[U-Boot] [PATCH v3 2/4] kirkwood: implement kw_sdram_bs_set()

[Holger Brunck]

From: Gerlando Falauto <gerlando.falauto at keymile.com>

Some boards might be equipped with different SDRAM configurations.
When that is the case, CPU CS Window Size Register (CS[0]n Size)
should be set to the biggest value through board.cfg file; then its
value can be fixed at runtime according to the detected SDRAM size.

Therefore, implement kw_sdram_bs_set().

Signed-off-by: Gerlando Falauto <gerlando.falauto at keymile.com>
Signed-off-by: Holger Brunck <holger.brunck at keymile.com>
cc: Prafulla Wadaskar <prafulla at marvell.com>
cc: Valentin Longchamp <valentin.longchamp at keymile.com>
cc: Marek Vasut <marex at denx.de>
---
changes for v3: 
  - remove reviewed by, because there are some chages in
  - use c-struct instead of defines
  - make kw_sdram_bs_set static
changes for v2:
  - added Reviewed-by: Marek Vasut <marex at denx.de>

 arch/arm/cpu/arm926ejs/kirkwood/dram.c |   24 ++++++++++++++++++++++++
 1 files changed, 24 insertions(+), 0 deletions(-)

diff --git a/arch/arm/cpu/arm926ejs/kirkwood/dram.c b/arch/arm/cpu/arm926ejs/kirkwood/dram.c
index 1c5faab..5e2f9d8 100644
--- a/arch/arm/cpu/arm926ejs/kirkwood/dram.c
+++ b/arch/arm/cpu/arm926ejs/kirkwood/dram.c
@@ -39,6 +39,11 @@ struct kw_sdram_addr_dec {
 	struct kw_sdram_bank	sdram_bank[4];
 };
 
+#define KW_REG_CPUCS_WIN_ENABLE		(1 << 0)
+#define KW_REG_CPUCS_WIN_WR_PROTECT	(1 << 1)
+#define KW_REG_CPUCS_WIN_WIN0_CS(x)	(((x) & 0x3) << 2)
+#define KW_REG_CPUCS_WIN_SIZE(x)	(((x) & 0xff) << 24)
+
 /*
  * kw_sdram_bar - reads SDRAM Base Address Register
  */
@@ -57,6 +62,25 @@ u32 kw_sdram_bar(enum memory_bank bank)
 }
 
 /*
+ * kw_sdram_bs_set - writes SDRAM Bank size
+ */
+static void kw_sdram_bs_set(enum memory_bank bank, u32 size)
+{
+	struct kw_sdram_addr_dec *base =
+		(struct kw_sdram_addr_dec *)KW_REGISTER(0x1500);
+	/* Read current register value */
+	u32 reg = readl(&base->sdram_bank[bank].win_sz);
+
+	/* Clear window size */
+	reg &= ~KW_REG_CPUCS_WIN_SIZE(0xFF);
+
+	/* Set new window size */
+	reg |= KW_REG_CPUCS_WIN_SIZE((size - 1) >> 24);
+
+	writel(reg, &base->sdram_bank[bank].win_sz);
+}
+
+/*
  * kw_sdram_bs - reads SDRAM Bank size
  */
 u32 kw_sdram_bs(enum memory_bank bank)
-- 
1.7.1