iobp.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <console/console.h>
#include <delay.h>
#include "pch.h"
#include "iobp.h"
 
#define IOBP_RETRY 1000
 
static inline int iobp_poll(void)
{
        unsigned int try;
 
        for (try = IOBP_RETRY; try > 0; try--) {
                u16 status = RCBA16(IOBPS);
                if ((status & IOBPS_READY) == 0)
                        return 1;
                udelay(10);
        }
 
        printk(BIOS_ERR, "IOBP: timeout waiting for transaction to complete\n");
        return 0;
}
 
u32 pch_iobp_read(u32 address)
{
        u16 status;
 
        if (!iobp_poll())
                return 0;
 
        /* Set the address */
        RCBA32(IOBPIRI) = address;
 
        /* READ OPCODE */
        status = RCBA16(IOBPS);
        status &= ~IOBPS_MASK;
        status |= IOBPS_READ;
        RCBA16(IOBPS) = status;
 
        /* Undocumented magic */
        RCBA16(IOBPU) = IOBPU_MAGIC;
 
        /* Set ready bit */
        status = RCBA16(IOBPS);
        status |= IOBPS_READY;
        RCBA16(IOBPS) = status;
 
        if (!iobp_poll())
                return 0;
 
        /* Check for successful transaction */
        status = RCBA16(IOBPS);
        if (status & IOBPS_TX_MASK) {
                printk(BIOS_ERR, "IOBP: read 0x%08x failed\n", address);
                return 0;
        }
 
        /* Read IOBP data */
        return RCBA32(IOBPD);
}
 
void pch_iobp_write(u32 address, u32 data)
{
        u16 status;
 
        if (!iobp_poll())
                return;
 
        /* Set the address */
        RCBA32(IOBPIRI) = address;
 
        /* WRITE OPCODE */
        status = RCBA16(IOBPS);
        status &= ~IOBPS_MASK;
        status |= IOBPS_WRITE;
        RCBA16(IOBPS) = status;
 
        RCBA32(IOBPD) = data;
 
        /* Undocumented magic */
        RCBA16(IOBPU) = IOBPU_MAGIC;
 
        /* Set ready bit */
        status = RCBA16(IOBPS);
        status |= IOBPS_READY;
        RCBA16(IOBPS) = status;
 
        if (!iobp_poll())
                return;
 
        /* Check for successful transaction */
        status = RCBA16(IOBPS);
        if (status & IOBPS_TX_MASK) {
                printk(BIOS_ERR, "IOBP: write 0x%08x failed\n", address);
                return;
        }
 
        printk(BIOS_SPEW, "IOBP: set 0x%08x to 0x%08x\n", address, data);
}
 
void pch_iobp_update(u32 address, u32 andvalue, u32 orvalue)
{
        u32 data = pch_iobp_read(address);
 
        /* Update the data */
        data &= andvalue;
        data |= orvalue;
 
        pch_iobp_write(address, data);
}
 
void pch_iobp_exec(u32 addr, u16 op_code, u8 route_id, u32 *data, u8 *resp)
{
        if (!data || !resp)
                return;
 
        *resp = -1;
        if (!iobp_poll())
                return;
 
        /* RCBA2330[31:0] = Address */
        RCBA32(IOBPIRI) = addr;
        /* RCBA2338[15:8] = opcode */
        RCBA16(IOBPS) = (RCBA16(IOBPS) & 0x00ff) | op_code;
        /* RCBA233A[15:8] = 0xf0 RCBA233A[7:0] = Route ID */
        RCBA16(IOBPU) = IOBPU_MAGIC | route_id;
 
        if (op_code == IOBP_PCICFG_WRITE)
                RCBA32(IOBPD) = *data;
        /* Set RCBA2338[0] to trigger IOBP transaction*/
        RCBA16(IOBPS) = RCBA16(IOBPS) | 0x1;
 
        if (!iobp_poll())
                return;
 
        *resp = (RCBA16(IOBPS) & IOBPS_TX_MASK) >> 1;
        *data = RCBA32(IOBPD);
}