236 lines
7.0 KiB
C
236 lines
7.0 KiB
C
/*
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* Utility functions for parsing Tegra CVB voltage tables
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*
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* Copyright (C) 2012-2014 NVIDIA Corporation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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*/
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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <linux/pm_opp.h>
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#include <soc/tegra/cvb.h>
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/* cvb_mv = ((c2 * speedo / s_scale + c1) * speedo / s_scale + c0) */
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int tegra_get_cvb_voltage(int speedo, int s_scale,
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const struct cvb_coefficients *cvb)
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{
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int mv;
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/* apply only speedo scale: output mv = cvb_mv * v_scale */
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mv = DIV_ROUND_CLOSEST(cvb->c2 * speedo, s_scale);
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mv = DIV_ROUND_CLOSEST((mv + cvb->c1) * speedo, s_scale) + cvb->c0;
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return mv;
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}
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/* cvb_t_mv =
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((c3 * speedo / s_scale + c4 + c5 * T / t_scale) * T / t_scale) / v_scale */
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int tegra_get_cvb_t_voltage(int speedo, int s_scale, int t, int t_scale,
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struct cvb_coefficients *cvb)
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{
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/* apply speedo & temperature scales: output mv = cvb_t_mv * v_scale */
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int mv;
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mv = DIV_ROUND_CLOSEST(cvb->c3 * speedo, s_scale) + cvb->c4 +
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DIV_ROUND_CLOSEST(cvb->c5 * t, t_scale);
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mv = DIV_ROUND_CLOSEST(mv * t, t_scale);
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return mv;
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}
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int tegra_round_cvb_voltage(int mv, int v_scale,
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const struct rail_alignment *align)
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{
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/* combined: apply voltage scale and round to cvb alignment step */
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int uv;
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int step = (align->step_uv ? : 1000) * v_scale;
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int offset = align->offset_uv * v_scale;
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uv = max(mv * 1000, offset) - offset;
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uv = DIV_ROUND_UP(uv, step) * align->step_uv + align->offset_uv;
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return uv / 1000;
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}
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enum {
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DOWN,
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UP
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};
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int tegra_round_voltage(int mv, const struct rail_alignment *align, int up)
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{
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if (align->step_uv) {
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int uv;
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uv = max(mv * 1000, align->offset_uv) - align->offset_uv;
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uv = (uv + (up ? align->step_uv - 1 : 0)) / align->step_uv;
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return (uv * align->step_uv + align->offset_uv) / 1000;
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}
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return mv;
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}
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/**
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* cvb_t_mv =
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* ((c2 * speedo / s_scale + c1) * speedo / s_scale + c0) +
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* ((c3 * speedo / s_scale + c4 + c5 * T / t_scale) * T / t_scale)
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*/
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static inline int get_cvb_thermal_floor(int speedo, int temp,
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int s_scale, int t_scale,
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const struct thermal_coefficients *coef)
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{
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int cvb_mv, mv;
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cvb_mv = tegra_get_cvb_voltage(speedo, s_scale, &coef->cvb_coef);
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mv = DIV_ROUND_CLOSEST(coef->c3 * speedo, s_scale) + coef->c4 +
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DIV_ROUND_CLOSEST(coef->c5 * temp, t_scale);
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mv = DIV_ROUND_CLOSEST(mv * temp, t_scale) + cvb_mv;
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return mv;
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}
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static int build_opp_table(struct device *dev, const struct cvb_table *table,
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struct rail_alignment *align,
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int speedo_value, unsigned long max_freq, int *vmin)
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{
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int i, ret, dfll_mv, min_mv, max_mv;
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if (!align->step_uv)
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align->step_uv = table->alignment.step_uv;
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if (!align->step_uv)
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return -EINVAL;
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if (!align->offset_uv)
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align->offset_uv = table->alignment.offset_uv;
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min_mv = tegra_round_voltage(table->min_millivolts, align, UP);
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max_mv = tegra_round_voltage(table->max_millivolts, align, DOWN);
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dfll_mv = tegra_get_cvb_voltage(
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speedo_value, table->speedo_scale, &table->vmin_coefficients);
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dfll_mv = tegra_round_cvb_voltage(dfll_mv, table->voltage_scale, align);
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min_mv = max(min_mv, dfll_mv);
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for (i = 0; i < MAX_DVFS_FREQS; i++) {
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const struct cvb_table_freq_entry *entry = &table->entries[i];
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if (!entry->freq || (entry->freq > max_freq))
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break;
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dfll_mv = tegra_get_cvb_voltage(
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speedo_value, table->speedo_scale, &entry->coefficients);
