#include <AP_HAL/AP_HAL.h>
#if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_NAVIO
#include "GPIO.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdint.h>
#include <sys/ioctl.h>
#include <pthread.h>
#include <string.h>
#include <errno.h>
#include <stdint.h>
#include <time.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <assert.h>
#include "RCInput_Navio.h"
//Parametres
#define RCIN_NAVIO_BUFFER_LENGTH 8
#define RCIN_NAVIO_SAMPLE_FREQ 500
#define RCIN_NAVIO_DMA_CHANNEL 0
#define RCIN_NAVIO_MAX_COUNTER 1300
#define PPM_INPUT_NAVIO RPI_GPIO_4
#define RCIN_NAVIO_MAX_SIZE_LINE 50
//Memory Addresses
#define RCIN_NAVIO_RPI1_DMA_BASE 0x20007000
#define RCIN_NAVIO_RPI1_CLK_BASE 0x20101000
#define RCIN_NAVIO_RPI1_PCM_BASE 0x20203000
#define RCIN_NAVIO_RPI2_DMA_BASE 0x3F007000
#define RCIN_NAVIO_RPI2_CLK_BASE 0x3F101000
#define RCIN_NAVIO_RPI2_PCM_BASE 0x3F203000
#define RCIN_NAVIO_GPIO_LEV0_ADDR 0x7e200034
#define RCIN_NAVIO_DMA_LEN 0x1000
#define RCIN_NAVIO_CLK_LEN 0xA8
#define RCIN_NAVIO_PCM_LEN 0x24
#define RCIN_NAVIO_TIMER_BASE 0x7e003004
#define RCIN_NAVIO_DMA_SRC_INC (1<<8)
#define RCIN_NAVIO_DMA_DEST_INC (1<<4)
#define RCIN_NAVIO_DMA_NO_WIDE_BURSTS (1<<26)
#define RCIN_NAVIO_DMA_WAIT_RESP (1<<3)
#define RCIN_NAVIO_DMA_D_DREQ (1<<6)
#define RCIN_NAVIO_DMA_PER_MAP(x) ((x)<<16)
#define RCIN_NAVIO_DMA_END (1<<1)
#define RCIN_NAVIO_DMA_RESET (1<<31)
#define RCIN_NAVIO_DMA_INT (1<<2)
#define RCIN_NAVIO_DMA_CS (0x00/4)
#define RCIN_NAVIO_DMA_CONBLK_AD (0x04/4)
#define RCIN_NAVIO_DMA_DEBUG (0x20/4)
#define RCIN_NAVIO_PCM_CS_A (0x00/4)
#define RCIN_NAVIO_PCM_FIFO_A (0x04/4)
#define RCIN_NAVIO_PCM_MODE_A (0x08/4)
#define RCIN_NAVIO_PCM_RXC_A (0x0c/4)
#define RCIN_NAVIO_PCM_TXC_A (0x10/4)
#define RCIN_NAVIO_PCM_DREQ_A (0x14/4)
#define RCIN_NAVIO_PCM_INTEN_A (0x18/4)
#define RCIN_NAVIO_PCM_INT_STC_A (0x1c/4)
#define RCIN_NAVIO_PCM_GRAY (0x20/4)
#define RCIN_NAVIO_PCMCLK_CNTL 38
#define RCIN_NAVIO_PCMCLK_DIV 39
extern const AP_HAL::HAL& hal;
using namespace Linux;
volatile uint32_t *LinuxRCInput_Navio::pcm_reg;
volatile uint32_t *LinuxRCInput_Navio::clk_reg;
volatile uint32_t *LinuxRCInput_Navio::dma_reg;
Memory_table::Memory_table()
{
_page_count = 0;
}
//Init Memory table
Memory_table::Memory_table(uint32_t page_count, int version)
{
uint32_t i;
int fdMem, file;
//Cache coherent adresses depends on RPI's version
uint32_t bus = version == 1 ? 0x40000000 : 0xC0000000;
uint64_t pageInfo;
void* offset;
_virt_pages = (void**)malloc(page_count * sizeof(void*));
_phys_pages = (void**)malloc(page_count * sizeof(void*));
