2 * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
3 * Author: Lin Huang <hl@rock-chips.com>
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.
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
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>
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>
29 #define RK3399_DMC_NUM_CH 2
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)
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
47 #define PMUGRF_OS_REG2 0x308
48 #define DDRTYPE_SHIFT 13
49 #define DDRTYPE_MASK 7
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.
69 struct devfreq_event_dev *edev;
70 struct devfreq_event_desc *desc;
71 struct dmc_usage ch_usage[RK3399_DMC_NUM_CH];
74 struct regmap *regmap_pmu;
78 static void rockchip_dfi_start_hardware_counter(struct devfreq_event_dev *edev)
80 struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
81 void __iomem *dfi_regs = info->regs;
86 regmap_read(info->regmap_pmu, PMUGRF_OS_REG2, &val);
87 ddr_type = (val >> DDRTYPE_SHIFT) & DDRTYPE_MASK;
89 /* clear DDRMON_CTRL setting */
90 writel_relaxed(CLR_DDRMON_CTRL, dfi_regs + DDRMON_CTRL);
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);
98 /* enable count, use software mode */
99 writel_relaxed(SOFTWARE_EN, dfi_regs + DDRMON_CTRL);
102 static void rockchip_dfi_stop_hardware_counter(struct devfreq_event_dev *edev)
104 struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
105 void __iomem *dfi_regs = info->regs;
107 writel_relaxed(SOFTWARE_DIS, dfi_regs + DDRMON_CTRL);
110 static int rockchip_dfi_get_busier_ch(struct devfreq_event_dev *edev)
112 struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
114 u32 i, busier_ch = 0;
115 void __iomem *dfi_regs = info->regs;
117 rockchip_dfi_stop_hardware_counter(edev);
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;
131 rockchip_dfi_start_hardware_counter(edev);
136 static int rockchip_dfi_disable(struct devfreq_event_dev *edev)
138 struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
140 rockchip_dfi_stop_hardware_counter(edev);
141 clk_disable_unprepare(info->clk);
146 static int rockchip_dfi_enable(struct devfreq_event_dev *edev)
148 struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
151 ret = clk_prepare_enable(info->clk);
153 dev_err(&edev->dev, "failed to enable dfi clk: %d\n", ret);
157 rockchip_dfi_start_hardware_counter(edev);
161 static int rockchip_dfi_set_event(struct devfreq_event_dev *edev)
166 static int rockchip_dfi_get_event(struct devfreq_event_dev *edev,
167 struct devfreq_event_data *edata)
169 struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
173 local_irq_save(flags);
174 busier_ch = rockchip_dfi_get_busier_ch(edev);
175 local_irq_restore(flags);
177 edata->load_count = info->ch_usage[busier_ch].access;
178 edata->total_count = info->ch_usage[busier_ch].total;
183 static const struct devfreq_event_ops rockchip_dfi_ops = {
184 .disable = rockchip_dfi_disable,
185 .enable = rockchip_dfi_enable,
186 .get_event = rockchip_dfi_get_event,
187 .set_event = rockchip_dfi_set_event,
190 static const struct of_device_id rockchip_dfi_id_match[] = {
191 { .compatible = "rockchip,rk3399-dfi" },
195 static int rockchip_dfi_probe(struct platform_device *pdev)
197 struct device *dev = &pdev->dev;
198 struct rockchip_dfi *data;
199 struct resource *res;
200 struct devfreq_event_desc *desc;
201 struct device_node *np = pdev->dev.of_node, *node;
203 data = devm_kzalloc(dev, sizeof(struct rockchip_dfi), GFP_KERNEL);
207 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
208 data->regs = devm_ioremap_resource(&pdev->dev, res);
209 if (IS_ERR(data->regs))
210 return PTR_ERR(data->regs);
212 data->clk = devm_clk_get(dev, "pclk_ddr_mon");
213 if (IS_ERR(data->clk)) {
214 dev_err(dev, "Cannot get the clk dmc_clk\n");
215 return PTR_ERR(data->clk);
218 /* try to find the optional reference to the pmu syscon */
219 node = of_parse_phandle(np, "rockchip,pmu", 0);
221 data->regmap_pmu = syscon_node_to_regmap(node);
222 if (IS_ERR(data->regmap_pmu))
223 return PTR_ERR(data->regmap_pmu);
227 desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
231 desc->ops = &rockchip_dfi_ops;
232 desc->driver_data = data;
233 desc->name = np->name;
236 data->edev = devm_devfreq_event_add_edev(&pdev->dev, desc);
237 if (IS_ERR(data->edev)) {
239 "failed to add devfreq-event device\n");
240 return PTR_ERR(data->edev);
243 platform_set_drvdata(pdev, data);
248 static struct platform_driver rockchip_dfi_driver = {
249 .probe = rockchip_dfi_probe,
251 .name = "rockchip-dfi",
252 .of_match_table = rockchip_dfi_id_match,
255 module_platform_driver(rockchip_dfi_driver);
257 MODULE_LICENSE("GPL v2");
258 MODULE_AUTHOR("Lin Huang <hl@rock-chips.com>");
259 MODULE_DESCRIPTION("Rockchip DFI driver");