[PATCH v7 1/4] power-domain: Add QCOM RPMH Power Domain Driver Support
Aswin Murugan
aswin.murugan at oss.qualcomm.com
Tue Jan 13 11:43:30 CET 2026
On 12/26/2025 3:16 PM, Sumit Garg wrote:
> Hi Aswin,
>
> Thanks for the driver port.
>
> On Mon, Dec 22, 2025 at 05:18:20PM +0530, 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 of sa8775p;
> IIUC, the MMCX power domain relates to multimedia use-cases. Do you have
> any such use-case for that in U-Boot? IOW, I don't see a user of the
> RPMh functionality you are trying to add in this patch-set.
>
> Yes, MMCX is tied to multimedia, and in our case, it is required for
> display initialization in U-Boot.
>
>
> If it's just meant for now to not have live DT fixups then having just
> the stubbed power domains will be sufficient.
>
> -Sumit
>
> Yes, the purpose of introducing stubbed power domains is to eliminate the need for live Device Tree fixups related to power domains
>
> -Aswin
>
>
>> 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 at linaro.org>
>> Signed-off-by: Balaji Selvanathan <balaji.selvanathan at oss.qualcomm.com>
>> Signed-off-by: Aswin Murugan <aswin.murugan at oss.qualcomm.com>
>> ---
>> v7:
>> - No changes to this patch in v7
>>
>> v6:
>> - Initialized ret with 0 in rpmhpd_probe()
>>
>> v5:
>> - Changed the first argument passed to rpmh_write as pd->dev
>> - Added (ulong) casting in rpmhpd_match_table to address the warning.
>>
>> v4:
>> - Added all SoC entries from the Linux driver and stubbed it
>> - Removed "qcom_rpmhpd" driver
>> - Removed unused members in struct rpmhpd
>>
>> 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
>> in rpmhpd_power_on() & rpmhpd_power_off()
>> ---
>> drivers/power/domain/Kconfig | 8 +
>> drivers/power/domain/Makefile | 1 +
>> drivers/power/domain/qcom-rpmhpd.c | 278 +++++++++++++++++++++++++++++
>> 3 files changed, 287 insertions(+)
>> create mode 100644 drivers/power/domain/qcom-rpmhpd.c
>>
>> diff --git a/drivers/power/domain/Kconfig b/drivers/power/domain/Kconfig
>> index 0ad885c9e8b..48e841c638e 100644
>> --- a/drivers/power/domain/Kconfig
>> +++ b/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_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 8e03f620437..1c2c64b0964 100644
>> --- a/drivers/power/domain/Makefile
>> +++ b/drivers/power/domain/Makefile
>> @@ -22,3 +22,4 @@ 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..f51bc9a4bbb
>> --- /dev/null
>> +++ b/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,
>> +};
>> --
>> 2.34.1
>>
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