root/drivers/soc/bcm/raspberrypi-power.c

DEFINITIONS

1. rpi_firmware_set_power
2. rpi_domain_off
3. rpi_domain_on
4. rpi_common_init_power_domain
5. rpi_init_power_domain
6. rpi_init_old_power_domain
7. rpi_has_new_domain_support
8. rpi_power_probe

   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_platform.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 = rpi_firmware_get(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 MODULE_LICENSE("GPL v2");