From Ben Gras, add select support on /dev/random.

Change-Id: I47bf4c45285458ecc224df0564edf98afdb2c9d6

diff --git a/drivers/random/main.c b/drivers/random/main.c
index 1ded6f37e4a9964a4fbe349948c4091ee175a8ee..619a20d569ec2a8c5590e04eb2f478415ce21af6 100644 (file)
--- a/drivers/random/main.c
+++ b/drivers/random/main.c
@@ -28,15 +28,20 @@ static ssize_t r_write(devminor_t minor, u64_t position, endpoint_t endpt,
 static int r_open(devminor_t minor, int access, endpoint_t user_endpt);
 static void r_random(clock_t stamp);
 static void r_updatebin(int source, struct k_randomness_bin *rb);
+static int r_select(devminor_t, unsigned int, endpoint_t);
 
 /* Entry points to this driver. */
 static struct chardriver r_dtab = {
   .cdr_open    = r_open,       /* open device */
   .cdr_read    = r_read,       /* read from device */
   .cdr_write   = r_write,      /* write to device (seeding it) */
+  .cdr_select  = r_select,     /* select hook */
   .cdr_alarm   = r_random      /* get randomness from kernel (alarm) */
 };
 
+/* select requestor */
+static endpoint_t random_select = NONE;
+
 /* Buffer for the /dev/random number generator. */
 #define RANDOM_BUF_SIZE                1024
 static char random_buf[RANDOM_BUF_SIZE];
@@ -253,3 +258,16 @@ static void r_random(clock_t UNUSED(stamp))
        printf("RANDOM: sys_setalarm failed: %d\n", s);
 }
 
+/*===========================================================================*
+ *                             r_select                                     *
+ *===========================================================================*/
+static int r_select(devminor_t minor, unsigned int ops, endpoint_t ep)
+{
+       /* random device is always writable; it's infinitely readable
+        * once seeded, and doesn't block when it's not, so all operations
+        * are instantly possible. we ignore CDEV_OP_ERR.
+        */
+       int ready_ops = 0;
+       if (minor != RANDOM_DEV) return(EIO);
+       return ops & (CDEV_OP_RD | CDEV_OP_WR);
+}