diff options
| -rw-r--r-- | src/mainboard/google/dedede/variants/dibbi/Makefile.inc | 1 | ||||
| -rw-r--r-- | src/mainboard/google/dedede/variants/dibbi/ramstage.c | 35 |
2 files changed, 36 insertions, 0 deletions
diff --git a/src/mainboard/google/dedede/variants/dibbi/Makefile.inc b/src/mainboard/google/dedede/variants/dibbi/Makefile.inc index eb2c9bc021..66f0263c62 100644 --- a/src/mainboard/google/dedede/variants/dibbi/Makefile.inc +++ b/src/mainboard/google/dedede/variants/dibbi/Makefile.inc @@ -1,3 +1,4 @@ ## SPDX-License-Identifier: GPL-2.0-or-later ramstage-y += gpio.c +ramstage-y += ramstage.c diff --git a/src/mainboard/google/dedede/variants/dibbi/ramstage.c b/src/mainboard/google/dedede/variants/dibbi/ramstage.c new file mode 100644 index 0000000000..64510cc644 --- /dev/null +++ b/src/mainboard/google/dedede/variants/dibbi/ramstage.c @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ + +#include <baseboard/variants.h> + +/* + * Psys_pmax considerations + * + * Given the hardware design in dibbi, the serial shunt resistor is 0.01ohm. + * The full scale of hardware PSYS signal 1.6v maps to system current 6.009A + * instead of real system power. The equation is shown below: + * PSYS = 1.6v ~= (0.01ohm x 6.009A) x 50 (INA213, gain 50V/V) x R631/(R631 + R638) + * R631/(R631 + R638) = 0.5325 = 36K / (36K + 31.6K) + * + * The Psys_pmax is a SW setting which tells IMVP9.1 the mapping between system input + * current and the actual system power. Since there is no voltage information + * from PSYS, different voltage input would map to different Psys_pmax settings: + * For Type-C 15V, the Psys_pmax should be 15v x 6.009A = 90.135W + * For Type-C 20V, the Psys_pmax should be 20v x 6.009A = 120.18W + * For a barrel jack, the Psys_pmax should be 19v x 6.009A = 114.171W + * + * Imagine that there is a type-c 100W (20V/5A) connected to DUT w/ full loading, + * and the Psys_pmax setting is 120W. Then IMVP9.1 can calculate the current system + * power = 120W * 5A / 6.009A = 100W, which is the actual system power. + */ +const struct psys_config psys_config = { + .efficiency = 97, + .psys_imax_ma = 6009, + .bj_volts_mv = 19000, + .bj_power_w = 65, +}; + +void variant_devtree_update(void) +{ + variant_update_psys_power_limits(&psys_config); +} |