drivers/cpufreq/tegra186-cpufreq.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved
   4  */
   5
   6 #include <linux/cpufreq.h>
   7 #include <linux/dma-mapping.h>
   8 #include <linux/module.h>
   9 #include <linux/of.h>
  10 #include <linux/platform_device.h>
  11
  12 #include <soc/tegra/bpmp.h>
  13 #include <soc/tegra/bpmp-abi.h>
  14
  15 #define EDVD_CORE_VOLT_FREQ(core)               (0x20 + (core) * 0x4)
  16 #define EDVD_CORE_VOLT_FREQ_F_SHIFT             0
  17 #define EDVD_CORE_VOLT_FREQ_V_SHIFT             16
  18
  19 struct tegra186_cpufreq_cluster_info {
  20         unsigned long offset;
  21         int cpus[4];
  22         unsigned int bpmp_cluster_id;
  23 };
  24
  25 #define NO_CPU -1
  26 static const struct tegra186_cpufreq_cluster_info tegra186_clusters[] = {
  27         /* Denver cluster */
  28         {
  29                 .offset = SZ_64K * 7,
  30                 .cpus = { 1, 2, NO_CPU, NO_CPU },
  31                 .bpmp_cluster_id = 0,
  32         },
  33         /* A57 cluster */
  34         {
  35                 .offset = SZ_64K * 6,
  36                 .cpus = { 0, 3, 4, 5 },
  37                 .bpmp_cluster_id = 1,
  38         },
  39 };
  40
  41 struct tegra186_cpufreq_cluster {
  42         const struct tegra186_cpufreq_cluster_info *info;
  43         struct cpufreq_frequency_table *table;
  44 };
  45
  46 struct tegra186_cpufreq_data {
  47         void __iomem *regs;
  48
  49         size_t num_clusters;
  50         struct tegra186_cpufreq_cluster *clusters;
  51 };
  52
  53 static int tegra186_cpufreq_init(struct cpufreq_policy *policy)
  54 {
  55         struct tegra186_cpufreq_data *data = cpufreq_get_driver_data();
  56         unsigned int i;
  57
  58         for (i = 0; i < data->num_clusters; i++) {
  59                 struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
  60                 const struct tegra186_cpufreq_cluster_info *info =
  61                         cluster->info;
  62                 int core;
  63
  64                 for (core = 0; core < ARRAY_SIZE(info->cpus); core++) {
  65                         if (info->cpus[core] == policy->cpu)
  66                                 break;
  67                 }
  68                 if (core == ARRAY_SIZE(info->cpus))
  69                         continue;
  70
  71                 policy->driver_data =
  72                         data->regs + info->offset + EDVD_CORE_VOLT_FREQ(core);
  73                 policy->freq_table = cluster->table;
  74                 break;
  75         }
  76
  77         policy->cpuinfo.transition_latency = 300 * 1000;
  78
  79         return 0;
  80 }
  81
  82 static int tegra186_cpufreq_set_target(struct cpufreq_policy *policy,
  83                                        unsigned int index)
  84 {
  85         struct cpufreq_frequency_table *tbl = policy->freq_table + index;
  86         void __iomem *edvd_reg = policy->driver_data;
  87         u32 edvd_val = tbl->driver_data;
  88
  89         writel(edvd_val, edvd_reg);
  90
  91         return 0;
  92 }
  93
  94 static struct cpufreq_driver tegra186_cpufreq_driver = {
  95         .name = "tegra186",
  96         .flags = CPUFREQ_STICKY | CPUFREQ_HAVE_GOVERNOR_PER_POLICY,
  97         .verify = cpufreq_generic_frequency_table_verify,
  98         .target_index = tegra186_cpufreq_set_target,
  99         .init = tegra186_cpufreq_init,
 100         .attr = cpufreq_generic_attr,
 101 };
 102
 103 static struct cpufreq_frequency_table *init_vhint_table(
 104         struct platform_device *pdev, struct tegra_bpmp *bpmp,
 105         unsigned int cluster_id)
 106 {
 107         struct cpufreq_frequency_table *table;
 108         struct mrq_cpu_vhint_request req;
 109         struct tegra_bpmp_message msg;
 110         struct cpu_vhint_data *data;
 111         int err, i, j, num_rates = 0;
 112         dma_addr_t phys;
 113         void *virt;
 114
 115         virt = dma_alloc_coherent(bpmp->dev, sizeof(*data), &phys,
 116                                   GFP_KERNEL);
 117         if (!virt)
 118                 return ERR_PTR(-ENOMEM);
 119
 120         data = (struct cpu_vhint_data *)virt;
 121
 122         memset(&req, 0, sizeof(req));
 123         req.addr = phys;
 124         req.cluster_id = cluster_id;
 125
 126         memset(&msg, 0, sizeof(msg));
 127         msg.mrq = MRQ_CPU_VHINT;
 128         msg.tx.data = &req;
 129         msg.tx.size = sizeof(req);
 130
 131         err = tegra_bpmp_transfer(bpmp, &msg);
 132         if (err) {
 133                 table = ERR_PTR(err);
 134                 goto free;
 135         }
 136
