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neorv32/sw/lib/source/neorv32_neoled.c

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// #################################################################################################
// # << NEORV32: neorv32_neoled.c - Smart LED Interface (NEOLED) HW Driver >> #
// # ********************************************************************************************* #
// # BSD 3-Clause License #
// # #
// # Copyright (c) 2023, Stephan Nolting. All rights reserved. #
// # #
// # 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 of the copyright holder 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 HOLDER 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. #
// # ********************************************************************************************* #
// # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #
// #################################################################################################
/**********************************************************************//**
* @file neorv32_neoled.c
* @brief Smart LED Interface (NEOLED) HW driver source file.
*
* @note These functions should only be used if the NEOLED unit was synthesized (IO_NEOLED_EN = true).
**************************************************************************/
#include "neorv32.h"
#include "neorv32_neoled.h"
/**********************************************************************//**
* Check if NEOLED unit was synthesized.
*
* @return 0 if NEOLED was not synthesized, 1 if NEOLED is available.
**************************************************************************/
int neorv32_neoled_available(void) {
if (NEORV32_SYSINFO->SOC & (1 << SYSINFO_SOC_IO_NEOLED)) {
return 1;
}
else {
return 0;
}
}
/**********************************************************************//**
* Enable and configure NEOLED controller. The NEOLED control register bits are listed in #NEORV32_NEOLED_CTRL_enum.
* This function performs a "raw" configuration (just configuring the according control register bit).
*
* @param[in] prsc Clock prescaler select (0..7). See #NEORV32_CLOCK_PRSC_enum.
* @param[in] t_total Number of pre-scaled clock ticks for total bit period (0..31).
* @param[in] t_high_zero Number of pre-scaled clock ticks to generate high-time for sending a '0' (0..31).
* @param[in] t_high_one Number of pre-scaled clock ticks to generate high-time for sending a '1' (0..31).
* @param[in] irq_mode Interrupt condition (1=IRQ if FIFO is empty, 1=IRQ if FIFO is less than half-full).
**************************************************************************/
void neorv32_neoled_setup(uint32_t prsc, uint32_t t_total, uint32_t t_high_zero, uint32_t t_high_one, int irq_mode) {
NEORV32_NEOLED->CTRL = 0; // reset
uint32_t tmp = 0;
tmp |= (uint32_t)((1 & 0x01U) << NEOLED_CTRL_EN); // module enable
tmp |= (uint32_t)((prsc & 0x07U) << NEOLED_CTRL_PRSC0); // clock pre-scaler
tmp |= (uint32_t)((t_total & 0x1fU) << NEOLED_CTRL_T_TOT_0); // serial data output: total period length for one bit
tmp |= (uint32_t)((t_high_zero & 0x1fU) << NEOLED_CTRL_T_ZERO_H_0); // serial data output: high-time for sending a '0'
tmp |= (uint32_t)((t_high_one & 0x1fU) << NEOLED_CTRL_T_ONE_H_0); // serial data output: high-time for sending a '1'
tmp |= (uint32_t)((irq_mode & 0x01U) << NEOLED_CTRL_EN); // interrupt mode
NEORV32_NEOLED->CTRL = tmp;
}
/**********************************************************************//**
* Configure NEOLED controller for using WS2812 LEDs (NeoPixel-compatible). This function computes
* all the required timings and finally calls #neorv32_neoled_setup.
*
* @note WS2812 timing: T_period = 1.2us, T_high_zero = 0.4us, T_high_one = 0.8us. Change the constants if required.
* @note This function uses the SYSINFO_CLK value (from the SYSINFO HW module) to do the timing computations.
*
* @param[in] irq_mode Interrupt condition (1=IRQ if FIFO is empty, 1=IRQ if FIFO is less than half-full).
