On Thu, Oct 19, 2023 at 01:28:09PM +0200, Florian Eckert wrote:
> Until now, the LED blinks when data is sent via the tty (rx/tx).
> The serial tty interface also supports additional input signals, that can
> also be evaluated within this trigger. This change is adding the following
> additional input sources, which could be controlled
> via the '/sys/class/<leds>/' sysfs interface.
>
> - line_cts:
> DCE is ready to accept data from the DTE (CTS = Clear To Send). If the
> line state is detected, the LED is switched on.
> If set to 0 (default), the LED will not evaluate CTS.
> If set to 1, the LED will evaluate CTS.
>
> - line_dsr:
> DCE is ready to receive and send data (DSR = Data Set Ready). If the line
> state is detected, the LED is switched on.
> If set to 0 (default), the LED will not evaluate DSR.
> If set to 1, the LED will evaluate DSR.
>
> - line_car:
> DTE is receiving a carrier from the DCE (DCD = Data Carrier Detect). If
> the line state is detected, the LED is switched on.
> If set to 0 (default), the LED will not evaluate CAR (DCD).
> If set to 1, the LED will evaluate CAR (DCD).
>
> - line_rng:
> DCE has detected an incoming ring signal on the telephone line
> (RI = Ring Indicator). If the line state is detected, the LED is
> switched on.
> If set to 0 (default), the LED will not evaluate RNG (RI).
> If set to 1, the LED will evaluate RNG (RI).
>
> Explanation:
> DCE = Data Communication Equipment (Modem)
> DTE = Data Terminal Equipment (Computer)
>
> In addition to the new line_* entries in sysfs, the indication for the
> direction of the transmitted data is independently controllable via the
> new rx and tx sysfs entrie now too. These are on by default. Thus the
> trigger behaves as before this change.
>
> - rx:
> Signal reception (rx) of data on the named tty device.
> If set to 0, the LED will not blink on reception.
> If set to 1 (default), the LED will blink on reception.
>
> - tx:
> Signal transmission (tx) of data on the named tty device.
> If set to 0, the LED will not blink on transmission.
> If set to 1 (default), the LED will blink on transmission.
>
> Signed-off-by: Florian Eckert <fe@xxxxxxxxxx>
> ---
> .../ABI/testing/sysfs-class-led-trigger-tty | 54 +++++
> drivers/leds/trigger/ledtrig-tty.c | 192 +++++++++++++++++-
> 2 files changed, 235 insertions(+), 11 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-class-led-trigger-tty b/Documentation/ABI/testing/sysfs-class-led-trigger-tty
> index 2bf6b24e781b..08127b1a4602 100644
> --- a/Documentation/ABI/testing/sysfs-class-led-trigger-tty
> +++ b/Documentation/ABI/testing/sysfs-class-led-trigger-tty
> @@ -4,3 +4,57 @@ KernelVersion: 5.10
> Contact: linux-leds@xxxxxxxxxxxxxxx
> Description:
> Specifies the tty device name of the triggering tty
> +
> +What: /sys/class/leds/<led>/rx
> +Date: October 2023
> +KernelVersion: 6.7
> +Description:
> + Signal reception (rx) of data on the named tty device.
> + If set to 0, the LED will not blink on reception.
> + If set to 1 (default), the LED will blink on reception.
> +
> +What: /sys/class/leds/<led>/tx
> +Date: October 2023
> +KernelVersion: 6.7
> +Description:
> + Signal transmission (tx) of data on the named tty device.
> + If set to 0, the LED will not blink on transmission.
> + If set to 1 (default), the LED will blink on transmission.
> +
> +car rng
> +What: /sys/class/leds/<led>/line_cts
> +Date: October 2023
> +KernelVersion: 6.7
> +Description:
> + DCE is ready to accept data from the DTE (Clear To Send). If
> + the line state is detected, the LED is switched on.
> + If set to 0 (default), the LED will not evaluate CTS.
> + If set to 1, the LED will evaluate CTS.
> +
> +What: /sys/class/leds/<led>/line_dsr
> +Date: October 2023
> +KernelVersion: 6.7
> +Description:
> + DCE is ready to receive and send data (Data Set Ready). If
> + the line state is detected, the LED is switched on.
