power: zynqmp: Add power domain driver for ZynqMP

Driver should be enabled by CONFIG_POWER_DOMAIN=y and
CONFIG_ZYNQMP_POWER_DOMAIN=y. Power domain driver doesn't have own DT node
but it uses zynqmp firmware DT node that's why there is a need to bind
driver when firmware node is found.

Driver itself is simple. It is sending pmufw config object overlay for
enabling access to device which is done in ...domain_request().
In ...domain_on() capabilities are passed and node is requested.
This should be bare minimum of required to get power domain driver working.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Link: https://lore.kernel.org/r/f4b9433b91c0b18c375b061c7a4e29d428f70547.1644226055.git.michal.simek@xilinx.com

drivers/firmware/firmware-zynqmp.c

@@ -8,6 +8,7 @@
 #include <common.h>
 #include <cpu_func.h>
 #include <dm.h>
+#include <dm/lists.h>
 #include <log.h>
 #include <zynqmp_firmware.h>
 #include <asm/cache.h>
@@ -226,8 +227,27 @@ static const struct udevice_id zynqmp_firmware_ids[] = {
 	{ }
 };
 
+static int zynqmp_firmware_bind(struct udevice *dev)
+{
+	int ret;
+	struct udevice *child;
+
+	if (IS_ENABLED(CONFIG_ZYNQMP_POWER_DOMAIN)) {
+		ret = device_bind_driver_to_node(dev, "zynqmp_power_domain",
+						 "zynqmp_power_domain",
+						 dev_ofnode(dev), &child);
+		if (ret) {
+			printf("zynqmp power domain driver is not bound: %d\n", ret);
+			return ret;
+		}
+	}
+
+	return dm_scan_fdt_dev(dev);
+}
+
 U_BOOT_DRIVER(zynqmp_firmware) = {
 	.id = UCLASS_FIRMWARE,
 	.name = "zynqmp_firmware",
 	.of_match = zynqmp_firmware_ids,
+	.bind = zynqmp_firmware_bind,
 };

drivers/power/domain/Kconfig

@@ -88,4 +88,13 @@ config TI_POWER_DOMAIN
 	help
 	  Generic power domain implementation for TI K3 devices.
 
+config ZYNQMP_POWER_DOMAIN
+	bool "Enable the Xilinx ZynqMP Power domain driver"
+	depends on POWER_DOMAIN && ZYNQMP_FIRMWARE
+	help
+	  Generic power domain implementation for Xilinx ZynqMP devices.
+	  The driver should be enabled when system starts in very minimal
+	  configuration and it is extended at run time. Then enabling
+	  the driver will ensure that PMUFW enable access to requested IP.
+
 endmenu

drivers/power/domain/Makefile

@@ -16,3 +16,4 @@ obj-$(CONFIG_SANDBOX_POWER_DOMAIN) += sandbox-power-domain-test.o
 obj-$(CONFIG_TEGRA186_POWER_DOMAIN) += tegra186-power-domain.o
 obj-$(CONFIG_TI_SCI_POWER_DOMAIN) += ti-sci-power-domain.o
 obj-$(CONFIG_TI_POWER_DOMAIN) += ti-power-domain.o
+obj-$(CONFIG_ZYNQMP_POWER_DOMAIN) += zynqmp-power-domain.o

drivers/power/domain/zynqmp-power-domain.c

@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021, Xilinx. Inc.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <log.h>
+#include <malloc.h>
+#include <misc.h>
+#include <power-domain-uclass.h>
+#include <linux/bitops.h>
+
+#include <zynqmp_firmware.h>
+
+#define NODE_ID_LOCATION	5
+
+static unsigned int xpm_configobject[] = {
+	/* HEADER */
+	2,	/* Number of remaining words in the header */
+	1,	/* Number of sections included in config object */
+	PM_CONFIG_OBJECT_TYPE_OVERLAY,	/* Type of Config object as overlay */
+	/* SLAVE SECTION */
+
+	PM_CONFIG_SLAVE_SECTION_ID,	/* Section ID */
+	1,				/* Number of slaves */
+
+	0, /* Node ID which will be changed below */
+	PM_SLAVE_FLAG_IS_SHAREABLE,
+	PM_CONFIG_IPI_PSU_CORTEXA53_0_MASK |
+	PM_CONFIG_IPI_PSU_CORTEXR5_0_MASK |
+	PM_CONFIG_IPI_PSU_CORTEXR5_1_MASK, /* IPI Mask */
+};
+
+static int zynqmp_pm_request_node(const u32 node, const u32 capabilities,
+				  const u32 qos, const enum zynqmp_pm_request_ack ack)
+{
+	return xilinx_pm_request(PM_REQUEST_NODE, node, capabilities,
+				   qos, ack, NULL);
+}
+
+static int zynqmp_power_domain_request(struct power_domain *power_domain)
+{
+	/* Record power domain id */
+	xpm_configobject[NODE_ID_LOCATION] = power_domain->id;
+
+	zynqmp_pmufw_load_config_object(xpm_configobject, sizeof(xpm_configobject));
+
+	return 0;
+}
+
+static int zynqmp_power_domain_free(struct power_domain *power_domain)
+{
+	/* nop now */
+	return 0;
+}
+
+static int zynqmp_power_domain_on(struct power_domain *power_domain)
+{
+	return zynqmp_pm_request_node(power_domain->id,
+				      ZYNQMP_PM_CAPABILITY_ACCESS,
+				      ZYNQMP_PM_MAX_QOS,
+				      ZYNQMP_PM_REQUEST_ACK_BLOCKING);
+}
+
+static int zynqmp_power_domain_off(struct power_domain *power_domain)
+{
+	/* nop now */
+	return 0;
+}
+
+struct power_domain_ops zynqmp_power_domain_ops = {
+	.request = zynqmp_power_domain_request,
+	.rfree = zynqmp_power_domain_free,
+	.on = zynqmp_power_domain_on,
+	.off = zynqmp_power_domain_off,
+};
+
+static int zynqmp_power_domain_probe(struct udevice *dev)
+{
+	return 0;
+}
+
+U_BOOT_DRIVER(zynqmp_power_domain) = {
+	.name = "zynqmp_power_domain",
+	.id = UCLASS_POWER_DOMAIN,
+	.probe = zynqmp_power_domain_probe,
+	.ops = &zynqmp_power_domain_ops,
+};