linux-user: Add support for selecting alsa timer using ioctl

This patch implements functionality of following ioctl:

SNDRV_TIMER_IOCTL_SELECT - Selecting timer

    Selects the timer which id is specified. The timer id is specified in the
    following strcuture:

    struct snd_timer_select {
        struct snd_timer_id id;         /* timer ID */
        unsigned char reserved[32];     /* reserved */
    };

    A pointer to this structure should be passed as the third ioctl's argument.
    Before calling the ioctl, the field "tid" should be initialized with the id
    information for the timer which is to be selected. If there is no timer
    device with the specified id, the error ENODEV ("No such device") is
    returned.

Implementation notes:

    Ioctl implemented in this patch has a pointer to a
    'struct snd_timer_select' as its third argument.
    That is the reason why a corresponding definition
    was added in 'linux-user/syscall_types.h'. The rest
    of the implementation was straightforward.

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Filip Bozuta <Filip.Bozuta@rt-rk.com>
Message-Id: <1579117007-7565-11-git-send-email-Filip.Bozuta@rt-rk.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

linux-user/ioctls.h

@@ -470,6 +470,8 @@
         MK_PTR(MK_STRUCT(STRUCT_snd_timer_gparams)))
   IOCTL(SNDRV_TIMER_IOCTL_GSTATUS, IOC_RW,
         MK_PTR(MK_STRUCT(STRUCT_snd_timer_gstatus)))
+  IOCTL(SNDRV_TIMER_IOCTL_SELECT, IOC_W,
+        MK_PTR(MK_STRUCT(STRUCT_snd_timer_select)))
 
   IOCTL(HDIO_GETGEO, IOC_R, MK_PTR(MK_STRUCT(STRUCT_hd_geometry)))
   IOCTL(HDIO_GET_UNMASKINTR, IOC_R, MK_PTR(TYPE_INT))

linux-user/syscall_defs.h

@@ -2474,6 +2474,11 @@ struct target_snd_timer_gstatus {
     unsigned char reserved[32];
 };
 
+struct target_snd_timer_select {
+    struct target_snd_timer_id id;
+    unsigned char reserved[32];
+};
+
 /* alsa timer ioctls */
 #define TARGET_SNDRV_TIMER_IOCTL_PVERSION     TARGET_IOR('T', 0x00, int)
 #define TARGET_SNDRV_TIMER_IOCTL_NEXT_DEVICE  TARGET_IOWR('T', 0x01,           \
@@ -2484,6 +2489,8 @@ struct target_snd_timer_gstatus {
                                                 struct target_snd_timer_gparams)
 #define TARGET_SNDRV_TIMER_IOCTL_GSTATUS      TARGET_IOWR('T', 0x05,           \
                                                 struct target_snd_timer_gstatus)
+#define TARGET_SNDRV_TIMER_IOCTL_SELECT       TARGET_IOW('T', 0x10,            \
+                                                struct target_snd_timer_select)
 
 /* vfat ioctls */
 #define TARGET_VFAT_IOCTL_READDIR_BOTH    TARGET_IORU('r', 1)

linux-user/syscall_types.h

@@ -116,6 +116,10 @@ STRUCT(snd_timer_gstatus,
        TYPE_ULONG, /* resolution_den */
        MK_ARRAY(TYPE_CHAR, 32)) /* reserved */
 
+STRUCT(snd_timer_select,
+       MK_STRUCT(STRUCT_snd_timer_id), /* id */
+       MK_ARRAY(TYPE_CHAR, 32)) /* reserved */
+
 /* loop device ioctls */
 STRUCT(loop_info,
        TYPE_INT,                 /* lo_number */