drivers/devfreq/event/rockchip-dfi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
   4  * Author: Lin Huang <hl@rock-chips.com>
   5  */
   6
   7 #include <linux/clk.h>
   8 #include <linux/devfreq-event.h>
   9 #include <linux/kernel.h>
  10 #include <linux/err.h>
  11 #include <linux/init.h>
  12 #include <linux/io.h>
  13 #include <linux/mfd/syscon.h>
  14 #include <linux/module.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/regmap.h>
  17 #include <linux/slab.h>
  18 #include <linux/list.h>
  19 #include <linux/of.h>
  20
  21 #include <soc/rockchip/rk3399_grf.h>
  22
  23 #define RK3399_DMC_NUM_CH       2
  24
  25 /* DDRMON_CTRL */
  26 #define DDRMON_CTRL     0x04
  27 #define CLR_DDRMON_CTRL (0x1f0000 << 0)
  28 #define LPDDR4_EN       (0x10001 << 4)
  29 #define HARDWARE_EN     (0x10001 << 3)
  30 #define LPDDR3_EN       (0x10001 << 2)
  31 #define SOFTWARE_EN     (0x10001 << 1)
  32 #define SOFTWARE_DIS    (0x10000 << 1)
  33 #define TIME_CNT_EN     (0x10001 << 0)
  34
  35 #define DDRMON_CH0_COUNT_NUM            0x28
  36 #define DDRMON_CH0_DFI_ACCESS_NUM       0x2c
  37 #define DDRMON_CH1_COUNT_NUM            0x3c
  38 #define DDRMON_CH1_DFI_ACCESS_NUM       0x40
  39
  40 struct dmc_usage {
  41         u32 access;
  42         u32 total;
  43 };
  44
  45 /*
  46  * The dfi controller can monitor DDR load. It has an upper and lower threshold
  47  * for the operating points. Whenever the usage leaves these bounds an event is
  48  * generated to indicate the DDR frequency should be changed.
  49  */
  50 struct rockchip_dfi {
  51         struct devfreq_event_dev *edev;
  52         struct devfreq_event_desc *desc;
  53         struct dmc_usage ch_usage[RK3399_DMC_NUM_CH];
  54         struct device *dev;
  55         void __iomem *regs;
  56         struct regmap *regmap_pmu;
  57         struct clk *clk;
  58 };
  59
  60 static void rockchip_dfi_start_hardware_counter(struct devfreq_event_dev *edev)
  61 {
  62         struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
  63         void __iomem *dfi_regs = info->regs;
  64         u32 val;
  65         u32 ddr_type;
  66
  67         /* get ddr type */
  68         regmap_read(info->regmap_pmu, RK3399_PMUGRF_OS_REG2, &val);
  69         ddr_type = (val >> RK3399_PMUGRF_DDRTYPE_SHIFT) &
  70                     RK3399_PMUGRF_DDRTYPE_MASK;
  71
  72         /* clear DDRMON_CTRL setting */
  73         writel_relaxed(CLR_DDRMON_CTRL, dfi_regs + DDRMON_CTRL);
  74
  75         /* set ddr type to dfi */
  76         if (ddr_type == RK3399_PMUGRF_DDRTYPE_LPDDR3)
  77                 writel_relaxed(LPDDR3_EN, dfi_regs + DDRMON_CTRL);
  78         else if (ddr_type == RK3399_PMUGRF_DDRTYPE_LPDDR4)
  79                 writel_relaxed(LPDDR4_EN, dfi_regs + DDRMON_CTRL);
  80
  81         /* enable count, use software mode */
  82         writel_relaxed(SOFTWARE_EN, dfi_regs + DDRMON_CTRL);
  83 }
  84
  85 static void rockchip_dfi_stop_hardware_counter(struct devfreq_event_dev *edev)
  86 {
  87         struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
  88         void __iomem *dfi_regs = info->regs;
  89
  90         writel_relaxed(SOFTWARE_DIS, dfi_regs + DDRMON_CTRL);
  91 }
  92
  93 static int rockchip_dfi_get_busier_ch(struct devfreq_event_dev *edev)
  94 {
  95         struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
  96         u32 tmp, max = 0;
  97         u32 i, busier_ch = 0;
  98         void __iomem *dfi_regs = info->regs;
  99
 100         rockchip_dfi_stop_hardware_counter(edev);
 101
 102         /* Find out which channel is busier */
 103         for (i = 0; i < RK3399_DMC_NUM_CH; i++) {
 104                 info->ch_usage[i].access = readl_relaxed(dfi_regs +
 105                                 DDRMON_CH0_DFI_ACCESS_NUM + i * 20) * 4;
 106                 info->ch_usage[i].total = readl_relaxed(dfi_regs +
 107                                 DDRMON_CH0_COUNT_NUM + i * 20);
 108                 tmp = info->ch_usage[i].access;
 109                 if (tmp > max) {
 110                         busier_ch = i;
 111                         max = tmp;
 112                 }
 113         }
 114         rockchip_dfi_start_hardware_counter(edev);
 115
