summaryrefslogtreecommitdiffstats
path: root/drivers/devfreq/event/rockchip-dfi.c
blob: 4dafdf23197b921aade44fb0db3373b00f17f5c2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
 * Author: Lin Huang <hl@rock-chips.com>
 */

#include <linux/clk.h>
#include <linux/devfreq-event.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/of.h>

#include <soc/rockchip/rk3399_grf.h>

#define RK3399_DMC_NUM_CH	2

/* DDRMON_CTRL */
#define DDRMON_CTRL	0x04
#define CLR_DDRMON_CTRL	(0x1f0000 << 0)
#define LPDDR4_EN	(0x10001 << 4)
#define HARDWARE_EN	(0x10001 << 3)
#define LPDDR3_EN	(0x10001 << 2)
#define SOFTWARE_EN	(0x10001 << 1)
#define SOFTWARE_DIS	(0x10000 << 1)
#define TIME_CNT_EN	(0x10001 << 0)

#define DDRMON_CH0_COUNT_NUM		0x28
#define DDRMON_CH0_DFI_ACCESS_NUM	0x2c
#define DDRMON_CH1_COUNT_NUM		0x3c
#define DDRMON_CH1_DFI_ACCESS_NUM	0x40

struct dmc_usage {
	u32 access;
	u32 total;
};

/*
 * The dfi controller can monitor DDR load. It has an upper and lower threshold
 * for the operating points. Whenever the usage leaves these bounds an event is
 * generated to indicate the DDR frequency should be changed.
 */
struct rockchip_dfi {
	struct devfreq_event_dev *edev;
	struct devfreq_event_desc *desc;
	struct dmc_usage ch_usage[RK3399_DMC_NUM_CH];
	struct device *dev;
	void __iomem *regs;
	struct regmap *regmap_pmu;
	struct clk *clk;
};

static void rockchip_dfi_start_hardware_counter(struct devfreq_event_dev *edev)
{
	struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
	void __iomem *dfi_regs = info->regs;
	u32 val;
	u32 ddr_type;

	/* get ddr type */
	regmap_read(info->regmap_pmu, RK3399_PMUGRF_OS_REG2, &val);
	ddr_type = (val >> RK3399_PMUGRF_DDRTYPE_SHIFT) &
		    RK3399_PMUGRF_DDRTYPE_MASK;

	/* clear DDRMON_CTRL setting */
	writel_relaxed(CLR_DDRMON_CTRL, dfi_regs + DDRMON_CTRL);

	/* set ddr type to dfi */
	if (ddr_type == RK3399_PMUGRF_DDRTYPE_LPDDR3)
		writel_relaxed(LPDDR3_EN, dfi_regs + DDRMON_CTRL);
	else if (ddr_type == RK3399_PMUGRF_DDRTYPE_LPDDR4)
		writel_relaxed(LPDDR4_EN, dfi_regs + DDRMON_CTRL);

	/* enable count, use software mode */
	writel_relaxed(SOFTWARE_EN, dfi_regs + DDRMON_CTRL);
}

static void rockchip_dfi_stop_hardware_counter(struct devfreq_event_dev *edev)
{
	struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
	void __iomem *dfi_regs = info->regs;

	writel_relaxed(SOFTWARE_DIS, dfi_regs + DDRMON_CTRL);
}

static int rockchip_dfi_get_busier_ch(struct devfreq_event_dev *edev)
{
	struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
	u32 tmp, max = 0;
	u32 i, busier_ch = 0;
	void __iomem *dfi_regs = info->regs;

	rockchip_dfi_stop_hardware_counter(edev);

	/* Find out which channel is busier */
	for (i = 0; i < RK3399_DMC_NUM_CH; i++) {
		info->ch_usage[i].access = readl_relaxed(dfi_regs +
				DDRMON_CH0_DFI_ACCESS_NUM + i * 20) * 4;
		info->ch_usage[i].total = readl_relaxed(dfi_regs +
				DDRMON_CH0_COUNT_NUM + i * 20);
		tmp = info->ch_usage[i].access;
		if (tmp > max) {
			busier_ch = i;
			max = tmp;
		}
	}
	rockchip_dfi_start_hardware_counter(edev);

	return busier_ch;
}

static int rockchip_dfi_disable(struct devfreq_event_dev *edev)
{
	struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);

	rockchip_dfi_stop_hardware_counter(edev);
	clk_disable_unprepare(info->clk);

	return 0;
}

static int rockchip_dfi_enable(struct devfreq_event_dev *edev)
{
	struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
	int ret;

	ret = clk_prepare_enable(info->clk);
	if (ret) {
		dev_err(&edev->dev, "failed to enable dfi clk: %d\n", ret);
		return ret;
	}

	rockchip_dfi_start_hardware_counter(edev);
	return 0;
}

static int rockchip_dfi_set_event(struct devfreq_event_dev *edev)
{
	return 0;
}

static int rockchip_dfi_get_event(struct devfreq_event_dev *edev,
				  struct devfreq_event_data *edata)
{
	struct rockchip_dfi *info = devfreq_event_get_drvdata(edev);
	int busier_ch;

	busier_ch = rockchip_dfi_get_busier_ch(edev);

	edata->load_count = info->ch_usage[busier_ch].access;
	edata->total_count = info->ch_usage[busier_ch].total;

	return 0;
}

static const struct devfreq_event_ops rockchip_dfi_ops = {
	.disable = rockchip_dfi_disable,
	.enable = rockchip_dfi_enable,
	.get_event = rockchip_dfi_get_event,
	.set_event = rockchip_dfi_set_event,
};

static const struct of_device_id rockchip_dfi_id_match[] = {
	{ .compatible = "rockchip,rk3399-dfi" },
	{ },
};
MODULE_DEVICE_TABLE(of, rockchip_dfi_id_match);

static int rockchip_dfi_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct rockchip_dfi *data;
	struct devfreq_event_desc *desc;
	struct device_node *np = pdev->dev.of_node, *node;

	data = devm_kzalloc(dev, sizeof(struct rockchip_dfi), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->regs = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(data->regs))
		return PTR_ERR(data->regs);

	data->clk = devm_clk_get(dev, "pclk_ddr_mon");
	if (IS_ERR(data->clk)) {
		dev_err(dev, "Cannot get the clk dmc_clk\n");
		return PTR_ERR(data->clk);
	}

	node = of_parse_phandle(np, "rockchip,pmu", 0);
	if (!node)
		return dev_err_probe(&pdev->dev, -ENODEV, "Can't find pmu_grf registers\n");

	data->regmap_pmu = syscon_node_to_regmap(node);
	of_node_put(node);
	if (IS_ERR(data->regmap_pmu))
		return PTR_ERR(data->regmap_pmu);

	data->dev = dev;

	desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
	if (!desc)
		return -ENOMEM;

	desc->ops = &rockchip_dfi_ops;
	desc->driver_data = data;
	desc->name = np->name;
	data->desc = desc;

	data->edev = devm_devfreq_event_add_edev(&pdev->dev, desc);
	if (IS_ERR(data->edev)) {
		dev_err(&pdev->dev,
			"failed to add devfreq-event device\n");
		return PTR_ERR(data->edev);
	}

	platform_set_drvdata(pdev, data);

	return 0;
}

static struct platform_driver rockchip_dfi_driver = {
	.probe	= rockchip_dfi_probe,
	.driver = {
		.name	= "rockchip-dfi",
		.of_match_table = rockchip_dfi_id_match,
	},
};
module_platform_driver(rockchip_dfi_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Lin Huang <hl@rock-chips.com>");
MODULE_DESCRIPTION("Rockchip DFI driver");