_page_count = page_count;
if ((fdMem = open("/dev/mem", O_RDWR | O_SYNC)) < 0) {
fprintf(stderr,"Failed to open /dev/mem\n");
exit(-1);
}
if ((file = open("/proc/self/pagemap", O_RDWR | O_SYNC)) < 0) {
fprintf(stderr,"Failed to open /proc/self/pagemap\n");
exit(-1);
}
//Magic to determine the physical address for this page:
offset = mmap(0, _page_count*PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS|MAP_NORESERVE|MAP_LOCKED,-1,0);
lseek(file, ((uint32_t)offset)/PAGE_SIZE*8, SEEK_SET);
//Get list of available cache coherent physical addresses
for (i = 0; i < _page_count; i++) {
_virt_pages[i] = mmap(0, PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS|MAP_NORESERVE|MAP_LOCKED,-1,0);
::read(file, &pageInfo, 8);
_phys_pages[i] = (void*)((uint32_t)(pageInfo*PAGE_SIZE) | bus);
}
//Map physical addresses to virtual memory
for (i = 0; i < _page_count; i++) {
munmap(_virt_pages[i], PAGE_SIZE);
_virt_pages[i] = mmap(_virt_pages[i], PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED|MAP_NORESERVE|MAP_LOCKED, fdMem, ((uint32_t)_phys_pages[i] & (version == 1 ? 0xFFFFFFFF : ~bus)));
memset(_virt_pages[i], 0xee, PAGE_SIZE);
}
close(file);
close(fdMem);
}
Memory_table::~Memory_table()
{
free(_virt_pages);
free(_phys_pages);
}
// This function returns physical address with help of pointer, which is offset from the beginning of the buffer.
void* Memory_table::get_page(void** const pages, uint32_t addr) const
{
if (addr >= PAGE_SIZE * _page_count) {
return NULL;
}
return (uint8_t*)pages[(uint32_t) addr / 4096] + addr % 4096;
}
//Get virtual address from the corresponding physical address from memory_table.
void* Memory_table::get_virt_addr(const uint32_t phys_addr) const
{
// FIXME: Can't the address be calculated directly?
// FIXME: if the address room in _phys_pages is not fragmented one may avoid a complete loop ..
uint32_t i = 0;
for (; i < _page_count; i++) {
if ((uint32_t) _phys_pages[i] == (((uint32_t) phys_addr) & 0xFFFFF000)) {
return (void*) ((uint32_t) _virt_pages[i] + (phys_addr & 0xFFF));
}
}
return NULL;
}
// FIXME: in-congruent function style see above
// This function returns offset from the beginning of the buffer using virtual address and memory_table.
uint32_t Memory_table::get_offset(void ** const pages, const uint32_t addr) const
{
uint32_t i = 0;
for (; i < _page_count; i++) {
if ((uint32_t) pages[i] == (addr & 0xFFFFF000) ) {
return (i*PAGE_SIZE + (addr & 0xFFF));
}
}
return -1;
}
//How many bytes are available for reading in circle buffer?
