On Fri, 29 Aug 2025 at 18:22, Duje Mihanović <d...@dujemihanovic.xyz> wrote:
>
> Marvell's PXA1908 SoC has a few power domains for its VPU, GPU, image
> processor and DSI PHY. Add a driver to control these.
>
> Signed-off-by: Duje Mihanović <d...@dujemihanovic.xyz>
> ---
> v3:
> - Move driver back to pmdomain subsystem, use auxiliary bus to
> instantiate the driver
> - Drop redundant 'struct device' pointer in 'struct pxa1908_pd'
> - Fix pxa1908_pd_is_on() for DSI domain
> - Replace usleep_range() with fsleep()
> - Use dev_err_probe() where sensible
>
> v2:
> - Move to clk subsystem, instantiate the driver from the APMU clock
> driver
> - Drop clock handling
> - Squash MAINTAINERS patch
> ---
> MAINTAINERS | 1 +
> drivers/pmdomain/Kconfig | 1 +
> drivers/pmdomain/Makefile | 1 +
> drivers/pmdomain/marvell/Kconfig | 18 ++
> drivers/pmdomain/marvell/Makefile | 3 +
> .../pmdomain/marvell/pxa1908-power-controller.c | 268
> +++++++++++++++++++++
> 6 files changed, 292 insertions(+)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index
> 88f7bd50686eb1f6bcd4f34c6827f27ad44ea4e8..34e5e218e83e0ed9882b111f5251601dd6549d4e
> 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2871,6 +2871,7 @@ L: linux-arm-ker...@lists.infradead.org
> (moderated for non-subscribers)
> S: Maintained
> F: arch/arm64/boot/dts/marvell/mmp/
> F: drivers/clk/mmp/clk-pxa1908*.c
> +F: drivers/pmdomain/marvell/
> F: include/dt-bindings/clock/marvell,pxa1908.h
> F: include/dt-bindings/power/marvell,pxa1908-power.h
>
> diff --git a/drivers/pmdomain/Kconfig b/drivers/pmdomain/Kconfig
> index
> 91f04ace35d4b024fafdf6af4e26a179640eb82f..23076ae90e6641dea8e5dbc851d041cd7929cee6
> 100644
> --- a/drivers/pmdomain/Kconfig
> +++ b/drivers/pmdomain/Kconfig
> @@ -7,6 +7,7 @@ source "drivers/pmdomain/apple/Kconfig"
> source "drivers/pmdomain/arm/Kconfig"
> source "drivers/pmdomain/bcm/Kconfig"
> source "drivers/pmdomain/imx/Kconfig"
> +source "drivers/pmdomain/marvell/Kconfig"
> source "drivers/pmdomain/mediatek/Kconfig"
> source "drivers/pmdomain/qcom/Kconfig"
> source "drivers/pmdomain/renesas/Kconfig"
> diff --git a/drivers/pmdomain/Makefile b/drivers/pmdomain/Makefile
> index
> 7030f44a49df9e91b1c9d1b6d12690a6248671fb..ebc802f13eb953db750f5a9507caa64c637a957a
> 100644
> --- a/drivers/pmdomain/Makefile
> +++ b/drivers/pmdomain/Makefile
> @@ -5,6 +5,7 @@ obj-y += apple/
> obj-y += arm/
> obj-y += bcm/
> obj-y += imx/
> +obj-y += marvell/
> obj-y += mediatek/
> obj-y += qcom/
> obj-y += renesas/
> diff --git a/drivers/pmdomain/marvell/Kconfig
> b/drivers/pmdomain/marvell/Kconfig
> new file mode 100644
> index
> 0000000000000000000000000000000000000000..6c4084c826670266b7d948438f6e6d76acb416e2
> --- /dev/null
> +++ b/drivers/pmdomain/marvell/Kconfig
> @@ -0,0 +1,18 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +menu "Marvell PM Domains"
> + depends on ARCH_MMP || COMPILE_TEST
> +
> +config PXA1908_PM_DOMAINS
> + tristate "Marvell PXA1908 power domains"
> + depends on OF
> + depends on PM
> + default y if ARCH_MMP && ARM64
> + select AUXILIARY_BUS
> + select MFD_SYSCON
> + select PM_GENERIC_DOMAINS
> + select PM_GENERIC_DOMAINS_OF
> + help
> + Say Y here to enable support for Marvell PXA1908's power domanis.
