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[J-linux.git] / drivers / pmdomain / bcm / raspberrypi-power.c
1 // SPDX-License-Identifier: GPL-2.0
2 /* (C) 2015 Pengutronix, Alexander Aring <[email protected]>
3  *
4  * Authors:
5  * Alexander Aring <[email protected]>
6  * Eric Anholt <[email protected]>
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  */
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
76 static int rpi_domain_off(struct generic_pm_domain *domain)
77 {
78         return rpi_firmware_set_power(domain, false);
79 }
80
81 static int rpi_domain_on(struct generic_pm_domain *domain)
82 {
83         return rpi_firmware_set_power(domain, true);
84 }
85
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
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
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
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
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 <[email protected]>");
251 MODULE_AUTHOR("Eric Anholt <[email protected]>");
252 MODULE_DESCRIPTION("Raspberry Pi power domain driver");
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