Commit 3b563b90 authored by Dan Drown's avatar Dan Drown Committed by Greg Kroah-Hartman
Browse files

usb: cdc-acm: add PPS support 



This patch adds support for PPS to CDC devices. Changes to the DCD pin
are monitored and passed to the ldisc system, which is used by
pps-ldisc.

Signed-off-by: default avatarDan Drown <dan-netdev@drown.org>
Link: https://lore.kernel.org/r/ZM8ExV6bAvJtIA1d@vps3.drown.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d9216d3e

drivers/usb/class/cdc-acm.c

+11 −1
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <linux/serial.h>

#include <linux/tty_driver.h>

#include <linux/tty_flip.h>

#include <linux/tty_ldisc.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/uaccess.h>
@@ -324,8 +325,17 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf) 


		if (difference & USB_CDC_SERIAL_STATE_DSR)

			acm->iocount.dsr++;

		if (difference & USB_CDC_SERIAL_STATE_DCD)

		if (difference & USB_CDC_SERIAL_STATE_DCD) {

			if (acm->port.tty) {

				struct tty_ldisc *ld = tty_ldisc_ref(acm->port.tty);

				if (ld) {

					if (ld->ops->dcd_change)

						ld->ops->dcd_change(acm->port.tty, newctrl & USB_CDC_SERIAL_STATE_DCD);

					tty_ldisc_deref(ld);

				}

			}

			acm->iocount.dcd++;

		}

		if (newctrl & USB_CDC_SERIAL_STATE_BREAK) {

			acm->iocount.brk++;

			tty_insert_flip_char(&acm->port, 0, TTY_BREAK);