390 lines
13 KiB
C
390 lines
13 KiB
C
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// Raspberry Pi WS2812 LED driver using SMI
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// For detailed description, see https://iosoft.blog
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//
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// Copyright (c) 2020 Jeremy P Bentham
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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// v0.01 JPB 16/7/20 Adapted from rpi_smi_adc_test v0.06
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// v0.02 JPB 15/9/20 Addded RGB to GRB conversion
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// v0.03 JPB 15/9/20 Added red-green flashing
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// v0.04 JPB 16/9/20 Added test mode
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// v0.05 JPB 19/9/20 Changed test mode colours
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// v0.06 JPB 20/9/20 Outlined command-line data input
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// v0.07 JPB 25/9/20 Command-line data input if not in test mode
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// v0.08 JPB 26/9/20 Changed from 4 to 3 pulses per LED bit
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// Added 4-bit zero preamble
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// Added raw Tx data test
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// v0.09 JPB 27/9/20 Added 16-channel option
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// v0.10 JPB 28/9/20 Corrected Pi Zero caching problem
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// v0.11 JPB 29/9/20 Added enable_dma before transfer (in case still active)
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// Corrected DMA nsamp value (was byte count)
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#include <stdio.h>
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#include <signal.h>
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#include <stdint.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <ctype.h>
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#include "rpi_dma_utils.h"
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#include "rpi_smi_defs.h"
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#if PHYS_REG_BASE==PI_4_REG_BASE // Timings for RPi v4 (1.5 GHz)
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#define SMI_TIMING 10, 15, 30, 15 // 400 ns cycle time
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#else // Timings for RPi v0-3 (1 GHz)
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#define SMI_TIMING 10, 10, 20, 10 // 400 ns cycle time
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#endif
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#define TX_TEST 0 // If non-zero, use dummy Tx data
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#define LED_D0_PIN 8 // GPIO pin for D0 output
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#define LED_NCHANS 8 // Number of LED channels (8 or 16)
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#define LED_NBITS 24 // Number of data bits per LED
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#define LED_PREBITS 4 // Number of zero bits before LED data
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#define LED_POSTBITS 4 // Number of zero bits after LED data
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#define BIT_NPULSES 3 // Number of O/P pulses per LED bit
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#define CHAN_MAXLEDS 50 // Maximum number of LEDs per channel
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#define CHASE_MSEC 100 // Delay time for chaser light test
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#define REQUEST_THRESH 2 // DMA request threshold
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#define DMA_CHAN 10 // DMA channel to use
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// Length of data for 1 row (1 LED on each channel)
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#define LED_DLEN (LED_NBITS * BIT_NPULSES)
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// Transmit data type, 8 or 16 bits
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#if LED_NCHANS > 8
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#define TXDATA_T uint16_t
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#else
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#define TXDATA_T uint8_t
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#endif
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// Structures for mapped I/O devices, and non-volatile memory
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extern MEM_MAP gpio_regs, dma_regs;
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MEM_MAP vc_mem, clk_regs, smi_regs;
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// Pointers to SMI registers
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volatile SMI_CS_REG *smi_cs;
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volatile SMI_L_REG *smi_l;
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volatile SMI_A_REG *smi_a;
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volatile SMI_D_REG *smi_d;
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volatile SMI_DMC_REG *smi_dmc;
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volatile SMI_DSR_REG *smi_dsr;
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volatile SMI_DSW_REG *smi_dsw;
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volatile SMI_DCS_REG *smi_dcs;
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volatile SMI_DCA_REG *smi_dca;
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volatile SMI_DCD_REG *smi_dcd;
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// Ofset into Tx data buffer, given LED number in chan
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#define LED_TX_OSET(n) (LED_PREBITS + (LED_DLEN * (n)))
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// Size of data buffers & NV memory, given number of LEDs per chan
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#define TX_BUFF_LEN(n) (LED_TX_OSET(n) + LED_POSTBITS)
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#define TX_BUFF_SIZE(n) (TX_BUFF_LEN(n) * sizeof(TXDATA_T))
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#define VC_MEM_SIZE (PAGE_SIZE + TX_BUFF_SIZE(CHAN_MAXLEDS))
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// RGB values for test mode (1 value for each of 16 channels)