 137         for (i = data->vfloor; i <= data->vceil; i++) {
 138                 u16 ndiv = data->ndiv[i];
 139
 140                 if (ndiv < data->ndiv_min || ndiv > data->ndiv_max)
 141                         continue;
 142
 143                 /* Only store lowest voltage index for each rate */
 144                 if (i > 0 && ndiv == data->ndiv[i - 1])
 145                         continue;
 146
 147                 num_rates++;
 148         }
 149
 150         table = devm_kcalloc(&pdev->dev, num_rates + 1, sizeof(*table),
 151                              GFP_KERNEL);
 152         if (!table) {
 153                 table = ERR_PTR(-ENOMEM);
 154                 goto free;
 155         }
 156
 157         for (i = data->vfloor, j = 0; i <= data->vceil; i++) {
 158                 struct cpufreq_frequency_table *point;
 159                 u16 ndiv = data->ndiv[i];
 160                 u32 edvd_val = 0;
 161
 162                 if (ndiv < data->ndiv_min || ndiv > data->ndiv_max)
 163                         continue;
 164
 165                 /* Only store lowest voltage index for each rate */
 166                 if (i > 0 && ndiv == data->ndiv[i - 1])
 167                         continue;
 168
 169                 edvd_val |= i << EDVD_CORE_VOLT_FREQ_V_SHIFT;
 170                 edvd_val |= ndiv << EDVD_CORE_VOLT_FREQ_F_SHIFT;
 171
 172                 point = &table[j++];
 173                 point->driver_data = edvd_val;
 174                 point->frequency = data->ref_clk_hz * ndiv / data->pdiv /
 175                         data->mdiv / 1000;
 176         }
 177
 178         table[j].frequency = CPUFREQ_TABLE_END;
 179
 180 free:
 181         dma_free_coherent(bpmp->dev, sizeof(*data), virt, phys);
 182
 183         return table;
 184 }
 185
 186 static int tegra186_cpufreq_probe(struct platform_device *pdev)
 187 {
 188         struct tegra186_cpufreq_data *data;
 189         struct tegra_bpmp *bpmp;
 190         struct resource *res;
 191         unsigned int i = 0, err;
 192
 193         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 194         if (!data)
 195                 return -ENOMEM;
 196
 197         data->clusters = devm_kcalloc(&pdev->dev, ARRAY_SIZE(tegra186_clusters),
 198                                       sizeof(*data->clusters), GFP_KERNEL);
 199         if (!data->clusters)
 200                 return -ENOMEM;
 201
 202         data->num_clusters = ARRAY_SIZE(tegra186_clusters);
 203
 204         bpmp = tegra_bpmp_get(&pdev->dev);
 205         if (IS_ERR(bpmp))
 206                 return PTR_ERR(bpmp);
 207
 208         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 209         data->regs = devm_ioremap_resource(&pdev->dev, res);
 210         if (IS_ERR(data->regs)) {
 211                 err = PTR_ERR(data->regs);
 212                 goto put_bpmp;
 213         }
 214
 215         for (i = 0; i < data->num_clusters; i++) {
 216                 struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
 217
 218                 cluster->info = &tegra186_clusters[i];
 219                 cluster->table = init_vhint_table(
 220                         pdev, bpmp, cluster->info->bpmp_cluster_id);
 221                 if (IS_ERR(cluster->table)) {
 222                         err = PTR_ERR(cluster->table);
 223                         goto put_bpmp;
 224                 }
 225         }
 226
 227         tegra_bpmp_put(bpmp);
 228
 229         tegra186_cpufreq_driver.driver_data = data;
 230
 231         err = cpufreq_register_driver(&tegra186_cpufreq_driver);
 232         if (err)
 233                 return err;
 234
 235         return 0;
 236
 237 put_bpmp:
 238         tegra_bpmp_put(bpmp);
 239
 240         return err;
 241 }
 242
 243 static int tegra186_cpufreq_remove(struct platform_device *pdev)
 244 {
 245         cpufreq_unregister_driver(&tegra186_cpufreq_driver);
 246
 247         return 0;
 248 }
 249
 250 static const struct of_device_id tegra186_cpufreq_of_match[] = {
 251         { .compatible = "nvidia,tegra186-ccplex-cluster", },
 252         { }
 253 };
 254 MODULE_DEVICE_TABLE(of, tegra186_cpufreq_of_match);
 255
 256 static struct platform_driver tegra186_cpufreq_platform_driver = {
 257         .driver = {
 258                 .name = "tegra186-cpufreq",
 259                 .of_match_table = tegra186_cpufreq_of_match,
 260         },
 261         .probe = tegra186_cpufreq_probe,
 262         .remove = tegra186_cpufreq_remove,
 263 };
 264 module_platform_driver(tegra186_cpufreq_platform_driver);
 265
 266 MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
 267 MODULE_DESCRIPTION("NVIDIA Tegra186 cpufreq driver");
 268 MODULE_LICENSE("GPL v2");