--- /dev/null
+/* (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Authors:
+ * Alexander Aring <aar@pengutronix.de>
+ * Eric Anholt <eric@anholt.net>
+ */
+
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <dt-bindings/power/raspberrypi-power.h>
+#include <soc/bcm2835/raspberrypi-firmware.h>
+
+/*
+ * Firmware indices for the old power domains interface. Only a few
+ * of them were actually implemented.
+ */
+#define RPI_OLD_POWER_DOMAIN_USB 3
+#define RPI_OLD_POWER_DOMAIN_V3D 10
+
+struct rpi_power_domain {
+ u32 domain;
+ bool enabled;
+ bool old_interface;
+ struct generic_pm_domain base;
+ struct rpi_firmware *fw;
+};
+
+struct rpi_power_domains {
+ bool has_new_interface;
+ struct genpd_onecell_data xlate;
+ struct rpi_firmware *fw;
+ struct rpi_power_domain domains[RPI_POWER_DOMAIN_COUNT];
+};
+
+/*
+ * Packet definition used by RPI_FIRMWARE_SET_POWER_STATE and
+ * RPI_FIRMWARE_SET_DOMAIN_STATE
+ */
+struct rpi_power_domain_packet {
+ u32 domain;
+ u32 on;
+} __packet;
+
+/*
+ * Asks the firmware to enable or disable power on a specific power
+ * domain.
+ */
+static int rpi_firmware_set_power(struct rpi_power_domain *rpi_domain, bool on)
+{
+ struct rpi_power_domain_packet packet;
+
+ packet.domain = rpi_domain->domain;
+ packet.on = on;
+ return rpi_firmware_property(rpi_domain->fw,
+ rpi_domain->old_interface ?
+ RPI_FIRMWARE_SET_POWER_STATE :
+ RPI_FIRMWARE_SET_DOMAIN_STATE,
+ &packet, sizeof(packet));
+}
+
+static int rpi_domain_off(struct generic_pm_domain *domain)
+{
+ struct rpi_power_domain *rpi_domain =
+ container_of(domain, struct rpi_power_domain, base);
+
+ return rpi_firmware_set_power(rpi_domain, false);
+}
+
+static int rpi_domain_on(struct generic_pm_domain *domain)
+{
+ struct rpi_power_domain *rpi_domain =
+ container_of(domain, struct rpi_power_domain, base);
+
+ return rpi_firmware_set_power(rpi_domain, true);
+}
+
+static void rpi_common_init_power_domain(struct rpi_power_domains *rpi_domains,
+ int xlate_index, const char *name)
+{
+ struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
+
+ dom->fw = rpi_domains->fw;
+
+ dom->base.name = name;
+ dom->base.power_on = rpi_domain_on;
+ dom->base.power_off = rpi_domain_off;
+
+ /*
+ * Treat all power domains as off at boot.
+ *
+ * The firmware itself may be keeping some domains on, but
+ * from Linux's perspective all we control is the refcounts
+ * that we give to the firmware, and we can't ask the firmware
+ * to turn off something that we haven't ourselves turned on.
+ */
+ pm_genpd_init(&dom->base, NULL, true);
+
+ rpi_domains->xlate.domains[xlate_index] = &dom->base;
+}
+
+static void rpi_init_power_domain(struct rpi_power_domains *rpi_domains,
+ int xlate_index, const char *name)
+{
+ struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
+
+ if (!rpi_domains->has_new_interface)
+ return;
+
+ /* The DT binding index is the firmware's domain index minus one. */
+ dom->domain = xlate_index + 1;
+
+ rpi_common_init_power_domain(rpi_domains, xlate_index, name);
+}
+
+static void rpi_init_old_power_domain(struct rpi_power_domains *rpi_domains,
+ int xlate_index, int domain,
+ const char *name)
+{
+ struct rpi_power_domain *dom = &rpi_domains->domains[xlate_index];
+
+ dom->old_interface = true;
+ dom->domain = domain;
+
+ rpi_common_init_power_domain(rpi_domains, xlate_index, name);
+}
+
+/*
+ * Detects whether the firmware supports the new power domains interface.
