Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: 390aa13391e4eb5a6bab6306b63d1d7f31e43a4a (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
/*
 * SCPI Generic power domain support.
 *
 * Copyright (C) 2016 ARM Ltd.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/pm_domain.h>
#include <linux/scpi_protocol.h>

struct scpi_pm_domain {
	struct generic_pm_domain genpd;
	struct scpi_ops *ops;
	u32 domain;
	char name[30];
};

/*
 * These device power state values are not well-defined in the specification.
 * In case, different implementations use different values, we can make these
 * specific to compatibles rather than getting these values from device tree.
 */
enum scpi_power_domain_state {
	SCPI_PD_STATE_ON = 0,
	SCPI_PD_STATE_OFF = 3,
};

#define to_scpi_pd(gpd) container_of(gpd, struct scpi_pm_domain, genpd)

static int scpi_pd_power(struct scpi_pm_domain *pd, bool power_on)
{
	int ret;
	enum scpi_power_domain_state state;

	if (power_on)
		state = SCPI_PD_STATE_ON;
	else
		state = SCPI_PD_STATE_OFF;

	ret = pd->ops->device_set_power_state(pd->domain, state);
	if (ret)
		return ret;

	return !(state == pd->ops->device_get_power_state(pd->domain));
}

static int scpi_pd_power_on(struct generic_pm_domain *domain)
{
	struct scpi_pm_domain *pd = to_scpi_pd(domain);

	return scpi_pd_power(pd, true);
}

static int scpi_pd_power_off(struct generic_pm_domain *domain)
{
	struct scpi_pm_domain *pd = to_scpi_pd(domain);

	return scpi_pd_power(pd, false);
}

static int scpi_pm_domain_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct scpi_pm_domain *scpi_pd;
	struct genpd_onecell_data *scpi_pd_data;
	struct generic_pm_domain **domains;
	struct scpi_ops *scpi_ops;
	int ret, num_domains, i;

	scpi_ops = get_scpi_ops();
	if (!scpi_ops)
		return -EPROBE_DEFER;

	if (!np) {
		dev_err(dev, "device tree node not found\n");
		return -ENODEV;
	}

	if (!scpi_ops->device_set_power_state ||
	    !scpi_ops->device_get_power_state) {
		dev_err(dev, "power domains not supported in the firmware\n");
		return -ENODEV;
	}

	ret = of_property_read_u32(np, "num-domains", &num_domains);
	if (ret) {
		dev_err(dev, "number of domains not found\n");
		return -EINVAL;
	}

	scpi_pd = devm_kcalloc(dev, num_domains, sizeof(*scpi_pd), GFP_KERNEL);
	if (!scpi_pd)
		return -ENOMEM;

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

	domains = devm_kcalloc(dev, num_domains, sizeof(*domains), GFP_KERNEL);
	if (!domains)
		return -ENOMEM;

	for (i = 0; i < num_domains; i++, scpi_pd++) {
		domains[i] = &scpi_pd->genpd;

		scpi_pd->domain = i;
		scpi_pd->ops = scpi_ops;
		sprintf(scpi_pd->name, "%pOFn.%d", np, i);
		scpi_pd->genpd.name = scpi_pd->name;
		scpi_pd->genpd.power_off = scpi_pd_power_off;
		scpi_pd->genpd.power_on = scpi_pd_power_on;

		/*
		 * Treat all power domains as off at boot.
		 *
		 * The SCP firmware itself may have switched on some domains,
		 * but for reference counting purpose, keep it this way.
		 */
		pm_genpd_init(&scpi_pd->genpd, NULL, true);
	}

	scpi_pd_data->domains = domains;
	scpi_pd_data->num_domains = num_domains;

	of_genpd_add_provider_onecell(np, scpi_pd_data);

	return 0;
}

static const struct of_device_id scpi_power_domain_ids[] = {
	{ .compatible = "arm,scpi-power-domains", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, scpi_power_domain_ids);

static struct platform_driver scpi_power_domain_driver = {
	.driver	= {
		.name = "scpi_power_domain",
		.of_match_table = scpi_power_domain_ids,
	},
	.probe = scpi_pm_domain_probe,
};
module_platform_driver(scpi_power_domain_driver);

MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
MODULE_DESCRIPTION("ARM SCPI power domain driver");
MODULE_LICENSE("GPL v2");