM -0500, Santosh Shilimkar wrote:
> >> +static int kdwc3_remove(struct platform_device *pdev)
> >> +{
> >> +	struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
> >> +
> >> +	kdwc3_disable_irqs(kdwc);
> >> +	clk_disable_unprepare(kdwc->clk);
> > 
> > I hope the clock isn't shared between core and wrapper, otherwise you
> > could run into some troubles here. Can you confirm ?
> > 
> Yes. the clock isn't shared. Thanks for taking care of other parts.

so clock for core is always running too ?
Santosh Shilimkar Dec. 12, 2013, 7:36 p.m. UTC | #4
On Thursday 12 December 2013 12:48 PM, Felipe Balbi wrote:
> Hi,
> 
> On Tue, Dec 10, 2013 at 10:11:36AM -0500, Santosh Shilimkar wrote:
>>>> +static int kdwc3_remove(struct platform_device *pdev)
>>>> +{
>>>> +	struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
>>>> +
>>>> +	kdwc3_disable_irqs(kdwc);
>>>> +	clk_disable_unprepare(kdwc->clk);
>>>
>>> I hope the clock isn't shared between core and wrapper, otherwise you
>>> could run into some troubles here. Can you confirm ?
>>>
>> Yes. the clock isn't shared. Thanks for taking care of other parts.
> 
> so clock for core is always running too ?
> 
I take that back. The clock is actually common so we should disable
it after removing the  kdwc3_remove_core() as you suggested.

You won't see issue since the  kdwc3_remove_core() not doing
any register access but moving the clock disable after
the core remove is right thing to do.

Regards,
Santosh
Felipe Balbi Dec. 12, 2013, 7:41 p.m. UTC | #5
On Thu, Dec 12, 2013 at 02:36:01PM -0500, Santosh Shilimkar wrote:
> On Thursday 12 December 2013 12:48 PM, Felipe Balbi wrote:
> > Hi,
> > 
> > On Tue, Dec 10, 2013 at 10:11:36AM -0500, Santosh Shilimkar wrote:
> >>>> +static int kdwc3_remove(struct platform_device *pdev)
> >>>> +{
> >>>> +	struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
> >>>> +
> >>>> +	kdwc3_disable_irqs(kdwc);
> >>>> +	clk_disable_unprepare(kdwc->clk);
> >>>
> >>> I hope the clock isn't shared between core and wrapper, otherwise you
> >>> could run into some troubles here. Can you confirm ?
> >>>
> >> Yes. the clock isn't shared. Thanks for taking care of other parts.
> > 
> > so clock for core is always running too ?
> > 
> I take that back. The clock is actually common so we should disable
> it after removing the  kdwc3_remove_core() as you suggested.
> 
> You won't see issue since the  kdwc3_remove_core() not doing
> any register access but moving the clock disable after
> the core remove is right thing to do.

the problem is not kdwc3_remove_core() accessing registers, but
dwc3_remove() _does_ access registers during remove. If you just
mopdrobe -r dwc3-keystone without removing dwc3.ko first, then
kdwc3_remove_core() will cause dwc3.ko to be removed (because of
platform_driver_unregister()) and, since clocks have already been
disabled, then we'd die :-)

cheers
Santosh Shilimkar Dec. 12, 2013, 7:52 p.m. UTC | #6
On Thursday 12 December 2013 02:41 PM, Felipe Balbi wrote:
> On Thu, Dec 12, 2013 at 02:36:01PM -0500, Santosh Shilimkar wrote:
>> On Thursday 12 December 2013 12:48 PM, Felipe Balbi wrote:
>>> Hi,
>>>
>>> On Tue, Dec 10, 2013 at 10:11:36AM -0500, Santosh Shilimkar wrote:
>>>>>> +static int kdwc3_remove(struct platform_device *pdev)
>>>>>> +{
>>>>>> +	struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
>>>>>> +
>>>>>> +	kdwc3_disable_irqs(kdwc);
>>>>>> +	clk_disable_unprepare(kdwc->clk);
>>>>>
>>>>> I hope the clock isn't shared between core and wrapper, otherwise you
>>>>> could run into some troubles here. Can you confirm ?
>>>>>
>>>> Yes. the clock isn't shared. Thanks for taking care of other parts.
>>>
>>> so clock for core is always running too ?
>>>
>> I take that back. The clock is actually common so we should disable
>> it after removing the  kdwc3_remove_core() as you suggested.
>>
>> You won't see issue since the  kdwc3_remove_core() not doing
>> any register access but moving the clock disable after
>> the core remove is right thing to do.
> 
> the problem is not kdwc3_remove_core() accessing registers, but
> dwc3_remove() _does_ access registers during remove. If you just
> mopdrobe -r dwc3-keystone without removing dwc3.ko first, then
> kdwc3_remove_core() will cause dwc3.ko to be removed (because of
> platform_driver_unregister()) and, since clocks have already been
> disabled, then we'd die :-)
> 
Oh yes, you are right. I see Wingman already posted the updated patch.

