diff mbox series

[2/2] trigger: ledtrig-tty: add new line mode to triggers

Message ID 20230926093607.59536-3-fe@dev.tdt.de
State Superseded
Headers show
Series ledtrig-tty: add new state evaluation | expand

Commit Message

Florian Eckert Sept. 26, 2023, 9:36 a.m. UTC 
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 (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 (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 (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
  (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).

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@dev.tdt.de>
---
 .../ABI/testing/sysfs-class-led-trigger-tty   |  54 ++++
 drivers/leds/trigger/ledtrig-tty.c            | 272 +++++++++++++++++-
 2 files changed, 315 insertions(+), 11 deletions(-)

Comments

kernel test robot Sept. 26, 2023, 8:33 p.m. UTC | #1 
Hi Florian,

kernel test robot noticed the following build errors:

[auto build test ERROR on tty/tty-testing]
[also build test ERROR on tty/tty-next tty/tty-linus staging/staging-testing staging/staging-next staging/staging-linus linus/master v6.6-rc3 next-20230926]
[cannot apply to pavel-leds/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Florian-Eckert/tty-add-new-helper-function-tty_get_mget/20230926-180154
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing
patch link:    https://lore.kernel.org/r/20230926093607.59536-3-fe%40dev.tdt.de
patch subject: [PATCH 2/2] trigger: ledtrig-tty: add new line mode to triggers
config: x86_64-randconfig-161-20230927 (https://download.01.org/0day-ci/archive/20230927/202309270440.IJB24Xap-lkp@intel.com/config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230927/202309270440.IJB24Xap-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202309270440.IJB24Xap-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/leds/trigger/ledtrig-tty.c: In function 'ledtrig_tty_work':
>> drivers/leds/trigger/ledtrig-tty.c:362:3: error: a label can only be part of a statement and a declaration is not a statement
      unsigned long interval = LEDTRIG_TTY_INTERVAL;
      ^~~~~~~~


vim +362 drivers/leds/trigger/ledtrig-tty.c

   270	
   271	static void ledtrig_tty_work(struct work_struct *work)
   272	{
   273		struct ledtrig_tty_data *trigger_data =
   274			container_of(work, struct ledtrig_tty_data, dwork.work);
   275		struct led_classdev *led_cdev = trigger_data->led_cdev;
   276		struct serial_icounter_struct icount;
   277		enum tty_led_state state;
   278		int ret;
   279	
   280		state = TTY_LED_DISABLE;
   281		mutex_lock(&trigger_data->mutex);
   282	
   283		if (!trigger_data->ttyname) {
   284			/* exit without rescheduling */
   285			mutex_unlock(&trigger_data->mutex);
   286			return;
   287		}
   288	
   289		/* try to get the tty corresponding to $ttyname */
   290		if (!trigger_data->tty) {
   291			dev_t devno;
   292			struct tty_struct *tty;
   293			int ret;
   294	
   295			ret = tty_dev_name_to_number(trigger_data->ttyname, &devno);
   296			if (ret < 0)
   297				/*
   298				 * A device with this name might appear later, so keep
   299				 * retrying.
   300				 */
   301				goto out;
   302	
   303			tty = tty_kopen_shared(devno);
   304			if (IS_ERR(tty) || !tty)
   305				/* What to do? retry or abort */
   306				goto out;
   307	
   308			trigger_data->tty = tty;
   309		}
   310	
   311		if (test_bit(LEDTRIG_TTY_MODE_CTS, &trigger_data->mode)) {
   312			ret = ledtrig_tty_flag(trigger_data, TIOCM_CTS);
   313			if (ret)
   314				state = TTY_LED_ENABLE;
   315		}
   316	
   317		if (test_bit(LEDTRIG_TTY_MODE_DSR, &trigger_data->mode)) {
   318			ret = ledtrig_tty_flag(trigger_data, TIOCM_DSR);
   319			if (ret)
   320				state = TTY_LED_ENABLE;
   321		}
   322	
   323		if (test_bit(LEDTRIG_TTY_MODE_CAR, &trigger_data->mode)) {
   324			ret = ledtrig_tty_flag(trigger_data, TIOCM_CAR);
   325			if (ret)
   326				state = TTY_LED_ENABLE;
   327		}
   328	
   329		if (test_bit(LEDTRIG_TTY_MODE_RNG, &trigger_data->mode)) {
   330			ret = ledtrig_tty_flag(trigger_data, TIOCM_RNG);
   331			if (ret)
   332				state = TTY_LED_ENABLE;
   333		}
   334	
   335		/* The rx/tx handling must come after the evaluation of TIOCM_*,
   336		 * since the display for rx/tx has priority
   337		 */
   338		if (test_bit(LEDTRIG_TTY_MODE_TX, &trigger_data->mode) ||
   339		    test_bit(LEDTRIG_TTY_MODE_RX, &trigger_data->mode)) {
   340			ret = tty_get_icount(trigger_data->tty, &icount);
   341			if (ret) {
   342				dev_info(trigger_data->tty->dev, "Failed to get icount, stopped polling\n");
   343				mutex_unlock(&trigger_data->mutex);
   344				return;
   345			}
   346	
   347			if (test_bit(LEDTRIG_TTY_MODE_TX, &trigger_data->mode) &&
   348			    (icount.tx != trigger_data->tx)) {
   349				trigger_data->tx = icount.tx;
   350				state = TTY_LED_BLINK;
   351			}
   352	
   353			if (test_bit(LEDTRIG_TTY_MODE_RX, &trigger_data->mode) &&
   354			    (icount.rx != trigger_data->rx)) {
   355				trigger_data->rx = icount.rx;
   356				state = TTY_LED_BLINK;
   357			}
   358		}
   359	
   360		switch (state) {
   361		case TTY_LED_BLINK:
 > 362			unsigned long interval = LEDTRIG_TTY_INTERVAL;
   363			led_blink_set_oneshot(trigger_data->led_cdev, &interval,
   364					      &interval, 0);
   365			break;
   366		case TTY_LED_ENABLE:
   367			led_set_brightness(led_cdev, led_cdev->blink_brightness);
   368			break;
   369		case TTY_LED_DISABLE:
   370			fallthrough;
   371		default:
   372			led_set_brightness(led_cdev, 0);
   373			break;
   374		}
   375	
   376	out:
   377		mutex_unlock(&trigger_data->mutex);
   378		schedule_delayed_work(&trigger_data->dwork,
   379				      msecs_to_jiffies(LEDTRIG_TTY_INTERVAL * 2));
   380	}
   381
diff mbox series

