diff options
Diffstat (limited to 'arch/ppc/cpu/ppc4xx/40x_spd_sdram.c')
| -rw-r--r-- | arch/ppc/cpu/ppc4xx/40x_spd_sdram.c | 464 |
1 files changed, 464 insertions, 0 deletions
diff --git a/arch/ppc/cpu/ppc4xx/40x_spd_sdram.c b/arch/ppc/cpu/ppc4xx/40x_spd_sdram.c new file mode 100644 index 0000000..595d568 --- /dev/null +++ b/arch/ppc/cpu/ppc4xx/40x_spd_sdram.c @@ -0,0 +1,464 @@ +/* + * arch/ppc/cpu/ppc4xx/40x_spd_sdram.c + * This SPD SDRAM detection code supports IBM/AMCC PPC44x cpu with a + * SDRAM controller. Those are all current 405 PPC's. + * + * (C) Copyright 2001 + * Bill Hunter, Wave 7 Optics, williamhunter@attbi.com + * + * Based on code by: + * + * Kenneth Johansson ,Ericsson AB. + * kenneth.johansson@etx.ericsson.se + * + * hacked up by bill hunter. fixed so we could run before + * serial_init and console_init. previous version avoided this by + * running out of cache memory during serial/console init, then running + * this code later. + * + * (C) Copyright 2002 + * Jun Gu, Artesyn Technology, jung@artesyncp.com + * Support for AMCC 440 based on OpenBIOS draminit.c from IBM. + * + * (C) Copyright 2005 + * Stefan Roese, DENX Software Engineering, sr@denx.de. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <asm/processor.h> +#include <i2c.h> +#include <ppc4xx.h> + +#if defined(CONFIG_SPD_EEPROM) && !defined(CONFIG_440) + +/* + * Set default values + */ +#ifndef CONFIG_SYS_I2C_SPEED +#define CONFIG_SYS_I2C_SPEED 50000 +#endif + +#define ONE_BILLION 1000000000 + +#define SDRAM0_CFG_DCE 0x80000000 +#define SDRAM0_CFG_SRE 0x40000000 +#define SDRAM0_CFG_PME 0x20000000 +#define SDRAM0_CFG_MEMCHK 0x10000000 +#define SDRAM0_CFG_REGEN 0x08000000 +#define SDRAM0_CFG_ECCDD 0x00400000 +#define SDRAM0_CFG_EMDULR 0x00200000 +#define SDRAM0_CFG_DRW_SHIFT (31-6) +#define SDRAM0_CFG_BRPF_SHIFT (31-8) + +#define SDRAM0_TR_CASL_SHIFT (31-8) +#define SDRAM0_TR_PTA_SHIFT (31-13) +#define SDRAM0_TR_CTP_SHIFT (31-15) +#define SDRAM0_TR_LDF_SHIFT (31-17) +#define SDRAM0_TR_RFTA_SHIFT (31-29) +#define SDRAM0_TR_RCD_SHIFT (31-31) + +#define SDRAM0_RTR_SHIFT (31-15) +#define SDRAM0_ECCCFG_SHIFT (31-11) + +/* SDRAM0_CFG enable macro */ +#define SDRAM0_CFG_BRPF(x) ( ( x & 0x3)<< SDRAM0_CFG_BRPF_SHIFT ) + +#define SDRAM0_BXCR_SZ_MASK 0x000e0000 +#define SDRAM0_BXCR_AM_MASK 0x0000e000 + +#define SDRAM0_BXCR_SZ_SHIFT (31-14) +#define SDRAM0_BXCR_AM_SHIFT (31-18) + +#define SDRAM0_BXCR_SZ(x) ( (( x << SDRAM0_BXCR_SZ_SHIFT) & SDRAM0_BXCR_SZ_MASK) ) +#define SDRAM0_BXCR_AM(x) ( (( x << SDRAM0_BXCR_AM_SHIFT) & SDRAM0_BXCR_AM_MASK) ) + +#ifdef CONFIG_SPDDRAM_SILENT +# define SPD_ERR(x) do { return 0; } while (0) +#else +# define SPD_ERR(x) do { printf(x); return(0); } while (0) +#endif + +#define sdram_HZ_to_ns(hertz) (1000000000/(hertz)) + +/* function prototypes */ +int spd_read(uint addr); + + +/* + * This function is reading data from the DIMM module EEPROM over the SPD bus + * and uses that to program the sdram controller. + * + * This works on boards that has the same schematics that the AMCC walnut has. + * + * Input: null for default I2C spd functions