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(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 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 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 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 } 103 104 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(rpi_domains->fw, 148 RPI_FIRMWARE_GET_DOMAIN_STATE, 149 &packet, 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, 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 = devm_rpi_firmware_get(&pdev->dev, 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