diff --git a/ChangeLog b/ChangeLog
index 5728ceccabe4761a596675b63e36ac89faeb99e5..57eaf7a996469ba03e903ffe7026d658dfee6b8d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2070,3 +2070,7 @@
temperature sensor driver.
* configs/stm3210e-eval/src/up_lm75.c: Add support for the LM-75 on the
STMicro STM3210E-EVAL board.
+ * sched/clock_gettime.c: Correct an error in the tv_nsec calculation
+ that happens only config CONFIG_RTC is enabled.
+ * arch/arm/src/stm32/stm32_i2c.c: Correct some bugs related to waiting
+ to the I2C STOP condition to be cleared.
diff --git a/arch/arm/src/stm32/stm32_i2c.c b/arch/arm/src/stm32/stm32_i2c.c
index 15f22e602b6fd0c652ea76471ab39143af7925ae..dd551bf3b1039756a22fe809e0e2b65d51f74aa2 100644
--- a/arch/arm/src/stm32/stm32_i2c.c
+++ b/arch/arm/src/stm32/stm32_i2c.c
@@ -429,12 +429,25 @@ static inline void stm32_i2c_sendstart(FAR struct stm32_i2c_priv_s *priv)
static inline void stm32_i2c_clrstart(FAR struct stm32_i2c_priv_s *priv)
{
- /* "This [START] bit is set and cleared by software and cleared by hardware
+ /* "Note: When the STOP, START or PEC bit is set, the software must
+ * not perform any write access to I2C_CR1 before this bit is
+ * cleared by hardware. Otherwise there is a risk of setting a
+ * second STOP, START or PEC request."
+ *
+ * "The [STOP] bit is set and cleared by software, cleared by hardware
+ * when a Stop condition is detected, set by hardware when a timeout
+ * error is detected.
+ *
+ * "This [START] bit is set and cleared by software and cleared by hardware
* when start is sent or PE=0." The bit must be cleared by software if the
* START is never sent.
+ *
+ * "This [PEC] bit is set and cleared by software, and cleared by hardware
+ * when PEC is transferred or by a START or Stop condition or when PE=0."
*/
- stm32_i2c_modifyreg(priv, STM32_I2C_CR1_OFFSET, I2C_CR1_START, 0);
+ stm32_i2c_modifyreg(priv, STM32_I2C_CR1_OFFSET,
+ I2C_CR1_START|I2C_CR1_STOP|I2C_CR1_PEC, 0);
}
static inline void stm32_i2c_sendstop(FAR struct stm32_i2c_priv_s *priv)
@@ -871,6 +884,7 @@ int stm32_i2c_process(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, int
struct stm32_i2c_inst_s *inst = (struct stm32_i2c_inst_s *)dev;
uint32_t status = 0;
uint32_t ahbenr;
+ uint16_t regval;
int status_errno = 0;
ASSERT(count);
@@ -879,15 +893,43 @@ int stm32_i2c_process(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, int
ahbenr = stm32_i2c_disablefsmc(inst->priv);
- /* Wait as stop might still be in progress
- *
- * \todo GET RID OF THIS PERFORMANCE LOSS and for() loop
+ /* Wait as stop might still be in progress; but stop might also
+ * be set because of a timeout error: "The [STOP] bit is set and
+ * cleared by software, cleared by hardware when a Stop condition is
+ * detected, set by hardware when a timeout error is detected."
*/
-
- for (; stm32_i2c_getreg(inst->priv, STM32_I2C_CR1_OFFSET) & I2C_CR1_STOP; )
+
+ for (;;)
{
- up_waste();
+ /* Check for STOP condition */
+
+ regval = stm32_i2c_getreg(inst->priv, STM32_I2C_CR1_OFFSET);
+ if ((regval & I2C_CR1_STOP) == 0)
+ {
+ break;
+ }
+
+ /* Check for timeout error */
+
+ regval = stm32_i2c_getreg(inst->priv, STM32_I2C_SR1_OFFSET);
+ if ((regval & I2C_SR1_TIMEOUT) != 0)
+ {
+ break;
+ }
}
+
+ /* Clear any pending error interrupts */
+
+ stm32_i2c_putreg(inst->priv, STM32_I2C_SR1_OFFSET, 0);
+
+ /* "Note: When the STOP, START or PEC bit is set, the software must
+ * not perform any write access to I2C_CR1 before this bit is
+ * cleared by hardware. Otherwise there is a risk of setting a
+ * second STOP, START or PEC request." However, if the bits are
+ * not cleared by hardware, then we will have to do that from hardware.
