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sbus: refactor the code using unified PIOS RCVR driver structure

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- allow more than one S.Bus receiver (needs hardware support)
- use dynamic memory allocation (frees around 72 bytes of RAM when unused)
This commit is contained in:
Oleg Semyonov 2011-10-20 18:23:23 +03:00
parent cb8d9c791c
commit 92b81e3f88
4 changed files with 209 additions and 92 deletions
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6
flight/PiOS/Boards/STM32103CB_CC_Rev1.h
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@ -227,6 +227,12 @@ extern uint32_t pios_com_telem_usb_id;
#define PIOS_SPEKTRUM_MAX_DEVS 2
#define PIOS_SPEKTRUM_NUM_INPUTS 12
//-------------------------
// Receiver S.Bus input
//-------------------------
#define PIOS_SBUS_MAX_DEVS 1
#define PIOS_SBUS_NUM_INPUTS (16+2)
//-------------------------
// Servo outputs
//-------------------------

6
flight/PiOS/Boards/STM3210E_OP.h
View File

@ -200,6 +200,12 @@ extern uint32_t pios_com_aux_id;
#define PIOS_SPEKTRUM_MAX_DEVS 1
#define PIOS_SPEKTRUM_NUM_INPUTS 12
//-------------------------
// Receiver S.Bus input
//-------------------------
#define PIOS_SBUS_MAX_DEVS 1
#define PIOS_SBUS_NUM_INPUTS (16+2)
//-------------------------
// Servo outputs
//-------------------------

