1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright 2019 NXP |
4 | */ |
5 | |
6 | #include <linux/clk.h> |
7 | #include <linux/devfreq.h> |
8 | #include <linux/device.h> |
9 | #include <linux/module.h> |
10 | #include <linux/of.h> |
11 | #include <linux/pm_opp.h> |
12 | #include <linux/platform_device.h> |
13 | #include <linux/slab.h> |
14 | |
15 | struct imx_bus { |
16 | struct devfreq_dev_profile profile; |
17 | struct devfreq *devfreq; |
18 | struct clk *clk; |
19 | struct platform_device *icc_pdev; |
20 | }; |
21 | |
22 | static int imx_bus_target(struct device *dev, |
23 | unsigned long *freq, u32 flags) |
24 | { |
25 | struct dev_pm_opp *new_opp; |
26 | int ret; |
27 | |
28 | new_opp = devfreq_recommended_opp(dev, freq, flags); |
29 | if (IS_ERR(ptr: new_opp)) { |
30 | ret = PTR_ERR(ptr: new_opp); |
31 | dev_err(dev, "failed to get recommended opp: %d\n" , ret); |
32 | return ret; |
33 | } |
34 | dev_pm_opp_put(opp: new_opp); |
35 | |
36 | return dev_pm_opp_set_rate(dev, target_freq: *freq); |
37 | } |
38 | |
39 | static int imx_bus_get_cur_freq(struct device *dev, unsigned long *freq) |
40 | { |
41 | struct imx_bus *priv = dev_get_drvdata(dev); |
42 | |
43 | *freq = clk_get_rate(clk: priv->clk); |
44 | |
45 | return 0; |
46 | } |
47 | |
48 | static void imx_bus_exit(struct device *dev) |
49 | { |
50 | struct imx_bus *priv = dev_get_drvdata(dev); |
51 | |
52 | dev_pm_opp_of_remove_table(dev); |
53 | platform_device_unregister(priv->icc_pdev); |
54 | } |
55 | |
56 | /* imx_bus_init_icc() - register matching icc provider if required */ |
57 | static int imx_bus_init_icc(struct device *dev) |
58 | { |
59 | struct imx_bus *priv = dev_get_drvdata(dev); |
60 | const char *icc_driver_name; |
61 | |
62 | if (!of_get_property(node: dev->of_node, name: "#interconnect-cells" , NULL)) |
63 | return 0; |
64 | if (!IS_ENABLED(CONFIG_INTERCONNECT_IMX)) { |
65 | dev_warn(dev, "imx interconnect drivers disabled\n" ); |
66 | return 0; |
67 | } |
68 | |
69 | icc_driver_name = of_device_get_match_data(dev); |
70 | if (!icc_driver_name) { |
71 | dev_err(dev, "unknown interconnect driver\n" ); |
72 | return 0; |
73 | } |
74 | |
75 | priv->icc_pdev = platform_device_register_data( |
76 | parent: dev, name: icc_driver_name, id: -1, NULL, size: 0); |
77 | if (IS_ERR(ptr: priv->icc_pdev)) { |
78 | dev_err(dev, "failed to register icc provider %s: %ld\n" , |
79 | icc_driver_name, PTR_ERR(priv->icc_pdev)); |
80 | return PTR_ERR(ptr: priv->icc_pdev); |
81 | } |
82 | |
83 | return 0; |
84 | } |
85 | |
86 | static int imx_bus_probe(struct platform_device *pdev) |
87 | { |
88 | struct device *dev = &pdev->dev; |
89 | struct imx_bus *priv; |
90 | const char *gov = DEVFREQ_GOV_USERSPACE; |
91 | int ret; |
92 | |
93 | priv = devm_kzalloc(dev, size: sizeof(*priv), GFP_KERNEL); |
94 | if (!priv) |
95 | return -ENOMEM; |
96 | |
97 | /* |
98 | * Fetch the clock to adjust but don't explicitly enable. |
99 | * |
100 | * For imx bus clock clk_set_rate is safe no matter if the clock is on |
101 | * or off and some peripheral side-buses might be off unless enabled by |
102 | * drivers for devices on those specific buses. |
103 | * |
104 | * Rate adjustment on a disabled bus clock just takes effect later. |
105 | */ |
106 | priv->clk = devm_clk_get(dev, NULL); |
107 | if (IS_ERR(ptr: priv->clk)) { |
108 | ret = PTR_ERR(ptr: priv->clk); |
109 | dev_err(dev, "failed to fetch clk: %d\n" , ret); |
110 | return ret; |
111 | } |
112 | platform_set_drvdata(pdev, data: priv); |
113 | |
114 | ret = dev_pm_opp_of_add_table(dev); |
115 | if (ret < 0) { |
116 | dev_err(dev, "failed to get OPP table\n" ); |
117 | return ret; |
118 | } |
119 | |
120 | priv->profile.target = imx_bus_target; |
121 | priv->profile.exit = imx_bus_exit; |
122 | priv->profile.get_cur_freq = imx_bus_get_cur_freq; |
123 | priv->profile.initial_freq = clk_get_rate(clk: priv->clk); |
124 | |
125 | priv->devfreq = devm_devfreq_add_device(dev, profile: &priv->profile, |
126 | governor_name: gov, NULL); |
127 | if (IS_ERR(ptr: priv->devfreq)) { |
128 | ret = PTR_ERR(ptr: priv->devfreq); |
129 | dev_err(dev, "failed to add devfreq device: %d\n" , ret); |
130 | goto err; |
131 | } |
132 | |
133 | ret = imx_bus_init_icc(dev); |
134 | if (ret) |
135 | goto err; |
136 | |
137 | return 0; |
138 | |
139 | err: |
140 | dev_pm_opp_of_remove_table(dev); |
141 | return ret; |
142 | } |
143 | |
144 | static const struct of_device_id imx_bus_of_match[] = { |
145 | { .compatible = "fsl,imx8mq-noc" , .data = "imx8mq-interconnect" , }, |
146 | { .compatible = "fsl,imx8mm-noc" , .data = "imx8mm-interconnect" , }, |
147 | { .compatible = "fsl,imx8mn-noc" , .data = "imx8mn-interconnect" , }, |
148 | { .compatible = "fsl,imx8mp-noc" , .data = "imx8mp-interconnect" , }, |
149 | { .compatible = "fsl,imx8m-noc" , }, |
150 | { .compatible = "fsl,imx8m-nic" , }, |
151 | { /* sentinel */ }, |
152 | }; |
153 | MODULE_DEVICE_TABLE(of, imx_bus_of_match); |
154 | |
155 | static struct platform_driver imx_bus_platdrv = { |
156 | .probe = imx_bus_probe, |
157 | .driver = { |
158 | .name = "imx-bus-devfreq" , |
159 | .of_match_table = imx_bus_of_match, |
160 | }, |
161 | }; |
162 | module_platform_driver(imx_bus_platdrv); |
163 | |
164 | MODULE_DESCRIPTION("Generic i.MX bus frequency scaling driver" ); |
165 | MODULE_AUTHOR("Leonard Crestez <leonard.crestez@nxp.com>" ); |
166 | MODULE_LICENSE("GPL v2" ); |
167 | |