tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
2 *
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License version 2 as
5 * published by the Free Software Foundation.
6 *
7 * Authors:
8 * Alexander Aring <aar@pengutronix.de>
9 * Eric Anholt <eric@anholt.net>
10 */
11
12#include <linux/module.h>
13#include <linux/of_platform.h>
14#include <linux/platform_device.h>
15#include <linux/pm_domain.h>
16#include <dt-bindings/power/raspberrypi-power.h>
17#include <soc/bcm2835/raspberrypi-firmware.h>
18
19/*
20 * Firmware indices for the old power domains interface. Only a few
21 * of them were actually implemented.
22 */
23#define RPI_OLD_POWER_DOMAIN_USB 3
24#define RPI_OLD_POWER_DOMAIN_V3D 10
25
26struct rpi_power_domain {
27 u32 domain;
28 bool enabled;
29 bool old_interface;
30 struct generic_pm_domain base;
31 struct rpi_firmware *fw;
32};
33
34struct rpi_power_domains {
35 bool has_new_interface;
36 struct genpd_onecell_data xlate;
37 struct rpi_firmware *fw;
38 struct rpi_power_domain domains[RPI_POWER_DOMAIN_COUNT];
39};
40
41/*
42 * Packet definition used by RPI_FIRMWARE_SET_POWER_STATE and
43 * RPI_FIRMWARE_SET_DOMAIN_STATE
44 */
45struct rpi_power_domain_packet {
46 u32 domain;
47 u32 on;
48} __packet;
49
50/*
51 * Asks the firmware to enable or disable power on a specific power
52 * domain.
53 */
54static int rpi_firmware_set_power(struct rpi_power_domain *rpi_domain, bool on)
55{
56 struct rpi_power_domain_packet packet;
57
58 packet.domain = rpi_domain->domain;
59 packet.on = on;
60 return rpi_firmware_property(rpi_domain->fw,
61 rpi_domain->old_interface ?
62 RPI_FIRMWARE_SET_POWER_STATE :
63 RPI_FIRMWARE_SET_DOMAIN_STATE,
64 &packet, sizeof(packet));
65}
66
67static int rpi_domain_off(struct generic_pm_domain *domain)
68{
69 struct rpi_power_domain *rpi_domain =
70 container_of(domain, struct rpi_power_domain, base);
71
72 return rpi_firmware_set_power(rpi_domain, false);
73}
74
75static int rpi_domain_on(struct generic_pm_domain *domain)
76{
77 struct rpi_power_domain *rpi_domain =
78 container_of(domain, struct rpi_power_domain, base);
79
80 return rpi_firmware_set_power(rpi_domain, true);
81}
82
83static void rpi_common_init_power_domain(struct rpi_power_domains *rpi_domains,
84 int xlate_index, const char *name)
85{
86 struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
87
88 dom->fw = rpi_domains->fw;
89
90 dom->base.name = name;
91 dom->base.power_on = rpi_domain_on;
92 dom->base.power_off = rpi_domain_off;
93
94 /*
95 * Treat all power domains as off at boot.
96 *
97 * The firmware itself may be keeping some domains on, but
98 * from Linux's perspective all we control is the refcounts
99 * that we give to the firmware, and we can't ask the firmware
100 * to turn off something that we haven't ourselves turned on.
101 */
102 pm_genpd_init(&dom->base, NULL, true);
103
104 rpi_domains->xlate.domains[xlate_index] = &dom->base;
105}
106
107static void rpi_init_power_domain(struct rpi_power_domains *rpi_domains,
108 int xlate_index, const char *name)
109{
110 struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
111
112 if (!rpi_domains->has_new_interface)
113 return;
114
115 /* The DT binding index is the firmware's domain index minus one. */
116 dom->domain = xlate_index + 1;
117
118 rpi_common_init_power_domain(rpi_domains, xlate_index, name);
119}
120
121static void rpi_init_old_power_domain(struct rpi_power_domains *rpi_domains,
122 int xlate_index, int domain,
123 const char *name)
124{
125 struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
126
127 dom->old_interface = true;
128 dom->domain = domain;
129
130 rpi_common_init_power_domain(rpi_domains, xlate_index, name);
131}
132
133/*
134 * Detects whether the firmware supports the new power domains interface.
