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SAMV71 QSPI: Changes resulting removing of clocking

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This commit is contained in:
Gregory Nutt 2015-08-29 18:53:27 -06:00
parent b94eef2f19
commit b6515bbd4d
2 changed files with 37 additions and 17 deletions
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8
arch/arm/src/samv7/Kconfig
View File

@ -632,6 +632,14 @@ endmenu # SPI device driver options
menu "QSPI Device Driver Configuration" menu "QSPI Device Driver Configuration"
depends on SAMV7_QSPI && !SAMV7_QSPI_IS_SPI depends on SAMV7_QSPI && !SAMV7_QSPI_IS_SPI
config SAMV7_QSPI_DLYBS
int "Delay Before QSCK (uS)"
default 2
config SAMV7_QSPI_DLYBCT
int "Delay Between Consecutive Transfers (uS)"
default 5
config SAMV7_QSPI_DMA config SAMV7_QSPI_DMA
bool "QSPI DMA" bool "QSPI DMA"
default n default n

46
arch/arm/src/samv7/sam_qspi.c
View File

@ -75,6 +75,15 @@
* Pre-processor Definitions * Pre-processor Definitions
****************************************************************************/ ****************************************************************************/
/* Configuration ************************************************************/ /* Configuration ************************************************************/
#ifndef CONFIG_SAMV7_QSPI_DLYBS
# define CONFIG_SAMV7_QSPI_DLYBS 2
#endif
#ifndef CONFIG_SAMV7_QSPI_DLYBCT
# define CONFIG_SAMV7_QSPI_DLYBCT 5
#endif
/* When QSPI DMA is enabled, small DMA transfers will still be performed by /* When QSPI DMA is enabled, small DMA transfers will still be performed by
* polling logic. But we need a threshold value to determine what is small. * polling logic. But we need a threshold value to determine what is small.
* That value is provided by CONFIG_SAMV7_QSPI_DMATHRESHOLD. * That value is provided by CONFIG_SAMV7_QSPI_DMATHRESHOLD.
@ -1082,41 +1091,44 @@ static uint32_t qspi_setfrequency(struct qspi_dev_s *dev, uint32_t frequency)
/* Configure QSPI to a frequency as close as possible to the requested frequency. /* Configure QSPI to a frequency as close as possible to the requested frequency.
* *
* SPCK frequency = QSPI_CLK / SCBR, or SCBR = QSPI_CLK / frequency * QSCK frequency = QSPI_CLK / SCBR, or SCBR = QSPI_CLK / frequency
*
* Where SCBR can have the range 1 to 256 and register holds SCBR - 1
*/ */
scbr = SAM_QSPI_CLOCK / frequency; scbr = SAM_QSPI_CLOCK / frequency;
if (scbr < 8) /* Make sure that the divider is within range */
if (scbr < 1)
{ {
scbr = 8; scbr = 1;
} }
else if (scbr > 254) else if (scbr > 256)
{ {
scbr = 254; scbr = 256;
} }
scbr = (scbr + 1) & ~1; /* Save the new SCBR value (minus one) */
/* Save the new SCBR value */
regval = qspi_getreg(priv, SAM_QSPI_SCR_OFFSET); regval = qspi_getreg(priv, SAM_QSPI_SCR_OFFSET);
regval &= ~(QSPI_SCR_SCBR_MASK | QSPI_SCR_DLYBS_MASK); regval &= ~(QSPI_SCR_SCBR_MASK | QSPI_SCR_DLYBS_MASK);
regval |= scbr << QSPI_SCR_SCBR_SHIFT; regval |= (scbr - 1) << QSPI_SCR_SCBR_SHIFT;
/* DLYBS: Delay Before SPCK. This field defines the delay from NPCS valid to the /* DLYBS: Delay Before QSCK. This field defines the delay from NPCS valid to the
* first valid SPCK transition. When DLYBS equals zero, the NPCS valid to SPCK * first valid QSCK transition. When DLYBS equals zero, the NPCS valid to QSCK
* transition is 1/2 the SPCK clock period. Otherwise, the following equations * transition is 1/2 the QSCK clock period. Otherwise, the following equations
* determine the delay: * determine the delay:
* *
* Delay Before SPCK = DLYBS / QSPI_CLK * Delay Before QSCK = DLYBS / QSPI_CLK
* *
* For a 2uS delay * For a 2uS delay
* *
* DLYBS = QSPI_CLK * 0.000002 = QSPI_CLK / 500000 * DLYBS == 2 * QSPI_CLK / 1000000
*/ */
dlybs = SAM_QSPI_CLOCK / 500000; dlybs = (CONFIG_SAMV7_QSPI_DLYBS * SAM_QSPI_CLOCK) / 1000000;
regval |= dlybs << QSPI_SCR_DLYBS_SHIFT; regval |= dlybs << QSPI_SCR_DLYBS_SHIFT;
qspi_putreg(priv, regval, SAM_QSPI_SCR_OFFSET); qspi_putreg(priv, regval, SAM_QSPI_SCR_OFFSET);
@ -1129,10 +1141,10 @@ static uint32_t qspi_setfrequency(struct qspi_dev_s *dev, uint32_t frequency)
* *
* For a 5uS delay: * For a 5uS delay:
* *
* DLYBCT = QSPI_CLK * 0.000005 / 32 = QSPI_CLK / 200000 / 32 * DLYBCT = 5 * QSPI_CLK * 1000000 / 32
*/ */
dlybct = SAM_QSPI_CLOCK / 200000 / 32; dlybct = (CONFIG_SAMV7_QSPI_DLYBCT * SAM_QSPI_CLOCK) / 1000000 / 32;
regval = qspi_getreg(priv, SAM_QSPI_MR_OFFSET); regval = qspi_getreg(priv, SAM_QSPI_MR_OFFSET);
regval &= ~QSPI_MR_DLYBCT_MASK; regval &= ~QSPI_MR_DLYBCT_MASK;