280
flight/PiOS/STM32F10x/pios_sbus.c
View File

@ -3,12 +3,12 @@
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_SBUS Futaba S.Bus receiver functions
* @brief Code to read Futaba S.Bus input
* @brief Code to read Futaba S.Bus input serial stream
* @{
*
* @file pios_sbus.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2011.
* @brief USART commands. Inits USARTs, controls USARTs & Interrupt handlers. (STM32 dependent)
* @brief Code to read Futaba S.Bus input serial stream
* @see The GNU Public License (GPL) Version 3
*
*****************************************************************************/
@ -34,44 +34,166 @@
#if defined(PIOS_INCLUDE_SBUS)
/* Provide a RCVR driver */
/* Forward Declarations */
static int32_t PIOS_SBUS_Get(uint32_t rcvr_id, uint8_t channel);
static uint16_t PIOS_SBUS_RxInCallback(uint32_t context,
uint8_t *buf,
uint16_t buf_len,
uint16_t *headroom,
bool *need_yield);
static void PIOS_SBUS_Supervisor(uint32_t sbus_id);
/* Local Variables */
const struct pios_rcvr_driver pios_sbus_rcvr_driver = {
.read = PIOS_SBUS_Get,
};
/* Local Variables */
static uint16_t channel_data[SBUS_NUMBER_OF_CHANNELS];
static uint8_t received_data[SBUS_FRAME_LENGTH - 2];
static uint8_t receive_timer;
static uint8_t failsafe_timer;
static uint8_t frame_found;
enum pios_sbus_dev_magic {
PIOS_SBUS_DEV_MAGIC = 0x53427573,
};
static void PIOS_SBUS_Supervisor(uint32_t sbus_id);
struct pios_sbus_state {
uint16_t channel_data[PIOS_SBUS_NUM_INPUTS];
uint8_t received_data[SBUS_FRAME_LENGTH - 2];
uint8_t receive_timer;
uint8_t failsafe_timer;
uint8_t frame_found;
uint8_t byte_count;
};
/**
* reset_channels() function clears all channel data in case of
* lost signal or explicit failsafe flag from the S.Bus data stream
*/
static void reset_channels(void)
struct pios_sbus_dev {
enum pios_sbus_dev_magic magic;
const struct pios_sbus_cfg *cfg;
struct pios_sbus_state state;
};
/* Allocate S.Bus device descriptor */
#if defined(PIOS_INCLUDE_FREERTOS)
static struct pios_sbus_dev *PIOS_SBUS_Alloc(void)
{
for (int i = 0; i < SBUS_NUMBER_OF_CHANNELS; i++) {
channel_data[i] = PIOS_RCVR_TIMEOUT;
struct pios_sbus_dev *sbus_dev;
sbus_dev = (struct pios_sbus_dev *)pvPortMalloc(sizeof(*sbus_dev));
if (!sbus_dev) return(NULL);
sbus_dev->magic = PIOS_SBUS_DEV_MAGIC;
return(sbus_dev);
}
#else
static struct pios_sbus_dev pios_sbus_devs[PIOS_SBUS_MAX_DEVS];
static uint8_t pios_sbus_num_devs;
static struct pios_sbus_dev *PIOS_SBUS_Alloc(void)
{
struct pios_sbus_dev *sbus_dev;
if (pios_sbus_num_devs >= PIOS_SBUS_MAX_DEVS) {
return (NULL);
}
sbus_dev = &pios_sbus_devs[pios_sbus_num_devs++];
sbus_dev->magic = PIOS_SBUS_DEV_MAGIC;
return (sbus_dev);
}
#endif
/* Validate S.Bus device descriptor */
static bool PIOS_SBUS_Validate(struct pios_sbus_dev *sbus_dev)
{
return (sbus_dev->magic == PIOS_SBUS_DEV_MAGIC);
}
/* Reset channels in case of lost signal or explicit failsafe receiver flag */
static void PIOS_SBUS_ResetChannels(struct pios_sbus_state *state)
{
for (int i = 0; i < PIOS_SBUS_NUM_INPUTS; i++) {
state->channel_data[i] = PIOS_RCVR_TIMEOUT;
}
}
/* Reset S.Bus receiver state */
static void PIOS_SBUS_ResetState(struct pios_sbus_state *state)
{
state->receive_timer = 0;
state->failsafe_timer = 0;
state->frame_found = 0;
PIOS_SBUS_ResetChannels(state);
}
/* Initialise S.Bus receiver interface */
int32_t PIOS_SBUS_Init(uint32_t *sbus_id,
const struct pios_sbus_cfg *cfg,
const struct pios_com_driver *driver,
uint32_t lower_id)
{
PIOS_DEBUG_Assert(sbus_id);
PIOS_DEBUG_Assert(cfg);
PIOS_DEBUG_Assert(driver);
struct pios_sbus_dev *sbus_dev;
sbus_dev = (struct pios_sbus_dev *)PIOS_SBUS_Alloc();
if (!sbus_dev) goto out_fail;
/* Bind the configuration to the device instance */
