Add qemu 2.4.0
[kvmfornfv.git] / qemu / roms / u-boot / board / freescale / mpc7448hpc2 / asm_init.S
diff --git a/qemu/roms/u-boot/board/freescale/mpc7448hpc2/asm_init.S b/qemu/roms/u-boot/board/freescale/mpc7448hpc2/asm_init.S
new file mode 100644 (file)
index 0000000..70315c3
--- /dev/null
@@ -0,0 +1,905 @@
+/*
+ * (C) Copyright 2004-05;  Tundra Semiconductor Corp.
+ *
+ * Added automatic detect of SDC settings
+ * Copyright (c) 2005 Freescale Semiconductor, Inc.
+ * Maintainer tie-fei.zang@freescale.com
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+/*
+ * FILENAME: asm_init.s
+ *
+ * Originator: Alex Bounine
+ *
+ * DESCRIPTION:
+ * Initialization code for the Tundra Tsi108 bridge chip
+ *
+ */
+
+#include <config.h>
+#include <version.h>
+
+#include <ppc_asm.tmpl>
+#include <ppc_defs.h>
+#include <asm/processor.h>
+
+#include <tsi108.h>
+
+/*
+ * Build Configuration Options
+ */
+
+/* #define DISABLE_PBM         disables usage of PB Master */
+/* #define SDC_HARDCODED_INIT  config SDRAM controller with hardcoded values */
+/* #define SDC_AUTOPRECH_EN    enable SDRAM auto precharge */
+
+/*
+ * Hardcoded SDC settings
+ */
+
+#ifdef SDC_HARDCODED_INIT
+
+/* Micron MT9HTF6472AY-40EA1 : Unbuffered, 512MB, 400, CL3, Single Rank */
+
+#define VAL_SD_REFRESH (0x61A)
+#define VAL_SD_TIMING  (0x0308336b)
+#define VAL_SD_D0_CTRL (0x07100021)    /* auto-precharge disabled */
+#define VAL_SD_D0_BAR  (0x0FE00000)    /* 512MB @ 0x00000000 */
+#define VAL_SD_D1_CTRL (0x07100021)    /* auto-precharge disabled */
+#define VAL_SD_D1_BAR  (0x0FE00200)    /* 512MB @ 0x20000000 */
+
+#endif /* SDC_HARDCODED_INIT */
+
+/*
+ CPU Configuration:
+
+ CPU Address and Data Parity enables.
+
+#define CPU_AP
+#define CPU_DP
+*/
+
+/*
+ * Macros
+ * !!! Attention !!! Macros LOAD_PTR, LOAD_U32 and LOAD_MEM defined below are
+ * expected to work correctly for the CSR space within 32KB range.
+ *
+ * LOAD_PTR and LOAD_U32 - load specified register with a 32 bit constant.
+ * These macros are absolutely identical except their names. This difference
+ * is provided intentionally for better readable code.
+ */
+
+#define LOAD_PTR(reg,const32) \
+       addis reg,r0,const32@h; ori reg,reg,const32@l
+
+#define LOAD_U32(reg,const32) \
+       addis reg,r0,const32@h; ori reg,reg,const32@l
+
+/* LOADMEM initializes a register with the contents of a specified 32-bit
+ * memory location, usually a CSR value.
+ */
+
+#define LOAD_MEM(reg,addr32) \
+       addis reg,r0,addr32@ha; lwz reg,addr32@l(reg)
+
+#ifndef SDC_HARDCODED_INIT
+sdc_clk_sync:
+       /* MHz: 0,0,183,100,133,167,200,233 */
+       .long   0, 0, 6, 10, 8, 6, 5, 4         /* nSec */
+#endif
+
+/*
+ * board_asm_init() - early initialization function. Coded to be portable to
+ * dual-CPU configuration.
+ * Checks CPU number and performs board HW initialization if called for CPU0.
+ * Registers used: r3,r4,r5,r6,r19,r29
+ *
+ * NOTE: For dual-CPU configuration only CPU0 is allowed to configure Tsi108
+ * and the rest of the board. Current implementation demonstrates two
+ * possible ways to identify CPU number:
+ * - for MPC74xx platform: uses MSSCR0[ID] bit as defined in UM.
+ * - for PPC750FX/GX boards: uses WHO_AM_I bit reported by Tsi108.
