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led: Add on board LED support

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This patch adds support for using on board LED through sysfs.
Commonly available LED parameters are supported.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
This commit is contained in:
Manivannan Sadhasivam
2017-08-25 18:01:19 +05:30
committed by Brendan Le Foll
parent e7b51f3b66
commit e1382ad845
8 changed files with 653 additions and 1 deletions
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1
api/mraa.h
View File

@@ -34,6 +34,7 @@ extern "C" {
#include "mraa/i2c.h"
#include "mraa/uart.h"
#include "mraa/uart_ow.h"
#include "mraa/led.h"
#ifdef __cplusplus
}

1
api/mraa.hpp
View File

@@ -31,3 +31,4 @@
#include "mraa/i2c.hpp"
#include "mraa/spi.hpp"
#include "mraa/uart.hpp"
#include "mraa/led.hpp"

111
api/mraa/led.h Normal file
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@@ -0,0 +1,111 @@
/*
* Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
* Copyright (c) 2017 Linaro Ltd.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#pragma once
/**
* @file
* @brief LED module
*
* LED is the Light Emitting Diode interface to libmraa. It is used to
* access the on board LED's via sysfs.
*
*/
#ifdef __cplusplus
extern "C" {
#endif
#include "common.h"
#include <stdio.h>
/**
* Opaque pointer definition to the internal struct _led
*/
typedef struct _led* mraa_led_context;
/**
* Initialise led_context, based on led function name.
* The structure of LED entry in sysfs is "devicename:colour:function"
* This api expects only one unique LED identifier which would be
* "function" name most often. For instance, `mraa_led_init("user4");`
*
* @param led Name of the LED
* @returns LED context or NULL
*/
mraa_led_context mraa_led_init(const char* led);
/**
* Set LED brightness
*
* @param dev LED context
* @param value Integer value to write
* @returns Result of operation
*/
mraa_result_t mraa_led_set_brightness(mraa_led_context dev, int value);
/**
* Read LED brightness
*
* @param dev LED context
* @returns Brightness value
*/
int mraa_led_read_brightness(mraa_led_context dev);
/**
* Read LED maximum brightness
*
* @param dev LED context
* @returns Maximum brightness value
*/
int mraa_led_read_max_brightness(mraa_led_context dev);
/**
* Set LED trigger
*
* @param dev LED context
* @param trigger Type of trigger to set
* @returns Result of operation
*/
mraa_result_t mraa_led_set_trigger(mraa_led_context dev, const char* trigger);
/**
* Clear active LED trigger
*
* @param dev LED context
* @returns Result of operation
*/
mraa_result_t mraa_led_clear_trigger(mraa_led_context dev);
/**
* Close LED file descriptors and free the context memory
*
* @param dev LED context
* @returns Result of operation
*/
mraa_result_t mraa_led_close(mraa_led_context dev);
#ifdef __cplusplus
}
#endif

139
api/mraa/led.hpp Normal file
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@@ -0,0 +1,139 @@
/*
* Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
* Copyright (c) 2017 Linaro Ltd.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#pragma once
#include "led.h"
#include "types.hpp"
#include <stdexcept>
namespace mraa
{
/**
* @brief API to Light Emitting Diode
*
* This file defines the LED interface for libmraa
*
*/
class Led
{
public:
/**
* Instantiates an LED object
*
* @param led LED fuction name to use
*/
Led(const char* led)
{
m_led = mraa_led_init(led);
if (m_led == NULL) {
throw std::invalid_argument("Invalid LED name specified");
}
}
/**
* LED Constructor, takes a pointer to a LED context and initialises
* the LED class
*
* @param led_context void * to LED context
*/
Led(void* led_context)
{
m_led = (mraa_led_context) led_context;
if (m_led == NULL) {
throw std::invalid_argument("Invalid LED name specified");
}
}
/**
* LED object destructor
*/
~Led()
{
mraa_led_close(m_led);
}
/**
* Set LED brightness value
*
* @param value Value to set LED brightness
* @return Result of operation
*/
Result
setBrightness(int value)
{
return (Result) mraa_led_set_brightness(m_led, value);
}
/**
* Read LED brightness value
*
* @return LED brightness value
*/
int
readBrightness()
{
return mraa_led_read_brightness(m_led);
}
/**
* Read LED maximum brightness value
*
* @return LED max brightness value
*/
int
readMaxBrightness()
{
return mraa_led_read_max_brightness(m_led);
}
/**
* Set LED trigger
*
* @param trigger Type of trigger to set
* @return Result of operation
*/
Result
trigger(const char* trigger)
{
return (Result) mraa_led_set_trigger(m_led, trigger);
}
/**
* Clear active LED trigger
*
* @return Result of operation
*/
Result
clearTrigger()
{
return (Result) mraa_led_clear_trigger(m_led);
}
private:
mraa_led_context m_led;
};
}

