[linux-sunxi] [PATCH 4/8] sunxi: add bank detection code to H3 DRAM initialization code

[Icenowy Zheng]

Some DDR2 DRAM have only four banks, not eight.

Add code to detect this situation.

Signed-off-by: Icenowy Zheng <icen...@aosc.xyz>
---
 arch/arm/mach-sunxi/dram_sunxi_dw.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/arch/arm/mach-sunxi/dram_sunxi_dw.c 
b/arch/arm/mach-sunxi/dram_sunxi_dw.c
index b08998c0d1..bb4457d2b8 100644
--- a/arch/arm/mach-sunxi/dram_sunxi_dw.c
+++ b/arch/arm/mach-sunxi/dram_sunxi_dw.c
@@ -31,6 +31,7 @@ struct dram_para {
        u8 bus_full_width;
        u8 dual_rank;
        u8 row_bits;
+       u8 bank_bits;
        const u8 dx_read_delays[NR_OF_BYTE_LANES][LINES_PER_BYTE_LANE];
        const u8 dx_write_delays[NR_OF_BYTE_LANES][LINES_PER_BYTE_LANE];
        const u8 ac_delays[31];
@@ -367,7 +368,7 @@ static void mctl_set_cr(struct dram_para *para)
                        (struct sunxi_mctl_com_reg *)SUNXI_DRAM_COM_BASE;
 
        writel(MCTL_CR_BL8 | MCTL_CR_2T | MCTL_CR_DDR3 | MCTL_CR_INTERLEAVED |
-              MCTL_CR_EIGHT_BANKS |
+              (para->bank_bits == 3 ? MCTL_CR_EIGHT_BANKS : 
MCTL_CR_FOUR_BANKS) |
               MCTL_CR_BUS_FULL_WIDTH(para->bus_full_width) |
               (para->dual_rank ? MCTL_CR_DUAL_RANK : MCTL_CR_SINGLE_RANK) |
               MCTL_CR_PAGE_SIZE(para->page_size) |
@@ -575,10 +576,19 @@ static void mctl_auto_detect_dram_size(struct dram_para 
*para)
        /* detect row address bits */
        para->page_size = 512;
        para->row_bits = 16;
+       para->bank_bits = 2;
        mctl_set_cr(para);
 
        for (para->row_bits = 11; para->row_bits < 16; para->row_bits++)
-               if (mctl_mem_matches((1 << (para->row_bits + 3)) * 
para->page_size))
+               if (mctl_mem_matches((1 << (para->row_bits + para->bank_bits)) 
* para->page_size))
+                       break;
+
+       /* detect bank address bits */
+       para->bank_bits = 3;
+       mctl_set_cr(para);
+
+       for (para->bank_bits = 2; para->bank_bits < 3; para->bank_bits++)
+               if (mctl_mem_matches((1 << para->bank_bits) * para->page_size))
                        break;
 
        /* detect page size */
@@ -640,6 +650,7 @@ unsigned long sunxi_dram_init(void)
                .dual_rank = 0,
                .bus_full_width = 1,
                .row_bits = 15,
+               .bank_bits = 3,
                .page_size = 4096,
 
 #if defined(CONFIG_MACH_SUN8I_H3)
@@ -689,6 +700,6 @@ unsigned long sunxi_dram_init(void)
        mctl_auto_detect_dram_size(&para);
        mctl_set_cr(&para);
 
-       return (1UL << (para.row_bits + 3)) * para.page_size *
-                                               (para.dual_rank ? 2 : 1);
+       return (1UL << (para.row_bits + para.bank_bits)) * para.page_size *
+              (para.dual_rank ? 2 : 1);
 }
-- 
2.12.0

-- 
You received this message because you are subscribed to the Google Groups 
"linux-sunxi" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to linux-sunxi+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.