power-domain: Add QCOM RPMH Power Domain Driver Support

Added support for Qualcomm RPMH power domain driver, responsible
for managing power domains on Qualcomm SoCs. This is a port of
the Linux RPMHPD driver [1] and sa8775p related changes. The
power domain driver currently has support to power on and off
MMCX power domain of sa8775p; support for other soc entries power
domains are stubbed, in future, the required soc support can be
added.

[1]:
https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pmdomain/qcom/rpmhpd.c?id=3d25d46a255a83f94d7d4d4216f38aafc8e116b

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Balaji Selvanathan <balaji.selvanathan@oss.qualcomm.com>
Signed-off-by: Aswin Murugan <aswin.murugan@oss.qualcomm.com>
Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Link: https://patch.msgid.link/20260213111009.1254360-2-aswin.murugan@oss.qualcomm.com
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>

drivers/power/domain/Kconfig

@@ -90,6 +90,14 @@ config MESON_SECURE_POWER_DOMAIN
 	  Enable support for manipulating Amlogic Meson Secure power domains.
 	  Support for Amlogic A1 series.
 
+config QCOM_RPMH_POWER_DOMAIN
+	bool "Enable the QCOM RPMH Power domain driver"
+	depends on POWER_DOMAIN && ARCH_SNAPDRAGON
+	help
+	  Generic RPMH power domain implementation for QCOM devices.
+	  The RPMH power domain driver is responsible for managing power
+	  domains on Qualcomm SoCs.
+
 config SANDBOX_POWER_DOMAIN
 	bool "Enable the sandbox power domain test driver"
 	depends on POWER_DOMAIN && SANDBOX

drivers/power/domain/Makefile

@@ -23,3 +23,4 @@ obj-$(CONFIG_TI_SCI_POWER_DOMAIN) += ti-sci-power-domain.o
 obj-$(CONFIG_TI_POWER_DOMAIN) += ti-power-domain.o
 obj-$(CONFIG_TI_OMAP_PRM_POWER_DOMAIN) += ti-omap-prm.o
 obj-$(CONFIG_ZYNQMP_POWER_DOMAIN) += zynqmp-power-domain.o
+obj-$(CONFIG_QCOM_RPMH_POWER_DOMAIN) += qcom-rpmhpd.o

