diff options
| -rw-r--r-- | arch/arm/cpu/armv7/sunxi/dram.c | 52 |
1 files changed, 47 insertions, 5 deletions
diff --git a/arch/arm/cpu/armv7/sunxi/dram.c b/arch/arm/cpu/armv7/sunxi/dram.c index 2ad685b..584f742 100644 --- a/arch/arm/cpu/armv7/sunxi/dram.c +++ b/arch/arm/cpu/armv7/sunxi/dram.c @@ -572,17 +572,13 @@ static void mctl_set_impedance(u32 zq, u32 odt_en) writel(DRAM_IOCR_ODT_EN(odt_en), &dram->iocr); } -unsigned long dramc_init(struct dram_para *para) +static unsigned long dramc_init_helper(struct dram_para *para) { struct sunxi_dram_reg *dram = (struct sunxi_dram_reg *)SUNXI_DRAMC_BASE; u32 reg_val; u32 density; int ret_val; - /* check input dram parameter structure */ - if (!para) - return 0; - /* * only single rank DDR3 is supported by this code even though the * hardware can theoretically support DDR2 and up to two ranks @@ -706,3 +702,49 @@ unsigned long dramc_init(struct dram_para *para) return get_ram_size((long *)PHYS_SDRAM_0, PHYS_SDRAM_0_SIZE); } + +unsigned long dramc_init(struct dram_para *para) +{ + unsigned long dram_size, actual_density; + + /* If the dram configuration is not provided, use a default */ + if (!para) + return 0; + + /* if everything is known, then autodetection is not necessary */ + if (para->io_width && para->bus_width && para->density) + return dramc_init_helper(para); + + /* try to autodetect the DRAM bus width and density */ + para->io_width = 16; + para->bus_width = 32; +#if defined(CONFIG_SUN4I) || defined(CONFIG_SUN5I) + /* only A0-A14 address lines on A10/A13, limiting max density to 4096 */ + para->density = 4096; +#else + /* all A0-A15 address lines on A20, which allow density 8192 */ + para->density = 8192; +#endif + + dram_size = dramc_init_helper(para); + if (!dram_size) { + /* if 32-bit bus width failed, try 16-bit bus width instead */ + para->bus_width = 16; + dram_size = dramc_init_helper(para); + if (!dram_size) { + /* if 16-bit bus width also failed, then bail out */ + return dram_size; + } + } + + /* check if we need to adjust the density */ + actual_density = (dram_size >> 17) * para->io_width / para->bus_width; + + if (actual_density != para->density) { + /* update the density and re-initialize DRAM again */ + para->density = actual_density; + dram_size = dramc_init_helper(para); + } + + return dram_size; +} |