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SAMA5 TWI: If running from SDRAM, BOARD_MCK_FREQUENCY is not a constant and cannot be used in pre-processor conditionals

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This commit is contained in:
Gregory Nutt 2014-04-16 12:09:55 -06:00
parent 67bea2d342
commit 044f7209f6
1 changed files with 36 additions and 26 deletions
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58
arch/arm/src/sama5/sam_twi.c
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@ -99,22 +99,6 @@
#define TWI_MAX_FREQUENCY 66000000 /* Maximum TWI frequency */
#if BOARD_MCK_FREQUENCY <= TWI_MAX_FREQUENCY
# define TWI_FREQUENCY BOARD_MCK_FREQUENCY
# define TWI_PCR_DIV PMC_PCR_DIV1
#elif (BOARD_MCK_FREQUENCY >> 1) <= TWI_MAX_FREQUENCY
# define TWI_FREQUENCY (BOARD_MCK_FREQUENCY >> 1)
# define TWI_PCR_DIV PMC_PCR_DIV2
#elif (BOARD_MCK_FREQUENCY >> 2) <= TWI_MAX_FREQUENCY
# define TWI_FREQUENCY (BOARD_MCK_FREQUENCY >> 2)
# define TWI_PCR_DIV PMC_PCR_DIV4
#elif (BOARD_MCK_FREQUENCY >> 3) <= TWI_MAX_FREQUENCY
# define TWI_FREQUENCY (BOARD_MCK_FREQUENCY >> 3)
# define TWI_PCR_DIV PMC_PCR_DIV8
#else
# error Cannot realize TWI frequency
#endif
/* Debug ***********************************************************************/
/* CONFIG_DEBUG_I2C + CONFIG_DEBUG enables general I2C debug output. */
@ -139,6 +123,7 @@ struct twi_dev_s
struct i2c_dev_s dev; /* Generic I2C device */
struct i2c_msg_s *msg; /* Message list */
uintptr_t base; /* Base address of registers */
uint32_t frequency; /* TWO clock frequency */
uint16_t irq; /* IRQ number for this device */
uint16_t address; /* Slave address */
uint16_t flags; /* Transfer flags */
@ -277,7 +262,7 @@ struct i2c_ops_s g_twiops =
* Name: twi_takesem
*
* Description:
* Take the wait semaphore (handling false alarm wakeups due to the receipt
* Take the wait semaphore (handling false alarm wake-ups due to the receipt
* of signals).
*
* Input Parameters:
@ -314,7 +299,7 @@ static void twi_takesem(sem_t *sem)
*
* Returned Value:
* true: This is the first register access of this type.
* flase: This is the same as the preceding register access.
* false: This is the same as the preceding register access.
*
****************************************************************************/
@ -504,7 +489,6 @@ static int twi_interrupt(struct twi_dev_s *priv)
uint32_t imr;
uint32_t pending;
uint32_t regval;
int ret;
/* Retrieve masked interrupt status */
@ -580,9 +564,8 @@ static int twi_interrupt(struct twi_dev_s *priv)
else if ((pending & TWI_INT_TXCOMP) != 0)
{
twi_putrel(priv, SAM_TWI_IDR_OFFSET, TWI_INT_TXCOMP);
ret = OK;
/* Is there another messasge to send? */
/* Is there another message to send? */
if (priv->msgc > 1)
{
@ -1096,7 +1079,7 @@ static uint32_t twi_hw_setfrequency(struct twi_dev_s *priv, uint32_t frequency)
{
/* Calulate the CLDIV value using the current CKDIV guess */
cldiv = ((TWI_FREQUENCY / (frequency << 1)) - 4) / (1 << ckdiv);
cldiv = ((priv->frequency / (frequency << 1)) - 4) / (1 << ckdiv);
/* Is CLDIV in range? */
@ -1121,7 +1104,7 @@ static uint32_t twi_hw_setfrequency(struct twi_dev_s *priv, uint32_t frequency)
/* Return the actual frequency */
actual = (TWI_FREQUENCY / 2) / (((1 << ckdiv) * cldiv) + 2);
actual = (priv->frequency / 2) / (((1 << ckdiv) * cldiv) + 2);
i2cvdbg("TWI%d frequency: %d ckdiv: %d cldiv: %d actual: %d\n",
priv->twi, frequency, ckdiv, cldiv, actual);
@ -1140,6 +1123,7 @@ static void twi_hw_initialize(struct twi_dev_s *priv, unsigned int pid,
uint32_t frequency)
{
uint32_t regval;
uint32_t mck;
i2cvdbg("TWI%d Initializing\n", priv->twi);
@ -1161,9 +1145,35 @@ static void twi_hw_initialize(struct twi_dev_s *priv, unsigned int pid,
twi_putrel(priv, SAM_TWI_CR_OFFSET, TWI_CR_MSEN);
/* Determine the maximum valid frequency setting */
mck = BOARD_MCK_FREQUENCY;
DEBUGASSERT((mck >> 3) <= TWI_MAX_FREQUENCY);
if (mck <= TWI_MAX_FREQUENCY)
{
priv->frequency = mck;
regval = PMC_PCR_DIV1;
}
else if ((mck >> 1) <= TWI_MAX_FREQUENCY)
{
priv->frequency = (mck >> 1);
regval = PMC_PCR_DIV2;
}
else if ((mck >> 2) <= TWI_MAX_FREQUENCY)
{
priv->frequency = (mck >> 2);
regval = PMC_PCR_DIV4;
}
else /* if ((mck >> 3) <= TWI_MAX_FREQUENCY) */
{
priv->frequency = (mck >> 3);
regval = PMC_PCR_DIV8;
}
/* Set the TWI peripheral input clock to the maximum, valid frequency */
regval = PMC_PCR_PID(pid) | PMC_PCR_CMD | TWI_PCR_DIV | PMC_PCR_EN;
regval |= PMC_PCR_PID(pid) | PMC_PCR_CMD | PMC_PCR_EN;
twi_putabs(priv, SAM_PMC_PCR, regval);
/* Set the initial TWI data transfer frequency */