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STM32L4 CAN: Implementation of loopback IOCTLs

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This commit is contained in:
Sebastien Lorquet 2016-06-22 10:02:20 -06:00 committed by Gregory Nutt
parent 91b82dcae3
commit 82d746ec35
2 changed files with 101 additions and 49 deletions
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146
arch/arm/src/stm32l4/stm32l4_can.c
View File

@ -809,7 +809,7 @@ static int stm32l4_canioctl(FAR struct can_dev_s *dev, int cmd,
* Description: Set new current bit timing values
* Argument: A pointer to a read-able instance of struct
* canioc_bittiming_s in which the new bit timing
* valuesare provided.
* values are provided.
* Returned Value: Zero (OK) is returned on success. Otherwise -1
* (ERROR)is returned with the errno variable set
* to indicate thenature of the error.
@ -827,8 +827,9 @@ static int stm32l4_canioctl(FAR struct can_dev_s *dev, int cmd,
FAR const struct canioc_bittiming_s *bt =
(FAR const struct canioc_bittiming_s *)arg;
uint32_t brp;
uint32_t stm32l4_canbit_quanta;
uint32_t can_bit_quanta;
uint32_t tmp;
uint32_t regval;
DEBUGASSERT(bt != NULL);
DEBUGASSERT(bt->bt_baud < STM32L4_PCLK1_FREQUENCY);
@ -836,6 +837,8 @@ static int stm32l4_canioctl(FAR struct can_dev_s *dev, int cmd,
DEBUGASSERT(bt->bt_tseg1 > 0 && bt->bt_tseg1 <= 16);
DEBUGASSERT(bt->bt_tseg2 > 0 && bt->bt_tseg2 <= 8);
regval = stm32l4_cangetreg(priv, STM32L4_CAN_BTR_OFFSET);
/* Extract bit timing data */
/* tmp is in clocks per bit time */
@ -843,35 +846,13 @@ static int stm32l4_canioctl(FAR struct can_dev_s *dev, int cmd,
/* This value is dynamic as requested by user */
stm32l4_canbit_quanta = bt->bt_tseg1 + bt->bt_tseg2 + 1;
can_bit_quanta = bt->bt_tseg1 + bt->bt_tseg2 + 1;
if (tmp < stm32l4_canbit_quanta)
if (tmp < can_bit_quanta)
{
#if 0
/* At the smallest brp value (1), there are already too few
* bit times (PCLK1 / baud) to meet our goal. brp must be one
* and we need make some reasonable guesses about ts1 and ts2.
*/
/* This timing is not possible */
brp = 1;
/* In this case, we have to guess a good value for ts1 and ts2 */
tseg1 = (tmp - 1) >> 1; /* cut available time in half */
tseg2 = tmp - tseg1 - 1; /* ts2 uses the rest minus one */
/* if we can, try to approximate the CAN requirements,
* which are not exactly "cut baud time in half"
*/
if (tseg1 == tseg2 && tseg1 > 1 && tseg2 < CAN_BTR_TSEG2_MAX)
{
tseg1--;
tseg2++;
}
#else
ret = -EINVAL;
#endif
}
/* Otherwise, nquanta is stm32l4_canbit_quanta, ts1 and ts2 are
@ -881,31 +862,21 @@ static int stm32l4_canioctl(FAR struct can_dev_s *dev, int cmd,
else
{
brp = (tmp + (stm32l4_canbit_quanta/2)) / stm32l4_canbit_quanta;
brp = (tmp + (can_bit_quanta/2)) / can_bit_quanta;
DEBUGASSERT(brp >= 1 && brp <= CAN_BTR_BRP_MAX);
}
caninfo("TS1: %d TS2: %d BRP: %d\n", bt->bt_tseg1, bt->bt_tseg2, brp);
/* Configure bit timing. This also does the following, less obvious
* things. Unless loopback mode is enabled, it:
*
* - Disables silent mode.
* - Disables loopback mode.
*
*/
/* Configure bit timing. */
tmp = ((brp - 1) << CAN_BTR_BRP_SHIFT) |
((bt->bt_tseg1 - 1) << CAN_BTR_TS1_SHIFT) |
