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
rockchip_dfi_start_hardware_counter(struct devfreq_event_dev * edev)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
rockchip_dfi_stop_hardware_counter(struct devfreq_event_dev * edev)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
rockchip_dfi_get_busier_ch(struct devfreq_event_dev * edev)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
rockchip_dfi_disable(struct devfreq_event_dev * edev)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
rockchip_dfi_enable(struct devfreq_event_dev * edev)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
rockchip_dfi_set_event(struct devfreq_event_dev * edev)144 static int rockchip_dfi_set_event(struct devfreq_event_dev *edev)
145 {
146 return 0;
147 }
148
rockchip_dfi_get_event(struct devfreq_event_dev * edev,struct devfreq_event_data * edata)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
rockchip_dfi_probe(struct platform_device * pdev)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 return dev_err_probe(dev, PTR_ERR(data->clk),
194 "Cannot get the clk pclk_ddr_mon\n");
195
196 /* try to find the optional reference to the pmu syscon */
197 node = of_parse_phandle(np, "rockchip,pmu", 0);
198 if (node) {
199 data->regmap_pmu = syscon_node_to_regmap(node);
200 of_node_put(node);
201 if (IS_ERR(data->regmap_pmu))
202 return PTR_ERR(data->regmap_pmu);
203 }
204 data->dev = dev;
205
206 desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
207 if (!desc)
208 return -ENOMEM;
209
210 desc->ops = &rockchip_dfi_ops;
211 desc->driver_data = data;
212 desc->name = np->name;
213 data->desc = desc;
214
215 data->edev = devm_devfreq_event_add_edev(&pdev->dev, desc);
216 if (IS_ERR(data->edev)) {
217 dev_err(&pdev->dev,
218 "failed to add devfreq-event device\n");
219 return PTR_ERR(data->edev);
220 }
221
222 platform_set_drvdata(pdev, data);
223
224 return 0;
225 }
226
227 static struct platform_driver rockchip_dfi_driver = {
228 .probe = rockchip_dfi_probe,
229 .driver = {
230 .name = "rockchip-dfi",
231 .of_match_table = rockchip_dfi_id_match,
232 },
233 };
234 module_platform_driver(rockchip_dfi_driver);
235
236 MODULE_LICENSE("GPL v2");
237 MODULE_AUTHOR("Lin Huang <hl@rock-chips.com>");
238 MODULE_DESCRIPTION("Rockchip DFI driver");
239