14
include/mraa_internal_types.h
View File

@@ -241,6 +241,20 @@ struct _iio {
};
#endif
/**
* A structure representing an LED device
*/
struct _led {
/*@{*/
int count; /**< total LED count in a platform */
char *led_name; /**< LED name */
char led_path[64]; /**< sysfs path of the LED */
int trig_fd; /**< trigger file descriptor */
int bright_fd; /**< brightness file descriptor */
int max_bright_fd; /**< maximum brightness file descriptor */
/*@}*/
};
/**
* A bitfield representing the capabilities of a pin.
*/

3
src/CMakeLists.txt
View File

@@ -28,6 +28,7 @@ set (mraa_LIB_SRCS_NOAUTO
${PROJECT_SOURCE_DIR}/src/spi/spi.c
${PROJECT_SOURCE_DIR}/src/aio/aio.c
${PROJECT_SOURCE_DIR}/src/uart/uart.c
${PROJECT_SOURCE_DIR}/src/led/led.c
${mraa_LIB_SRCS_NOAUTO}
)
@@ -236,7 +237,7 @@ mraa_create_install_pkgconfig (mraa.pc ${LIB_INSTALL_DIR}/pkgconfig)
if (DOXYGEN_FOUND)
set (CMAKE_SWIG_FLAGS -DDOXYGEN=${DOXYGEN_FOUND})
set (DOCCLASSES aio gpio i2c pwm spi uart)
set (DOCCLASSES aio gpio i2c pwm spi uart led)
# CPP class headers
foreach (_file ${DOCCLASSES})
add_custom_command (OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${_file}_class_doc.i

