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