drivers/devfreq/event/exynos-nocp.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * exynos-nocp.c - EXYNOS NoC (Network On Chip) Probe support
   4  *
   5  * Copyright (c) 2016 Samsung Electronics Co., Ltd.
   6  * Author : Chanwoo Choi <cw00.choi@samsung.com>
   7  */
   8
   9 #include <linux/clk.h>
  10 #include <linux/module.h>
  11 #include <linux/devfreq-event.h>
  12 #include <linux/kernel.h>
  13 #include <linux/of_address.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/regmap.h>
  16
  17 #include "exynos-nocp.h"
  18
  19 struct exynos_nocp {
  20         struct devfreq_event_dev *edev;
  21         struct devfreq_event_desc desc;
  22
  23         struct device *dev;
  24
  25         struct regmap *regmap;
  26         struct clk *clk;
  27 };
  28
  29 /*
  30  * The devfreq-event ops structure for nocp probe.
  31  */
  32 static int exynos_nocp_set_event(struct devfreq_event_dev *edev)
  33 {
  34         struct exynos_nocp *nocp = devfreq_event_get_drvdata(edev);
  35         int ret;
  36
  37         /* Disable NoC probe */
  38         ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
  39                                 NOCP_MAIN_CTL_STATEN_MASK, 0);
  40         if (ret < 0) {
  41                 dev_err(nocp->dev, "failed to disable the NoC probe device\n");
  42                 return ret;
  43         }
  44
  45         /* Set a statistics dump period to 0 */
  46         ret = regmap_write(nocp->regmap, NOCP_STAT_PERIOD, 0x0);
  47         if (ret < 0)
  48                 goto out;
  49
  50         /* Set the IntEvent fields of *_SRC */
  51         ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_0_SRC,
  52                                 NOCP_CNT_SRC_INTEVENT_MASK,
  53                                 NOCP_CNT_SRC_INTEVENT_BYTE_MASK);
  54         if (ret < 0)
  55                 goto out;
  56
  57         ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_1_SRC,
  58                                 NOCP_CNT_SRC_INTEVENT_MASK,
  59                                 NOCP_CNT_SRC_INTEVENT_CHAIN_MASK);
  60         if (ret < 0)
  61                 goto out;
  62
  63         ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_2_SRC,
  64                                 NOCP_CNT_SRC_INTEVENT_MASK,
  65                                 NOCP_CNT_SRC_INTEVENT_CYCLE_MASK);
  66         if (ret < 0)
  67                 goto out;
  68
  69         ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_3_SRC,
  70                                 NOCP_CNT_SRC_INTEVENT_MASK,
  71                                 NOCP_CNT_SRC_INTEVENT_CHAIN_MASK);
  72         if (ret < 0)
  73                 goto out;
  74
  75
  76         /* Set an alarm with a max/min value of 0 to generate StatALARM */
  77         ret = regmap_write(nocp->regmap, NOCP_STAT_ALARM_MIN, 0x0);
  78         if (ret < 0)
  79                 goto out;
  80
  81         ret = regmap_write(nocp->regmap, NOCP_STAT_ALARM_MAX, 0x0);
  82         if (ret < 0)
  83                 goto out;
  84
  85         /* Set AlarmMode */
  86         ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_0_ALARM_MODE,
  87                                 NOCP_CNT_ALARM_MODE_MASK,
  88                                 NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
  89         if (ret < 0)
  90                 goto out;
  91
  92         ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_1_ALARM_MODE,
  93                                 NOCP_CNT_ALARM_MODE_MASK,
  94                                 NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
  95         if (ret < 0)
  96                 goto out;
  97
  98         ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_2_ALARM_MODE,
  99                                 NOCP_CNT_ALARM_MODE_MASK,
 100                                 NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
 101         if (ret < 0)
 102                 goto out;
 103
 104         ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_3_ALARM_MODE,
 105                                 NOCP_CNT_ALARM_MODE_MASK,
 106                                 NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
 107         if (ret < 0)
 108                 goto out;
 109
 110         /* Enable the measurements by setting AlarmEn and StatEn */
 111         ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
 112                         NOCP_MAIN_CTL_STATEN_MASK | NOCP_MAIN_CTL_ALARMEN_MASK,
 113                         NOCP_MAIN_CTL_STATEN_MASK | NOCP_MAIN_CTL_ALARMEN_MASK);
 114         if (ret < 0)
 115                 goto out;
 116
 117         /* Set GlobalEN */
 118         ret = regmap_update_bits(nocp->regmap, NOCP_CFG_CTL,
 119                                 NOCP_CFG_CTL_GLOBALEN_MASK,
 120                                 NOCP_CFG_CTL_GLOBALEN_MASK);
 121         if (ret < 0)
 122                 goto out;
 123
 124         /* Enable NoC probe */
 125         ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
 126                                 NOCP_MAIN_CTL_STATEN_MASK,
 127                                 NOCP_MAIN_CTL_STATEN_MASK);
 128         if (ret < 0)
 129                 goto out;
 130
 131         return 0;
 132
 133 out:
 134         /* Reset NoC probe */
 135         if (regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
 136                                 NOCP_MAIN_CTL_STATEN_MASK, 0)) {
 137                 dev_err(nocp->dev, "Failed to reset NoC probe device\n");
 138         }
 139
 140         return ret;
 141 }
 142