sbus_dev->cfg = cfg;
PIOS_SBUS_ResetState(&(sbus_dev->state));
*sbus_id = (uint32_t)sbus_dev;
/* Enable inverter clock and enable the inverter */
(*cfg->gpio_clk_func)(cfg->gpio_clk_periph, ENABLE);
GPIO_Init(cfg->inv.gpio, &cfg->inv.init);
GPIO_WriteBit(cfg->inv.gpio, cfg->inv.init.GPIO_Pin, cfg->gpio_inv_enable);
/* Set comm driver callback */
(driver->bind_rx_cb)(lower_id, PIOS_SBUS_RxInCallback, *sbus_id);
if (!PIOS_RTC_RegisterTickCallback(PIOS_SBUS_Supervisor, *sbus_id)) {
PIOS_DEBUG_Assert(0);
}
return 0;
out_fail:
return -1;
}
/**
* unroll_channels() function computes channel_data[] from received_data[]
* Get the value of an input channel
* \param[in] channel Number of the channel desired (zero based)
* \output PIOS_RCVR_INVALID channel not available
* \output PIOS_RCVR_TIMEOUT failsafe condition or missing receiver
* \output >0 channel value
*/
static int32_t PIOS_SBUS_Get(uint32_t rcvr_id, uint8_t channel)
{
struct pios_sbus_dev *sbus_dev = (struct pios_sbus_dev *)rcvr_id;
if (!PIOS_SBUS_Validate(sbus_dev))
return PIOS_RCVR_INVALID;
/* return error if channel is not available */
if (channel >= PIOS_SBUS_NUM_INPUTS) {
return PIOS_RCVR_INVALID;
}
return sbus_dev->state.channel_data[channel];
}
/**
* Compute channel_data[] from received_data[].
* For efficiency it unrolls first 8 channels without loops and does the
* same for other 8 channels. Also 2 discrete channels will be set.
*/
static void unroll_channels(void)
static void PIOS_SBUS_UnrollChannels(struct pios_sbus_state *state)
{
uint8_t *s = received_data;
uint16_t *d = channel_data;
uint8_t *s = state->received_data;
uint16_t *d = state->channel_data;
#define F(v,s) ((v) >> s) & 0x7ff
#define F(v,s) (((v) >> (s)) & 0x7ff)
/* unroll channels 1-8 */
*d++ = F(s[0] | s[1] << 8, 0);
@ -98,111 +220,82 @@ static void unroll_channels(void)
*d++ = (s[22] & SBUS_FLAG_DC2) ? SBUS_VALUE_MAX : SBUS_VALUE_MIN;
}
/**
* process_byte() function processes incoming byte from S.Bus stream
*/
static void process_byte(uint8_t b)
/* Update decoder state processing input byte from the S.Bus stream */
static void PIOS_SBUS_UpdateState(struct pios_sbus_state *state, uint8_t b)
{
static uint8_t byte_count;
if (frame_found == 0) {
if (state->frame_found == 0) {
/* no frame found yet, waiting for start byte */
if (b == SBUS_SOF_BYTE) {
byte_count = 0;
frame_found = 1;
state->byte_count = 0;
state->frame_found = 1;
}
} else {
/* do not store start and end of frame bytes */
if (byte_count < SBUS_FRAME_LENGTH - 2) {
if (state->byte_count < SBUS_FRAME_LENGTH - 2) {
/* store next byte */
received_data[byte_count++] = b;
state->received_data[state->byte_count++] = b;
} else {
if (b == SBUS_EOF_BYTE) {
/* full frame received */
uint8_t flags = received_data[SBUS_FRAME_LENGTH - 3];
uint8_t flags = state->received_data[SBUS_FRAME_LENGTH - 3];
if (flags & SBUS_FLAG_FL) {
/* frame lost, do not update */
} else if (flags & SBUS_FLAG_FS) {
/* failsafe flag active */
reset_channels();
PIOS_SBUS_ResetChannels(state);
} else {
/* data looking good */
unroll_channels();
failsafe_timer = 0;
PIOS_SBUS_UnrollChannels(state);
state->failsafe_timer = 0;
}
} else {
/* discard whole frame */
}
/* prepare for the next frame */
frame_found = 0;
state->frame_found = 0;
}
}
}
static uint16_t PIOS_SBUS_RxInCallback(uint32_t context, uint8_t * buf, uint16_t buf_len, uint16_t * headroom, bool * need_yield)
/* Comm byte received callback */
static uint16_t PIOS_SBUS_RxInCallback(uint32_t context,
uint8_t *buf,
uint16_t buf_len,
uint16_t *headroom,
bool *need_yield)
{
struct pios_sbus_dev *sbus_dev = (struct pios_sbus_dev *)context;
bool valid = PIOS_SBUS_Validate(sbus_dev);
PIOS_Assert(valid);
struct pios_sbus_state *state = &(sbus_dev->state);
