[PATCH v3 3/3] tty: implement led triggers

From: Uwe Kleine-KÃnig
Date: Tue May 08 2018 - 06:06:52 EST

The rx trigger fires when data is pushed to the ldisc by the driver. This
is a bit later than the actual receiving of data but has the nice benefit
that it doesn't need adaption for each driver and isn't in the hot path.

Similarly the tx trigger fires when data was copied from userspace and is
given to the ldisc.

Signed-off-by: Uwe Kleine-KÃnig <u.kleine-koenig@xxxxxxxxxxxxxx>
---
arch/arm/boot/dts/imx25-logitech-baby.dts | 192 ++++++++++++++++++++++
drivers/tty/Kconfig | 7 +
drivers/tty/tty_buffer.c | 2 +
drivers/tty/tty_io.c | 3 +
drivers/tty/tty_port.c | 32 +++-
include/linux/tty.h | 22 +++
6 files changed, 256 insertions(+), 2 deletions(-)
create mode 100644 arch/arm/boot/dts/imx25-logitech-baby.dts

diff --git a/arch/arm/boot/dts/imx25-logitech-baby.dts b/arch/arm/boot/dts/imx25-logitech-baby.dts
new file mode 100644
index 000000000000..39cf763d228b
--- /dev/null
+++ b/arch/arm/boot/dts/imx25-logitech-baby.dts
@@ -0,0 +1,192 @@
+/dts-v1/;
+#include "imx25.dtsi"
+
+/ {
+ model = "Logitech MX25 Baby";
+ compatible = "logitech,baby", "fsl,imx25";
+
+ chosen {
+ linux,stdout-path = &uart2;
+ };
+};
+
+&i2c1 {
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_i2c1>;
+
+ clock-frequency = <100000>;
+
+ status = "okay";
+
+ codec: tlv320aic3104@18 {
+ compatible = "ti,tlv320aic310x";
+ reg = <0x18>;
+// HPVDD-supply
+// SPRVDD-supply
+// SPLVDD-supply
+// AVDD-supply
+// IOVDD-supply
+// DVDD-supply
+// ?gpio-reset
+// ?ai31xx-micbias-vg
+ };
+};
+
+&i2c2 {
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_i2c2>;
+
+ clock-frequency = <100000>;
+
+ status = "okay";
+
+ msp430@10 {
+ reg = <0x10>;
+ };
+};
+
+&iomuxc {
+ baby {
+ pinctrl_fec: fecgrp {
+ fsl,pins = <
+ MX25_PAD_FEC_MDC__FEC_MDC 0x040
+ MX25_PAD_FEC_MDIO__FEC_MDIO 0x1f0
+ MX25_PAD_FEC_TDATA0__FEC_TDATA0 0x040
+ MX25_PAD_FEC_TDATA1__FEC_TDATA1 0x040
+ MX25_PAD_A22__FEC_TDATA2 0x000
+ MX25_PAD_A23__FEC_TDATA3 0x000
+ MX25_PAD_FEC_TX_EN__FEC_TX_EN 0x040
+ MX25_PAD_FEC_RDATA0__FEC_RDATA0 0x0c0
+ MX25_PAD_FEC_RDATA1__FEC_RDATA1 0x0c0
+ MX25_PAD_A20__FEC_RDATA2 0x000
+ MX25_PAD_A21__FEC_RDATA3 0x000
+ MX25_PAD_FEC_RX_DV__FEC_RX_DV 0x0c0
+ MX25_PAD_FEC_TX_CLK__FEC_TX_CLK 0x1c0
+ MX25_PAD_A17__FEC_TX_ERR 0x080
+ MX25_PAD_A19__FEC_RX_ERR 0x080
+ MX25_PAD_A24__FEC_RX_CLK 0x000
+ MX25_PAD_A18__FEC_COL 0x080
+ MX25_PAD_A25__FEC_CRS 0x080
+
+ /*
+ * PHY_RESET:
+ * hwref 1: MX25_PIN_A10
+ * hwref 2: MX25_PIN_CSI_D7
