Add pcm module. (#1255)

* Add pcm module.
* Add network streaming example.
* document hw_timer dependency with pwm
* Add vu peak callback.

app/Makefile

@@ -24,6 +24,7 @@ SPECIAL_MKTARGETS=$(APP_MKTARGETS)
 SUBDIRS= 					\
 	user 					\
 	driver 					\
+	pcm					\
 	platform 				\
 	libc 					\
 	lua 					\
@@ -69,6 +70,7 @@ LD_FILE = $(LDDIR)/nodemcu.ld
 COMPONENTS_eagle.app.v6 = 			\
 	user/libuser.a 				\
 	driver/libdriver.a 			\
+	pcm/pcm.a				\
 	platform/libplatform.a 			\
 	task/libtask.a 				\
 	libc/liblibc.a 				\

app/driver/sigma_delta.c

@@ -1,4 +1,5 @@
 
+#include "platform.h"
 #include "driver/sigma_delta.h"
 
 
@@ -18,7 +19,7 @@ void sigma_delta_stop( void )
                    GPIO_SIGMA_DELTA_PRESCALE_SET(0x00) );
 }
 
-void sigma_delta_set_prescale_target( sint16 prescale, sint16 target )
+void ICACHE_RAM_ATTR sigma_delta_set_prescale_target( sint16 prescale, sint16 target )
 {
     uint32_t prescale_mask, target_mask;
 

app/include/task/task.h

@@ -4,6 +4,7 @@
 #include "ets_sys.h"
 #include "osapi.h"
 #include "os_type.h"
+#include "user_interface.h"
 
 /* use LOW / MEDIUM / HIGH since it isn't clear from the docs which is higher */
 

app/include/user_modules.h

@@ -42,6 +42,7 @@
 #define LUA_USE_MODULES_NET
 #define LUA_USE_MODULES_NODE
 #define LUA_USE_MODULES_OW
+//#define LUA_USE_MODULES_PCM
 //#define LUA_USE_MODULES_PERF
 //#define LUA_USE_MODULES_PWM
 //#define LUA_USE_MODULES_RC

app/modules/Makefile

@@ -46,6 +46,7 @@ INCLUDES += -I ../mqtt
 INCLUDES += -I ../u8glib
 INCLUDES += -I ../ucglib
 INCLUDES += -I ../lua
+INCLUDES += -I ../pcm
 INCLUDES += -I ../platform
 INCLUDES += -I ../spiffs
 INCLUDES += -I ../smart

