summaryrefslogtreecommitdiffstats
path: root/drivers/soc/bcm/raspberrypi-power.c
blob: a78dfe0a2b503c3a98e09f48c606f45ea184a513 (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
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
/* (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Authors:
 * Alexander Aring <aar@pengutronix.de>
 * Eric Anholt <eric@anholt.net>
 */

#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <dt-bindings/power/raspberrypi-power.h>
#include <soc/bcm2835/raspberrypi-firmware.h>

/*
 * Firmware indices for the old power domains interface.  Only a few
 * of them were actually implemented.
 */
#define RPI_OLD_POWER_DOMAIN_USB		3
#define RPI_OLD_POWER_DOMAIN_V3D		10

struct rpi_power_domain {
	u32 domain;
	bool enabled;
	bool old_interface;
	struct generic_pm_domain base;
	struct rpi_firmware *fw;
};

struct rpi_power_domains {
	bool has_new_interface;
	struct genpd_onecell_data xlate;
	struct rpi_firmware *fw;
	struct rpi_power_domain domains[RPI_POWER_DOMAIN_COUNT];
};

/*
 * Packet definition used by RPI_FIRMWARE_SET_POWER_STATE and
 * RPI_FIRMWARE_SET_DOMAIN_STATE
 */
struct rpi_power_domain_packet {
	u32 domain;
	u32 on;
};

/*
 * Asks the firmware to enable or disable power on a specific power
 * domain.
 */
static int rpi_firmware_set_power(struct rpi_power_domain *rpi_domain, bool on)
{
	struct rpi_power_domain_packet packet;

	packet.domain = rpi_domain->domain;
	packet.on = on;
	return rpi_firmware_property(rpi_domain->fw,
				     rpi_domain->old_interface ?
				     RPI_FIRMWARE_SET_POWER_STATE :
				     RPI_FIRMWARE_SET_DOMAIN_STATE,
				     &packet, sizeof(packet));
}

static int rpi_domain_off(struct generic_pm_domain *domain)
{
	struct rpi_power_domain *rpi_domain =
		container_of(domain, struct rpi_power_domain, base);

	return rpi_firmware_set_power(rpi_domain, false);
}

static int rpi_domain_on(struct generic_pm_domain *domain)
{
	struct rpi_power_domain *rpi_domain =
		container_of(domain, struct rpi_power_domain, base);

	return rpi_firmware_set_power(rpi_domain, true);
}

static void rpi_common_init_power_domain(struct rpi_power_domains *rpi_domains,
					 int xlate_index, const char *name)
{
	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];

	dom->fw = rpi_domains->fw;

	dom->base.name = name;
	dom->base.power_on = rpi_domain_on;
	dom->base.power_off = rpi_domain_off;

	/*
	 * Treat all power domains as off at boot.
	 *
	 * The firmware itself may be keeping some domains on, but
	 * from Linux's perspective all we control is the refcounts
	 * that we give to the firmware, and we can't ask the firmware
	 * to turn off something that we haven't ourselves turned on.
	 */
	pm_genpd_init(&dom->base, NULL, true);

	rpi_domains->xlate.domains[xlate_index] = &dom->base;
}

static void rpi_init_power_domain(struct rpi_power_domains *rpi_domains,
				  int xlate_index, const char *name)
{
	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];

	if (!rpi_domains->has_new_interface)
		return;

	/* The DT binding index is the firmware's domain index minus one. */
	dom->domain = xlate_index + 1;

	rpi_common_init_power_domain(rpi_domains, xlate_index, name);
}

static void rpi_init_old_power_domain(struct rpi_power_domains *rpi_domains,
				      int xlate_index, int domain,
				      const char *name)
{
	struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];

	dom->old_interface = true;
	dom->domain = domain;

	rpi_common_init_power_domain(rpi_domains, xlate_index, name);
}

/*
 * Detects whether the firmware supports the new power domains interface.
 *
 * The firmware doesn't actually return an error on an unknown tag,
 * and just skips over it, so we do the detection by putting an
 * unexpected value in the return field and checking if it was
 * unchanged.
 */
static bool
rpi_has_new_domain_support(struct rpi_power_domains *rpi_domains)
{
	struct rpi_power_domain_packet packet;
	int ret;

	packet.domain = RPI_POWER_DOMAIN_ARM;
	packet.on = ~0;

	ret = rpi_firmware_property(rpi_domains->fw,
				    RPI_FIRMWARE_GET_DOMAIN_STATE,
				    &packet, sizeof(packet));

	return ret == 0 && packet.on != ~0;
}

static int rpi_power_probe(struct platform_device *pdev)
{
	struct device_node *fw_np;
	struct device *dev = &pdev->dev;
	struct rpi_power_domains *rpi_domains;

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

	rpi_domains->xlate.domains =
		devm_kcalloc(dev,
			     RPI_POWER_DOMAIN_COUNT,
			     sizeof(*rpi_domains->xlate.domains),
			     GFP_KERNEL);
	if (!rpi_domains->xlate.domains)
		return -ENOMEM;

	rpi_domains->xlate.num_domains = RPI_POWER_DOMAIN_COUNT;

	fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
	if (!fw_np) {
		dev_err(&pdev->dev, "no firmware node\n");
		return -ENODEV;
	}

	rpi_domains->fw = rpi_firmware_get(fw_np);
	of_node_put(fw_np);
	if (!rpi_domains->fw)
		return -EPROBE_DEFER;

	rpi_domains->has_new_interface =
		rpi_has_new_domain_support(rpi_domains);

	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C0, "I2C0");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C1, "I2C1");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C2, "I2C2");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VIDEO_SCALER,
			      "VIDEO_SCALER");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VPU1, "VPU1");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_HDMI, "HDMI");

	/*
	 * Use the old firmware interface for USB power, so that we
	 * can turn it on even if the firmware hasn't been updated.
	 */
	rpi_init_old_power_domain(rpi_domains, RPI_POWER_DOMAIN_USB,
				  RPI_OLD_POWER_DOMAIN_USB, "USB");

	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VEC, "VEC");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_JPEG, "JPEG");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_H264, "H264");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_V3D, "V3D");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ISP, "ISP");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM0, "UNICAM0");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM1, "UNICAM1");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2RX, "CCP2RX");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CSI2, "CSI2");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CPI, "CPI");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI0, "DSI0");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI1, "DSI1");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_TRANSPOSER,
			      "TRANSPOSER");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2TX, "CCP2TX");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CDP, "CDP");
	rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ARM, "ARM");

	of_genpd_add_provider_onecell(dev->of_node, &rpi_domains->xlate);

	platform_set_drvdata(pdev, rpi_domains);

	return 0;
}

static const struct of_device_id rpi_power_of_match[] = {
	{ .compatible = "raspberrypi,bcm2835-power", },
	{},
};
MODULE_DEVICE_TABLE(of, rpi_power_of_match);

static struct platform_driver rpi_power_driver = {
	.driver = {
		.name = "raspberrypi-power",
		.of_match_table = rpi_power_of_match,
	},
	.probe		= rpi_power_probe,
};
builtin_platform_driver(rpi_power_driver);

MODULE_AUTHOR("Alexander Aring <aar@pengutronix.de>");
MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
MODULE_DESCRIPTION("Raspberry Pi power domain driver");
MODULE_LICENSE("GPL v2");