> +
> +endmenu
> diff --git a/drivers/pmdomain/marvell/Makefile
> b/drivers/pmdomain/marvell/Makefile
> new file mode 100644
> index
> 0000000000000000000000000000000000000000..22c25013f6c856a2ca01a121e830279ee88eb0ed
> --- /dev/null
> +++ b/drivers/pmdomain/marvell/Makefile
> @@ -0,0 +1,3 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +obj-$(CONFIG_PXA1908_PM_DOMAINS) += pxa1908-power-controller.o
> diff --git a/drivers/pmdomain/marvell/pxa1908-power-controller.c
> b/drivers/pmdomain/marvell/pxa1908-power-controller.c
> new file mode 100644
> index
> 0000000000000000000000000000000000000000..29134629861abcf46959f9dcc98d3f05a4cc5b72
> --- /dev/null
> +++ b/drivers/pmdomain/marvell/pxa1908-power-controller.c
> @@ -0,0 +1,268 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright 2025 Duje Mihanović <d...@dujemihanovic.xyz>
> + */
> +
> +#include <linux/auxiliary_bus.h>
> +#include <linux/container_of.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_domain.h>
> +#include <linux/regmap.h>
> +#include <linux/units.h>
> +
> +#include <dt-bindings/power/marvell,pxa1908-power.h>
> +
> +/* VPU, GPU, ISP */
> +#define APMU_PWR_CTRL_REG 0xd8
> +#define APMU_PWR_BLK_TMR_REG 0xdc
> +#define APMU_PWR_STATUS_REG 0xf0
> +
> +/* DSI */
> +#define APMU_DEBUG 0x88
> +#define DSI_PHY_DVM_MASK BIT(31)
> +
> +#define POWER_ON_LATENCY_US 300
> +#define POWER_OFF_LATENCY_US 20
> +
> +#define NR_DOMAINS 5
> +
> +struct pxa1908_pd_ctrl {
> + struct generic_pm_domain *domains[NR_DOMAINS];
> + struct genpd_onecell_data onecell_data;
> + struct regmap *base;
> +};
> +
> +struct pxa1908_pd_data {
> + u32 reg_clk_res_ctrl;
> + u32 pwr_state;
> + u32 hw_mode;
> + bool keep_on;
> + int id;
> +};
> +
> +struct pxa1908_pd {
> + const struct pxa1908_pd_data data;
> + struct generic_pm_domain genpd;
> + bool initialized;
> +};
> +
> +static inline bool pxa1908_pd_is_on(struct pxa1908_pd *pd)
> +{
> + struct pxa1908_pd_ctrl *ctrl = dev_get_drvdata(&pd->genpd.dev);
The genpd.dev is owned by the genpd core and must not be used like this.
Please find another way to derive the needed data.
> +
> + return pd->data.id != PXA1908_POWER_DOMAIN_DSI
> + ? regmap_test_bits(ctrl->base, APMU_PWR_STATUS_REG,
> pd->data.pwr_state)
> + : regmap_test_bits(ctrl->base, APMU_DEBUG, DSI_PHY_DVM_MASK);
> +}
> +
> +static int pxa1908_pd_power_on(struct generic_pm_domain *genpd)
> +{
> + struct pxa1908_pd *pd = container_of(genpd, struct pxa1908_pd, genpd);
> + struct pxa1908_pd_ctrl *ctrl = dev_get_drvdata(&genpd->dev);
Ditto.
> + const struct pxa1908_pd_data *data = &pd->data;
> + unsigned int status;
> + int ret = 0;
> +
> + regmap_set_bits(ctrl->base, data->reg_clk_res_ctrl, data->hw_mode);
> + if (data->id != PXA1908_POWER_DOMAIN_ISP)
> + regmap_write(ctrl->base, APMU_PWR_BLK_TMR_REG, 0x20001fff);
> + regmap_set_bits(ctrl->base, APMU_PWR_CTRL_REG, data->pwr_state);
> +
> + fsleep(POWER_ON_LATENCY_US);
I assume the fsleep here is intentional and should be combined with
the poll-timeout below. Although I wonder why we can't just poll
immediately and by using some reasonable period+timeout instead?
> +
> + ret = regmap_read_poll_timeout(ctrl->base, APMU_PWR_STATUS_REG,
> status,
> + status & data->pwr_state, 6, 25 *
> USEC_PER_MSEC);
Please avoid hardcoding periods/timeouts here.
