probe names: Fix cosmetics, add docs, fix off-by-one.

[libsigrok.git] / hardware / alsa / alsa.c

diff --git a/hardware/alsa/alsa.c b/hardware/alsa/alsa.c
index 3bf41605ea22620ac1853171500dcdfc784c6313..527a7e5de49fa992521e61360e403475379f2b78 100644 (file)
--- a/hardware/alsa/alsa.c
+++ b/hardware/alsa/alsa.c
@@ -18,12 +18,13 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  */
 
+#include "config.h" /* Must come before sigrok.h */
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
-#include <sigrok.h>
 #include <alsa/asoundlib.h>
-#include "config.h"
+#include "sigrok.h"
+#include "sigrok-internal.h"
 
 #define NUM_PROBES 2
 #define SAMPLE_WIDTH 16
@@ -35,6 +36,12 @@ static int capabilities[] = {
        SR_HWCAP_CONTINUOUS,
 };
 
+static const char *probe_names[NUM_PROBES + 1] = {
+       "0",
+       "1",
+       NULL,
+};
+
 static GSList *device_instances = NULL;
 
 struct alsa {
@@ -53,10 +60,10 @@ static int hw_init(const char *deviceinfo)
        /* Avoid compiler warnings. */
        deviceinfo = deviceinfo;
 
-       alsa = malloc(sizeof(struct alsa));
-       if (!alsa)
+       if (!(alsa = g_try_malloc0(sizeof(struct alsa)))) {
+               sr_err("alsa: %s: alsa malloc failed", __func__);
                return 0;
-       memset(alsa, 0, sizeof(struct alsa));
+       }
 
        sdi = sr_device_instance_new(0, SR_ST_ACTIVE, "alsa", NULL, NULL);
        if (!sdi)
@@ -68,7 +75,7 @@ static int hw_init(const char *deviceinfo)
 
        return 1;
 free_alsa:
-       free(alsa);
+       g_free(alsa);
        return 0;
 }
 
@@ -86,14 +93,14 @@ static int hw_opendev(int device_index)
                                        SND_PCM_STREAM_CAPTURE, 0);
        if (err < 0) {
                sr_warn("cannot open audio device %s (%s)", AUDIO_DEV,
-                               snd_strerror(err));
+                       snd_strerror(err));
                return SR_ERR;
        }
 
        err = snd_pcm_hw_params_malloc(&alsa->hw_params);
        if (err < 0) {
                sr_warn("cannot allocate hardware parameter structure (%s)",
-                               snd_strerror(err));
+                       snd_strerror(err));
                return SR_ERR;
        }
 
@@ -107,21 +114,28 @@ static int hw_opendev(int device_index)
        return SR_OK;
 }
 
-static void hw_closedev(int device_index)
+static int hw_closedev(int device_index)
 {
        struct sr_device_instance *sdi;
        struct alsa *alsa;
 
-       if (!(sdi = sr_get_device_instance(device_instances, device_index)))
-               return;
-       alsa = sdi->priv;
-       if (!alsa)
-               return;
+       if (!(sdi = sr_get_device_instance(device_instances, device_index))) {
+               sr_err("alsa: %s: sdi was NULL", __func__);
+               return SR_ERR; /* TODO: SR_ERR_ARG? */
+       }
+
+       if (!(alsa = sdi->priv)) {
+               sr_err("alsa: %s: sdi->priv was NULL", __func__);
+               return SR_ERR; /* TODO: SR_ERR_ARG? */
+       }
 
+       // TODO: Return values of snd_*?
        if (alsa->hw_params)
                snd_pcm_hw_params_free(alsa->hw_params);
        if (alsa->capture_handle)
                snd_pcm_close(alsa->capture_handle);
+
+       return SR_OK;
 }
 
 static void hw_cleanup(void)
@@ -152,6 +166,9 @@ static void *hw_get_device_info(int device_index, int device_info_id)
        case SR_DI_NUM_PROBES:
                info = GINT_TO_POINTER(NUM_PROBES);
                break;
+       case SR_DI_PROBE_NAMES:
+               info = probe_names;
+               break;
        case SR_DI_CUR_SAMPLERATE:
                info = &alsa->cur_rate;
                break;
@@ -223,9 +240,10 @@ static int receive_data(int fd, int revents, void *user_data)
                        return FALSE;
                }
 
-               outb = malloc(sample_size * count);
-               if (!outb)
+               if (!(outb = g_try_malloc(sample_size * count))) {
+                       sr_err("alsa: %s: outb malloc failed", __func__);
                        return FALSE;
+               }
 
                for (i = 0; i < count; i++) {
                        sample = (struct sr_analog_sample *)
@@ -245,7 +263,7 @@ static int receive_data(int fd, int revents, void *user_data)
                packet.unitsize = sample_size;
                packet.payload = outb;
                sr_session_bus(user_data, &packet);
-               free(outb);
+               g_free(outb);
                alsa->limit_samples -= count;
 
        } while (alsa->limit_samples > 0);
@@ -318,15 +336,16 @@ static int hw_start_acquisition(int device_index, gpointer session_device_id)
                return SR_ERR;
        }
 
-       ufds = malloc(count * sizeof(struct pollfd));
-       if (!ufds)
+       if (!(ufds = g_try_malloc(count * sizeof(struct pollfd)))) {
+               sr_warn("alsa: %s: ufds malloc failed", __func__);
                return SR_ERR_MALLOC;
+       }
 
        err = snd_pcm_poll_descriptors(alsa->capture_handle, ufds, count);
        if (err < 0) {
                sr_warn("Unable to obtain poll descriptors (%s)",
                                snd_strerror(err));
-               free(ufds);
+               g_free(ufds);
                return SR_ERR;
        }
 
@@ -343,7 +362,7 @@ static int hw_start_acquisition(int device_index, gpointer session_device_id)
        header.num_logic_probes = 0;
        header.protocol_id = SR_PROTO_RAW;
        sr_session_bus(session_device_id, &packet);
-       free(ufds);
+       g_free(ufds);
 
        return SR_OK;
 }
@@ -356,17 +375,17 @@ static void hw_stop_acquisition(int device_index, gpointer session_device_id)
 }
 
 struct sr_device_plugin alsa_plugin_info = {
-       "alsa",
-       "ALSA driver",
-       1,
-       hw_init,
-       hw_cleanup,
-       hw_opendev,
-       hw_closedev,
-       hw_get_device_info,
-       hw_get_status,
-       hw_get_capabilities,
-       hw_set_configuration,
-       hw_start_acquisition,
-       hw_stop_acquisition,
+       .name = "alsa",
+       .longname = "ALSA driver",
+       .api_version = 1,
+       .init = hw_init,
+       .cleanup = hw_cleanup,
+       .opendev = hw_opendev,
+       .closedev = hw_closedev,
+       .get_device_info = hw_get_device_info,
+       .get_status = hw_get_status,
+       .get_capabilities = hw_get_capabilities,
+       .set_configuration = hw_set_configuration,
+       .start_acquisition = hw_start_acquisition,
+       .stop_acquisition = hw_stop_acquisition,
 };