1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * TI SCI Generic Power Domain Driver
4  *
5  * Copyright (C) 2015-2017 Texas Instruments Incorporated - http://www.ti.com/
6  *	J Keerthy <j-keerthy@ti.com>
7  *	Dave Gerlach <d-gerlach@ti.com>
8  */
9 
10 #include <linux/err.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/platform_device.h>
14 #include <linux/pm_domain.h>
15 #include <linux/slab.h>
16 #include <linux/soc/ti/ti_sci_protocol.h>
17 #include <dt-bindings/soc/ti,sci_pm_domain.h>
18 
19 /**
20  * struct ti_sci_genpd_provider: holds common TI SCI genpd provider data
21  * @ti_sci: handle to TI SCI protocol driver that provides ops to
22  *	    communicate with system control processor.
23  * @dev: pointer to dev for the driver for devm allocs
24  * @pd_list: list of all the power domains on the device
25  * @data: onecell data for genpd core
26  */
27 struct ti_sci_genpd_provider {
28 	const struct ti_sci_handle *ti_sci;
29 	struct device *dev;
30 	struct list_head pd_list;
31 	struct genpd_onecell_data data;
32 };
33 
34 /**
35  * struct ti_sci_pm_domain: TI specific data needed for power domain
36  * @idx: index of the device that identifies it with the system
37  *	 control processor.
38  * @exclusive: Permissions for exclusive request or shared request of the
39  *	       device.
40  * @pd: generic_pm_domain for use with the genpd framework
41  * @node: link for the genpd list
42  * @parent: link to the parent TI SCI genpd provider
43  */
44 struct ti_sci_pm_domain {
45 	int idx;
46 	u8 exclusive;
47 	struct generic_pm_domain pd;
48 	struct list_head node;
49 	struct ti_sci_genpd_provider *parent;
50 };
51 
52 #define genpd_to_ti_sci_pd(gpd) container_of(gpd, struct ti_sci_pm_domain, pd)
53 
54 /*
55  * ti_sci_pd_power_off(): genpd power down hook
56  * @domain: pointer to the powerdomain to power off
57  */
58 static int ti_sci_pd_power_off(struct generic_pm_domain *domain)
59 {
60 	struct ti_sci_pm_domain *pd = genpd_to_ti_sci_pd(domain);
61 	const struct ti_sci_handle *ti_sci = pd->parent->ti_sci;
62 
63 	return ti_sci->ops.dev_ops.put_device(ti_sci, pd->idx);
64 }
65 
66 /*
67  * ti_sci_pd_power_on(): genpd power up hook
68  * @domain: pointer to the powerdomain to power on
69  */
70 static int ti_sci_pd_power_on(struct generic_pm_domain *domain)
71 {
72 	struct ti_sci_pm_domain *pd = genpd_to_ti_sci_pd(domain);
73 	const struct ti_sci_handle *ti_sci = pd->parent->ti_sci;
74 
75 	if (pd->exclusive)
76 		return ti_sci->ops.dev_ops.get_device_exclusive(ti_sci,
77 								pd->idx);
78 	else
79 		return ti_sci->ops.dev_ops.get_device(ti_sci, pd->idx);
80 }
81 
82 /*
83  * ti_sci_pd_xlate(): translation service for TI SCI genpds
84  * @genpdspec: DT identification data for the genpd
85  * @data: genpd core data for all the powerdomains on the device
86  */
87 static struct generic_pm_domain *ti_sci_pd_xlate(
88 					struct of_phandle_args *genpdspec,
89 					void *data)
90 {
91 	struct genpd_onecell_data *genpd_data = data;
92 	unsigned int idx = genpdspec->args[0];
93 
94 	if (genpdspec->args_count != 1 && genpdspec->args_count != 2)
95 		return ERR_PTR(-EINVAL);
96 
97 	if (idx >= genpd_data->num_domains) {
98 		pr_err("%s: invalid domain index %u\n", __func__, idx);
99 		return ERR_PTR(-EINVAL);
100 	}
101 
102 	if (!genpd_data->domains[idx])
103 		return ERR_PTR(-ENOENT);
104 
105 	genpd_to_ti_sci_pd(genpd_data->domains[idx])->exclusive =
