drivers/devfreq/event/exynos-nocp.c

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