nodemcu-firmware/components/modules/i2c.c

241 lines
6.9 KiB
C

// Module for interfacing with the ESP32 I2C interfaces
#include "module.h"
#include "lauxlib.h"
#include "lextra.h"
#include "platform.h"
#include "i2c_common.h"
// Lua: speed = i2c.setup( id, sda, scl, speed [,stretchfactor] )
static int i2c_setup( lua_State *L )
{
unsigned id = luaL_checkinteger( L, 1 );
unsigned sda = luaL_checkinteger( L, 2 );
unsigned scl = luaL_checkinteger( L, 3 );
uint32_t speed = (uint32_t)luaL_checkinteger( L, 4 );
int stretchfactor = 1;
int timeout;
luaL_argcheck( L, id < I2C_ID_MAX, 1, "invalid i2c interface id" );
MOD_CHECK_ID( gpio, sda );
MOD_CHECK_ID( gpio, scl );
if (id == I2C_ID_SW) {
luaL_argcheck( L, speed <= PLATFORM_I2C_SPEED_SLOW, 4, "i2c speed too high for i2c.SW interface" );
if (!platform_i2c_setup( id, sda, scl, (uint32_t)speed ))
luaL_error( L, "setup failed" );
lua_pushinteger(L,speed);
} else {
luaL_argcheck( L, speed <= PLATFORM_I2C_SPEED_FASTPLUS, 4, "i2c speed too high for i2c.HWx interfaces" );
if (lua_gettop( L ) > 4) stretchfactor = luaL_checkinteger( L, 5 );
timeout=li2c_hw_master_setup( L, id, sda, scl, speed, stretchfactor);
lua_pushinteger(L,timeout);
}
return 1;
}
// Lua: i2c.start( id )
static int i2c_start( lua_State *L )
{
unsigned id = luaL_checkinteger( L, 1 );
luaL_argcheck( L, id < I2C_ID_MAX, 1, "invalid i2c interface id" );
if (id == I2C_ID_SW) {
if (!platform_i2c_send_start( id ))
luaL_error( L, "start command failed on i2c.SW interface");
} else {
li2c_hw_master_start( L, id );
}
return 0;
}
// Lua: i2c.stop( id )
static int i2c_stop( lua_State *L )
{
unsigned id = luaL_checkinteger( L, 1 );
luaL_argcheck( L, id < I2C_ID_MAX, 1, "invalid i2c interface id" );
if (id == I2C_ID_SW) {
if (!platform_i2c_send_stop( id ))
luaL_error( L, "stop command failed on i2c.SW interface" );
} else {
li2c_hw_master_stop( L, id );
}
return 0;
}
// Lua: status = i2c.address( id , address , direction [, ack_check_en] )
static int i2c_address( lua_State *L )
{
int stack = 0;
unsigned id = luaL_checkinteger( L, ++stack );
luaL_argcheck( L, id < I2C_ID_MAX, stack, "invalid i2c interface id" );
int address = luaL_checkinteger( L, ++stack );
luaL_argcheck( L, address >= 0 && address <= 127, stack, "i2c address out of 7-bit range" );
// *** FIX ME what about 10-bit addresses ???
int direction = luaL_checkinteger( L, ++stack );
luaL_argcheck( L,
direction == PLATFORM_I2C_DIRECTION_TRANSMITTER ||
direction == PLATFORM_I2C_DIRECTION_RECEIVER,
stack, "invalid i2c address direction" );
bool ack_check_en = luaL_optbool( L, ++stack, true );
int ret;
if (id == I2C_ID_SW) {
ret = platform_i2c_send_address( id, (uint16_t)address, direction, ack_check_en ? 1 : 0 );
} else {
ret = li2c_hw_master_address( L, id, (uint16_t)address, direction, ack_check_en );
// bad parameters could cause failure to enqueue, but all have been checked, so it should always return true
}
lua_pushboolean( L, ret > 0 );
return 1;
}
// Lua: wrote = i2c.write( id, data1, [data2], ..., [datan] [, ack_check_en] )
// each of the data elements can be either a string, a table or an 8-bit number
static int i2c_write( lua_State *L )
{
unsigned id = luaL_checkinteger( L, 1 );
luaL_argcheck( L, id < I2C_ID_MAX, 1, "invalid i2c interface id" );
const char *pdata;
size_t datalen, i;
int numdata;
uint32_t wrote = 0;
unsigned argn;
bool ack_check_en = true;
if (lua_isboolean( L, -1 )) {
ack_check_en = lua_toboolean( L, -1 );
lua_pop( L, 1 );
}
if( lua_gettop( L ) < 2 )
return luaL_error( L, "not enough or wrong arg types for i2c.write" );
for( argn = 2; argn <= lua_gettop( L ); argn ++ )
{
// lua_isnumber() would silently convert a string of digits to an integer
// whereas here strings are handled separately.
