File content as of revision 10:5b3be78ce6bd:

/***************************************************************************/
// DMA-enabled high data rate driver for Heroic Robotics FastPixel strips.
// Written by Jas Strong <jasmine@heroicrobotics.com>
// Copyright (c) 2013-2014 Heroic Robotics, Inc.
//
// FastPixel is a family of high performance LED strips available from
// Heroic Robotics, Inc.  http://heroicrobotics.com/ - check them out!
//
// These strips are capable of supporting 18 Mbit/sec when run on PixelPusher
// hardware;  your performance on mbed is likely to be somewhat lower due to
// the lack of high performance driver chips on the SPI lines.
//
// Heroic Robotics also sells a family of dedicated LED controllers called
// PixelPusher-  almost certainly the best LED controller in the world.
//
// 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.
//
//
// Some code originally from:
// Mbed library to control LPD8806-based RGB LED Strips
// (c) 2011 Jelmer Tiete
// That library is ported from the Arduino implementation of Adafruit Industries
// found at: http://github.com/adafruit/LPD8806
// and their strips: http://www.adafruit.com/products/306
// Released under the MIT License: http://mbed.org/license/mit
//
// Parameterized and modified to use soft SPI.
// Jas Strong <jasmine@electronpusher.org>
// Then remonstered to use hardware SPI for blast mode.
//
/*****************************************************************************/

#include "LedStrip.h"
#include "FastPixelLPD8806.h"

#include "MODDMA.h"

#define LATCHNUMBER 32
#define FAST_PIXEL_MHZ 18

// DMA controller and frequency setting
extern MODDMA dma;
extern int current_strip_fill;
 
 // when the transfer is complete, kill the channel.
void dma_complete_callback() {
    MODDMA_Config *config = dma.getConfig();
    dma.Disable( (MODDMA::CHANNELS)config->channelNum() );
    
    // clear the IRQ flags
    if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq();    
    if (dma.irqType() == MODDMA::ErrIrq) dma.clearErrIrq();  
}
 
void dma_err_callback() {
    MODDMA_Config *config = dma.getConfig();
    dma.Disable( (MODDMA::CHANNELS)config->channelNum() );
    
    // clear the IRQ flags
    if (dma.irqType() == MODDMA::TcIrq) dma.clearTcIrq();    
    if (dma.irqType() == MODDMA::ErrIrq) dma.clearErrIrq();  
} 

FastPixelLPD8806::FastPixelLPD8806(PinName dataPin, PinName clockPin, int n) :
    _spi(dataPin, NC, clockPin)
 {
    // Allocate 3 bytes per pixel plus latch bytes
    numLEDs = n;
    pixels = (uint8_t *)malloc(numLEDs * 3 + ((numLEDs + LATCHNUMBER-1) / LATCHNUMBER));
    if (pixels) {
        memset(pixels, 0x80, numLEDs * 3); // Init to RGB 'off' state
        memset(pixels+numLEDs*3, 0x0, (numLEDs + LATCHNUMBER-1) / LATCHNUMBER); // latch data
    }
        
    _spi.format(8,0);
    _spi.frequency(FAST_PIXEL_MHZ*1000000);
    
    // remember which strip we are
    strip_num = current_strip_fill;
    
    // make a new DMA config
    dma_config = new MODDMA_Config;
}
 
inline void FastPixelLPD8806::write(uint8_t byte) {
    _spi.write(byte);
}


void FastPixelLPD8806::begin(void) {

    blank();
    show();
    show();
}

uint16_t FastPixelLPD8806::numPixels(void) {
    return numLEDs;
}

void FastPixelLPD8806::blank(void) {
    memset(pixels, 0x80, numLEDs * 3);
}

// Set up the DMA controller;  we only have two SSP peripherals, so only two strips.

