diff options
| author | Alexander Graf <agraf@suse.de> | 2016-08-15 17:48:51 +0200 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2016-09-06 13:18:19 -0400 |
| commit | 601147b06a708900c5352dc3dcc5d64271bf0d62 (patch) | |
| tree | 6edb09d09ac433ea4b296a7c1a8dcc3482c0972e /drivers/serial | |
| parent | 04a993fe116604b8c81fb116857dbc78e2500133 (diff) | |
serial: bcm283x_mu: Detect disabled serial device
On the raspberry pi, you can disable the serial port to gain dynamic frequency
scaling which can get handy at times.
However, in such a configuration the serial controller gets its rx queue filled
up with zero bytes which then happily get transmitted on to whoever calls
getc() today.
This patch adds detection logic for that case by checking whether the RX pin is
mapped to GPIO15 and disables the mini uart if it is not mapped properly.
That way we can leave the driver enabled in the tree and can determine during
runtime whether serial is usable or not, having a single binary that allows for
uart and non-uart operation.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'drivers/serial')
| -rw-r--r-- | drivers/serial/serial_bcm283x_mu.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/serial/serial_bcm283x_mu.c b/drivers/serial/serial_bcm283x_mu.c index 7357bbfb26..f4e062f0c4 100644 --- a/drivers/serial/serial_bcm283x_mu.c +++ b/drivers/serial/serial_bcm283x_mu.c @@ -73,6 +73,9 @@ static int bcm283x_mu_serial_probe(struct udevice *dev) struct bcm283x_mu_serial_platdata *plat = dev_get_platdata(dev); struct bcm283x_mu_priv *priv = dev_get_priv(dev); + if (plat->disabled) + return -ENODEV; + priv->regs = (struct bcm283x_mu_regs *)plat->base; return 0; |