+ */
+
+       .globl board_asm_init
+board_asm_init:
+       mflr    r19     /* Save LR to be able return later. */
+       bl      icache_enable   /* Enable icache to reduce reads from flash. */
+
+/* Initialize pointer to Tsi108 register space */
+
+       LOAD_PTR(r29,CONFIG_SYS_TSI108_CSR_RST_BASE)/* r29 - pointer to tsi108 CSR space */
+       ori r4,r29,TSI108_PB_REG_OFFSET
+
+/* Check Processor Version Number */
+
+       mfspr   r3, PVR
+       rlwinm  r3,r3,16,16,23  /* get ((Processor Version Number) & 0xFF00) */
+
+       cmpli   0,0,r3,0x8000   /* MPC74xx */
+       bne     cont_brd_init
+
+       /*
+        * For MPC744x/5x enable extended BATs[4-7]
+        * Sri: Set HIGH_BAT_EN and XBSEN, and SPD =1
+        * to disable prefetch
+        */
+
+       mfspr   r5, HID0
+       oris    r5, r5, 0x0080  /* Set HID0[HIGH_BAT_EN] bit #8 */
+       ori     r5, r5, 0x0380  /* Set SPD,XBSEN,SGE bits #22,23,24 */
+       mtspr   HID0, r5
+       isync
+       sync
+
+       /* Adding code to disable external interventions in MPX bus mode */
+       mfspr   r3, 1014
+       oris    r3, r3, 0x0100  /* Set the EIDIS bit in MSSCR0:  bit 7 */
+       mtspr   1014, r3
+       isync
+       sync
+
+       /* Sri: code to enable FP unit */
+       mfmsr   r3
+       ori     r3, r3, 0x2000
+       mtmsr   r3
+       isync
+       sync
+
+       /* def CONFIG_DUAL_CPU
+        * For MPC74xx processor, use MSSCR0[ID] bit to identify CPU number.
+        */
+#if(1)
+       mfspr   r3,1014         /* read MSSCR0 */
+       rlwinm. r3,r3,27,31,31  /* get processor ID number */
+       mtspr   SPRN_PIR,r3     /* Save CPU ID */
+       sync
+       bne     init_done
+       b       do_tsi108_init
+
+cont_brd_init:
+
+       /* An alternative method of checking the processor number (in addition
+        * to configuration using MSSCR0[ID] bit on MPC74xx).
+        * Good for IBM PPC750FX/GX.
+        */
+
+       lwz     r3,PB_BUS_MS_SELECT(r4) /* read PB_ID register */
+       rlwinm. r3,r3,24,31,31          /* get processor ID number */
+       bne init_done
+#else
+
+cont_brd_init:
+
+#endif /* CONFIG_DUAL_CPU */
+
+       /* Initialize Tsi108 chip */
+
+do_tsi108_init:
+
+       /*
+        * Adjust HLP/Flash parameters. By default after reset the HLP port is
+        * set to support slow devices. Better performance can be achived when
+        * an optimal parameters are used for specific EPROM device.
+        * NOTE: This should be performed ASAP for the emulation platform
+        * because it has 5MHz HLP clocking.
+        */
+
+#ifdef CONFIG_TSI108EMU
+       ori     r4,r29,TSI108_HLP_REG_OFFSET
+       LOAD_U32(r5,0x434422c0)
+       stw     r5,0x08(r4)     /* set HLP B0_CTRL0 */
+       sync
+       LOAD_U32(r5,0xd0012000)
+       stw     r5,0x0c(r4)             /* set HLP B0_CTRL1 */
+       sync
+#endif
+
+       /* Initialize PB interface. */
+
+       ori r4,r29,TSI108_PB_REG_OFFSET
+
+#if (CONFIG_SYS_TSI108_CSR_BASE != CONFIG_SYS_TSI108_CSR_RST_BASE)
+       /* Relocate (if required) Tsi108 registers. Set new value for
+        * PB_REG_BAR:
+        * Note we are in the 32-bit address mode.
