On Wed, 22 Feb 2023, Florian Eckert wrote:
> Add additional modes to trigger the selected LED.
> The following modes are supported:
>
> Tx/Rx: Flash LED on data transmission (default)
> CTS: DCE Ready to accept data from the DTE.
> DSR: DCE is ready to receive and send data.
> CAR: DCE is receiving a carrier from a remote DTE.
> RNG: DCE has detected an incoming ring signal.
>
> The mode can be changed for example with the following command:
> echo "CTS" > /sys/class/leds/<led>/mode
>
> This would turn on the LED, when the DTE(modem) signals the DCE that it
> is ready to accept data.
>
> Signed-off-by: Florian Eckert <fe@xxxxxxxxxx>
> ---
> .../ABI/testing/sysfs-class-led-trigger-tty | 17 ++
> drivers/leds/trigger/ledtrig-tty.c | 145 ++++++++++++++++--
> 2 files changed, 147 insertions(+), 15 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-class-led-trigger-tty b/Documentation/ABI/testing/sysfs-class-led-trigger-tty
> index 2bf6b24e781b..1c28e6c61d19 100644
> --- a/Documentation/ABI/testing/sysfs-class-led-trigger-tty
> +++ b/Documentation/ABI/testing/sysfs-class-led-trigger-tty
> @@ -4,3 +4,20 @@ KernelVersion: 5.10
> Contact: linux-leds@xxxxxxxxxxxxxxx
> Description:
> Specifies the tty device name of the triggering tty
> +
> +What: /sys/class/leds/<led>/mode
> +Date: January 2023
> +KernelVersion: 6.3
> +Description:
> + Specifies the operating to trigger the LED.
The operating ... ? "mode"?
> + The following operating modes are supported:
> +
> + * Tx/Rx: Flash LED on data transmission (default)
> + * CTS: DCE Ready to accept data from the DTE.
> + LED on if line is high.
> + * DSR: DCE is ready to receive and send data.
> + LED on if line is high.
> + * CAR: DCE has detected a carrier from a remote DTE.
> + LED on if line is high.
> + * RNG: DCE has detected an incoming ring signal.
> + LED on if line is high.
Seeing as this is unchanging, how about you mention it once globally?
> diff --git a/drivers/leds/trigger/ledtrig-tty.c b/drivers/leds/trigger/ledtrig-tty.c
> index f62db7e520b5..7c4c171c8745 100644
> --- a/drivers/leds/trigger/ledtrig-tty.c
> +++ b/drivers/leds/trigger/ledtrig-tty.c
> @@ -7,6 +7,15 @@
> #include <linux/tty.h>
> #include <uapi/linux/serial.h>
>
> +enum tty_led_mode {
> + TTY_LED_CNT,
What's CNT? Is it documented somewhere else? Ah, I see below that this
is Tx/Rx. Odd name, what does it mean? Defines and Enums should be
self documenting IMHO.
> + TTY_LED_CTS,
> + TTY_LED_DSR,
> + TTY_LED_CAR,
> + TTY_LED_RNG,
> + __TTY_LED_LAST = TTY_LED_RNG
Do you have to prepend with _'s?
> +};
> +
> struct ledtrig_tty_data {
> struct led_classdev *led_cdev;
> struct delayed_work dwork;
> @@ -14,6 +23,15 @@ struct ledtrig_tty_data {
> const char *ttyname;
> struct tty_struct *tty;
> int rx, tx;
> + enum tty_led_mode mode;
> +};
> +
> +static const char * const mode[] = {
> + [TTY_LED_CNT] = "Tx/Rx", // Trasmit Data / Receive Data
C++ style comments?
> + [TTY_LED_CTS] = "CTS", // CTS Clear To Send
> + [TTY_LED_DSR] = "DSR", // DSR Data Set Ready
> + [TTY_LED_CAR] = "CAR", // CAR Data Carrier Detect (DCD)
> + [TTY_LED_RNG] = "RNG", // RNG Ring Indicator (RI)
> };
>
> static void ledtrig_tty_restart(struct ledtrig_tty_data *trigger_data)
> @@ -21,6 +39,70 @@ static void ledtrig_tty_restart(struct ledtrig_tty_data *trigger_data)
> schedule_delayed_work(&trigger_data->dwork, 0);
> }
>
> +static ssize_t ledtrig_tty_mode_show(char *buf, enum tty_led_mode tty_mode)
> +{
> + int len = 0;
> + int i;
> +
> + for (i = 0; i <= __TTY_LED_LAST; i++) {
> + bool hit = tty_mode == i;
> + bool last = i == __TTY_LED_LAST;
> +
> + len += sysfs_emit_at(buf, len, "%s%s%s%s",
> + hit ? "[" : "",
> + mode[i],
> + hit ? "]" : "",
> + last ? "" : " ");
> + }
> +
> + len += sysfs_emit_at(buf, len, "\n");
> +
> + return len;
> +}
> +
> +static ssize_t tty_led_mode_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
This may be a personal preference, but I'd rather see alignment with the '('.
