[U-Boot] [PATCH 3/8] APM82xxx: Add clock speed calculations

[tmarri at apm.com]

From: Tirumala Marri <tmarri at apm.com>

This patch adds support for speed calculations for different
IP blocks, based on the bootstrap values programmed into EPROM device.

Signed-off-by: Tirumala R Marri <tmarri at apm.com>
---
 arch/powerpc/cpu/ppc4xx/speed.c |   85 ++++++++++++++++++++++++++++++++++++++-
 1 files changed, 84 insertions(+), 1 deletions(-)

diff --git a/arch/powerpc/cpu/ppc4xx/speed.c b/arch/powerpc/cpu/ppc4xx/speed.c
index 906face..b613275 100644
--- a/arch/powerpc/cpu/ppc4xx/speed.c
+++ b/arch/powerpc/cpu/ppc4xx/speed.c
@@ -189,7 +189,7 @@ ulong get_PCI_freq (void)
 #elif defined(CONFIG_440)
 
 #if defined(CONFIG_460EX) || defined(CONFIG_460GT) || \
-    defined(CONFIG_460SX)
+    defined(CONFIG_460SX) || defined(CONFIG_APM82XXX)
 static u8 pll_fwdv_multi_bits[] = {
 	/* values for:  1 - 16 */
 	0x00, 0x01, 0x0f, 0x04, 0x09, 0x0a, 0x0d, 0x0e, 0x03, 0x0c,
@@ -250,6 +250,88 @@ u32 get_cpr0_fbdv(unsigned long cpr_reg_fbdv)
 	return 0;
 }
 
+#if defined(CONFIG_APM82XXX)
+
+/*
+ * Specific for APM82XXX
+ * Change:
+ *	PLL registers reflect the current PLL setting of the chip.
+ *	So unlike previous implementation that reads bootstrap
+ *	registers to determine system clocking information, this
+ *	implementation directly extracts the information from
+ *	current PLL registers values.
+ */
+void get_sys_info(sys_info_t *sysInfo)
+{
+	unsigned long plld;
+	unsigned long temp;
+	unsigned long mul;
+	unsigned long cpudv;
+	unsigned long plb2dv;
+	unsigned long ddr2dv;
+
+	/* Calculate Forward divisor A and Feeback divisor */
+	mfcpr(CPR0_PLLD, plld);
+
+	temp = CPR0_PLLD_FWDVA(plld);
+	sysInfo->pllFwdDivA = get_cpr0_fwdv(temp);
+
+	temp = CPR0_PLLD_FDV(plld);
+	sysInfo->pllFbkDiv = get_cpr0_fbdv(temp);
+
+	/* Calculate OPB clock divisor */
+	mfcpr(CPR0_OPBD, temp);
+	temp = CPR0_OPBD_OPBDV(temp);
+	sysInfo->pllOpbDiv = temp ? temp : 4;
+
+	/* Calculate Peripheral clock divisor */
+	mfcpr(CPR0_PERD, temp);
+	temp = CPR0_PERD_PERDV(temp);
+	sysInfo->pllExtBusDiv = temp ? temp : 4;
+
+	/* Calculate CPU clock divisor */
+	mfcpr(CPR0_CPUD, temp);
+	temp = CPR0_CPUD_CPUDV(temp);
+	cpudv = temp ? temp : 8;
+
+	/* Calculate PLB2 clock divisor */
+	mfcpr(CPR0_PLB2D, temp);
+	temp = CPR0_PLB2D_PLB2DV(temp);
+	plb2dv = temp ? temp : 4;
+
+	/* Calculate DDR2 clock divisor */
+	mfcpr(CPR0_DDR2D, temp);
+	temp = CPR0_DDR2D_DDR2DV(temp);
+	ddr2dv = temp ? temp : 4;
+
+	/* Calculate 'M' based on feedback source */
+	mfcpr(CPR0_PLLC, temp);
+	temp = CPR0_PLLC_SEL(temp);
+	if (temp == 0) {
+		/* PLL internal feedback */
+		mul = sysInfo->pllFbkDiv;
+	} else {
+		/* PLL PerClk feedback */
+		mul = sysInfo->pllFwdDivA * sysInfo->pllFbkDiv * cpudv
+			* plb2dv * 2 * sysInfo->pllOpbDiv *
+			  sysInfo->pllExtBusDiv;
+	}
+
+	/* Now calculate the individual clocks */
+	sysInfo->freqVCOMhz = (mul * CONFIG_SYS_CLK_FREQ) + (mul >> 1);
+	sysInfo->freqProcessor = sysInfo->freqVCOMhz /
+		sysInfo->pllFwdDivA / cpudv;
+	sysInfo->freqPLB = sysInfo->freqVCOMhz /
+		sysInfo->pllFwdDivA / cpudv / plb2dv / 2;
+	sysInfo->freqOPB = sysInfo->freqPLB / sysInfo->pllOpbDiv;
+	sysInfo->freqEBC = sysInfo->freqOPB / sysInfo->pllExtBusDiv;
+	sysInfo->freqDDR = sysInfo->freqVCOMhz /
+		sysInfo->pllFwdDivA / cpudv / ddr2dv / 2;
+	sysInfo->freqUART = sysInfo->freqPLB;
+}
+
+#else
+
 /*
  * AMCC_TODO: verify this routine against latest EAS, cause stuff changed
  *            with latest EAS
@@ -307,6 +389,7 @@ void get_sys_info (sys_info_t * sysInfo)
 
 	return;
 }
+#endif
 
 #elif defined(CONFIG_440EP) || defined(CONFIG_440GR) || \
     defined(CONFIG_440EPX) || defined(CONFIG_440GRX)
-- 
1.6.1.rc3