app/modules/pcm.c

@@ -0,0 +1,263 @@
+// Module for interfacing with PCM functionality
+
+#include "module.h"
+#include "lauxlib.h"
+#include "task/task.h"
+#include "c_string.h"
+#include "c_stdlib.h"
+
+#include "pcm.h"
+#include "pcm_drv.h"
+
+
+#define GET_PUD() pud_t *pud = (pud_t *)luaL_checkudata(L, 1, "pcm.driver"); \
+  cfg_t *cfg = &(pud->cfg);
+
+#define UNREF_CB(_cb) luaL_unref( L, LUA_REGISTRYINDEX, _cb ); \
+  _cb = LUA_NOREF;
+
+#define COND_REF(_cond) _cond ? luaL_ref( L, LUA_REGISTRYINDEX ) : LUA_NOREF
+
+
+static void dispatch_callback( lua_State *L, int self_ref, int cb_ref, int returns )
+{
+  if (cb_ref != LUA_NOREF) {
+    lua_rawgeti( L, LUA_REGISTRYINDEX, cb_ref );
+    lua_rawgeti( L, LUA_REGISTRYINDEX, self_ref );
+    lua_call( L, 1, returns );
+  }
+}
+
+static int pcm_drv_free( lua_State *L )
+{
+  GET_PUD();
+
+  UNREF_CB( cfg->cb_data_ref );
+  UNREF_CB( cfg->cb_drained_ref );
+  UNREF_CB( cfg->cb_paused_ref );
+  UNREF_CB( cfg->cb_stopped_ref );
+  UNREF_CB( cfg->cb_vu_ref );
+  UNREF_CB( cfg->self_ref );
+
+  if (cfg->bufs[0].data) {
+    c_free( cfg->bufs[0].data );
+    cfg->bufs[0].data = NULL;
+  }
+  if (cfg->bufs[1].data) {
+    c_free( cfg->bufs[1].data );
+    cfg->bufs[1].data = NULL;
+  }
+
+  return 0;
+}
+
+// Lua: drv:close()
+static int pcm_drv_close( lua_State *L )
+{
+  GET_PUD();
+
+  pud->drv->close( cfg );
+
+  return pcm_drv_free( L );
+}
+
+// Lua: drv:stop(self)
+static int pcm_drv_stop( lua_State *L )
+{
+  GET_PUD();
+
+  // throttle ISR and reader
+  cfg->isr_throttled = -1;
+
+  pud->drv->stop( cfg );
+
+  // invalidate the buffers
+  cfg->bufs[0].empty = cfg->bufs[1].empty = TRUE;
+
+  dispatch_callback( L, cfg->self_ref, cfg->cb_stopped_ref, 0 );
+
+  return 0;
+}
+
+// Lua: drv:pause(self)
+static int pcm_drv_pause( lua_State *L )
+{
+  GET_PUD();
+
+  // throttle ISR and reader
+  cfg->isr_throttled = -1;
+
+  pud->drv->stop( cfg );
+
+  dispatch_callback( L, cfg->self_ref, cfg->cb_paused_ref, 0 );
+
+  return 0;
+}
+
+static void pcm_start_play_task( task_param_t param, uint8 prio )
+{
+  lua_State *L = lua_getstate();
+  pud_t *pud = (pud_t *)param;
+  cfg_t *cfg = &(pud->cfg);
+
+  // stop driver before starting it in case it hasn't been stopped from Lua
+  pud->drv->stop( cfg );
+
+  if (!pud->drv->play( cfg )) {
+      luaL_error( L, "pcm driver start" );
+  }
+
+  // unthrottle ISR and reader
+  pud->cfg.isr_throttled = 0;
+}
+
+// Lua: drv:play(self, rate)
+static int pcm_drv_play( lua_State *L )
+{
+  GET_PUD();
+
+  cfg->rate = luaL_optinteger( L, 2, PCM_RATE_8K );
+
+  luaL_argcheck( L, (cfg->rate >= PCM_RATE_1K) && (cfg->rate <= PCM_RATE_16K), 2, "invalid bit rate" );
+
+  if (cfg->self_ref == LUA_NOREF) {
+    lua_pushvalue( L, 1 );  // copy self userdata to the top of stack
+    cfg->self_ref = luaL_ref( L, LUA_REGISTRYINDEX );
+  }
+
+  // schedule actions for play in separate task since drv:play() might have been called
+  // in the callback fn of pcm_data_play_task() which in turn gets called when starting play...
+  task_post_low( cfg->start_play_task, (os_param_t)pud );
+
+  return 0;
+}
+
+// Lua: drv.on(self, event, cb_fn)
+static int pcm_drv_on( lua_State *L )
+{
+  size_t len;
+  const char *event;
+  uint8_t is_func = FALSE;
+
+  GET_PUD();
+
+  event = luaL_checklstring( L, 2, &len );
+
+  if ((lua_type( L, 3 ) == LUA_TFUNCTION) ||
+      (lua_type( L, 3 ) == LUA_TLIGHTFUNCTION)) {
+    lua_pushvalue( L, 3 );  // copy argument (func) to the top of stack
+    is_func = TRUE;
+  }
+
+  if ((len == 4) && (c_strcmp( event, "data" ) == 0)) {
+    luaL_unref( L, LUA_REGISTRYINDEX, cfg->cb_data_ref);
+    cfg->cb_data_ref = COND_REF( is_func );
+  } else if ((len == 7) && (c_strcmp( event, "drained" ) == 0)) {