106 		genpdspec->args[1];
107 
108 	return genpd_data->domains[idx];
109 }
110 
111 static const struct of_device_id ti_sci_pm_domain_matches[] = {
112 	{ .compatible = "ti,sci-pm-domain", },
113 	{ },
114 };
115 MODULE_DEVICE_TABLE(of, ti_sci_pm_domain_matches);
116 
117 static bool ti_sci_pm_idx_exists(struct ti_sci_genpd_provider *pd_provider, u32 idx)
118 {
119 	struct ti_sci_pm_domain *pd;
120 
121 	list_for_each_entry(pd, &pd_provider->pd_list, node) {
122 		if (pd->idx == idx)
123 			return true;
124 	}
125 
126 	return false;
127 }
128 
129 static int ti_sci_pm_domain_probe(struct platform_device *pdev)
130 {
131 	struct device *dev = &pdev->dev;
132 	struct ti_sci_genpd_provider *pd_provider;
133 	struct ti_sci_pm_domain *pd;
134 	struct device_node *np;
135 	struct of_phandle_args args;
136 	int ret;
137 	u32 max_id = 0;
138 	int index;
139 
140 	pd_provider = devm_kzalloc(dev, sizeof(*pd_provider), GFP_KERNEL);
141 	if (!pd_provider)
142 		return -ENOMEM;
143 
144 	pd_provider->ti_sci = devm_ti_sci_get_handle(dev);
145 	if (IS_ERR(pd_provider->ti_sci))
146 		return PTR_ERR(pd_provider->ti_sci);
147 
148 	pd_provider->dev = dev;
149 
150 	INIT_LIST_HEAD(&pd_provider->pd_list);
151 
152 	/* Find highest device ID used for power domains */
153 	for_each_node_with_property(np, "power-domains") {
154 		index = 0;
155 
156 		while (1) {
157 			ret = of_parse_phandle_with_args(np, "power-domains",
158 							 "#power-domain-cells",
159 							 index, &args);
160 			if (ret)
161 				break;
162 
163 			if (args.args_count >= 1 && args.np == dev->of_node) {
164 				of_node_put(args.np);
165 				if (args.args[0] > max_id) {
166 					max_id = args.args[0];
167 				} else {
168 					if (ti_sci_pm_idx_exists(pd_provider, args.args[0])) {
169 						index++;
170 						continue;
171 					}
172 				}
173 
174 				pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
175 				if (!pd)
176 					return -ENOMEM;
177 
178 				pd->pd.name = devm_kasprintf(dev, GFP_KERNEL,
179 							     "pd:%d",
180 							     args.args[0]);
181 				if (!pd->pd.name)
182 					return -ENOMEM;
183 
184 				pd->pd.power_off = ti_sci_pd_power_off;
185 				pd->pd.power_on = ti_sci_pd_power_on;
186 				pd->idx = args.args[0];
187 				pd->parent = pd_provider;
188 
189 				pm_genpd_init(&pd->pd, NULL, true);
190 
191 				list_add(&pd->node, &pd_provider->pd_list);
192 			} else {
193 				of_node_put(args.np);
194 			}
195 
196 			index++;
197 		}
198 	}
199 
200 	pd_provider->data.domains =
201 		devm_kcalloc(dev, max_id + 1,
202 			     sizeof(*pd_provider->data.domains),
203 			     GFP_KERNEL);
204 	if (!pd_provider->data.domains)
205 		return -ENOMEM;
206 
207 	pd_provider->data.num_domains = max_id + 1;
208 	pd_provider->data.xlate = ti_sci_pd_xlate;
209 
210 	list_for_each_entry(pd, &pd_provider->pd_list, node)
211 		pd_provider->data.domains[pd->idx] = &pd->pd;
212 
213 	return of_genpd_add_provider_onecell(dev->of_node, &pd_provider->data);
214 }
215 
216 static struct platform_driver ti_sci_pm_domains_driver = {
217 	.probe = ti_sci_pm_domain_probe,
218 	.driver = {
219 		.name = "ti_sci_pm_domains",
220 		.of_match_table = ti_sci_pm_domain_matches,
221 	},
222 };
223 module_platform_driver(ti_sci_pm_domains_driver);
224 MODULE_LICENSE("GPL v2");
225 MODULE_DESCRIPTION("TI System Control Interface (SCI) Power Domain driver");
226 MODULE_AUTHOR("Dave Gerlach");
227