 143 static int exynos_nocp_get_event(struct devfreq_event_dev *edev,
 144                                 struct devfreq_event_data *edata)
 145 {
 146         struct exynos_nocp *nocp = devfreq_event_get_drvdata(edev);
 147         unsigned int counter[4];
 148         int ret;
 149
 150         /* Read cycle count */
 151         ret = regmap_read(nocp->regmap, NOCP_COUNTERS_0_VAL, &counter[0]);
 152         if (ret < 0)
 153                 goto out;
 154
 155         ret = regmap_read(nocp->regmap, NOCP_COUNTERS_1_VAL, &counter[1]);
 156         if (ret < 0)
 157                 goto out;
 158
 159         ret = regmap_read(nocp->regmap, NOCP_COUNTERS_2_VAL, &counter[2]);
 160         if (ret < 0)
 161                 goto out;
 162
 163         ret = regmap_read(nocp->regmap, NOCP_COUNTERS_3_VAL, &counter[3]);
 164         if (ret < 0)
 165                 goto out;
 166
 167         edata->load_count = ((counter[1] << 16) | counter[0]);
 168         edata->total_count = ((counter[3] << 16) | counter[2]);
 169
 170         dev_dbg(&edev->dev, "%s (event: %ld/%ld)\n", edev->desc->name,
 171                                         edata->load_count, edata->total_count);
 172
 173         return 0;
 174
 175 out:
 176         dev_err(nocp->dev, "Failed to read the counter of NoC probe device\n");
 177
 178         return ret;
 179 }
 180
 181 static const struct devfreq_event_ops exynos_nocp_ops = {
 182         .set_event = exynos_nocp_set_event,
 183         .get_event = exynos_nocp_get_event,
 184 };
 185
 186 static const struct of_device_id exynos_nocp_id_match[] = {
 187         { .compatible = "samsung,exynos5420-nocp", },
 188         { /* sentinel */ },
 189 };
 190 MODULE_DEVICE_TABLE(of, exynos_nocp_id_match);
 191
 192 static struct regmap_config exynos_nocp_regmap_config = {
 193         .reg_bits = 32,
 194         .val_bits = 32,
 195         .reg_stride = 4,
 196         .max_register = NOCP_COUNTERS_3_VAL,
 197 };
 198
 199 static int exynos_nocp_parse_dt(struct platform_device *pdev,
 200                                 struct exynos_nocp *nocp)
 201 {
 202         struct device *dev = nocp->dev;
 203         struct device_node *np = dev->of_node;
 204         struct resource *res;
 205         void __iomem *base;
 206
 207         if (!np) {
 208                 dev_err(dev, "failed to find devicetree node\n");
 209                 return -EINVAL;
 210         }
 211
 212         nocp->clk = devm_clk_get(dev, "nocp");
 213         if (IS_ERR(nocp->clk))
 214                 nocp->clk = NULL;
 215
 216         /* Maps the memory mapped IO to control nocp register */
 217         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 218         base = devm_ioremap_resource(dev, res);
 219         if (IS_ERR(base))
 220                 return PTR_ERR(base);
 221
 222         exynos_nocp_regmap_config.max_register = resource_size(res) - 4;
 223
 224         nocp->regmap = devm_regmap_init_mmio(dev, base,
 225                                         &exynos_nocp_regmap_config);
 226         if (IS_ERR(nocp->regmap)) {
 227                 dev_err(dev, "failed to initialize regmap\n");
 228                 return PTR_ERR(nocp->regmap);
 229         }
 230
 231         return 0;
 232 }
 233
 234 static int exynos_nocp_probe(struct platform_device *pdev)
 235 {
 236         struct device *dev = &pdev->dev;
 237         struct device_node *np = dev->of_node;
 238         struct exynos_nocp *nocp;
 239         int ret;
 240
 241         nocp = devm_kzalloc(&pdev->dev, sizeof(*nocp), GFP_KERNEL);
 242         if (!nocp)
 243                 return -ENOMEM;
 244
 245         nocp->dev = &pdev->dev;
 246
 247         /* Parse dt data to get resource */
 248         ret = exynos_nocp_parse_dt(pdev, nocp);
 249         if (ret < 0) {
 250                 dev_err(&pdev->dev,
 251                         "failed to parse devicetree for resource\n");
 252                 return ret;
 253         }
 254
 255         /* Add devfreq-event device to measure the bandwidth of NoC */
 256         nocp->desc.ops = &exynos_nocp_ops;
 257         nocp->desc.driver_data = nocp;
 258         nocp->desc.name = np->full_name;
 259         nocp->edev = devm_devfreq_event_add_edev(&pdev->dev, &nocp->desc);
 260         if (IS_ERR(nocp->edev)) {
 261                 dev_err(&pdev->dev,
 262                         "failed to add devfreq-event device\n");
 263                 return PTR_ERR(nocp->edev);
 264         }
 265         platform_set_drvdata(pdev, nocp);
 266
 267         ret = clk_prepare_enable(nocp->clk);
 268         if (ret) {
 269                 dev_err(&pdev->dev, "failed to prepare ppmu clock\n");
 270                 return ret;
 271         }
 272
 273         pr_info("exynos-nocp: new NoC Probe device registered: %s\n",
 274                         dev_name(dev));
 275
 276         return 0;
 277 }
 278
 279 static int exynos_nocp_remove(struct platform_device *pdev)
 280 {
 281         struct exynos_nocp *nocp = platform_get_drvdata(pdev);
 282
 283         clk_disable_unprepare(nocp->clk);
 284
 285         return 0;
 286 }
 287
 288 static struct platform_driver exynos_nocp_driver = {
 289         .probe  = exynos_nocp_probe,
 290         .remove = exynos_nocp_remove,
 291         .driver = {
 292                 .name   = "exynos-nocp",
 293                 .of_match_table = exynos_nocp_id_match,
 294         },
 295 };
 296 module_platform_driver(exynos_nocp_driver);
 297
 298 MODULE_DESCRIPTION("Exynos NoC (Network on Chip) Probe driver");
 299 MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
 300 MODULE_LICENSE("GPL");