i2c: twl4030-usb: add 'vbus' sysfs file

vbus sysfs file will report the state of vbus irq coming from
twl4030-usb.

Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/drivers/i2c/chips/twl4030-usb.c b/drivers/i2c/chips/twl4030-usb.c
index 246aa9d..f530e71 100644 (file)
--- a/drivers/i2c/chips/twl4030-usb.c
+++ b/drivers/i2c/chips/twl4030-usb.c
@@ -29,6 +29,8 @@
 #include <linux/time.h>
 #include <linux/interrupt.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>
@@ -259,11 +261,17 @@
 
 
 struct twl4030_usb {
+       struct work_struct      irq_work;
        struct otg_transceiver  otg;
        struct device           *dev;
 
+       /* for vbus reporting with irqs disabled */
+       spinlock_t              lock;
+
        /* pin configuration */
        enum twl4030_usb_mode   usb_mode;
+
+       unsigned                vbus:1;
        int                     irq;
        u8                      asleep;
 };
@@ -529,6 +537,29 @@ static void twl4030_usb_ldo_init(struct twl4030_usb *twl)
        twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER, 0, PROTECT_KEY);
 }
 
+static ssize_t twl4030_usb_vbus_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct twl4030_usb *twl = dev_get_drvdata(dev);
+       unsigned long flags;
+       int ret = -EINVAL;
+
+       spin_lock_irqsave(&twl->lock, flags);
+       ret = sprintf(buf, "%s\n", twl->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;
@@ -541,10 +572,13 @@ static irqreturn_t twl4030_usb_irq(int irq, void *_twl)
        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);
        }
+       schedule_work(&twl->irq_work);
 
        return IRQ_HANDLED;
 }
@@ -634,6 +668,7 @@ static int __init twl4030_usb_probe(struct platform_device *pdev)
        struct twl4030_usb_data *pdata = pdev->dev.platform_data;
        struct twl4030_usb      *twl;
        int status;
+       u8                      vbus;
 
        twl = kzalloc(sizeof *twl, GFP_KERNEL);
        if (!twl)
@@ -644,12 +679,23 @@ static int __init twl4030_usb_probe(struct platform_device *pdev)
                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                = TWL4030_PWRIRQ_USB_PRES;
        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;
+
+       /* init spinlock for workqueue */
+       spin_lock_init(&twl->lock);
+
+       /* init irq workqueue before request_irq */
+       INIT_WORK(&twl->irq_work, twl4030_usb_irq_work);
 
        usb_irq_disable(twl);
        status = request_irq(twl->irq, twl4030_usb_irq, 0, "twl4030_usb", twl);
@@ -660,7 +706,6 @@ static int __init twl4030_usb_probe(struct platform_device *pdev)
                return status;
        }
 
-
        twl4030_usb_ldo_init(twl);
        twl4030_phy_power(twl, 1);
        twl4030_i2c_access(twl, 1);
@@ -677,6 +722,9 @@ static int __init twl4030_usb_probe(struct platform_device *pdev)
        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;
 }
 
@@ -687,6 +735,7 @@ static int __exit twl4030_usb_remove(struct platform_device *pdev)
 
        usb_irq_disable(twl);
        free_irq(twl->irq, twl);
+       device_remove_file(twl->dev, &dev_attr_vbus);
 
        /* set transceiver mode to power on defaults */
        twl4030_usb_set_mode(twl, -1);