From: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Simplify handling of VBUS and ID status and the USB_PRES interrupt.
This seems to resolve the problems I previously saw on Beagle and
Overo boards.
- Read the status directly, instead of trying to infer it from
dodgey side effects of IRQ handling and trigger tweaking.
- Stop trying to arrange those dodgey side effects; just leave
the IRQ enabled at all times.
- Check that status as part of driver probe, so the PHY can
always be active by the time it's needed. (BUGFIX!)
- Re-sequence probe() to be less racey, and to avoid duplicating
logic found elsewhere (notably irq handling and PHY activation).
- Make the irq_chip be the exclusive owner of PWR_EDR (finally).
- Get rid of needless work_struct ... in this irq handling thread,
it's safe and cheap to call sysfs_notify() directly.
Stop enabling IRQs on the USB subchip. There's no IRQ handler for
them, and since ALT_INT_REROUTE isn't being set they'll never
arrive ... so there's no point to enabling them.
Also add some comments about other things such an otg_transciever
driver should be doing, fixing minor omissions; and remove some
unnecessary file inclusions.
Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
---
NOTE: applies on top of the previous patches updating IRQ
handling and creating drivers/mfd/twl4030-irq.c ...
drivers/i2c/chips/twl4030-usb.c | 209 ++++++++++++++++++--------------------
1 file changed, 104 insertions(+), 105 deletions(-)
--- a/drivers/i2c/chips/twl4030-usb.c
+++ b/drivers/i2c/chips/twl4030-usb.c
@@ -26,16 +26,12 @@
#include <linux/module.h>
#include <linux/init.h>
-#include <linux/time.h>
#include <linux/interrupt.h>
-#include <linux/irq.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/io.h>
-#include <linux/usb.h>
-#include <linux/usb/ch9.h>
-#include <linux/usb/gadget.h>
+#include <linux/delay.h>
#include <linux/usb/otg.h>
#include <linux/i2c/twl4030.h>
#include <mach/usb.h>
@@ -237,10 +233,6 @@
#define PMBR1 0x0D
#define GPIO_USB_4PIN_ULPI_2430C (3 << 0)
-/* In module TWL4030_MODULE_INT */
-#define REG_PWR_EDR1 0x05
-#define USB_PRES_FALLING (1 << 4)
-#define USB_PRES_RISING (1 << 5)
/* bits in OTG_CTRL */
#define OTG_XCEIV_OUTPUTS \
@@ -256,8 +248,14 @@
OTG_CTRL_BITS)
+enum linkstat {
+ USB_LINK_UNKNOWN = 0,
+ USB_LINK_NONE,
+ USB_LINK_VBUS,
+ USB_LINK_ID,
+};
+
struct twl4030_usb {
- struct work_struct irq_work;
struct otg_transceiver otg;
struct device *dev;
@@ -267,8 +265,8 @@ struct twl4030_usb {
/* pin configuration */
enum twl4030_usb_mode usb_mode;
- unsigned vbus:1;
int irq;
+ u8 linkstat;
u8 asleep;
bool irq_enabled;
};
@@ -326,21 +324,27 @@ static inline int twl4030_usb_write(stru
return ret;
}
-static inline int twl4030_usb_read(struct twl4030_usb *twl, u8 address)
+static inline int twl4030_readb(struct twl4030_usb *twl, u8 module, u8 address)
{
u8 data;
int ret = 0;
- ret = twl4030_i2c_read_u8(TWL4030_MODULE_USB, &data, address);
+ ret = twl4030_i2c_read_u8(module, &data, address);
if (ret >= 0)
ret = data;
else
dev_warn(twl->dev,
- "TWL4030:USB:Read[0x%x] Error %d\n", address, ret);
+ "TWL4030:readb[0x%x,0x%x] Error %d\n",
+ module, address, ret);
return ret;
}
+static inline int twl4030_usb_read(struct twl4030_usb *twl, u8 address)
+{
+ return twl4030_readb(twl, TWL4030_MODULE_USB, address);
+}
+
/*-------------------------------------------------------------------------*/
static inline int
@@ -357,6 +361,39 @@ twl4030_usb_clear_bits(struct twl4030_us
/*-------------------------------------------------------------------------*/
+static enum linkstat twl4030_usb_linkstat(struct twl4030_usb *twl)
+{
+ int status;
+ int linkstat = USB_LINK_UNKNOWN;
+
+ /* STS_HW_CONDITIONS */
