qemu/include/hw/misc/led.h
Philippe Mathieu-Daudé ddb67f6402 hw/misc/led: Allow connecting from GPIO output
Some devices expose GPIO lines.

Add a GPIO qdev input to our LED device, so we can
connect a GPIO output using qdev_connect_gpio_out().

When used with GPIOs, the intensity can only be either
minium or maximum. This depends of the polarity of the
GPIO (which can be inverted).
Declare the GpioPolarity type to model the polarity.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Luc Michel <luc.michel@greensocs.com>
Message-Id: <20200912134041.946260-3-f4bug@amsat.org>
2020-10-26 13:44:58 +01:00

98 lines
2.6 KiB
C

/*
* QEMU single LED device
*
* Copyright (C) 2020 Philippe Mathieu-Daudé <f4bug@amsat.org>
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#ifndef HW_MISC_LED_H
#define HW_MISC_LED_H
#include "qom/object.h"
#include "hw/qdev-core.h"
#define TYPE_LED "led"
/**
* LEDColor: Color of a LED
*
* This set is restricted to physically available LED colors.
*
* LED colors from 'Table 1. Product performance of LUXEON Rebel Color
* Line' of the 'DS68 LUXEON Rebel Color Line' datasheet available at:
* https://www.lumileds.com/products/color-leds/luxeon-rebel-color/
*/
typedef enum { /* Coarse wavelength range */
LED_COLOR_VIOLET, /* 425 nm */
LED_COLOR_BLUE, /* 475 nm */
LED_COLOR_CYAN, /* 500 nm */
LED_COLOR_GREEN, /* 535 nm */
LED_COLOR_AMBER, /* 590 nm */
LED_COLOR_ORANGE, /* 615 nm */
LED_COLOR_RED, /* 630 nm */
} LEDColor;
struct LEDState {
/* Private */
DeviceState parent_obj;
/* Public */
uint8_t intensity_percent;
qemu_irq irq;
/* Properties */
char *description;
char *color;
/*
* Determines whether a GPIO is using a positive (active-high)
* logic (when used with GPIO, the intensity at reset is related
* to the GPIO polarity).
*/
bool gpio_active_high;
};
typedef struct LEDState LEDState;
DECLARE_INSTANCE_CHECKER(LEDState, LED, TYPE_LED)
/**
* led_set_intensity: Set the intensity of a LED device
* @s: the LED object
* @intensity_percent: intensity as percentage in range 0 to 100.
*/
void led_set_intensity(LEDState *s, unsigned intensity_percent);
/**
* led_get_intensity:
* @s: the LED object
*
* Returns: The LED intensity as percentage in range 0 to 100.
*/
unsigned led_get_intensity(LEDState *s);
/**
* led_set_state: Set the state of a LED device
* @s: the LED object
* @is_emitting: boolean indicating whether the LED is emitting
*
* This utility is meant for LED connected to GPIO.
*/
void led_set_state(LEDState *s, bool is_emitting);
/**
* led_create_simple: Create and realize a LED device
* @parentobj: the parent object
* @gpio_polarity: GPIO polarity
* @color: color of the LED
* @description: description of the LED (optional)
*
* Create the device state structure, initialize it, and
* drop the reference to it (the device is realized).
*
* Returns: The newly allocated and instantiated LED object.
*/
LEDState *led_create_simple(Object *parentobj,
GpioPolarity gpio_polarity,
LEDColor color,
const char *description);
#endif /* HW_MISC_LED_H */