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SAMA5 SCK: The SAMA5D3 does things a little differently

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This commit is contained in:
Gregory Nutt 2014-07-19 13:55:53 -06:00
parent d8f85d1caa
commit 6ece3d8378
1 changed files with 34 additions and 1 deletions
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35
arch/arm/src/sama5/sam_sckc.c
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@ -92,7 +92,39 @@ void sam_sckc_enable(bool enable)
{
uint32_t regval;
/* Enable / disable the slow clock */
#ifdef ATSAMA5D3
/* REVISIT: Missing the logic that disables the external OSC32 */
/* Enable external OSC 32 kHz */
regval = getreg32(SAM_SCKC_CR);
regval |= SCKC_CR_OSC32EN;
putreg32(regval, SAM_SCKC_CR);
/* Wait 5 slow clock cycles for clock stabilization */
up_udelay(5 * USEC_PER_SEC / BOARD_SLOWCLK_FREQUENCY);
/* Disable OSC 32 kHz bypass */
regval &= ~SCKC_CR_OSC32BYP;
putreg32(regval, SAM_SCKC_CR);
/* Switch slow clock source to external OSC 32 kHz (*/
regval |= SCKC_CR_OSCSEL;
putreg32(regval, SAM_SCKC_CR);
/* Wait 5 slow clock cycles for internal resynchronization */
up_udelay(5 * USEC_PER_SEC / BOARD_SLOWCLK_FREQUENCY);
/* Disable internal RC 32 kHz */
regval &= ~SCKC_CR_RCEN;
putreg32(regval, SAM_SCKC_CR);
#else
/* Switch slow clock source to external OSC 32 kHz */
regval = enable ? SCKC_CR_OSCSEL : 0;
putreg32(regval, SAM_SCKC_CR);
@ -100,4 +132,5 @@ void sam_sckc_enable(bool enable)
/* Wait 5 slow clock cycles for internal resynchronization */
up_udelay(5 * USEC_PER_SEC / BOARD_SLOWCLK_FREQUENCY);
#endif
}