+ status = twl4030_readb(twl, TWL4030_MODULE_PM_MASTER, 0x0f);
+ if (status < 0)
+ dev_err(twl->dev, "USB link status err %d\n", status);
+ else if (status & BIT(7))
+ linkstat = USB_LINK_VBUS;
+ else if (status & BIT(2))
+ linkstat = USB_LINK_ID;
+ else
+ linkstat = USB_LINK_NONE;
+
+ dev_dbg(twl->dev, "HW_CONDITIONS 0x%02x/%d; link %d\n",
+ status, status, linkstat);
+
+ spin_lock_irq(&twl->lock);
+ twl->linkstat = linkstat;
+ if (linkstat == USB_LINK_ID) {
+ twl->otg.default_a = true;
+ twl->otg.state = OTG_STATE_A_IDLE;
+ } else {
+ twl->otg.default_a = false;
+ twl->otg.state = OTG_STATE_B_IDLE;
+ }
+ spin_unlock_irq(&twl->lock);
+
+ return linkstat;
+}
+
static void twl4030_usb_set_mode(struct twl4030_usb *twl, int mode)
{
twl->usb_mode = mode;
@@ -410,24 +447,6 @@ static void twl4030_i2c_access(struct tw
}
}
-static void usb_irq_enable(struct twl4030_usb *twl, int trigger)
-{
- set_irq_type(twl->irq, trigger);
-
- if (!twl->irq_enabled) {
- enable_irq(twl->irq);
- twl->irq_enabled = true;
- }
-}
-
-static void usb_irq_disable(struct twl4030_usb *twl)
-{
- if (twl->irq_enabled) {
- disable_irq(twl->irq);
- twl->irq_enabled = false;
- }
-}
-
static void twl4030_phy_power(struct twl4030_usb *twl, int on)
{
u8 pwr;
@@ -448,16 +467,9 @@ static void twl4030_phy_power(struct twl
static void twl4030_phy_suspend(struct twl4030_usb *twl, int controller_off)
{
- if (controller_off)
- usb_irq_disable(twl);
-
if (twl->asleep)
return;
- if (!controller_off)
- /* enable rising edge interrupt to detect cable attach */
- usb_irq_enable(twl, IRQ_TYPE_EDGE_RISING);
-
twl4030_phy_power(twl, 0);
twl->asleep = 1;
}
@@ -467,9 +479,6 @@ static void twl4030_phy_resume(struct tw
if (!twl->asleep)
return;
- /* enable falling edge interrupt to detect cable detach */
- usb_irq_enable(twl, IRQ_TYPE_EDGE_FALLING);
-
twl4030_phy_power(twl, 1);
twl4030_i2c_access(twl, 1);
twl4030_usb_set_mode(twl, twl->usb_mode);
@@ -514,25 +523,18 @@ static ssize_t twl4030_usb_vbus_show(str
int ret = -EINVAL;
spin_lock_irqsave(&twl->lock, flags);
- ret = sprintf(buf, "%s\n", twl->vbus ? "on" : "off");
+ ret = sprintf(buf, "%s\n",
+ (twl->linkstat == USB_LINK_VBUS) ? "on" : "off");
spin_unlock_irqrestore(&twl->lock, flags);
return ret;
}
static DEVICE_ATTR(vbus, 0444, twl4030_usb_vbus_show, NULL);
-static void twl4030_usb_irq_work(struct work_struct *work)
-{
- struct twl4030_usb *twl = container_of(work,
- struct twl4030_usb, irq_work);
-
- sysfs_notify(&twl->dev->kobj, NULL, "vbus");
-}
-
static irqreturn_t twl4030_usb_irq(int irq, void *_twl)
{
struct twl4030_usb *twl = _twl;
- u8 val;
+ int status;
#ifdef CONFIG_LOCKDEP
/* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
@@ -542,27 +544,28 @@ static irqreturn_t twl4030_usb_irq(int i
local_irq_enable();
#endif
- /* FIXME stop accessing PWR_EDR1 ... if nothing else, we
- * know which edges we told the IRQ to trigger on. And
- * there seem to be OTG_specific registers and irqs that
- * provide the right info without guessing like this:
- * USB_INT_STS, ID_STATUS, STS_HW_CONDITIONS, etc.
- */
+ status = twl4030_usb_linkstat(twl);
+ if (status != USB_LINK_UNKNOWN) {
- /* action based on cable attach or detach */
- WARN_ON(twl4030_i2c_read_u8(TWL4030_MODULE_INT,
- &val, REG_PWR_EDR1) < 0);
+ /* FIXME add a set_power() method so that B-devices can
+ * configure the charger appropriately. It's not always
+ * correct to consume VBUS power, and how much current to
+ * consume is a function of the USB configuration chosen
+ * by the host.
+ *
+ * REVISIT usb_gadget_vbus_connect(...) as needed, ditto
+ * its disconnect() sibling, when changing to/from the
+ * USB_LINK_VBUS state. musb_hdrc won't care until it
+ * starts to handle softconnect right.
