power domain: add Tegra186 driver

In Tegra186, SoC power domains are manipulated using IPC requests to
the BPMP (Boot and Power Management Processor). This change implements a
driver that does that.

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

drivers/power/domain/Kconfig

@@ -17,4 +17,11 @@ config SANDBOX_POWER_DOMAIN
 	  simply accepts requests to power on/off various HW modules without
 	  actually doing anything beyond a little error checking.
 
+config TEGRA186_POWER_DOMAIN
+	bool "Enable Tegra186 BPMP-based power domain driver"
+	depends on TEGRA186_BPMP
+	help
+	  Enable support for manipulating Tegra's on-SoC power domains via IPC
+	  requests to the BPMP (Boot and Power Management Processor).
+
 endmenu

drivers/power/domain/Makefile

@@ -5,3 +5,4 @@
 obj-$(CONFIG_POWER_DOMAIN) += power-domain-uclass.o
 obj-$(CONFIG_SANDBOX_POWER_DOMAIN) += sandbox-power-domain.o
 obj-$(CONFIG_SANDBOX_POWER_DOMAIN) += sandbox-power-domain-test.o
+obj-$(CONFIG_TEGRA186_POWER_DOMAIN) += tegra186-power-domain.o

drivers/power/domain/tegra186-power-domain.c

@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <misc.h>
+#include <power-domain-uclass.h>
+#include <asm/arch-tegra/bpmp_abi.h>
+
+#define UPDATE	BIT(0)
+#define ON	BIT(1)
+
+static int tegra186_power_domain_request(struct power_domain *power_domain)
+{
+	debug("%s(power_domain=%p) (dev=%p, id=%lu)\n", __func__,
+	      power_domain, power_domain->dev, power_domain->id);
+
+	return 0;
+}
+
+static int tegra186_power_domain_free(struct power_domain *power_domain)
+{
+	debug("%s(power_domain=%p) (dev=%p, id=%lu)\n", __func__,
+	      power_domain, power_domain->dev, power_domain->id);
+
+	return 0;
+}
+
+static int tegra186_power_domain_common(struct power_domain *power_domain,
+					bool on)
+{
+	struct mrq_pg_update_state_request req;
+	int on_state = on ? ON : 0;
+	int ret;
+
+	req.partition_id = power_domain->id;
+	req.logic_state = UPDATE | on_state;
+	req.sram_state = UPDATE | on_state;
+	/*
+	 * Drivers manage their own clocks so they don't get out of sync, and
+	 * since some power domains have many clocks, only a subset of which
+	 * are actually needed depending on use-case.
+	 */
+	req.clock_state = UPDATE;
+
+	ret = misc_call(power_domain->dev->parent, MRQ_PG_UPDATE_STATE, &req,
+			sizeof(req), NULL, 0);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int tegra186_power_domain_on(struct power_domain *power_domain)
+{
+	debug("%s(power_domain=%p) (dev=%p, id=%lu)\n", __func__,
+	      power_domain, power_domain->dev, power_domain->id);
+
+	return tegra186_power_domain_common(power_domain, true);
+}
+
+static int tegra186_power_domain_off(struct power_domain *power_domain)
+{
+	debug("%s(power_domain=%p) (dev=%p, id=%lu)\n", __func__,
+	      power_domain, power_domain->dev, power_domain->id);
+
+	return tegra186_power_domain_common(power_domain, false);
+}
+
+struct power_domain_ops tegra186_power_domain_ops = {
+	.request = tegra186_power_domain_request,
+	.free = tegra186_power_domain_free,
+	.on = tegra186_power_domain_on,
+	.off = tegra186_power_domain_off,
+};
+
+static int tegra186_power_domain_probe(struct udevice *dev)
+{
+	debug("%s(dev=%p)\n", __func__, dev);
+
+	return 0;
+}
+
+U_BOOT_DRIVER(tegra186_power_domain) = {
+	.name = "tegra186_power_domain",
+	.id = UCLASS_POWER_DOMAIN,
+	.probe = tegra186_power_domain_probe,
+	.ops = &tegra186_power_domain_ops,
+};