[PATCH 4/6] tegra, serial8250: add ->handle_break() uart_port op

From: Dan Williams
Date: Fri Apr 06 2012 - 14:34:27 EST

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.

Cc: Nhan H Mai <nhan.h.mai@xxxxxxxxx>
Cc: Colin Cross <ccross@xxxxxxxxxxx>
Cc: Olof Johansson <olof@xxxxxxxxx>
Cc: Stephen Warren <swarren@xxxxxxxxxx>
Acked-by: Sudhakar Mamillapalli <sudhakar@xxxxxx>
Reported-by: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
arch/arm/mach-tegra/board-harmony.c | 1 +
arch/arm/mach-tegra/board-paz00.c | 2 ++
arch/arm/mach-tegra/board-seaboard.c | 1 +
arch/arm/mach-tegra/board-trimslice.c | 1 +
arch/arm/mach-tegra/devices.c | 18 +++++++++++++++++
arch/arm/mach-tegra/devices.h | 2 ++
drivers/tty/serial/8250/8250.c | 34 +++------------------------------
include/linux/serial_8250.h | 1 +
include/linux/serial_core.h | 5 +++++
9 files changed, 34 insertions(+), 31 deletions(-)

diff --git a/arch/arm/mach-tegra/board-harmony.c b/arch/arm/mach-tegra/board-harmony.c
index 789bdc9..7a4755b 100644
--- a/arch/arm/mach-tegra/board-harmony.c
+++ b/arch/arm/mach-tegra/board-harmony.c
@@ -52,6 +52,7 @@ static struct plat_serial8250_port debug_uart_platform_data[] = {
.irq = INT_UARTD,
.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_TYPE,
.type = PORT_TEGRA,
+ .handle_break = tegra_serial_handle_break,
.iotype = UPIO_MEM,
.regshift = 2,
.uartclk = 216000000,
diff --git a/arch/arm/mach-tegra/board-paz00.c b/arch/arm/mach-tegra/board-paz00.c
index 330afdf..9426e76 100644
--- a/arch/arm/mach-tegra/board-paz00.c
+++ b/arch/arm/mach-tegra/board-paz00.c
@@ -55,6 +55,7 @@ static struct plat_serial8250_port debug_uart_platform_data[] = {
.irq = INT_UARTA,
.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_TYPE,
.type = PORT_TEGRA,
+ .handle_break = tegra_serial_handle_break,
.iotype = UPIO_MEM,
.regshift = 2,
.uartclk = 216000000,
@@ -65,6 +66,7 @@ static struct plat_serial8250_port debug_uart_platform_data[] = {
.irq = INT_UARTC,
.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_TYPE,
.type = PORT_TEGRA,
+ .handle_break = tegra_serial_handle_break,
.iotype = UPIO_MEM,
.regshift = 2,
.uartclk = 216000000,
diff --git a/arch/arm/mach-tegra/board-seaboard.c b/arch/arm/mach-tegra/board-seaboard.c
index ebac65f..11b8d27 100644
--- a/arch/arm/mach-tegra/board-seaboard.c
+++ b/arch/arm/mach-tegra/board-seaboard.c
@@ -47,6 +47,7 @@ static struct plat_serial8250_port debug_uart_platform_data[] = {
/* Memory and IRQ filled in before registration */
.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_TYPE,
.type = PORT_TEGRA,
+ .handle_break = tegra_serial_handle_break,
.iotype = UPIO_MEM,
.regshift = 2,
.uartclk = 216000000,
diff --git a/arch/arm/mach-tegra/board-trimslice.c b/arch/arm/mach-tegra/board-trimslice.c
index cd52820..e7763ff 100644
--- a/arch/arm/mach-tegra/board-trimslice.c
+++ b/arch/arm/mach-tegra/board-trimslice.c
@@ -48,6 +48,7 @@ static struct plat_serial8250_port debug_uart_platform_data[] = {
.irq = INT_UARTA,
.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_TYPE,
.type = PORT_TEGRA,
+ .handle_break = tegra_serial_handle_break,
.iotype = UPIO_MEM,
.regshift = 2,
.uartclk = 216000000,
diff --git a/arch/arm/mach-tegra/devices.c b/arch/arm/mach-tegra/devices.c
index 7a2a02d..d9301bc 100644
--- a/arch/arm/mach-tegra/devices.c
+++ b/arch/arm/mach-tegra/devices.c
@@ -17,11 +17,13 @@
*/


+#include <linux/delay.h>
#include <linux/resource.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/fsl_devices.h>
#include <linux/serial_8250.h>
+#include <linux/serial_reg.h>
#include <linux/i2c-tegra.h>
#include <linux/platform_data/tegra_usb.h>
#include <asm/pmu.h>
@@ -704,3 +706,19 @@ struct platform_device tegra_pcm_device = {
.name = "tegra-pcm-audio",
.id = -1,
};
+
+void tegra_serial_handle_break(struct uart_port *p)
+{
+ unsigned int status, tmout = 10000;
+
+ do {
+ status = p->serial_in(p, UART_LSR);
+ if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
+ status = p->serial_in(p, UART_RX);
+ else
+ break;
+ if (--tmout == 0)
+ break;
+ udelay(1);
+ } while (1);
+}
diff --git a/arch/arm/mach-tegra/devices.h b/arch/arm/mach-tegra/devices.h
index 873ecb2..c2253be 100644
--- a/arch/arm/mach-tegra/devices.h
+++ b/arch/arm/mach-tegra/devices.h
@@ -20,6 +20,7 @@
#define __MACH_TEGRA_DEVICES_H

#include <linux/platform_device.h>
+#include <linux/serial_8250.h>

extern struct platform_device tegra_gpio_device;
extern struct platform_device tegra_pinmux_device;
@@ -49,4 +50,5 @@ extern struct platform_device tegra_i2s_device2;
extern struct platform_device tegra_das_device;
extern struct platform_device tegra_pcm_device;

+void tegra_serial_handle_break(struct uart_port *p);
#endif
diff --git a/drivers/tty/serial/8250/8250.c b/drivers/tty/serial/8250/8250.c
index 0e2c703..d1e0b3d 100644
--- a/drivers/tty/serial/8250/8250.c
+++ b/drivers/tty/serial/8250/8250.c
@@ -1353,27 +1353,6 @@ 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.
@@ -1406,20 +1385,10 @@ 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);
up->port.icount.brk++;
/*
- * If tegra port then clear the rx fifo to
- * accept another break/character.
- */
- if (up->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
@@ -3047,6 +3016,7 @@ 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;
@@ -3219,6 +3189,8 @@ 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,
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 8f012f8..a522fd9 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -38,6 +38,7 @@ struct plat_serial8250_port {
int (*handle_irq)(struct uart_port *);
void (*pm)(struct uart_port *, unsigned int state,
unsigned old);
+ void (*handle_break)(struct uart_port *);
};

/*
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index cbb3d12..82f6147 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -308,6 +308,7 @@ struct uart_port {
int (*handle_irq)(struct uart_port *);
void (*pm)(struct uart_port *, unsigned int state,
unsigned int old);
+ void (*handle_break)(struct uart_port *);
unsigned int irq; /* irq number */
unsigned long irqflags; /* irq flags */
unsigned int uartclk; /* base uart clock */
@@ -521,6 +522,10 @@ uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
static inline int uart_handle_break(struct uart_port *port)
{
struct uart_state *state = port->state;
+
+ if (port->handle_break)
+ port->handle_break(port);
+
#ifdef SUPPORT_SYSRQ
if (port->cons && port->cons->index == port->line) {
if (!port->sysrq) {

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/