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.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 state;
45 };
46
47 /*
48 * Asks the firmware to enable or disable power on a specific power
49 * domain.
50 */
rpi_firmware_set_power(struct generic_pm_domain * domain,bool on)51 static int rpi_firmware_set_power(struct generic_pm_domain *domain, bool on)
52 {
53 struct rpi_power_domain *rpi_domain =
54 container_of(domain, struct rpi_power_domain, base);
55 bool old_interface = rpi_domain->old_interface;
56 struct rpi_power_domain_packet packet;
57 int ret;
58
59 packet.domain = rpi_domain->domain;
60 packet.state = on;
61
62 ret = rpi_firmware_property(rpi_domain->fw, old_interface ?
63 RPI_FIRMWARE_SET_POWER_STATE :
64 RPI_FIRMWARE_SET_DOMAIN_STATE,
65 &packet, sizeof(packet));
66 if (ret)
67 dev_err(&domain->dev, "Failed to set %s to %u (%d)\n",
68 old_interface ? "power" : "domain", on, ret);
69 else
70 dev_dbg(&domain->dev, "Set %s to %u\n",
71 old_interface ? "power" : "domain", on);
72
73 return ret;
74 }
75
rpi_domain_off(struct generic_pm_domain * domain)76 static int rpi_domain_off(struct generic_pm_domain *domain)
77 {
78 return rpi_firmware_set_power(domain, false);
79 }
80
rpi_domain_on(struct generic_pm_domain * domain)81 static int rpi_domain_on(struct generic_pm_domain *domain)
82 {
83 return rpi_firmware_set_power(domain, true);
84 }
85
rpi_common_init_power_domain(struct rpi_power_domains * rpi_domains,int xlate_index,const char * name)86 static void rpi_common_init_power_domain(struct rpi_power_domains *rpi_domains,
87 int xlate_index, const char *name)
88 {
89 struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
90
91 dom->fw = rpi_domains->fw;
92
93 dom->base.name = name;
94 dom->base.flags = GENPD_FLAG_ACTIVE_WAKEUP;
95 dom->base.power_on = rpi_domain_on;
96 dom->base.power_off = rpi_domain_off;
97
98 /*
99 * Treat all power domains as off at boot.
100 *
101 * The firmware itself may be keeping some domains on, but
102 * from Linux's perspective all we control is the refcounts
103 * that we give to the firmware, and we can't ask the firmware
104 * to turn off something that we haven't ourselves turned on.
105 */
106 pm_genpd_init(&dom->base, NULL, true);
107
108 rpi_domains->xlate.domains[xlate_index] = &dom->base;
109 }
110
rpi_init_power_domain(struct rpi_power_domains * rpi_domains,int xlate_index,const char * name)111 static void rpi_init_power_domain(struct rpi_power_domains *rpi_domains,
112 int xlate_index, const char *name)
113 {
114 struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
115
116 if (!rpi_domains->has_new_interface)
117 return;
118
119 /* The DT binding index is the firmware's domain index minus one. */
120 dom->domain = xlate_index + 1;
121
122 rpi_common_init_power_domain(rpi_domains, xlate_index, name);
123 }
124
rpi_init_old_power_domain(struct rpi_power_domains * rpi_domains,int xlate_index,int domain,const char * name)125 static void rpi_init_old_power_domain(struct rpi_power_domains *rpi_domains,
126 int xlate_index, int domain,
127 const char *name)
128 {
129 struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
130
131 dom->old_interface = true;
132 dom->domain = domain;
133
134 rpi_common_init_power_domain(rpi_domains, xlate_index, name);
135 }
136
137 /*
138 * Detects whether the firmware supports the new power domains interface.
139 *
140 * The firmware doesn't actually return an error on an unknown tag,
141 * and just skips over it, so we do the detection by putting an
142 * unexpected value in the return field and checking if it was
143 * unchanged.