Patch

diff --git a/Documentation/ABI/testing/sysfs-class-led-trigger-tty b/Documentation/ABI/testing/sysfs-class-led-trigger-tty
index 2bf6b24e781b..14c38a2370ea 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@vger.kernel.org
 Description:
 		Specifies the tty device name of the triggering tty
+
+What:		/sys/class/leds/<led>/rx
+Date:		September 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:		September 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:		September 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:		September 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:		September 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:		September 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..0ea6d2a2599d 100644
--- a/drivers/leds/trigger/ledtrig-tty.c
+++ b/drivers/leds/trigger/ledtrig-tty.c
@@ -16,6 +16,28 @@  struct ledtrig_tty_data {
 	const char *ttyname;
 	struct tty_struct *tty;
 	int rx, tx;
+	unsigned long mode;
+#define LEDTRIG_TTY_MODE_TX	0
+#define LEDTRIG_TTY_MODE_RX	1
+#define LEDTRIG_TTY_MODE_CTS	2
+#define LEDTRIG_TTY_MODE_DSR	3
+#define LEDTRIG_TTY_MODE_CAR	4
+#define LEDTRIG_TTY_MODE_RNG	5
+};
+
+enum tty_led_state {
+	TTY_LED_BLINK,
+	TTY_LED_ENABLE,
+	TTY_LED_DISABLE,
+};
+
+enum ledtrig_tty_attr {
+	LEDTRIG_TTY_ATTR_TX,
+	LEDTRIG_TTY_ATTR_RX,
+	LEDTRIG_TTY_ATTR_CTS,
+	LEDTRIG_TTY_ATTR_DSR,
+	LEDTRIG_TTY_ATTR_CAR,
+	LEDTRIG_TTY_ATTR_RNG,
 };
 
