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/mutex.h>
13 #include <linux/of.h>
14 #include <linux/platform_device.h>
15 #include <linux/pm_domain.h>
16 #include <linux/slab.h>
17 #include <linux/soc/ti/ti_sci_protocol.h>
18 #include <dt-bindings/soc/ti,sci_pm_domain.h>
19
20 /**
21 * struct ti_sci_genpd_dev_data: holds data needed for every device attached
22 * to this genpd
23 * @idx: index of the device that identifies it with the system
24 * control processor.
25 * @exclusive: Permissions for exclusive request or shared request of the
26 * device.
27 */
28 struct ti_sci_genpd_dev_data {
29 int idx;
30 u8 exclusive;
31 };
32
33 /**
34 * struct ti_sci_pm_domain: TI specific data needed for power domain
35 * @ti_sci: handle to TI SCI protocol driver that provides ops to
36 * communicate with system control processor.
37 * @dev: pointer to dev for the driver for devm allocs
38 * @pd: generic_pm_domain for use with the genpd framework
39 */
40 struct ti_sci_pm_domain {
41 const struct ti_sci_handle *ti_sci;
42 struct device *dev;
43 struct generic_pm_domain pd;
44 };
45
46 #define genpd_to_ti_sci_pd(gpd) container_of(gpd, struct ti_sci_pm_domain, pd)
47
48 /**
49 * ti_sci_dev_id(): get prepopulated ti_sci id from struct dev
50 * @dev: pointer to device associated with this genpd
51 *
52 * Returns device_id stored from ti,sci_id property
53 */
ti_sci_dev_id(struct device * dev)54 static int ti_sci_dev_id(struct device *dev)
55 {
56 struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
57 struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
58
59 return sci_dev_data->idx;
60 }
61
is_ti_sci_dev_exclusive(struct device * dev)62 static u8 is_ti_sci_dev_exclusive(struct device *dev)
63 {
64 struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
65 struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
66
67 return sci_dev_data->exclusive;
68 }
69
70 /**
71 * ti_sci_dev_to_sci_handle(): get pointer to ti_sci_handle
72 * @dev: pointer to device associated with this genpd
73 *
74 * Returns ti_sci_handle to be used to communicate with system
75 * control processor.
76 */
ti_sci_dev_to_sci_handle(struct device * dev)77 static const struct ti_sci_handle *ti_sci_dev_to_sci_handle(struct device *dev)
78 {
79 struct generic_pm_domain *pd = pd_to_genpd(dev->pm_domain);
80 struct ti_sci_pm_domain *ti_sci_genpd = genpd_to_ti_sci_pd(pd);
81
82 return ti_sci_genpd->ti_sci;
83 }
84
85 /**
86 * ti_sci_dev_start(): genpd device start hook called to turn device on
87 * @dev: pointer to device associated with this genpd to be powered on
88 */
ti_sci_dev_start(struct device * dev)89 static int ti_sci_dev_start(struct device *dev)
90 {
91 const struct ti_sci_handle *ti_sci = ti_sci_dev_to_sci_handle(dev);
92 int idx = ti_sci_dev_id(dev);
93
94 if (is_ti_sci_dev_exclusive(dev))
95 return ti_sci->ops.dev_ops.get_device_exclusive(ti_sci, idx);
96 else
97 return ti_sci->ops.dev_ops.get_device(ti_sci, idx);
98 }
99
100 /**
101 * ti_sci_dev_stop(): genpd device stop hook called to turn device off
102 * @dev: pointer to device associated with this genpd to be powered off
103 */
ti_sci_dev_stop(struct device * dev)104 static int ti_sci_dev_stop(struct device *dev)
105 {
106 const struct ti_sci_handle *ti_sci = ti_sci_dev_to_sci_handle(dev);
107 int idx = ti_sci_dev_id(dev);
108
109 return ti_sci->ops.dev_ops.put_device(ti_sci, idx);
110 }
111
ti_sci_pd_attach_dev(struct generic_pm_domain * domain,struct device * dev)112 static int ti_sci_pd_attach_dev(struct generic_pm_domain *domain,
113 struct device *dev)
114 {
115 struct device_node *np = dev->of_node;
116 struct of_phandle_args pd_args;
117 struct ti_sci_pm_domain *ti_sci_genpd = genpd_to_ti_sci_pd(domain);
118 const struct ti_sci_handle *ti_sci = ti_sci_genpd->ti_sci;
119 struct ti_sci_genpd_dev_data *sci_dev_data;
120 struct generic_pm_domain_data *genpd_data;
121 int idx, ret = 0;
122
123 ret = of_parse_phandle_with_args(np, "power-domains",
124 "#power-domain-cells", 0, &pd_args);
125 if (ret < 0)
126 return ret;
127
128 if (pd_args.args_count != 1 && pd_args.args_count != 2)
129 return -EINVAL;
130
131 idx = pd_args.args[0];
132
133 /*
134 * Check the validity of the requested idx, if the index is not valid
135 * the PMMC will return a NAK here and we will not allocate it.