uint32_t Memory_table::bytes_available(const uint32_t read_addr, const uint32_t write_addr) const
{
if (write_addr > read_addr) {
return (write_addr - read_addr);
}
else {
return _page_count * PAGE_SIZE - (read_addr - write_addr);
}
}
uint32_t Memory_table::get_page_count() const
{
return _page_count;
}
// More memory mapping
int get_raspberry_pi_version()
{
char buffer[RCIN_NAVIO_MAX_SIZE_LINE];
const char* hardware_description_entry = "Hardware";
const char* v1 = "BCM2708";
const char* v2 = "BCM2709";
char* flag;
FILE* fd;
fd = fopen("/proc/cpuinfo", "r");
while (fgets(buffer, RCIN_NAVIO_MAX_SIZE_LINE, fd) != NULL) {
flag = strstr(buffer, hardware_description_entry);
if (flag != NULL) {
if (strstr(buffer, v2) != NULL) {
printf("Raspberry Pi 2 with BCM2709!\n");
fclose(fd);
return 2;
}
else if (strstr(buffer, v1) != NULL) {
printf("Raspberry Pi 1 with BCM2708!\n");
fclose(fd);
return 1;
}
}
}
return 0;
}
//Physical addresses of peripheral depends on Raspberry Pi's version
void LinuxRCInput_Navio::set_physical_addresses(int version)
{
if (version == 1) {
dma_base = RCIN_NAVIO_RPI1_DMA_BASE;
clk_base = RCIN_NAVIO_RPI1_CLK_BASE;
pcm_base = RCIN_NAVIO_RPI1_PCM_BASE;
}
else if (version == 2) {
dma_base = RCIN_NAVIO_RPI2_DMA_BASE;
clk_base = RCIN_NAVIO_RPI2_CLK_BASE;
pcm_base = RCIN_NAVIO_RPI2_PCM_BASE;
}
}
//Map peripheral to virtual memory
void* LinuxRCInput_Navio::map_peripheral(uint32_t base, uint32_t len)
{
int fd = open("/dev/mem", O_RDWR);
void * vaddr;
if (fd < 0) {
printf("Failed to open /dev/mem: %m\n");
return NULL;
}
vaddr = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_SHARED, fd, base);
if (vaddr == MAP_FAILED) {
printf("rpio-pwm: Failed to map peripheral at 0x%08x: %m\n", base);
}
close(fd);
return vaddr;
}
//Method to init DMA control block
void LinuxRCInput_Navio::init_dma_cb(dma_cb_t** cbp, uint32_t mode, uint32_t source, uint32_t dest, uint32_t length, uint32_t stride, uint32_t next_cb)
{
(*cbp)->info = mode;
(*cbp)->src = source;
(*cbp)->dst = dest;
(*cbp)->length = length;
(*cbp)->next = next_cb;
(*cbp)->stride = stride;
}
void LinuxRCInput_Navio::stop_dma()
{
dma_reg[RCIN_NAVIO_DMA_CS | RCIN_NAVIO_DMA_CHANNEL << 8] = 0;
}
/* We need to be sure that the DMA is stopped upon termination */
void LinuxRCInput_Navio::termination_handler(int signum)
{
stop_dma();
hal.scheduler->panic("Interrupted");
}
//This function is used to init DMA control blocks (setting sampling GPIO register, destination adresses, synchronization)
void LinuxRCInput_Navio::init_ctrl_data()
{
uint32_t phys_fifo_addr;
uint32_t dest = 0;
uint32_t cbp = 0;
dma_cb_t* cbp_curr;
//Set fifo addr (for delay)
phys_fifo_addr = ((pcm_base + 0x04) & 0x00FFFFFF) | 0x7e000000;
//Init dma control blocks.
/*We are transferring 1 byte of GPIO register. Every 56th iteration we are
sampling TIMER register, which length is 8 bytes. So, for every 56 samples of GPIO we need
56 * 1 + 8 = 64 bytes of buffer. Value 56 was selected specially to have a 64-byte "block"
TIMER - GPIO. So, we have integer count of such "blocks" at one virtual page. (4096 / 64 = 64
"blocks" per page. As minimum, we must have 2 virtual pages of buffer (to have integer count of
vitual pages for control blocks): for every 56 iterations (64 bytes of buffer) we need 56 control blocks for GPIO
sampling, 56 control blocks for setting frequency and 1 control block for sampling timer, so,
we need 56 + 56 + 1 = 113 control blocks. For integer value, we need 113 pages of control blocks.