+    luaL_unref( L, LUA_REGISTRYINDEX, cfg->cb_drained_ref);
+    cfg->cb_drained_ref = COND_REF( is_func );
+  } else if ((len == 6) && (c_strcmp( event, "paused" ) == 0)) {
+    luaL_unref( L, LUA_REGISTRYINDEX, cfg->cb_paused_ref);
+    cfg->cb_paused_ref = COND_REF( is_func );
+  } else if ((len == 7) && (c_strcmp( event, "stopped" ) == 0)) {
+    luaL_unref( L, LUA_REGISTRYINDEX, cfg->cb_stopped_ref);
+    cfg->cb_stopped_ref = COND_REF( is_func );
+  } else if ((len == 2) && (c_strcmp( event, "vu" ) == 0)) {
+    luaL_unref( L, LUA_REGISTRYINDEX, cfg->cb_vu_ref);
+    cfg->cb_vu_ref = COND_REF( is_func );
+
+    int freq = luaL_optinteger( L, 4, 10 );
+    luaL_argcheck( L, (freq > 0) && (freq <= 200), 4, "invalid range" );
+    cfg->vu_freq = (uint8_t)freq;
+  } else {
+    if (is_func) {
+      // need to pop pushed function arg
+      lua_pop( L, 1 );
+    }
+    return luaL_error( L, "method not supported" );
+  }
+
+  return 0;
+}
+
+// Lua: pcm.new( type, pin )
+static int pcm_new( lua_State *L )
+{
+  pud_t *pud = (pud_t *) lua_newuserdata( L, sizeof( pud_t ) );
+  cfg_t *cfg = &(pud->cfg);
+  int driver;
+
+  cfg->rbuf_idx = cfg->fbuf_idx = 0;
+  cfg->isr_throttled = -1;  // start ISR and reader in throttled mode
+
+  driver = luaL_checkinteger( L, 1 );
+  luaL_argcheck( L, (driver >= 0) && (driver < PCM_DRIVER_END), 1, "invalid driver" );
+
+  cfg->self_ref      = LUA_NOREF;
+  cfg->cb_data_ref   = cfg->cb_drained_ref = LUA_NOREF;
+  cfg->cb_paused_ref = cfg->cb_stopped_ref = LUA_NOREF;
+  cfg->cb_vu_ref     = LUA_NOREF;
+
+  cfg->bufs[0].buf_size = cfg->bufs[1].buf_size = 0;
+  cfg->bufs[0].data     = cfg->bufs[1].data     = NULL;
+  cfg->bufs[0].len      = cfg->bufs[1].len      = 0;
+  cfg->bufs[0].rpos     = cfg->bufs[1].rpos     = 0;
+  cfg->bufs[0].empty    = cfg->bufs[1].empty    = TRUE;
+
+  cfg->data_vu_task    = task_get_id( pcm_data_vu_task );
+  cfg->vu_freq         = 10;
+  cfg->data_play_task  = task_get_id( pcm_data_play_task );
+  cfg->start_play_task = task_get_id( pcm_start_play_task );
+
+  if (driver == PCM_DRIVER_SD) {
+    cfg->pin = luaL_checkinteger( L, 2 );
+    MOD_CHECK_ID(sigma_delta, cfg->pin);
+
+    pud->drv = &pcm_drv_sd;
+
+    pud->drv->init( cfg );
+
+    /* set its metatable */
+    lua_pushvalue( L, -1 );  // copy self userdata to the top of stack
+    luaL_getmetatable( L, "pcm.driver" );
+    lua_setmetatable( L, -2 );
+
+    return 1;
+  } else {
+    pud->drv = NULL;
+    return 0;
+  }
+}
+
+
+static const LUA_REG_TYPE pcm_driver_map[] = {
+  { LSTRKEY( "play" ),    LFUNCVAL( pcm_drv_play ) },
+  { LSTRKEY( "pause" ),   LFUNCVAL( pcm_drv_pause ) },
+  { LSTRKEY( "stop" ),    LFUNCVAL( pcm_drv_stop ) },
+  { LSTRKEY( "close" ),   LFUNCVAL( pcm_drv_close ) },
+  { LSTRKEY( "on" ),      LFUNCVAL( pcm_drv_on ) },
+  { LSTRKEY( "__gc" ),    LFUNCVAL( pcm_drv_free ) },
+  { LSTRKEY( "__index" ), LROVAL( pcm_driver_map ) },
+  { LNILKEY, LNILVAL }
+};
+
+// Module function map
+static const LUA_REG_TYPE pcm_map[] = {
+  { LSTRKEY( "new" ),      LFUNCVAL( pcm_new ) },
+  { LSTRKEY( "SD" ),       LNUMVAL( PCM_DRIVER_SD ) },
+  { LSTRKEY( "RATE_1K" ),  LNUMVAL( PCM_RATE_1K ) },
+  { LSTRKEY( "RATE_2K" ),  LNUMVAL( PCM_RATE_2K ) },
+  { LSTRKEY( "RATE_4K" ),  LNUMVAL( PCM_RATE_4K ) },
+  { LSTRKEY( "RATE_5K" ),  LNUMVAL( PCM_RATE_5K ) },
+  { LSTRKEY( "RATE_8K" ),  LNUMVAL( PCM_RATE_8K ) },
+  { LSTRKEY( "RATE_10K" ), LNUMVAL( PCM_RATE_10K ) },
+  { LSTRKEY( "RATE_12K" ), LNUMVAL( PCM_RATE_12K ) },
+  { LSTRKEY( "RATE_16K" ), LNUMVAL( PCM_RATE_16K ) },
+  { LNILKEY, LNILVAL }
+};
+
+int luaopen_pcm( lua_State *L ) {
+  luaL_rometatable( L, "pcm.driver", (void *)pcm_driver_map );  // create metatable
+  return 0;
+}
+
+NODEMCU_MODULE(PCM, "pcm", pcm_map, luaopen_pcm);

