soc/bcm/raspberrypi-power.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /* (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
0003  *
0004  * Authors:
0005  * Alexander Aring <aar@pengutronix.de>
0006  * Eric Anholt <eric@anholt.net>
0007  */
0008
0009 #include <linux/module.h>
0010 #include <linux/of_platform.h>
0011 #include <linux/platform_device.h>
0012 #include <linux/pm_domain.h>
0013 #include <dt-bindings/power/raspberrypi-power.h>
0014 #include <soc/bcm2835/raspberrypi-firmware.h>
0015
0016 /*
0017  * Firmware indices for the old power domains interface.  Only a few
0018  * of them were actually implemented.
0019  */
0020 #define RPI_OLD_POWER_DOMAIN_USB        3
0021 #define RPI_OLD_POWER_DOMAIN_V3D        10
0022
0023 struct rpi_power_domain {
0024     u32 domain;
0025     bool enabled;
0026     bool old_interface;
0027     struct generic_pm_domain base;
0028     struct rpi_firmware *fw;
0029 };
0030
0031 struct rpi_power_domains {
0032     bool has_new_interface;
0033     struct genpd_onecell_data xlate;
0034     struct rpi_firmware *fw;
0035     struct rpi_power_domain domains[RPI_POWER_DOMAIN_COUNT];
0036 };
0037
0038 /*
0039  * Packet definition used by RPI_FIRMWARE_SET_POWER_STATE and
0040  * RPI_FIRMWARE_SET_DOMAIN_STATE
0041  */
0042 struct rpi_power_domain_packet {
0043     u32 domain;
0044     u32 on;
0045 };
0046
0047 /*
0048  * Asks the firmware to enable or disable power on a specific power
0049  * domain.
0050  */
0051 static int rpi_firmware_set_power(struct rpi_power_domain *rpi_domain, bool on)
0052 {
0053     struct rpi_power_domain_packet packet;
0054
0055     packet.domain = rpi_domain->domain;
0056     packet.on = on;
0057     return rpi_firmware_property(rpi_domain->fw,
0058                      rpi_domain->old_interface ?
0059                      RPI_FIRMWARE_SET_POWER_STATE :
0060                      RPI_FIRMWARE_SET_DOMAIN_STATE,
0061                      &packet, sizeof(packet));
0062 }
0063
0064 static int rpi_domain_off(struct generic_pm_domain *domain)
0065 {
0066     struct rpi_power_domain *rpi_domain =
0067         container_of(domain, struct rpi_power_domain, base);
0068
0069     return rpi_firmware_set_power(rpi_domain, false);
0070 }
0071
0072 static int rpi_domain_on(struct generic_pm_domain *domain)
0073 {
0074     struct rpi_power_domain *rpi_domain =
0075         container_of(domain, struct rpi_power_domain, base);
0076
0077     return rpi_firmware_set_power(rpi_domain, true);
0078 }
0079
0080 static void rpi_common_init_power_domain(struct rpi_power_domains *rpi_domains,
0081                      int xlate_index, const char *name)
0082 {
0083     struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
0084
0085     dom->fw = rpi_domains->fw;
0086
0087     dom->base.name = name;
0088     dom->base.power_on = rpi_domain_on;
0089     dom->base.power_off = rpi_domain_off;
0090
0091     /*
0092      * Treat all power domains as off at boot.
0093      *
0094      * The firmware itself may be keeping some domains on, but
0095      * from Linux's perspective all we control is the refcounts
0096      * that we give to the firmware, and we can't ask the firmware
0097      * to turn off something that we haven't ourselves turned on.
0098      */
0099     pm_genpd_init(&dom->base, NULL, true);
0100
0101     rpi_domains->xlate.domains[xlate_index] = &dom->base;
0102 }
0103
0104 static void rpi_init_power_domain(struct rpi_power_domains *rpi_domains,
0105                   int xlate_index, const char *name)
0106 {
0107     struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
0108
0109     if (!rpi_domains->has_new_interface)
0110         return;
0111
0112     /* The DT binding index is the firmware's domain index minus one. */
0113     dom->domain = xlate_index + 1;
0114
0115     rpi_common_init_power_domain(rpi_domains, xlate_index, name);
0116 }
0117
0118 static void rpi_init_old_power_domain(struct rpi_power_domains *rpi_domains,
0119                       int xlate_index, int domain,
0120                       const char *name)
0121 {
0122     struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
0123
0124     dom->old_interface = true;
0125     dom->domain = domain;
0126
0127     rpi_common_init_power_domain(rpi_domains, xlate_index, name);
0128 }
0129
0130 /*
0131  * Detects whether the firmware supports the new power domains interface.
