[PATCH v3 1/4] power-domain: Add QCOM RPMH Power Domain Driver Support

neil.armstrong at linaro.org neil.armstrong at linaro.org
Thu Jul 3 09:39:54 CEST 2025


Hi,

On 02/07/2025 20:01, Aswin Murugan wrote:
> 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; support for other power domains can be added
> in this driver.

Could you explain why you need 2 U_BOOT_DRIVER() ? since you simply
bind the node with the qcom_rpmhpd_drv from the qcom_rpmhpd probe
this could be a single driver, right ?

> 
> [1]:
> https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pmdomain/qcom/rpmhpd.c?id=3d25d46a255a83f94d7d4d4216f38aafc8e116b
> 
> Signed-off-by: Balaji Selvanathan <balaji.selvanathan at oss.qualcomm.com>
> Signed-off-by: Aswin Murugan <aswin.murugan at oss.qualcomm.com>
> ---
> v3:
> - No changes to this patch in v3
> 
> v2:
> - Added ARCH_SNAPDRAGON dependency to QCOM_POWER_DOMAIN Kconfig
> - In qcom-rpmhpd driver, the un-supported power domains are handled with warning
> ---
>   drivers/power/domain/Kconfig       |   8 +
>   drivers/power/domain/Makefile      |   1 +
>   drivers/power/domain/qcom-rpmhpd.c | 285 +++++++++++++++++++++++++++++
>   3 files changed, 294 insertions(+)
>   create mode 100644 drivers/power/domain/qcom-rpmhpd.c
> 
> diff --git a/drivers/power/domain/Kconfig b/drivers/power/domain/Kconfig
> index 5f5218bd8b5..1456df96cd1 100644
> --- a/drivers/power/domain/Kconfig
> +++ b/drivers/power/domain/Kconfig
> @@ -82,6 +82,14 @@ config MESON_SECURE_POWER_DOMAIN
>   	  Enable support for manipulating Amlogic Meson Secure power domains.
>   	  Support for Amlogic A1 series.
>   
> +config QCOM_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
> diff --git a/drivers/power/domain/Makefile b/drivers/power/domain/Makefile
> index 4d20c97d26c..950f83972dc 100644
> --- a/drivers/power/domain/Makefile
> +++ b/drivers/power/domain/Makefile
> @@ -21,3 +21,4 @@ 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
> +obj-$(CONFIG_QCOM_POWER_DOMAIN) += qcom-rpmhpd.o
> diff --git a/drivers/power/domain/qcom-rpmhpd.c b/drivers/power/domain/qcom-rpmhpd.c
> new file mode 100644
> index 00000000000..a8eab26bd23
> --- /dev/null
> +++ b/drivers/power/domain/qcom-rpmhpd.c
> @@ -0,0 +1,285 @@
> +// 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
> + * @peer:               A peer power domain in case Active only Voting is
> + *                      supported

Unused, drop

> + * @active_only:        True if it represents an Active only peer

Unused in code, only in structs, you can drop and add it later on.

> + * @corner:             current corner

Ditto

> + * @active_corner:      current active corner

Ditto

> + * @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
> + *                      cmd-db
> + * @state_synced:       Indicator that sync_state has been invoked for the rpmhpd resource

Ditto

> + * @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;
> +	struct rpmhpd	*peer;
> +	const bool	active_only;
> +	unsigned int	corner;
> +	unsigned int	active_corner;
> +	unsigned int	enable_corner;
> +	u32		level[RPMH_ARC_MAX_LEVELS];
> +	size_t		level_count;
> +	bool		enabled;
> +	const char	*res_name;
> +	u32		addr;
> +	bool		state_synced;
> +	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 = {
> +	.peer = &mmcx_ao,
> +	.res_name = "mmcx.lvl",
> +};
> +
> +static struct rpmhpd mmcx_ao = {
> +	.active_only = true,
> +	.peer = &mmcx,
> +	.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),
> +};
> +
> +static const struct udevice_id rpmhpd_match_table[] = {
> +	{ .compatible = "qcom,sa8775p-rpmhpd", .data = (ulong)&sa8775p_desc },
> +	{ }
> +};

Just add all SoC entries from the Linux driver, we can test and validate them.

Thanks,
Neil

> +
> +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->parent, 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 (%d) 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 (%d) not supported\n",
> +			    pd->id, 0);
> +		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;
> +	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,
> +	.probe = rpmhpd_probe,
> +	.ops = &qcom_rpmhpd_power_ops,
> +};
> +
> +int qcom_rpmhpd_bind(struct udevice *parent)
> +{
> +	struct rpmhpd_desc *data = (struct rpmhpd_desc *)dev_get_driver_data(parent);
> +	struct driver *drv;
> +	int ret;
> +
> +	/* Get a handle to the rpmhpd handler */
> +	drv = lists_driver_lookup_name("qcom_rpmhpd_drv");
> +	if (!drv)
> +		return -ENOENT;
> +
> +	/* Register the rpmhpd dev */
> +	ret = device_bind_with_driver_data(parent, drv, "qcom_rpmhpd_dev", (ulong)data,
> +					   dev_ofnode(parent), NULL);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +U_BOOT_DRIVER(qcom_rpmhpd) = {
> +	.name = "qcom_rpmhpd",
> +	.id = UCLASS_NOP,
> +	.of_match = rpmhpd_match_table,
> +	.bind = qcom_rpmhpd_bind,
> +};



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