drivers/soc/bcm/raspberrypi-power.c

   1 /* (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License version 2 as
   5  * published by the Free Software Foundation.
   6  *
   7  * Authors:
   8  * Alexander Aring <aar@pengutronix.de>
   9  * Eric Anholt <eric@anholt.net>
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/of_platform.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/pm_domain.h>
  16 #include <dt-bindings/power/raspberrypi-power.h>
  17 #include <soc/bcm2835/raspberrypi-firmware.h>
  18
  19 /*
  20  * Firmware indices for the old power domains interface.  Only a few
  21  * of them were actually implemented.
  22  */
  23 #define RPI_OLD_POWER_DOMAIN_USB                3
  24 #define RPI_OLD_POWER_DOMAIN_V3D                10
  25
  26 struct rpi_power_domain {
  27         u32 domain;
  28         bool enabled;
  29         bool old_interface;
  30         struct generic_pm_domain base;
  31         struct rpi_firmware *fw;
  32 };
  33
  34 struct rpi_power_domains {
  35         bool has_new_interface;
  36         struct genpd_onecell_data xlate;
  37         struct rpi_firmware *fw;
  38         struct rpi_power_domain domains[RPI_POWER_DOMAIN_COUNT];
  39 };
  40
  41 /*
  42  * Packet definition used by RPI_FIRMWARE_SET_POWER_STATE and
  43  * RPI_FIRMWARE_SET_DOMAIN_STATE
  44  */
  45 struct rpi_power_domain_packet {
  46         u32 domain;
  47         u32 on;
  48 } __packet;
  49
  50 /*
  51  * Asks the firmware to enable or disable power on a specific power
  52  * domain.
  53  */
  54 static int rpi_firmware_set_power(struct rpi_power_domain *rpi_domain, bool on)
  55 {
  56         struct rpi_power_domain_packet packet;
  57
  58         packet.domain = rpi_domain->domain;
  59         packet.on = on;
  60         return rpi_firmware_property(rpi_domain->fw,
  61                                      rpi_domain->old_interface ?
  62                                      RPI_FIRMWARE_SET_POWER_STATE :
  63                                      RPI_FIRMWARE_SET_DOMAIN_STATE,
  64                                      &packet, sizeof(packet));
  65 }
  66
  67 static int rpi_domain_off(struct generic_pm_domain *domain)
  68 {
  69         struct rpi_power_domain *rpi_domain =
  70                 container_of(domain, struct rpi_power_domain, base);
  71
  72         return rpi_firmware_set_power(rpi_domain, false);
  73 }
  74
  75 static int rpi_domain_on(struct generic_pm_domain *domain)
  76 {
  77         struct rpi_power_domain *rpi_domain =
  78                 container_of(domain, struct rpi_power_domain, base);
  79
  80         return rpi_firmware_set_power(rpi_domain, true);
  81 }
  82
  83 static void rpi_common_init_power_domain(struct rpi_power_domains *rpi_domains,
  84                                          int xlate_index, const char *name)
  85 {
  86         struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
  87
  88         dom->fw = rpi_domains->fw;
  89
  90         dom->base.name = name;
  91         dom->base.power_on = rpi_domain_on;
  92         dom->base.power_off = rpi_domain_off;
  93
  94         /*
  95          * Treat all power domains as off at boot.
  96          *
  97          * The firmware itself may be keeping some domains on, but
  98          * from Linux's perspective all we control is the refcounts
  99          * that we give to the firmware, and we can't ask the firmware
 100          * to turn off something that we haven't ourselves turned on.
 101          */
 102         pm_genpd_init(&dom->base, NULL, true);
 103
 104         rpi_domains->xlate.domains[xlate_index] = &dom->base;
 105 }
 106
 107 static void rpi_init_power_domain(struct rpi_power_domains *rpi_domains,
 108                                   int xlate_index, const char *name)
 109 {
 110         struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
 111
 112         if (!rpi_domains->has_new_interface)
 113                 return;
 114
 115         /* The DT binding index is the firmware's domain index minus one. */
 116         dom->domain = xlate_index + 1;
 117
 118         rpi_common_init_power_domain(rpi_domains, xlate_index, name);
 119 }
 120
 121 static void rpi_init_old_power_domain(struct rpi_power_domains *rpi_domains,
 122                                       int xlate_index, int domain,
 123                                       const char *name)
 124 {
 125         struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
 126
 127         dom->old_interface = true;
 128         dom->domain = domain;
 129
 130         rpi_common_init_power_domain(rpi_domains, xlate_index, name);
 131 }
 132
 133 /*
 134  * Detects whether the firmware supports the new power domains interface.