135 *
136 * The firmware doesn't actually return an error on an unknown tag,
137 * and just skips over it, so we do the detection by putting an
138 * unexpected value in the return field and checking if it was
139 * unchanged.
140 */
141static bool
142rpi_has_new_domain_support(struct rpi_power_domains *rpi_domains)
143{
144 struct rpi_power_domain_packet packet;
145 int ret;
146
147 packet.domain = RPI_POWER_DOMAIN_ARM;
148 packet.on = ~0;
149
150 ret = rpi_firmware_property(rpi_domains->fw,
151 RPI_FIRMWARE_GET_DOMAIN_STATE,
152 &packet, sizeof(packet));
153
154 return ret == 0 && packet.on != ~0;
155}
156
157static int rpi_power_probe(struct platform_device *pdev)
158{
159 struct device_node *fw_np;
160 struct device *dev = &pdev->dev;
161 struct rpi_power_domains *rpi_domains;
162
163 rpi_domains = devm_kzalloc(dev, sizeof(*rpi_domains), GFP_KERNEL);
164 if (!rpi_domains)
165 return -ENOMEM;
166
167 rpi_domains->xlate.domains =
168 devm_kzalloc(dev, sizeof(*rpi_domains->xlate.domains) *
169 RPI_POWER_DOMAIN_COUNT, GFP_KERNEL);
170 if (!rpi_domains->xlate.domains)
171 return -ENOMEM;
172
173 rpi_domains->xlate.num_domains = RPI_POWER_DOMAIN_COUNT;
174
175 fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
176 if (!fw_np) {
177 dev_err(&pdev->dev, "no firmware node\n");
178 return -ENODEV;
179 }
180
181 rpi_domains->fw = rpi_firmware_get(fw_np);
182 of_node_put(fw_np);
183 if (!rpi_domains->fw)
184 return -EPROBE_DEFER;
185
186 rpi_domains->has_new_interface =
187 rpi_has_new_domain_support(rpi_domains);
188
189 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C0, "I2C0");
190 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C1, "I2C1");
191 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C2, "I2C2");
192 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VIDEO_SCALER,
193 "VIDEO_SCALER");
194 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VPU1, "VPU1");
195 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_HDMI, "HDMI");
196
197 /*
198 * Use the old firmware interface for USB power, so that we
199 * can turn it on even if the firmware hasn't been updated.
200 */
201 rpi_init_old_power_domain(rpi_domains, RPI_POWER_DOMAIN_USB,
202 RPI_OLD_POWER_DOMAIN_USB, "USB");
203
204 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VEC, "VEC");
205 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_JPEG, "JPEG");
206 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_H264, "H264");
207 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_V3D, "V3D");
208 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ISP, "ISP");
209 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM0, "UNICAM0");
210 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM1, "UNICAM1");
211 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2RX, "CCP2RX");
212 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CSI2, "CSI2");
213 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CPI, "CPI");
214 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI0, "DSI0");
215 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI1, "DSI1");
216 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_TRANSPOSER,
217 "TRANSPOSER");
218 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2TX, "CCP2TX");
219 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CDP, "CDP");
220 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ARM, "ARM");
221
222 of_genpd_add_provider_onecell(dev->of_node, &rpi_domains->xlate);
223
224 platform_set_drvdata(pdev, rpi_domains);
225
226 return 0;
227}
228
229static const struct of_device_id rpi_power_of_match[] = {
230 { .compatible = "raspberrypi,bcm2835-power", },
231 {},
232};
233MODULE_DEVICE_TABLE(of, rpi_power_of_match);
234
235static struct platform_driver rpi_power_driver = {
236 .driver = {
237 .name = "raspberrypi-power",
238 .of_match_table = rpi_power_of_match,
239 },
240 .probe = rpi_power_probe,
241};
242builtin_platform_driver(rpi_power_driver);
243
244MODULE_AUTHOR("Alexander Aring <aar@pengutronix.de>");
245MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
246MODULE_DESCRIPTION("Raspberry Pi power domain driver");
247MODULE_LICENSE("GPL v2");