Re: [PATCH v4] usb: dwc3: use extcon fwrk to receive connect/disconnect

From: Kishon Vijay Abraham I
Date: Thu Jun 20 2013 - 04:55:18 EST

Hi,

On Monday 17 June 2013 09:39 AM, Chanwoo Choi wrote:
On 06/14/2013 10:10 PM, Kishon Vijay Abraham I wrote:
Modified dwc3-omap to receive connect and disconnect notification using
extcon framework. Also did the necessary cleanups required after
adapting to extcon framework.

Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
Acked-by: Felipe Balbi <balbi@xxxxxx>
---
This patch depends on
git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/extcon.git commit:f7ae906

It should also be applied on top of
usb: dwc3: omap: improve error handling of dwc3_omap_probe patch which is
merged in Felipe's tree.

So I'm not sure on whose tree this patch should go in.

Changes from v3:
* did #include of of_extcon.h after Chanwoo resent the patch separating
extcon-class.c from of_extcon.c
Changes from v2:
* updated the Documentation with dwc3 dt binding information.
* used of_extcon_get_extcon_dev to get extcon device from device tree data.
Changes from v1:
* regulator enable/disable is now done here instead of palmas-usb as some users
of palmas-usb wont need regulator.

Documentation/devicetree/bindings/usb/omap-usb.txt | 5 +
drivers/usb/dwc3/dwc3-omap.c | 119 ++++++++++++++++----
include/linux/usb/dwc3-omap.h | 30 -----
3 files changed, 105 insertions(+), 49 deletions(-)
delete mode 100644 include/linux/usb/dwc3-omap.h

diff --git a/Documentation/devicetree/bindings/usb/omap-usb.txt b/Documentation/devicetree/bindings/usb/omap-usb.txt
index d4769f3..f1c15f3 100644
--- a/Documentation/devicetree/bindings/usb/omap-usb.txt
+++ b/Documentation/devicetree/bindings/usb/omap-usb.txt
@@ -53,6 +53,11 @@ OMAP DWC3 GLUE
It should be set to "1" for HW mode and "2" for SW mode.
- ranges: the child address space are mapped 1:1 onto the parent address space

+Optional Properties:
+ - extcon : phandle for the extcon device omap dwc3 uses to detect
+ connect/disconnect events.
+ - vbus-supply : phandle to the regulator device tree node if needed.
+
Sub-nodes:
The dwc3 core should be added as subnode to omap dwc3 glue.
- dwc3 :
diff --git a/drivers/usb/dwc3/dwc3-omap.c b/drivers/usb/dwc3/dwc3-omap.c
index f8f76e6..14c1f1b 100644
--- a/drivers/usb/dwc3/dwc3-omap.c
+++ b/drivers/usb/dwc3/dwc3-omap.c
@@ -43,13 +43,15 @@
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/platform_data/dwc3-omap.h>
-#include <linux/usb/dwc3-omap.h>
#include <linux/pm_runtime.h>
#include <linux/dma-mapping.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_platform.h>
+#include <linux/extcon.h>
+#include <linux/extcon/of_extcon.h>
+#include <linux/regulator/consumer.h>

#include <linux/usb/otg.h>

@@ -124,9 +126,21 @@ struct dwc3_omap {
u32 utmi_otg_status;

u32 dma_status:1;
+
+ struct extcon_specific_cable_nb extcon_vbus_dev;
+ struct extcon_specific_cable_nb extcon_id_dev;
+ struct notifier_block vbus_nb;
+ struct notifier_block id_nb;
+
+ struct regulator *vbus_reg;
};

-static struct dwc3_omap *_omap;
+enum omap_dwc3_vbus_id_status {
+ OMAP_DWC3_ID_FLOAT,
+ OMAP_DWC3_ID_GROUND,
+ OMAP_DWC3_VBUS_OFF,
+ OMAP_DWC3_VBUS_VALID,
+};

static inline u32 dwc3_omap_readl(void __iomem *base, u32 offset)
{
@@ -138,18 +152,23 @@ static inline void dwc3_omap_writel(void __iomem *base, u32 offset, u32 value)
writel(value, base + offset);
}

-int dwc3_omap_mailbox(enum omap_dwc3_vbus_id_status status)
+static void dwc3_omap_set_mailbox(struct dwc3_omap *omap,
+ enum omap_dwc3_vbus_id_status status)
{
- u32 val;
- struct dwc3_omap *omap = _omap;
-
- if (!omap)
- return -EPROBE_DEFER;
+ int ret;
+ u32 val;

switch (status) {
case OMAP_DWC3_ID_GROUND:
dev_dbg(omap->dev, "ID GND\n");

+ if (omap->vbus_reg) {
+ ret = regulator_enable(omap->vbus_reg);
+ if (ret) {
+ dev_dbg(omap->dev, "regulator enable failed\n");
+ return;
+ }
+ }
val = dwc3_omap_readl(omap->base, USBOTGSS_UTMI_OTG_STATUS);
val &= ~(USBOTGSS_UTMI_OTG_STATUS_IDDIG
| USBOTGSS_UTMI_OTG_STATUS_VBUSVALID
@@ -172,6 +191,9 @@ int dwc3_omap_mailbox(enum omap_dwc3_vbus_id_status status)
break;

case OMAP_DWC3_ID_FLOAT:
+ if (omap->vbus_reg)
+ regulator_disable(omap->vbus_reg);
+
case OMAP_DWC3_VBUS_OFF:
dev_dbg(omap->dev, "VBUS Disconnect\n");

