1 /* SPDX-License-Identifier: GPL-2.0-only */
2
3 #include <console/console.h>
4 #include <device/device.h>
5 #include <device/dram/lpddr4.h>
6 #include <memory_info.h>
7 #include <smbios.h>
8 #include <types.h>
9
10 enum lpddr4_speed_grade {
11 LPDDR4_1333,
12 LPDDR4_1600,
13 LPDDR4_1866,
14 LPDDR4_2133,
15 LPDDR4_2400,
16 LPDDR4_2666,
17 LPDDR4_3200,
18 LPDDR4_3733,
19 LPDDR4_4266,
20 };
21
22 struct lpddr4_speed_attr {
23 uint32_t min_clock_mhz; // inclusive
24 uint32_t max_clock_mhz; // inclusive
25 uint32_t reported_mts;
26 };
27
28 /**
29 * LPDDR4 speed attributes derived from JEDEC 209-4C and industry norms
30 *
31 * min_clock_mhz = Previous max_clock_mhz + 1
32 * max_clock_mhz = 1000/min_tCk_avg(ns)
33 * reported_mts = Standard reported DDR4 speed in MT/s
34 * May be slightly less than the actual max MT/s
35 */
36 static const struct lpddr4_speed_attr lpddr4_speeds[] = {
37 [LPDDR4_1333] = {
38 .min_clock_mhz = 10,
39 .max_clock_mhz = 667,
40 .reported_mts = 1333,
41 },
42 [LPDDR4_1600] = {
43 .min_clock_mhz = 668,
44 .max_clock_mhz = 800,
45 .reported_mts = 1600
46 },
47 [LPDDR4_1866] = {
48 .min_clock_mhz = 801,
49 .max_clock_mhz = 934,
50 .reported_mts = 1866,
51 },
52 [LPDDR4_2133] = {
53 .min_clock_mhz = 935,
54 .max_clock_mhz = 1067,
55 .reported_mts = 2133
56 },
57 [LPDDR4_2400] = {
58 .min_clock_mhz = 1068,
59 .max_clock_mhz = 1200,
60 .reported_mts = 2400
61 },
62 [LPDDR4_2666] = {
63 .min_clock_mhz = 1201,
64 .max_clock_mhz = 1333,
65 .reported_mts = 2666
66 },
67 [LPDDR4_3200] = {
68 .min_clock_mhz = 1334,
69 .max_clock_mhz = 1600,
70 .reported_mts = 3200
71 },
72 [LPDDR4_3733] = {
73 .min_clock_mhz = 1601,
74 .max_clock_mhz = 1867,
75 .reported_mts = 3733
76 },
77 [LPDDR4_4266] = {
78 .min_clock_mhz = 1868,
79 .max_clock_mhz = 2134,
80 .reported_mts = 4266
81 },
82 };
83
84 /**
85 * Converts LPDDR4 clock speed in MHz to the standard reported speed in MT/s
86 */
lpddr4_speed_mhz_to_reported_mts(uint16_t speed_mhz)87 uint16_t lpddr4_speed_mhz_to_reported_mts(uint16_t speed_mhz)
88 {
89 for (enum lpddr4_speed_grade speed = 0; speed < ARRAY_SIZE(lpddr4_speeds); speed++) {
90 const struct lpddr4_speed_attr *speed_attr = &lpddr4_speeds[speed];
91 if (speed_mhz >= speed_attr->min_clock_mhz &&
92 speed_mhz <= speed_attr->max_clock_mhz) {
93 return speed_attr->reported_mts;
94 }
95 }
96 printk(BIOS_ERR, "LPDDR4 speed of %d MHz is out of range\n", speed_mhz);
97 return 0;
98 }
99