diff options
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/8250_fsl.c | 63 | ||||
| -rw-r--r-- | drivers/tty/serial/Kconfig | 5 | ||||
| -rw-r--r-- | drivers/tty/serial/Makefile | 1 |
3 files changed, 69 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250_fsl.c b/drivers/tty/serial/8250_fsl.c new file mode 100644 index 00000000000..f4d3c47b88e --- /dev/null +++ b/drivers/tty/serial/8250_fsl.c @@ -0,0 +1,63 @@ +#include <linux/serial_reg.h> +#include <linux/serial_8250.h> + +#include "8250.h" + +/* + * Freescale 16550 UART "driver", Copyright (C) 2011 Paul Gortmaker. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This isn't a full driver; it just provides an alternate IRQ + * handler to deal with an errata. Everything else is just + * using the bog standard 8250 support. + * + * We follow code flow of serial8250_default_handle_irq() but add + * a check for a break and insert a dummy read on the Rx for the + * immediately following IRQ event. + * + * We re-use the already existing "bug handling" lsr_saved_flags + * field to carry the "what we just did" information from the one + * IRQ event to the next one. + */ + +int fsl8250_handle_irq(struct uart_port *port) +{ + unsigned char lsr, orig_lsr; + unsigned long flags; + unsigned int iir; + struct uart_8250_port *up = + container_of(port, struct uart_8250_port, port); + + spin_lock_irqsave(&up->port.lock, flags); + + iir = port->serial_in(port, UART_IIR); + if (iir & UART_IIR_NO_INT) { + spin_unlock_irqrestore(&up->port.lock, flags); + return 0; + } + + /* This is the WAR; if last event was BRK, then read and return */ + if (unlikely(up->lsr_saved_flags & UART_LSR_BI)) { + up->lsr_saved_flags &= ~UART_LSR_BI; + port->serial_in(port, UART_RX); + spin_unlock_irqrestore(&up->port.lock, flags); + return 1; + } + + lsr = orig_lsr = up->port.serial_in(&up->port, UART_LSR); + + if (lsr & (UART_LSR_DR | UART_LSR_BI)) + lsr = serial8250_rx_chars(up, lsr); + + serial8250_modem_status(up); + + if (lsr & UART_LSR_THRE) + serial8250_tx_chars(up); + + up->lsr_saved_flags = orig_lsr; + spin_unlock_irqrestore(&up->port.lock, flags); + return 1; +} diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 705d2dc39c9..fee9e04f42e 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -97,6 +97,11 @@ config SERIAL_8250_PNP This builds standard PNP serial support. You may be able to disable this feature if you only need legacy serial support. +config SERIAL_8250_FSL + bool + depends on SERIAL_8250 && PPC + default PPC + config SERIAL_8250_HP300 tristate depends on SERIAL_8250 && HP300 diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile index af57089ddb6..75eadb8d717 100644 --- a/drivers/tty/serial/Makefile +++ b/drivers/tty/serial/Makefile @@ -28,6 +28,7 @@ obj-$(CONFIG_SERIAL_8250_BOCA) += 8250_boca.o obj-$(CONFIG_SERIAL_8250_EXAR_ST16C554) += 8250_exar_st16c554.o obj-$(CONFIG_SERIAL_8250_HUB6) += 8250_hub6.o obj-$(CONFIG_SERIAL_8250_MCA) += 8250_mca.o +obj-$(CONFIG_SERIAL_8250_FSL) += 8250_fsl.o obj-$(CONFIG_SERIAL_8250_DW) += 8250_dw.o obj-$(CONFIG_SERIAL_AMBA_PL010) += amba-pl010.o obj-$(CONFIG_SERIAL_AMBA_PL011) += amba-pl011.o |