u-boot/arch/mips/mach-mtmips/ddr_calibrate.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2018 Stefan Roese <sr@denx.de>
*
* This code is mostly based on the code extracted from this MediaTek
* github repository:
*
* https://github.com/MediaTek-Labs/linkit-smart-uboot.git
*
* I was not able to find a specific license or other developers
* copyrights here, so I can't add them here.
*
* Most functions in this file are copied from the MediaTek U-Boot
* repository. Without any documentation, it was impossible to really
* implement this differently. So its mostly a cleaned-up version of
* the original code, with only support for the MT7628 / MT7688 SoC.
*/
#include <common.h>
#include <cpu_func.h>
#include <linux/io.h>
#include <asm/cacheops.h>
#include <asm/io.h>
#include "mt76xx.h"
#define NUM_OF_CACHELINE 128
#define MIN_START 6
#define MIN_FINE_START 0xf
#define MAX_START 7
#define MAX_FINE_START 0x0
#define CPU_FRAC_DIV 1
#if defined(CONFIG_ONBOARD_DDR2_SIZE_256MBIT)
#define DRAM_BUTTOM 0x02000000
#endif
#if defined(CONFIG_ONBOARD_DDR2_SIZE_512MBIT)
#define DRAM_BUTTOM 0x04000000
#endif
#if defined(CONFIG_ONBOARD_DDR2_SIZE_1024MBIT)
#define DRAM_BUTTOM 0x08000000
#endif
#if defined(CONFIG_ONBOARD_DDR2_SIZE_2048MBIT)
#define DRAM_BUTTOM 0x10000000
#endif
static inline void cal_memcpy(void *src, void *dst, u32 size)
{
u8 *psrc = (u8 *)src;
u8 *pdst = (u8 *)dst;
int i;
for (i = 0; i < size; i++, psrc++, pdst++)
*pdst = *psrc;
}
static inline void cal_memset(void *src, u8 pat, u32 size)
{
u8 *psrc = (u8 *)src;
int i;
for (i = 0; i < size; i++, psrc++)
*psrc = pat;
}
#define pref_op(hint, addr) \
__asm__ __volatile__( \
".set push\n" \
".set noreorder\n" \
"pref %0, %1\n" \
".set pop\n" \
: \
: "i" (hint), "R" (*(u8 *)(addr)))
static inline void cal_patgen(u32 start_addr, u32 size, u32 bias)
{
u32 *addr = (u32 *)start_addr;
int i;
for (i = 0; i < size; i++)
addr[i] = start_addr + i + bias;
}
static inline int test_loop(int k, int dqs, u32 test_dqs, u32 *coarse_dqs,
u32 offs, u32 pat, u32 val)
{
u32 nc_addr;
u32 *c_addr;
int i;
for (nc_addr = 0xa0000000;
nc_addr < (0xa0000000 + DRAM_BUTTOM - NUM_OF_CACHELINE * 32);
nc_addr += (DRAM_BUTTOM >> 6) + offs) {
writel(0x00007474, (void *)MT76XX_MEMCTRL_BASE + 0x64);
wmb(); /* Make sure store if finished */
c_addr = (u32 *)(nc_addr & 0xdfffffff);
cal_memset(((u8 *)c_addr), 0x1F, NUM_OF_CACHELINE * 32);
cal_patgen(nc_addr, NUM_OF_CACHELINE * 8, pat);
if (dqs > 0)
writel(0x00000074 |
(((k == 1) ? coarse_dqs[dqs] : test_dqs) << 12) |
(((k == 0) ? val : test_dqs) << 8),
(void *)MT76XX_MEMCTRL_BASE + 0x64);
else
writel(0x00007400 |
(((k == 1) ? coarse_dqs[dqs] : test_dqs) << 4) |
(((k == 0) ? val : test_dqs) << 0),
(void *)MT76XX_MEMCTRL_BASE + 0x64);
wmb(); /* Make sure store if finished */
invalidate_dcache_range((u32)c_addr,
(u32)c_addr +
NUM_OF_CACHELINE * 32);
wmb(); /* Make sure store if finished */
for (i = 0; i < NUM_OF_CACHELINE * 8; i++) {
if (i % 8 == 0)
pref_op(0, &c_addr[i]);
}
for (i = 0; i < NUM_OF_CACHELINE * 8; i++) {
if (c_addr[i] != nc_addr + i + pat)
return -1;
}
}
return 0;
}
void ddr_calibrate(void)
{
u32 min_coarse_dqs[2];
u32 max_coarse_dqs[2];
u32 min_fine_dqs[2];
u32 max_fine_dqs[2];
u32 coarse_dqs[2];
u32 fine_dqs[2];
int reg = 0, ddr_cfg2_reg;
int flag;
int i, k;
int dqs = 0;