if( lua_type( L, argn ) == LUA_TNUMBER )
{
numdata = ( int )luaL_checkinteger( L, argn );
if( numdata < 0 || numdata > 255 )
return luaL_error( L, "numeric value for i2c.write does not fit in 1 byte" );
if (id == I2C_ID_SW) {
if( platform_i2c_send_byte( id, numdata, 1) != 1 && ack_check_en )
break;
} else {
li2c_hw_master_write( L, id, numdata, ack_check_en );
}
wrote ++;
}
else if( lua_istable( L, argn ) )
{
datalen = lua_objlen( L, argn );
for( i = 0; i < datalen; i ++ )
{
lua_rawgeti( L, argn, i + 1 );
numdata = ( int )luaL_checkinteger( L, -1 );
lua_pop( L, 1 );
if( numdata < 0 || numdata > 255 )
return luaL_error( L, "table value for i2c.write does not fit in 1 byte" );
if (id == I2C_ID_SW) {
if( platform_i2c_send_byte( id, numdata, 1 ) == 0 && ack_check_en)
break;
} else {
li2c_hw_master_write( L, id, numdata, ack_check_en );
}
}
wrote += i;
if( i < datalen )
break;
}
else
{
pdata = luaL_checklstring( L, argn, &datalen );
for( i = 0; i < datalen; i ++ )
if (id == I2C_ID_SW) {
if( platform_i2c_send_byte( id, pdata[ i ], 1 ) == 0 && ack_check_en)
break;
} else {
li2c_hw_master_write( L, id, pdata[ i ], ack_check_en );
}
wrote += i;
if( i < datalen )
break;
}
}
lua_pushinteger( L, wrote );
return 1;
}
// Lua: read = i2c.read( id, size ) for SW interface or i2c.read( id, size ) for HWx interfaces
static int i2c_read( lua_State *L )
{
unsigned id = luaL_checkinteger( L, 1 );
luaL_argcheck( L, id < I2C_ID_MAX, 1, "invalid i2c interface id" );
uint32_t size = ( uint32_t ) luaL_checkinteger( L, 2 );
luaL_argcheck( L, size > 0, 2, "i2c read size of 0 is invalid" );
if (id == I2C_ID_SW) {
luaL_Buffer b;
uint32_t i;
int data;
luaL_buffinit( L, &b );
for( i = 0; i < size; i ++ )
if( ( data = platform_i2c_recv_byte( id, i < size - 1 ) ) == -1 )
break;
else
luaL_addchar( &b, ( char )data );
luaL_pushresult( &b );
return 1;
} else {
li2c_hw_master_read( L, id, size );
return 0;
}
}
LROT_BEGIN(i2c)
LROT_FUNCENTRY( setup, i2c_setup )
LROT_FUNCENTRY( start, i2c_start )
LROT_FUNCENTRY( stop, i2c_stop )
LROT_FUNCENTRY( address, i2c_address )
LROT_FUNCENTRY( write, i2c_write )
LROT_FUNCENTRY( read, i2c_read )
LROT_FUNCENTRY( transfer, li2c_hw_master_transfer )
LROT_TABENTRY ( slave, li2c_slave )
LROT_NUMENTRY ( FASTPLUS, PLATFORM_I2C_SPEED_FASTPLUS )
LROT_NUMENTRY ( FAST, PLATFORM_I2C_SPEED_FAST )
LROT_NUMENTRY ( SLOW, PLATFORM_I2C_SPEED_SLOW )
LROT_NUMENTRY ( TRANSMITTER, PLATFORM_I2C_DIRECTION_TRANSMITTER )
LROT_NUMENTRY ( RECEIVER, PLATFORM_I2C_DIRECTION_RECEIVER )
LROT_NUMENTRY ( SW, I2C_ID_SW )
LROT_NUMENTRY ( HW0, I2C_ID_HW0 )
LROT_NUMENTRY ( HW1, I2C_ID_HW1 )
LROT_END(i2c, NULL, 0)
int luaopen_i2c( lua_State *L ) {
li2c_hw_master_init( L );
li2c_hw_slave_init( L );
return 0;
}
NODEMCU_MODULE(I2C, "i2c", i2c, luaopen_i2c);