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int on_rgbs[16] = {0xff0000, 0x00ff00, 0x0000ff, 0xffffff,
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0xff4040, 0x40ff40, 0x4040ff, 0x404040,
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0xff0000, 0x00ff00, 0x0000ff, 0xffffff,
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0xff4040, 0x40ff40, 0x4040ff, 0x404040};
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int off_rgbs[16];
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#if TX_TEST
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// Data for simple transmission test
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TXDATA_T tx_test_data[] = {1, 2, 3, 4, 5, 6, 7, 0};
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#endif
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TXDATA_T *txdata; // Pointer to uncached Tx data buffer
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TXDATA_T tx_buffer[TX_BUFF_LEN(CHAN_MAXLEDS)]; // Tx buffer for assembling data
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int testmode, chan_ledcount=1; // Command-line parameters
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int rgb_data[CHAN_MAXLEDS][LED_NCHANS]; // RGB data
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int chan_num; // Current channel for data I/P
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void rgb_txdata(int *rgbs, TXDATA_T *txd);
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int str_rgb(char *s, int rgbs[][LED_NCHANS], int chan);
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void swap_bytes(void *data, int len);
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int hexdig(char c);
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void map_devices(void);
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void fail(char *s);
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void terminate(int sig);
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void init_smi(int width, int ns, int setup, int hold, int strobe);
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void setup_smi_dma(MEM_MAP *mp, int nsamp);
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void start_smi(MEM_MAP *mp);
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int main(int argc, char *argv[])
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{
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int args=0, n, oset=0;
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while (argc > ++args) // Process command-line args
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{
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if (argv[args][0] == '-')
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{
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switch (toupper(argv[args][1]))
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{
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case 'N': // -N: number of LEDs per channel
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if (args >= argc-1)
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fprintf(stderr, "Error: no numeric value\n");
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else
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chan_ledcount = atoi(argv[++args]);
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break;
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case 'T': // -T: test mode
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testmode = 1;
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break;
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default: // Otherwise error
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printf("Unrecognised option '%c'\n", argv[args][1]);
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printf("Options:\n"
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" -n num number of LEDs per channel\n"\
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" -t Test mode (flash LEDs)\n"\
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);
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return(1);
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}
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}
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else if (chan_num<LED_NCHANS && hexdig(argv[args][0])>=0 &&
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(n=str_rgb(argv[args], rgb_data, chan_num))>0)
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{
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chan_ledcount = n > chan_ledcount ? n : chan_ledcount;
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chan_num++;
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}
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}
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signal(SIGINT, terminate);
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map_devices();
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init_smi(LED_NCHANS>8 ? SMI_16_BITS : SMI_8_BITS, SMI_TIMING);
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map_uncached_mem(&vc_mem, VC_MEM_SIZE);
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#if TX_TEST
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oset = oset;
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setup_smi_dma(&vc_mem, sizeof(tx_test_data)/sizeof(TXDATA_T));
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#if LED_NCHANS <= 8
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swap_bytes(tx_test_data, sizeof(tx_test_data));
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#endif
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memcpy(txdata, tx_test_data, sizeof(tx_test_data));
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start_smi(&vc_mem);
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usleep(10);
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while (dma_active(DMA_CHAN))
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usleep(10);
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#else
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setup_smi_dma(&vc_mem, TX_BUFF_LEN(chan_ledcount));
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printf("%s %u LED%s per channel, %u channels\n", testmode ? "Testing" : "Setting",
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chan_ledcount, chan_ledcount==1 ? "" : "s", LED_NCHANS);
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if (testmode)
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{
