Author: imp
Date: Sat Aug 11 05:12:46 2012
New Revision: 239189
URL: http://svn.freebsd.org/changeset/base/239189
Log:
Update comments about setting PLLA and refernce the tables in the
datasheet that express the limits.
Modified:
head/sys/arm/at91/at91sam9260.c
Modified: head/sys/arm/at91/at91sam9260.c
==============================================================================
--- head/sys/arm/at91/at91sam9260.c Sat Aug 11 05:03:30 2012
(r239188)
+++ head/sys/arm/at91/at91sam9260.c Sat Aug 11 05:12:46 2012
(r239189)
@@ -122,21 +122,30 @@ static const struct cpu_devs at91_devs[]
{ 0, 0, 0, 0, 0 }
};
+/*
+ * The following is unused currently since we don't ever set the PLLA
+ * frequency of the device.
+ */
static uint32_t
at91_pll_outa(int freq)
{
+ uint32_t outa = 0;
- if (freq > 195000000)
- return (0x20000000);
- else
- return (0x20008000);
+ /*
+ * Set OUTA, per the data sheet. See Table 40-15 titled
+ * PLLA Characteristics in the SAM9260 doc.
+ */
+
+ if (freq > 155000000)
+ outa = 2 << 14;
+ return ((1 << 29) | outa);
}
static uint32_t
at91_pll_outb(int freq)
{
- return (0x4000);
+ return (1 << 14);
}
static void
@@ -173,7 +182,7 @@ at91_clock_init(void)
* to be near the optimal 2 MHz per datasheet. We know
* we are going to be using this for the USB clock at 96 MHz.
* Causes no extra frequency deviation for all recomended crystal
- * values.
+ * values. See Note 1, table 40-16 SAM9260 doc.
*/
clk = at91_pmc_clock_ref("pllb");
clk->pll_min_in = SAM9260_PLL_B_MIN_IN_FREQ; /* 1 MHz */
_______________________________________________
svn-src-all@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
