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 on; |
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 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(fw: rpi_domain->fw, |
58 | tag: rpi_domain->old_interface ? |
59 | RPI_FIRMWARE_SET_POWER_STATE : |
60 | RPI_FIRMWARE_SET_DOMAIN_STATE, |
61 | data: &packet, len: sizeof(packet)); |
62 | } |
63 | |
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, on: false); |
70 | } |
71 | |
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, on: true); |
78 | } |
79 | |
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(genpd: &dom->base, NULL, is_off: true); |
100 | |
101 | rpi_domains->xlate.domains[xlate_index] = &dom->base; |
102 | } |
103 | |
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 | |
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 |
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(fw: rpi_domains->fw, |
148 | tag: RPI_FIRMWARE_GET_DOMAIN_STATE, |
149 | data: &packet, len: sizeof(packet)); |
150 | |
151 | return ret == 0 && packet.on != ~0; |
152 | } |
153 | |
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, size: 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 | size: 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(np: pdev->dev.of_node, phandle_name: "firmware" , index: 0); |
175 | if (!fw_np) { |
176 | dev_err(&pdev->dev, "no firmware node\n" ); |
177 | return -ENODEV; |
178 | } |
179 | |
180 | rpi_domains->fw = devm_rpi_firmware_get(dev: &pdev->dev, firmware_node: fw_np); |
181 | of_node_put(node: 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, name: "I2C0" ); |
189 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C1, name: "I2C1" ); |
190 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C2, name: "I2C2" ); |
191 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VIDEO_SCALER, |
192 | name: "VIDEO_SCALER" ); |
193 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VPU1, name: "VPU1" ); |
194 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_HDMI, name: "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, name: "USB" ); |
202 | |
203 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VEC, name: "VEC" ); |
204 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_JPEG, name: "JPEG" ); |
205 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_H264, name: "H264" ); |
206 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_V3D, name: "V3D" ); |
207 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ISP, name: "ISP" ); |
208 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM0, name: "UNICAM0" ); |
209 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM1, name: "UNICAM1" ); |
210 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2RX, name: "CCP2RX" ); |
211 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CSI2, name: "CSI2" ); |
212 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CPI, name: "CPI" ); |
213 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI0, name: "DSI0" ); |
214 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI1, name: "DSI1" ); |
215 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_TRANSPOSER, |
216 | name: "TRANSPOSER" ); |
217 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2TX, name: "CCP2TX" ); |
218 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CDP, name: "CDP" ); |
219 | rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ARM, name: "ARM" ); |
220 | |
221 | of_genpd_add_provider_onecell(np: dev->of_node, data: &rpi_domains->xlate); |
222 | |
223 | platform_set_drvdata(pdev, data: 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 | |