380
src/led/led.c Normal file
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@@ -0,0 +1,380 @@
/*
* Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
* Copyright (c) 2017 Linaro Ltd.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "led.h"
#include "mraa_internal.h"
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include <sys/errno.h>
#include <sys/stat.h>
#include <unistd.h>
#define SYSFS_CLASS_LED "/sys/class/leds"
#define MAX_SIZE 64
static mraa_result_t
mraa_led_get_trigfd(mraa_led_context dev)
{
char buf[MAX_SIZE];
snprintf(buf, MAX_SIZE, "%s/%s", dev->led_path, "trigger");
dev->trig_fd = open(buf, O_RDWR);
if (dev->trig_fd == -1) {
syslog(LOG_ERR, "led: trigger: Failed to open 'trigger': %s", strerror(errno));
return MRAA_ERROR_INVALID_RESOURCE;
}
return MRAA_SUCCESS;
}
static mraa_result_t
mraa_led_get_brightfd(mraa_led_context dev)
{
char buf[MAX_SIZE];
snprintf(buf, MAX_SIZE, "%s/%s", dev->led_path, "brightness");
dev->bright_fd = open(buf, O_RDWR);
if (dev->bright_fd == -1) {
syslog(LOG_ERR, "led: brightness: Failed to open 'brightness': %s", strerror(errno));
return MRAA_ERROR_INVALID_RESOURCE;
}
return MRAA_SUCCESS;
}
static mraa_result_t
mraa_led_get_maxbrightfd(mraa_led_context dev)
{
char buf[MAX_SIZE];
snprintf(buf, MAX_SIZE, "%s/%s", dev->led_path, "max_brightness");
dev->max_bright_fd = open(buf, O_RDONLY);
if (dev->max_bright_fd == -1) {
syslog(LOG_ERR, "led: max_brightness: Failed to open 'max_brightness': %s", strerror(errno));
return MRAA_ERROR_INVALID_RESOURCE;
}
return MRAA_SUCCESS;
}
static mraa_led_context
mraa_led_init_internal(const char* led)
{
DIR* dir;
struct dirent* entry;
int cnt = 0;
mraa_led_context dev = (mraa_led_context) calloc(1, sizeof(struct _led));
if (dev == NULL) {
syslog(LOG_CRIT, "led: init: Failed to allocate memory for context");
return NULL;
}
dev->led_name = NULL;
dev->trig_fd = -1;
dev->bright_fd = -1;
dev->max_bright_fd = -1;
if ((dir = opendir(SYSFS_CLASS_LED)) != NULL) {
/* get the led name from sysfs path */
while ((entry = readdir(dir)) != NULL) {
if (strstr((const char*) entry->d_name, led)) {
dev->led_name = (char*) entry->d_name;
}
cnt++;
}
}
dev->count = cnt;
if (dev->led_name == NULL) {
syslog(LOG_CRIT, "led: init: unknown device specified");
closedir(dir);
free(dev);
return NULL;
}
closedir(dir);
return dev;
}
mraa_led_context
mraa_led_init(const char* led)
{
mraa_led_context dev = NULL;
char directory[MAX_SIZE];
struct stat dir;
if (plat == NULL) {
syslog(LOG_ERR, "led: init: platform not initialised");
return NULL;
}
if (led == NULL) {
syslog(LOG_ERR, "led: init: invalid device specified");
return NULL;
}
dev = mraa_led_init_internal(led);
if (dev == NULL) {
return NULL;
}
snprintf(directory, MAX_SIZE, "%s/%s", SYSFS_CLASS_LED, dev->led_name);
if (stat(directory, &dir) == 0 && S_ISDIR(dir.st_mode)) {
syslog(LOG_NOTICE, "led: init: current user don't have access rights for using LED %s", dev->led_name);
}
strncpy(dev->led_path, (const char*) directory, sizeof(directory));
return dev;
}
mraa_result_t
mraa_led_set_brightness(mraa_led_context dev, int value)
{
char buf[MAX_SIZE];
int length;
if (dev == NULL) {
syslog(LOG_ERR, "led: set_brightness: context is invalid");
return MRAA_ERROR_INVALID_HANDLE;
}
if (dev->trig_fd != -1) {
close(dev->trig_fd);
dev->trig_fd = -1;
}
if (dev->max_bright_fd != -1) {
close(dev->max_bright_fd);
dev->max_bright_fd = -1;
}
if (dev->bright_fd == -1) {
if (mraa_led_get_brightfd(dev) != MRAA_SUCCESS) {
return MRAA_ERROR_INVALID_RESOURCE;
}
}
if (lseek(dev->bright_fd, 0, SEEK_SET) == -1) {
syslog(LOG_ERR, "led: set_brightness: Failed to lseek 'brightness': %s", strerror(errno));
return MRAA_ERROR_UNSPECIFIED;
}
length = snprintf(buf, sizeof(buf), "%d", value);
if (write(dev->bright_fd, buf, length * sizeof(char)) == -1) {
syslog(LOG_ERR, "led: set_brightness: Failed to write 'brightness': %s", strerror(errno));
return MRAA_ERROR_UNSPECIFIED;
}
return MRAA_SUCCESS;
}
int
mraa_led_read_brightness(mraa_led_context dev)
{
char buf[3];
if (dev == NULL) {
syslog(LOG_ERR, "led: read_brightness: context is invalid");
return MRAA_ERROR_INVALID_HANDLE;
}
if (dev->trig_fd != -1) {
close(dev->trig_fd);
dev->trig_fd = -1;
}
if (dev->max_bright_fd != -1) {
