linux/drivers/cpufreq/tegra186-cpufreq.c
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   1/*
   2 * Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved
   3 *
   4 * This program is free software; you can redistribute it and/or modify it
   5 * under the terms and conditions of the GNU General Public License,
   6 * version 2, as published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope it will be useful, but WITHOUT
   9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11 * more details.
  12 */
  13
  14#include <linux/cpufreq.h>
  15#include <linux/dma-mapping.h>
  16#include <linux/module.h>
  17#include <linux/of.h>
  18#include <linux/platform_device.h>
  19
  20#include <soc/tegra/bpmp.h>
  21#include <soc/tegra/bpmp-abi.h>
  22
  23#define EDVD_CORE_VOLT_FREQ(core)               (0x20 + (core) * 0x4)
  24#define EDVD_CORE_VOLT_FREQ_F_SHIFT             0
  25#define EDVD_CORE_VOLT_FREQ_V_SHIFT             16
  26
  27struct tegra186_cpufreq_cluster_info {
  28        unsigned long offset;
  29        int cpus[4];
  30        unsigned int bpmp_cluster_id;
  31};
  32
  33#define NO_CPU -1
  34static const struct tegra186_cpufreq_cluster_info tegra186_clusters[] = {
  35        /* Denver cluster */
  36        {
  37                .offset = SZ_64K * 7,
  38                .cpus = { 1, 2, NO_CPU, NO_CPU },
  39                .bpmp_cluster_id = 0,
  40        },
  41        /* A57 cluster */
  42        {
  43                .offset = SZ_64K * 6,
  44                .cpus = { 0, 3, 4, 5 },
  45                .bpmp_cluster_id = 1,
  46        },
  47};
  48
  49struct tegra186_cpufreq_cluster {
  50        const struct tegra186_cpufreq_cluster_info *info;
  51        struct cpufreq_frequency_table *table;
  52};
  53
  54struct tegra186_cpufreq_data {
  55        void __iomem *regs;
  56
  57        size_t num_clusters;
  58        struct tegra186_cpufreq_cluster *clusters;
  59};
  60
  61static int tegra186_cpufreq_init(struct cpufreq_policy *policy)
  62{
  63        struct tegra186_cpufreq_data *data = cpufreq_get_driver_data();
  64        unsigned int i;
  65
  66        for (i = 0; i < data->num_clusters; i++) {
  67                struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
  68                const struct tegra186_cpufreq_cluster_info *info =
  69                        cluster->info;
  70                int core;
  71
  72                for (core = 0; core < ARRAY_SIZE(info->cpus); core++) {
  73                        if (info->cpus[core] == policy->cpu)
  74                                break;
  75                }
  76                if (core == ARRAY_SIZE(info->cpus))
  77                        continue;
  78
  79                policy->driver_data =
  80                        data->regs + info->offset + EDVD_CORE_VOLT_FREQ(core);
  81                policy->freq_table = cluster->table;
  82                break;
  83        }
  84
  85        policy->cpuinfo.transition_latency = 300 * 1000;
  86
  87        return 0;
  88}
  89
  90static int tegra186_cpufreq_set_target(struct cpufreq_policy *policy,
  91                                       unsigned int index)
  92{
  93        struct cpufreq_frequency_table *tbl = policy->freq_table + index;
  94        void __iomem *edvd_reg = policy->driver_data;
  95        u32 edvd_val = tbl->driver_data;
  96
  97        writel(edvd_val, edvd_reg);
  98
  99        return 0;
 100}
 101
 102static struct cpufreq_driver tegra186_cpufreq_driver = {
 103        .name = "tegra186",
 104        .flags = CPUFREQ_STICKY | CPUFREQ_HAVE_GOVERNOR_PER_POLICY,
 105        .verify = cpufreq_generic_frequency_table_verify,
 106        .target_index = tegra186_cpufreq_set_target,
 107        .init = tegra186_cpufreq_init,
 108        .attr = cpufreq_generic_attr,
 109};
 110
 111static struct cpufreq_frequency_table *init_vhint_table(
 112        struct platform_device *pdev, struct tegra_bpmp *bpmp,
 113        unsigned int cluster_id)
 114{
 115        struct cpufreq_frequency_table *table;
 116        struct mrq_cpu_vhint_request req;
 117        struct tegra_bpmp_message msg;
 118        struct cpu_vhint_data *data;
 119        int err, i, j, num_rates = 0;
 120        dma_addr_t phys;
 121        void *virt;
 122
 123        virt = dma_alloc_coherent(bpmp->dev, sizeof(*data), &phys,
 124                                  GFP_KERNEL | GFP_DMA32);
 125        if (!virt)
 126                return ERR_PTR(-ENOMEM);
 127
 128        data = (struct cpu_vhint_data *)virt;
 129
 130        memset(&req, 0, sizeof(req));
 131        req.addr = phys;
 132        req.cluster_id = cluster_id;
 133
 134        memset(&msg, 0, sizeof(msg));
 135        msg.mrq = MRQ_CPU_VHINT;
 136        msg.tx.data = &req;
 137        msg.tx.size = sizeof(req);
