[U-Boot] [PATCH 09/14] sunxi: dram: Add a helper function 'mctl_get_number_of_lanes'

Siarhei Siamashka siarhei.siamashka at gmail.com
Fri Jul 18 18:23:00 CEST 2014


It is going to be useful in more than one place.

Signed-off-by: Siarhei Siamashka <siarhei.siamashka at gmail.com>
---
 arch/arm/cpu/armv7/sunxi/dram.c | 30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/arch/arm/cpu/armv7/sunxi/dram.c b/arch/arm/cpu/armv7/sunxi/dram.c
index 18a5c3b..49d1770 100644
--- a/arch/arm/cpu/armv7/sunxi/dram.c
+++ b/arch/arm/cpu/armv7/sunxi/dram.c
@@ -115,23 +115,31 @@ static void mctl_enable_dll0(u32 phase)
 	udelay(22);
 }
 
+/* Get the number of DDR byte lanes */
+static u32 mctl_get_number_of_lanes(void)
+{
+	struct sunxi_dram_reg *dram = (struct sunxi_dram_reg *)SUNXI_DRAMC_BASE;
+	switch (readl(&dram->dcr) & DRAM_DCR_BUS_WIDTH_MASK) {
+	case DRAM_DCR_BUS_WIDTH(DRAM_DCR_BUS_WIDTH_32BIT):
+		return 4;
+	case DRAM_DCR_BUS_WIDTH(DRAM_DCR_BUS_WIDTH_16BIT):
+		return 2;
+	default:
+		return 1;
+	}
+}
+
 /*
  * Note: This differs from pm/standby in that it checks the bus width
  */
 static void mctl_enable_dllx(u32 phase)
 {
 	struct sunxi_dram_reg *dram = (struct sunxi_dram_reg *)SUNXI_DRAMC_BASE;
-	u32 i, n, bus_width;
-
-	bus_width = readl(&dram->dcr);
+	u32 i, number_of_lanes;
 
-	if ((bus_width & DRAM_DCR_BUS_WIDTH_MASK) ==
-	    DRAM_DCR_BUS_WIDTH(DRAM_DCR_BUS_WIDTH_32BIT))
-		n = DRAM_DCR_NR_DLLCR_32BIT;
-	else
-		n = DRAM_DCR_NR_DLLCR_16BIT;
+	number_of_lanes = mctl_get_number_of_lanes();
 
-	for (i = 1; i < n; i++) {
+	for (i = 1; i <= number_of_lanes; i++) {
 		clrsetbits_le32(&dram->dllcr[i], 0xf << 14,
 				(phase & 0xf) << 14);
 		clrsetbits_le32(&dram->dllcr[i], DRAM_DLLCR_NRESET,
@@ -140,12 +148,12 @@ static void mctl_enable_dllx(u32 phase)
 	}
 	udelay(2);
 
-	for (i = 1; i < n; i++)
+	for (i = 1; i <= number_of_lanes; i++)
 		clrbits_le32(&dram->dllcr[i], DRAM_DLLCR_NRESET |
 			     DRAM_DLLCR_DISABLE);
 	udelay(22);
 
-	for (i = 1; i < n; i++)
+	for (i = 1; i <= number_of_lanes; i++)
 		clrsetbits_le32(&dram->dllcr[i], DRAM_DLLCR_DISABLE,
 				DRAM_DLLCR_NRESET);
 	udelay(22);
-- 
1.8.3.2



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