* [PATCH v2 1/2] tty: new helper function tty_get_mget
2023-02-17 9:44 [PATCH v2 0/2] leds: ledtrig-tty: add tty_led_mode xtension Florian Eckert
@ 2023-02-17 9:44 ` Florian Eckert
2023-02-17 9:49 ` Greg KH
2023-02-17 9:44 ` [PATCH v2 2/2] trigger: ledtrig-tty: add additional modes Florian Eckert
1 sibling, 1 reply; 4+ messages in thread
From: Florian Eckert @ 2023-02-17 9:44 UTC (permalink / raw)
To: u.kleine-koenig, gregkh, jirislaby, pavel, lee
Cc: linux-kernel, linux-leds, Eckert.Florian
For a given struct tty_struct, this provides the appropriate tty line
state flags needed to add more modes to the ledtrig-tty trigger.
The new function is then used to get via tty_tiocmget() the different tty
line states.
Signed-off-by: Florian Eckert <fe@dev.tdt.de>
---
drivers/tty/tty_io.c | 30 +++++++++++++++++++++++-------
include/linux/tty.h | 1 +
2 files changed, 24 insertions(+), 7 deletions(-)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 3149114bf130..f049ab8b3362 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2493,26 +2493,42 @@ static int send_break(struct tty_struct *tty, unsigned int duration)
return retval;
}
+/*
+ * tty_get_mget - get modem status
+ * @tty: tty device
+ *
+ * Obtain the modem status bits from the tty driver if the feature
+ * is supported. Return -ENOTTY if it is not available.
+ */
+int tty_get_mget(struct tty_struct *tty)
+{
+ int retval = -ENOTTY;
+
+ if (tty->ops->tiocmget)
+ retval = tty->ops->tiocmget(tty);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(tty_get_mget);
+
/**
* tty_tiocmget - get modem status
* @tty: tty device
* @p: pointer to result
*
* Obtain the modem status bits from the tty driver if the feature is
- * supported. Return -%ENOTTY if it is not available.
+ * supported.
*
* Locking: none (up to the driver)
*/
static int tty_tiocmget(struct tty_struct *tty, int __user *p)
{
- int retval = -ENOTTY;
+ int retval;
- if (tty->ops->tiocmget) {
- retval = tty->ops->tiocmget(tty);
+ retval = tty_get_mget(tty);
+ if (retval >= 0)
+ retval = put_user(retval, p);
- if (retval >= 0)
- retval = put_user(retval, p);
- }
return retval;
}
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 730c3301d710..825186c0fec1 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -421,6 +421,7 @@ int tty_unthrottle_safe(struct tty_struct *tty);
int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
int tty_get_icount(struct tty_struct *tty,
struct serial_icounter_struct *icount);
+int tty_get_mget(struct tty_struct *tty);
int is_current_pgrp_orphaned(void);
void tty_hangup(struct tty_struct *tty);
void tty_vhangup(struct tty_struct *tty);
--
2.30.2
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v2 2/2] trigger: ledtrig-tty: add additional modes
2023-02-17 9:44 [PATCH v2 0/2] leds: ledtrig-tty: add tty_led_mode xtension Florian Eckert
2023-02-17 9:44 ` [PATCH v2 1/2] tty: new helper function tty_get_mget Florian Eckert
@ 2023-02-17 9:44 ` Florian Eckert
1 sibling, 0 replies; 4+ messages in thread
From: Florian Eckert @ 2023-02-17 9:44 UTC (permalink / raw)
To: u.kleine-koenig, gregkh, jirislaby, pavel, lee
Cc: linux-kernel, linux-leds, Eckert.Florian
Until now, the LED is flashed when data is transmitted. With a
legacy serial interface there are additional input signal lines.
CTS: Clear To Send -> DCE is ready to accept data from the DTE
DSR: Data Set Ready -> DCE is ready to receive and send data.
CAR: Data Carrier Detect -> DCE is receiving a carrier from a remote DCE.
RNG: Ring Indicator -> DCE has detected an incoming ring on the line.
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>/tty_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@dev.tdt.de>
---
.../ABI/testing/sysfs-class-led-trigger-tty | 16 ++
drivers/leds/trigger/ledtrig-tty.c | 146 ++++++++++++++++--
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..31d62a5ae095 100644
--- a/Documentation/ABI/testing/sysfs-class-led-trigger-tty
+++ b/Documentation/ABI/testing/sysfs-class-led-trigger-tty
@@ -4,3 +4,19 @@ KernelVersion: 5.10
Contact: linux-leds@vger.kernel.org
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 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 is receiving 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.
diff --git a/drivers/leds/trigger/ledtrig-tty.c b/drivers/leds/trigger/ledtrig-tty.c
index f62db7e520b5..09d1be7b8ffb 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,
+ TTY_LED_CTS,
+ TTY_LED_DSR,
+ TTY_LED_CAR,
+ TTY_LED_RNG,
+ __TTY_LED_MAX
+};
+
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
+ [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 +39,71 @@ 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_MAX; i++) {
+ bool hit;
+
+ hit = tty_mode == i;
+ len += sysfs_emit_at(buf, len, "%s%s%s",
+ hit ? "[" : "",
+ mode[i],
+ hit ? "]" : "");
+
+ if (i < __TTY_LED_MAX - 1)
+ len += sysfs_emit_at(buf, len, " ");
+ }
+
+ 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)
+{
+ 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_MAX;
+ int i;
+
+ /* Check for new line in string*/
+ if (size > 0 && buf[size - 1] == '\n')
+ size -= 1;
+
+ for (i = 0; i < __TTY_LED_MAX; i++) {
+ if (strncmp(buf, mode[i], size) == 0)
+ tty_mode = i;
+ }
+
+ if (tty_mode == __TTY_LED_MAX)
+ 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 +159,18 @@ 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)
+{
+ 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 +208,38 @@ 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:
+ 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) {
+ 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 +249,7 @@ 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 +262,9 @@ static int ledtrig_tty_activate(struct led_classdev *led_cdev)
if (!trigger_data)
return -ENOMEM;
+ /* set default mode */
+ 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
^ permalink raw reply related [flat|nested] 4+ messages in thread