drivers/devfreq/event/rockchip-dfi.c

   1 /*
   2  * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
   3  * Author: Lin Huang <hl@rock-chips.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  */
  14
  15 #include <linux/clk.h>
  16 #include <linux/devfreq-event.h>
  17 #include <linux/kernel.h>
  18 #include <linux/err.h>
  19 #include <linux/init.h>
  20 #include <linux/io.h>
  21 #include <linux/mfd/syscon.h>
  22 #include <linux/module.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/regmap.h>
  25 #include <linux/slab.h>
  26 #include <linux/list.h>
  27 #include <linux/of.h>
  28
  29 #define RK3399_DMC_NUM_CH       2
  30
  31 /* DDRMON_CTRL */
  32 #define DDRMON_CTRL     0x04
  33 #define CLR_DDRMON_CTRL (0x1f0000 << 0)
  34 #define LPDDR4_EN       (0x10001 << 4)
  35 #define HARDWARE_EN     (0x10001 << 3)
  36 #define LPDDR3_EN       (0x10001 << 2)
  37 #define SOFTWARE_EN     (0x10001 << 1)
  38 #define SOFTWARE_DIS    (0x10000 << 1)
  39 #define TIME_CNT_EN     (0x10001 << 0)
  40
  41 #define DDRMON_CH0_COUNT_NUM            0x28
  42 #define DDRMON_CH0_DFI_ACCESS_NUM       0x2c
  43 #define DDRMON_CH1_COUNT_NUM            0x3c
  44 #define DDRMON_CH1_DFI_ACCESS_NUM       0x40
  45
  46 /* pmu grf */
  47 #define PMUGRF_OS_REG2  0x308
  48 #define DDRTYPE_SHIFT   13
  49 #define DDRTYPE_MASK    7
  50
  51 enum {
  52         DDR3 = 3,
  53         LPDDR3 = 6,
  54         LPDDR4 = 7,
  55         UNUSED = 0xFF
  56 };
  57
  58 struct dmc_usage {
  59         u32 access;
  60         u32 total;
  61 };
  62
  63 /*
  64  * The dfi controller can monitor DDR load. It has an upper and lower threshold
  65  * for the operating points. Whenever the usage leaves these bounds an event is
  66  * generated to indicate the DDR frequency should be changed.
  67  */
  68 struct rockchip_dfi {
  69         struct devfreq_event_dev *edev;
  70         struct devfreq_event_desc *desc;
  71         struct dmc_usage ch_usage[RK3399_DMC_NUM_CH];
  72         struct device *dev;
  73         void __iomem *regs;
  74         struct regmap *regmap_pmu;
  75         struct clk *clk;
  76 };
  77
  78 static void rockchip_dfi_start_hardware_counter(struct devfreq_event_dev *edev)
  79 {
  80         struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
  81         void __iomem *dfi_regs = info->regs;
  82         u32 val;
  83         u32 ddr_type;
  84
  85         /* get ddr type */
  86         regmap_read(info->regmap_pmu, PMUGRF_OS_REG2, &val);
  87         ddr_type = (val >> DDRTYPE_SHIFT) & DDRTYPE_MASK;
  88
  89         /* clear DDRMON_CTRL setting */
  90         writel_relaxed(CLR_DDRMON_CTRL, dfi_regs + DDRMON_CTRL);
  91
  92         /* set ddr type to dfi */
  93         if (ddr_type == LPDDR3)
  94                 writel_relaxed(LPDDR3_EN, dfi_regs + DDRMON_CTRL);
  95         else if (ddr_type == LPDDR4)
  96                 writel_relaxed(LPDDR4_EN, dfi_regs + DDRMON_CTRL);
  97
  98         /* enable count, use software mode */
  99         writel_relaxed(SOFTWARE_EN, dfi_regs + DDRMON_CTRL);
 100 }
 101
 102 static void rockchip_dfi_stop_hardware_counter(struct devfreq_event_dev *edev)
 103 {
 104         struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
 105         void __iomem *dfi_regs = info->regs;
 106
 107         writel_relaxed(SOFTWARE_DIS, dfi_regs + DDRMON_CTRL);
 108 }
 109
 110 static int rockchip_dfi_get_busier_ch(struct devfreq_event_dev *edev)
 111 {
 112         struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
 113         u32 tmp, max = 0;
 114         u32 i, busier_ch = 0;
 115         void __iomem *dfi_regs = info->regs;
 116
 117         rockchip_dfi_stop_hardware_counter(edev);
 118
 119         /* Find out which channel is busier */
 120         for (i = 0; i < RK3399_DMC_NUM_CH; i++) {
 121                 info->ch_usage[i].access = readl_relaxed(dfi_regs +
 122                                 DDRMON_CH0_DFI_ACCESS_NUM + i * 20) * 4;
 123                 info->ch_usage[i].total = readl_relaxed(dfi_regs +
 124                                 DDRMON_CH0_COUNT_NUM + i * 20);
 125                 tmp = info->ch_usage[i].access;
 126                 if (tmp > max) {
 127                         busier_ch = i;
 128                         max = tmp;
 129                 }
 130         }
