[pulseaudio-discuss] [PATCH 2/2] alsa: load jack detection module

[Jorge Eduardo Candelaria]

From: Margarita Olaya Cabrera <magi at slimlogic.co.uk>

This patch adds support for udev detection of sound card jack event devices.

When a new card is detected, the code now also checks for the presence of any
associated input device via udev, and report the device to module-alsa-card
via its jack_id parameter.

Jack support development was kindly sponsored by Wolfson Microelectronics PLC

Signed-off-by: Margarita Olaya Cabrera <magi at slimlogic.co.uk>
Signed-off-by: Jorge Eduardo Candelaria <jedu at slimlogic.co.uk>
---
src/modules/module-udev-detect.c |   68 ++++++++++++++++++++++++++++++++++---
1 files changed, 62 insertions(+), 6 deletions(-)

diff --git a/src/modules/module-udev-detect.c b/src/modules/module-udev-detect.c
index 63ad195..4321b32 100644
--- a/src/modules/module-udev-detect.c
+++ b/src/modules/module-udev-detect.c
@@ -71,6 +71,8 @@ struct userdata {

    int inotify_fd;
    pa_io_event *inotify_io;
+
+    char *card_name;
};

static const char* const valid_modargs[] = {
@@ -163,6 +165,21 @@ static pa_bool_t pcm_is_modem(const char *card_idx, const char *pcm) {
    return is_modem;
}

+static pa_bool_t input_node_belongs_to_device(
+        struct device *d,
+        const char *node) {
+
+    char *cd;
+    pa_bool_t b;
+
+    cd = pa_sprintf_malloc("/sys%s", d->path);
+
+    b = pa_startswith(node, cd);
+    pa_xfree(cd);
+
+    return b;
+}
+
static pa_bool_t is_card_busy(const char *id) {
    char *card_path = NULL, *pcm_path = NULL, *sub_status = NULL;
    DIR *card_dir = NULL, *pcm_dir = NULL;
@@ -352,11 +369,26 @@ static void verify_access(struct userdata *u, struct device *d) {
    }
}

+static const char *jack_get_input_id(const char *path) {
+    int i;
+
+    for( i = 0; i < strlen(path); i++) {
+        if (pa_startswith(path + i, "/input"))
+            return path + i + 6;
+    }
+
+    return NULL;
+}
+
static void card_changed(struct userdata *u, struct udev_device *dev) {
    struct device *d;
+    struct udev_enumerate *enumerate;
+    struct udev_list_entry *item, *first;
    const char *path;
    const char *t;
    char *n;
+    char *jack_path;
+    char *jack_input;

    pa_assert(u);
    pa_assert(dev);
@@ -383,6 +415,28 @@ static void card_changed(struct userdata *u, struct udev_device *dev) {

    n = pa_namereg_make_valid_name(t);
    d->card_name = pa_sprintf_malloc("alsa_card.%s", n);
+
+    if (!(enumerate = udev_enumerate_new(u->udev)))
+        pa_log("Failed to initialize udev enumerator");
+    else {
+        if (!udev_enumerate_add_match_subsystem(enumerate, "input"))
+            pa_log_debug("Failed to match to subsystem input");
+
+        if (udev_enumerate_scan_devices(enumerate))
+            pa_log_debug("Failed to scan for devices");
+
+        first = udev_enumerate_get_list_entry(enumerate);
+        udev_list_entry_foreach(item, first) {
+            jack_path = udev_list_entry_get_name(item);
+            if (input_node_belongs_to_device(d, jack_path)) {
+                jack_input = pa_xstrdup(jack_get_input_id(jack_path));
+                pa_log_debug("jack is %s\n", jack_input);
+                break;
+            }
+        }
+        udev_enumerate_unref(enumerate);
+    }
+
    d->args = pa_sprintf_malloc("device_id=\"%s\" "
                                "name=\"%s\" "
                                "card_name=\"%s\" "
@@ -390,15 +444,19 @@ static void card_changed(struct userdata *u, struct udev_device *dev) {
                                "tsched=%s "
                                "ignore_dB=%s "
                                "sync_volume=%s "
+                                "jack_id=\"%s\" "
                                "card_properties=\"module-udev-detect.discovered=1\"",
                                path_get_card_id(path),
                                n,
                                d->card_name,
                                pa_yes_no(u->use_tsched),
                                pa_yes_no(u->ignore_dB),
-                                pa_yes_no(u->sync_volume));
-    pa_xfree(n);
+                                pa_yes_no(u->sync_volume),
+                                jack_input);

+    pa_xfree(n);
+    pa_xfree(jack_input);
+    u->card_name = d->card_name;
    pa_hashmap_put(u->devices, d->path, d);

    verify_access(u, d);
@@ -481,13 +539,11 @@ static void monitor_cb(
        goto fail;
    }

-    if (!path_get_card_id(udev_device_get_devpath(dev))) {
+    if (path_get_card_id(udev_device_get_devpath(dev))) {
+        process_device(u, dev);
        udev_device_unref(dev);
-        return;
    }

-    process_device(u, dev);
-    udev_device_unref(dev);
    return;

fail:
-- 
1.7.1