drivers/power/domain/qcom-rpmhpd.c

@@ -0,0 +1,278 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018, The Linux Foundation. All rights reserved.
+// Copyright (c) 2025 Qualcomm Innovation Center, Inc. All rights reserved.
+
+#include <dm.h>
+#include <dm/lists.h>
+#include <power-domain.h>
+#include <asm/io.h>
+#include <linux/errno.h>
+
+#include <power-domain-uclass.h>
+#include <soc/qcom/cmd-db.h>
+#include <soc/qcom/rpmh.h>
+#include <dt-bindings/power/qcom-rpmpd.h>
+#include <dm/device_compat.h>
+
+#define RPMH_ARC_MAX_LEVELS	16
+
+/**
+ * struct rpmhpd - top level RPMh power domain resource data structure
+ * @dev:                rpmh power domain controller device
+ * @pd:                 generic_pm_domain corresponding to the power domain
+ * @parent:             generic_pm_domain corresponding to the parent's power domain
+ * @enable_corner:      lowest non-zero corner
+ * @level:              An array of level (vlvl) to corner (hlvl) mappings
+ *                      derived from cmd-db
+ * @level_count:        Number of levels supported by the power domain. max
+ *                      being 16 (0 - 15)
+ * @enabled:            true if the power domain is enabled
+ * @res_name:           Resource name used for cmd-db lookup
+ * @addr:               Resource address as looped up using resource name from
+ * @skip_retention_level: Indicate that retention level should not be used for the power domain
+ */
+struct rpmhpd {
+	struct udevice	*dev;
+	struct power_domain pd;
+	struct power_domain *parent;
+	unsigned int	enable_corner;
+	u32		level[RPMH_ARC_MAX_LEVELS];
+	size_t		level_count;
+	bool		enabled;
+	const char	*res_name;
+	u32		addr;
+	bool		skip_retention_level;
+};
+
+struct rpmhpd_desc {
+	struct rpmhpd **rpmhpds;
+	size_t num_pds;
+};
+
+/* RPMH powerdomains */
+static struct rpmhpd mmcx_ao;
+static struct rpmhpd mmcx = {
+	.res_name = "mmcx.lvl",
+};
+
+static struct rpmhpd mmcx_ao = {
+	.res_name = "mmcx.lvl",
+};
+
+/* SA8775P RPMH power domains */
+static struct rpmhpd *sa8775p_rpmhpds[] = {
+	[SA8775P_MMCX] = &mmcx,
+	[SA8775P_MMCX_AO] = &mmcx_ao,
+};
+
+static const struct rpmhpd_desc sa8775p_desc = {
+	.rpmhpds = sa8775p_rpmhpds,
+	.num_pds = ARRAY_SIZE(sa8775p_rpmhpds),
+};
+
+/* stub RPMH power domains mapped for unsupported platforms */
+static struct rpmhpd *stub_rpmhpds[] = {};
+
+static const struct rpmhpd_desc stub_desc = {
+	.rpmhpds = stub_rpmhpds,
+	.num_pds = ARRAY_SIZE(stub_rpmhpds),
+};
+
+static const struct udevice_id rpmhpd_match_table[] = {
+	{ .compatible = "qcom,sa8775p-rpmhpd", .data = (ulong)&sa8775p_desc },
+	{ .compatible = "qcom,qcs615-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,qcs8300-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,qdu1000-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sa8155p-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sa8540p-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sar2130p-rpmhpd", .data = (ulong)&stub_desc},
+	{ .compatible = "qcom,sc7180-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sc7280-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sc8180x-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sc8280xp-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sdm670-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sdm845-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sdx55-rpmhpd", .data = (ulong)&stub_desc},
+	{ .compatible = "qcom,sdx65-rpmhpd", .data = (ulong)&stub_desc},
+	{ .compatible = "qcom,sdx75-rpmhpd", .data = (ulong)&stub_desc},
+	{ .compatible = "qcom,sm4450-rpmhpd", .data = (ulong)&stub_desc},
+	{ .compatible = "qcom,sm6350-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sm7150-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sm8150-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sm8250-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sm8350-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sm8450-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sm8550-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sm8650-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,sm8750-rpmhpd", .data = (ulong)&stub_desc },