+ */
+
+ stm32_i2c_clrstart(inst->priv);
/* Old transfers are done */
@@ -898,10 +940,6 @@ int stm32_i2c_process(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, int
stm32_i2c_setclock(inst->priv, inst->frequency);
- /* Clear any pending error interrupts */
-
- stm32_i2c_putreg(inst->priv, STM32_I2C_SR1_OFFSET, 0);
-
/* Trigger start condition, then the process moves into the ISR. I2C
* interrupts will be enabled within stm32_i2c_waitisr().
*/
@@ -917,10 +955,10 @@ int stm32_i2c_process(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, int
status = stm32_i2c_getstatus(inst->priv);
status_errno = ETIMEDOUT;
- /* " Note: When the STOP, START or PEC bit is set, the software must
- * not perform any write access to I2C_CR1 before this bit is
- * cleared by hardware. Otherwise there is a risk of setting a
- * second STOP, START or PEC request."
+ /* "Note: When the STOP, START or PEC bit is set, the software must
+ * not perform any write access to I2C_CR1 before this bit is
+ * cleared by hardware. Otherwise there is a risk of setting a
+ * second STOP, START or PEC request."
*/
stm32_i2c_clrstart(inst->priv);
@@ -936,6 +974,8 @@ int stm32_i2c_process(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, int
if ((status & I2C_SR1_ERRORMASK) != 0)
{
+ /* I2C_SR1_ERRORMASK is the 'OR' of the following individual bits: */
+
if (status & I2C_SR1_BERR)
{
/* Bus Error */
@@ -975,7 +1015,7 @@ int stm32_i2c_process(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, int
/* This is not an error and should never happen since SMBus is not enabled */
- else if (status & I2C_SR1_SMBALERT)
+ else /* if (status & I2C_SR1_SMBALERT) */
{
/* SMBus alert is an optional signal with an interrupt line for devices
* that want to trade their ability to master for a pin.
@@ -987,9 +1027,11 @@ int stm32_i2c_process(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs, int
/* This is not an error, but should not happen. The BUSY signal can hang,
* however, if there are unhealthy devices on the bus that need to be reset.
+ * NOTE: We will only see this buy indication if stm32_i2c_sem_waitisr()
+ * fails above; Otherwise it is cleared.
*/
- else if (status & (I2C_SR2_BUSY << 16))
+ else if ((status & (I2C_SR2_BUSY << 16)) != 0)
{
/* I2C Bus is for some reason busy */
@@ -1016,7 +1058,7 @@ int stm32_i2c_write(FAR struct i2c_dev_s *dev, const uint8_t *buffer, int buflen
.buffer = (uint8_t *)buffer,
.length = buflen
};
-
+
return stm32_i2c_process(dev, &msgv, 1);
}
diff --git a/configs/stm3210e-eval/README.txt b/configs/stm3210e-eval/README.txt
index 772020e96021c4183314ea7b7faf908a45ab93ec..b63f7c5f29323b99391ce8064e36d415cc83086c 100755
--- a/configs/stm3210e-eval/README.txt
+++ b/configs/stm3210e-eval/README.txt
@@ -13,6 +13,7 @@ Contents
- NuttX buildroot Toolchain
- DFU
- LEDs
+ - Temperature Sensor
- STM3210E-EVAL-specific Configuration Options
- Configurations
@@ -237,6 +238,32 @@ They are encoded as follows:
on a small proportion of the time.