 static void ledtrig_tty_restart(struct ledtrig_tty_data *trigger_data)
@@ -78,13 +100,184 @@  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 ledtrig_tty_attr attr)
+{
+	struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev);
+	int bit;
+
+	switch (attr) {
+	case LEDTRIG_TTY_ATTR_TX:
+		bit = LEDTRIG_TTY_MODE_TX;
+		break;
+	case LEDTRIG_TTY_ATTR_RX:
+		bit = LEDTRIG_TTY_MODE_RX;
+		break;
+	case LEDTRIG_TTY_ATTR_CTS:
+		bit = LEDTRIG_TTY_MODE_CTS;
+		break;
+	case LEDTRIG_TTY_ATTR_DSR:
+		bit = LEDTRIG_TTY_MODE_DSR;
+		break;
+	case LEDTRIG_TTY_ATTR_CAR:
+		bit = LEDTRIG_TTY_MODE_CAR;
+		break;
+	case LEDTRIG_TTY_ATTR_RNG:
+		bit = LEDTRIG_TTY_MODE_RNG;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
+}
+
+static ssize_t ledtrig_tty_attr_store(struct device *dev, const char *buf,
+	size_t size, enum ledtrig_tty_attr 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 LEDTRIG_TTY_ATTR_TX:
+		bit = LEDTRIG_TTY_MODE_TX;
+		break;
+	case LEDTRIG_TTY_ATTR_RX:
+		bit = LEDTRIG_TTY_MODE_RX;
+		break;
+	case LEDTRIG_TTY_ATTR_CTS:
+		bit = LEDTRIG_TTY_MODE_CTS;
+		break;
+	case LEDTRIG_TTY_ATTR_DSR:
+		bit = LEDTRIG_TTY_MODE_DSR;
+		break;
+	case LEDTRIG_TTY_ATTR_CAR:
+		bit = LEDTRIG_TTY_MODE_CAR;
+		break;
+	case LEDTRIG_TTY_ATTR_RNG:
+		bit = LEDTRIG_TTY_MODE_RNG;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (state)
+		set_bit(bit, &trigger_data->mode);
+	else
+		clear_bit(bit, &trigger_data->mode);
+
+	return size;
+}
+
+static ssize_t tx_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	return ledtrig_tty_attr_show(dev, buf, LEDTRIG_TTY_ATTR_TX);
+}
+
+static ssize_t tx_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t size)
+{
+	return ledtrig_tty_attr_store(dev, buf, size, LEDTRIG_TTY_ATTR_TX);
+}
+static DEVICE_ATTR_RW(tx);
+
+static ssize_t rx_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	return ledtrig_tty_attr_show(dev, buf, LEDTRIG_TTY_ATTR_RX);
+}
+
+static ssize_t rx_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t size)
+{
+	return ledtrig_tty_attr_store(dev, buf, size, LEDTRIG_TTY_ATTR_RX);
+}
+static DEVICE_ATTR_RW(rx);
+
+static ssize_t line_cts_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	return ledtrig_tty_attr_show(dev, buf, LEDTRIG_TTY_ATTR_CTS);
+}
+
+static ssize_t line_cts_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t size)
+{
+	return ledtrig_tty_attr_store(dev, buf, size, LEDTRIG_TTY_ATTR_CTS);
+}
+static DEVICE_ATTR_RW(line_cts);
+
+static ssize_t line_dsr_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	return ledtrig_tty_attr_show(dev, buf, LEDTRIG_TTY_ATTR_DSR);
+}
+
+static ssize_t line_dsr_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t size)
+{
+	return ledtrig_tty_attr_store(dev, buf, size, LEDTRIG_TTY_ATTR_DSR);
+}
+static DEVICE_ATTR_RW(line_dsr);
+
+static ssize_t line_car_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	return ledtrig_tty_attr_show(dev, buf, LEDTRIG_TTY_ATTR_CAR);
+}
+
+static ssize_t line_car_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t size)
+{
+	return ledtrig_tty_attr_store(dev, buf, size, LEDTRIG_TTY_ATTR_CAR);
+}
+static DEVICE_ATTR_RW(line_car);
+
+static ssize_t line_rng_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	return ledtrig_tty_attr_show(dev, buf, LEDTRIG_TTY_ATTR_RNG);
+}
+
+static ssize_t line_rng_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t size)
+{
+	return ledtrig_tty_attr_store(dev, buf, size, LEDTRIG_TTY_ATTR_RNG);
+}
+static DEVICE_ATTR_RW(line_rng);
+
+
+static int ledtrig_tty_flag(struct ledtrig_tty_data *trigger_data, unsigned int flag)
+{
+	unsigned int status;
+	int ret;
+
+	status = tty_get_mget(trigger_data->tty);
+	if (status & flag)
+		ret = 1;
+	else
+		ret = 0;
+
+	return ret;
+}
+
 static void ledtrig_tty_work(struct work_struct *work)
 {
 	struct ledtrig_tty_data *trigger_data =
 		container_of(work, struct ledtrig_tty_data, dwork.work);
+	struct led_classdev *led_cdev = trigger_data->led_cdev;
 	struct serial_icounter_struct icount;
+	enum tty_led_state state;
 	int ret;
 
