/****************************************************************************
* drivers/rgbled.c
*
* Copyright (C) 2016 Gregory Nutt. All rights reserved.
* Author: Alan Carvalho de Assis <acassis@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <semaphore.h>
#include <fcntl.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>
#include <nuttx/arch.h>
#include <nuttx/drivers/pwm.h>
#include <nuttx/leds/rgbled.h>
#include <arch/irq.h>
#ifdef CONFIG_RGBLED
/****************************************************************************
* Private Type Definitions
****************************************************************************/
/* This structure describes the state of the upper half driver */
struct rgbled_upperhalf_s
{
uint8_t crefs; /* The number of times the device has been opened */
volatile bool started; /* True: pulsed output is being generated */
sem_t exclsem; /* Supports mutual exclusion */
struct pwm_info_s ledr; /* Pulsed output for LED R*/
struct pwm_info_s ledg; /* Pulsed output for LED G*/
struct pwm_info_s ledb; /* Pulsed output for LED B*/
struct pwm_lowerhalf_s *devledr;
struct pwm_lowerhalf_s *devledg;
struct pwm_lowerhalf_s *devledb;
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int rgbled_open(FAR struct file *filep);
static int rgbled_close(FAR struct file *filep);
static ssize_t rgbled_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static ssize_t rgbled_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct file_operations g_rgbledops =
{
rgbled_open, /* open */
rgbled_close, /* close */
rgbled_read, /* read */
rgbled_write, /* write */
0, /* seek */
0 /* ioctl */
#ifndef CONFIG_DISABLE_POLL
, 0 /* poll */
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: rgbled_open
*
* Description:
* This function is called whenever the PWM device is opened.
*
****************************************************************************/
static int rgbled_open(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct rgbled_upperhalf_s *upper = inode->i_private;
uint8_t tmp;
int ret;
lcdinfo("crefs: %d\n", upper->crefs);
/* Get exclusive access to the device structures */
ret = sem_wait(&upper->exclsem);
if (ret < 0)
{
ret = -get_errno();
goto errout;
}
/* Increment the count of references to the device. If this the first
* time that the driver has been opened for this device, then initialize
* the device.
*/
tmp = upper->crefs + 1;
if (tmp == 0)
{
/* More than 255 opens; uint8_t overflows to zero */
ret = -EMFILE;
goto errout_with_sem;
}
/* Save the new open count on success */
upper->crefs = tmp;
ret = OK;
errout_with_sem:
sem_post(&upper->exclsem);
errout:
return ret;
}
/****************************************************************************
* Name: rgbled_close
*
* Description:
* This function is called when the PWM device is closed.
*
****************************************************************************/
static int rgbled_close(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct rgbled_upperhalf_s *upper = inode->i_private;
int ret;
lcdinfo("crefs: %d\n", upper->crefs);
/* Get exclusive access to the device structures */
ret = sem_wait(&upper->exclsem);
if (ret < 0)
{
ret = -get_errno();
goto errout;
}
/* Decrement the references to the driver. If the reference count will
* decrement to 0, then uninitialize the driver.
*/
if (upper->crefs > 1)
{
upper->crefs--;
}
sem_post(&upper->exclsem);
ret = OK;
errout:
return ret;
}
/****************************************************************************
* Name: rgbled_read
*
* Description:
* A dummy read method. This is provided only to satisfy the VFS layer.
*
****************************************************************************/
static ssize_t rgbled_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
/* Return zero -- usually meaning end-of-file */
return 0;
}
/****************************************************************************
* Name: rgbled_write
*
* Description:
* A dummy write method. This is provided only to satisfy the VFS layer.
*
****************************************************************************/
static ssize_t rgbled_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen)
{
FAR struct inode *inode = filep->f_inode;
FAR struct rgbled_upperhalf_s *upper = inode->i_private;
FAR struct pwm_lowerhalf_s *ledr = upper->devledr;
FAR struct pwm_lowerhalf_s *ledg = upper->devledg;
FAR struct pwm_lowerhalf_s *ledb = upper->devledb;
unsigned int red;
unsigned int green;
unsigned int blue;
char color[3];
/* We need to receive a string #RRGGBB = 7 bytes */
if (buffer == NULL || buflen < 7)
{
/* Well... nothing to do */
return -EINVAL;
}
/* Check if it is a color format */
if (buffer[0] != '#')
{
/* The color code needs to start with # */
return -EINVAL;
}
/* Move buffer to next character */
buffer++;
color[0] = buffer[0];
color[1] = buffer[1];
color[2] = '\0';
red = strtol(color, NULL, 16);
color[0] = buffer[2];
color[1] = buffer[3];
color[2] = '\0';
green = strtol(color, NULL, 16);
color[0] = buffer[4];
color[1] = buffer[5];
color[2] = '\0';
blue = strtol(color, NULL, 16);
/* Sane check */
if (red > 255)
{
red = 255;
}
if (green > 255)
{
green = 255;
}
if (blue > 255)
{
blue = 255;
}
/* Convert 8bit to 16bits */
red <<= 8;
green <<= 8;
blue <<= 8;
/* Setup LED R */
upper->ledr.frequency = 100;
upper->ledr.duty = red;
ledr->ops->start(ledr, &upper->ledr);
/* Setup LED G */
upper->ledg.frequency = 100;
upper->ledg.duty = green;
ledg->ops->start(ledg, &upper->ledg);
/* Setup LED B */
upper->ledb.frequency = 100;
upper->ledb.duty = blue;
ledb->ops->start(ledb, &upper->ledb);
return buflen;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: rgbled_register
*
* Description:
* This function binds three instances of a "lower half" PWM driver with
* the "upper half" RGB LED device and registers that device so that can
* be used by application code.
*
*
* Input parameters:
* path - The full path to the driver to be registers in the NuttX pseudo-
* filesystem. The recommended convention is to name all PWM drivers
* as "/dev/rgdbled0", "/dev/rgbled1", etc. where the driver path
* differs only in the "minor" number at the end of the device name.
* ledr, ledg, and ledb - A pointer to an instance of lower half PWM
* drivers for the red, green, and blue LEDs, respectively. These
* instances will be bound to the RGB LED driver and must persists as
* long as that driver persists.
*
* Returned Value:
* Zero on success; a negated errno value on failure.
*
****************************************************************************/
int rgbled_register(FAR const char *path, FAR struct pwm_lowerhalf_s *ledr,
FAR struct pwm_lowerhalf_s *ledg,
FAR struct pwm_lowerhalf_s *ledb)
{
FAR struct rgbled_upperhalf_s *upper;
/* Allocate the upper-half data structure */
upper = (FAR struct rgbled_upperhalf_s *)
kmm_zalloc(sizeof(struct rgbled_upperhalf_s));
if (!upper)
{
lcderr("ERROR: Allocation failed\n");
return -ENOMEM;
}
/* Initialize the PWM device structure (it was already zeroed by
* kmm_zalloc())
*/
sem_init(&upper->exclsem, 0, 1);
upper->devledr = ledr;
upper->devledg = ledg;
upper->devledb = ledb;
/* Register the PWM device */
lcdinfo("Registering %s\n", path);
return register_driver(path, &g_rgbledops, 0666, upper);
}
#endif /* CONFIG_RGBLED */