*** LED2 may also flicker normally if signals are processed.
+Temperature Sensor
+==================
+
+Support for the on-board LM-75 temperature sensor is available. This supported
+has been verified, but has not been included in any of the available the
+configurations. To set up the temperature sensor, add the following to the
+NuttX configuration file
+
+ CONFIG_I2C=y
+ CONFIG_I2C_LM75=y
+
+Then you can implement logic like the following to use the temperature sensor:
+
+ #include <nuttx/sensors/lm75.h>
+ #include <arch/board/board.h>
+
+ ret = stm32_lm75initialize("/dev/temp"); /* Register the temperature sensor */
+ fd = open("/dev/temp", O_RDONLY); /* Open the temperature sensor device */
+ ret = ioctl(fd, SNIOC_FAHRENHEIT, 0); /* Select Fahrenheit */
+ bytesread = read(fd, buffer, 8*sizeof(b16_t)); /* Read temperature samples */
+
+More complex temperature sensor operations are also available. See the IOCTAL
+commands enumerated in include/nuttx/sensors/lm75.h. Also read the descriptions
+of the stm32_lm75initialize() and stm32_lm75attach() interfaces in the
+arch/board/board.h file (sames as configs/stm3210e-eval/include/board.h).
+
STM3210E-EVAL-specific Configuration Options
============================================
diff --git a/drivers/sensors/lm75.c b/drivers/sensors/lm75.c
index 600f9aab3b316faccf3be3597cc9647631ca9d26..397cb958243885d56d6c4255b4c555a1f14cf127 100644
--- a/drivers/sensors/lm75.c
+++ b/drivers/sensors/lm75.c
@@ -43,6 +43,7 @@
#include <stdlib.h>
#include <fixedmath.h>
#include <errno.h>
+#include <debug.h>
#include <nuttx/fs.h>
#include <nuttx/i2c.h>
@@ -57,7 +58,19 @@
/* Centigrade to Fahrenheit conversion: F = 9*C/5 + 32 */
#define B16_9DIV5 (9 * 65536 / 5)
-#define B16_32 (32 * 65536);
+#define B16_32 (32 * 65536)
+
+/* Debug for this file only */
+
+#ifdef CONFIG_DEBUG_LM75
+# define lm75dbg dbg
+#else
+# ifdef CONFIG_CPP_HAVE_VARARGS
+# define lm75dbg(x...)
+# else
+# define lm75dbg (void)
+# endif
+#endif
/****************************************************************************
* Private
@@ -75,14 +88,12 @@ struct lm75_dev_s
****************************************************************************/
/* I2C Helpers */
-static int lm75_readb8(FAR struct lm75_dev_s *priv, uint8_t regaddr,
- FAR b8_t *regvalue);
-#if 0 // Not used
-static int lm75_writeb8(FAR struct lm75_dev_s *priv, uint8_t regaddr,
- b8_t regval);
-#endif
-static int lm75_readtemp(FAR struct lm75_dev_s *priv, b16_t *temp);
-static int lm75_readconf(FAR struct lm75_dev_s *priv, uint8_t *conf);
+static int lm75_readb16(FAR struct lm75_dev_s *priv, uint8_t regaddr,
+ FAR b16_t *regvalue);
+static int lm75_writeb16(FAR struct lm75_dev_s *priv, uint8_t regaddr,
+ b16_t regval);
+static int lm75_readtemp(FAR struct lm75_dev_s *priv, FAR b16_t *temp);
+static int lm75_readconf(FAR struct lm75_dev_s *priv, FAR uint8_t *conf);
static int lm75_writeconf(FAR struct lm75_dev_s *priv, uint8_t conf);
/* Character driver methods */
@@ -114,15 +125,15 @@ static const struct file_operations lm75_fops =
* Private Functions
****************************************************************************/
/****************************************************************************
- * Name: lm75_readb8
+ * Name: lm75_readb16