 138
 139        err = tegra_bpmp_transfer(bpmp, &msg);
 140        if (err) {
 141                table = ERR_PTR(err);
 142                goto free;
 143        }
 144
 145        for (i = data->vfloor; i <= data->vceil; i++) {
 146                u16 ndiv = data->ndiv[i];
 147
 148                if (ndiv < data->ndiv_min || ndiv > data->ndiv_max)
 149                        continue;
 150
 151                /* Only store lowest voltage index for each rate */
 152                if (i > 0 && ndiv == data->ndiv[i - 1])
 153                        continue;
 154
 155                num_rates++;
 156        }
 157
 158        table = devm_kcalloc(&pdev->dev, num_rates + 1, sizeof(*table),
 159                             GFP_KERNEL);
 160        if (!table) {
 161                table = ERR_PTR(-ENOMEM);
 162                goto free;
 163        }
 164
 165        for (i = data->vfloor, j = 0; i <= data->vceil; i++) {
 166                struct cpufreq_frequency_table *point;
 167                u16 ndiv = data->ndiv[i];
 168                u32 edvd_val = 0;
 169
 170                if (ndiv < data->ndiv_min || ndiv > data->ndiv_max)
 171                        continue;
 172
 173                /* Only store lowest voltage index for each rate */
 174                if (i > 0 && ndiv == data->ndiv[i - 1])
 175                        continue;
 176
 177                edvd_val |= i << EDVD_CORE_VOLT_FREQ_V_SHIFT;
 178                edvd_val |= ndiv << EDVD_CORE_VOLT_FREQ_F_SHIFT;
 179
 180                point = &table[j++];
 181                point->driver_data = edvd_val;
 182                point->frequency = data->ref_clk_hz * ndiv / data->pdiv /
 183                        data->mdiv / 1000;
 184        }
 185
 186        table[j].frequency = CPUFREQ_TABLE_END;
 187
 188free:
 189        dma_free_coherent(bpmp->dev, sizeof(*data), virt, phys);
 190
 191        return table;
 192}
 193
 194static int tegra186_cpufreq_probe(struct platform_device *pdev)
 195{
 196        struct tegra186_cpufreq_data *data;
 197        struct tegra_bpmp *bpmp;
 198        struct resource *res;
 199        unsigned int i = 0, err;
 200
 201        data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 202        if (!data)
 203                return -ENOMEM;
 204
 205        data->clusters = devm_kcalloc(&pdev->dev, ARRAY_SIZE(tegra186_clusters),
 206                                      sizeof(*data->clusters), GFP_KERNEL);
 207        if (!data->clusters)
 208                return -ENOMEM;
 209
 210        data->num_clusters = ARRAY_SIZE(tegra186_clusters);
 211
 212        bpmp = tegra_bpmp_get(&pdev->dev);
 213        if (IS_ERR(bpmp))
 214                return PTR_ERR(bpmp);
 215
 216        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 217        data->regs = devm_ioremap_resource(&pdev->dev, res);
 218        if (IS_ERR(data->regs)) {
 219                err = PTR_ERR(data->regs);
 220                goto put_bpmp;
 221        }
 222
 223        for (i = 0; i < data->num_clusters; i++) {
 224                struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
 225
 226                cluster->info = &tegra186_clusters[i];
 227                cluster->table = init_vhint_table(
 228                        pdev, bpmp, cluster->info->bpmp_cluster_id);
 229                if (IS_ERR(cluster->table)) {
 230                        err = PTR_ERR(cluster->table);
 231                        goto put_bpmp;
 232                }
 233        }
 234
 235        tegra_bpmp_put(bpmp);
 236
 237        tegra186_cpufreq_driver.driver_data = data;
 238
 239        err = cpufreq_register_driver(&tegra186_cpufreq_driver);
 240        if (err)
 241                return err;
 242
 243        return 0;
 244
 245put_bpmp:
 246        tegra_bpmp_put(bpmp);
 247
 248        return err;
 249}
 250
 251static int tegra186_cpufreq_remove(struct platform_device *pdev)
 252{
 253        cpufreq_unregister_driver(&tegra186_cpufreq_driver);
 254
 255        return 0;
 256}
 257
 258static const struct of_device_id tegra186_cpufreq_of_match[] = {
 259        { .compatible = "nvidia,tegra186-ccplex-cluster", },
 260        { }
 261};
 262MODULE_DEVICE_TABLE(of, tegra186_cpufreq_of_match);
 263
 264static struct platform_driver tegra186_cpufreq_platform_driver = {
 265        .driver = {
 266                .name = "tegra186-cpufreq",
 267                .of_match_table = tegra186_cpufreq_of_match,
 268        },
 269        .probe = tegra186_cpufreq_probe,
 270        .remove = tegra186_cpufreq_remove,
 271};
 272module_platform_driver(tegra186_cpufreq_platform_driver);
 273
 274MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
 275MODULE_DESCRIPTION("NVIDIA Tegra186 cpufreq driver");
 276MODULE_LICENSE("GPL v2");
 277