[U-Boot] [PATCH v3 2/4] at91: clock: remove chip macro for plla div2.

Josh Wu josh.wu at atmel.com
Mon Mar 25 08:32:07 CET 2013


at91sam9x5, at91sam9n12, at91sam9g45/m10g45 has plla div2 bits. For other
at91 arm926ejs chips, this plla div2 bits (bit-12 in mckr) is reserved and
default value after reset is 0. So we can handle all the chip in a same way.

now we can simply remove the chip select macro.

This patch also changes the div2 code to a more readable format.

Signed-off-by: Josh Wu <josh.wu at atmel.com>
---
 arch/arm/cpu/arm926ejs/at91/clock.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/arm/cpu/arm926ejs/at91/clock.c b/arch/arm/cpu/arm926ejs/at91/clock.c
index f825388..b6fd2ef 100644
--- a/arch/arm/cpu/arm926ejs/at91/clock.c
+++ b/arch/arm/cpu/arm926ejs/at91/clock.c
@@ -155,11 +155,12 @@ int at91_clock_init(unsigned long main_clock)
 	 * For now, assume this parentage won't change.
 	 */
 	mckr = readl(&pmc->mckr);
-#if defined(CONFIG_AT91SAM9G45) || defined(CONFIG_AT91SAM9M10G45) \
-		|| defined(CONFIG_AT91SAM9X5)
-	/* plla divisor by 2 */
-	gd->arch.plla_rate_hz /= (1 << ((mckr & 1 << 12) >> 12));
-#endif
+
+	/* plla divisor by 2, Only for AT91SAM9G45, 9M10G45, 9X5, 9N12 */
+	/* For other AT91 chip, the bit 12 of MCKR is reserved, default is 0 */
+	if (mckr & (1 << 12))
+		gd->arch.plla_rate_hz >>= 1;
+
 	gd->arch.mck_rate_hz = at91_css_to_rate(mckr & AT91_PMC_MCKR_CSS_MASK);
 	freq = gd->arch.mck_rate_hz;
 
-- 
1.7.9.5



More information about the U-Boot mailing list