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/* 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;
}
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