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path: root/drivers/leds/trigger/ledtrig-tty.c
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Diffstat (limited to 'drivers/leds/trigger/ledtrig-tty.c')
-rw-r--r--drivers/leds/trigger/ledtrig-tty.c243
1 files changed, 206 insertions, 37 deletions
diff --git a/drivers/leds/trigger/ledtrig-tty.c b/drivers/leds/trigger/ledtrig-tty.c
index 3e69a7bde9..8cf1485e81 100644
--- a/drivers/leds/trigger/ledtrig-tty.c
+++ b/drivers/leds/trigger/ledtrig-tty.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
+#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/leds.h>
#include <linux/module.h>
@@ -12,15 +13,45 @@
struct ledtrig_tty_data {
struct led_classdev *led_cdev;
struct delayed_work dwork;
- struct mutex mutex;
+ struct completion sysfs;
const char *ttyname;
struct tty_struct *tty;
int rx, tx;
+ bool mode_rx;
+ bool mode_tx;
+ bool mode_cts;
+ bool mode_dsr;
+ bool mode_dcd;
+ bool mode_rng;
};
-static void ledtrig_tty_restart(struct ledtrig_tty_data *trigger_data)
+/* Indicates which state the LED should now display */
+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_DCD,
+ TRIGGER_TTY_RNG,
+};
+
+static int ledtrig_tty_wait_for_completion(struct device *dev)
{
- schedule_delayed_work(&trigger_data->dwork, 0);
+ struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev);
+ int ret;
+
+ ret = wait_for_completion_timeout(&trigger_data->sysfs,
+ msecs_to_jiffies(LEDTRIG_TTY_INTERVAL * 20));
+ if (ret == 0)
+ return -ETIMEDOUT;
+
+ return ret;
}
static ssize_t ttyname_show(struct device *dev,
@@ -28,14 +59,16 @@ static ssize_t ttyname_show(struct device *dev,
{
struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev);
ssize_t len = 0;
+ int completion;
- mutex_lock(&trigger_data->mutex);
+ reinit_completion(&trigger_data->sysfs);
+ completion = ledtrig_tty_wait_for_completion(dev);
+ if (completion < 0)
+ return completion;
if (trigger_data->ttyname)
len = sprintf(buf, "%s\n", trigger_data->ttyname);
- mutex_unlock(&trigger_data->mutex);
-
return len;
}
@@ -46,7 +79,7 @@ static ssize_t ttyname_store(struct device *dev,
struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev);
char *ttyname;
ssize_t ret = size;
- bool running;
+ int completion;
if (size > 0 && buf[size - 1] == '\n')
size -= 1;
@@ -59,9 +92,10 @@ static ssize_t ttyname_store(struct device *dev,
ttyname = NULL;
}
- mutex_lock(&trigger_data->mutex);
-
- running = trigger_data->ttyname != NULL;
+ reinit_completion(&trigger_data->sysfs);
+ completion = ledtrig_tty_wait_for_completion(dev);
+ if (completion < 0)
+ return completion;
kfree(trigger_data->ttyname);
tty_kref_put(trigger_data->tty);
@@ -69,29 +103,107 @@ static ssize_t ttyname_store(struct device *dev,
trigger_data->ttyname = ttyname;
- mutex_unlock(&trigger_data->mutex);
-
- if (ttyname && !running)
- ledtrig_tty_restart(trigger_data);
-
return ret;
}
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);
+ bool state;
+
+ switch (attr) {
+ case TRIGGER_TTY_RX:
+ state = trigger_data->mode_rx;
+ break;
+ case TRIGGER_TTY_TX:
+ state = trigger_data->mode_tx;
+ break;
+ case TRIGGER_TTY_CTS:
+ state = trigger_data->mode_cts;
+ break;
+ case TRIGGER_TTY_DSR:
+ state = trigger_data->mode_dsr;
+ break;
+ case TRIGGER_TTY_DCD:
+ state = trigger_data->mode_dcd;
+ break;
+ case TRIGGER_TTY_RNG:
+ state = trigger_data->mode_rng;
+ break;
+ }
+
+ return sysfs_emit(buf, "%u\n", state);
+}
+
+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);
+ bool state;
+ int ret;
+
+ ret = kstrtobool(buf, &state);
+ if (ret)
+ return ret;
+
+ switch (attr) {
+ case TRIGGER_TTY_RX:
+ trigger_data->mode_rx = state;
+ break;
+ case TRIGGER_TTY_TX:
+ trigger_data->mode_tx = state;
+ break;
+ case TRIGGER_TTY_CTS:
+ trigger_data->mode_cts = state;
+ break;
+ case TRIGGER_TTY_DSR:
+ trigger_data->mode_dsr = state;
+ break;
+ case TRIGGER_TTY_DCD:
+ trigger_data->mode_dcd = state;
+ break;
+ case TRIGGER_TTY_RNG:
