[PATCH 2/3] serial: allow passing in hardware bug info via platform device

From: Paul Gortmaker
Date: Thu Dec 01 2011 - 18:48:21 EST


The normal arch hook into the 8250 serial world is via passing
in a plat_serial8250_port struct. However, this struct does
not have a bugs field, so there is no way to have the arch
code pass in info about known uart issues.

Add a bug field to the plat_serial8250_port struct, so that the
arch can pass in this information. Also don't do a blanket
overwrite of the bugs setting in the 8250.c driver. Finally,
relocate the known bug #define list to a globally visible header
so that the arch can assign any appropriate values from the list.

Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
drivers/tty/serial/8250.c | 3 ++-
drivers/tty/serial/8250.h | 5 -----
include/linux/serial_8250.h | 6 ++++++
3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/8250.c b/drivers/tty/serial/8250.c
index 7c94dbc..f99f27c 100644
--- a/drivers/tty/serial/8250.c
+++ b/drivers/tty/serial/8250.c
@@ -1101,7 +1101,6 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
spin_lock_irqsave(&up->port.lock, flags);

up->capabilities = 0;
- up->port.bugs = 0;

if (!(up->port.flags & UPF_BUGGY_UART)) {
/*
@@ -3075,6 +3074,7 @@ static int __devinit serial8250_probe(struct platform_device *dev)
port.serial_out = p->serial_out;
port.handle_irq = p->handle_irq;
port.set_termios = p->set_termios;
+ port.bugs = p->bugs;
port.pm = p->pm;
port.dev = &dev->dev;
port.irqflags |= irqflag;
@@ -3225,6 +3225,7 @@ int serial8250_register_port(struct uart_port *port)
uart->port.regshift = port->regshift;
uart->port.iotype = port->iotype;
uart->port.flags = port->flags | UPF_BOOT_AUTOCONF;
+ uart->port.bugs = port->bugs;
uart->port.mapbase = port->mapbase;
uart->port.private_data = port->private_data;
if (port->dev)
diff --git a/drivers/tty/serial/8250.h b/drivers/tty/serial/8250.h
index 6edf4a6..caefe00 100644
--- a/drivers/tty/serial/8250.h
+++ b/drivers/tty/serial/8250.h
@@ -44,11 +44,6 @@ struct serial8250_config {
#define UART_CAP_UUE (1 << 12) /* UART needs IER bit 6 set (Xscale) */
#define UART_CAP_RTOIE (1 << 13) /* UART needs IER bit 4 set (Xscale, Tegra) */

-#define UART_BUG_QUOT (1 << 0) /* UART has buggy quot LSB */
-#define UART_BUG_TXEN (1 << 1) /* UART has buggy TX IIR status */
-#define UART_BUG_NOMSR (1 << 2) /* UART has buggy MSR status bits (Au1x00) */
-#define UART_BUG_THRE (1 << 3) /* UART has buggy THRE reassertion */
-
#define PROBE_RSA (1 << 0)
#define PROBE_ANY (~0)

diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 1f05bbe..8c660af 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -14,6 +14,11 @@
#include <linux/serial_core.h>
#include <linux/platform_device.h>

+#define UART_BUG_QUOT (1 << 0) /* buggy quot LSB */
+#define UART_BUG_TXEN (1 << 1) /* buggy TX IIR status */
+#define UART_BUG_NOMSR (1 << 2) /* buggy MSR status bits (Au1x00) */
+#define UART_BUG_THRE (1 << 3) /* buggy THRE reassertion */
+
/*
* This is the platform device platform_data structure
*/
@@ -30,6 +35,7 @@ struct plat_serial8250_port {
unsigned char hub6;
upf_t flags; /* UPF_* flags */
unsigned int type; /* If UPF_FIXED_TYPE */
+ unsigned short bugs; /* hardware specific bugs */
unsigned int (*serial_in)(struct uart_port *, int);
void (*serial_out)(struct uart_port *, int, int);
void (*set_termios)(struct uart_port *,
--
1.7.7

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