+ */
+ twl4030charger_usb_en(status == USB_LINK_VBUS);
- if (val & USB_PRES_RISING) {
- twl4030_phy_resume(twl);
- twl4030charger_usb_en(1);
- twl->vbus = 1;
- } else {
- twl4030charger_usb_en(0);
- twl->vbus = 0;
- twl4030_phy_suspend(twl, 0);
+ if (status == USB_LINK_NONE)
+ twl4030_phy_suspend(twl, 0);
+ else
+ twl4030_phy_resume(twl);
}
- schedule_work(&twl->irq_work);
+ sysfs_notify(&twl->dev->kobj, NULL, "vbus");
return IRQ_HANDLED;
}
@@ -608,11 +611,6 @@ static int twl4030_set_peripheral(struct
twl->otg.state = OTG_STATE_B_IDLE;
- twl4030_usb_set_bits(twl, USB_INT_EN_RISE,
- USB_INT_SESSVALID | USB_INT_VBUSVALID);
- twl4030_usb_set_bits(twl, USB_INT_EN_FALL,
- USB_INT_SESSVALID | USB_INT_VBUSVALID);
-
return 0;
}
@@ -639,8 +637,7 @@ static int twl4030_set_host(struct otg_t
twl4030_usb_set_bits(twl, TWL4030_OTG_CTRL,
TWL4030_OTG_CTRL_DMPULLDOWN
| TWL4030_OTG_CTRL_DPPULLDOWN);
- twl4030_usb_set_bits(twl, USB_INT_EN_RISE, USB_INT_IDGND);
- twl4030_usb_set_bits(twl, USB_INT_EN_FALL, USB_INT_IDGND);
+
twl4030_usb_set_bits(twl, FUNC_CTRL, FUNC_CTRL_SUSPENDM);
twl4030_usb_set_bits(twl, TWL4030_OTG_CTRL, TWL4030_OTG_CTRL_DRVVBUS);
@@ -651,8 +648,7 @@ static int __init twl4030_usb_probe(stru
{
struct twl4030_usb_data *pdata = pdev->dev.platform_data;
struct twl4030_usb *twl;
- int status;
- u8 vbus;
+ int status;
twl = kzalloc(sizeof *twl, GFP_KERNEL);
if (!twl)
@@ -663,26 +659,38 @@ static int __init twl4030_usb_probe(stru
return -EINVAL;
}
- WARN_ON(twl4030_i2c_read_u8(TWL4030_MODULE_INT,
- &vbus, REG_PWR_EDR1) < 0);
- vbus &= USB_PRES_RISING;
-
twl->dev = &pdev->dev;
twl->irq = platform_get_irq(pdev, 0);
+ twl->otg.dev = twl->dev;
+ twl->otg.label = "twl4030";
twl->otg.set_host = twl4030_set_host;
twl->otg.set_peripheral = twl4030_set_peripheral;
twl->otg.set_suspend = twl4030_set_suspend;
twl->usb_mode = pdata->usb_mode;
- twl->vbus = vbus ? 1 : 0;
+ twl->asleep = 1;
/* init spinlock for workqueue */
spin_lock_init(&twl->lock);
- /* init irq workqueue before request_irq */
- INIT_WORK(&twl->irq_work, twl4030_usb_irq_work);
+ twl4030_usb_ldo_init(twl);
+ otg_set_transceiver(&twl->otg);
+
+ platform_set_drvdata(pdev, twl);
+ if (device_create_file(&pdev->dev, &dev_attr_vbus))
+ dev_warn(&pdev->dev, "could not create sysfs file\n");
+ /* Our job is to use irqs and status from the power module
+ * to keep the transceiver disabled when nothing's connected.
+ *
+ * FIXME we actually shouldn't start enabling it until the
+ * USB controller drivers have said they're ready, by calling
+ * set_host() and/or set_peripheral() ... OTG_capable boards
+ * need both handles, otherwise just one suffices.
+ */
twl->irq_enabled = true;
- status = request_irq(twl->irq, twl4030_usb_irq, 0, "twl4030_usb", twl);
+ status = request_irq(twl->irq, twl4030_usb_irq,
+ IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
+ "twl4030_usb", twl);
if (status < 0) {
dev_dbg(&pdev->dev, "can't get IRQ %d, err %d\n",
twl->irq, status);
@@ -690,25 +698,17 @@ static int __init twl4030_usb_probe(stru
return status;
}
- twl4030_usb_ldo_init(twl);
- twl4030_phy_power(twl, 1);
- twl4030_i2c_access(twl, 1);
- twl4030_usb_set_mode(twl, twl->usb_mode);
-
- twl->asleep = 0;
-
- if (twl->usb_mode == T2_USB_MODE_ULPI) {
- twl4030_i2c_access(twl, 0);
- twl4030_phy_suspend(twl, 0);
- }
+ /* The IRQ handler just handles changes from the previous states
+ * of the ID and VBUS pins ... in probe() we must initialize that
+ * previous state. The easy way: fake an IRQ.
+ *
+ * REVISIT: a real IRQ might have happened already, if PREEMPT is
+ * enabled. Else the IRQ may not yet be configured or enabled,
+ * because of scheduling delays.
+ */
+ twl4030_usb_irq(twl->irq, twl);
- otg_set_transceiver(&twl->otg);
- platform_set_drvdata(pdev, twl);
dev_info(&pdev->dev, "Initialized TWL4030 USB module\n");
-
- if (device_create_file(&pdev->dev, &dev_attr_vbus))
- dev_warn(&pdev->dev, "could not create sysfs file\n");
-
return 0;
}
@@ -717,7 +717,6 @@ static int __exit twl4030_usb_remove(str
struct twl4030_usb *twl = platform_get_drvdata(pdev);
int val;
- usb_irq_disable(twl);
free_irq(twl->irq, twl);
device_remove_file(twl->dev, &dev_attr_vbus);
--
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