On Thu, 17 Feb 2022 19:50:46 +0100 Pali Rohár <[email protected]> wrote:
> It is not possible for the A53 core (on which U-Boot is running) to read it > directly. For this purpose Marvell defined mbox API for sending OTP > commands between CM3 and A53 cores. > > Implement these Marvell fuse reading mbox commands via U-Boot fuse API. > > Banks 0-43 are used for accessing Security OTP (44 rows with 67 bits via 44 > banks and words 0-2). > > Note that of the 67 bits, the 3 upper bits are: 1 lock bit and 2 > auxiliary bits (meant for testing during the manufacture of the SOC, as > I understand it). > > Also note that the lock bit and the auxiliary bits are not readable > via Marvell commands. > > With CZ.NIC's commands the lock bit is readable. > > Write support is not implemented yet. > > Signed-off-by: Pali Rohár <[email protected]> > --- > arch/arm/mach-mvebu/armada3700/efuse.c | 38 ++++++++++++++++++++++++-- > 1 file changed, 36 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/mach-mvebu/armada3700/efuse.c > b/arch/arm/mach-mvebu/armada3700/efuse.c > index 03778f17ea49..fcf6edd08ce1 100644 > --- a/arch/arm/mach-mvebu/armada3700/efuse.c > +++ b/arch/arm/mach-mvebu/armada3700/efuse.c > @@ -8,6 +8,7 @@ > #include <common.h> > #include <asm/io.h> > #include <linux/delay.h> > +#include <mach/mbox.h> > #include <mach/soc.h> > > #define OTP_NB_REG_BASE ((void __iomem > *)MVEBU_REGISTER(0x12600)) > @@ -77,6 +78,40 @@ static void otp_read_parallel(void __iomem *base, u32 > *data, u32 count) > } > } > > +static int rwtm_otp_read(u8 row, u32 word, u32 *data) > +{ > + u32 out[3]; > + u32 in[2]; > + int res = -EINVAL; > + > + if (word < 2) { > + /* > + * MBOX_CMD_OTP_READ_32B command is supported by Marvell > + * fuse.bin firmware and also by new CZ.NIC wtmi firmware. > + * This command returns raw bits without ECC corrections. > + * It does not provide access to the lock bit. > + */ > + in[0] = row; > + in[1] = word * 32; > + res = mbox_do_cmd(MBOX_CMD_OTP_READ_32B, in, 2, out, 2); > + if (!res) > + *data = out[0]; > + } else if (word == 2) { > + /* > + * MBOX_CMD_OTP_READ command is supported only by CZ.NIC wtmi > + * firmware and provide nitpick: *provides Reviewed-by: Marek Behún <[email protected]>
