u-boot/arch/x86/cpu/broadwell/iobp.c
Simon Glass 1e6f4e5886 x86: broadwell: Add a PCH driver
Add a driver for the broadwell low-power platform controller hub.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Bin Meng <bmeng.cn@gmail.com>
2016-03-17 10:27:25 +08:00

144 lines
2.6 KiB
C

/*
* Copyright (c) 2016 Google, Inc
*
* Modified from coreboot
*
* SPDX-License-Identifier: GPL-2.0
*/
#include <common.h>
#include <errno.h>
#include <asm/intel_regs.h>
#include <asm/io.h>
#include <asm/arch/pch.h>
#define IOBP_RETRY 1000
/* IO Buffer Programming */
#define IOBPIRI 0x2330
#define IOBPD 0x2334
#define IOBPS 0x2338
#define IOBPS_READY 0x0001
#define IOBPS_TX_MASK 0x0006
#define IOBPS_MASK 0xff00
#define IOBPS_READ 0x0600
#define IOBPS_WRITE 0x0700
#define IOBPU 0x233a
#define IOBPU_MAGIC 0xf000
#define IOBP_PCICFG_READ 0x0400
#define IOBP_PCICFG_WRITE 0x0500
static inline int iobp_poll(void)
{
unsigned try;
for (try = IOBP_RETRY; try > 0; try--) {
u16 status = readw(RCB_REG(IOBPS));
if ((status & IOBPS_READY) == 0)
return 1;
udelay(10);
}
printf("IOBP: timeout waiting for transaction to complete\n");
return 0;
}
int pch_iobp_trans_start(u32 address, int op)
{
if (!iobp_poll())
return 0;
/* Set the address */
writel(address, RCB_REG(IOBPIRI));
/* READ OPCODE */
clrsetbits_le16(RCB_REG(IOBPS), IOBPS_MASK, op);
return 1;
}
int pch_iobp_trans_finish(void)
{
u16 status;
/* Undocumented magic */
writew(IOBPU_MAGIC, RCB_REG(IOBPU));
/* Set ready bit */
setbits_le16(RCB_REG(IOBPS), IOBPS_READY);
if (!iobp_poll())
return 1;
/* Check for successful transaction */
status = readw(RCB_REG(IOBPS));
if (status & IOBPS_TX_MASK)
return 1;
return 0;
}
u32 pch_iobp_read(u32 address)
{
if (!pch_iobp_trans_start(address, IOBPS_READ))
return 0;
if (pch_iobp_trans_finish()) {
printf("IOBP: read 0x%08x failed\n", address);
return 0;
}
/* Read IOBP data */
return readl(RCB_REG(IOBPD));
}
int pch_iobp_write(u32 address, u32 data)
{
if (!pch_iobp_trans_start(address, IOBPS_WRITE))
return -EIO;
writel(data, RCB_REG(IOBPD));
if (pch_iobp_trans_finish()) {
printf("IOBP: write 0x%08x failed\n", address);
return -EIO;
}
return 0;
}
int pch_iobp_update(u32 address, u32 andvalue, u32 orvalue)
{
u32 data = pch_iobp_read(address);
/* Update the data */
data &= andvalue;
data |= orvalue;
return pch_iobp_write(address, data);
}
int pch_iobp_exec(u32 addr, u16 op_code, u8 route_id, u32 *data, u8 *resp)
{
if (!data || !resp)
return 0;
*resp = -1;
if (!iobp_poll())
return -EIO;
writel(addr, RCB_REG(IOBPIRI));
clrsetbits_le16(RCB_REG(IOBPS), 0xff00, op_code);
writew(IOBPU_MAGIC | route_id, RCB_REG(IOBPU));
writel(*data, RCB_REG(IOBPD));
/* Set IOBPS[0] to trigger IOBP transaction*/
setbits_le16(RCB_REG(IOBPS), 1);
if (!iobp_poll())
return -EIO;
*resp = (readw(RCB_REG(IOBPS)) & IOBPS_TX_MASK) >> 1;
*data = readl(RCB_REG(IOBPD));
return 0;
}