/* process byte(s) and clear receive timer */
for (uint8_t i = 0; i < buf_len; i++) {
process_byte(buf[i]);
receive_timer = 0;
PIOS_SBUS_UpdateState(state, buf[i]);
state->receive_timer = 0;
}
/* Always signal that we can accept another byte */
if (headroom) {
if (headroom)
*headroom = SBUS_FRAME_LENGTH;
}
/* We never need a yield */
*need_yield = false;
/* Always indicate that all bytes were consumed */
return (buf_len);
}
/**
* Initialise S.Bus receiver interface
*/
int32_t PIOS_SBUS_Init(uint32_t * sbus_id, const struct pios_sbus_cfg *cfg, const struct pios_com_driver * driver, uint32_t lower_id)
{
/* Enable inverter clock and enable the inverter */
(*cfg->gpio_clk_func)(cfg->gpio_clk_periph, ENABLE);
GPIO_Init(cfg->inv.gpio, &cfg->inv.init);
GPIO_WriteBit(cfg->inv.gpio,
cfg->inv.init.GPIO_Pin,
cfg->gpio_inv_enable);
(driver->bind_rx_cb)(lower_id, PIOS_SBUS_RxInCallback, 0);
if (!PIOS_RTC_RegisterTickCallback(PIOS_SBUS_Supervisor, 0)) {
PIOS_Assert(0);
}
return (0);
}
/**
* Get the value of an input channel
* \param[in] channel Number of the channel desired (zero based)
* \output -1 channel not available
* \output >0 channel value
*/
static int32_t PIOS_SBUS_Get(uint32_t rcvr_id, uint8_t channel)
{
/* return error if channel is not available */
if (channel >= SBUS_NUMBER_OF_CHANNELS) {
return PIOS_RCVR_INVALID;
}
return channel_data[channel];
return buf_len;
}
/**
* Input data supervisor is called periodically and provides
* two functions: frame syncing and failsafe triggering.
*
* S.Bus frames come at 7ms (HS) or 14ms (FS) rate at 100000bps. RTC
* timer is running at 625Hz (1.6ms). So with divider 2 it gives
* 3.2ms pause between frames which is good for both S.Bus data rates.
* S.Bus frames come at 7ms (HS) or 14ms (FS) rate at 100000bps.
* RTC timer is running at 625Hz (1.6ms). So with divider 2 it gives
* 3.2ms pause between frames which is good for both S.Bus frame rates.
*
* Data receive function must clear the receive_timer to confirm new
* data reception. If no new data received in 100ms, we must call the
@ -210,20 +303,27 @@ static int32_t PIOS_SBUS_Get(uint32_t rcvr_id, uint8_t channel)
*/
static void PIOS_SBUS_Supervisor(uint32_t sbus_id)
{
struct pios_sbus_dev *sbus_dev = (struct pios_sbus_dev *)sbus_id;
bool valid = PIOS_SBUS_Validate(sbus_dev);
PIOS_Assert(valid);
struct pios_sbus_state *state = &(sbus_dev->state);
/* waiting for new frame if no bytes were received in 3.2ms */
if (++receive_timer > 2) {
receive_timer = 0;
frame_found = 0;
if (++state->receive_timer > 2) {
state->frame_found = 0;
state->receive_timer = 0;
}
/* activate failsafe if no frames have arrived in 102.4ms */
if (++failsafe_timer > 64) {
reset_channels();
failsafe_timer = 0;
if (++state->failsafe_timer > 64) {
PIOS_SBUS_ResetChannels(state);
state->failsafe_timer = 0;
}
}
#endif
#endif /* PIOS_INCLUDE_SBUS */
/**
* @}

9
flight/PiOS/inc/pios_sbus_priv.h
View File

@ -63,7 +63,9 @@
* S.Bus protocol provides 16 proportional and 2 discrete channels.
* Do not change unless driver code is updated accordingly.
*/
#define SBUS_NUMBER_OF_CHANNELS (16 + 2)
#if (PIOS_SBUS_NUM_INPUTS != (16+2))
#error "S.Bus protocol provides 16 proportional and 2 discrete channels"
#endif
/* Discrete channels represented as bits, provide values for them */
#define SBUS_VALUE_MIN 352
@ -81,7 +83,10 @@ struct pios_sbus_cfg {
extern const struct pios_rcvr_driver pios_sbus_rcvr_driver;
extern int32_t PIOS_SBUS_Init(uint32_t * sbus_id, const struct pios_sbus_cfg *cfg, const struct pios_com_driver * driver, uint32_t lower_id);
extern int32_t PIOS_SBUS_Init(uint32_t *sbus_id,
const struct pios_sbus_cfg *cfg,
const struct pios_com_driver *driver,
uint32_t lower_id);
#endif /* PIOS_SBUS_PRIV_H */