+ trigger_data->mode_rng = state;
+ break;
+ }
+
+ return size;
+}
+
+#define DEFINE_TTY_TRIGGER(trigger_name, trigger) \
+ static ssize_t trigger_name##_show(struct device *dev, \
+ struct device_attribute *attr, char *buf) \
+ { \
+ return ledtrig_tty_attr_show(dev, buf, trigger); \
+ } \
+ static ssize_t trigger_name##_store(struct device *dev, \
+ struct device_attribute *attr, const char *buf, size_t size) \
+ { \
+ return ledtrig_tty_attr_store(dev, buf, size, trigger); \
+ } \
+ static DEVICE_ATTR_RW(trigger_name)
+
+DEFINE_TTY_TRIGGER(rx, TRIGGER_TTY_RX);
+DEFINE_TTY_TRIGGER(tx, TRIGGER_TTY_TX);
+DEFINE_TTY_TRIGGER(cts, TRIGGER_TTY_CTS);
+DEFINE_TTY_TRIGGER(dsr, TRIGGER_TTY_DSR);
+DEFINE_TTY_TRIGGER(dcd, TRIGGER_TTY_DCD);
+DEFINE_TTY_TRIGGER(rng, TRIGGER_TTY_RNG);
+
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 serial_icounter_struct icount;
+ enum led_trigger_tty_state state = TTY_LED_DISABLE;
+ unsigned long interval = LEDTRIG_TTY_INTERVAL;
+ bool invert = false;
+ int status;
int ret;
- mutex_lock(&trigger_data->mutex);
-
- if (!trigger_data->ttyname) {
- /* exit without rescheduling */
- mutex_unlock(&trigger_data->mutex);
- return;
- }
+ if (!trigger_data->ttyname)
+ goto out;
/* try to get the tty corresponding to $ttyname */
if (!trigger_data->tty) {
@@ -115,32 +227,83 @@ 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;
+ status = tty_get_tiocm(trigger_data->tty);
+ if (status > 0) {
+ if (trigger_data->mode_cts) {
+ if (status & TIOCM_CTS)
+ state = TTY_LED_ENABLE;
+ }
+
+ if (trigger_data->mode_dsr) {
+ if (status & TIOCM_DSR)
+ state = TTY_LED_ENABLE;
+ }
+
+ if (trigger_data->mode_dcd) {
+ if (status & TIOCM_CAR)
+ state = TTY_LED_ENABLE;
+ }
+
+ if (trigger_data->mode_rng) {
+ if (status & TIOCM_RNG)
+ state = TTY_LED_ENABLE;
+ }
}
- if (icount.rx != trigger_data->rx ||
- icount.tx != trigger_data->tx) {
- unsigned long interval = LEDTRIG_TTY_INTERVAL;
+ /*
+ * The evaluation of rx/tx must be done after the evaluation
+ * of TIOCM_*, because rx/tx has priority.
+ */
+ if (trigger_data->mode_rx || trigger_data->mode_tx) {
+ struct serial_icounter_struct icount;
- led_blink_set_oneshot(trigger_data->led_cdev, &interval,
- &interval, 0);
+ ret = tty_get_icount(trigger_data->tty, &icount);
+ if (ret)
+ goto out;
- trigger_data->rx = icount.rx;
- trigger_data->tx = icount.tx;
+ if (trigger_data->mode_tx && (icount.tx != trigger_data->tx)) {
+ trigger_data->tx = icount.tx;
+ invert = state == TTY_LED_ENABLE;
+ state = TTY_LED_BLINK;
+ }
+
+ if (trigger_data->mode_rx && (icount.rx != trigger_data->rx)) {
+ trigger_data->rx = icount.rx;
+ invert = state == TTY_LED_ENABLE;
+ state = TTY_LED_BLINK;
+ }
}
out:
- mutex_unlock(&trigger_data->mutex);
+ switch (state) {
+ case TTY_LED_BLINK:
+ led_blink_set_oneshot(trigger_data->led_cdev, &interval,
+ &interval, invert);
+ break;
+ case TTY_LED_ENABLE:
+ led_set_brightness(trigger_data->led_cdev,
+ trigger_data->led_cdev->blink_brightness);
+ break;
+ case TTY_LED_DISABLE:
+ fallthrough;
+ default:
+ led_set_brightness(trigger_data->led_cdev, LED_OFF);
+ break;
+ }
+
+ complete_all(&trigger_data->sysfs);
schedule_delayed_work(&trigger_data->dwork,
msecs_to_jiffies(LEDTRIG_TTY_INTERVAL * 2));
}
static struct attribute *ledtrig_tty_attrs[] = {
&dev_attr_ttyname.attr,
+ &dev_attr_rx.attr,
+ &dev_attr_tx.attr,
+ &dev_attr_cts.attr,
+ &dev_attr_dsr.attr,
+ &dev_attr_dcd.attr,
+ &dev_attr_rng.attr,
NULL
};
ATTRIBUTE_GROUPS(ledtrig_tty);
@@ -153,11 +316,17 @@ static int ledtrig_tty_activate(struct led_classdev *led_cdev)
if (!trigger_data)
return -ENOMEM;
+ /* Enable default rx/tx mode */
+ trigger_data->mode_rx = true;
+ trigger_data->mode_tx = true;
+
led_set_trigger_data(led_cdev, trigger_data);
INIT_DELAYED_WORK(&trigger_data->dwork, ledtrig_tty_work);
trigger_data->led_cdev = led_cdev;
- mutex_init(&trigger_data->mutex);
+ init_completion(&trigger_data->sysfs);
+
+ schedule_delayed_work(&trigger_data->dwork, 0);
return 0;
}