+	{ .compatible = "qcom,x1e80100-rpmhpd", .data = (ulong)&stub_desc },
+	{ }
+};
+
+static int rpmhpd_send_corner(struct rpmhpd *pd, int state,
+			      unsigned int corner, bool sync)
+{
+	struct tcs_cmd cmd = {
+		.addr = pd->addr,
+		.data = corner,
+	};
+
+	return rpmh_write(pd->dev, state, &cmd, 1);
+}
+
+static int rpmhpd_power_on(struct power_domain *pd)
+{
+	int ret;
+	unsigned int corner;
+	struct rpmhpd **rpmhpds;
+	const struct rpmhpd_desc *desc;
+	struct rpmhpd *curr_rpmhpd;
+
+	desc = (const struct rpmhpd_desc *)dev_get_driver_data(pd->dev);
+	if (!desc)
+		return -EINVAL;
+
+	rpmhpds = desc->rpmhpds;
+	curr_rpmhpd = rpmhpds[pd->id];
+
+	/* Do nothing for undefined power domains */
+	if (!curr_rpmhpd) {
+		log_warning("Power domain id (%ld) not supported\n",
+			    pd->id);
+		return 0;
+	}
+
+	corner = curr_rpmhpd->enable_corner;
+
+	ret = rpmhpd_send_corner(curr_rpmhpd, RPMH_ACTIVE_ONLY_STATE, corner,
+				 false);
+	if (!ret)
+		curr_rpmhpd->enabled = true;
+
+	return ret;
+}
+
+static int rpmhpd_power_off(struct power_domain *pd)
+{
+	int ret;
+	unsigned int corner;
+	struct rpmhpd **rpmhpds;
+	const struct rpmhpd_desc *desc;
+	struct rpmhpd *curr_rpmhpd;
+
+	desc = (const struct rpmhpd_desc *)dev_get_driver_data(pd->dev);
+	if (!desc)
+		return -EINVAL;
+
+	rpmhpds = desc->rpmhpds;
+	curr_rpmhpd = rpmhpds[pd->id];
+
+	/* Do nothing for undefined power domains */
+	if (!curr_rpmhpd) {
+		log_warning("Power domain id (%ld) not supported\n",
+			    pd->id);
+		return 0;
+	}
+
+	corner = 0;
+
+	ret = rpmhpd_send_corner(curr_rpmhpd, RPMH_ACTIVE_ONLY_STATE, corner,
+				 false);
+	if (!ret)
+		curr_rpmhpd->enabled = false;
+
+	return ret;
+}
+
+static int rpmhpd_update_level_mapping(struct rpmhpd *rpmhpd)
+{
+	int i;
+	const u16 *buf;
+
+	buf = cmd_db_read_aux_data(rpmhpd->res_name, &rpmhpd->level_count);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	/* 2 bytes used for each command DB aux data entry */
+	rpmhpd->level_count >>= 1;
+
+	if (rpmhpd->level_count > RPMH_ARC_MAX_LEVELS)
+		return -EINVAL;
+
+	for (i = 0; i < rpmhpd->level_count; i++) {
+		if (rpmhpd->skip_retention_level && buf[i] == RPMH_REGULATOR_LEVEL_RETENTION)
+			continue;
+
+		rpmhpd->level[i] = buf[i];
+
+		/* Remember the first corner with non-zero level */
+		if (!rpmhpd->level[rpmhpd->enable_corner] && rpmhpd->level[i])
+			rpmhpd->enable_corner = i;
+
+		/*
+		 * The AUX data may be zero padded. These 0 valued entries at
+		 * the end of the map must be ignored.
+		 */
+		if (i > 0 && rpmhpd->level[i] == 0) {
+			rpmhpd->level_count = i;
+			break;
+		}
+		debug("%s: ARC hlvl=%2d --> vlvl=%4u\n", rpmhpd->res_name, i,
+		      rpmhpd->level[i]);
+	}
+
+	return 0;
+}
+
+static int rpmhpd_probe(struct udevice *dev)
+{
+	int i, ret = 0;
+	struct rpmhpd **rpmhpds;
+	struct rpmhpd *priv;
+	const struct rpmhpd_desc *desc;
+
+	desc = (const struct rpmhpd_desc *)dev_get_driver_data(dev);
+	if (!desc)
+		return -EINVAL;
+
+	rpmhpds = desc->rpmhpds;
+
+	for (i = 0; i < desc->num_pds; i++) {
+		if (!rpmhpds[i])
+			continue;
+
+		priv = rpmhpds[i];
+		priv->dev = dev;
+		priv->addr = cmd_db_read_addr(priv->res_name);
+		if (!priv->addr) {
+			dev_err(dev, "Could not find RPMh address for resource %s\n",
+				priv->res_name);
+			return -ENODEV;
+		}
+
+		ret = cmd_db_read_slave_id(priv->res_name);
+		if (ret != CMD_DB_HW_ARC) {
+			dev_err(dev, "RPMh slave ID mismatch\n");
+			return -EINVAL;
+		}
+
+		ret = rpmhpd_update_level_mapping(priv);
+		if (ret)
+			return ret;
+	}
+
+	return ret;
+}
+
+static const struct power_domain_ops qcom_rpmhpd_power_ops = {
+	.on = rpmhpd_power_on,
+	.off = rpmhpd_power_off,
+};
+
+U_BOOT_DRIVER(qcom_rpmhpd_drv) = {
+	.name = "qcom_rpmhpd_drv",
+	.id = UCLASS_POWER_DOMAIN,
+	.of_match = rpmhpd_match_table,
+	.probe = rpmhpd_probe,
+	.ops = &qcom_rpmhpd_power_ops,
+};