1 // SPDX-License-Identifier: GPL-2.0
2 /* (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
3 *
4 * Authors:
5 * Alexander Aring <aar@pengutronix.de>
6 * Eric Anholt <eric@anholt.net>
7 */
8
9 #include <linux/module.h>
10 #include <linux/of_platform.h>
11 #include <linux/platform_device.h>
12 #include <linux/pm_domain.h>
13 #include <dt-bindings/power/raspberrypi-power.h>
14 #include <soc/bcm2835/raspberrypi-firmware.h>
15
16 /*
17 * Firmware indices for the old power domains interface. Only a few
18 * of them were actually implemented.
19 */
20 #define RPI_OLD_POWER_DOMAIN_USB 3
21 #define RPI_OLD_POWER_DOMAIN_V3D 10
22
23 struct rpi_power_domain {
24 u32 domain;
25 bool enabled;
26 bool old_interface;
27 struct generic_pm_domain base;
28 struct rpi_firmware *fw;
29 };
30
31 struct rpi_power_domains {
32 bool has_new_interface;
33 struct genpd_onecell_data xlate;
34 struct rpi_firmware *fw;
35 struct rpi_power_domain domains[RPI_POWER_DOMAIN_COUNT];
36 };
37
38 /*
39 * Packet definition used by RPI_FIRMWARE_SET_POWER_STATE and
40 * RPI_FIRMWARE_SET_DOMAIN_STATE
41 */
42 struct rpi_power_domain_packet {
43 u32 domain;
44 u32 on;
45 };
46
47 /*
48 * Asks the firmware to enable or disable power on a specific power
49 * domain.
50 */
rpi_firmware_set_power(struct rpi_power_domain * rpi_domain,bool on)51 static int rpi_firmware_set_power(struct rpi_power_domain *rpi_domain, bool on)
52 {
53 struct rpi_power_domain_packet packet;
54
55 packet.domain = rpi_domain->domain;
56 packet.on = on;
57 return rpi_firmware_property(rpi_domain->fw,
58 rpi_domain->old_interface ?
59 RPI_FIRMWARE_SET_POWER_STATE :
60 RPI_FIRMWARE_SET_DOMAIN_STATE,
61 &packet, sizeof(packet));
62 }
63
rpi_domain_off(struct generic_pm_domain * domain)64 static int rpi_domain_off(struct generic_pm_domain *domain)
65 {
66 struct rpi_power_domain *rpi_domain =
67 container_of(domain, struct rpi_power_domain, base);
68
69 return rpi_firmware_set_power(rpi_domain, false);
70 }
71
rpi_domain_on(struct generic_pm_domain * domain)72 static int rpi_domain_on(struct generic_pm_domain *domain)
73 {
74 struct rpi_power_domain *rpi_domain =
75 container_of(domain, struct rpi_power_domain, base);
76
77 return rpi_firmware_set_power(rpi_domain, true);
78 }
79
rpi_common_init_power_domain(struct rpi_power_domains * rpi_domains,int xlate_index,const char * name)80 static void rpi_common_init_power_domain(struct rpi_power_domains *rpi_domains,
81 int xlate_index, const char *name)
82 {
83 struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
84
85 dom->fw = rpi_domains->fw;
86
87 dom->base.name = name;
88 dom->base.power_on = rpi_domain_on;
89 dom->base.power_off = rpi_domain_off;
90
91 /*
92 * Treat all power domains as off at boot.
93 *
94 * The firmware itself may be keeping some domains on, but
95 * from Linux's perspective all we control is the refcounts
96 * that we give to the firmware, and we can't ask the firmware
97 * to turn off something that we haven't ourselves turned on.
98 */
99 pm_genpd_init(&dom->base, NULL, true);
100
101 rpi_domains->xlate.domains[xlate_index] = &dom->base;
102 }
103
rpi_init_power_domain(struct rpi_power_domains * rpi_domains,int xlate_index,const char * name)104 static void rpi_init_power_domain(struct rpi_power_domains *rpi_domains,
105 int xlate_index, const char *name)
106 {
107 struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
108
109 if (!rpi_domains->has_new_interface)
110 return;
111
112 /* The DT binding index is the firmware's domain index minus one. */
113 dom->domain = xlate_index + 1;
114
115 rpi_common_init_power_domain(rpi_domains, xlate_index, name);
116 }
117
rpi_init_old_power_domain(struct rpi_power_domains * rpi_domains,int xlate_index,int domain,const char * name)118 static void rpi_init_old_power_domain(struct rpi_power_domains *rpi_domains,
119 int xlate_index, int domain,
120 const char *name)
121 {
122 struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
123
124 dom->old_interface = true;
125 dom->domain = domain;
126
127 rpi_common_init_power_domain(rpi_domains, xlate_index, name);
128 }
129
130 /*
131 * Detects whether the firmware supports the new power domains interface.
