[U-Boot] [PATCH v5 7/8] riscv: sifive: fu540: Setup ethaddr env variable using OTP

[Anup Patel]

This patch extends SiFive FU540 board support to setup ethaddr
env variable based on board serialnum read from OTP.

Signed-off-by: Anup Patel <anup.pa...@wdc.com>
---
 board/sifive/fu540/fu540.c     | 118 +++++++++++++++++++++++++++++++++
 configs/sifive_fu540_defconfig |   1 +
 2 files changed, 119 insertions(+)

diff --git a/board/sifive/fu540/fu540.c b/board/sifive/fu540/fu540.c
index 5adc4a3d4a..81f2025402 100644
--- a/board/sifive/fu540/fu540.c
+++ b/board/sifive/fu540/fu540.c
@@ -8,6 +8,124 @@
 
 #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 };
+
+       /* OR the serial into the MAC -- see SiFive FSBL */
+       mac[5] |= (serialnum >>  0) & 0xff;
+       mac[4] |= (serialnum >>  8) & 0xff;
+       mac[3] |= (serialnum >> 16) & 0xff;
+
+       /* Skip if environment variable already set */
+       if (env_get("ethaddr"))
+               return;
+
+       /* Update environment variable */
+       eth_env_set_enetaddr("ethaddr", mac);
+}
+
+int misc_init_r(void)
+{
+       fu540_setup_macaddr(fu540_read_serialnum());
+
+       return 0;
+}
+
+#endif
 
 int board_init(void)
 {
diff --git a/configs/sifive_fu540_defconfig b/configs/sifive_fu540_defconfig
index f78412398e..f19203745e 100644
--- a/configs/sifive_fu540_defconfig
+++ b/configs/sifive_fu540_defconfig
@@ -7,4 +7,5 @@ CONFIG_DISTRO_DEFAULTS=y
 CONFIG_FIT=y
 CONFIG_DISPLAY_CPUINFO=y
 CONFIG_DISPLAY_BOARDINFO=y
+CONFIG_MISC_INIT_R=y
 CONFIG_OF_PRIOR_STAGE=y
-- 
2.17.1

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