((bt->bt_tseg2 - 1) << CAN_BTR_TS2_SHIFT) |
((bt->bt_sjw - 1) << CAN_BTR_SJW_SHIFT);
#ifdef CONFIG_CAN_LOOPBACK
tmp |= CAN_BTR_LBKM;
#endif
/* Bit timing can only be configured in init mode.
* No registers are changed.
*/
regval &= ~(CAN_BTR_BRP_MASK | CAN_BTR_TS1_MASK | CAN_BTR_TS2_MASK | CAN_BTR_SJW_MASK);
regval |= ((brp - 1) << CAN_BTR_BRP_SHIFT) |
((bt->bt_tseg1 - 1) << CAN_BTR_TS1_SHIFT) |
((bt->bt_tseg2 - 1) << CAN_BTR_TS2_SHIFT) |
((bt->bt_sjw - 1) << CAN_BTR_SJW_SHIFT);
/* Bit timing can only be configured in init mode. */
ret = stm32l4_canenterinitmode(priv);
if (ret != 0)
@ -913,7 +884,8 @@ static int stm32l4_canioctl(FAR struct can_dev_s *dev, int cmd,
break;
}
stm32l4_canputreg(priv, STM32L4_CAN_BTR_OFFSET, tmp);
stm32l4_canputreg(priv, STM32L4_CAN_BTR_OFFSET, regval);
ret = stm32l4_canexitinitmode(priv);
if (ret == 0)
@ -923,6 +895,86 @@ static int stm32l4_canioctl(FAR struct can_dev_s *dev, int cmd,
}
break;
/* CANIOC_GET_CONNMODES:
* Description: Get the current bus connection modes
* Argument: A pointer to a write-able instance of struct
* canioc_connmodes_s in which the new bus modes will
* be returned.
* Returned Value: Zero (OK) is returned on success. Otherwise -1
* (ERROR)is returned with the errno variable set
* to indicate the nature of the error.
* Dependencies: None
*/
case CANIOC_GET_CONNMODES:
{
FAR struct canioc_connmodes_s *bm =
(FAR struct canioc_connmodes_s *)arg;
uint32_t regval;
DEBUGASSERT(bm != NULL);
regval = stm32l4_cangetreg(priv, STM32L4_CAN_BTR_OFFSET);
bm->bm_loopback = ((regval & CAN_BTR_LBKM) == CAN_BTR_LBKM);
bm->bm_silent = ((regval & CAN_BTR_SILM) == CAN_BTR_SILM);
ret = OK;
break;
}
/* CANIOC_SET_CONNMODES:
* Description: Set new bus connection modes values
* Argument: A pointer to a read-able instance of struct
* canioc_connmodes_s in which the new bus modes
* are provided.
* Returned Value: Zero (OK) is returned on success. Otherwise -1
* (ERROR) is returned with the errno variable set
* to indicate the nature of the error.
* Dependencies: None
*/
case CANIOC_SET_CONNMODES:
{
FAR struct canioc_connmodes_s *bm =
(FAR struct canioc_connmodes_s *)arg;
uint32_t regval;
DEBUGASSERT(bm != NULL);
regval = stm32l4_cangetreg(priv, STM32L4_CAN_BTR_OFFSET);
if (bm->bm_loopback)
{
regval |= CAN_BTR_LBKM;
}
else
{
regval &= ~CAN_BTR_LBKM;
}
if (bm->bm_silent)
{
regval |= CAN_BTR_SILM;
}
else
{
regval &= ~CAN_BTR_SILM;
}
/* This register can only be configured in init mode. */
ret = stm32l4_canenterinitmode(priv);
if (ret != 0)
{
break;
}
stm32l4_canputreg(priv, STM32L4_CAN_BTR_OFFSET, regval);
ret = stm32l4_canexitinitmode(priv);
}
break;
#ifdef CONFIG_CAN_EXTID
/* CANIOC_ADD_EXTFILTER:
* Description: Add an address filter for a extended 29 bit

4
include/nuttx/can.h
View File

@ -192,8 +192,8 @@
#define CANIOC_ADD_EXTFILTER _CANIOC(5)
#define CANIOC_DEL_STDFILTER _CANIOC(6)
#define CANIOC_DEL_EXTFILTER _CANIOC(7)
#define CANIOC_GET_CONNMODE _CANIOC(8)
#define CANIOC_SET_CONNMODE _CANIOC(9)
#define CANIOC_GET_CONNMODES _CANIOC(8)
#define CANIOC_SET_CONNMODES _CANIOC(9)
/* CANIOC_USER: Device specific ioctl calls can be supported with cmds greater
* than this value