coreboot-kgpe-d16/src/soc/sifive/fu540/otp.c
Elyes HAOUAS e30c396ffa src: Remove unused '#include <stddef.h>'
Unused includes found using following commande:
diff <(git grep -l '#include <stddef.h>' -- src/) <(git grep -l
'size_t\|ssize_t\|wchar_t\|wint_t\|NULL\|DEVTREE_EARLY\|DEVTREE_CONST\
|MAYBE_STATIC_NONZERO\|MAYBE_STATIC_BSS\|zeroptr' -- src/)|grep '<'
|grep -v vendor |grep -vF '.h'

Change-Id: Ic54b1db995fe7c61b416fa5e1c4022238e4a6ad5
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41150
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2020-05-13 08:48:50 +00:00

90 lines
2.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
#include <delay.h>
#include <device/mmio.h>
#include <console/console.h>
#include <console/uart.h>
#include <soc/addressmap.h>
#include <soc/otp.h>
/*
* This is a driver for the eMemory EG004K32TQ028XW01 NeoFuse
* One-Time-Programmable (OTP) memory used within the SiFive FU540.
* It is documented in the FU540 manual here:
* https://www.sifive.com/documentation/chips/freedom-u540-c000-manual/
*/
struct sifive_otp_registers {
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;
/*
* Read a 32 bit value addressed by its index from the OTP.
* The FU540 stores 4096x32 bit (16KiB) values.
* Index 0x00-0xff are reserved for SiFive internal use. (first 1KiB)
*/
u32 otp_read_word(u16 idx)
{
u32 w;
if (idx >= 0x1000)
die("otp: idx out of bounds");
struct sifive_otp_registers *regs = (void *)(FU540_OTP);
// wake up from stand-by
write32(&regs->pdstb, 0x01);
// enable repair function
write32(&regs->ptrim, 0x01);
// enable input
write32(&regs->pce, 0x01);
// address to read
write32(&regs->pa, idx);
// cycle clock to read
write32(&regs->pclk, 0x01);
mdelay(1);
write32(&regs->pclk, 0x00);
mdelay(1);
w = read32(&regs->pdout);
// shut down
write32(&regs->pce, 0x00);
write32(&regs->ptrim, 0x00);
write32(&regs->pdstb, 0x00);
return w;
}
u32 otp_read_serial(void)
{
u32 serial = 0;
u32 serial_n = 0;
for (int i = 0xfe; i > 0; i -= 2) {
serial = otp_read_word(i);
serial_n = otp_read_word(i+1);
if (serial == ~serial_n)
break;
}
return serial;
}