diff options
Diffstat (limited to 'drivers/regulator/cpr3-util.c')
| -rw-r--r-- | drivers/regulator/cpr3-util.c | 101 |
1 files changed, 92 insertions, 9 deletions
diff --git a/drivers/regulator/cpr3-util.c b/drivers/regulator/cpr3-util.c index 51179f28fcf5..c377a65a6393 100644 --- a/drivers/regulator/cpr3-util.c +++ b/drivers/regulator/cpr3-util.c @@ -1202,6 +1202,23 @@ int cpr3_parse_common_ctrl_data(struct cpr3_controller *ctrl) if (rc) return rc; + ctrl->vdd_regulator = devm_regulator_get(ctrl->dev, "vdd"); + if (IS_ERR(ctrl->vdd_regulator)) { + rc = PTR_ERR(ctrl->vdd_regulator); + if (rc != -EPROBE_DEFER) { + /* vdd-supply is optional for CPRh controllers. */ + if (ctrl->ctrl_type == CPR_CTRL_TYPE_CPRH) { + cpr3_debug(ctrl, "unable to request vdd regulator, rc=%d\n", + rc); + ctrl->vdd_regulator = NULL; + return 0; + } + cpr3_err(ctrl, "unable to request vdd regulator, rc=%d\n", + rc); + } + return rc; + } + /* * Regulator device handles are not necessary for CPRh controllers * since communication with the regulators is completely managed @@ -1210,15 +1227,6 @@ int cpr3_parse_common_ctrl_data(struct cpr3_controller *ctrl) if (ctrl->ctrl_type == CPR_CTRL_TYPE_CPRH) return rc; - ctrl->vdd_regulator = devm_regulator_get(ctrl->dev, "vdd"); - if (IS_ERR(ctrl->vdd_regulator)) { - rc = PTR_ERR(ctrl->vdd_regulator); - if (rc != -EPROBE_DEFER) - cpr3_err(ctrl, "unable request vdd regulator, rc=%d\n", - rc); - return rc; - } - ctrl->system_regulator = devm_regulator_get_optional(ctrl->dev, "system"); if (IS_ERR(ctrl->system_regulator)) { @@ -2000,3 +2008,78 @@ done: return rc; } + +/** + * cprh_adjust_voltages_for_apm() - adjust per-corner floor and ceiling voltages + * so that they do not overlap the APM threshold voltage. + * @vreg: Pointer to the CPR3 regulator + * + * The memory array power mux (APM) must be configured for a specific supply + * based upon where the VDD voltage lies with respect to the APM threshold + * voltage. When using CPR hardware closed-loop, the voltage may vary anywhere + * between the floor and ceiling voltage without software notification. + * Therefore, it is required that the floor to ceiling range for every corner + * not intersect the APM threshold voltage. This function adjusts the floor to + * ceiling range for each corner which violates this requirement. + * + * The following algorithm is applied: + * if floor < threshold <= ceiling: + * if open_loop >= threshold, then floor = threshold - adj + * else ceiling = threshold - step + * where: + * adj = APM hysteresis voltage established to minimize the number of + * corners with artificially increased floor voltages + * step = voltage in microvolts of a single step of the VDD supply + * + * The open-loop voltage is also bounded by the new floor or ceiling value as + * needed. + * + * Return: none + */ +void cprh_adjust_voltages_for_apm(struct cpr3_regulator *vreg) +{ + struct cpr3_controller *ctrl = vreg->thread->ctrl; + struct cpr3_corner *corner; + int i, adj, threshold, prev_ceiling, prev_floor, prev_open_loop; + + if (!ctrl->apm_threshold_volt) { + /* APM not being used. */ + return; + } + + ctrl->apm_threshold_volt = CPR3_ROUND(ctrl->apm_threshold_volt, + ctrl->step_volt); + ctrl->apm_adj_volt = CPR3_ROUND(ctrl->apm_adj_volt, ctrl->step_volt); + + threshold = ctrl->apm_threshold_volt; + adj = ctrl->apm_adj_volt; + + for (i = 0; i < vreg->corner_count; i++) { + corner = &vreg->corner[i]; + + if (threshold <= corner->floor_volt + || threshold > corner->ceiling_volt) + continue; + + prev_floor = corner->floor_volt; + prev_ceiling = corner->ceiling_volt; + prev_open_loop = corner->open_loop_volt; + + if (corner->open_loop_volt >= threshold) { + corner->floor_volt = max(corner->floor_volt, + threshold - adj); + if (corner->open_loop_volt < corner->floor_volt) + corner->open_loop_volt = corner->floor_volt; + } else { + corner->ceiling_volt = threshold - ctrl->step_volt; + } + + if (corner->floor_volt != prev_floor + || corner->ceiling_volt != prev_ceiling + || corner->open_loop_volt != prev_open_loop) + cpr3_debug(vreg, "APM threshold=%d, APM adj=%d changed corner %d voltages; prev: floor=%d, ceiling=%d, open-loop=%d; new: floor=%d, ceiling=%d, open-loop=%d\n", + threshold, adj, i, prev_floor, prev_ceiling, + prev_open_loop, corner->floor_volt, + corner->ceiling_volt, corner->open_loop_volt); + } +} |