Regards,
Santosh
diff mbox

Patch

diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index 70fc430..e2c730f 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -70,6 +70,13 @@  config USB_DWC3_PCI
 	  One such PCIe-based platform is Synopsys' PCIe HAPS model of
 	  this IP.
 
+config USB_DWC3_KEYSTONE
+	tristate "Texas Instruments Keystone2 Platforms"
+	default USB_DWC3
+	help
+	  Support of USB2/3 functionality in TI Keystone2 platforms.
+	  Say 'Y' or 'M' here if you have one such device
+
 comment "Debugging features"
 
 config USB_DWC3_DEBUG
diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
index dd17601..10ac3e7 100644
--- a/drivers/usb/dwc3/Makefile
+++ b/drivers/usb/dwc3/Makefile
@@ -32,3 +32,4 @@  endif
 obj-$(CONFIG_USB_DWC3_OMAP)		+= dwc3-omap.o
 obj-$(CONFIG_USB_DWC3_EXYNOS)		+= dwc3-exynos.o
 obj-$(CONFIG_USB_DWC3_PCI)		+= dwc3-pci.o
+obj-$(CONFIG_USB_DWC3_KEYSTONE)		+= dwc3-keystone.o
diff --git a/drivers/usb/dwc3/dwc3-keystone.c b/drivers/usb/dwc3/dwc3-keystone.c
new file mode 100644
index 0000000..33f71330b
--- /dev/null
+++ b/drivers/usb/dwc3/dwc3-keystone.c
@@ -0,0 +1,205 @@ 
+/**
+ * dwc3-keystone.c - Keystone Specific Glue layer
+ *
+ * Copyright (C) 2010-2013 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * Author: WingMan Kwok <w-kwok2@ti.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  of
+ * the License as published by the Free Software Foundation.
+ *
+ * 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/clk.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/of_platform.h>
+
+/* USBSS register offsets */
+#define USBSS_REVISION		0x0000
+#define USBSS_SYSCONFIG		0x0010
+#define USBSS_IRQ_EOI		0x0018
+#define USBSS_IRQSTATUS_RAW_0	0x0020
+#define USBSS_IRQSTATUS_0	0x0024
+#define USBSS_IRQENABLE_SET_0	0x0028
+#define USBSS_IRQENABLE_CLR_0	0x002c
+
+/* IRQ register bits */
+#define USBSS_IRQ_EOI_LINE(n)	BIT(n)
+#define USBSS_IRQ_EVENT_ST	BIT(0)
+#define USBSS_IRQ_COREIRQ_EN	BIT(0)
+#define USBSS_IRQ_COREIRQ_CLR	BIT(0)
+
+static u64 kdwc3_dma_mask;
+
+struct dwc3_keystone {
+	struct device			*dev;
+	struct clk			*clk;
+	void __iomem			*usbss;
+};
+
+static inline u32 kdwc3_readl(void __iomem *base, u32 offset)
+{
+	return readl(base + offset);
+}
+
+static inline void kdwc3_writel(void __iomem *base, u32 offset, u32 value)
+{
+	writel(value, base + offset);
+}
+
+static void kdwc3_enable_irqs(struct dwc3_keystone *kdwc)
+{
+	u32 val;
+
+	val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
+	val = USBSS_IRQ_COREIRQ_EN;
+	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, val);
+}
+
+static void kdwc3_disable_irqs(struct dwc3_keystone *kdwc)
+{
+	u32 val;
+
+	val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
+	val &= ~USBSS_IRQ_COREIRQ_EN;
+	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, val);
+}
+
+static irqreturn_t dwc3_keystone_interrupt(int irq, void *_kdwc)
+{
+	struct dwc3_keystone	*kdwc = _kdwc;
+