> + If set to 0 (default), the LED will not evaluate DSR.
> + If set to 1, the LED will evaluate DSR.
> +
> +What: /sys/class/leds/<led>/line_car
> +Date: October 2023
> +KernelVersion: 6.7
> +Description:
> + DTE is receiving a carrier from the DCE (Data Carrier Detect).
> + If the line state is detected, the LED is switched on.
> + If set to 0 (default), the LED will not evaluate CAR (DCD).
> + If set to 1, the LED will evaluate CAR (DCD).
> +
> +What: /sys/class/leds/<led>/line_cts
> +Date: October 2023
> +KernelVersion: 6.7
> +Description:
> + DCE has detected an incoming ring signal on the telephone
> + line (Ring Indicator). If the line state is detected, the
> + LED is switched on.
> + If set to 0 (default), the LED will not evaluate RNG (RI).
> + If set to 1, the LED will evaluate RNG (RI).
> diff --git a/drivers/leds/trigger/ledtrig-tty.c b/drivers/leds/trigger/ledtrig-tty.c
> index 8ae0d2d284af..6a96439a7e55 100644
> --- a/drivers/leds/trigger/ledtrig-tty.c
> +++ b/drivers/leds/trigger/ledtrig-tty.c
> @@ -16,6 +16,24 @@ struct ledtrig_tty_data {
> const char *ttyname;
> struct tty_struct *tty;
> int rx, tx;
> + unsigned long mode;
Why is mode "unsigned long" when the tty layer treats it as an int? And
really, this should be set to an explit size, u32 perhaps? Or am I
confused as to exactly what this is?
> +};
> +
> +enum led_trigger_tty_state {
> + TTY_LED_BLINK,
> + TTY_LED_ENABLE,
> + TTY_LED_DISABLE,
> +};
> +
> +enum led_trigger_tty_modes {
> + TRIGGER_TTY_RX = 0,
> + TRIGGER_TTY_TX,
> + TRIGGER_TTY_CTS,
> + TRIGGER_TTY_DSR,
> + TRIGGER_TTY_CAR,
> + TRIGGER_TTY_RNG,
> + /* Keep last */
> + __TRIGGER_TTY_MAX,
> };
>
Oh wait, is "mode" this? If so, why not define it as an enum? Or if
not, I'm totally confused as to what is going on here, sorry.
> static void ledtrig_tty_restart(struct ledtrig_tty_data *trigger_data)
> @@ -78,13 +96,106 @@ static ssize_t ttyname_store(struct device *dev,
> }
> static DEVICE_ATTR_RW(ttyname);
>
> +static ssize_t ledtrig_tty_attr_show(struct device *dev, char *buf,
> + enum led_trigger_tty_modes attr)
> +{
> + struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev);
> + int bit;
> +
> + switch (attr) {
> + case TRIGGER_TTY_RX:
> + case TRIGGER_TTY_TX:
> + case TRIGGER_TTY_CTS:
> + case TRIGGER_TTY_DSR:
> + case TRIGGER_TTY_CAR:
> + case TRIGGER_TTY_RNG:
> + bit = attr;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
sysfs_emit() for all new sysfs attributes please.
> +}
> +
> +static ssize_t ledtrig_tty_attr_store(struct device *dev, const char *buf,
> + size_t size, enum led_trigger_tty_modes attr)
> +{
> + struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev);
> + unsigned long state;
> + int ret;
> + int bit;
> +
> + ret = kstrtoul(buf, 0, &state);
> + if (ret)
> + return ret;
> +
> + switch (attr) {
> + case TRIGGER_TTY_RX:
> + case TRIGGER_TTY_TX:
> + case TRIGGER_TTY_CTS:
> + case TRIGGER_TTY_DSR:
> + case TRIGGER_TTY_CAR:
> + case TRIGGER_TTY_RNG:
> + bit = attr;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + if (state)
> + set_bit(bit, &trigger_data->mode);
> + else
> + clear_bit(bit, &trigger_data->mode);
I think your test of "state" here is wrong, if you write in "40000" you
are treating it as "1", which I don't think you want, right?
thanks,
greg k-h