+        */
+       LOAD_U32(r5,(CONFIG_SYS_TSI108_CSR_BASE | 0x01)) /* PB_REG_BAR: BA + EN */
+       stw     r5,PB_REG_BAR(r4)
+       andis.  r29,r5,0xFFFF
+       sync
+       ori     r4,r29,TSI108_PB_REG_OFFSET
+#endif
+
+       /* Set PB Slave configuration register */
+
+       LOAD_U32(r5,0x00002481) /* PB_SCR: TEA enabled,AACK delay = 1 */
+       lwz     r3, PB_RSR(r4)  /* get PB bus mode */
+       xori    r3,r3,0x0001    /* mask PB_BMODE: r3 -> (0 = 60X, 1 = MPX) */
+       rlwimi  r5,r3,14,17,17  /* for MPX: set DTI_MODE bit */
+       stw     r5,PB_SCR(r4)
+       sync
+
+       /* Configure PB Arbiter */
+
+       lwz     r5,PB_ARB_CTRL(r4)      /* Read PB Arbiter Control Register */
+       li      r3, 0x00F0              /* ARB_PIPELINE_DEP mask */
+#ifdef DISABLE_PBM
+       ori     r3,r3,0x1000    /* add PBM_EN to clear (enabled by default) */
+#endif
+       andc    r5,r5,r3        /* Clear the masked bit fields */
+       ori     r5,r5,0x0001    /* Set pipeline depth */
+       stw     r5,PB_ARB_CTRL(r4)
+
+#if (0)        /* currently using the default settings for PBM after reset */
+       LOAD_U32(r5,0x)         /* value for PB_MCR */
+       stw     r5,PB_MCR(r4)
+       sync
+
+       LOAD_U32(r5,0x)         /* value for PB_MCMD */
+       stw     r5,PB_MCMD(r4)
+       sync
+#endif
+
+       /* Disable or enable PVT based on processor bus frequency
+        * 1. Read CG_PWRUP_STATUS register field bits 18,17,16
+        * 2. See if the value is < or > 133mhz (18:16 = 100)
+        * 3. If > enable PVT
+        */
+
+       LOAD_U32(r3,0xC0002234)
+       lwz     r3,0(r3)
+       rlwinm  r3,r3,16,29,31
+
+       cmpi    0,0,r3,0x0004
+       bgt     sdc_init
+
+#ifndef CONFIG_TSI108EMU
+       /* FIXME: Disable PB calibration control for any real Tsi108 board */
+       li      r5,0x0101       /* disable calibration control */
+       stw     r5,PB_PVT_CTRL2(r4)
+       sync
+#endif
+
+       /* Initialize SDRAM controller. */
+
+sdc_init:
+
+#ifndef SDC_HARDCODED_INIT
+       /* get SDC clock prior doing sdram controller autoconfig */
+       ori     r4,r29,TSI108_CLK_REG_OFFSET    /* r4 - ptr to CG registers */
+       lwz     r3, CG_PWRUP_STATUS(r4)         /* get CG configuration */
+       rlwinm  r3,r3,12,29,31                  /* r3 - SD clk */
+       lis     r5,sdc_clk_sync@h
+       ori     r5,r5,sdc_clk_sync@l
+       /* Sri:  At this point check if r3 = 001. If yes,
+        * the memory frequency should be same as the
+        * MPX bus frequency
+        */
+       cmpi    0,0,r3,0x0001
+       bne     get_nsec
+       lwz     r6, CG_PWRUP_STATUS(r4)
+       rlwinm  r6,r6,16,29,31
+       mr      r3,r6
+
+get_nsec:
+       rlwinm  r3,r3,2,0,31
+       lwzx    r9,r5,r3        /* get SD clk rate in nSec */
+       /* ATTN: r9 will be used by SPD routine */
+#endif /* !SDC_HARDCODED_INIT */
+
+       ori     r4,r29,TSI108_SD_REG_OFFSET /* r4 - ptr to SDRAM registers */
+
+       /* Initialize SDRAM controller. SDRAM Size = 512MB, One DIMM. */
+
+       LOAD_U32(r5,0x00)
+       stw     r5,SD_INT_ENABLE(r4) /* Ensure that interrupts are disabled */
+#ifdef ENABLE_SDRAM_ECC
+       li      r5, 0x01
+#endif /* ENABLE_SDRAM_ECC */
+       stw     r5,SD_ECC_CTRL(r4)      /* Enable/Disable ECC */
+       sync
+
+#ifdef SDC_HARDCODED_INIT /* config sdram controller with hardcoded values */
+
+       /* First read the CG_PWRUP_STATUS register to get the
+        * memory speed from bits 22,21,20
+        */
+
+       LOAD_U32(r3,0xC0002234)
+       lwz     r3,0(r3)
+       rlwinm  r3,r3,12,29,31
