2016-10-28 17:05:01

by Ed Blake

[permalink] [raw]
Subject: [PATCH v2 0/2] serial: Add IrDA support to 8250_dw driver

This patch set adds IrDA support to the 8250_dw driver. The first patch exposes
the set_ldisc() function in the 8250 driver so it can be overridden, and the
second patch adds a set_ldisc() function to the 8250_dw driver which enables /
disables IrDA SIR mode if supported.

v2:
The 8250_dw set_ldisc() function no longer tries to enable/disable IrDA SIR
mode if not supported by the hardware configuration.

Ed Blake (2):
serial: 8250: Expose set_ldisc function
serial: 8250_dw: Add support for IrDA SIR mode

drivers/tty/serial/8250/8250_core.c | 3 +++
drivers/tty/serial/8250/8250_dw.c | 24 ++++++++++++++++++++++++
drivers/tty/serial/8250/8250_port.c | 12 ++++++++++--
include/linux/serial_8250.h | 4 ++++
include/linux/serial_core.h | 2 ++
5 files changed, 43 insertions(+), 2 deletions(-)

--
1.9.1


2016-10-28 17:05:12

by Ed Blake

[permalink] [raw]
Subject: [PATCH v2 2/2] serial: 8250_dw: Add support for IrDA SIR mode

Add a set_ldisc function to enable/disable IrDA SIR mode according to
the new line discipline, if IrDA SIR mode is supported by the hardware
configuration.

Signed-off-by: Ed Blake <[email protected]>
---
drivers/tty/serial/8250/8250_dw.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 459d726..d6d41d6 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -53,6 +53,8 @@
/* Helper for fifo size calculation */
#define DW_UART_CPR_FIFO_SIZE(a) (((a >> 16) & 0xff) * 16)

+/* DesignWare specific register fields */
+#define DW_UART_MCR_SIRE BIT(6)

struct dw8250_data {
u8 usr_reg;
@@ -66,6 +68,7 @@ struct dw8250_data {

unsigned int skip_autocfg:1;
unsigned int uart_16550_compatible:1;
+ unsigned int sir_mode_supported:1;
};

static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value)
@@ -254,6 +257,22 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
serial8250_do_set_termios(p, termios, old);
}

+static void dw8250_set_ldisc(struct uart_port *p, struct ktermios *termios)
+{
+ struct dw8250_data *data = p->private_data;
+ unsigned int mcr = p->serial_in(p, UART_MCR);
+
+ if (data->sir_mode_supported) {
+ if (termios->c_line == N_IRDA)
+ mcr |= DW_UART_MCR_SIRE;
+ else
+ mcr &= ~DW_UART_MCR_SIRE;
+
+ p->serial_out(p, UART_MCR, mcr);
+ }
+ serial8250_do_set_ldisc(p, termios);
+}
+
/*
* dw8250_fallback_dma_filter will prevent the UART from getting just any free
* channel on platforms that have DMA engines, but don't have any channels
@@ -324,6 +343,7 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
static void dw8250_setup_port(struct uart_port *p)
{
struct uart_8250_port *up = up_to_u8250p(p);
+ struct dw8250_data *data = p->private_data;
u32 reg;

/*
@@ -357,6 +377,9 @@ static void dw8250_setup_port(struct uart_port *p)

if (reg & DW_UART_CPR_AFCE_MODE)
up->capabilities |= UART_CAP_AFE;
+
+ if (reg & DW_UART_CPR_SIR_MODE)
+ data->sir_mode_supported = true;
}

static int dw8250_probe(struct platform_device *pdev)
@@ -392,6 +415,7 @@ static int dw8250_probe(struct platform_device *pdev)
p->iotype = UPIO_MEM;
p->serial_in = dw8250_serial_in;
p->serial_out = dw8250_serial_out;
+ p->set_ldisc = dw8250_set_ldisc;

p->membase = devm_ioremap(dev, regs->start, resource_size(regs));
if (!p->membase)
--
1.9.1

2016-10-28 17:05:27

by Ed Blake

[permalink] [raw]
Subject: [PATCH v2 1/2] serial: 8250: Expose set_ldisc function

Expose set_ldisc() function so that it can be overridden with a
platform specific implementation.

