[U-Boot] [PATCH v7 7/9] riscv: sifive: fu540: Setup ethaddr env variable using OTP

[Troy Benjegerdes]

> On Jun 23, 2019, at 11:03 PM, Anup Patel <Anup.Patel at wdc.com> wrote:
> 
> 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.patel at wdc.com>
> ---
> board/sifive/fu540/fu540.c     | 122 +++++++++++++++++++++++++++++++++
> configs/sifive_fu540_defconfig |   1 +
> 2 files changed, 123 insertions(+)
> 
> diff --git a/board/sifive/fu540/fu540.c b/board/sifive/fu540/fu540.c
> index 5adc4a3d4a..11daf1a75a 100644
> --- a/board/sifive/fu540/fu540.c
> +++ b/board/sifive/fu540/fu540.c
> @@ -8,6 +8,128 @@
> 
> #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;
> +}

Please take a look at the DM-enabled SiFive OTP driver submitted by Joey Hewitt at
https://github.com/sifive/HiFive_U-Boot/commit/6d842765de142b61f847852da7a9ce0d081d770c

This Joey's version also sets the ‘serial#’ environment variable, while this patch only sets ‘ethaddr'

> +
> +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)
> {
> 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
>