summaryrefslogtreecommitdiff
path: root/drivers/devfreq/imx-bus.c
blob: 49798f542d6809e716604e80b20eddabcb84e14c (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
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2019 NXP
 */

#include <linux/clk.h>
#include <linux/devfreq.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pm_opp.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

struct imx_bus {
	struct devfreq_dev_profile profile;
	struct devfreq *devfreq;
	struct clk *clk;
	struct platform_device *icc_pdev;
};

static int imx_bus_target(struct device *dev,
		unsigned long *freq, u32 flags)
{
	struct dev_pm_opp *new_opp;
	int ret;

	new_opp = devfreq_recommended_opp(dev, freq, flags);
	if (IS_ERR(new_opp)) {
		ret = PTR_ERR(new_opp);
		dev_err(dev, "failed to get recommended opp: %d\n", ret);
		return ret;
	}
	dev_pm_opp_put(new_opp);

	return dev_pm_opp_set_rate(dev, *freq);
}

static int imx_bus_get_cur_freq(struct device *dev, unsigned long *freq)
{
	struct imx_bus *priv = dev_get_drvdata(dev);

	*freq = clk_get_rate(priv->clk);

	return 0;
}

static void imx_bus_exit(struct device *dev)
{
	struct imx_bus *priv = dev_get_drvdata(dev);

	dev_pm_opp_of_remove_table(dev);
	platform_device_unregister(priv->icc_pdev);
}

/* imx_bus_init_icc() - register matching icc provider if required */
static int imx_bus_init_icc(struct device *dev)
{
	struct imx_bus *priv = dev_get_drvdata(dev);
	const char *icc_driver_name;

	if (!of_property_present(dev->of_node, "#interconnect-cells"))
		return 0;
	if (!IS_ENABLED(CONFIG_INTERCONNECT_IMX)) {
		dev_warn(dev, "imx interconnect drivers disabled\n");
		return 0;
	}

	icc_driver_name = of_device_get_match_data(dev);
	if (!icc_driver_name) {
		dev_err(dev, "unknown interconnect driver\n");
		return 0;
	}

	priv->icc_pdev = platform_device_register_data(
			dev, icc_driver_name, -1, NULL, 0);
	if (IS_ERR(priv->icc_pdev)) {
		dev_err(dev, "failed to register icc provider %s: %ld\n",
				icc_driver_name, PTR_ERR(priv->icc_pdev));
		return PTR_ERR(priv->icc_pdev);
	}

	return 0;
}

static int imx_bus_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct imx_bus *priv;
	const char *gov = DEVFREQ_GOV_USERSPACE;
	int ret;

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

	/*
	 * Fetch the clock to adjust but don't explicitly enable.
	 *
	 * For imx bus clock clk_set_rate is safe no matter if the clock is on
	 * or off and some peripheral side-buses might be off unless enabled by
	 * drivers for devices on those specific buses.
	 *
	 * Rate adjustment on a disabled bus clock just takes effect later.
	 */
	priv->clk = devm_clk_get(dev, NULL);
	if (IS_ERR(priv->clk)) {
		ret = PTR_ERR(priv->clk);
		dev_err(dev, "failed to fetch clk: %d\n", ret);
		return ret;
	}
	platform_set_drvdata(pdev, priv);

	ret = dev_pm_opp_of_add_table(dev);
	if (ret < 0) {
		dev_err(dev, "failed to get OPP table\n");
		return ret;
	}

	priv->profile.target = imx_bus_target;
	priv->profile.exit = imx_bus_exit;
	priv->profile.get_cur_freq = imx_bus_get_cur_freq;
	priv->profile.initial_freq = clk_get_rate(priv->clk);

	priv->devfreq = devm_devfreq_add_device(dev, &priv->profile,
						gov, NULL);
	if (IS_ERR(priv->devfreq)) {
		ret = PTR_ERR(priv->devfreq);
		dev_err(dev, "failed to add devfreq device: %d\n", ret);
		goto err;
	}

	ret = imx_bus_init_icc(dev);
	if (ret)
		goto err;

	return 0;

err:
	dev_pm_opp_of_remove_table(dev);
	return ret;
}

static const struct of_device_id imx_bus_of_match[] = {
	{ .compatible = "fsl,imx8mq-noc", .data = "imx8mq-interconnect", },
	{ .compatible = "fsl,imx8mm-noc", .data = "imx8mm-interconnect", },
	{ .compatible = "fsl,imx8mn-noc", .data = "imx8mn-interconnect", },
	{ .compatible = "fsl,imx8mp-noc", .data = "imx8mp-interconnect", },
	{ .compatible = "fsl,imx8m-noc", },
	{ .compatible = "fsl,imx8m-nic", },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, imx_bus_of_match);

static struct platform_driver imx_bus_platdrv = {
	.probe		= imx_bus_probe,
	.driver = {
		.name	= "imx-bus-devfreq",
		.of_match_table = imx_bus_of_match,
	},
};
module_platform_driver(imx_bus_platdrv);

MODULE_DESCRIPTION("Generic i.MX bus frequency scaling driver");
MODULE_AUTHOR("Leonard Crestez <leonard.crestez@nxp.com>");
MODULE_LICENSE("GPL v2");