[media] lirc_zilog: Restore checks for existence of the IR_tx object

This reverts commit 8090232a237ab62e22307fc060097da1a283dd66 and
adds an additional check for ir->tx == NULL.

The user may need us to handle an RX only unit.  Apparently
there are TV capture units in existence with Rx only wiring
and/or RX only firmware for the on-board Zilog Z8 IR unit.

Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 20 insertions, 7 deletions

diff --git a/drivers/staging/lirc/lirc_zilog.c b/drivers/staging/lirc/lirc_zilog.c
index 0aad0d7a74a3..7389b77ece8c 100644
--- a/drivers/staging/lirc/lirc_zilog.c
+++ b/drivers/staging/lirc/lirc_zilog.c
@@ -209,7 +209,8 @@ static int add_to_buf(struct IR *ir)
                                 return -ENODATA;
                         }
                         schedule_timeout((100 * HZ + 999) / 1000);
-                        ir->tx->need_boot = 1;
+                        if (ir->tx != NULL)
+                                ir->tx->need_boot = 1;
 
                         ++failures;
                         mutex_unlock(&ir->ir_lock);
@@ -1032,9 +1033,10 @@ static long ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
         int result;
         unsigned long mode, features = 0;
 
-        features |= LIRC_CAN_SEND_PULSE;
         if (ir->rx != NULL)
                 features |= LIRC_CAN_REC_LIRCCODE;
+        if (ir->tx != NULL)
+                features |= LIRC_CAN_SEND_PULSE;
 
         switch (cmd) {
         case LIRC_GET_LENGTH:
@@ -1061,9 +1063,15 @@ static long ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
                         result = -EINVAL;
                 break;
         case LIRC_GET_SEND_MODE:
+                if (!(features&LIRC_CAN_SEND_MASK))
+                        return -ENOSYS;
+
                 result = put_user(LIRC_MODE_PULSE, (unsigned long *) arg);
                 break;
         case LIRC_SET_SEND_MODE:
+                if (!(features&LIRC_CAN_SEND_MASK))
+                        return -ENOSYS;
+
                 result = get_user(mode, (unsigned long *) arg);
                 if (!result && mode != LIRC_MODE_PULSE)
                         return -EINVAL;
@@ -1242,8 +1250,10 @@ static int ir_remove(struct i2c_client *client)
         }
 
         /* Good-bye Tx */
-        i2c_set_clientdata(ir->tx->c, NULL);
-        kfree(ir->tx);
+        if (ir->tx != NULL) {
+                i2c_set_clientdata(ir->tx->c, NULL);
+                kfree(ir->tx);
+        }
 
         /* Good-bye IR */
         del_ir_device(ir);
@@ -1393,9 +1403,12 @@ static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id)
          * after registering with lirc as otherwise hotplug seems to take
          * 10s to create the lirc device.
          */
-        ret = tx_init(ir->tx);
-        if (ret != 0)
-                goto out_unregister;
+        if (ir->tx != NULL) {
+                /* Special TX init */
+                ret = tx_init(ir->tx);
+                if (ret != 0)
+                        goto out_unregister;
+        }
 
         zilog_info("probe of IR %s on %s (i2c-%d) done. IR unit ready.\n",
                    tx_probe ? "Tx" : "Rx", adap->name, adap->nr);