[U-Boot] [PATCH v5 7/8] riscv: sifive: fu540: Setup ethaddr env variable using OTP
Anup Patel
anup at brainfault.org
Fri Jun 21 12:49:28 UTC 2019
On Fri, Jun 21, 2019 at 12:48 PM Bin Meng <bmeng.cn at gmail.com> wrote:
>
> Hi Anup,
>
> On Thu, Jun 20, 2019 at 2:49 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 | 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, ®s->pdstb); /* wake up from stand-by */
> > + writel(0x01, ®s->ptrim); /* enable repair function */
> > + writel(0x01, ®s->pce); /* enable input */
> > +
> > + /* read all requested fuses */
> > + for (i = 0; i < fusecount; i++, fuseidx++) {
> > + writel(fuseidx, ®s->pa);
> > +
> > + /* cycle clock to read */
> > + writel(0x01, ®s->pclk);
> > + mdelay(1);
> > + writel(0x00, ®s->pclk);
> > + mdelay(1);
> > +
> > + /* read the value */
> > + fusebuf[i] = readl(®s->pdout);
> > + }
> > +
> > + /* shut down */
> > + writel(0, ®s->pce);
> > + writel(0, ®s->ptrim);
> > + writel(0, ®s->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 };
>
> Why are the last 3 bytes of the default MAC address not zero? My
> understanding is that the first 3 numbers indicate the vendor and
> vendor is free to use the last 3 bytes for different devices.
Your understanding about MAC address is correct.
I don't know why last three bytes are ORed and not assigned. The
logic is taken from FSBL.
I did not want users to see different MAC address after this patch
so I have kept the logic same.
>
> > +
> > + /* 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;
>
> I think we should make the function clear by:
> * ether move this logic to out of this function, and do such check in
> misc_init_r()
>
> OR
> * unconditionally overwrite the "ethaddr" by removing this check
>
> I am OK with either way.
Sure, I will move the env_get() check to misc_init_r().
>
> > +
> > + /* Update environment variable */
> > + eth_env_set_enetaddr("ethaddr", mac);
> > +}
> > +
> > +int misc_init_r(void)
> > +{
> > + fu540_setup_macaddr(fu540_read_serialnum());
> > +
> > + return 0;
> > +}
> > +
> > +#endif
> >
>
> Regards,
> Bin
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Regards,
Anup
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