1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Exynos generic interconnect provider driver
4 *
5 * Copyright (c) 2020 Samsung Electronics Co., Ltd.
6 *
7 * Authors: Artur Świgoń <a.swigon@samsung.com>
8 * Sylwester Nawrocki <s.nawrocki@samsung.com>
9 */
10 #include <linux/device.h>
11 #include <linux/interconnect-provider.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/platform_device.h>
15 #include <linux/pm_qos.h>
16 #include <linux/slab.h>
17
18 #define EXYNOS_ICC_DEFAULT_BUS_CLK_RATIO 8
19
20 struct exynos_icc_priv {
21 struct device *dev;
22
23 /* One interconnect node per provider */
24 struct icc_provider provider;
25 struct icc_node *node;
26
27 struct dev_pm_qos_request qos_req;
28 u32 bus_clk_ratio;
29 };
30
exynos_icc_get_parent(struct device_node * np)31 static struct icc_node *exynos_icc_get_parent(struct device_node *np)
32 {
33 struct of_phandle_args args;
34 struct icc_node_data *icc_node_data;
35 struct icc_node *icc_node;
36 int num, ret;
37
38 num = of_count_phandle_with_args(np, "interconnects",
39 "#interconnect-cells");
40 if (num < 1)
41 return NULL; /* parent nodes are optional */
42
43 /* Get the interconnect target node */
44 ret = of_parse_phandle_with_args(np, "interconnects",
45 "#interconnect-cells", 0, &args);
46 if (ret < 0)
47 return ERR_PTR(ret);
48
49 icc_node_data = of_icc_get_from_provider(&args);
50 of_node_put(args.np);
51
52 if (IS_ERR(icc_node_data))
53 return ERR_CAST(icc_node_data);
54
55 icc_node = icc_node_data->node;
56 kfree(icc_node_data);
57
58 return icc_node;
59 }
60
exynos_generic_icc_set(struct icc_node * src,struct icc_node * dst)61 static int exynos_generic_icc_set(struct icc_node *src, struct icc_node *dst)
62 {
63 struct exynos_icc_priv *src_priv = src->data, *dst_priv = dst->data;
64 s32 src_freq = max(src->avg_bw, src->peak_bw) / src_priv->bus_clk_ratio;
65 s32 dst_freq = max(dst->avg_bw, dst->peak_bw) / dst_priv->bus_clk_ratio;
66 int ret;
67
68 ret = dev_pm_qos_update_request(&src_priv->qos_req, src_freq);
69 if (ret < 0) {
70 dev_err(src_priv->dev, "failed to update PM QoS of %s (src)\n",
71 src->name);
72 return ret;
73 }
74
75 ret = dev_pm_qos_update_request(&dst_priv->qos_req, dst_freq);
76 if (ret < 0) {
77 dev_err(dst_priv->dev, "failed to update PM QoS of %s (dst)\n",
78 dst->name);
79 return ret;
80 }
81
82 return 0;
83 }
84
exynos_generic_icc_xlate(struct of_phandle_args * spec,void * data)85 static struct icc_node *exynos_generic_icc_xlate(struct of_phandle_args *spec,
86 void *data)
87 {
88 struct exynos_icc_priv *priv = data;
89
90 if (spec->np != priv->dev->parent->of_node)
91 return ERR_PTR(-EINVAL);
92
93 return priv->node;
94 }
95
exynos_generic_icc_remove(struct platform_device * pdev)96 static int exynos_generic_icc_remove(struct platform_device *pdev)
97 {
98 struct exynos_icc_priv *priv = platform_get_drvdata(pdev);
99 struct icc_node *parent_node, *node = priv->node;
100
101 parent_node = exynos_icc_get_parent(priv->dev->parent->of_node);
102 if (parent_node && !IS_ERR(parent_node))
103 icc_link_destroy(node, parent_node);
104
105 icc_nodes_remove(&priv->provider);
106 icc_provider_del(&priv->provider);
107
108 return 0;
109 }
110
exynos_generic_icc_probe(struct platform_device * pdev)111 static int exynos_generic_icc_probe(struct platform_device *pdev)
112 {
113 struct device *bus_dev = pdev->dev.parent;
114 struct exynos_icc_priv *priv;
115 struct icc_provider *provider;
116 struct icc_node *icc_node, *icc_parent_node;
117 int ret;
118
119 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
120 if (!priv)
121 return -ENOMEM;
122
123 priv->dev = &pdev->dev;
124 platform_set_drvdata(pdev, priv);
125
126 provider = &priv->provider;
127
128 provider->set = exynos_generic_icc_set;
129 provider->aggregate = icc_std_aggregate;
130 provider->xlate = exynos_generic_icc_xlate;
131 provider->dev = bus_dev;
132 provider->inter_set = true;
133 provider->data = priv;
134
135 ret = icc_provider_add(provider);
136 if (ret < 0)
137 return ret;
138
139 icc_node = icc_node_create(pdev->id);
140 if (IS_ERR(icc_node)) {
141 ret = PTR_ERR(icc_node);
142 goto err_prov_del;
143 }
144
145 priv->node = icc_node;
146 icc_node->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOFn",
147 bus_dev->of_node);
148 if (of_property_read_u32(bus_dev->of_node, "samsung,data-clock-ratio",
149 &priv->bus_clk_ratio))
150 priv->bus_clk_ratio = EXYNOS_ICC_DEFAULT_BUS_CLK_RATIO;
151
152 /*
153 * Register a PM QoS request for the parent (devfreq) device.
154 */
155 ret = dev_pm_qos_add_request(bus_dev, &priv->qos_req,
156 DEV_PM_QOS_MIN_FREQUENCY, 0);
157 if (ret < 0)
158 goto err_node_del;
159
160 icc_node->data = priv;
161 icc_node_add(icc_node, provider);
162
163 icc_parent_node = exynos_icc_get_parent(bus_dev->of_node);
164 if (IS_ERR(icc_parent_node)) {
165 ret = PTR_ERR(icc_parent_node);
166 goto err_pmqos_del;
167 }
168 if (icc_parent_node) {
169 ret = icc_link_create(icc_node, icc_parent_node->id);
170 if (ret < 0)
171 goto err_pmqos_del;
172 }
173
174 return 0;
175
176 err_pmqos_del:
177 dev_pm_qos_remove_request(&priv->qos_req);
178 err_node_del:
179 icc_nodes_remove(provider);
180 err_prov_del:
181 icc_provider_del(provider);
182 return ret;
183 }
184
185 static struct platform_driver exynos_generic_icc_driver = {
186 .driver = {
187 .name = "exynos-generic-icc",
188 .sync_state = icc_sync_state,
189 },
190 .probe = exynos_generic_icc_probe,
191 .remove = exynos_generic_icc_remove,
192 };
193 module_platform_driver(exynos_generic_icc_driver);
194
195 MODULE_DESCRIPTION("Exynos generic interconnect driver");
196 MODULE_AUTHOR("Artur Świgoń <a.swigon@samsung.com>");
197 MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
198 MODULE_LICENSE("GPL v2");
199 MODULE_ALIAS("platform:exynos-generic-icc");
200