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dfll_mv = tegra_round_cvb_voltage(dfll_mv, table->voltage_scale, align);
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dfll_mv = clamp(dfll_mv, min_mv, max_mv);
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ret = dev_pm_opp_add(dev, entry->freq, dfll_mv * 1000);
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if (ret)
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return ret;
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}
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if (vmin)
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*vmin = min_mv;
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return 0;
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}
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/**
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* tegra_cvb_add_opp_table - build OPP table from Tegra CVB tables
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* @cvb_tables: array of CVB tables
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* @sz: size of the previously mentioned array
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* @process_id: process id of the HW module
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* @speedo_id: speedo id of the HW module
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* @speedo_value: speedo value of the HW module
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* @max_rate: highest safe clock rate
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* @opp_dev: the struct device * for which the OPP table is built
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* @vmin: final minimum voltage returned to the caller
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*
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* On Tegra, a CVB table encodes the relationship between operating voltage
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* and safe maximal frequency for a given module (e.g. GPU or CPU). This
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* function calculates the optimal voltage-frequency operating points
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* for the given arguments and exports them via the OPP library for the
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* given @opp_dev. Returns a pointer to the struct cvb_table that matched
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* or an ERR_PTR on failure.
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*/
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const struct cvb_table *
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tegra_cvb_add_opp_table(struct device *dev, const struct cvb_table *tables,
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size_t count, struct rail_alignment *align,
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int process_id, int speedo_id, int speedo_value,
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unsigned long max_freq, int *vmin)
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{
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size_t i;
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int ret;
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for (i = 0; i < count; i++) {
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const struct cvb_table *table = &tables[i];
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if (table->speedo_id != -1 && table->speedo_id != speedo_id)
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continue;
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if (table->process_id != -1 && table->process_id != process_id)
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continue;
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ret = build_opp_table(dev, table, align, speedo_value,
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max_freq, vmin);
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return ret ? ERR_PTR(ret) : table;
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}
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return ERR_PTR(-EINVAL);
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}
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void tegra_cvb_remove_opp_table(struct device *dev,
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const struct cvb_table *table,
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unsigned long max_freq)
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{
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unsigned int i;
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for (i = 0; i < MAX_DVFS_FREQS; i++) {
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const struct cvb_table_freq_entry *entry = &table->entries[i];
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if (!entry->freq || (entry->freq > max_freq))
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break;
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dev_pm_opp_remove(dev, entry->freq);
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}
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}
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/**
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* tegra_cvb_build_thermal_table - build thermal table from Tegra CVB tables
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* @table: the hardware characterization thermal table
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* @speedo_value: speedo value of the HW module
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* @soc_min_mv: minimum voltage applied across all temperature ranges
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*
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* The minimum voltage for the IP blocks inside Tegra SoCs might depend on
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* the current temperature. This function calculates the voltage-thermal
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* relations according to the given coefficients. Note that if the
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* coefficients are not defined, the fixed thermal floors in the @table will
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* be used. Returns 0 on success or a negative error code on failure.
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*/
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int tegra_cvb_build_thermal_table(const struct thermal_table *table,
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int speedo_value, unsigned int soc_min_mv)
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{
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int i;
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if (!table)
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return -EINVAL;
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/* The vmin for the lowest trip point is fixed */
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for (i = 1; i < table->thermal_floor_table_size; i++) {
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unsigned int mv;
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mv = get_cvb_thermal_floor(speedo_value,
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table->thermal_floor_table[i-1].temp,
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table->speedo_scale,
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table->temp_scale,
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&table->coefficients);
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mv = DIV_ROUND_UP(mv, table->voltage_scale);
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mv = max(mv, soc_min_mv);
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table->thermal_floor_table[i].millivolts = max(mv,
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table->thermal_floor_table[i].millivolts);
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}
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return 0;
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}
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