diff options
Diffstat (limited to 'arch/mips/mach-mt7620/ddr_calibrate.c')
| -rw-r--r-- | arch/mips/mach-mt7620/ddr_calibrate.c | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/arch/mips/mach-mt7620/ddr_calibrate.c b/arch/mips/mach-mt7620/ddr_calibrate.c new file mode 100644 index 0000000000..75763c4528 --- /dev/null +++ b/arch/mips/mach-mt7620/ddr_calibrate.c @@ -0,0 +1,308 @@ +// 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 <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); +} |