Each control block length is 32 bytes. In 113 pages we will have (113 * 4096 / 32) = 113 * 128 control
blocks. 113 * 128 control blocks = 64 * 128 bytes of buffer = 2 pages of buffer.
So, for 56 * 64 * 2 iteration we init DMA for sampling GPIO
and timer to (64 * 64 * 2) = 8192 bytes = 2 pages of buffer.
*/
// fprintf(stderr, "ERROR SEARCH1\n");
uint32_t i = 0;
for (i = 0; i < 56 * 128 * RCIN_NAVIO_BUFFER_LENGTH; i++) // 8 * 56 * 128 == 57344
{
//Transfer timer every 56th sample
if(i % 56 == 0) {
cbp_curr = (dma_cb_t*)con_blocks->get_page(con_blocks->_virt_pages, cbp);
init_dma_cb(&cbp_curr, RCIN_NAVIO_DMA_NO_WIDE_BURSTS | RCIN_NAVIO_DMA_WAIT_RESP | RCIN_NAVIO_DMA_DEST_INC | RCIN_NAVIO_DMA_SRC_INC, RCIN_NAVIO_TIMER_BASE, (uint32_t) circle_buffer->get_page(circle_buffer->_phys_pages, dest), 8, 0, (uint32_t) con_blocks->get_page(con_blocks->_phys_pages, cbp + sizeof(dma_cb_t)));
dest += 8;
cbp += sizeof(dma_cb_t);
}
// Transfer GPIO (1 byte)
cbp_curr = (dma_cb_t*)con_blocks->get_page(con_blocks->_virt_pages, cbp);
init_dma_cb(&cbp_curr, RCIN_NAVIO_DMA_NO_WIDE_BURSTS | RCIN_NAVIO_DMA_WAIT_RESP, RCIN_NAVIO_GPIO_LEV0_ADDR, (uint32_t) circle_buffer->get_page(circle_buffer->_phys_pages, dest), 1, 0, (uint32_t) con_blocks->get_page(con_blocks->_phys_pages, cbp + sizeof(dma_cb_t)));
dest += 1;
cbp += sizeof(dma_cb_t);
// Delay (for setting sampling frequency)
/* DMA is waiting data request signal (DREQ) from PCM. PCM is set for 1 MhZ freqency, so,
each sample of GPIO is limited by writing to PCA queue.
*/
cbp_curr = (dma_cb_t*)con_blocks->get_page(con_blocks->_virt_pages, cbp);
init_dma_cb(&cbp_curr, RCIN_NAVIO_DMA_NO_WIDE_BURSTS | RCIN_NAVIO_DMA_WAIT_RESP | RCIN_NAVIO_DMA_D_DREQ | RCIN_NAVIO_DMA_PER_MAP(2), RCIN_NAVIO_TIMER_BASE, phys_fifo_addr, 4, 0, (uint32_t) con_blocks->get_page(con_blocks->_phys_pages, cbp + sizeof(dma_cb_t)));
cbp += sizeof(dma_cb_t);
}
//Make last control block point to the first (to make circle)
cbp -= sizeof(dma_cb_t);
((dma_cb_t*)con_blocks->get_page(con_blocks->_virt_pages, cbp))->next = (uint32_t) con_blocks->get_page(con_blocks->_phys_pages, 0);
}
/*Initialise PCM
See BCM2835 documentation:
http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf
*/
void LinuxRCInput_Navio::init_PCM()
{
pcm_reg[RCIN_NAVIO_PCM_CS_A] = 1; // Disable Rx+Tx, Enable PCM block
hal.scheduler->delay_microseconds(100);
clk_reg[RCIN_NAVIO_PCMCLK_CNTL] = 0x5A000006; // Source=PLLD (500MHz)
hal.scheduler->delay_microseconds(100);
clk_reg[RCIN_NAVIO_PCMCLK_DIV] = 0x5A000000 | ((50000/RCIN_NAVIO_SAMPLE_FREQ)<<12); // Set pcm div. If we need to configure DMA frequency.