0132  *
0133  * The firmware doesn't actually return an error on an unknown tag,
0134  * and just skips over it, so we do the detection by putting an
0135  * unexpected value in the return field and checking if it was
0136  * unchanged.
0137  */
0138 static bool
0139 rpi_has_new_domain_support(struct rpi_power_domains *rpi_domains)
0140 {
0141     struct rpi_power_domain_packet packet;
0142     int ret;
0143
0144     packet.domain = RPI_POWER_DOMAIN_ARM;
0145     packet.on = ~0;
0146
0147     ret = rpi_firmware_property(rpi_domains->fw,
0148                     RPI_FIRMWARE_GET_DOMAIN_STATE,
0149                     &packet, sizeof(packet));
0150
0151     return ret == 0 && packet.on != ~0;
0152 }
0153
0154 static int rpi_power_probe(struct platform_device *pdev)
0155 {
0156     struct device_node *fw_np;
0157     struct device *dev = &pdev->dev;
0158     struct rpi_power_domains *rpi_domains;
0159
0160     rpi_domains = devm_kzalloc(dev, sizeof(*rpi_domains), GFP_KERNEL);
0161     if (!rpi_domains)
0162         return -ENOMEM;
0163
0164     rpi_domains->xlate.domains =
0165         devm_kcalloc(dev,
0166                  RPI_POWER_DOMAIN_COUNT,
0167                  sizeof(*rpi_domains->xlate.domains),
0168                  GFP_KERNEL);
0169     if (!rpi_domains->xlate.domains)
0170         return -ENOMEM;
0171
0172     rpi_domains->xlate.num_domains = RPI_POWER_DOMAIN_COUNT;
0173
0174     fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
0175     if (!fw_np) {
0176         dev_err(&pdev->dev, "no firmware node\n");
0177         return -ENODEV;
0178     }
0179
0180     rpi_domains->fw = devm_rpi_firmware_get(&pdev->dev, fw_np);
0181     of_node_put(fw_np);
0182     if (!rpi_domains->fw)
0183         return -EPROBE_DEFER;
0184
0185     rpi_domains->has_new_interface =
0186         rpi_has_new_domain_support(rpi_domains);
0187
0188     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C0, "I2C0");
0189     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C1, "I2C1");
0190     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C2, "I2C2");
0191     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VIDEO_SCALER,
0192                   "VIDEO_SCALER");
0193     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VPU1, "VPU1");
0194     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_HDMI, "HDMI");
0195
0196     /*
0197      * Use the old firmware interface for USB power, so that we
0198      * can turn it on even if the firmware hasn't been updated.
0199      */
0200     rpi_init_old_power_domain(rpi_domains, RPI_POWER_DOMAIN_USB,
0201                   RPI_OLD_POWER_DOMAIN_USB, "USB");
0202
0203     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VEC, "VEC");
0204     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_JPEG, "JPEG");
0205     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_H264, "H264");
0206     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_V3D, "V3D");
0207     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ISP, "ISP");
0208     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM0, "UNICAM0");
0209     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM1, "UNICAM1");
0210     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2RX, "CCP2RX");
0211     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CSI2, "CSI2");
0212     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CPI, "CPI");
0213     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI0, "DSI0");
0214     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI1, "DSI1");
0215     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_TRANSPOSER,
0216                   "TRANSPOSER");
0217     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2TX, "CCP2TX");
0218     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CDP, "CDP");
0219     rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ARM, "ARM");
0220
0221     of_genpd_add_provider_onecell(dev->of_node, &rpi_domains->xlate);
0222
0223     platform_set_drvdata(pdev, rpi_domains);
0224
0225     return 0;
0226 }
0227
0228 static const struct of_device_id rpi_power_of_match[] = {
0229     { .compatible = "raspberrypi,bcm2835-power", },
0230     {},
0231 };
0232 MODULE_DEVICE_TABLE(of, rpi_power_of_match);
0233
0234 static struct platform_driver rpi_power_driver = {
0235     .driver = {
0236         .name = "raspberrypi-power",
0237         .of_match_table = rpi_power_of_match,
0238     },
0239     .probe      = rpi_power_probe,
0240 };
0241 builtin_platform_driver(rpi_power_driver);
0242
0243 MODULE_AUTHOR("Alexander Aring <aar@pengutronix.de>");
0244 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
0245 MODULE_DESCRIPTION("Raspberry Pi power domain driver");
0246 MODULE_LICENSE("GPL v2");