+
+       /* Now first check for 166, then 200, or default */
+
+       cmpi    0,0,r3,0x0005
+       bne     check_for_200mhz
+
+       /* set values for 166 Mhz memory speed
+        * Set refresh rate and timing parameters
+        */
+       LOAD_U32(r5,0x00000515)
+       stw     r5,SD_REFRESH(r4)
+       LOAD_U32(r5,0x03073368)
+       stw     r5,SD_TIMING(r4)
+       sync
+
+       /* Initialize DIMM0 control and BAR registers */
+       LOAD_U32(r5,VAL_SD_D0_CTRL)     /* auto-precharge disabled */
+#ifdef SDC_AUTOPRECH_EN
+       oris    r5,r5,0x0001            /* set auto precharge EN bit */
+#endif
+       stw     r5,SD_D0_CTRL(r4)
+       LOAD_U32(r5,VAL_SD_D0_BAR)
+       stw     r5,SD_D0_BAR(r4)
+       sync
+
+       /* Initialize DIMM1 control and BAR registers
+        * (same as dimm 0, next 512MB, disabled)
+        */
+       LOAD_U32(r5,VAL_SD_D1_CTRL)     /* auto-precharge disabled */
+#ifdef SDC_AUTOPRECH_EN
+       oris    r5,r5,0x0001    /* set auto precharge EN bit */
+#endif
+       stw     r5,SD_D1_CTRL(r4)
+       LOAD_U32(r5,VAL_SD_D1_BAR)
+       stw     r5,SD_D1_BAR(r4)
+       sync
+
+       b       sdc_init_done
+
+check_for_200mhz:
+
+       cmpi    0,0,r3,0x0006
+       bne     set_default_values
+
+       /* set values for 200Mhz memory speed
+        * Set refresh rate and timing parameters
+        */
+       LOAD_U32(r5,0x0000061a)
+       stw     r5,SD_REFRESH(r4)
+       LOAD_U32(r5,0x03083348)
+       stw     r5,SD_TIMING(r4)
+       sync
+
+       /* Initialize DIMM0 control and BAR registers */
+       LOAD_U32(r5,VAL_SD_D0_CTRL)     /* auto-precharge disabled */
+#ifdef SDC_AUTOPRECH_EN
+       oris    r5,r5,0x0001            /* set auto precharge EN bit */
+#endif
+       stw     r5,SD_D0_CTRL(r4)
+       LOAD_U32(r5,VAL_SD_D0_BAR)
+       stw     r5,SD_D0_BAR(r4)
+       sync
+
+       /* Initialize DIMM1 control and BAR registers
+        * (same as dimm 0, next 512MB, disabled)
+        */
+       LOAD_U32(r5,VAL_SD_D1_CTRL)     /* auto-precharge disabled */
+#ifdef SDC_AUTOPRECH_EN
+       oris    r5,r5,0x0001            /* set auto precharge EN bit */
+#endif
+       stw     r5,SD_D1_CTRL(r4)
+       LOAD_U32(r5,VAL_SD_D1_BAR)
+       stw     r5,SD_D1_BAR(r4)
+       sync
+
+       b       sdc_init_done
+
+set_default_values:
+
+       /* Set refresh rate and timing parameters */
+       LOAD_U32(r5,VAL_SD_REFRESH)
+       stw     r5,SD_REFRESH(r4)
+       LOAD_U32(r5,VAL_SD_TIMING)
+       stw     r5,SD_TIMING(r4)
+       sync
+
+       /* Initialize DIMM0 control and BAR registers */
+       LOAD_U32(r5,VAL_SD_D0_CTRL)     /* auto-precharge disabled */
+#ifdef SDC_AUTOPRECH_EN
+       oris    r5,r5,0x0001            /* set auto precharge EN bit */
+#endif
+       stw     r5,SD_D0_CTRL(r4)
+       LOAD_U32(r5,VAL_SD_D0_BAR)
+       stw     r5,SD_D0_BAR(r4)
+       sync
+
+       /* Initialize DIMM1 control and BAR registers
+        * (same as dimm 0, next 512MB, disabled)
+        */
+       LOAD_U32(r5,VAL_SD_D1_CTRL)     /* auto-precharge disabled */
+#ifdef SDC_AUTOPRECH_EN
+       oris    r5,r5,0x0001            /* set auto precharge EN bit */
+#endif
+       stw     r5,SD_D1_CTRL(r4)
+       LOAD_U32(r5,VAL_SD_D1_BAR)
+       stw     r5,SD_D1_BAR(r4)
+       sync
+#else /* !SDC_HARDCODED_INIT */
+       bl      tsi108_sdram_spd        /* automatically detect SDC settings */
+#endif /* SDC_HARDCODED_INIT */
+
+sdc_init_done:
+
+#ifdef DISABLE_PBM
+       LOAD_U32(r5,0x00000030)         /* PB_EN + OCN_EN */
+#else
