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serial: 8250: Separate legacy irq handling from core port operations 

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@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hifive-unleashed-5.1
Peter Hurley 2015-02-24 14:25:07 -05:00 committed by Greg Kroah-Hartman
parent 6e28157173
commit a4416cd1ac
2 changed files with 68 additions and 30 deletions
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83
drivers/tty/serial/8250/8250_core.c
View File

@ -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
@ -2380,10 +2399,7 @@ 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);
@ -3083,6 +3099,11 @@ 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];
/**
@ -3137,6 +3158,8 @@ 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.
*/

15
include/linux/serial_8250.h
View File

@ -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 *);