 116         return busier_ch;
 117 }
 118
 119 static int rockchip_dfi_disable(struct devfreq_event_dev *edev)
 120 {
 121         struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
 122
 123         rockchip_dfi_stop_hardware_counter(edev);
 124         clk_disable_unprepare(info->clk);
 125
 126         return 0;
 127 }
 128
 129 static int rockchip_dfi_enable(struct devfreq_event_dev *edev)
 130 {
 131         struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
 132         int ret;
 133
 134         ret = clk_prepare_enable(info->clk);
 135         if (ret) {
 136                 dev_err(&edev->dev, "failed to enable dfi clk: %d\n", ret);
 137                 return ret;
 138         }
 139
 140         rockchip_dfi_start_hardware_counter(edev);
 141         return 0;
 142 }
 143
 144 static int rockchip_dfi_set_event(struct devfreq_event_dev *edev)
 145 {
 146         return 0;
 147 }
 148
 149 static int rockchip_dfi_get_event(struct devfreq_event_dev *edev,
 150                                   struct devfreq_event_data *edata)
 151 {
 152         struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
 153         int busier_ch;
 154
 155         busier_ch = rockchip_dfi_get_busier_ch(edev);
 156
 157         edata->load_count = info->ch_usage[busier_ch].access;
 158         edata->total_count = info->ch_usage[busier_ch].total;
 159
 160         return 0;
 161 }
 162
 163 static const struct devfreq_event_ops rockchip_dfi_ops = {
 164         .disable = rockchip_dfi_disable,
 165         .enable = rockchip_dfi_enable,
 166         .get_event = rockchip_dfi_get_event,
 167         .set_event = rockchip_dfi_set_event,
 168 };
 169
 170 static const struct of_device_id rockchip_dfi_id_match[] = {
 171         { .compatible = "rockchip,rk3399-dfi" },
 172         { },
 173 };
 174 MODULE_DEVICE_TABLE(of, rockchip_dfi_id_match);
 175
 176 static int rockchip_dfi_probe(struct platform_device *pdev)
 177 {
 178         struct device *dev = &pdev->dev;
 179         struct rockchip_dfi *data;
 180         struct devfreq_event_desc *desc;
 181         struct device_node *np = pdev->dev.of_node, *node;
 182
 183         data = devm_kzalloc(dev, sizeof(struct rockchip_dfi), GFP_KERNEL);
 184         if (!data)
 185                 return -ENOMEM;
 186
 187         data->regs = devm_platform_ioremap_resource(pdev, 0);
 188         if (IS_ERR(data->regs))
 189                 return PTR_ERR(data->regs);
 190
 191         data->clk = devm_clk_get(dev, "pclk_ddr_mon");
 192         if (IS_ERR(data->clk)) {
 193                 dev_err(dev, "Cannot get the clk dmc_clk\n");
 194                 return PTR_ERR(data->clk);
 195         }
 196
 197         /* try to find the optional reference to the pmu syscon */
 198         node = of_parse_phandle(np, "rockchip,pmu", 0);
 199         if (node) {
 200                 data->regmap_pmu = syscon_node_to_regmap(node);
 201                 of_node_put(node);
 202                 if (IS_ERR(data->regmap_pmu))
 203                         return PTR_ERR(data->regmap_pmu);
 204         }
 205         data->dev = dev;
 206
 207         desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
 208         if (!desc)
 209                 return -ENOMEM;
 210
 211         desc->ops = &rockchip_dfi_ops;
 212         desc->driver_data = data;
 213         desc->name = np->name;
 214         data->desc = desc;
 215
 216         data->edev = devm_devfreq_event_add_edev(&pdev->dev, desc);
 217         if (IS_ERR(data->edev)) {
 218                 dev_err(&pdev->dev,
 219                         "failed to add devfreq-event device\n");
 220                 return PTR_ERR(data->edev);
 221         }
 222
 223         platform_set_drvdata(pdev, data);
 224
 225         return 0;
 226 }
 227
 228 static struct platform_driver rockchip_dfi_driver = {
 229         .probe  = rockchip_dfi_probe,
 230         .driver = {
 231                 .name   = "rockchip-dfi",
 232                 .of_match_table = rockchip_dfi_id_match,
 233         },
 234 };
 235 module_platform_driver(rockchip_dfi_driver);
 236
 237 MODULE_LICENSE("GPL v2");
 238 MODULE_AUTHOR("Lin Huang <hl@rock-chips.com>");
 239 MODULE_DESCRIPTION("Rockchip DFI driver");