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| author | Antony Pavlov <antonynpavlov@gmail.com> | 2012-01-18 10:31:56 +0400 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2012-01-19 09:46:02 +0100 |
| commit | cb76204fa88b8760ab53909893970eefbafa985f (patch) | |
| tree | 7f4102417a8851b1a8ca7c478cb72f44c1567441 /drivers/serial/serial_ns16550.c | |
| parent | b36dd65f150bb07c780c44b13f1f5b61cc2798f5 (diff) | |
| download | barebox-cb76204fa88b8760ab53909893970eefbafa985f.tar.gz barebox-cb76204fa88b8760ab53909893970eefbafa985f.tar.xz | |
ns16550: fix ier selection
The document "PC16550D Universal Asynchronous
Receiver Transmitter with FIFOs" (vers. June 1995,
http://www.national.com/ds/PC/PC16550D.pdf) states
that IER (Interrupt Enable Register) is accessible
if the bit DLAB = 0 (DLAB is bit 7 in LCR; in barebox
DLAB known as LCR_BKSE).
So before IER access we need set DLAB to 0.
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'drivers/serial/serial_ns16550.c')
| -rw-r--r-- | drivers/serial/serial_ns16550.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/serial/serial_ns16550.c b/drivers/serial/serial_ns16550.c index 802331df01..88ba836022 100644 --- a/drivers/serial/serial_ns16550.c +++ b/drivers/serial/serial_ns16550.c @@ -140,7 +140,9 @@ static inline unsigned int ns16550_calc_divisor(struct console_device *cdev, static void ns16550_serial_init_port(struct console_device *cdev) { /* initializing the device for the first time */ + ns16550_write(cdev, 0x00, lcr); /* select ier reg */ ns16550_write(cdev, 0x00, ier); + #ifdef CONFIG_DRIVER_SERIAL_NS16550_OMAP_EXTENSIONS ns16550_write(cdev, 0x07, mdr1); /* Disable */ #endif |