*
* Description:
* Read a 16-bit register (LM75_TEMP_REG, LM75_THYS_REG, or LM75_TOS_REG)
*
****************************************************************************/
-static int lm75_readb8(FAR struct lm75_dev_s *priv, uint8_t regaddr,
- FAR b8_t *regvalue)
+static int lm75_readb16(FAR struct lm75_dev_s *priv, uint8_t regaddr,
+ FAR b16_t *regvalue)
{
uint8_t buffer[2];
int ret;
@@ -133,6 +144,7 @@ static int lm75_readb8(FAR struct lm75_dev_s *priv, uint8_t regaddr,
ret = I2C_WRITE(priv->i2c, ®addr, 1);
if (ret < 0)
{
+ lm75dbg("I2C_WRITE failed: %d\n", ret);
return ret;
}
@@ -141,43 +153,49 @@ static int lm75_readb8(FAR struct lm75_dev_s *priv, uint8_t regaddr,
ret = I2C_READ(priv->i2c, buffer, 2);
if (ret < 0)
{
+ lm75dbg("I2C_READ failed: %d\n", ret);
return ret;
}
- /* Data format is: TTTTTTTT Txxxxxxx where TTTTTTTTT is a nine-bit
- * temperature value with LSB = 0.5 degrees centigrade. So the raw
- * data is b8_t
+ /* Data format is: TTTTTTTT Txxxxxxx where TTTTTTTTT is a nine-bit,
+ * signed temperature value with LSB = 0.5 degrees centigrade. So the
+ * raw data is b8_t
*/
- *regvalue = (b8_t)buffer[0] << 8 | (b8_t)buffer[1];
+ *regvalue = b8tob16((b8_t)buffer[0] << 8 | (b8_t)buffer[1]);
+ lm75dbg("addr: %02x value: %08x ret: %d\n", regaddr, *regvalue, ret);
return OK;
}
/****************************************************************************
- * Name: lm75_writeb8
+ * Name: lm75_writeb16
*
* Description:
* Write to a 16-bit register (LM75_TEMP_REG, LM75_THYS_REG, or LM75_TOS_REG)
*
****************************************************************************/
-#if 0 // Not used
-static int lm75_writeb8(FAR struct lm75_dev_s *priv, uint8_t regaddr,
- b8_t regval)
+
+static int lm75_writeb16(FAR struct lm75_dev_s *priv, uint8_t regaddr,
+ b16_t regval)
{
uint8_t buffer[3];
+ b8_t regb8;
+
+ lm75dbg("addr: %02x value: %08x\n", regaddr, regval);
/* Set up a 3 byte message to send */
buffer[0] = regaddr;
- buffer[1] = regval >> 8;
- buffer[2] = regval;
+
+ regb8 = b16tob8(regval);
+ buffer[1] = (uint8_t)(regb8 >> 8);
+ buffer[2] = (uint8_t)regb8;
/* Write the register address followed by the data (no RESTART) */
I2C_SETADDRESS(priv->i2c, priv->addr, 7);
return I2C_WRITE(priv->i2c, buffer, 3);
}
-#endif
/****************************************************************************
* Name: lm75_readtemp
@@ -187,26 +205,20 @@ static int lm75_writeb8(FAR struct lm75_dev_s *priv, uint8_t regaddr,
*
****************************************************************************/
-static int lm75_readtemp(FAR struct lm75_dev_s *priv, b16_t *temp)
+static int lm75_readtemp(FAR struct lm75_dev_s *priv, FAR b16_t *temp)
{
- b8_t temp8;
b16_t temp16;
int ret;
- /* Read the raw temperature data. Data format is: TTTTTTTT Txxxxxxx where
- * TTTTTTTTT is a nine-bit temperature value with LSB = 0.5 degrees centigrade.
- * So the raw data is b8_t.
- */
-
- ret = lm75_readb8(priv, LM75_TEMP_REG, &temp8);
+ /* Read the raw temperature data (b16_t) */
+
+ ret = lm75_readb16(priv, LM75_TEMP_REG, &temp16);
if (ret < 0)
{
+ lm75dbg("lm75_readb16 failed: %d\n", ret);
return ret;
}
-
- /* Convert to b16_t */
-
- temp16 = b8tob16(temp8);
+ lm75dbg("Centigrade: %08x\n", temp16);
/* Was fahrenheit requested? */
