early_reset.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <types.h>
#include <cf9_reset.h>
#include <device/pci_ops.h>
 
#include "gm45.h"
 
void gm45_early_reset(void/*const timings_t *const timings*/)
{
        int ch, r;
 
        /* Reset DRAM power-up settings in CLKCFG (they are not
           affected by system reset but may disrupt raminit). */
        mchbar_clrsetbits32(CLKCFG_MCHBAR, 3 << 21, 1 << 3);
 
        /*\ Next settings are the real purpose of this function:
            If these steps are not performed, reset results in power off. \*/
 
        /* Initialize some DRAM settings to 1 populated rank of 128MB. */
        FOR_EACH_CHANNEL(ch) {
                /* Configure DRAM control mode. */
                mchbar_clrsetbits32(CxDRC0_MCHBAR(ch), CxDRC0_RANKEN_MASK,
                        (ch ? 0 : CxDRC0_RANKEN(0)));
                mchbar_write32(CxDRC1_MCHBAR(ch),
                        (mchbar_read32(CxDRC1_MCHBAR(ch)) | CxDRC1_NOTPOP_MASK) &
                        ~(ch ? 0 : CxDRC1_NOTPOP(0)));
                mchbar_write32(CxDRC2_MCHBAR(ch),
                        (mchbar_read32(CxDRC2_MCHBAR(ch)) | CxDRC2_NOTPOP_MASK) &
                        ~(ch ? 0 : CxDRC2_NOTPOP(0)));
                /*if (timings && (timings->mem_clock == MEM_CLOCK_1067MT))
                        mchbar_setbits32(CxDRC2_MCHBAR(ch), CxDRC2_CLK1067MT);*/
 
                /* Program rank boundaries (CxDRBy). */
                for (r = 0; r < RANKS_PER_CHANNEL; r += 2)
                        mchbar_write32(CxDRBy_MCHBAR(ch, r),
                                CxDRBy_BOUND_MB(r, 128) | CxDRBy_BOUND_MB(r + 1, 128));
        }
        /* Set DCC mode to no operation and do magic 0xf0 thing. */
        mchbar_clrsetbits32(DCC_MCHBAR, DCC_CMD_MASK, DCC_CMD_NOP);
 
        pci_and_config8(PCI_DEV(0, 0, 0), 0xf0, ~(1 << 2));
 
        pci_or_config8(PCI_DEV(0, 0, 0), 0xf0, (1 << 2));
 
        /* Normally, we would set this after successful raminit. */
        mchbar_setbits32(DCC_MCHBAR, 1 << 19);
 
        system_reset();
}