+       LOAD_U32(r5,0x00000230)         /* PB_EN + OCN_EN + PB/OCN=80/20 */
+#endif /* DISABLE_PBM */
+
+#ifdef CONFIG_TSI108EMU
+       oris    r5,r5,0x0010            /* set EMULATION_MODE bit */
+#endif
+
+       stw     r5,SD_CTRL(r4)
+       eieio
+       sync
+
+       /* Enable SDRAM access */
+
+       oris    r5,r5,0x8000            /* start SDC: set SD_CTRL[ENABLE] bit */
+       stw     r5,SD_CTRL(r4)
+       sync
+
+wait_init_complete:
+       lwz     r5,SD_STATUS(r4)
+       andi.   r5,r5,0x0001
+       /* wait until SDRAM initialization is complete */
+       beq     wait_init_complete
+
+       /* Map SDRAM into the processor bus address space */
+
+       ori     r4,r29,TSI108_PB_REG_OFFSET
+
+       /* Setup BARs associated with direct path PB<->SDRAM */
+
+       /* PB_SDRAM_BAR1:
+        * provides a direct path to the main system memory (cacheable SDRAM)
+        */
+
+       /* BA=0,Size=512MB, ENable, No Addr.Translation */
+       LOAD_U32(r5, 0x00000011)
+       stw     r5,PB_SDRAM_BAR1(r4)
+       sync
+
+       /* Make sure that PB_SDRAM_BAR1 decoder is set
+        * (to allow following immediate read from SDRAM)
+        */
+       lwz     r5,PB_SDRAM_BAR1(r4)
+       sync
+
+       /* PB_SDRAM_BAR2:
+        * provides non-cacheable alias (via the direct path) to main
+        * system memory.
+        * Size = 512MB, ENable, Addr.Translation - ON,
+        * BA = 0x0_40000000, TA = 0x0_00000000
+        */
+
+       LOAD_U32(r5, 0x40010011)
+       stw     r5,PB_SDRAM_BAR2(r4)
+       sync
+
+       /* Make sure that PB_SDRAM_BAR2 decoder is set
+        * (to allow following immediate read from SDRAM)
+        */
+       lwz     r5,PB_SDRAM_BAR2(r4)
+       sync
+
+init_done:
+
+       /* All done. Restore LR and return. */
+       mtlr    r19
+       blr
+
+#if (0)
+       /*
+        * init_cpu1
+        * This routine enables CPU1 on the dual-processor system.
+        * Now there is only one processor in the system
+        */
+
+       .global enable_cpu1
+enable_cpu1:
+
+       lis     r3,Tsi108_Base@ha       /* Get Grendel CSR Base Addr */
+       addi    r3,r3,Tsi108_Base@l
+       lwz     r3,0(r3)                /* R3 = CSR Base Addr */
+       ori     r4,r3,TSI108_PB_REG_OFFSET
+       lwz     r3,PB_ARB_CTRL(r4)      /* Read PB Arbiter Control Register */
+       ori     r3,r3,0x0200            /* Set M1_EN bit */
+       stw     r3,PB_ARB_CTRL(r4)
+
+       blr
+#endif
+
+       /*
+        * enable_EI
+        * Enable CPU core external interrupt
+        */
+
+       .global enable_EI
+enable_EI:
+       mfmsr   r3
+       ori     r3,r3,0x8000    /* set EE bit */
+       mtmsr   r3
+       blr
+
+       /*
+        * disable_EI
+        * Disable CPU core external interrupt
+        */
+
+       .global disable_EI
+disable_EI:
+       mfmsr   r3
+       li      r4,-32768       /* aka "li  r4,0x8000" */
+       andc    r3,r3,r4        /* clear EE bit */
+       mtmsr   r3
+       blr
+
+#ifdef ENABLE_SDRAM_ECC
+       /* enables SDRAM ECC  */
+
+       .global enable_ECC
+enable_ECC:
+       ori     r4,r29,TSI108_SD_REG_OFFSET
+       lwz     r3,SD_ECC_CTRL(r4)      /* Read SDRAM ECC Control Register */
+       ori     r3,r3,0x0001            /* Set ECC_EN bit */
+       stw     r3,SD_ECC_CTRL(r4)
+       blr
+
+       /*
+        * clear_ECC_err
+        * Clears all pending SDRAM ECC errors
+        * (normally after SDRAM scrubbing/initialization)
+        */
+
+       .global clear_ECC_err
+clear_ECC_err:
+       ori r4,r29,TSI108_SD_REG_OFFSET
+       ori r3,r0,0x0030        /* ECC_UE_INT + ECC_CE_INT bits */