@@ -185,12 +207,9 @@ int dwc3_omap_mailbox(enum omap_dwc3_vbus_id_status status)
break;

default:
- dev_dbg(omap->dev, "ID float\n");
+ dev_dbg(omap->dev, "invalid state\n");
}
-
- return 0;
}
-EXPORT_SYMBOL_GPL(dwc3_omap_mailbox);

static irqreturn_t dwc3_omap_interrupt(int irq, void *_omap)
{
@@ -282,6 +301,32 @@ static void dwc3_omap_disable_irqs(struct dwc3_omap *omap)

static u64 dwc3_omap_dma_mask = DMA_BIT_MASK(32);

+static int dwc3_omap_id_notifier(struct notifier_block *nb,
+ unsigned long event, void *ptr)
+{
+ struct dwc3_omap *omap = container_of(nb, struct dwc3_omap, id_nb);
+
+ if (event)
+ dwc3_omap_set_mailbox(omap, OMAP_DWC3_ID_GROUND);
+ else
+ dwc3_omap_set_mailbox(omap, OMAP_DWC3_ID_FLOAT);
+
+ return NOTIFY_DONE;
+}
+
+static int dwc3_omap_vbus_notifier(struct notifier_block *nb,
+ unsigned long event, void *ptr)
+{
+ struct dwc3_omap *omap = container_of(nb, struct dwc3_omap, vbus_nb);
+
+ if (event)
+ dwc3_omap_set_mailbox(omap, OMAP_DWC3_VBUS_VALID);
+ else
+ dwc3_omap_set_mailbox(omap, OMAP_DWC3_VBUS_OFF);
+
+ return NOTIFY_DONE;
+}
+
static int dwc3_omap_probe(struct platform_device *pdev)
{
struct device_node *node = pdev->dev.of_node;
@@ -289,6 +334,8 @@ static int dwc3_omap_probe(struct platform_device *pdev)
struct dwc3_omap *omap;
struct resource *res;
struct device *dev = &pdev->dev;
+ struct extcon_dev *edev;
+ struct regulator *vbus_reg = NULL;

int ret = -ENOMEM;
int irq;
@@ -330,19 +377,22 @@ static int dwc3_omap_probe(struct platform_device *pdev)
return -ENOMEM;
}

+ if (of_property_read_bool(node, "vbus-supply")) {
+ vbus_reg = devm_regulator_get(dev, "vbus");
+ if (IS_ERR(vbus_reg)) {
+ dev_err(dev, "vbus init failed\n");
+ return PTR_ERR(vbus_reg);
+ }
+ }
+
spin_lock_init(&omap->lock);

omap->dev = dev;
omap->irq = irq;
omap->base = base;
+ omap->vbus_reg = vbus_reg;
dev->dma_mask = &dwc3_omap_dma_mask;

- /*
- * REVISIT if we ever have two instances of the wrapper, we will be
- * in big trouble
- */
- _omap = omap;
-
pm_runtime_enable(dev);
ret = pm_runtime_get_sync(dev);
if (ret < 0) {
@@ -381,14 +431,41 @@ static int dwc3_omap_probe(struct platform_device *pdev)

dwc3_omap_enable_irqs(omap);

+ if (of_property_read_bool(node, "extcon")) {
+ edev = of_extcon_get_extcon_dev(dev, 0);
+ if (IS_ERR(edev)) {
+ dev_vdbg(dev, "couldn't get extcon device\n");
+ ret = PTR_ERR(edev);
+ goto err2;
+ }
+
+ omap->vbus_nb.notifier_call = dwc3_omap_vbus_notifier;
+ extcon_register_interest(&omap->extcon_vbus_dev, edev->name,
+ "USB", &omap->vbus_nb);
+ omap->id_nb.notifier_call = dwc3_omap_id_notifier;
+ extcon_register_interest(&omap->extcon_id_dev, edev->name,
+ "USB-HOST", &omap->id_nb);

I prefer adding exception handling code about return value of extcon_register_interest().

+
+ if (extcon_get_cable_state(edev, "USB") == true)
+ dwc3_omap_set_mailbox(omap, OMAP_DWC3_VBUS_VALID);
+ if (extcon_get_cable_state(edev, "USB-HOST") == true)
+ dwc3_omap_set_mailbox(omap, OMAP_DWC3_ID_GROUND);
+ }
+
ret = of_platform_populate(node, NULL, NULL, dev);
if (ret) {
dev_err(&pdev->dev, "failed to create dwc3 core\n");
- goto err2;
+ goto err3;
}

return 0;

+err3:
+ if (omap->extcon_vbus_dev.edev)
+ extcon_unregister_interest(&omap->extcon_vbus_dev);
+ if (omap->extcon_id_dev.edev)
+ extcon_unregister_interest(&omap->extcon_id_dev);
+
err2:
dwc3_omap_disable_irqs(omap);

@@ -405,6 +482,10 @@ static int dwc3_omap_remove(struct platform_device *pdev)
{
struct dwc3_omap *omap = platform_get_drvdata(pdev);

+ if (omap->extcon_vbus_dev.edev)
+ extcon_unregister_interest(&omap->extcon_vbus_dev);
+ if (omap->extcon_id_dev.edev)
+ extcon_unregister_interest(&omap->extcon_id_dev);
dwc3_omap_disable_irqs(omap);
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
diff --git a/include/linux/usb/dwc3-omap.h b/include/linux/usb/dwc3-omap.h
deleted file mode 100644
index 5615f4d..0000000


It looks good if you add exception handler about return value of extcon_register_interest().

Ok. I'll fix exception handler and also add depend on of EXTCON here.

Thanks
Kishon
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/