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while (1)
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{
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if (chan_ledcount < 2)
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rgb_txdata(oset&1 ? off_rgbs : on_rgbs, tx_buffer);
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else
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{
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for (n=0; n<chan_ledcount; n++)
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{
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rgb_txdata(n==oset%chan_ledcount ? on_rgbs : off_rgbs,
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&tx_buffer[LED_TX_OSET(n)]);
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}
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}
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oset++;
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#if LED_NCHANS <= 8
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swap_bytes(tx_buffer, TX_BUFF_SIZE(chan_ledcount));
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#endif
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memcpy(txdata, tx_buffer, TX_BUFF_SIZE(chan_ledcount));
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start_smi(&vc_mem);
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usleep(CHASE_MSEC * 1000);
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}
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}
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else
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{
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for (n=0; n<chan_ledcount; n++)
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rgb_txdata(rgb_data[n], &tx_buffer[LED_TX_OSET(n)]);
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#if LED_NCHANS <= 8
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swap_bytes(tx_buffer, TX_BUFF_SIZE(chan_ledcount));
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#endif
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memcpy(txdata, tx_buffer, TX_BUFF_SIZE(chan_ledcount));
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enable_dma(DMA_CHAN);
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start_smi(&vc_mem);
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usleep(10);
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while (dma_active(DMA_CHAN))
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usleep(10);
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}
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#endif
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terminate(0);
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return(0);
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}
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// Convert RGB text string into integer data, for given channel
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// Return number of data points for this channel
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int str_rgb(char *s, int rgbs[][LED_NCHANS], int chan)
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{
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int i=0;
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char *p;
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while (chan<LED_NCHANS && i<CHAN_MAXLEDS && hexdig(*s)>=0)
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{
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rgbs[i++][chan] = strtoul(s, &p, 16);
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s = *p ? p+1 : p;
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}
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return(i);
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}
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// Set Tx data for 8 or 16 chans, 1 LED per chan, given 1 RGB val per chan
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// Logic 1 is 0.8us high, 0.4 us low, logic 0 is 0.4us high, 0.8us low
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void rgb_txdata(int *rgbs, TXDATA_T *txd)
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{
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int i, n, msk;
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// For each bit of the 24-bit RGB values..
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for (n=0; n<LED_NBITS; n++)
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{
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// Mask to convert RGB to GRB, M.S bit first
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msk = n==0 ? 0x8000 : n==8 ? 0x800000 : n==16 ? 0x80 : msk>>1;
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// 1st byte or word is a high pulse on all lines
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txd[0] = (TXDATA_T)0xffff;
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// 2nd has high or low bits from data
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// 3rd is a low pulse
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txd[1] = txd[2] = 0;
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for (i=0; i<LED_NCHANS; i++)
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{
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if (rgbs[i] & msk)
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txd[1] |= (1 << i);
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}
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txd += BIT_NPULSES;
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}
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}
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// Swap adjacent bytes in transmit data
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void swap_bytes(void *data, int len)
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{
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uint16_t *wp = (uint16_t *)data;
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len = (len + 1) / 2;
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while (len-- > 0)
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{
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*wp = __builtin_bswap16(*wp);
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wp++;
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}
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}
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// Return hex digit value, -ve if not hex
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int hexdig(char c)
