u-boot/board/sifive/fu540/fu540.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2019 Western Digital Corporation or its affiliates.
*
* Authors:
* Anup Patel <anup.patel@wdc.com>
*/
#include <common.h>
#include <dm.h>
#include <linux/delay.h>
#include <linux/io.h>
#ifdef CONFIG_MISC_INIT_R
#define FU540_OTP_BASE_ADDR 0x10070000
struct fu540_otp_regs {
u32 pa; /* Address input */
u32 paio; /* Program address input */
u32 pas; /* Program redundancy cell selection input */
u32 pce; /* OTP Macro enable input */
u32 pclk; /* Clock input */
u32 pdin; /* Write data input */
u32 pdout; /* Read data output */
u32 pdstb; /* Deep standby mode enable input (active low) */
u32 pprog; /* Program mode enable input */
u32 ptc; /* Test column enable input */
u32 ptm; /* Test mode enable input */
u32 ptm_rep;/* Repair function test mode enable input */
u32 ptr; /* Test row enable input */
u32 ptrim; /* Repair function enable input */
u32 pwe; /* Write enable input (defines program cycle) */
} __packed;
#define BYTES_PER_FUSE 4
#define NUM_FUSES 0x1000
static int fu540_otp_read(int offset, void *buf, int size)
{
struct fu540_otp_regs *regs = (void __iomem *)FU540_OTP_BASE_ADDR;
unsigned int i;
int fuseidx = offset / BYTES_PER_FUSE;
int fusecount = size / BYTES_PER_FUSE;
u32 fusebuf[fusecount];
/* check bounds */
if (offset < 0 || size < 0)
return -EINVAL;
if (fuseidx >= NUM_FUSES)
return -EINVAL;
if ((fuseidx + fusecount) > NUM_FUSES)
return -EINVAL;
/* init OTP */
writel(0x01, &regs->pdstb); /* wake up from stand-by */
writel(0x01, &regs->ptrim); /* enable repair function */
writel(0x01, &regs->pce); /* enable input */
/* read all requested fuses */
for (i = 0; i < fusecount; i++, fuseidx++) {
writel(fuseidx, &regs->pa);
/* cycle clock to read */
writel(0x01, &regs->pclk);
mdelay(1);
writel(0x00, &regs->pclk);
mdelay(1);
/* read the value */
fusebuf[i] = readl(&regs->pdout);
}
/* shut down */
writel(0, &regs->pce);
writel(0, &regs->ptrim);
writel(0, &regs->pdstb);
/* copy out */
memcpy(buf, fusebuf, size);
return 0;
}
static u32 fu540_read_serialnum(void)
{
int ret;
u32 serial[2] = {0};
for (int i = 0xfe * 4; i > 0; i -= 8) {
ret = fu540_otp_read(i, serial, sizeof(serial));
if (ret) {
printf("%s: error reading from OTP\n", __func__);
break;
}
if (serial[0] == ~serial[1])
return serial[0];
}
return 0;
}
static void fu540_setup_macaddr(u32 serialnum)
{
/* Default MAC address */
unsigned char mac[6] = { 0x70, 0xb3, 0xd5, 0x92, 0xf0, 0x00 };
/*
* We derive our board MAC address by ORing last three bytes
* of board serial number to above default MAC address.
*
* This logic of deriving board MAC address is taken from
* SiFive FSBL and is kept unchanged.
*/
mac[5] |= (serialnum >> 0) & 0xff;
mac[4] |= (serialnum >> 8) & 0xff;
mac[3] |= (serialnum >> 16) & 0xff;
/* Update environment variable */
eth_env_set_enetaddr("ethaddr", mac);
}
int misc_init_r(void)
{
/* Set ethaddr environment variable if not set */
if (!env_get("ethaddr"))
fu540_setup_macaddr(fu540_read_serialnum());
return 0;
}
#endif
int board_init(void)
{
/* For now nothing to do here. */
return 0;
}