staging: iio: Add notrigger mode for generic_buffer

Some IIO devices do not use the triggers. This patch makes trigger setting
conditional so generic_buffer can be used when triggers are disabled.

Signed-off-by: Karol Wrona <k.wrona@samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 45 insertions, 32 deletions

diff --git a/drivers/staging/iio/Documentation/generic_buffer.c b/drivers/staging/iio/Documentation/generic_buffer.c
index 044ea196aa6f..2671bf9433cb 100644
--- a/drivers/staging/iio/Documentation/generic_buffer.c
+++ b/drivers/staging/iio/Documentation/generic_buffer.c
@@ -158,11 +158,12 @@ int main(int argc, char **argv)
         char *buffer_access;
         int scan_size;
         int noevents = 0;
+        int notrigger = 0;
         char *dummy;
 
         struct iio_channel_info *channels;
 
-        while ((c = getopt(argc, argv, "l:w:c:et:n:")) != -1) {
+        while ((c = getopt(argc, argv, "l:w:c:et:n:g")) != -1) {
                 switch (c) {
                 case 'n':
                         device_name = optarg;
@@ -183,6 +184,9 @@ int main(int argc, char **argv)
                 case 'l':
                         buf_len = strtoul(optarg, &dummy, 10);
                         break;
+                case 'g':
+                        notrigger = 1;
+                        break;
                 case '?':
                         return -1;
                 }
@@ -201,28 +205,32 @@ int main(int argc, char **argv)
         printf("iio device number being used is %d\n", dev_num);
 
         asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);
-        if (trigger_name == NULL) {
-                /*
-                 * Build the trigger name. If it is device associated its
-                 * name is <device_name>_dev[n] where n matches the device
-                 * number found above
-                 */
-                ret = asprintf(&trigger_name,
-                               "%s-dev%d", device_name, dev_num);
-                if (ret < 0) {
-                        ret = -ENOMEM;
-                        goto error_ret;
+
+        if (!notrigger) {
+                if (trigger_name == NULL) {
+                        /*
+                         * Build the trigger name. If it is device associated
+                         * its name is <device_name>_dev[n] where n matches
+                         * the device number found above.
+                         */
+                        ret = asprintf(&trigger_name,
+                                       "%s-dev%d", device_name, dev_num);
+                        if (ret < 0) {
+                                ret = -ENOMEM;
+                                goto error_ret;
+                        }
                 }
-        }
 
-        /* Verify the trigger exists */
-        trig_num = find_type_by_name(trigger_name, "trigger");
-        if (trig_num < 0) {
-                printf("Failed to find the trigger %s\n", trigger_name);
-                ret = -ENODEV;
-                goto error_free_triggername;
-        }
-        printf("iio trigger number being used is %d\n", trig_num);
+                /* Verify the trigger exists */
+                trig_num = find_type_by_name(trigger_name, "trigger");
+                if (trig_num < 0) {
+                        printf("Failed to find the trigger %s\n", trigger_name);
+                        ret = -ENODEV;
+                        goto error_free_triggername;
+                }
+                printf("iio trigger number being used is %d\n", trig_num);
+        } else
+                printf("trigger-less mode selected\n");
 
         /*
          * Parse the files in scan_elements to identify what channels are
@@ -246,14 +254,18 @@ int main(int argc, char **argv)
                 ret = -ENOMEM;
                 goto error_free_triggername;
         }
-        printf("%s %s\n", dev_dir_name, trigger_name);
-        /* Set the device trigger to be the data ready trigger found above */
-        ret = write_sysfs_string_and_verify("trigger/current_trigger",
-                                        dev_dir_name,
-                                        trigger_name);
-        if (ret < 0) {
-                printf("Failed to write current_trigger file\n");
-                goto error_free_buf_dir_name;
+
+        if (!notrigger) {
+                printf("%s %s\n", dev_dir_name, trigger_name);
+                /* Set the device trigger to be the data ready trigger found
+                 * above */
+                ret = write_sysfs_string_and_verify("trigger/current_trigger",
+                                                    dev_dir_name,
+                                                    trigger_name);
+                if (ret < 0) {
+                        printf("Failed to write current_trigger file\n");
+                        goto error_free_buf_dir_name;
+                }
         }
 
         /* Setup ring buffer parameters */
@@ -323,9 +335,10 @@ int main(int argc, char **argv)
         if (ret < 0)
                 goto error_close_buffer_access;
 
-        /* Disconnect the trigger - just write a dummy name. */
-        write_sysfs_string("trigger/current_trigger",
-                        dev_dir_name, "NULL");
+        if (!notrigger)
+                /* Disconnect the trigger - just write a dummy name. */
+                write_sysfs_string("trigger/current_trigger",
+                                   dev_dir_name, "NULL");
 
 error_close_buffer_access:
         close(fp);