close(dev->max_bright_fd);
dev->max_bright_fd = -1;
}
if (dev->bright_fd == -1) {
if (mraa_led_get_brightfd(dev) != MRAA_SUCCESS) {
return MRAA_ERROR_INVALID_RESOURCE;
}
} else {
lseek(dev->bright_fd, 0, SEEK_SET);
}
if (read(dev->bright_fd, buf, 3 * sizeof(char)) == -1) {
syslog(LOG_ERR, "led: read_brightness: Failed to read 'brightness': %s", strerror(errno));
return MRAA_ERROR_UNSPECIFIED;
}
lseek(dev->bright_fd, 0, SEEK_SET);
return (int) atoi(buf);
}
int
mraa_led_read_max_brightness(mraa_led_context dev)
{
char buf[3];
if (dev == NULL) {
syslog(LOG_ERR, "led: read_max_brightness: context is invalid");
return MRAA_ERROR_INVALID_HANDLE;
}
if (dev->trig_fd != -1) {
close(dev->trig_fd);
dev->trig_fd = -1;
}
if (dev->bright_fd != -1) {
close(dev->bright_fd);
dev->bright_fd = -1;
}
if (dev->max_bright_fd == -1) {
if (mraa_led_get_maxbrightfd(dev) != MRAA_SUCCESS) {
return MRAA_ERROR_INVALID_RESOURCE;
}
} else {
lseek(dev->max_bright_fd, 0, SEEK_SET);
}
if (read(dev->max_bright_fd, buf, 3 * sizeof(char)) == -1) {
syslog(LOG_ERR, "led: read_max_brightness: Failed to read 'max_brightness': %s", strerror(errno));
return MRAA_ERROR_UNSPECIFIED;
}
lseek(dev->max_bright_fd, 0, SEEK_SET);
return (int) atoi(buf);
}
mraa_result_t
mraa_led_set_trigger(mraa_led_context dev, const char* trigger)
{
char buf[MAX_SIZE];
int length;
if (dev == NULL) {
syslog(LOG_ERR, "led: set_trigger: context is invalid");
return MRAA_ERROR_INVALID_HANDLE;
}
if (dev->bright_fd != -1) {
close(dev->bright_fd);
dev->bright_fd = -1;
}
if (dev->max_bright_fd != -1) {
close(dev->max_bright_fd);
dev->max_bright_fd = -1;
}
if (trigger == NULL) {
syslog(LOG_ERR, "led: trigger: invalid trigger specified");
return MRAA_ERROR_INVALID_RESOURCE;
}
if (dev->trig_fd == -1) {
if (mraa_led_get_trigfd(dev) != MRAA_SUCCESS) {
return MRAA_ERROR_INVALID_RESOURCE;
}
}
if (lseek(dev->trig_fd, 0, SEEK_SET) == -1) {
syslog(LOG_ERR, "led: set_trigger: Failed to lseek 'trigger': %s", strerror(errno));
return MRAA_ERROR_UNSPECIFIED;
}
length = snprintf(buf, sizeof(buf), "%s", trigger);
if (write(dev->trig_fd, buf, length * sizeof(char)) == -1) {
syslog(LOG_ERR, "led: set_trigger: Failed to write 'trigger': %s", strerror(errno));
return MRAA_ERROR_UNSPECIFIED;
}
return MRAA_SUCCESS;
}
mraa_result_t
mraa_led_clear_trigger(mraa_led_context dev)
{
char buf[1] = { '0' };
if (dev == NULL) {
syslog(LOG_ERR, "led: clear_trigger: context is invalid");
return MRAA_ERROR_INVALID_HANDLE;
}
if (dev->trig_fd != -1) {
close(dev->trig_fd);
dev->trig_fd = -1;
}
if (dev->max_bright_fd != -1) {
close(dev->max_bright_fd);
dev->max_bright_fd = -1;
}
if (dev->bright_fd == -1) {
if (mraa_led_get_brightfd(dev) != MRAA_SUCCESS) {
return MRAA_ERROR_INVALID_RESOURCE;
}
}
if (lseek(dev->bright_fd, 0, SEEK_SET) == -1) {
syslog(LOG_ERR, "led: clear_trigger: Failed to lseek 'brightness': %s", strerror(errno));
return MRAA_ERROR_UNSPECIFIED;
}
/* writing 0 to brightness clears trigger */
if (write(dev->bright_fd, buf, 1) == -1) {
syslog(LOG_ERR, "led: clear_trigger: Failed to write 'brightness': %s", strerror(errno));
return MRAA_ERROR_UNSPECIFIED;
}
return MRAA_SUCCESS;
}
mraa_result_t
mraa_led_close(mraa_led_context dev)
{
if (dev == NULL) {
syslog(LOG_ERR, "led: close: context is invalid");
return MRAA_ERROR_INVALID_HANDLE;
}
if (dev->bright_fd != -1) {
close(dev->bright_fd);
}
if (dev->trig_fd != -1) {
close(dev->trig_fd);
}
if (dev->max_bright_fd != -1) {
close(dev->max_bright_fd);
}
free(dev);
return MRAA_SUCCESS;
}

5
src/mraa.i
View File

@@ -13,6 +13,7 @@
#include "spi.hpp"
#include "aio.hpp"
#include "uart.hpp"
#include "led.hpp"
%}
%exception {
@@ -34,6 +35,7 @@
%template (spiFromDesc) mraa::initIo<mraa::Spi>;
%template (i2cFromDesc) mraa::initIo<mraa::I2c>;
%template (pwmFromDesc) mraa::initIo<mraa::Pwm>;
%template (ledFromDesc) mraa::initIo<mraa::Led>;
%ignore Aio(void* aio_context);
%ignore Pwm(void* pwm_context);
@@ -41,6 +43,7 @@
%ignore Spi(void* spi_context);
%ignore I2c(void* i2c_context);
%ignore Gpio(void* gpio_context);
%ignore Led(void* led_context);
%ignore Gpio::nop(uv_work_t* req);
%ignore Gpio::v8isr(uv_work_t* req);
@@ -59,3 +62,5 @@
%include "aio.hpp"
%include "uart.hpp"
%include "led.hpp"