 135  *
 136  * The firmware doesn't actually return an error on an unknown tag,
 137  * and just skips over it, so we do the detection by putting an
 138  * unexpected value in the return field and checking if it was
 139  * unchanged.
 140  */
 141 static bool
 142 rpi_has_new_domain_support(struct rpi_power_domains *rpi_domains)
 143 {
 144         struct rpi_power_domain_packet packet;
 145         int ret;
 146
 147         packet.domain = RPI_POWER_DOMAIN_ARM;
 148         packet.on = ~0;
 149
 150         ret = rpi_firmware_property(rpi_domains->fw,
 151                                     RPI_FIRMWARE_GET_DOMAIN_STATE,
 152                                     &packet, sizeof(packet));
 153
 154         return ret == 0 && packet.on != ~0;
 155 }
 156
 157 static int rpi_power_probe(struct platform_device *pdev)
 158 {
 159         struct device_node *fw_np;
 160         struct device *dev = &pdev->dev;
 161         struct rpi_power_domains *rpi_domains;
 162
 163         rpi_domains = devm_kzalloc(dev, sizeof(*rpi_domains), GFP_KERNEL);
 164         if (!rpi_domains)
 165                 return -ENOMEM;
 166
 167         rpi_domains->xlate.domains =
 168                 devm_kzalloc(dev, sizeof(*rpi_domains->xlate.domains) *
 169                              RPI_POWER_DOMAIN_COUNT, GFP_KERNEL);
 170         if (!rpi_domains->xlate.domains)
 171                 return -ENOMEM;
 172
 173         rpi_domains->xlate.num_domains = RPI_POWER_DOMAIN_COUNT;
 174
 175         fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
 176         if (!fw_np) {
 177                 dev_err(&pdev->dev, "no firmware node\n");
 178                 return -ENODEV;
 179         }
 180
 181         rpi_domains->fw = rpi_firmware_get(fw_np);
 182         of_node_put(fw_np);
 183         if (!rpi_domains->fw)
 184                 return -EPROBE_DEFER;
 185
 186         rpi_domains->has_new_interface =
 187                 rpi_has_new_domain_support(rpi_domains);
 188
 189         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C0, "I2C0");
 190         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C1, "I2C1");
 191         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C2, "I2C2");
 192         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VIDEO_SCALER,
 193                               "VIDEO_SCALER");
 194         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VPU1, "VPU1");
 195         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_HDMI, "HDMI");
 196
 197         /*
 198          * Use the old firmware interface for USB power, so that we
 199          * can turn it on even if the firmware hasn't been updated.
 200          */
 201         rpi_init_old_power_domain(rpi_domains, RPI_POWER_DOMAIN_USB,
 202                                   RPI_OLD_POWER_DOMAIN_USB, "USB");
 203
 204         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VEC, "VEC");
 205         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_JPEG, "JPEG");
 206         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_H264, "H264");
 207         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_V3D, "V3D");
 208         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ISP, "ISP");
 209         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM0, "UNICAM0");
 210         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM1, "UNICAM1");
 211         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2RX, "CCP2RX");
 212         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CSI2, "CSI2");
 213         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CPI, "CPI");
 214         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI0, "DSI0");
 215         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI1, "DSI1");
 216         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_TRANSPOSER,
 217                               "TRANSPOSER");
 218         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2TX, "CCP2TX");
 219         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CDP, "CDP");
 220         rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ARM, "ARM");
 221
 222         of_genpd_add_provider_onecell(dev->of_node, &rpi_domains->xlate);
 223
 224         platform_set_drvdata(pdev, rpi_domains);
 225
 226         return 0;
 227 }
 228
 229 static const struct of_device_id rpi_power_of_match[] = {
 230         { .compatible = "raspberrypi,bcm2835-power", },
 231         {},
 232 };
 233 MODULE_DEVICE_TABLE(of, rpi_power_of_match);
 234
 235 static struct platform_driver rpi_power_driver = {
 236         .driver = {
 237                 .name = "raspberrypi-power",
 238                 .of_match_table = rpi_power_of_match,
 239         },
 240         .probe          = rpi_power_probe,
 241 };
 242 builtin_platform_driver(rpi_power_driver);
 243
 244 MODULE_AUTHOR("Alexander Aring <aar@pengutronix.de>");
 245 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
 246 MODULE_DESCRIPTION("Raspberry Pi power domain driver");
 247 MODULE_LICENSE("GPL v2");