Hello,
here commes v3 of this series to add additional tty_led_modes.
v3:
Changes compared to the v2 patchset with
[email protected] are.
Addressed review comments by Greg K-H are:
tty.h:
- Fix first comment line and remark -%ENOTTY for the new function
'tty_get_mget' to make a proper kernel doc.
- Add the return value -%ENOTTY again, I thought it was no longer needed.
v2:
Changes compared to the initial patchset with
[email protected] are.
Addressed review comments by Jiri Slaby are:
tty.h:
- Fix compilation error because of wrong rebaseing
- Remove empty lines
- Use new 'tty_get_mget' in 'tty_tiocmget'
ledtrg-tty.c:
- Update commit description
- Use enum for tty_led_mod in struct ledtrig_tty_date
- Rename sysfs file from 'mode' to 'tty_led_mode'
- Change tty_led_mode show function to use loop instead of switch/case
- Change tty_led_mode store function to use loop instead of switch/case
- Check return value of function tty_get_mget
Florian Eckert (2):
tty: new helper function tty_get_mget
trigger: ledtrig-tty: add additional modes
.../ABI/testing/sysfs-class-led-trigger-tty | 16 ++
drivers/leds/trigger/ledtrig-tty.c | 146 ++++++++++++++++--
drivers/tty/tty_io.c | 28 +++-
include/linux/tty.h | 1 +
4 files changed, 170 insertions(+), 21 deletions(-)
--
2.30.2
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 <[email protected]>
---
drivers/tty/tty_io.c | 28 ++++++++++++++++++++++------
include/linux/tty.h | 1 +
2 files changed, 23 insertions(+), 6 deletions(-)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 3149114bf130..a068b03a0828 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2493,6 +2493,24 @@ 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
@@ -2505,14 +2523,12 @@ static int send_break(struct tty_struct *tty, unsigned int duration)
*/
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
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 <[email protected]>
---
.../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: [email protected]
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
On 20. 02. 23, 10:37, 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 <[email protected]>
> --- 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,
I would do:
__TTY_LED_LAST = TTY_LED_RNG;
instead of:
> + __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;
Both the decl and assignment can be on a single line.
> + 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, " ");
And all this could be then:
for (i = 0; i <= __TTY_LED_LAST; i++) {
bool hit = i == tty_mode;
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_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;
Ah, you use __TTY_LED_MAX as an extra value. It doesn't look nice. So
now, what about:
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;
?
thanks,
--
js
suse labs