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RIOT/drivers/my9221/my9221.c

138 lines
3.1 KiB
C

/*
* Copyright (C) 2017 HAW Hamburg
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup drivers_my9221
*
* @{
* @file
* @brief Driver for the MY9221 LED controller
*
* @author Sebastian Meiling <s@mlng.net>
*
* @}
*/
#include <assert.h>
#include <stdint.h>
#include <string.h>
#include "log.h"
#include "periph/gpio.h"
#include "xtimer.h"
#include "my9221.h"
#include "my9221_internal.h"
#define DEV_DIR (dev->params.dir)
#define DEV_LEDS (dev->params.leds)
#define DEV_STATE(x) (dev->state[x])
#define PIN_CLK (dev->params.clk)
#define PIN_DAT (dev->params.dat)
/**
* @brief Write a single data to the LED controller
*/
static void _write(my9221_t *dev, uint16_t data)
{
assert(dev);
for (unsigned i = 0; i < 16; ++i) {
(data & 0x8000) ? gpio_set(PIN_DAT) : gpio_clear(PIN_DAT);
gpio_toggle(PIN_CLK);
data <<= 1;
}
}
/**
* @brief Load data into the latch register of the LED controller
*/
static void _latch(my9221_t *dev)
{
assert(dev);
gpio_clear(PIN_DAT);
xtimer_usleep(MY9221_LATCH_WAIT);
for (unsigned i = 0; i < MY9221_LATCH_LOOP; ++i) {
gpio_set(PIN_DAT);
gpio_clear(PIN_DAT);
}
}
/**
* @brief Write state data of all LEDs to the controller
*/
static void _set_state(my9221_t *dev)
{
assert(dev);
_write(dev, MY9221_CMDMODE);
for (unsigned i = 0; i < DEV_LEDS; ++i) {
if (DEV_DIR == MY9221_DIR_REV) {
/* Write LED state in reverse order */
_write(dev, DEV_STATE(DEV_LEDS-i-1));
}
else {
/* Write LED state in forward order */
_write(dev, DEV_STATE(i));
}
}
/* set unused LED pins to off */
for (unsigned j = DEV_LEDS; j < MY9221_LED_MAX; ++j) {
_write(dev, MY9221_LED_OFF);
}
_latch(dev);
}
int my9221_init(my9221_t *dev, const my9221_params_t *params)
{
assert(dev);
assert(params);
/* write config params to device descriptor */
dev->params = *params;
/* init clock and data pins as output */
gpio_init(PIN_CLK, GPIO_OUT);
gpio_init(PIN_DAT, GPIO_OUT);
/* reset state, i.e., all LEDs off */
memset(dev->state, 0, sizeof(dev->state));
_set_state(dev);
return MY9221_OK;
}
void my9221_set_state(my9221_t *dev, const uint8_t *state, uint8_t len)
{
if ((state != NULL) && (len > 0)) {
if (len > MY9221_LED_MAX) {
len = MY9221_LED_MAX;
}
memcpy(dev->state, state, len);
}
_set_state(dev);
}
void my9221_set_led(my9221_t *dev, const uint8_t led, const uint8_t alpha)
{
assert(dev);
assert(led < DEV_LEDS);
DEV_STATE(led) = ~(MY9221_LED_ON << ((uint16_t)(alpha << 3) >> 8));
_set_state(dev);
}
void my9221_toggle_led(my9221_t *dev, const uint8_t led)
{
assert(dev);
assert(led < DEV_LEDS);
DEV_STATE(led) = DEV_STATE(led) ? MY9221_LED_OFF : MY9221_LED_ON;
_set_state(dev);
}