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authorLinus Torvalds <torvalds@linux-foundation.org>2012-01-30 15:17:21 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-30 15:17:21 -0800
commit27ba234c8dfe86c96675d4ef275d1d3c1f5f7053 (patch)
tree9782cde6e3336e795f52fad2d2e17bcb0c2a8ccd /drivers/tty/serial/8250/8250_fsl.c
parent6bc2b95ee602659c1be6fac0f6aadeb0c5c29a5d (diff)
parent523b82e3734908fc9eff5d48de46c83e76e51641 (diff)
Merge tag 'tty-3.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Here are some tty/serial patches for 3.3-rc1 Big thing here is the movement of the 8250 serial drivers to their own directory, now that the patch churn has calmed down. Other than that, only minor stuff (omap patches were reverted as they were found to be wrong), and another broken driver removed from the system. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> * tag 'tty-3.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: serial: Kill off Moorestown code Revert "tty: serial: OMAP: ensure FIFO levels are set correctly in non-DMA mode" Revert "tty: serial: OMAP: transmit FIFO threshold interrupts don't wake the chip" serial: Fix wakeup init logic to speed up startup docbook: don't use serial_core.h in device-drivers book serial: amba-pl011: lock console writes against interrupts amba-pl011: do not disable RTS during shutdown tty: serial: OMAP: transmit FIFO threshold interrupts don't wake the chip tty: serial: OMAP: ensure FIFO levels are set correctly in non-DMA mode omap-serial: make serial_omap_restore_context depend on CONFIG_PM_RUNTIME omap-serial :Make the suspend/resume functions depend on CONFIG_PM_SLEEP. TTY: fix UV serial console regression jsm: Fixed EEH recovery error Updated TTY MAINTAINERS info serial: group all the 8250 related code together
Diffstat (limited to 'drivers/tty/serial/8250/8250_fsl.c')
-rw-r--r--drivers/tty/serial/8250/8250_fsl.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_fsl.c b/drivers/tty/serial/8250/8250_fsl.c
new file mode 100644
index 00000000000..f4d3c47b88e
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_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;
+}