app/pcm/Makefile

@@ -0,0 +1,47 @@
+
+#############################################################
+# Required variables for each makefile
+# Discard this section from all parent makefiles
+# Expected variables (with automatic defaults):
+#   CSRCS (all "C" files in the dir)
+#   SUBDIRS (all subdirs with a Makefile)
+#   GEN_LIBS - list of libs to be generated ()
+#   GEN_IMAGES - list of images to be generated ()
+#   COMPONENTS_xxx - a list of libs/objs in the form
+#     subdir/lib to be extracted and rolled up into
+#     a generated lib/image xxx.a ()
+#
+ifndef PDIR
+GEN_LIBS = pcm.a
+endif
+
+STD_CFLAGS=-std=gnu11 -Wimplicit
+
+#############################################################
+# Configuration i.e. compile options etc.
+# Target specific stuff (defines etc.) goes in here!
+# Generally values applying to a tree are captured in the
+#   makefile at its root level - these are then overridden
+#   for a subtree within the makefile rooted therein
+#
+#DEFINES += 
+
+#############################################################
+# Recursion Magic - Don't touch this!!
+#
+# Each subtree potentially has an include directory
+#   corresponding to the common APIs applicable to modules
+#   rooted at that subtree. Accordingly, the INCLUDE PATH
+#   of a module can only contain the include directories up
+#   its parent path, and not its siblings
+#
+# Required for each makefile to inherit from the parent
+#
+
+INCLUDES := $(INCLUDES) -I $(PDIR)include
+INCLUDES += -I ./
+INCLUDES += -I ../lua
+INCLUDES += -I ../libc
+INCLUDES += -I ../platform
+PDIR := ../$(PDIR)
+sinclude $(PDIR)Makefile