+ * hwref 3+: MX25_PIN_PWM
+ */
+ MX25_PAD_PWM__GPIO_1_26 0x0c0
+ >;
+ };
+
+ pinctrl_i2c1: i2c1grp {
+ fsl,pins = <
+ MX25_PAD_I2C1_CLK__I2C1_CLK 0x0a8
+ MX25_PAD_I2C1_DAT__I2C1_DAT 0x0a8
+ >;
+ };
+
+ pinctrl_i2c2: i2c2grp {
+ fsl,pins = <
+ MX25_PAD_GPIO_C__I2C2_SCL 0x0e8
+ MX25_PAD_GPIO_D__I2C2_SDA 0x0a8
+ >;
+ };
+
+ pinctrl_nfc: nfcgrp {
+ fsl,pins = <
+ MX25_PAD_NFRB__NFRB 0x0
+ MX25_PAD_NFWP_B__NFWP_B 0x0
+ MX25_PAD_NFRE_B__NFRE_B 0x0
+ MX25_PAD_NFWE_B__NFWE_B 0x0
+ MX25_PAD_NFALE__NFALE 0x0
+ MX25_PAD_NFCLE__NFCLE 0x0
+ MX25_PAD_NF_CE0__NF_CE0 0x0
+ MX25_PAD_D0__D0 0x0
+ MX25_PAD_D1__D1 0x0
+ MX25_PAD_D2__D2 0x0
+ MX25_PAD_D3__D3 0x0
+ MX25_PAD_D4__D4 0x0
+ MX25_PAD_D5__D5 0x0
+ MX25_PAD_D6__D6 0x0
+ MX25_PAD_D7__D7 0x0
+ >;
+ };
+
+ pinctrl_uart2: uart2grp {
+ fsl,pins = <
+ MX25_PAD_UART2_RXD__UART2_RXD 0x1e0
+ MX25_PAD_UART2_TXD__UART2_TXD 0x0e0
+ /*
+ * These are configured in the vendor kernel,
+ * but the corresponding lines don't seem to be
+ * available:
+ * MX25_PAD_UART2_RTS__UART2_RTS 0x1e0
+ * MX25_PAD_UART2_CTS__UART2_CTS 0x0e0
+ */
+ >;
+ };
+ };
+};
+
+&fec {
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_fec>;
+
+ //phy-reset-gpios = <&gpio1 26 0>;
+ phy-handle = <&ethphy>;
+ phy-mode = "rmii";
+
+ status = "okay";
+
+ mdio {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ ethphy: ethernet-phy@1 {
+ compatible = "ethernet-phy-ieee802.3-c22";
+ reg = <1>;
+ max-speed = <100>;
+ };
+ };
+};
+
+&kpp {
+ linux,keymap = <
+ 0x000000cf /* KEY_PLAY */
+ 0x0001004e /* KEY_KPPLUS */
+ 0x00020069 /* KEY_LEFT */
+ 0x00030066 /* KEY_HOME */
+ 0x0100003b /* KEY_F1 */
+ 0x010100a4 /* KEY_PLAYPAUSE */
+ 0x010200a3 /* KEY_NEXTSONG */
+ 0x010300a5 /* KEY_PREVIOUSSONG */
+ 0x0200003f /* KEY_F5 */
+ 0x0201003e /* KEY_F4 */
+ 0x0202003d /* KEY_F3 */
+ 0x0203003c /* KEY_F2 */
+ 0x03000000 /* KEY_RESERVED */
+ 0x03010000 /* KEY_RESERVED */
+ 0x0302008e /* KEY_SLEEP */
+ 0x03030040 /* KEY_F6 */
+ >;
+
+ status = "okay";
+};
+
+&nfc {
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_nfc>;
+
+ nand-on-flash-bbt;
+ nand-bus-width = <8>;
+ nand-ecc-mode = "hw";
+
+ status = "okay";
+};
+
+&uart2 {
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_uart2>;
+
+ status = "okay";
+};
diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
index 0840d27381ea..b119c0fa1f5a 100644
--- a/drivers/tty/Kconfig
+++ b/drivers/tty/Kconfig
@@ -41,6 +41,13 @@ config VT
If unsure, say Y, or else you won't be able to do much with your new
shiny Linux system :-)

