rk3288: sdram: auto-detect the capacity

Add support for rk3288 dram capacity auto detect, support DDR3 and
LPDDR3, DDR2 is not supported.
The program will automatically detect:
- channel number
- rank number
- column address number
- row address number

The dts file do not need to describe those info after apply this patch.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Tested-by: Simon Glass <sjg@chromium.org>
Tested-by: Vagrant Cascadian <vagrant@debian.org>
Tested-by: Vagrant Cascadian <vagrant@debian.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/arch/arm/include/asm/arch-rockchip/sdram.h b/arch/arm/include/asm/arch-rockchip/sdram.h
index 82c3d07..d7d67ba 100644
--- a/arch/arm/include/asm/arch-rockchip/sdram.h
+++ b/arch/arm/include/asm/arch-rockchip/sdram.h
@@ -16,6 +16,11 @@ enum {
 };
 
 struct rk3288_sdram_channel {
+	/*
+	 * bit width in address, eg:
+	 * 8 banks using 3 bit to address,
+	 * 2 cs using 1 bit to address.
+	 */
 	u8 rank;
 	u8 col;
 	u8 bk;
@@ -87,6 +92,16 @@ struct rk3288_base_params {
 	u32 ddrconfig;
 	u32 ddr_freq;
 	u32 dramtype;
+	/*
+	 * DDR Stride is address mapping for DRAM space
+	 * Stride	Ch 0 range	Ch1 range	Total
+	 * 0x00		0-256MB		256MB-512MB	512MB
+	 * 0x05		0-1GB		0-1GB		1GB
+	 * 0x09		0-2GB		0-2GB		2GB
+	 * 0x0d		0-4GB		0-4GB		4GB
+	 * 0x17		N/A		0-4GB		4GB
+	 * 0x1a		0-4GB		4GB-8GB		8GB
+	 */
 	u32 stride;
 	u32 odt;
 };