 131         rockchip_dfi_start_hardware_counter(edev);
 132
 133         return busier_ch;
 134 }
 135
 136 static int rockchip_dfi_disable(struct devfreq_event_dev *edev)
 137 {
 138         struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
 139
 140         rockchip_dfi_stop_hardware_counter(edev);
 141         clk_disable_unprepare(info->clk);
 142
 143         return 0;
 144 }
 145
 146 static int rockchip_dfi_enable(struct devfreq_event_dev *edev)
 147 {
 148         struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
 149         int ret;
 150
 151         ret = clk_prepare_enable(info->clk);
 152         if (ret) {
 153                 dev_err(&edev->dev, "failed to enable dfi clk: %d\n", ret);
 154                 return ret;
 155         }
 156
 157         rockchip_dfi_start_hardware_counter(edev);
 158         return 0;
 159 }
 160
 161 static int rockchip_dfi_set_event(struct devfreq_event_dev *edev)
 162 {
 163         return 0;
 164 }
 165
 166 static int rockchip_dfi_get_event(struct devfreq_event_dev *edev,
 167                                   struct devfreq_event_data *edata)
 168 {
 169         struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
 170         int busier_ch;
 171
 172         busier_ch = rockchip_dfi_get_busier_ch(edev);
 173
 174         edata->load_count = info->ch_usage[busier_ch].access;
 175         edata->total_count = info->ch_usage[busier_ch].total;
 176
 177         return 0;
 178 }
 179
 180 static const struct devfreq_event_ops rockchip_dfi_ops = {
 181         .disable = rockchip_dfi_disable,
 182         .enable = rockchip_dfi_enable,
 183         .get_event = rockchip_dfi_get_event,
 184         .set_event = rockchip_dfi_set_event,
 185 };
 186
 187 static const struct of_device_id rockchip_dfi_id_match[] = {
 188         { .compatible = "rockchip,rk3399-dfi" },
 189         { },
 190 };
 191 MODULE_DEVICE_TABLE(of, rockchip_dfi_id_match);
 192
 193 static int rockchip_dfi_probe(struct platform_device *pdev)
 194 {
 195         struct device *dev = &pdev->dev;
 196         struct rockchip_dfi *data;
 197         struct resource *res;
 198         struct devfreq_event_desc *desc;
 199         struct device_node *np = pdev->dev.of_node, *node;
 200
 201         data = devm_kzalloc(dev, sizeof(struct rockchip_dfi), GFP_KERNEL);
 202         if (!data)
 203                 return -ENOMEM;
 204
 205         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 206         data->regs = devm_ioremap_resource(&pdev->dev, res);
 207         if (IS_ERR(data->regs))
 208                 return PTR_ERR(data->regs);
 209
 210         data->clk = devm_clk_get(dev, "pclk_ddr_mon");
 211         if (IS_ERR(data->clk)) {
 212                 dev_err(dev, "Cannot get the clk dmc_clk\n");
 213                 return PTR_ERR(data->clk);
 214         };
 215
 216         /* try to find the optional reference to the pmu syscon */
 217         node = of_parse_phandle(np, "rockchip,pmu", 0);
 218         if (node) {
 219                 data->regmap_pmu = syscon_node_to_regmap(node);
 220                 if (IS_ERR(data->regmap_pmu))
 221                         return PTR_ERR(data->regmap_pmu);
 222         }
 223         data->dev = dev;
 224
 225         desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
 226         if (!desc)
 227                 return -ENOMEM;
 228
 229         desc->ops = &rockchip_dfi_ops;
 230         desc->driver_data = data;
 231         desc->name = np->name;
 232         data->desc = desc;
 233
 234         data->edev = devm_devfreq_event_add_edev(&pdev->dev, desc);
 235         if (IS_ERR(data->edev)) {
 236                 dev_err(&pdev->dev,
 237                         "failed to add devfreq-event device\n");
 238                 return PTR_ERR(data->edev);
 239         }
 240
 241         platform_set_drvdata(pdev, data);
 242
 243         return 0;
 244 }
 245
 246 static struct platform_driver rockchip_dfi_driver = {
 247         .probe  = rockchip_dfi_probe,
 248         .driver = {
 249                 .name   = "rockchip-dfi",
 250                 .of_match_table = rockchip_dfi_id_match,
 251         },
 252 };
 253 module_platform_driver(rockchip_dfi_driver);
 254
 255 MODULE_LICENSE("GPL v2");
 256 MODULE_AUTHOR("Lin Huang <hl@rock-chips.com>");
 257 MODULE_DESCRIPTION("Rockchip DFI driver");