From a4416cd1ac7b48988f0f41a17769d65c71ffc504 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Tue, 24 Feb 2015 14:25:07 -0500 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- 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 625f81c..06bb2ce 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 @@ -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. */ 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 *); -- 2.7.4