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device/dram: add DDR4 RCD I2C access functions

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Registering Clock Driver (RCD) is responsible for driving address and
control nets on RDIMM and LRDIMM applications. Its operation is
configurable by a set of Register Control Words (RCWs). There are two
ways of accessing RCWs: in-band on the memory channel as MRS commands
("MR7") or through I2C.

Access through I2C is generic, while MRS commands are passed to memory
controller registers in an implementation-specific way.

See JESD82-31 JEDEC standard for full details.

Change-Id: Ie4e6cfaeae16aba1853b33d527eddebadfbd3887
Signed-off-by: Krystian Hebel <krystian.hebel@3mdeb.com>
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/67060
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin L Roth <gaumless@gmail.com>
This commit is contained in:
Krystian Hebel 2021-03-25 15:05:27 +01:00 • committed by Felix Held
commit d3909e1793
3 changed files with 280 additions and 1 deletions
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61
src/include/device/dram/rcd.h Normal file
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/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef DEVICE_DRAM_RCD_H
#define DEVICE_DRAM_RCD_H
#include <types.h>
#include <device/i2c_simple.h>
#include <console/console.h>
enum rcw_idx {
VEN_ID_L,
VEN_ID_H,
DEV_ID_L,
DEV_ID_H,
REV_ID,
RES_05,
RES_06,
RES_07,
F0RC00_01,
F0RC02_03,
F0RC04_05,
F0RC06_07,
F0RC08_09,
F0RC0A_0B,
F0RC0C_0D,
F0RC0E_0F,
F0RC1x,
F0RC2x,
F0RC3x,
F0RC4x,
F0RC5x,
F0RC6x,
F0RC7x,
F0RC8x,
F0RC9x,
F0RCAx,
F0RCBx,
F0RCCx,
F0RCDx,
F0RCEx,
F0RCFx,
RCW_ALL, /* Total num of bytes */
RCW_ALL_ALIGNED /* Total num of bytes after aligning to 4B */
};
_Static_assert(RCW_ALL_ALIGNED % sizeof(uint32_t) == 0,
"RCW_ALL_ALIGNED is not aligned");
/* Write an 8-bit register. Returns the number of written bytes. */
int rcd_write_reg(unsigned int bus, uint8_t slave, enum rcw_idx reg,
uint8_t data);
/* Write 32 bits of memory (i.e., four 8-bit registers, not 1 32-bit register, which would
* involve byte swapping). Returns the number of written bytes. */
int rcd_write_32b(unsigned int bus, uint8_t slave, enum rcw_idx reg,
uint32_t data);
/* Dump 32 bytes of RCD onto the screen. */
void dump_rcd(unsigned int bus, uint8_t addr);
#endif /* DEVICE_DRAM_RCD_H */