drivers/pmdomain/bcm/raspberrypi-power.c

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