hal.scheduler->delay_microseconds(100);
clk_reg[RCIN_NAVIO_PCMCLK_CNTL] = 0x5A000016; // Source=PLLD and enable
hal.scheduler->delay_microseconds(100);
pcm_reg[RCIN_NAVIO_PCM_TXC_A] = 0<<31 | 1<<30 | 0<<20 | 0<<16; // 1 channel, 8 bits
hal.scheduler->delay_microseconds(100);
pcm_reg[RCIN_NAVIO_PCM_MODE_A] = (10 - 1) << 10; //PCM mode
hal.scheduler->delay_microseconds(100);
pcm_reg[RCIN_NAVIO_PCM_CS_A] |= 1<<4 | 1<<3; // Clear FIFOs
hal.scheduler->delay_microseconds(100);
pcm_reg[RCIN_NAVIO_PCM_DREQ_A] = 64<<24 | 64<<8; // DMA Req when one slot is free?
hal.scheduler->delay_microseconds(100);
pcm_reg[RCIN_NAVIO_PCM_CS_A] |= 1<<9; // Enable DMA
hal.scheduler->delay_microseconds(100);
pcm_reg[RCIN_NAVIO_PCM_CS_A] |= 1<<2; // Enable Tx
hal.scheduler->delay_microseconds(100);
}
/*Initialise DMA
See BCM2835 documentation:
http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf
*/
void LinuxRCInput_Navio::init_DMA()
{
dma_reg[RCIN_NAVIO_DMA_CS | RCIN_NAVIO_DMA_CHANNEL << 8] = RCIN_NAVIO_DMA_RESET; //Reset DMA
hal.scheduler->delay_microseconds(100);
dma_reg[RCIN_NAVIO_DMA_CS | RCIN_NAVIO_DMA_CHANNEL << 8] = RCIN_NAVIO_DMA_INT | RCIN_NAVIO_DMA_END;
dma_reg[RCIN_NAVIO_DMA_CONBLK_AD | RCIN_NAVIO_DMA_CHANNEL << 8] = reinterpret_cast<uint32_t>(con_blocks->get_page(con_blocks->_phys_pages, 0));//Set first control block address
dma_reg[RCIN_NAVIO_DMA_DEBUG | RCIN_NAVIO_DMA_CHANNEL << 8] = 7; // clear debug error flags
dma_reg[RCIN_NAVIO_DMA_CS | RCIN_NAVIO_DMA_CHANNEL << 8] = 0x10880001; // go, mid priority, wait for outstanding writes
}
//We must stop DMA when the process is killed
void LinuxRCInput_Navio::set_sigaction()
{
for (int i = 0; i < 64; i++) {
//catch all signals (like ctrl+c, ctrl+z, ...) to ensure DMA is disabled
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = LinuxRCInput_Navio::termination_handler;
sigaction(i, &sa, NULL);
}
}
//Initial setup of variables
LinuxRCInput_Navio::LinuxRCInput_Navio():
prev_tick(0),
delta_time(0),
curr_tick_inc(1000/RCIN_NAVIO_SAMPLE_FREQ),
curr_pointer(0),
curr_channel(0),
width_s0(0),
curr_signal(0),
last_signal(228),
state(RCIN_NAVIO_INITIAL_STATE)
{
int version = get_raspberry_pi_version();
set_physical_addresses(version);
//Init memory for buffer and for DMA control blocks. See comments in "init_ctrl_data()" to understand values "2" and "113"
circle_buffer = new Memory_table(RCIN_NAVIO_BUFFER_LENGTH * 2, version);
con_blocks = new Memory_table(RCIN_NAVIO_BUFFER_LENGTH * 113, version);
}
LinuxRCInput_Navio::~LinuxRCInput_Navio()
{
delete circle_buffer;
delete con_blocks;
}
void LinuxRCInput_Navio::deinit()
{
stop_dma();
}
//Initializing necessary registers