+       stw r3,SD_INT_STATUS(r4)
+       blr
+
+#endif /* ENABLE_SDRAM_ECC */
+
+#ifndef SDC_HARDCODED_INIT
+
+       /* SDRAM SPD Support */
+#define        SD_I2C_CTRL1    (0x400)
+#define        SD_I2C_CTRL2    (0x404)
+#define SD_I2C_RD_DATA (0x408)
+#define SD_I2C_WR_DATA (0x40C)
+
+       /*
+        * SDRAM SPD Support Macros
+        */
+
+#define SPD_DIMM0      (0x00000100)
+#define SPD_DIMM1      (0x00000200)    /* SPD_DIMM1 was 0x00000000 */
+
+#define SPD_RDIMM                      (0x01)
+#define SPD_UDIMM                      (0x02)
+
+#define SPD_CAS_3                      0x8
+#define SPD_CAS_4                      0x10
+#define SPD_CAS_5                      0x20
+
+#define ERR_NO_DIMM_FOUND              (0xdb0)
+#define ERR_TRAS_FAIL                  (0xdb1)
+#define ERR_TRCD_FAIL                  (0xdb2)
+#define ERR_TRP_FAIL                   (0xdb3)
+#define ERR_TWR_FAIL                   (0xdb4)
+#define ERR_UNKNOWN_PART               (0xdb5)
+#define ERR_NRANK_INVALID              (0xdb6)
+#define ERR_DIMM_SIZE                  (0xdb7)
+#define ERR_ADDR_MODE                  (0xdb8)
+#define ERR_RFRSH_RATE                 (0xdb9)
+#define ERR_DIMM_TYPE                  (0xdba)
+#define ERR_CL_VALUE                   (0xdbb)
+#define ERR_TRFC_FAIL                  (0xdbc)
+
+/* READ_SPD requirements:
+ * byte - byte address in SPD device (0 - 255)
+ * r3 = will return data read from I2C Byte location
+ * r4 - unchanged (SDC base addr)
+ * r5 - clobbered in routine (I2C status)
+ * r10 - number of DDR slot where first SPD device is detected
+ */
+
+#define READ_SPD(byte_num)             \
+       addis   r3, 0, byte_num@l;      \
+       or      r3, r3, r10;            \
+       ori     r3, r3, 0x0A;           \
+       stw     r3, SD_I2C_CTRL1(r4);   \
+       li      r3, I2C_CNTRL2_START;   \
+       stw     r3, SD_I2C_CTRL2(r4);   \
+       eieio;                          \
+       sync;                           \
+       li      r3, 0x100;              \
+1:;                                    \
+       addic.  r3, r3, -1;             \
+       bne     1b;                     \
+2:;                                    \
+       lwz     r5, SD_I2C_CTRL2(r4);   \
+       rlwinm. r3,r5,0,23,23;          \
+       bne     2b;                     \
+       rlwinm. r3,r5,0,3,3;            \
+       lwz     r3,SD_I2C_RD_DATA(r4)
+
+#define SPD_MIN_RFRSH  (0x80)
+#define SPD_MAX_RFRSH  (0x85)
+
+refresh_rates: /* in nSec */
+       .long   15625   /* Normal (0x80) */
+       .long   3900    /* Reduced 0.25x (0x81) */
+       .long   7800    /* Reduced 0.5x (0x82) */
+       .long   31300   /* Extended 2x (0x83) */
+       .long   62500   /* Extended 4x (0x84) */
+       .long   125000  /* Extended 8x (0x85) */
+
+/*
+ * tsi108_sdram_spd
+ *
+ * Inittializes SDRAM Controller using DDR2 DIMM Serial Presence Detect data
+ * Uses registers: r4 - SDC base address (not changed)
+ *                                r9 - SDC clocking period in nSec
+ * Changes registers: r3,r5,r6,r7,r8,r10,r11
+ */
+
+tsi108_sdram_spd:
+
+       li      r10,SPD_DIMM0
+       xor     r11,r11,r11             /* DIMM Base Address: starts from 0 */
+
+do_first_dimm:
+
+       /* Program Refresh Rate Register */
+
+       READ_SPD(12)                    /* get Refresh Rate */
+       beq     check_next_slot
+       li      r5, ERR_RFRSH_RATE
+       cmpi    0,0,r3,SPD_MIN_RFRSH
+       ble     spd_fail
+       cmpi    0,0,r3,SPD_MAX_RFRSH
+       bgt     spd_fail
+       addi    r3,r3,-SPD_MIN_RFRSH