144 */
145 static bool
rpi_has_new_domain_support(struct rpi_power_domains * rpi_domains)146 rpi_has_new_domain_support(struct rpi_power_domains *rpi_domains)
147 {
148 struct rpi_power_domain_packet packet;
149 int ret;
150
151 packet.domain = RPI_POWER_DOMAIN_ARM;
152 packet.state = ~0;
153
154 ret = rpi_firmware_property(rpi_domains->fw,
155 RPI_FIRMWARE_GET_DOMAIN_STATE,
156 &packet, sizeof(packet));
157
158 return ret == 0 && packet.state != ~0;
159 }
160
rpi_power_probe(struct platform_device * pdev)161 static int rpi_power_probe(struct platform_device *pdev)
162 {
163 struct device_node *fw_np;
164 struct device *dev = &pdev->dev;
165 struct rpi_power_domains *rpi_domains;
166
167 rpi_domains = devm_kzalloc(dev, sizeof(*rpi_domains), GFP_KERNEL);
168 if (!rpi_domains)
169 return -ENOMEM;
170
171 rpi_domains->xlate.domains =
172 devm_kcalloc(dev,
173 RPI_POWER_DOMAIN_COUNT,
174 sizeof(*rpi_domains->xlate.domains),
175 GFP_KERNEL);
176 if (!rpi_domains->xlate.domains)
177 return -ENOMEM;
178
179 rpi_domains->xlate.num_domains = RPI_POWER_DOMAIN_COUNT;
180
181 fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
182 if (!fw_np) {
183 dev_err(&pdev->dev, "no firmware node\n");
184 return -ENODEV;
185 }
186
187 rpi_domains->fw = devm_rpi_firmware_get(&pdev->dev, fw_np);
188 of_node_put(fw_np);
189 if (!rpi_domains->fw)
190 return -EPROBE_DEFER;
191
192 rpi_domains->has_new_interface =
193 rpi_has_new_domain_support(rpi_domains);
194
195 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C0, "I2C0");
196 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C1, "I2C1");
197 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C2, "I2C2");
198 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VIDEO_SCALER,
199 "VIDEO_SCALER");
200 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VPU1, "VPU1");
201 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_HDMI, "HDMI");
202
203 /*
204 * Use the old firmware interface for USB power, so that we
205 * can turn it on even if the firmware hasn't been updated.
206 */
207 rpi_init_old_power_domain(rpi_domains, RPI_POWER_DOMAIN_USB,
208 RPI_OLD_POWER_DOMAIN_USB, "USB");
209
210 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VEC, "VEC");
211 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_JPEG, "JPEG");
212 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_H264, "H264");
213 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_V3D, "V3D");
214 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ISP, "ISP");
215 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM0, "UNICAM0");
216 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM1, "UNICAM1");
217 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2RX, "CCP2RX");
218 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CSI2, "CSI2");
219 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CPI, "CPI");
220 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI0, "DSI0");
221 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI1, "DSI1");
222 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_TRANSPOSER,
223 "TRANSPOSER");
224 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2TX, "CCP2TX");
225 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CDP, "CDP");
226 rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ARM, "ARM");
227
228 of_genpd_add_provider_onecell(dev->of_node, &rpi_domains->xlate);
229
230 platform_set_drvdata(pdev, rpi_domains);
231
232 return 0;
233 }
234
235 static const struct of_device_id rpi_power_of_match[] = {
236 { .compatible = "raspberrypi,bcm2835-power", },
237 {},
238 };
239 MODULE_DEVICE_TABLE(of, rpi_power_of_match);
240
241 static struct platform_driver rpi_power_driver = {
242 .driver = {
243 .name = "raspberrypi-power",
244 .of_match_table = rpi_power_of_match,
245 },
246 .probe = rpi_power_probe,
247 };
248 builtin_platform_driver(rpi_power_driver);
249
250 MODULE_AUTHOR("Alexander Aring <aar@pengutronix.de>");
251 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
252 MODULE_DESCRIPTION("Raspberry Pi power domain driver");
253