+config TTY_LEDS_TRIGGERS
+ bool "Enable support for TTY actions making LEDs blink"
+ depends on LEDS_TRIGGERS
+ ---help---
+ This enable support for tty triggers. It provides two LED triggers
+ (rx and tx) for each TTY.
+
config CONSOLE_TRANSLATIONS
depends on VT
default y
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index c996b6859c5e..364080ce8e91 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -521,6 +521,8 @@ static void flush_to_ldisc(struct work_struct *work)
continue;
}

+ tty_led_trigger_rx(port);
+
count = receive_buf(port, head, count);
if (!count)
break;
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 7c838b90a31d..8ef597dc0c3d 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -955,6 +955,9 @@ static inline ssize_t do_tty_write(
ret = -EFAULT;
if (copy_from_user(tty->write_buf, buf, size))
break;
+
+ tty_led_trigger_tx(tty->port);
+
ret = write(tty, file, tty->write_buf, size);
if (ret <= 0)
break;
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index 25d736880013..d313edfa6315 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -37,6 +37,8 @@ static int tty_port_default_receive_buf(struct tty_port *port,

ret = tty_ldisc_receive_buf(disc, p, (char *)f, count);

+ tty_led_trigger_rx(port);
+
tty_ldisc_deref(disc);

return ret;
@@ -163,8 +165,31 @@ struct device *tty_port_register_device_attr_serdev(struct tty_port *port,
return dev;
}

- return tty_register_device_attr(driver, index, device, drvdata,
- attr_grp);
+ if (IS_ENABLED(CONFIG_TTY_LEDS_TRIGGERS)) {
+ int ret;
+
+ ret = led_trigger_register_format(&port->led_trigger_rx,
+ "%s%d-rx", driver->name, index);
+ if (ret < 0)
+ pr_warn("Failed to register rx trigger for %s%d (%d)\n",
+ driver->name, index, ret);
+
+ ret = led_trigger_register_format(&port->led_trigger_tx,
+ "%s%d-tx", driver->name, index);
+ if (ret < 0)
+ pr_warn("Failed to register tx trigger for %s%d (%d)\n",
+ driver->name, index, ret);
+ }
+
+ dev = tty_register_device_attr(driver, index,
+ device, drvdata, attr_grp);
+
+ if (IS_ENABLED(CONFIG_TTY_LEDS_TRIGGERS) && IS_ERR(dev)) {
+ led_trigger_unregister_simple(port->led_trigger_tx);
+ led_trigger_unregister_simple(port->led_trigger_rx);
+ }
+
+ return dev;
}
EXPORT_SYMBOL_GPL(tty_port_register_device_attr_serdev);

@@ -206,6 +231,9 @@ void tty_port_unregister_device(struct tty_port *port,
if (ret == 0)
return;

+ led_trigger_unregister_simple(port->led_trigger_rx);
+ led_trigger_unregister_simple(port->led_trigger_tx);
+
tty_unregister_device(driver, index);
}
EXPORT_SYMBOL_GPL(tty_port_unregister_device);
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 1dd587ba6d88..7e48de671bfa 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -13,6 +13,7 @@
#include <uapi/linux/tty.h>
#include <linux/rwsem.h>
#include <linux/llist.h>
+#include <linux/leds.h>


/*
@@ -249,8 +250,29 @@ struct tty_port {
set to size of fifo */
struct kref kref; /* Ref counter */
void *client_data;
+
+ struct led_trigger *led_trigger_rx;
+ struct led_trigger *led_trigger_tx;
};

+static inline void tty_led_trigger(struct led_trigger *trig)
+{
+ unsigned long delay_ms = 50;
+
+ if (IS_ENABLED(CONFIG_TTY_LEDS_TRIGGERS))
+ led_trigger_blink_oneshot(trig, &delay_ms, &delay_ms, 0);
+}
+
+static inline void tty_led_trigger_rx(struct tty_port *port)
+{
+ tty_led_trigger(port->led_trigger_rx);
+}
+
+static inline void tty_led_trigger_tx(struct tty_port *port)
+{
+ tty_led_trigger(port->led_trigger_tx);
+}
+
/* tty_port::iflags bits -- use atomic bit ops */
#define TTY_PORT_INITIALIZED 0 /* device is initialized */
#define TTY_PORT_SUSPENDED 1 /* device is suspended */
--
2.17.0