+       rlwinm  r3,r3,2,0,31
+       lis     r5,refresh_rates@h
+       ori     r5,r5,refresh_rates@l
+       lwzx    r5,r5,r3                /* get refresh rate in nSec */
+       divwu   r5,r5,r9                /* calculate # of SDC clocks */
+       stw     r5,SD_REFRESH(r4)       /* Set refresh rate */
+       sync
+
+       /* Program SD Timing Register */
+
+       li      r7, 0           /* clear r7 prior parameter collection */
+
+       READ_SPD(20)            /* get DIMM type: Registered or Unbuffered */
+       beq     spd_read_fail
+       li      r5, ERR_DIMM_TYPE
+       cmpi    0,0,r3,SPD_UDIMM
+       beq     do_cl
+       cmpi    0,0,r3,SPD_RDIMM
+       bne     spd_fail
+       oris    r7,r7,0x1000    /* set SD_TIMING[DIMM_TYPE] bit */
+
+do_cl:
+       READ_SPD(18)            /* Get CAS Latency */
+       beq     spd_read_fail
+       li      r5,ERR_CL_VALUE
+       andi.   r6,r3,SPD_CAS_3
+       beq     cl_4
+       li      r6,3
+       b       set_cl
+cl_4:
+       andi.   r6,r3,SPD_CAS_4
+       beq     cl_5
+       li      r6,4
+       b       set_cl
+cl_5:
+       andi.   r6,r3,SPD_CAS_5
+       beq     spd_fail
+       li      r6,5
+set_cl:
+       rlwimi  r7,r6,24,5,7
+
+       READ_SPD(30)            /* Get tRAS */
+       beq     spd_read_fail
+       divwu   r6,r3,r9
+       mullw   r8,r6,r9
+       subf.   r8,r8,r3
+       beq     set_tras
+       addi    r6,r6,1
+set_tras:
+       li r5,ERR_TRAS_FAIL
+       cmpi    0,0,r6,0x0F     /* max supported value */
+       bgt     spd_fail
+       rlwimi  r7,r6,16,12,15
+
+       READ_SPD(29)    /* Get tRCD */
+       beq     spd_read_fail
+       /* right shift tRCD by 2 bits as per DDR2 spec */
+       rlwinm  r3,r3,30,2,31
+       divwu   r6,r3,r9
+       mullw   r8,r6,r9
+       subf.   r8,r8,r3
+       beq     set_trcd
+       addi    r6,r6,1
+set_trcd:
+       li      r5,ERR_TRCD_FAIL
+       cmpi    0,0,r6,0x07     /* max supported value */
+       bgt     spd_fail
+       rlwimi  r7,r6,12,17,19
+
+       READ_SPD(27)    /* Get tRP value */
+       beq     spd_read_fail
+       rlwinm  r3,r3,30,2,31   /* right shift tRP by 2 bits as per DDR2 spec */
+       divwu   r6,r3,r9
+       mullw   r8,r6,r9
+       subf.   r8,r8,r3
+       beq     set_trp
+       addi    r6,r6,1
+set_trp:
+       li      r5,ERR_TRP_FAIL
+       cmpi    0,0,r6,0x07     /* max supported value */
+       bgt     spd_fail
+       rlwimi  r7,r6,8,21,23
+
+       READ_SPD(36)    /* Get tWR value */
+       beq     spd_read_fail
+       rlwinm  r3,r3,30,2,31   /* right shift tWR by 2 bits as per DDR2 spec */
+       divwu   r6,r3,r9
+       mullw   r8,r6,r9
+       subf.   r8,r8,r3
+       beq     set_twr
+       addi    r6,r6,1
+set_twr:
+       addi    r6,r6,-1        /* Tsi108 SDC always gives one extra clock */
+       li      r5,ERR_TWR_FAIL
+       cmpi    0,0,r6,0x07     /* max supported value */
+       bgt     spd_fail
+       rlwimi  r7,r6,5,24,26
+
+       READ_SPD(42)    /* Get tRFC */
+       beq     spd_read_fail
+       li      r5, ERR_TRFC_FAIL
+       /* Tsi108 spec: tRFC=(tRFC + 1)/2 */
+       addi    r3,r3,1
+       rlwinm. r3,r3,31,1,31   /* divide by 2 */
+       beq     spd_fail
+       divwu   r6,r3,r9
+       mullw   r8,r6,r9
+       subf.   r8,r8,r3
+       beq     set_trfc
+       addi    r6,r6,1
+set_trfc:
+       cmpi    0,0,r6,0x1F     /* max supported value */
+       bgt     spd_fail
+       rlwimi  r7,r6,0,27,31
+
+       stw     r7,SD_TIMING(r4)
+       sync
+
+       /*
+        * The following two registers are set on per-DIMM basis.
