board/sifive/fu540/fu540.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2019 Western Digital Corporation or its affiliates.
   4  *
   5  * Authors:
   6  *   Anup Patel <anup.patel@wdc.com>
   7  */
   8
   9 #include <common.h>
  10 #include <dm.h>
  11 #include <env.h>
  12 #include <init.h>
  13 #include <linux/delay.h>
  14 #include <linux/io.h>
  15
  16 #ifdef CONFIG_MISC_INIT_R
  17
  18 #define FU540_OTP_BASE_ADDR                     0x10070000
  19
  20 struct fu540_otp_regs {
  21         u32 pa;     /* Address input */
  22         u32 paio;   /* Program address input */
  23         u32 pas;    /* Program redundancy cell selection input */
  24         u32 pce;    /* OTP Macro enable input */
  25         u32 pclk;   /* Clock input */
  26         u32 pdin;   /* Write data input */
  27         u32 pdout;  /* Read data output */
  28         u32 pdstb;  /* Deep standby mode enable input (active low) */
  29         u32 pprog;  /* Program mode enable input */
  30         u32 ptc;    /* Test column enable input */
  31         u32 ptm;    /* Test mode enable input */
  32         u32 ptm_rep;/* Repair function test mode enable input */
  33         u32 ptr;    /* Test row enable input */
  34         u32 ptrim;  /* Repair function enable input */
  35         u32 pwe;    /* Write enable input (defines program cycle) */
  36 } __packed;
  37
  38 #define BYTES_PER_FUSE                          4
  39 #define NUM_FUSES                               0x1000
  40
  41 static int fu540_otp_read(int offset, void *buf, int size)
  42 {
  43         struct fu540_otp_regs *regs = (void __iomem *)FU540_OTP_BASE_ADDR;
  44         unsigned int i;
  45         int fuseidx = offset / BYTES_PER_FUSE;
  46         int fusecount = size / BYTES_PER_FUSE;
  47         u32 fusebuf[fusecount];
  48
  49         /* check bounds */
  50         if (offset < 0 || size < 0)
  51                 return -EINVAL;
  52         if (fuseidx >= NUM_FUSES)
  53                 return -EINVAL;
  54         if ((fuseidx + fusecount) > NUM_FUSES)
  55                 return -EINVAL;
  56
  57         /* init OTP */
  58         writel(0x01, &regs->pdstb); /* wake up from stand-by */
  59         writel(0x01, &regs->ptrim); /* enable repair function */
  60         writel(0x01, &regs->pce);   /* enable input */
  61
  62         /* read all requested fuses */
  63         for (i = 0; i < fusecount; i++, fuseidx++) {
  64                 writel(fuseidx, &regs->pa);
  65
  66                 /* cycle clock to read */
  67                 writel(0x01, &regs->pclk);
  68                 mdelay(1);
  69                 writel(0x00, &regs->pclk);
  70                 mdelay(1);
  71
  72                 /* read the value */
  73                 fusebuf[i] = readl(&regs->pdout);
  74         }
  75
  76         /* shut down */
  77         writel(0, &regs->pce);
  78         writel(0, &regs->ptrim);
  79         writel(0, &regs->pdstb);
  80
  81         /* copy out */
  82         memcpy(buf, fusebuf, size);
  83
  84         return 0;
  85 }
  86
  87 static u32 fu540_read_serialnum(void)
  88 {
  89         int ret;
  90         u32 serial[2] = {0};
  91
  92         for (int i = 0xfe * 4; i > 0; i -= 8) {
  93                 ret = fu540_otp_read(i, serial, sizeof(serial));
  94                 if (ret) {
  95                         printf("%s: error reading from OTP\n", __func__);
  96                         break;
  97                 }
  98                 if (serial[0] == ~serial[1])
  99                         return serial[0];
 100         }
 101
 102         return 0;
 103 }
 104
 105 static void fu540_setup_macaddr(u32 serialnum)
 106 {
 107         /* Default MAC address */
 108         unsigned char mac[6] = { 0x70, 0xb3, 0xd5, 0x92, 0xf0, 0x00 };
 109
 110         /*
 111          * We derive our board MAC address by ORing last three bytes
 112          * of board serial number to above default MAC address.
 113          *
 114          * This logic of deriving board MAC address is taken from
 115          * SiFive FSBL and is kept unchanged.
 116          */
 117         mac[5] |= (serialnum >>  0) & 0xff;
 118         mac[4] |= (serialnum >>  8) & 0xff;
 119         mac[3] |= (serialnum >> 16) & 0xff;
 120
 121         /* Update environment variable */
 122         eth_env_set_enetaddr("ethaddr", mac);
 123 }
 124
 125 int misc_init_r(void)
 126 {
 127         u32 serial_num;
 128         char buf[9] = {0};
 129
 130         /* Set ethaddr environment variable from board serial number */
 131         if (!env_get("serial#")) {
 132                 serial_num = fu540_read_serialnum();
 133                 if (!serial_num) {
 134                         WARN(true, "Board serial number should not be 0 !!\n");
 135                         return 0;
 136                 }
 137                 snprintf(buf, sizeof(buf), "%08x", serial_num);
 138                 env_set("serial#", buf);
 139                 fu540_setup_macaddr(serial_num);
 140         }
 141         return 0;
 142 }
 143
 144 #endif
 145
 146 int board_init(void)
 147 {
 148         /* For now nothing to do here. */
 149
 150         return 0;
 151 }