> +{
> + struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev);
> + enum tty_led_mode tty_mode;
> +
> + mutex_lock(&trigger_data->mutex);
> + tty_mode = trigger_data->mode;
> + mutex_unlock(&trigger_data->mutex);
> +
> + return ledtrig_tty_mode_show(buf, tty_mode);
> +}
> +
> +static ssize_t tty_led_mode_store(struct device *dev,
> + struct device_attribute *attr, const char *buf,
> + size_t size)
> +{
> + struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev);
> + ssize_t ret = size;
> + enum tty_led_mode tty_mode = __TTY_LED_LAST;
Nit: Can you reverse these 2 lines to make my OCD happy please?
> + int i;
> +
> + /* Check for new line in string*/
' ' before the '*'.
> + if (size > 0 && buf[size - 1] == '\n')
> + size -= 1;
> +
> + for (i = 0; i <= __TTY_LED_LAST; i++)
> + if (strncmp(buf, mode[i], size) == 0) {
> + tty_mode = i;
> + break;
> + }
> +
> + if (i > __TTY_LED_LAST)
> + return -EINVAL;
> +
> + mutex_lock(&trigger_data->mutex);
> + trigger_data->mode = tty_mode;
> + mutex_unlock(&trigger_data->mutex);
> +
> + return ret;
> +}
> +static DEVICE_ATTR_RW(tty_led_mode);
> +
> static ssize_t ttyname_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> @@ -76,6 +158,18 @@ static ssize_t ttyname_store(struct device *dev,
> }
> static DEVICE_ATTR_RW(ttyname);
>
> +static void ledtrig_tty_flags(struct ledtrig_tty_data *trigger_data,
> + unsigned int flag)
This can be on a single line. Please use 100-chars throughout.
> +{
> + unsigned int status;
> +
> + status = tty_get_mget(trigger_data->tty);
> + if (status & flag)
> + led_set_brightness_sync(trigger_data->led_cdev, LED_ON);
> + else
> + led_set_brightness_sync(trigger_data->led_cdev, LED_OFF);
> +}
> +
> static void ledtrig_tty_work(struct work_struct *work)
> {
> struct ledtrig_tty_data *trigger_data =
> @@ -113,21 +207,38 @@ static void ledtrig_tty_work(struct work_struct *work)
> trigger_data->tty = tty;
> }
>
> - ret = tty_get_icount(trigger_data->tty, &icount);
> - if (ret) {
> - dev_info(trigger_data->tty->dev, "Failed to get icount, stopped polling\n");
> - mutex_unlock(&trigger_data->mutex);
> - return;
> - }
> -
> - if (icount.rx != trigger_data->rx ||
> - icount.tx != trigger_data->tx) {
> - led_set_brightness_sync(trigger_data->led_cdev, LED_ON);
> -
> - trigger_data->rx = icount.rx;
> - trigger_data->tx = icount.tx;
> - } else {
> - led_set_brightness_sync(trigger_data->led_cdev, LED_OFF);
> + switch (trigger_data->mode) {
> + case TTY_LED_CTS:
> + ledtrig_tty_flags(trigger_data, TIOCM_CTS);
> + break;
> + case TTY_LED_DSR:
> + ledtrig_tty_flags(trigger_data, TIOCM_DSR);
> + break;
> + case TTY_LED_CAR:
> + ledtrig_tty_flags(trigger_data, TIOCM_CAR);
> + break;
> + case TTY_LED_RNG:
> + ledtrig_tty_flags(trigger_data, TIOCM_RNG);
> + break;
> + case TTY_LED_CNT:
I believe this requires a 'fall-through' statement.
Documentation/process/deprecated.rst
> + default:
> + ret = tty_get_icount(trigger_data->tty, &icount);
> + if (ret) {
> + dev_info(trigger_data->tty->dev, "Failed to get icount, stopped polling\n");
> + mutex_unlock(&trigger_data->mutex);
> + return;
> + }
> +
> + if (icount.rx != trigger_data->rx ||
> + icount.tx != trigger_data->tx) {
One line, etc.
> + led_set_brightness_sync(trigger_data->led_cdev, LED_ON);
> +
> + trigger_data->rx = icount.rx;
> + trigger_data->tx = icount.tx;
> + } else {
> + led_set_brightness_sync(trigger_data->led_cdev, LED_OFF);
> + }
> + break;
> }
>
> out:
> @@ -137,6 +248,7 @@ static void ledtrig_tty_work(struct work_struct *work)
>
> static struct attribute *ledtrig_tty_attrs[] = {
> &dev_attr_ttyname.attr,
> + &dev_attr_tty_led_mode.attr,
> NULL
> };
> ATTRIBUTE_GROUPS(ledtrig_tty);
> @@ -149,6 +261,9 @@ static int ledtrig_tty_activate(struct led_classdev *led_cdev)
> if (!trigger_data)
> return -ENOMEM;
>
> + /* set default mode */
Nit: "Set"
> + trigger_data->mode = TTY_LED_CNT;
> +
> led_set_trigger_data(led_cdev, trigger_data);
>
> INIT_DELAYED_WORK(&trigger_data->dwork, ledtrig_tty_work);
> --
> 2.30.2
>
--
Lee Jones [李琼斯]