132 *
133 * The firmware doesn't actually return an error on an unknown tag,
134 * and just skips over it, so we do the detection by putting an
135 * unexpected value in the return field and checking if it was
136 * unchanged.
137 */
138 static bool
rpi_has_new_domain_support(struct rpi_power_domains * rpi_domains)139 rpi_has_new_domain_support(struct rpi_power_domains *rpi_domains)
140 {
141 struct rpi_power_domain_packet packet;
142 int ret;
143
144 packet.domain = RPI_POWER_DOMAIN_ARM;
145 packet.on = ~0;
146
147 ret = rpi_firmware_property(rpi_domains->fw,
148 RPI_FIRMWARE_GET_DOMAIN_STATE,
149 &packet, sizeof(packet));
150
151 return ret == 0 && packet.on != ~0;
152 }
153
rpi_power_probe(struct platform_device * pdev)154 static int rpi_power_probe(struct platform_device *pdev)
155 {
156 struct device_node *fw_np;
157 struct device *dev = &pdev->dev;
158 struct rpi_power_domains *rpi_domains;
159
160 rpi_domains = devm_kzalloc(dev, sizeof(*rpi_domains), GFP_KERNEL);
161 if (!rpi_domains)
162 return -ENOMEM;
163
164 rpi_domains->xlate.domains =
165 devm_kcalloc(dev,
166 RPI_POWER_DOMAIN_COUNT,
167 sizeof(*rpi_domains->xlate.domains),
168 GFP_KERNEL);
169 if (!rpi_domains->xlate.domains)
170 return -ENOMEM;
171
172 rpi_domains->xlate.num_domains = RPI_POWER_DOMAIN_COUNT;
173
174 fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
175 if (!fw_np) {
176 dev_err(&pdev->dev, "no firmware node\n");
177 return -ENODEV;
178 }
179
180 rpi_domains->fw = rpi_firmware_get(fw_np);
181 of_node_put(fw_np);
182 if (!rpi_domains->fw)
183 return -EPROBE_DEFER;
184
185 rpi_domains->has_new_interface =
186 rpi_has_new_domain_support(rpi_domains);
187
188 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C0, "I2C0");
189 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C1, "I2C1");
190 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C2, "I2C2");
191 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VIDEO_SCALER,
192 "VIDEO_SCALER");
193 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VPU1, "VPU1");
194 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_HDMI, "HDMI");
195
196 /*
197 * Use the old firmware interface for USB power, so that we
198 * can turn it on even if the firmware hasn't been updated.
199 */
200 rpi_init_old_power_domain(rpi_domains, RPI_POWER_DOMAIN_USB,
201 RPI_OLD_POWER_DOMAIN_USB, "USB");
202
203 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VEC, "VEC");
204 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_JPEG, "JPEG");
205 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_H264, "H264");
206 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_V3D, "V3D");
207 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ISP, "ISP");
208 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM0, "UNICAM0");
209 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM1, "UNICAM1");
210 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2RX, "CCP2RX");
211 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CSI2, "CSI2");
212 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CPI, "CPI");
213 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI0, "DSI0");
214 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI1, "DSI1");
215 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_TRANSPOSER,
216 "TRANSPOSER");
217 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2TX, "CCP2TX");
218 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CDP, "CDP");
219 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ARM, "ARM");
220
221 of_genpd_add_provider_onecell(dev->of_node, &rpi_domains->xlate);
222
223 platform_set_drvdata(pdev, rpi_domains);
224
225 return 0;
226 }
227
228 static const struct of_device_id rpi_power_of_match[] = {
229 { .compatible = "raspberrypi,bcm2835-power", },
230 {},
231 };
232 MODULE_DEVICE_TABLE(of, rpi_power_of_match);
233
234 static struct platform_driver rpi_power_driver = {
235 .driver = {
236 .name = "raspberrypi-power",
237 .of_match_table = rpi_power_of_match,
238 },
239 .probe = rpi_power_probe,
240 };
241 builtin_platform_driver(rpi_power_driver);
242
243 MODULE_AUTHOR("Alexander Aring <aar@pengutronix.de>");
244 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
245 MODULE_DESCRIPTION("Raspberry Pi power domain driver");
246 MODULE_LICENSE("GPL v2");
247