diff options
| author | Martin Sperl <kernel@martin.sperl.org> | 2016-01-17 12:15:30 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-02-06 23:13:30 -0800 |
| commit | bdc5f300958062a766518b81d5378f837149d5c1 (patch) | |
| tree | 1ee51fc232c44c27788afbafdd1801e5a4b43dea /drivers/tty/serial/8250/Kconfig | |
| parent | 45d7e9a51c995b4732eeecc121f40798e2220bea (diff) | |
| download | linux-bdc5f300958062a766518b81d5378f837149d5c1.tar.gz | |
serial: bcm2835: add driver for bcm2835-aux-uart
The bcm2835 SOC contains an auxiliary uart, which is very close to the ns16550 with some differences. The big difference is that the uart HW is not using an internal divider of 16 but 8, which results in an effictive baud-rate being twice the requested baud-rate. This driver handles this device correctly and handles the difference in the HW divider by scaling up the clock by a factor of 2. The approach to write a separate (wrapper) driver instead of using a multiplying clock and "ns16550" as compatibility in the device-tree has been recommended by Stephen Warren. Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Acked-by: Eric Anholt <eric@anholt.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/8250/Kconfig')
| -rw-r--r-- | drivers/tty/serial/8250/Kconfig | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig index b03cb5175113..67ad6b0d595b 100644 --- a/drivers/tty/serial/8250/Kconfig +++ b/drivers/tty/serial/8250/Kconfig @@ -272,6 +272,30 @@ config SERIAL_8250_ACORN system, say Y to this option. The driver can handle 1, 2, or 3 port cards. If unsure, say N. +config SERIAL_8250_BCM2835AUX + tristate "BCM2835 auxiliar mini UART support" + depends on ARCH_BCM2835 || COMPILE_TEST + depends on SERIAL_8250 && SERIAL_8250_SHARE_IRQ + help + Support for the BCM2835 auxiliar mini UART. + + Features and limitations of the UART are + Registers are similar to 16650 registers, + set bits in the control registers that are unsupported + are ignored and read back as 0 + 7/8 bit operation with 1 start and 1 stop bit + 8 symbols deep fifo for rx and tx + SW controlled RTS and SW readable CTS + Clock rate derived from system clock + Uses 8 times oversampling (compared to 16 times for 16650) + Missing break detection (but break generation) + Missing framing error detection + Missing parity bit + Missing receive time-out interrupt + Missing DCD, DSR, DTR and RI signals + + If unsure, say N. + config SERIAL_8250_FSL bool depends on SERIAL_8250_CONSOLE |