**************************************************************************/
void neorv32_neoled_setup_ws2812(int irq_mode) {
// WS2812 timing
const uint32_t T_TOTAL_C = 1200; // ns
const uint32_t T_H_ZERO_C = 400; // ns
const uint32_t T_H_ONE_C = 800; // ns
// processor clock pre-scalers
const uint16_t CLK_PRSC_FACTOR_LUT[8] = {2, 4, 8, 64, 128, 1024, 2048, 4096};
// get base clock period in multiples of 0.5ns
uint32_t t_clock_x500ps = (2 * 1000 * 1000 * 1000) / NEORV32_SYSINFO->CLK;
// compute LED interface timing parameters
uint32_t t_base = 0;
uint32_t t_total = 0;
uint32_t t_high_zero = 0;
uint32_t t_high_one = 0;
uint32_t clk_prsc_sel = CLK_PRSC_2; // initial prsc = CLK/2
uint32_t clk_prsc_fac = 0; // corresponding clock scaling factor
//neorv32_uart0_printf("\nNEOLED.T_clk: %u x 500ps\n", t_clock_x500ps); // DEBUG
while (clk_prsc_sel < 7) {
clk_prsc_fac = (uint32_t)CLK_PRSC_FACTOR_LUT[clk_prsc_sel & 7];
//neorv32_uart0_printf("NEOLED.clk_prsc: %u\n", clk_prsc_fac); // DEBUG
t_base = t_clock_x500ps * clk_prsc_fac;
//neorv32_uart0_printf("NEOLED.t_base: %u x 0.5ns\n", t_base); // DEBUG
// compute bit period and high-times for sending a 0 or 1
t_total = (2*T_TOTAL_C) / t_base;
t_high_zero = (2*T_H_ZERO_C) / t_base;
t_high_one = (2*T_H_ONE_C) / t_base;
//neorv32_uart0_printf("NEOLED.t_total: %u\n", t_total); // DEBUG
//neorv32_uart0_printf("NEOLED.t_high_zero: %u\n", t_high_zero); // DEBUG
//neorv32_uart0_printf("NEOLED.t_high_one: %u\n", t_high_one); // DEBUG
if ((t_base == 0) || (t_total >= 32) || (t_high_zero == 0) || (t_high_one == 0)) { // out of range or invalid resolution
clk_prsc_sel++; // try next-higher clock prescaler
}
else {
break;
}
}
// set raw configuration
neorv32_neoled_setup(clk_prsc_sel, t_total, t_high_zero, t_high_one, irq_mode);
}
/**********************************************************************//**
* Set NEOLED mode (24-bit RGB / 32-bit RGBW).
*
* @param[in] mode 0 = 24-bit mode (RGB), 1 = 32-bit mode (RGBW)
**************************************************************************/
void neorv32_neoled_set_mode(uint32_t mode) {
uint32_t ctrl = NEORV32_NEOLED->CTRL;
ctrl &= ~(0b1 << NEOLED_CTRL_MODE); // clear current mode
ctrl |= ((mode & 1) << NEOLED_CTRL_MODE); // set new mode
NEORV32_NEOLED->CTRL = ctrl;
}
/**********************************************************************//**
* Send strobe command ("RESET") - blocking.
**************************************************************************/
void neorv32_neoled_strobe_blocking(void) {
while(1) { // wait for FIFO full flag to clear
if ((NEORV32_NEOLED->CTRL & (1 << NEOLED_CTRL_TX_FULL)) == 0) {
break;
}
}
neorv32_neoled_strobe_nonblocking();
}
/**********************************************************************//**
* Send strobe command ("RESET") - non-blocking.
**************************************************************************/
void neorv32_neoled_strobe_nonblocking(void) {
const uint32_t mask = 1 << NEOLED_CTRL_STROBE; // strobe bit
uint32_t ctrl = NEORV32_NEOLED->CTRL;
NEORV32_NEOLED->CTRL = ctrl | mask; // set strobe bit
NEORV32_NEOLED->DATA = 0; // send any data to trigger strobe command
NEORV32_NEOLED->CTRL = ctrl & (~mask); // clear strobe bit
}
/**********************************************************************//**
* Enable NEOLED controller.
**************************************************************************/
void neorv32_neoled_enable(void) {
NEORV32_NEOLED->CTRL |= ((uint32_t)(1 << NEOLED_CTRL_EN));
}
/**********************************************************************//**
* Disable NEOLED controller.
**************************************************************************/
void neorv32_neoled_disable(void) {
NEORV32_NEOLED->CTRL &= ~((uint32_t)(1 << NEOLED_CTRL_EN));
}
/**********************************************************************//**
* Send single RGB(W) data word to NEOLED module (blocking).
*
* @warning This function is blocking as it polls the NEOLED FIFO full flag.
*
* @param[in] data LSB-aligned 24-bit RGB or 32-bit RGBW data
**************************************************************************/
void neorv32_neoled_write_blocking(uint32_t data) {
while(1) { // wait for FIFO full flag to clear
if ((NEORV32_NEOLED->CTRL & (1 << NEOLED_CTRL_TX_FULL)) == 0) {
break;
}
}
neorv32_neoled_write_nonblocking(data); // send new LED data
}
/**********************************************************************//**
* Get NEOLED hardware buffer size.
*
* @return Number of entries in NEOLED TX buffer.
**************************************************************************/
uint32_t neorv32_neoled_get_buffer_size(void) {
uint32_t tmp = NEORV32_NEOLED->CTRL;
tmp = tmp >> NEOLED_CTRL_BUFS_0;
tmp = tmp & 0xf; // isolate buffer size bits
return (1 << tmp); // num entries = pow(2, buffer size flags)
}
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