domains). This may be used to save power. This API provides the
means to control such power management hardware.
+config APPLE_PMGR_POWER_DOMAIN
+ bool "Enable the Apple PMGR power domain driver"
+ depends on POWER_DOMAIN
+ default y if ARCH_APPLE
+ help
+ Enable support for manipulating power domains on Apple SoCs.
+ This driver is needed to power on parts of the SoC that have
+ not been powered on by previous boot stages.
+
config BCM6328_POWER_DOMAIN
bool "Enable the BCM6328 power domain driver"
depends on POWER_DOMAIN && ARCH_BMIPS
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2021 Mark Kettenis <kettenis@openbsd.org>
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <dm.h>
+#include <linux/err.h>
+#include <linux/bitfield.h>
+#include <power-domain-uclass.h>
+#include <regmap.h>
+#include <syscon.h>
+
+#define APPLE_PMGR_PS_TARGET GENMASK(3, 0)
+#define APPLE_PMGR_PS_ACTUAL GENMASK(7, 4)
+
+#define APPLE_PMGR_PS_ACTIVE 0xf
+#define APPLE_PMGR_PS_PWRGATE 0x0
+
+#define APPLE_PMGR_PS_SET_TIMEOUT_US 100
+
+struct apple_pmgr_priv {
+ struct regmap *regmap;
+ u32 offset; /* offset within regmap for this domain */
+};
+
+static int apple_pmgr_request(struct power_domain *power_domain)
+{
+ return 0;
+}
+
+static int apple_pmgr_rfree(struct power_domain *power_domain)
+{
+ return 0;
+}
+
+static int apple_pmgr_ps_set(struct power_domain *power_domain, u32 pstate)
+{
+ struct apple_pmgr_priv *priv = dev_get_priv(power_domain->dev);
+ uint reg;
+
+ regmap_update_bits(priv->regmap, priv->offset, APPLE_PMGR_PS_TARGET,
+ FIELD_PREP(APPLE_PMGR_PS_TARGET, pstate));
+
+ return regmap_read_poll_timeout(
+ priv->regmap, priv->offset, reg,
+ (FIELD_GET(APPLE_PMGR_PS_ACTUAL, reg) == pstate), 1,
+ APPLE_PMGR_PS_SET_TIMEOUT_US);
+}
+
+static int apple_pmgr_on(struct power_domain *power_domain)
+{
+ return apple_pmgr_ps_set(power_domain, APPLE_PMGR_PS_ACTIVE);
+}
+
+static int apple_pmgr_off(struct power_domain *power_domain)
+{
+ return 0;
+}
+
+static int apple_pmgr_of_xlate(struct power_domain *power_domain,
+ struct ofnode_phandle_args *args)
+{
+ if (args->args_count != 0) {
+ debug("Invalid args_count: %d\n", args->args_count);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static const struct udevice_id apple_pmgr_ids[] = {
+ { .compatible = "apple,pmgr-pwrstate" },
+ { /* sentinel */ }
+};
+
+static int apple_pmgr_probe(struct udevice *dev)
+{
+ struct apple_pmgr_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ ret = dev_power_domain_on(dev);
+ if (ret)
+ return ret;
+
+ priv->regmap = syscon_get_regmap(dev->parent);
+ if (IS_ERR(priv->regmap))
+ return PTR_ERR(priv->regmap);
+
+ ret = dev_read_u32(dev, "reg", &priv->offset);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+struct power_domain_ops apple_pmgr_ops = {
+ .request = apple_pmgr_request,
+ .rfree = apple_pmgr_rfree,
+ .on = apple_pmgr_on,
+ .off = apple_pmgr_off,
+ .of_xlate = apple_pmgr_of_xlate,
+};
+
+U_BOOT_DRIVER(apple_pmgr) = {
+ .name = "apple_pmgr",
+ .id = UCLASS_POWER_DOMAIN,
+ .of_match = apple_pmgr_ids,
+ .ops = &apple_pmgr_ops,
+ .probe = apple_pmgr_probe,
+ .priv_auto = sizeof(struct apple_pmgr_priv),
+};