or a pointer to a custom function + * returning spd_data. + */ + +long int spd_sdram(int(read_spd)(uint addr)) +{ + int tmp,row,col; + int total_size,bank_size,bank_code; + int ecc_on; + int mode; + int bank_cnt; + + int sdram0_pmit=0x07c00000; +#ifndef CONFIG_405EP /* not on PPC405EP */ + int sdram0_besr0 = -1; + int sdram0_besr1 = -1; + int sdram0_eccesr = -1; +#endif + int sdram0_ecccfg; + + int sdram0_rtr=0; + int sdram0_tr=0; + + int sdram0_b0cr; + int sdram0_b1cr; + int sdram0_b2cr; + int sdram0_b3cr; + + int sdram0_cfg=0; + + int t_rp; + int t_rcd; + int t_ras; + int t_rc; + int min_cas; + + PPC4xx_SYS_INFO sys_info; + unsigned long bus_period_x_10; + + /* + * get the board info + */ + get_sys_info(&sys_info); + bus_period_x_10 = ONE_BILLION / (sys_info.freqPLB / 10); + + if (read_spd == 0){ + read_spd=spd_read; + /* + * Make sure I2C controller is initialized + * before continuing. + */ + i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); + } + + /* Make shure we are using SDRAM */ + if (read_spd(2) != 0x04) { + SPD_ERR("SDRAM - non SDRAM memory module found\n"); + } + + /* ------------------------------------------------------------------ + * configure memory timing register + * + * data from DIMM: + * 27 IN Row Precharge Time ( t RP) + * 29 MIN RAS to CAS Delay ( t RCD) + * 127 Component and Clock Detail ,clk0-clk3, junction temp, CAS + * -------------------------------------------------------------------*/ + + /* + * first figure out which cas latency mode to use + * use the min supported mode + */ + + tmp = read_spd(127) & 0x6; + if (tmp == 0x02) { /* only cas = 2 supported */ + min_cas = 2; +/* t_ck = read_spd(9); */ +/* t_ac = read_spd(10); */ + } else if (tmp == 0x04) { /* only cas = 3 supported */ + min_cas = 3; +/* t_ck = read_spd(9); */ +/* t_ac = read_spd(10); */ + } else if (tmp == 0x06) { /* 2,3 supported, so use 2 */ + min_cas = 2; +/* t_ck = read_spd(23); */ +/* t_ac = read_spd(24); */ + } else { + SPD_ERR("SDRAM - unsupported CAS latency \n"); + } + + /* get some timing values, t_rp,t_rcd,t_ras,t_rc + */ + t_rp = read_spd(27); + t_rcd = read_spd(29); + t_ras = read_spd(30); + t_rc = t_ras + t_rp; + + /* The following timing calcs subtract 1 before deviding. + * this has effect of using ceiling instead of floor rounding, + * and also subtracting 1 to convert number to reg value + */ + /* set up CASL */ + sdram0_tr = (min_cas - 1) << SDRAM0_TR_CASL_SHIFT; + /* set up PTA */ + sdram0_tr |= ((((t_rp - 1) * 10)/bus_period_x_10) & 0x3) << SDRAM0_TR_PTA_SHIFT; + /* set up CTP */ + tmp = (((t_rc - t_rcd - t_rp -1) * 10) / bus_period_x_10) & 0x3; + if (tmp < 1) + tmp = 1; + sdram0_tr |= tmp << SDRAM0_TR_CTP_SHIFT; + /* set LDF = 2 cycles, reg value = 1 */ + sdram0_tr |= 1 << SDRAM0_TR_LDF_SHIFT; + /* set RFTA = t_rfc/bus_period, use t_rfc = t_rc */ + tmp = (((t_rc - 1) * 10) / bus_period_x_10) - 3; + if (tmp < 0) + tmp = 0; + if (tmp > 6) + tmp = 6; + sdram0_tr |= tmp << SDRAM0_TR_RFTA_SHIFT; + /* set RCD = t_rcd/bus_period*/ + sdram0_tr |= ((((t_rcd - 1) * 10) / bus_period_x_10) &0x3) << SDRAM0_TR_RCD_SHIFT ; + + + /*------------------------------------------------------------------ + * configure RTR register + * -------------------------------------------------------------------*/ + row = read_spd(3); + col = read_spd(4); + tmp = read_spd(12) & 0x7f ; /* refresh type less self refresh bit */ + switch (tmp) { + case 0x00: + tmp = 15625; + break; + case 0x01: + tmp = 15625 / 4; + break; + case 0x02: + tmp = 15625 / 2; + break; + case 0x03: + tmp = 15625 * 2; + break; + case 0x04: + tmp = 15625 * 4; + break; + case 0x05: + tmp = 15625 * 8; + break; + default: + SPD_ERR("SDRAM - Bad refresh period \n"); + } + /* convert from nsec to bus cycles */ + tmp = (tmp * 10) / bus_period_x_10; + sdram0_rtr = (tmp & 0x3ff8) << SDRAM0_RTR_SHIFT; + + /*------------------------------------------------------------------ + * determine the number of banks used + * -------------------------------------------------------------------*/ + /* byte 7:6 is module data width */ + if (read_spd(7) != 0) + SPD_ERR("SDRAM - unsupported module width\n"); + tmp = read_spd(6); + if (tmp < 32) + SPD_ERR("SDRAM - unsupported module width\n"); + else if (tmp < 64) + bank_cnt = 1; /* one bank per sdram side */ + else if (tmp < 73) + bank_cnt = 2; /* need two banks per side */ + else if (tmp < 161) + bank_cnt = 4; /* need four banks per side */ + else + SPD_ERR("SDRAM - unsupported module width\n"); + + /* byte 5 is the module row count (refered to as dimm "sides") */ + tmp = read_spd(5); + if (tmp == 1) + ; + else if (tmp==2) + bank_cnt *= 2; + else if (tmp==4) + bank_cnt *= 4; + else + bank_cnt = 8; /* 8 is an error code */ + + if (bank_cnt > 4) /* we only have 4 banks to work with */ + SPD_ERR("SDRAM - unsupported module rows for this width\n"); + + /* now check for ECC ability of module. We only support ECC + * on 32 bit wide devices with 8 bit ECC. + */ + if ((read_spd(11)==2) && (read_spd(6)==40) && (read_spd(14)==8)) { + sdram0_ecccfg = 0xf << SDRAM0_ECCCFG_SHIFT; + ecc_on = 1; + } else { + sdram0_ecccfg = 0; + ecc_on = 0; + } + + /*------------------------------------------------------------------ + * calculate total size + * -------------------------------------------------------------------*/ + /* calculate total size and do sanity check */ + tmp = read_spd(31); + total_size = 1 << 22; /* total_size = 4MB */ + /* now multiply 4M by the smallest device row density */ + /* note that we don't support asymetric rows */ + while (((tmp & 0x0001) == 0) && (tmp != 0)) { + total_size = total_size << 1; + tmp = tmp >> 1; + } + total_size *= read_spd(5); /* mult by module rows (dimm sides) */ + + /*------------------------------------------------------------------ + * map rows * cols * banks to a mode + * -------------------------------------------------------------------*/ + + switch (row) { + case 11: + switch (col) { + case 8: + mode=4; /* mode 5 */ + break; + case 9: + case 10: + mode=0; /* mode 1 */ + break; + default: + SPD_ERR("SDRAM - unsupported mode\n"); + } + break; + case 12: + switch (col) { + case 8: + mode=3; /* mode 4 */ + break; + case 9: + case 10: + mode=1; /* mode 2 */ + break; + default: + SPD_ERR("SDRAM - unsupported mode\n"); + } + break; + case 13: + switch (col) { + case 8: + mode=5; /* mode 6 */ + break; + case 9: + case 10: + if (read_spd(17) == 2) + mode = 6; /* mode 7 */ + else + mode = 2; /* mode 3 */ + break; + case 11: + mode = 2; /* mode 3 */ + break; + default: + SPD_ERR("SDRAM - unsupported mode\n"); + } + break; + default: + SPD_ERR("SDRAM - unsupported mode\n"); + } + + /*------------------------------------------------------------------ + * using the calculated values, compute the bank + * config register values. + * -------------------------------------------------------------------*/ + sdram0_b1cr = 0; + sdram0_b2cr = 0; + sdram0_b3cr = 0; + + /* compute the size of each bank */ + bank_size = total_size / bank_cnt; + /* convert bank size to bank size code for ppc4xx + by takeing log2(bank_size) - 22 */ + tmp = bank_size; /* start with tmp = bank_size */ + bank_code = 0; /* and bank_code = 0 */ + while (tmp > 1) { /* this takes log2 of tmp */ + bank_code++; /* and stores result in bank_code */ + tmp = tmp >> 1; + } /* bank_code is now log2(bank_size) */ + bank_code -= 22; /* subtract 22 to get the code */ + + tmp = SDRAM0_BXCR_SZ(bank_code) | SDRAM0_BXCR_AM(mode) | 1; + sdram0_b0cr = (bank_size * 0) | tmp; +#ifndef CONFIG_405EP /* not on PPC405EP */ + if (bank_cnt > 1) + sdram0_b2cr = (bank_size * 1) | tmp; + if (bank_cnt > 2) + sdram0_b1cr = (bank_size * 2) | tmp; + if (bank_cnt > 3) + sdram0_b3cr = (bank_size * 3) | tmp; +#else + /* PPC405EP chip only supports two SDRAM banks */ + if (bank_cnt > 1) + sdram0_b1cr = (bank_size * 1) | tmp; + if (bank_cnt > 2) + total_size = 2 * bank_size; +#endif + + /* + * enable sdram controller DCE=1 + * enable burst read prefetch to 32 bytes BRPF=2 + * leave other functions off + */ + + /*------------------------------------------------------------------ + * now that we've done our calculations, we are ready to + * program all the registers. + * -------------------------------------------------------------------*/ + + /* disable memcontroller so updates work */ + mtsdram(SDRAM0_CFG, 0); + +#ifndef CONFIG_405EP /* not on PPC405EP */ + mtsdram(SDRAM0_BESR0, sdram0_besr0); + mtsdram(SDRAM0_BESR1, sdram0_besr1); + mtsdram(SDRAM0_ECCCFG, sdram0_ecccfg); + mtsdram(SDRAM0_ECCESR, sdram0_eccesr); +#endif + mtsdram(SDRAM0_RTR, sdram0_rtr); + mtsdram(SDRAM0_PMIT, sdram0_pmit); + mtsdram(SDRAM0_B0CR, sdram0_b0cr); + mtsdram(SDRAM0_B1CR, sdram0_b1cr); +#ifndef CONFIG_405EP /* not on PPC405EP */ + mtsdram(SDRAM0_B2CR, sdram0_b2cr); + mtsdram(SDRAM0_B3CR, sdram0_b3cr); +#endif + mtsdram(SDRAM0_TR, sdram0_tr); + + /* SDRAM have a power on delay, 500 micro should do */ + udelay(500); + sdram0_cfg = SDRAM0_CFG_DCE | SDRAM0_CFG_BRPF(1) | SDRAM0_CFG_ECCDD | SDRAM0_CFG_EMDULR; + if (ecc_on) + sdram0_cfg |= SDRAM0_CFG_MEMCHK; + mtsdram(SDRAM0_CFG, sdram0_cfg); + + return (total_size); +} + +int spd_read(uint addr) +{ + uchar data[2]; + + if (i2c_read(SPD_EEPROM_ADDRESS, addr, 1, data, 1) == 0) + return (int)data[0]; + else + return 0; +} + +#endif /* CONFIG_SPD_EEPROM */ |