Signed-off-by: Ed Blake <[email protected]>
---
drivers/tty/serial/8250/8250_core.c | 3 +++
drivers/tty/serial/8250/8250_port.c | 12 ++++++++++--
include/linux/serial_8250.h | 4 ++++
include/linux/serial_core.h | 2 ++
4 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 240a361..3ad8c80 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -830,6 +830,7 @@ static int serial8250_probe(struct platform_device *dev)
uart.port.handle_irq = p->handle_irq;
uart.port.handle_break = p->handle_break;
uart.port.set_termios = p->set_termios;
+ uart.port.set_ldisc = p->set_ldisc;
uart.port.get_mctrl = p->get_mctrl;
uart.port.pm = p->pm;
uart.port.dev = &dev->dev;
@@ -1023,6 +1024,8 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
/* Possibly override set_termios call */
if (up->port.set_termios)
uart->port.set_termios = up->port.set_termios;
+ if (up->port.set_ldisc)
+ uart->port.set_ldisc = up->port.set_ldisc;
if (up->port.get_mctrl)
uart->port.get_mctrl = up->port.get_mctrl;
if (up->port.set_mctrl)
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 1bfb6fd..38c5856 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -2690,8 +2690,7 @@ static unsigned int serial8250_get_baud_rate(struct uart_port *port,
serial8250_do_set_termios(port, termios, old);
}

-static void
-serial8250_set_ldisc(struct uart_port *port, struct ktermios *termios)
+void serial8250_do_set_ldisc(struct uart_port *port, struct ktermios *termios)
{
if (termios->c_line == N_PPS) {
port->flags |= UPF_HARDPPS_CD;
@@ -2707,7 +2706,16 @@ static unsigned int serial8250_get_baud_rate(struct uart_port *port,
}
}
}
+EXPORT_SYMBOL(serial8250_do_set_ldisc);

+static void
+serial8250_set_ldisc(struct uart_port *port, struct ktermios *termios)
+{
+ if (port->set_ldisc)
+ port->set_ldisc(port, termios);
+ else
+ serial8250_do_set_ldisc(port, termios);
+}

void serial8250_do_pm(struct uart_port *port, unsigned int state,
unsigned int oldstate)
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 48ec765..f350bf4 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -36,6 +36,8 @@ struct plat_serial8250_port {
void (*set_termios)(struct uart_port *,
struct ktermios *new,
struct ktermios *old);
+ void (*set_ldisc)(struct uart_port *,
+ struct ktermios *);
unsigned int (*get_mctrl)(struct uart_port *);
int (*handle_irq)(struct uart_port *);
void (*pm)(struct uart_port *, unsigned int state,
@@ -149,6 +151,8 @@ extern int early_serial8250_setup(struct earlycon_device *device,
const char *options);
extern void serial8250_do_set_termios(struct uart_port *port,
struct ktermios *termios, struct ktermios *old);
+extern void serial8250_do_set_ldisc(struct uart_port *port,
+ struct ktermios *termios);
extern unsigned int serial8250_do_get_mctrl(struct uart_port *port);
extern int serial8250_do_startup(struct uart_port *port);
extern void serial8250_do_shutdown(struct uart_port *port);
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 3442014..5d49488 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -123,6 +123,8 @@ struct uart_port {
void (*set_termios)(struct uart_port *,
struct ktermios *new,
struct ktermios *old);
+ void (*set_ldisc)(struct uart_port *,
+ struct ktermios *);
unsigned int (*get_mctrl)(struct uart_port *);
void (*set_mctrl)(struct uart_port *, unsigned int);
int (*startup)(struct uart_port *port);
--
1.9.1

2016-10-28 17:14:33

by Matwey V. Kornilov

[permalink] [raw]
Subject: Re: [PATCH v2 0/2] serial: Add IrDA support to 8250_dw driver

I like this idea. OMAP UART (8250_omap) also can be switched to IrDA
mode, but I don't know anyone who use it.

2016-10-28 20:04 GMT+03:00 Ed Blake <[email protected]>:
> This patch set adds IrDA support to the 8250_dw driver. The first patch exposes
> the set_ldisc() function in the 8250 driver so it can be overridden, and the
> second patch adds a set_ldisc() function to the 8250_dw driver which enables /
> disables IrDA SIR mode if supported.
>
> v2:
> The 8250_dw set_ldisc() function no longer tries to enable/disable IrDA SIR
> mode if not supported by the hardware configuration.
>
> Ed Blake (2):
> serial: 8250: Expose set_ldisc function
> serial: 8250_dw: Add support for IrDA SIR mode
>
> drivers/tty/serial/8250/8250_core.c | 3 +++
> drivers/tty/serial/8250/8250_dw.c | 24 ++++++++++++++++++++++++
> drivers/tty/serial/8250/8250_port.c | 12 ++++++++++--
> include/linux/serial_8250.h | 4 ++++
> include/linux/serial_core.h | 2 ++
> 5 files changed, 43 insertions(+), 2 deletions(-)
>
> --
> 1.9.1
>



--
With best regards,
Matwey V. Kornilov.
Sternberg Astronomical Institute, Lomonosov Moscow State University, Russia
119991, Moscow, Universitetsky pr-k 13, +7 (495) 9392382