| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <console/console.h> |
| #include <cbmem.h> |
| #include <device/device.h> |
| #include <device/dram/lpddr4.h> |
| #include <string.h> |
| #include <memory_info.h> |
| #include <smbios.h> |
| #include <types.h> |
| |
| enum lpddr4_speed_grade { |
| LPDDR4_1600, |
| LPDDR4_2400, |
| LPDDR4_3200, |
| LPDDR4_4266 |
| }; |
| |
| struct lpddr4_speed_attr { |
| uint32_t min_clock_mhz; // inclusive |
| uint32_t max_clock_mhz; // inclusive |
| uint32_t reported_mts; |
| }; |
| |
| /** |
| * LPDDR4 speed attributes derived from JEDEC 209-4C table 210 |
| * |
| * min_clock_mhz = Previous max_clock_mhz + 1 |
| * max_clock_mhz = 1000/min_tCk_avg(ns) |
| * reported_mts = Standard reported DDR4 speed in MT/s |
| * May be slightly less than the actual max MT/s |
| */ |
| static const struct lpddr4_speed_attr lpddr4_speeds[] = { |
| [LPDDR4_1600] = { |
| .min_clock_mhz = 10, |
| .max_clock_mhz = 800, |
| .reported_mts = 1600 |
| }, |
| [LPDDR4_2400] = { |
| .min_clock_mhz = 801, |
| .max_clock_mhz = 1200, |
| .reported_mts = 2400 |
| }, |
| [LPDDR4_3200] = { |
| .min_clock_mhz = 1201, |
| .max_clock_mhz = 1600, |
| .reported_mts = 3200 |
| }, |
| [LPDDR4_4266] = { |
| .min_clock_mhz = 1601, |
| .max_clock_mhz = 2137, |
| .reported_mts = 4266 |
| }, |
| }; |
| |
| /** |
| * Converts LPDDR4 clock speed in MHz to the standard reported speed in MT/s |
| */ |
| uint16_t lpddr4_speed_mhz_to_reported_mts(uint16_t speed_mhz) |
| { |
| for (enum lpddr4_speed_grade speed = 0; speed < ARRAY_SIZE(lpddr4_speeds); speed++) { |
| const struct lpddr4_speed_attr *speed_attr = &lpddr4_speeds[speed]; |
| if (speed_mhz >= speed_attr->min_clock_mhz && |
| speed_mhz <= speed_attr->max_clock_mhz) { |
| return speed_attr->reported_mts; |
| } |
| } |
| printk(BIOS_ERR, "ERROR: LPDDR4 speed of %d MHz is out of range", speed_mhz); |
| return 0; |
| } |