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path: root/drivers/tty/serial/8250/8250_bcm2835aux.c
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2017-05-24serial: 8250: Add CAP_MINI, set for bcm2835auxPhil Elwell
The AUX/mini-UART in the BCM2835 family of procesors is a cut-down 8250 clone. In particular it is lacking support for the following features: CSTOPB PARENB PARODD CMSPAR CS5 CS6 Add a new capability (UART_CAP_MINI) that exposes the restrictions to the user of the termios API by turning off the unsupported features in the request. N.B. It is almost possible to automatically discover the missing features by reading back the LCR register, but the CSIZE bits don't cooperate (contrary to the documentation, both bits are significant, but CS5 and CS6 are mapped to CS7) and the code is much longer. See: https://github.com/raspberrypi/linux/issues/1561 Signed-off-by: Phil Elwell <phil@raspberrypi.org> Acked-by: Eric Anholt <eric@anholt.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-14serial: bcm2835: fix unsigned int issue with irqMartin Sperl
Fixes error condition check when requesting the irq, that would not trigger because of uart_port.irq being defined as unsigned int. Reported by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06serial: bcm2835: add driver for bcm2835-aux-uartMartin Sperl
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>