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{
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c = toupper(c);
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return((c>='0' && c<='9') ? c-'0' : (c>='A' && c<='F') ? c-'A'+10 : -1);
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}
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// Map GPIO, DMA and SMI registers into virtual mem (user space)
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// If any of these fail, program will be terminated
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void map_devices(void)
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{
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map_periph(&gpio_regs, (void *)GPIO_BASE, PAGE_SIZE);
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map_periph(&dma_regs, (void *)DMA_BASE, PAGE_SIZE);
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map_periph(&clk_regs, (void *)CLK_BASE, PAGE_SIZE);
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map_periph(&smi_regs, (void *)SMI_BASE, PAGE_SIZE);
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}
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// Catastrophic failure in initial setup
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void fail(char *s)
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{
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printf(s);
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terminate(0);
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}
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// Free memory segments and exit
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void terminate(int sig)
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{
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int i;
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printf("Closing\n");
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if (gpio_regs.virt)
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{
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for (i=0; i<LED_NCHANS; i++)
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gpio_mode(LED_D0_PIN+i, GPIO_IN);
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}
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if (smi_regs.virt)
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*REG32(smi_regs, SMI_CS) = 0;
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stop_dma(DMA_CHAN);
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unmap_periph_mem(&vc_mem);
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unmap_periph_mem(&smi_regs);
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unmap_periph_mem(&dma_regs);
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unmap_periph_mem(&gpio_regs);
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exit(0);
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}
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// Initialise SMI, given data width, time step, and setup/hold/strobe counts
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// Step value is in nanoseconds: even numbers, 2 to 30
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void init_smi(int width, int ns, int setup, int strobe, int hold)
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{
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int i, divi = ns / 2;
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smi_cs = (SMI_CS_REG *) REG32(smi_regs, SMI_CS);
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smi_l = (SMI_L_REG *) REG32(smi_regs, SMI_L);
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smi_a = (SMI_A_REG *) REG32(smi_regs, SMI_A);
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smi_d = (SMI_D_REG *) REG32(smi_regs, SMI_D);
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smi_dmc = (SMI_DMC_REG *)REG32(smi_regs, SMI_DMC);
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smi_dsr = (SMI_DSR_REG *)REG32(smi_regs, SMI_DSR0);
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smi_dsw = (SMI_DSW_REG *)REG32(smi_regs, SMI_DSW0);
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smi_dcs = (SMI_DCS_REG *)REG32(smi_regs, SMI_DCS);
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smi_dca = (SMI_DCA_REG *)REG32(smi_regs, SMI_DCA);
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smi_dcd = (SMI_DCD_REG *)REG32(smi_regs, SMI_DCD);
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smi_cs->value = smi_l->value = smi_a->value = 0;
|
||
|
|
smi_dsr->value = smi_dsw->value = smi_dcs->value = smi_dca->value = 0;
|
||
|
|
if (*REG32(clk_regs, CLK_SMI_DIV) != divi << 12)
|
||
|
|
{
|
||
|
|
*REG32(clk_regs, CLK_SMI_CTL) = CLK_PASSWD | (1 << 5);
|
||
|
|
usleep(10);
|
||
|
|
while (*REG32(clk_regs, CLK_SMI_CTL) & (1 << 7)) ;
|
||
|
|
usleep(10);
|
||
|
|
*REG32(clk_regs, CLK_SMI_DIV) = CLK_PASSWD | (divi << 12);
|
||
|
|
usleep(10);
|
||
|
|
*REG32(clk_regs, CLK_SMI_CTL) = CLK_PASSWD | 6 | (1 << 4);
|
||
|
|
usleep(10);
|
||
|
|
while ((*REG32(clk_regs, CLK_SMI_CTL) & (1 << 7)) == 0) ;
|
||
|
|
usleep(100);
|
||
|
|
}
|
||
|
|
if (smi_cs->seterr)
|
||
|
|
smi_cs->seterr = 1;
|
||
|
|
smi_dsr->rsetup = smi_dsw->wsetup = setup;
|
||
|
|
smi_dsr->rstrobe = smi_dsw->wstrobe = strobe;
|
||
|
|
smi_dsr->rhold = smi_dsw->whold = hold;
|
||
|
|
smi_dmc->panicr = smi_dmc->panicw = 8;
|
||
|
|
smi_dmc->reqr = smi_dmc->reqw = REQUEST_THRESH;
|
||
|
|
smi_dsr->rwidth = smi_dsw->wwidth = width;
|
||
|
|
for (i=0; i<LED_NCHANS; i++)
|
||
|
|
gpio_mode(LED_D0_PIN+i, GPIO_ALT1);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Set up SMI transfers using DMA
|
||
|
|
void setup_smi_dma(MEM_MAP *mp, int nsamp)
|
||
|
|
{
|
||
|
|
DMA_CB *cbs=mp->virt;
|
||
|
|
|
||
|
|
txdata = (TXDATA_T *)(cbs+1);
|
||
|
|
smi_dmc->dmaen = 1;
|
||
|
|
smi_cs->enable = 1;
|
||
|
|
smi_cs->clear = 1;
|
||
|
|
smi_cs->pxldat = 1;
|
||
|
|
smi_l->len = nsamp * sizeof(TXDATA_T);
|
||
|
|
smi_cs->write = 1;
|
||
|
|
enable_dma(DMA_CHAN);
|
||
|
|
cbs[0].ti = DMA_DEST_DREQ | (DMA_SMI_DREQ << 16) | DMA_CB_SRCE_INC | DMA_WAIT_RESP;
|
||
|
|
cbs[0].tfr_len = nsamp;
|
||
|
|
cbs[0].srce_ad = MEM_BUS_ADDR(mp, txdata);
|
||
|
|
cbs[0].dest_ad = REG_BUS_ADDR(smi_regs, SMI_D);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Start SMI DMA transfers
|
||
|
|
void start_smi(MEM_MAP *mp)
|
||
|
|
{
|
||
|
|
DMA_CB *cbs=mp->virt;
|
||
|
|
|
||
|
|
start_dma(mp, DMA_CHAN, &cbs[0], 0);
|
||
|
|
smi_cs->start = 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
// EOF
|