136 */
137 ret = ti_sci->ops.dev_ops.is_valid(ti_sci, idx);
138 if (ret)
139 return -EINVAL;
140
141 sci_dev_data = kzalloc(sizeof(*sci_dev_data), GFP_KERNEL);
142 if (!sci_dev_data)
143 return -ENOMEM;
144
145 sci_dev_data->idx = idx;
146 /* Enable the exclusive permissions by default */
147 sci_dev_data->exclusive = TI_SCI_PD_EXCLUSIVE;
148 if (pd_args.args_count == 2)
149 sci_dev_data->exclusive = pd_args.args[1] & 0x1;
150
151 genpd_data = dev_gpd_data(dev);
152 genpd_data->data = sci_dev_data;
153
154 return 0;
155 }
156
ti_sci_pd_detach_dev(struct generic_pm_domain * domain,struct device * dev)157 static void ti_sci_pd_detach_dev(struct generic_pm_domain *domain,
158 struct device *dev)
159 {
160 struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
161 struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
162
163 kfree(sci_dev_data);
164 genpd_data->data = NULL;
165 }
166
167 static const struct of_device_id ti_sci_pm_domain_matches[] = {
168 { .compatible = "ti,sci-pm-domain", },
169 { },
170 };
171 MODULE_DEVICE_TABLE(of, ti_sci_pm_domain_matches);
172
ti_sci_pm_domain_probe(struct platform_device * pdev)173 static int ti_sci_pm_domain_probe(struct platform_device *pdev)
174 {
175 struct device *dev = &pdev->dev;
176 struct device_node *np = dev->of_node;
177 struct ti_sci_pm_domain *ti_sci_pd;
178 int ret;
179
180 ti_sci_pd = devm_kzalloc(dev, sizeof(*ti_sci_pd), GFP_KERNEL);
181 if (!ti_sci_pd)
182 return -ENOMEM;
183
184 ti_sci_pd->ti_sci = devm_ti_sci_get_handle(dev);
185 if (IS_ERR(ti_sci_pd->ti_sci))
186 return PTR_ERR(ti_sci_pd->ti_sci);
187
188 ti_sci_pd->dev = dev;
189
190 ti_sci_pd->pd.name = "ti_sci_pd";
191
192 ti_sci_pd->pd.attach_dev = ti_sci_pd_attach_dev;
193 ti_sci_pd->pd.detach_dev = ti_sci_pd_detach_dev;
194
195 ti_sci_pd->pd.dev_ops.start = ti_sci_dev_start;
196 ti_sci_pd->pd.dev_ops.stop = ti_sci_dev_stop;
197
198 pm_genpd_init(&ti_sci_pd->pd, NULL, true);
199
200 ret = of_genpd_add_provider_simple(np, &ti_sci_pd->pd);
201
202 return ret;
203 }
204
205 static struct platform_driver ti_sci_pm_domains_driver = {
206 .probe = ti_sci_pm_domain_probe,
207 .driver = {
208 .name = "ti_sci_pm_domains",
209 .of_match_table = ti_sci_pm_domain_matches,
210 },
211 };
212 module_platform_driver(ti_sci_pm_domains_driver);
213 MODULE_LICENSE("GPL v2");
214 MODULE_DESCRIPTION("TI System Control Interface (SCI) Power Domain driver");
215 MODULE_AUTHOR("Dave Gerlach");
216
