The 8250 UART driver provides rudimentary UART PM support and
a callback for systems to do more sophisticated power management.
However, there is no way yet for platform_device uarts to assign
something this internal callback.
This patch adds a callback to struct plat_serial8250_port and a
function to register this callback with 8250 driver internals.
Signed-off-by: Manuel Lauss <manuel.lauss@xxxxxxxxx>
---
drivers/serial/8250.c | 31 ++++++++++++++++++++++++++++---
include/linux/serial_8250.h | 6 ++++++
2 files changed, 34 insertions(+), 3 deletions(-)
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index a81ff7b..7802266 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2966,7 +2966,7 @@ static int __devinit serial8250_probe(struct platform_device *dev)
port.serial_out = p->serial_out;
port.dev = &dev->dev;
port.irqflags |= irqflag;
- ret = serial8250_register_port(&port);
+ ret = serial8250_register_port_with_pm(&port, p->pm);
if (ret < 0) {
dev_err(&dev->dev, "unable to register port at index %d "
"(IO%lx MEM%llx IRQ%d): %d\n", i,
@@ -3078,8 +3078,10 @@ static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *
}
/**
- * serial8250_register_port - register a serial port
+ * serial8250_register_port_with_pm - register a serial port and its
+ * power management callback.
* @port: serial port template
+ * @pm: PM callback for this port, can be NULL.
*
* Configure the serial port specified by the request. If the
* port exists and is in use, it is hung up and unregistered
@@ -3090,7 +3092,9 @@ static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *
*
* On success the port is ready to use and the line number is returned.
*/
-int serial8250_register_port(struct uart_port *port)
+int serial8250_register_port_with_pm(struct uart_port *port,
+ void(*pm)(struct uart_port *port, unsigned int state,
+ unsigned int old))
{
struct uart_8250_port *uart;
int ret = -ENOSPC;
@@ -3115,6 +3119,7 @@ int serial8250_register_port(struct uart_port *port)
uart->port.flags = port->flags | UPF_BOOT_AUTOCONF;
uart->port.mapbase = port->mapbase;
uart->port.private_data = port->private_data;
+ uart->pm = pm;
if (port->dev)
uart->port.dev = port->dev;
@@ -3140,6 +3145,26 @@ int serial8250_register_port(struct uart_port *port)
return ret;
}
+EXPORT_SYMBOL(serial8250_register_port_with_pm);
+
+/**
+ * serial8250_register_port - register a serial port
+ * @port: serial port template
+ *
+ * Configure the serial port specified by the request. If the
+ * port exists and is in use, it is hung up and unregistered
+ * first.
+ *
+ * The port is then probed and if necessary the IRQ is autodetected
+ * If this fails an error is returned.
+ *
+ * On success the port is ready to use and the line number is returned.
+ */
+int serial8250_register_port(struct uart_port *port)
+{
+ return serial8250_register_port_with_pm(port, NULL);
+}
+
EXPORT_SYMBOL(serial8250_register_port);
/**
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index fb46aba..25cc3fb 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -14,6 +14,9 @@
#include <linux/serial_core.h>
#include <linux/platform_device.h>
+typedef void(*plat8250_pm_func_t)(struct uart_port *port, unsigned int state,
+ unsigned int old_state);
+
/*
* This is the platform device platform_data structure
*/
@@ -32,6 +35,8 @@ struct plat_serial8250_port {
unsigned int type; /* If UPF_FIXED_TYPE */
unsigned int (*serial_in)(struct uart_port *, int);
void (*serial_out)(struct uart_port *, int, int);
+ void (*pm)(struct uart_port *port, unsigned int state,
+ unsigned int old_state);
};
/*
@@ -62,6 +67,7 @@ enum {
struct uart_port;
int serial8250_register_port(struct uart_port *);
+int serial8250_register_port_with_pm(struct uart_port *, plat8250_pm_func_t);
void serial8250_unregister_port(int line);
void serial8250_suspend_port(int line);
void serial8250_resume_port(int line);
--
1.7.0
