Add a power domain framework/uclass

Many SoCs allow power to be applied to or removed from portions of the SoC
(power domains). This may be used to save power. This API provides the
means to control such power management hardware.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>

1 files changed, 112 insertions, 0 deletions

diff --git a/drivers/power/domain/power-domain-uclass.c b/drivers/power/domain/power-domain-uclass.c
new file mode 100644
index 0000000000..1bb6262fa1
--- /dev/null
+++ b/drivers/power/domain/power-domain-uclass.c
@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <fdtdec.h>
+#include <power-domain.h>
+#include <power-domain-uclass.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static inline struct power_domain_ops *power_domain_dev_ops(struct udevice *dev)
+{
+	return (struct power_domain_ops *)dev->driver->ops;
+}
+
+static int power_domain_of_xlate_default(struct power_domain *power_domain,
+				       struct fdtdec_phandle_args *args)
+{
+	debug("%s(power_domain=%p)\n", __func__, power_domain);
+
+	if (args->args_count != 1) {
+		debug("Invalid args_count: %d\n", args->args_count);
+		return -EINVAL;
+	}
+
+	power_domain->id = args->args[0];
+
+	return 0;
+}
+
+int power_domain_get(struct udevice *dev, struct power_domain *power_domain)
+{
+	struct fdtdec_phandle_args args;
+	int ret;
+	struct udevice *dev_power_domain;
+	struct power_domain_ops *ops;
+
+	debug("%s(dev=%p, power_domain=%p)\n", __func__, dev, power_domain);
+
+	ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, dev->of_offset,
+					     "power-domains",
+					     "#power-domain-cells", 0, 0,
+					     &args);
+	if (ret) {
+		debug("%s: fdtdec_parse_phandle_with_args failed: %d\n",
+		      __func__, ret);
+		return ret;
+	}
+
+	ret = uclass_get_device_by_of_offset(UCLASS_POWER_DOMAIN, args.node,
+					     &dev_power_domain);
+	if (ret) {
+		debug("%s: uclass_get_device_by_of_offset failed: %d\n",
+		      __func__, ret);
+		return ret;
+	}
+	ops = power_domain_dev_ops(dev_power_domain);
+
+	power_domain->dev = dev_power_domain;
+	if (ops->of_xlate)
+		ret = ops->of_xlate(power_domain, &args);
+	else
+		ret = power_domain_of_xlate_default(power_domain, &args);
+	if (ret) {
+		debug("of_xlate() failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = ops->request(power_domain);
+	if (ret) {
+		debug("ops->request() failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+int power_domain_free(struct power_domain *power_domain)
+{
+	struct power_domain_ops *ops = power_domain_dev_ops(power_domain->dev);
+
+	debug("%s(power_domain=%p)\n", __func__, power_domain);
+
+	return ops->free(power_domain);
+}
+
+int power_domain_on(struct power_domain *power_domain)
+{
+	struct power_domain_ops *ops = power_domain_dev_ops(power_domain->dev);
+
+	debug("%s(power_domain=%p)\n", __func__, power_domain);
+
+	return ops->on(power_domain);
+}
+
+int power_domain_off(struct power_domain *power_domain)
+{
+	struct power_domain_ops *ops = power_domain_dev_ops(power_domain->dev);
+
+	debug("%s(power_domain=%p)\n", __func__, power_domain);
+
+	return ops->off(power_domain);
+}
+
+UCLASS_DRIVER(power_domain) = {
+	.id		= UCLASS_POWER_DOMAIN,
+	.name		= "power_domain",
+};