void FastPixelLPD8806::show(void) {
     if (strip_num == 0) {
        dma_config  -> channelNum   (MODDMA::Channel_0)
                    -> srcMemAddr   ( (uint32_t) pixels )
                    -> dstMemAddr   ( MODDMA::SSP0_Tx )
                    -> transferSize (numLEDs * 3 + ((numLEDs + LATCHNUMBER-1) / LATCHNUMBER))
                    -> transferType (MODDMA::m2p)
                    -> dstConn      (MODDMA::SSP0_Tx)
                    -> attach_tc    (&dma_complete_callback)
                    -> attach_err   (&dma_err_callback);
       LPC_SSP0->DMACR = (1<<1)|(1<<0); // TX,RXDMAE
    } else {
        dma_config  -> channelNum   (MODDMA::Channel_1)
                    -> srcMemAddr   ( (uint32_t) pixels )
                    -> dstMemAddr   ( MODDMA::SSP1_Tx )
                    -> transferSize (numLEDs * 3 + ((numLEDs +LATCHNUMBER-1) / LATCHNUMBER))
                    -> transferType (MODDMA::m2p)
                    -> dstConn      (MODDMA::SSP1_Tx)
                    -> attach_tc    (&dma_complete_callback)
                    -> attach_err   (&dma_err_callback);
       LPC_SSP1->DMACR = (1<<1)|(1<<0); // TX,RXDMAE
    }
    while (dma.Enabled(dma_config->channelNum())) {
        __nop();
    }
    dma.Setup(dma_config);
    dma.Enable(dma_config);
}

// LPD8806 is 7-bit, so we shift to normalize to 256 PWM steps.
uint32_t FastPixelLPD8806::total_luminance(void) {
    uint32_t running_total;
    running_total = 0;
    for (int i=0; i<numLEDs*3; i++)
        running_total += ((pixels[i] & 0x7f) <<1);
    return running_total;
}

// Convert R,G,B to combined 32-bit color
uint32_t FastPixelLPD8806::Color(uint8_t r, uint8_t g, uint8_t b) {
    // Take the lowest 7 bits of each value and append them end to end
    // We have the top bit set high (its a 'parity-like' bit in the protocol
    // and must be set!)
    return 0x808080 | ((uint32_t)(g>>1) << 16) | ((uint32_t)(r>>1) << 8) | (uint32_t)(b>>1);
}

// store the rgb component in our array
void FastPixelLPD8806::setPixelColor(uint16_t n, uint8_t r, uint8_t g, uint8_t b) {
    if (n >= numLEDs) return; // '>=' because arrays are 0-indexed

    pixels[n*3  ] = (g>>1) | 0x80;
    pixels[n*3+1] = (r>>1) | 0x80;
    pixels[n*3+2] = (b>>1) | 0x80;
}

void FastPixelLPD8806::setPixelR(uint16_t n, uint8_t r) {
    if (n >= numLEDs) return; // '>=' because arrays are 0-indexed

    pixels[n*3+1] = (r>>1) | 0x80;
}

void FastPixelLPD8806::setPixelG(uint16_t n, uint8_t g) {
    if (n >= numLEDs) return; // '>=' because arrays are 0-indexed

    pixels[n*3] = (g>>1) | 0x80;
}

void FastPixelLPD8806::setPixelB(uint16_t n, uint8_t b) {
    if (n >= numLEDs) return; // '>=' because arrays are 0-indexed

    pixels[n*3+2] = (b>>1) | 0x80;
}

// Set all in one function call, assuming GRB ordering
void FastPixelLPD8806::setPackedPixels(uint8_t * buffer, uint32_t n) {
    if (n >= numLEDs) return;
    for (int i=0; i<n*3; i++)
        buffer[i] = (buffer[i] >> 1) | 0x80;
    memcpy(pixels, buffer, (size_t) (n*3));
}

void FastPixelLPD8806::setPixelColor(uint16_t n, uint32_t c) {
    if (n >= numLEDs) return; // '>=' because arrays are 0-indexed

    pixels[n*3  ] = (c >> 16) | 0x80;
    pixels[n*3+1] = (c >>  8) | 0x80;
    pixels[n*3+2] =  c        | 0x80;
}