Prepare for 8250 split; decouple irq setup/teardown and handler from
core port operations.
Introduce setup_irq() and release_irq() 8250 driver methods; the 8250
core will use these methods to install and remove irq handling for
the given 8250 port.
Refactor irq chain linking/unlinking from 8250 core into
univ8250_setup_irq()/univ8250_release_irq() for the universal 8250 driver.
Signed-off-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_core.c | 83 +++++++++++++++++++++++--------------
include/linux/serial_8250.h | 15 +++++++
2 files changed, 68 insertions(+), 30 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 3bba930..d4bf1ab 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1890,6 +1890,48 @@ static void serial8250_backup_timeout(unsigned long data)
jiffies + uart_poll_timeout(&up->port) + HZ / 5);
}
+static int univ8250_setup_irq(struct uart_8250_port *up)
+{
+ struct uart_port *port = &up->port;
+ int retval = 0;
+
+ /*
+ * The above check will only give an accurate result the first time
+ * the port is opened so this value needs to be preserved.
+ */
+ if (up->bugs & UART_BUG_THRE) {
+ pr_debug("ttyS%d - using backup timer\n", serial_index(port));
+
+ up->timer.function = serial8250_backup_timeout;
+ up->timer.data = (unsigned long)up;
+ mod_timer(&up->timer, jiffies +
+ uart_poll_timeout(port) + HZ / 5);
+ }
+
+ /*
+ * If the "interrupt" for this port doesn't correspond with any
+ * hardware interrupt, we use a timer-based system. The original
+ * driver used to do this with IRQ0.
+ */
+ if (!port->irq) {
+ up->timer.data = (unsigned long)up;
+ mod_timer(&up->timer, jiffies + uart_poll_timeout(port));
+ } else
+ retval = serial_link_irq_chain(up);
+
+ return retval;
+}
+
+static void univ8250_release_irq(struct uart_8250_port *up)
+{
+ struct uart_port *port = &up->port;
+
+ del_timer_sync(&up->timer);
+ up->timer.function = serial8250_timeout;
+ if (port->irq)
+ serial_unlink_irq_chain(up);
+}
+
static unsigned int serial8250_tx_empty(struct uart_port *port)
{
struct uart_8250_port *up = up_to_u8250p(port);
@@ -2194,35 +2236,12 @@ int serial8250_do_startup(struct uart_port *port)
if ((!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) ||
up->port.flags & UPF_BUG_THRE) {
up->bugs |= UART_BUG_THRE;
- pr_debug("ttyS%d - using backup timer\n",
- serial_index(port));
}
}
- /*
- * The above check will only give an accurate result the first time
- * the port is opened so this value needs to be preserved.
- */
- if (up->bugs & UART_BUG_THRE) {
- up->timer.function = serial8250_backup_timeout;
- up->timer.data = (unsigned long)up;
- mod_timer(&up->timer, jiffies +
- uart_poll_timeout(port) + HZ / 5);
- }
-
- /*
- * If the "interrupt" for this port doesn't correspond with any
- * hardware interrupt, we use a timer-based system. The original
- * driver used to do this with IRQ0.
- */
- if (!port->irq) {
- up->timer.data = (unsigned long)up;
- mod_timer(&up->timer, jiffies + uart_poll_timeout(port));
- } else {
- retval = serial_link_irq_chain(up);
- if (retval)
- goto out;
- }
+ retval = up->ops->setup_irq(up);
+ if (retval)
+ goto out;
/*
* Now, initialize the UART
@@ -2381,10 +2400,7 @@ void serial8250_do_shutdown(struct uart_port *port)
serial_port_in(port, UART_RX);
serial8250_rpm_put(up);
- del_timer_sync(&up->timer);
- up->timer.function = serial8250_timeout;
- if (port->irq)
- serial_unlink_irq_chain(up);
+ up->ops->release_irq(up);
}
EXPORT_SYMBOL_GPL(serial8250_do_shutdown);
@@ -3084,6 +3100,11 @@ static struct uart_ops serial8250_pops = {
#endif
};
+static const struct uart_8250_ops univ8250_driver_ops = {
+ .setup_irq = univ8250_setup_irq,
+ .release_irq = univ8250_release_irq,
+};
+
static struct uart_8250_port serial8250_ports[UART_NR];
/**
@@ -3138,6 +3159,8 @@ static void __init serial8250_isa_init_ports(void)
up->timer.function = serial8250_timeout;
up->cur_iotype = 0xFF;
+ up->ops = &univ8250_driver_ops;
+
/*
* ALPHA_KLUDGE_MCR needs to be killed.
*/
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index ca9f87b..50735a9 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -60,6 +60,20 @@ enum {
};
struct uart_8250_dma;
+struct uart_8250_port;
+
+/**
+ * 8250 core driver operations
+ *
+ * @setup_irq() Setup irq handling. The universal 8250 driver links this
+ * port to the irq chain. Other drivers may @request_irq().
+ * @release_irq() Undo irq handling. The universal 8250 driver unlinks
+ * the port from the irq chain.
+ */
+struct uart_8250_ops {
+ int (*setup_irq)(struct uart_8250_port *);
+ void (*release_irq)(struct uart_8250_port *);
+};
/*
* This should be used by drivers which want to register
@@ -100,6 +114,7 @@ struct uart_8250_port {
unsigned char msr_saved_flags;
struct uart_8250_dma *dma;
+ const struct uart_8250_ops *ops;
/* 8250 specific callbacks */
int (*dl_read)(struct uart_8250_port *);
--
2.3.0
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