Chanwoo,
On 27/05/15 15:15, Chanwoo Choi wrote:
Previously, I discussed how to inform the changed state of both ID
and VBUS pin for USB connector on patch-set[1].
[1] https://lkml.org/lkml/2015/4/2/310
So, this patch adds the extcon_set_cable_line_state() function to inform
the additional state of external connectors without additional register/
unregister functions. This function uses the existing notifier chain
which is registered by extcon_register_notifier() / extcon_register_interest().
The extcon_set_cable_line_state() can inform the new state of both
ID and VBUS pin state through extcon_set_cable_line_state().
For exmaple:
- On extcon-usb-gpio.c as extcon provider driver as following:
static void usb_extcon_detect_cable(struct work_struct *work)
{
...
/* check ID and update cable state */
id = gpiod_get_value_cansleep(info->id_gpiod);
if (id) {
extcon_set_cable_state_(info->edev, EXTCON_USB_HOST,
false);
Now that all USB line states can be captured by a single cable type
can we get rid of EXTCON_USB_HOST?
That way the extcon driver doesn't need to make any decisions as to
what mode we're in (host/cable) and this is best left to the USB driver.
cheers,
-roger
extcon_set_cable_state_(info->edev, EXTCON_USB, true);
extcon_set_cable_line_state(info->edev, EXTCON_USB,
EXTCON_USB_ID_HIGH);
} else {
extcon_set_cable_state_(info->edev, EXTCON_USB, false);
extcon_set_cable_state_(info->edev, EXTCON_USB_HOST,
true);
extcon_set_cable_line_state(info->edev, EXTCON_USB,
EXTCON_USB_ID_LOW);
}
}
- On specific extcon consumder driver as following:
static int xxx_probe(struct platform_device *pdev)
{
struct notifier_chain nh;
nb.notifier_call = extcon_usb_notifier;
ret = extcon_register_notifier(edev, EXTCON_USB, &nb);
...
}
static int extcon_usb_notifier(struct notifier_block *self,
unsigned long event, void *ptr)
{
switch (event) {
case EXTCON_DETACHED:
printk("USB is detached\n");
break;
case EXTCON_ATTACHED:
printk("USB is attached\n");
break;
case EXTCON_USB_ID_LOW:
printk("USB's ID pin is low state\n");
break;
case EXTCON_USB_ID_HIGH:
printk("USB's ID pin is high state\n");
break;
case EXTCON_USB_VBUS_LOW:
printk("USB's VBUS pin is high state\n");
break;
case EXTCON_USB_VBUS_HIGH:
printk("USB's VBUS pin is high state\n");
break;
default:
return -EINVAL;
};
}
Changes from v1:
- Use dev_warn() instead of dev_info() if set the same extcon_line_state value.
Chanwoo Choi (2):
extcon: Add extcon_set_cable_line_state() to inform the additional state of
external connectors
extcon: usb-gpio: Update the ID pin state of USB when cable state is changed
drivers/extcon/extcon-usb-gpio.c | 6 ++++
drivers/extcon/extcon.c | 74 +++++++++++++++++++++++++++++++++++++++-
include/linux/extcon.h | 24 +++++++++++++
3 files changed, 103 insertions(+), 1 deletion(-)
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