void LinuxRCInput_Navio::init_registers()
{
dma_reg = (uint32_t*)map_peripheral(dma_base, RCIN_NAVIO_DMA_LEN);
pcm_reg = (uint32_t*)map_peripheral(pcm_base, RCIN_NAVIO_PCM_LEN);
clk_reg = (uint32_t*)map_peripheral(clk_base, RCIN_NAVIO_CLK_LEN);
}
void LinuxRCInput_Navio::init(void*)
{
init_registers();
//Enable PPM input
enable_pin = hal.gpio->channel(PPM_INPUT_NAVIO);
enable_pin->mode(HAL_GPIO_INPUT);
//Configuration
set_sigaction();
init_ctrl_data();
init_PCM();
init_DMA();
//wait a bit to let DMA fill queues and come to stable sampling
hal.scheduler->delay(300);
//Reading first sample
curr_tick = *((uint64_t*) circle_buffer->get_page(circle_buffer->_virt_pages, curr_pointer));
prev_tick = curr_tick;
curr_pointer += 8;
curr_signal = *((uint8_t*) circle_buffer->get_page(circle_buffer->_virt_pages, curr_pointer)) & 0x10 ? 1 : 0;
last_signal = curr_signal;
curr_pointer++;
}
//Processing signal
void LinuxRCInput_Navio::_timer_tick()
{
int j;
void* x;
//Now we are getting address in which DMAC is writing at current moment
dma_cb_t* ad = (dma_cb_t*) con_blocks->get_virt_addr(dma_reg[RCIN_NAVIO_DMA_CONBLK_AD | RCIN_NAVIO_DMA_CHANNEL << 8]);
for(j = 1; j >= -1; j--){
x = circle_buffer->get_virt_addr((ad + j)->dst);
if(x != NULL) {
break;}
}
//How many bytes have DMA transfered (and we can process)?
counter = circle_buffer->bytes_available(curr_pointer, circle_buffer->get_offset(circle_buffer->_virt_pages, (uint32_t)x));
//We can't stay in method for a long time, because it may lead to delays
if (counter > RCIN_NAVIO_MAX_COUNTER) {
counter = RCIN_NAVIO_MAX_COUNTER;
}
//Processing ready bytes
for (;counter > 0x40;counter--) {
//Is it timer samle?
if (curr_pointer % (64) == 0) {
curr_tick = *((uint64_t*) circle_buffer->get_page(circle_buffer->_virt_pages, curr_pointer));
curr_pointer+=8;
counter-=8;
}
//Reading required bit
curr_signal = *((uint8_t*) circle_buffer->get_page(circle_buffer->_virt_pages, curr_pointer)) & 0x10 ? 1 : 0;
//If the signal changed
if (curr_signal != last_signal) {
delta_time = curr_tick - prev_tick;
prev_tick = curr_tick;
switch (state) {
case RCIN_NAVIO_INITIAL_STATE:
state = RCIN_NAVIO_ZERO_STATE;
break;
case RCIN_NAVIO_ZERO_STATE:
if (curr_signal == 0) {
width_s0 = (uint16_t) delta_time;
state = RCIN_NAVIO_ONE_STATE;
break;
}
else
break;
case RCIN_NAVIO_ONE_STATE:
if (curr_signal == 1) {
width_s1 = (uint16_t) delta_time;
state = RCIN_NAVIO_ZERO_STATE;
_process_rc_pulse(width_s0, width_s1);
break;
}
else
break;
}
}
last_signal = curr_signal;
curr_pointer++;
if (curr_pointer >= circle_buffer->get_page_count()*PAGE_SIZE) {
curr_pointer = 0;
}
curr_tick+=curr_tick_inc;
}
}
#endif // CONFIG_HAL_BOARD_SUBTYPE