diff options
Diffstat (limited to 'cpu/bf537/init_sdram.S')
| -rw-r--r-- | cpu/bf537/init_sdram.S | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/cpu/bf537/init_sdram.S b/cpu/bf537/init_sdram.S new file mode 100644 index 0000000..897a589 --- /dev/null +++ b/cpu/bf537/init_sdram.S @@ -0,0 +1,174 @@ +#define ASSEMBLY + +#include <linux/config.h> +#include <config.h> +#include <asm/blackfin.h> +#include <asm/mem_init.h> +.global init_sdram; + +#if (BFIN_BOOT_MODE != BF537_UART_BOOT) +#if (CONFIG_CCLK_DIV == 1) +#define CONFIG_CCLK_ACT_DIV CCLK_DIV1 +#endif +#if (CONFIG_CCLK_DIV == 2) +#define CONFIG_CCLK_ACT_DIV CCLK_DIV2 +#endif +#if (CONFIG_CCLK_DIV == 4) +#define CONFIG_CCLK_ACT_DIV CCLK_DIV4 +#endif +#if (CONFIG_CCLK_DIV == 8) +#define CONFIG_CCLK_ACT_DIV CCLK_DIV8 +#endif +#ifndef CONFIG_CCLK_ACT_DIV +#define CONFIG_CCLK_ACT_DIV CONFIG_CCLK_DIV_not_defined_properly +#endif +#endif + +init_sdram: + [--SP] = ASTAT; + [--SP] = RETS; + [--SP] = (R7:0); + [--SP] = (P5:0); + +#if (BFIN_BOOT_MODE == BF537_SPI_MASTER_BOOT) + p0.h = hi(SIC_IWR); + p0.l = lo(SIC_IWR); + r0.l = 0x1; + w[p0] = r0.l; + SSYNC; + + p0.h = hi(SPI_BAUD); + p0.l = lo(SPI_BAUD); + r0.l = CONFIG_SPI_BAUD; + w[p0] = r0.l; + SSYNC; +#endif + +#if (BFIN_BOOT_MODE != BF537_UART_BOOT) + +#ifdef CONFIG_BF537 + /* Enable PHY CLK buffer output */ + p0.h = hi(VR_CTL); + p0.l = lo(VR_CTL); + r0.l = w[p0]; + bitset(r0, 14); + w[p0] = r0.l; + ssync; +#endif + /* + * PLL_LOCKCNT - how many SCLK Cycles to delay while PLL becomes stable + */ + p0.h = hi(PLL_LOCKCNT); + p0.l = lo(PLL_LOCKCNT); + r0 = 0x300(Z); + w[p0] = r0.l; + ssync; + + /* + * Put SDRAM in self-refresh, incase anything is running + */ + P2.H = hi(EBIU_SDGCTL); + P2.L = lo(EBIU_SDGCTL); + R0 = [P2]; + BITSET (R0, 24); + [P2] = R0; + SSYNC; + + /* + * Set PLL_CTL with the value that we calculate in R0 + * - [14:09] = MSEL[5:0] : CLKIN / VCO multiplication factors + * - [8] = BYPASS : BYPASS the PLL, run CLKIN into CCLK/SCLK + * - [7] = output delay (add 200ps of delay to mem signals) + * - [6] = input delay (add 200ps of input delay to mem signals) + * - [5] = PDWN : 1=All Clocks off + * - [3] = STOPCK : 1=Core Clock off + * - [1] = PLL_OFF : 1=Disable Power to PLL + * - [0] = DF : 1=Pass CLKIN/2 to PLL / 0=Pass CLKIN to PLL + * all other bits set to zero + */ + + r0 = CONFIG_VCO_MULT & 63; /* Load the VCO multiplier */ + r0 = r0 << 9; /* Shift it over */ + r1 = CONFIG_CLKIN_HALF; /* Do we need to divide CLKIN by 2?*/ + r0 = r1 | r0; + r1 = CONFIG_PLL_BYPASS; /* Bypass the PLL? */ + r1 = r1 << 8; /* Shift it over */ + r0 = r1 | r0; /* add them all together */ + + p0.h = hi(PLL_CTL); + p0.l = lo(PLL_CTL); /* Load the address */ + cli r2; /* Disable interrupts */ + ssync; + w[p0] = r0.l; /* Set the value */ + idle; /* Wait for the PLL to stablize */ + sti r2; /* Enable interrupts */ + +check_again: + p0.h = hi(PLL_STAT); + p0.l = lo(PLL_STAT); + R0 = W[P0](Z); + CC = BITTST(R0,5); + if ! CC jump check_again; + + /* Configure SCLK & CCLK Dividers */ + r0 = (CONFIG_CCLK_ACT_DIV | CONFIG_SCLK_DIV); + p0.h = hi(PLL_DIV); + p0.l = lo(PLL_DIV); + w[p0] = r0.l; + ssync; +#endif + + /* + * Now, Initialize the SDRAM, + * start with the SDRAM Refresh Rate Control Register + */ + p0.l = lo(EBIU_SDRRC); + p0.h = hi(EBIU_SDRRC); + r0 = mem_SDRRC; + w[p0] = r0.l; + ssync; + + /* + * SDRAM Memory Bank Control Register - bank specific parameters + */ + p0.l = (EBIU_SDBCTL & 0xFFFF); + p0.h = (EBIU_SDBCTL >> 16); + r0 = mem_SDBCTL; + w[p0] = r0.l; + ssync; + + /* + * SDRAM Global Control Register - global programmable parameters + * Disable self-refresh + */ + P2.H = hi(EBIU_SDGCTL); + P2.L = lo(EBIU_SDGCTL); + R0 = [P2]; + BITCLR (R0, 24); + + /* + * Check if SDRAM is already powered up, if it is, enable self-refresh + */ + p0.h = hi(EBIU_SDSTAT); + p0.l = lo(EBIU_SDSTAT); + r2.l = w[p0]; + cc = bittst(r2,3); + if !cc jump skip; + NOP; + BITSET (R0, 23); +skip: + [P2] = R0; + SSYNC; + + /* Write in the new value in the register */ + R0.L = lo(mem_SDGCTL); + R0.H = hi(mem_SDGCTL); + [P2] = R0; + SSYNC; + nop; + + (P5:0) = [SP++]; + (R7:0) = [SP++]; + RETS = [SP++]; + ASTAT = [SP++]; + RTS; |