tegra, serial8250: add ->handle_break() uart_port op

The "KT" serial port has another use case for a "received break" quirk,
so before adding another special case to the 8250 core take this
opportunity to push such quirks out of the core and into a uart_port op.

Stephen says:
"If the callback function is to no longer live in 8250.c itself,
 arch/arm/mach-tegra/devices.c isn't logically a good place to put it,
 and that file will be going away once we get rid of all the board files
 and move solely to device tree."

...so since 8250_pci.c houses all the quirks for pci serial devices this
quirk is similarly housed in of_serial.c.  Once the open firmware
conversion completes the infrastructure details
(include/linux/of_serial.h, and the export) can all be removed to make
this self contained to of_serial.c.

Cc: Nhan H Mai <nhan.h.mai@intel.com>
Cc: Colin Cross <ccross@android.com>
Cc: Olof Johansson <olof@lixom.net>
[stephen: kill CONFIG_SERIAL_TEGRA in favor just using CONFIG_ARCH_TEGRA]
Cc: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sudhakar Mamillapalli <sudhakar@fb.com>
Reported-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 3 insertions, 31 deletions

diff --git a/drivers/tty/serial/8250/8250.c b/drivers/tty/serial/8250/8250.c
index 5b149b466ec8..dffd623b7974 100644
--- a/drivers/tty/serial/8250/8250.c
+++ b/drivers/tty/serial/8250/8250.c
@@ -1332,27 +1332,6 @@ static void serial8250_enable_ms(struct uart_port *port)
 }
 
 /*
- * Clear the Tegra rx fifo after a break
- *
- * FIXME: This needs to become a port specific callback once we have a
- * framework for this
- */
-static void clear_rx_fifo(struct uart_8250_port *up)
-{
-	unsigned int status, tmout = 10000;
-	do {
-		status = serial_in(up, UART_LSR);
-		if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
-			status = serial_in(up, UART_RX);
-		else
-			break;
-		if (--tmout == 0)
-			break;
-		udelay(1);
-	} while (1);
-}
-
-/*
  * serial8250_rx_chars: processes according to the passed in LSR
  * value, and returns the remaining LSR bits not handled
  * by this Rx routine.
@@ -1386,20 +1365,10 @@ serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr)
 		up->lsr_saved_flags = 0;
 
 		if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
-			/*
-			 * For statistics only
-			 */
 			if (lsr & UART_LSR_BI) {
 				lsr &= ~(UART_LSR_FE | UART_LSR_PE);
 				port->icount.brk++;
 				/*
-				 * If tegra port then clear the rx fifo to
-				 * accept another break/character.
-				 */
-				if (port->type == PORT_TEGRA)
-					clear_rx_fifo(up);
-
-				/*
 				 * We do the SysRQ and SAK checking
 				 * here because otherwise the break
 				 * may get masked by ignore_status_mask
@@ -3037,6 +3006,7 @@ static int __devinit serial8250_probe(struct platform_device *dev)
 		port.serial_in		= p->serial_in;
 		port.serial_out		= p->serial_out;
 		port.handle_irq		= p->handle_irq;
+		port.handle_break	= p->handle_break;
 		port.set_termios	= p->set_termios;
 		port.pm			= p->pm;
 		port.dev		= &dev->dev;
@@ -3209,6 +3179,8 @@ int serial8250_register_port(struct uart_port *port)
 			uart->port.set_termios = port->set_termios;
 		if (port->pm)
 			uart->port.pm = port->pm;
+		if (port->handle_break)
+			uart->port.handle_break = port->handle_break;
 
 		if (serial8250_isa_config != NULL)
 			serial8250_isa_config(0, &uart->port,