+ *
+ * The firmware doesn't actually return an error on an unknown tag,
+ * and just skips over it, so we do the detection by putting an
+ * unexpected value in the return field and checking if it was
+ * unchanged.
+ */
+static bool
+rpi_has_new_domain_support(struct rpi_power_domains *rpi_domains)
+{
+ struct rpi_power_domain_packet packet;
+ int ret;
+
+ packet.domain = RPI_POWER_DOMAIN_ARM;
+ packet.on = ~0;
+
+ ret = rpi_firmware_property(rpi_domains->fw,
+ RPI_FIRMWARE_GET_DOMAIN_STATE,
+ &packet, sizeof(packet));
+
+ return ret == 0 && packet.on != ~0;
+}
+
+static int rpi_power_probe(struct platform_device *pdev)
+{
+ struct device_node *fw_np;
+ struct device *dev = &pdev->dev;
+ struct rpi_power_domains *rpi_domains;
+
+ rpi_domains = devm_kzalloc(dev, sizeof(*rpi_domains), GFP_KERNEL);
+ if (!rpi_domains)
+ return -ENOMEM;
+
+ rpi_domains->xlate.domains =
+ devm_kzalloc(dev, sizeof(*rpi_domains->xlate.domains) *
+ RPI_POWER_DOMAIN_COUNT, GFP_KERNEL);
+ if (!rpi_domains->xlate.domains)
+ return -ENOMEM;
+
+ rpi_domains->xlate.num_domains = RPI_POWER_DOMAIN_COUNT;
+
+ fw_np = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
+ if (!fw_np) {
+ dev_err(&pdev->dev, "no firmware node\n");
+ return -ENODEV;
+ }
+
+ rpi_domains->fw = rpi_firmware_get(fw_np);
+ of_node_put(fw_np);
+ if (!rpi_domains->fw)
+ return -EPROBE_DEFER;
+
+ rpi_domains->has_new_interface =
+ rpi_has_new_domain_support(rpi_domains);
+
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C0, "I2C0");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C1, "I2C1");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_I2C2, "I2C2");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VIDEO_SCALER,
+ "VIDEO_SCALER");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VPU1, "VPU1");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_HDMI, "HDMI");
+
+ /*
+ * Use the old firmware interface for USB power, so that we
+ * can turn it on even if the firmware hasn't been updated.
+ */
+ rpi_init_old_power_domain(rpi_domains, RPI_POWER_DOMAIN_USB,
+ RPI_OLD_POWER_DOMAIN_USB, "USB");
+
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_VEC, "VEC");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_JPEG, "JPEG");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_H264, "H264");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_V3D, "V3D");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ISP, "ISP");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM0, "UNICAM0");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_UNICAM1, "UNICAM1");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2RX, "CCP2RX");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CSI2, "CSI2");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CPI, "CPI");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI0, "DSI0");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_DSI1, "DSI1");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_TRANSPOSER,
+ "TRANSPOSER");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CCP2TX, "CCP2TX");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_CDP, "CDP");
+ rpi_init_power_domain(rpi_domains, RPI_POWER_DOMAIN_ARM, "ARM");
+
+ of_genpd_add_provider_onecell(dev->of_node, &rpi_domains->xlate);
+
+ platform_set_drvdata(pdev, rpi_domains);
+
+ return 0;
+}
+
+static const struct of_device_id rpi_power_of_match[] = {
+ { .compatible = "raspberrypi,bcm2835-power", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, rpi_power_of_match);
+
+static struct platform_driver rpi_power_driver = {
+ .driver = {
+ .name = "raspberrypi-power",
+ .of_match_table = rpi_power_of_match,
+ },
+ .probe = rpi_power_probe,
+};
+builtin_platform_driver(rpi_power_driver);
+
+MODULE_AUTHOR("Alexander Aring <aar@pengutronix.de>");
+MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
+MODULE_DESCRIPTION("Raspberry Pi power domain driver");
+MODULE_LICENSE("GPL v2");
projects / users / dwmw2 / linux.git / commitdiff