u32 min_coarse_dqs_bnd, min_fine_dqs_bnd, coarse_dqs_dll, fine_dqs_dll;
u32 val;
u32 fdiv = 0, frac = 0;
/* Setup clock to run at full speed */
val = readl((void *)MT76XX_DYN_CFG0_REG);
fdiv = (u32)((val >> 8) & 0x0F);
if (CPU_FRAC_DIV < 1 || CPU_FRAC_DIV > 10)
frac = val & 0x0f;
else
frac = CPU_FRAC_DIV;
while (frac < fdiv) {
val = readl((void *)MT76XX_DYN_CFG0_REG);
fdiv = (val >> 8) & 0x0f;
fdiv--;
val &= ~(0x0f << 8);
val |= (fdiv << 8);
writel(val, (void *)MT76XX_DYN_CFG0_REG);
udelay(500);
val = readl((void *)MT76XX_DYN_CFG0_REG);
fdiv = (val >> 8) & 0x0f;
}
clrbits_le32((void *)MT76XX_MEMCTRL_BASE + 0x10, BIT(4));
ddr_cfg2_reg = readl((void *)MT76XX_MEMCTRL_BASE + 0x48);
clrbits_le32((void *)MT76XX_MEMCTRL_BASE + 0x48,
(0x3 << 28) | (0x3 << 26));
min_coarse_dqs[0] = MIN_START;
min_coarse_dqs[1] = MIN_START;
min_fine_dqs[0] = MIN_FINE_START;
min_fine_dqs[1] = MIN_FINE_START;
max_coarse_dqs[0] = MAX_START;
max_coarse_dqs[1] = MAX_START;
max_fine_dqs[0] = MAX_FINE_START;
max_fine_dqs[1] = MAX_FINE_START;
dqs = 0;
/* Add by KP, DQS MIN boundary */
reg = readl((void *)MT76XX_MEMCTRL_BASE + 0x20);
coarse_dqs_dll = (reg & 0xf00) >> 8;
fine_dqs_dll = (reg & 0xf0) >> 4;
if (coarse_dqs_dll <= 8)
min_coarse_dqs_bnd = 8 - coarse_dqs_dll;
else
min_coarse_dqs_bnd = 0;
if (fine_dqs_dll <= 8)
min_fine_dqs_bnd = 8 - fine_dqs_dll;
else
min_fine_dqs_bnd = 0;
/* DQS MIN boundary */
DQS_CAL:
for (k = 0; k < 2; k++) {
u32 test_dqs;
if (k == 0)
test_dqs = MAX_START;
else
test_dqs = MAX_FINE_START;
do {
flag = test_loop(k, dqs, test_dqs, max_coarse_dqs,
0x400, 0x3, 0xf);
if (flag == -1)
break;
test_dqs++;
} while (test_dqs <= 0xf);
if (k == 0) {
max_coarse_dqs[dqs] = test_dqs;
} else {
test_dqs--;
if (test_dqs == MAX_FINE_START - 1) {
max_coarse_dqs[dqs]--;
max_fine_dqs[dqs] = 0xf;
} else {
max_fine_dqs[dqs] = test_dqs;
}
}
}
for (k = 0; k < 2; k++) {
u32 test_dqs;
if (k == 0)
test_dqs = MIN_START;
else
test_dqs = MIN_FINE_START;
do {
flag = test_loop(k, dqs, test_dqs, min_coarse_dqs,
0x480, 0x1, 0x0);
if (k == 0) {
if (flag == -1 ||
test_dqs == min_coarse_dqs_bnd)
break;
test_dqs--;
if (test_dqs < min_coarse_dqs_bnd)
break;
} else {
if (flag == -1) {
test_dqs++;
break;
} else if (test_dqs == min_fine_dqs_bnd) {
break;
}
test_dqs--;
if (test_dqs < min_fine_dqs_bnd)
break;
}
} while (test_dqs >= 0);
if (k == 0) {
min_coarse_dqs[dqs] = test_dqs;
} else {
if (test_dqs == MIN_FINE_START + 1) {
min_coarse_dqs[dqs]++;
min_fine_dqs[dqs] = 0x0;
} else {
min_fine_dqs[dqs] = test_dqs;
}
}
}
if (dqs == 0) {
dqs = 1;
goto DQS_CAL;
}
for (i = 0; i < 2; i++) {
u32 temp;
coarse_dqs[i] = (max_coarse_dqs[i] + min_coarse_dqs[i]) >> 1;
temp =
(((max_coarse_dqs[i] + min_coarse_dqs[i]) % 2) * 4) +
((max_fine_dqs[i] + min_fine_dqs[i]) >> 1);
if (temp >= 0x10) {
coarse_dqs[i]++;
fine_dqs[i] = (temp - 0x10) + 0x8;
} else {
fine_dqs[i] = temp;
}
}
reg = (coarse_dqs[1] << 12) | (fine_dqs[1] << 8) |
(coarse_dqs[0] << 4) | fine_dqs[0];
clrbits_le32((void *)MT76XX_MEMCTRL_BASE + 0x10, BIT(4));
writel(reg, (void *)MT76XX_MEMCTRL_BASE + 0x64);
writel(ddr_cfg2_reg, (void *)MT76XX_MEMCTRL_BASE + 0x48);
setbits_le32((void *)MT76XX_MEMCTRL_BASE + 0x10, BIT(4));
for (i = 0; i < 2; i++)
debug("[%02X%02X%02X%02X]", min_coarse_dqs[i],
min_fine_dqs[i], max_coarse_dqs[i], max_fine_dqs[i]);
debug("\nDDR Calibration DQS reg = %08X\n", reg);
}