+        * The SD_REFRESH and SD_TIMING settings are common for both DIMMS
+        */
+
+do_each_dimm:
+
+       /* Program SDRAM DIMM Control Register */
+
+       li      r7, 0           /* clear r7 prior parameter collection */
+
+       READ_SPD(13)            /* Get Primary SDRAM Width */
+       beq     spd_read_fail
+       cmpi    0,0,r3,4        /* Check for 4-bit SDRAM */
+       beq     do_nbank
+       oris    r7,r7,0x0010    /* Set MEM_WIDTH bit */
+
+do_nbank:
+       READ_SPD(17)            /* Get Number of banks on SDRAM device */
+       beq     spd_read_fail
+       /* Grendel only distinguish betw. 4 or 8-bank memory parts */
+       li      r5,ERR_UNKNOWN_PART     /* non-supported memory part */
+       cmpi    0,0,r3,4
+       beq     do_nrank
+       cmpi    0,0,r3,8
+       bne     spd_fail
+       ori     r7,r7,0x1000
+
+do_nrank:
+       READ_SPD(5)             /* Get # of Ranks */
+       beq     spd_read_fail
+       li      r5,ERR_NRANK_INVALID
+       andi.   r6,r3,0x7       /* Use bits [2..0] only */
+       beq     do_addr_mode
+       cmpi    0,0,r6,1
+       bgt     spd_fail
+       rlwimi  r7,r6,8,23,23
+
+do_addr_mode:
+       READ_SPD(4)             /* Get # of Column Addresses */
+       beq     spd_read_fail
+       li      r5, ERR_ADDR_MODE
+       andi.   r3,r3,0x0f      /* cut off reserved bits */
+       cmpi    0,0,r3,8
+       ble     spd_fail
+       cmpi    0,0,r3,15
+       bgt     spd_fail
+       addi    r6,r3,-8        /* calculate ADDR_MODE parameter */
+       rlwimi  r7,r6,4,24,27   /* set ADDR_MODE field */
+
+set_dimm_ctrl:
+#ifdef SDC_AUTOPRECH_EN
+       oris    r7,r7,0x0001    /* set auto precharge EN bit */
+#endif
+       ori     r7,r7,1         /* set ENABLE bit */
+       cmpi    0,0,r10,SPD_DIMM0
+       bne     1f
+       stw     r7,SD_D0_CTRL(r4)
+       sync
+       b       set_dimm_bar
+1:
+       stw     r7,SD_D1_CTRL(r4)
+       sync
+
+
+       /* Program SDRAM DIMMx Base Address Register */
+
+set_dimm_bar:
+       READ_SPD(5)             /* get # of Ranks */
+       beq     spd_read_fail
+       andi.   r7,r3,0x7
+       addi    r7,r7,1
+       READ_SPD(31)            /* Read DIMM rank density */
+       beq     spd_read_fail
+       rlwinm  r5,r3,27,29,31
+       rlwinm  r6,r3,3,24,28
+       or      r5,r6,r5        /* r5 = Normalized Rank Density byte */
+       lis     r8, 0x0080      /* 128MB >> 4 */
+       mullw   r8,r8,r5        /* r8 = (rank_size >> 4) */
+       mullw   r8,r8,r7        /* r8 = (DIMM_size >> 4) */
+       neg     r7,r8
+       rlwinm  r7,r7,28,4,31
+       or      r7,r7,r11       /* set ADDR field */
+       rlwinm  r8,r8,12,20,31
+       add     r11,r11,r8      /* set Base Addr for next DIMM */
+
+       cmpi    0,0,r10,SPD_DIMM0
+       bne     set_dimm1_size
+       stw     r7,SD_D0_BAR(r4)
+       sync
+       li      r10,SPD_DIMM1
+       READ_SPD(0)
+       bne do_each_dimm
+       b spd_done
+
+set_dimm1_size:
+       stw     r7,SD_D1_BAR(r4)
+       sync
+spd_done:
+       blr
+
+check_next_slot:
+       cmpi    0,0,r10,SPD_DIMM1
+       beq     spd_read_fail
+       li      r10,SPD_DIMM1
+       b       do_first_dimm
+spd_read_fail:
+       ori     r3,r0,0xdead
+       b       err_hung
+spd_fail:
+       li      r3,0x0bad
+       sync
+err_hung:      /* hang here for debugging */
+       nop
+       nop
+       b       err_hung
+
+#endif /* !SDC_HARDCODED_INIT */