+	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_CLR_0, USBSS_IRQ_COREIRQ_CLR);
+	kdwc3_writel(kdwc->usbss, USBSS_IRQSTATUS_0, USBSS_IRQ_EVENT_ST);
+	kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, USBSS_IRQ_COREIRQ_EN);
+	kdwc3_writel(kdwc->usbss, USBSS_IRQ_EOI, USBSS_IRQ_EOI_LINE(0));
+
+	return IRQ_HANDLED;
+}
+
+static int kdwc3_probe(struct platform_device *pdev)
+{
+	struct device		*dev = &pdev->dev;
+	struct device_node	*node = pdev->dev.of_node;
+	struct dwc3_keystone	*kdwc;
+	struct resource		*res;
+	int			error, irq;
+
+	kdwc = devm_kzalloc(dev, sizeof(*kdwc), GFP_KERNEL);
+	if (!kdwc)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, kdwc);
+
+	kdwc->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "missing usbss resource\n");
+		return -EINVAL;
+	}
+
+	kdwc->usbss = devm_ioremap_resource(dev, res);
+	if (IS_ERR(kdwc->usbss))
+		return PTR_ERR(kdwc->usbss);
+
+	kdwc3_dma_mask = dma_get_mask(dev);
+	dev->dma_mask = &kdwc3_dma_mask;
+
+	kdwc->clk = devm_clk_get(kdwc->dev, "usb");
+	if (IS_ERR_OR_NULL(kdwc->clk)) {
+		dev_err(kdwc->dev, "unable to get kdwc usb clock\n");
+		return -ENODEV;
+	}
+
+	error = clk_prepare_enable(kdwc->clk);
+	if (error < 0) {
+		dev_dbg(kdwc->dev, "unable to enable usb clock, err %d\n",
+			error);
+		return error;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "missing irq\n");
+		goto err_irq;
+	}
+
+	error = devm_request_irq(dev, irq, dwc3_keystone_interrupt, IRQF_SHARED,
+			dev_name(dev), kdwc);
+	if (error) {
+		dev_err(dev, "failed to request IRQ #%d --> %d\n",
+				irq, error);
+		goto err_irq;
+	}
+
+	kdwc3_enable_irqs(kdwc);
+
+	error = of_platform_populate(node, NULL, NULL, dev);
+	if (error) {
+		dev_err(&pdev->dev, "failed to create dwc3 core\n");
+		goto err_core;
+	}
+
+	return 0;
+
+err_core:
+	kdwc3_disable_irqs(kdwc);
+err_irq:
+	clk_disable_unprepare(kdwc->clk);
+
+	return error;
+}
+
+static int kdwc3_remove_core(struct device *dev, void *c)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+
+	platform_device_unregister(pdev);
+
+	return 0;
+}
+
+static int kdwc3_remove(struct platform_device *pdev)
+{
+	struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
+
+	kdwc3_disable_irqs(kdwc);
+	clk_disable_unprepare(kdwc->clk);
+	device_for_each_child(&pdev->dev, NULL, kdwc3_remove_core);
+	platform_set_drvdata(pdev, NULL);
+	return 0;
+}
+
+static const struct of_device_id kdwc3_of_match[] = {
+	{ .compatible = "ti,keystone-dwc3", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, kdwc3_of_match);
+
+static struct platform_driver kdwc3_driver = {
+	.probe		= kdwc3_probe,
+	.remove		= kdwc3_remove,
+	.driver		= {
+		.name	= "keystone-dwc3",
+		.owner	        = THIS_MODULE,
+		.of_match_table	= kdwc3_of_match,
+	},
+};
+
+module_platform_driver(kdwc3_driver);
+
+MODULE_ALIAS("platform:keystone-dwc3");
+MODULE_AUTHOR("WingMan Kwok <w-kwok2@ti.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("DesignWare USB3 KEYSTONE Glue Layer");