@@ -215,6 +227,7 @@ static int lm75_readtemp(FAR struct lm75_dev_s *priv, b16_t *temp)
/* Centigrade to Fahrenheit conversion: F = 9*C/5 + 32 */
temp16 = b16mulb16(temp16, B16_9DIV5) + B16_32;
+ lm75dbg("Fahrenheit: %08x\n", temp16);
}
*temp = temp16;
@@ -229,7 +242,7 @@ static int lm75_readtemp(FAR struct lm75_dev_s *priv, b16_t *temp)
*
****************************************************************************/
-static int lm75_readconf(FAR struct lm75_dev_s *priv, uint8_t *conf)
+static int lm75_readconf(FAR struct lm75_dev_s *priv, FAR uint8_t *conf)
{
uint8_t buffer;
int ret;
@@ -242,12 +255,14 @@ static int lm75_readconf(FAR struct lm75_dev_s *priv, uint8_t *conf)
ret = I2C_WRITE(priv->i2c, &buffer, 1);
if (ret < 0)
{
+ lm75dbg("I2C_WRITE failed: %d\n", ret);
return ret;
}
/* Restart and read 8-bits from the register */
ret = I2C_READ(priv->i2c, conf, 1);
+ lm75dbg("conf: %02x ret: %d\n", *conf, ret);
return ret;
}
@@ -263,6 +278,8 @@ static int lm75_writeconf(FAR struct lm75_dev_s *priv, uint8_t conf)
{
uint8_t buffer[2];
+ lm75dbg("conf: %02x\n", conf);
+
/* Set up a 2 byte message to send */
buffer[0] = LM75_CONF_REG;
@@ -310,16 +327,19 @@ static ssize_t lm75_read(FAR struct file *filep, FAR char *buffer, size_t buflen
FAR struct lm75_dev_s *priv = inode->i_private;
FAR b16_t *ptr;
ssize_t nsamples;
+ int i;
int ret;
/* How many samples were requested to get? */
- nsamples = buflen/sizeof(b16_t);
+ nsamples = buflen / sizeof(b16_t);
ptr = (FAR b16_t *)buffer;
+ lm75dbg("buflen: %d nsamples: %d\n", buflen, nsamples);
+
/* Get the requested number of samples */
- for (; nsamples > 0; nsamples--)
+ for (i = 0; i < nsamples; i++)
{
b16_t temp;
@@ -328,6 +348,7 @@ static ssize_t lm75_read(FAR struct file *filep, FAR char *buffer, size_t buflen
ret = lm75_readtemp(priv, &temp);
if (ret < 0)
{
+ lm75dbg("lm75_readtemp failed: %d\n",ret);
return (ssize_t)ret;
}
@@ -359,7 +380,7 @@ static int lm75_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
FAR struct lm75_dev_s *priv = inode->i_private;
int ret = OK;
- switch (arg)
+ switch (cmd)
{
/* Read from the configuration register. Arg: uint8_t* pointer */
@@ -367,6 +388,7 @@ static int lm75_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR uint8_t *ptr = (FAR uint8_t *)((uintptr_t)arg);
ret = lm75_readconf(priv, ptr);
+ lm75dbg("conf: %02x ret: %d\n", *ptr, ret);
}
break;
@@ -374,6 +396,7 @@ static int lm75_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
case SNIOC_WRITECONF:
ret = lm75_writeconf(priv, (uint8_t)arg);
+ lm75dbg("conf: %02x ret: %d\n", *(uint8_t*)arg, ret);
break;
/* Shutdown the LM75, Arg: None */
@@ -386,6 +409,7 @@ static int lm75_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
ret = lm75_writeconf(priv, conf | LM75_CONF_SHUTDOWN);
}
+ lm75dbg("conf: %02x ret: %d\n", conf | LM75_CONF_SHUTDOWN, ret);
}
break;
@@ -399,6 +423,7 @@ static int lm75_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
ret = lm75_writeconf(priv, conf & ~LM75_CONF_SHUTDOWN);
}
+ lm75dbg("conf: %02x ret: %d\n", conf & ~LM75_CONF_SHUTDOWN, ret);
}
break;
@@ -406,15 +431,52 @@ static int lm75_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
case SNIOC_FAHRENHEIT:
priv->fahrenheit = true;
+ lm75dbg("Fahrenheit\n");
break;
/* Report Samples in Centigrade */
case SNIOC_CENTIGRADE:
priv->fahrenheit = false;
+ lm75dbg("Centigrade\n");
+ break;
+
+ /* Read THYS temperature register. Arg: b16_t* pointer */
+
+ case SNIOC_READTHYS:
+ {
+ FAR b16_t *ptr = (FAR b16_t *)((uintptr_t)arg);
+ ret = lm75_readb16(priv, LM75_THYS_REG, ptr);
+ lm75dbg("THYS: %08x ret: %d\n", *ptr, ret);
+ }
+ break;
+
+ /* Write THYS temperature register. Arg: b16_t value */
+
+ case SNIOC_WRITETHYS:
+ ret = lm75_writeb16(priv, LM75_THYS_REG, (b16_t)arg);
+ lm75dbg("THYS: %08x ret: %d\n", (b16_t)arg, ret);
+ break;
+
+ /* Read TOS (Over-temp Shutdown Threshold) Register. Arg: b16_t* pointer */
+
+ case SNIOC_READTOS:
+ {
+ FAR b16_t *ptr = (FAR b16_t *)((uintptr_t)arg);
+ ret = lm75_readb16(priv, LM75_TOS_REG, ptr);
+ lm75dbg("TOS: %08x ret: %d\n", *ptr, ret);
+ }
+ break;
+
+ /* Write TOS (Over-temp Shutdown Threshold) Register. Arg: b16_t value */
+
+ case SNIOC_WRITRETOS:
+ ret = lm75_writeb16(priv, LM75_TOS_REG, (b16_t)arg);
+ lm75dbg("TOS: %08x ret: %d\n", (b16_t)arg, ret);
break;
default:
+ lm75dbg("Unrecognized cmd: %d\n", cmd);
ret = -ENOTTY;
break;
}
@@ -454,6 +516,7 @@ int lm75_register(FAR const char *devpath, FAR struct i2c_dev_s *i2c, uint8_t ad
priv = (FAR struct lm75_dev_s *)malloc(sizeof(struct lm75_dev_s));
if (!priv)
{
+ lm75dbg("Failed to allocate instance\n");
return -ENOMEM;
}
@@ -466,6 +529,7 @@ int lm75_register(FAR const char *devpath, FAR struct i2c_dev_s *i2c, uint8_t ad
ret = register_driver(devpath, &lm75_fops, 0555, priv);
if (ret < 0)
{
+ lm75dbg("Failed to register driver: %d\n", ret);
free(priv);
}
return ret;
diff --git a/include/nuttx/sensors/lm75.h b/include/nuttx/sensors/lm75.h
index 54100088e7584ae19a3d74217ebb8c8cb6ac1115..0d27a586bb48f0390d09bc8e2fe9985788cfa484 100644
--- a/include/nuttx/sensors/lm75.h
+++ b/include/nuttx/sensors/lm75.h
@@ -61,6 +61,10 @@
#define SNIOC_POWERUP _SNIOC(0x0004) /* Arg: None */
#define SNIOC_FAHRENHEIT _SNIOC(0x0005) /* Arg: None */
#define SNIOC_CENTIGRADE _SNIOC(0x0006) /* Arg: None */
+#define SNIOC_READTHYS _SNIOC(0x0007) /* Arg: b16_t* pointer */
+#define SNIOC_WRITETHYS _SNIOC(0x0008) /* Arg: b16_t value */
+#define SNIOC_READTOS _SNIOC(0x0009) /* Arg: b16_t* pointer */
+#define SNIOC_WRITRETOS _SNIOC(0x000a) /* Arg: b16_t value */
/* LM-75 Register Definitions ***********************************************/
/* LM-75 Registers addresses */
@@ -68,7 +72,7 @@
#define LM75_TEMP_REG 0x00 /* Temperature Register */
#define LM75_CONF_REG 0x01 /* Configuration Register */
#define LM75_THYS_REG 0x02 /* Temperature Register */
-#define LM75_TOS_REG 0x03 /* Over-temp Shutdown threshold Register */
+#define LM75_TOS_REG 0x03 /* Over-temp Shutdown Threshold Register */
/* Configuration Register Bit Definitions */
diff --git a/sched/clock_gettime.c b/sched/clock_gettime.c
index 5f975f52b3294d825b723dd74f553bb024cdb690..3fdfe9602d17d6a7402712c76a9332cbdc061458 100644
--- a/sched/clock_gettime.c
+++ b/sched/clock_gettime.c
@@ -148,7 +148,7 @@ int clock_gettime(clockid_t clock_id, struct timespec *tp)
if (g_rtc_enabled)
{
tp->tv_sec = up_rtc_gettime();
- tp->tv_nsec = (up_rtc_getclock() & (RTC_CLOCKS_PER_SEC-1) ) * (1000000000/TICK_PER_SEC);
+ tp->tv_nsec = (up_rtc_getclock() & (RTC_CLOCKS_PER_SEC-1) ) * (1000000000/RTC_CLOCKS_PER_SEC);
}
else
#endif