+	state = TTY_LED_DISABLE;
 	mutex_lock(&trigger_data->mutex);
 
 	if (!trigger_data->ttyname) {
@@ -115,22 +308,69 @@  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 (test_bit(LEDTRIG_TTY_MODE_CTS, &trigger_data->mode)) {
+		ret = ledtrig_tty_flag(trigger_data, TIOCM_CTS);
+		if (ret)
+			state = TTY_LED_ENABLE;
 	}
 
-	if (icount.rx != trigger_data->rx ||
-	    icount.tx != trigger_data->tx) {
-		unsigned long interval = LEDTRIG_TTY_INTERVAL;
+	if (test_bit(LEDTRIG_TTY_MODE_DSR, &trigger_data->mode)) {
+		ret = ledtrig_tty_flag(trigger_data, TIOCM_DSR);
+		if (ret)
+			state = TTY_LED_ENABLE;
+	}
 
+	if (test_bit(LEDTRIG_TTY_MODE_CAR, &trigger_data->mode)) {
+		ret = ledtrig_tty_flag(trigger_data, TIOCM_CAR);
+		if (ret)
+			state = TTY_LED_ENABLE;
+	}
+
+	if (test_bit(LEDTRIG_TTY_MODE_RNG, &trigger_data->mode)) {
+		ret = ledtrig_tty_flag(trigger_data, TIOCM_RNG);
+		if (ret)
+			state = TTY_LED_ENABLE;
+	}
+
+	/* The rx/tx handling must come after the evaluation of TIOCM_*,
+	 * since the display for rx/tx has priority
+	 */
+	if (test_bit(LEDTRIG_TTY_MODE_TX, &trigger_data->mode) ||
+	    test_bit(LEDTRIG_TTY_MODE_RX, &trigger_data->mode)) {
+		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 (test_bit(LEDTRIG_TTY_MODE_TX, &trigger_data->mode) &&
+		    (icount.tx != trigger_data->tx)) {
+			trigger_data->tx = icount.tx;
+			state = TTY_LED_BLINK;
+		}
+
+		if (test_bit(LEDTRIG_TTY_MODE_RX, &trigger_data->mode) &&
+		    (icount.rx != trigger_data->rx)) {
+			trigger_data->rx = icount.rx;
+			state = TTY_LED_BLINK;
+		}
+	}
+
+	switch (state) {
+	case TTY_LED_BLINK:
+		unsigned long interval = LEDTRIG_TTY_INTERVAL;
 		led_blink_set_oneshot(trigger_data->led_cdev, &interval,
 				      &interval, 0);
-
-		trigger_data->rx = icount.rx;
-		trigger_data->tx = icount.tx;
+		break;
+	case TTY_LED_ENABLE:
+		led_set_brightness(led_cdev, led_cdev->blink_brightness);
+		break;
+	case TTY_LED_DISABLE:
+		fallthrough;
+	default:
+		led_set_brightness(led_cdev, 0);
+		break;
 	}
 
 out:
@@ -141,6 +381,12 @@  static void ledtrig_tty_work(struct work_struct *work)
 
 static struct attribute *ledtrig_tty_attrs[] = {
 	&dev_attr_ttyname.attr,
+	&dev_attr_rx.attr,
+	&dev_attr_tx.attr,
+	&dev_attr_line_cts.attr,
+	&dev_attr_line_dsr.attr,
+	&dev_attr_line_car.attr,
+	&dev_attr_line_rng.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(ledtrig_tty);
@@ -153,6 +399,10 @@  static int ledtrig_tty_activate(struct led_classdev *led_cdev)
 	if (!trigger_data)
 		return -ENOMEM;
 
+	/* Enable default rx/tx LED blink */
+	set_bit(LEDTRIG_TTY_MODE_TX, &trigger_data->mode);
+	set_bit(LEDTRIG_TTY_MODE_RX, &trigger_data->mode);
+
 	led_set_trigger_data(led_cdev, trigger_data);
 
 	INIT_DELAYED_WORK(&trigger_data->dwork, ledtrig_tty_work);