> + if (ret == -ETIMEDOUT)
> + dev_err(&genpd->dev, "timed out powering on domain '%s'\n",
> pd->genpd.name);
> +
> + return ret;
> +}
> +
> +static int pxa1908_pd_power_off(struct generic_pm_domain *genpd)
> +{
> + struct pxa1908_pd *pd = container_of(genpd, struct pxa1908_pd, genpd);
> + struct pxa1908_pd_ctrl *ctrl = dev_get_drvdata(&genpd->dev);
> + const struct pxa1908_pd_data *data = &pd->data;
> + unsigned int status;
> + int ret;
> +
> + regmap_clear_bits(ctrl->base, APMU_PWR_CTRL_REG, data->pwr_state);
> +
> + fsleep(POWER_OFF_LATENCY_US);
Ditto.
> +
> + ret = regmap_read_poll_timeout(ctrl->base, APMU_PWR_STATUS_REG,
> status,
> + !(status & data->pwr_state), 6, 25 *
> USEC_PER_MSEC);
Ditto.
> + if (ret == -ETIMEDOUT) {
> + dev_err(&genpd->dev, "timed out powering off domain '%s'\n",
> pd->genpd.name);
> + return ret;
> + }
> +
> + return regmap_clear_bits(ctrl->base, data->reg_clk_res_ctrl,
> data->hw_mode);
> +}
> +
> +static inline int pxa1908_dsi_power_on(struct generic_pm_domain *genpd)
> +{
> + struct pxa1908_pd_ctrl *ctrl = dev_get_drvdata(&genpd->dev);
> +
> + return regmap_set_bits(ctrl->base, APMU_DEBUG, DSI_PHY_DVM_MASK);
> +}
> +
> +static inline int pxa1908_dsi_power_off(struct generic_pm_domain *genpd)
> +{
> + struct pxa1908_pd_ctrl *ctrl = dev_get_drvdata(&genpd->dev);
> +
> + return regmap_clear_bits(ctrl->base, APMU_DEBUG, DSI_PHY_DVM_MASK);
> +}
> +
> +#define DOMAIN(_id, _name, ctrl, mode, state) \
> + [_id] = { \
> + .data = { \
> + .reg_clk_res_ctrl = ctrl, \
> + .hw_mode = BIT(mode), \
> + .pwr_state = BIT(state), \
> + .id = _id, \
> + }, \
> + .genpd = { \
> + .name = _name, \
> + .power_on = pxa1908_pd_power_on, \
> + .power_off = pxa1908_pd_power_off, \
> + }, \
> + }
> +
> +static struct pxa1908_pd domains[NR_DOMAINS] = {
> + DOMAIN(PXA1908_POWER_DOMAIN_VPU, "vpu", 0xa4, 19, 2),
> + DOMAIN(PXA1908_POWER_DOMAIN_GPU, "gpu", 0xcc, 11, 0),
> + DOMAIN(PXA1908_POWER_DOMAIN_GPU2D, "gpu2d", 0xf4, 11, 6),
> + DOMAIN(PXA1908_POWER_DOMAIN_ISP, "isp", 0x38, 15, 4),
> + [PXA1908_POWER_DOMAIN_DSI] = {
> + .genpd = {
> + .name = "dsi",
> + .power_on = pxa1908_dsi_power_on,
> + .power_off = pxa1908_dsi_power_off,
> + /*
> + * TODO: There is no DSI driver written yet and until
> then we probably
> + * don't want to power off the DSI PHY ever.
> + */
> + .flags = GENPD_FLAG_ALWAYS_ON,
> + },
> + .data = {
> + /* See above. */
> + .keep_on = true,
> + },
> + },
> +};
> +
> +static void pxa1908_pd_remove(struct auxiliary_device *auxdev)
> +{
> + struct pxa1908_pd *pd;
> + int ret;
> +
> + for (int i = NR_DOMAINS - 1; i >= 0; i--) {
> + pd = &domains[i];
> +
> + if (!pd->initialized)
> + continue;
> +
> + if (pxa1908_pd_is_on(pd) && !pd->data.keep_on)
> + pxa1908_pd_power_off(&pd->genpd);
> +
> + ret = pm_genpd_remove(&pd->genpd);
> + if (ret)
> + dev_err(&pd->genpd.dev, "failed to remove domain
> '%s': %d\n",
> + pd->genpd.name, ret);
> + }
> +}
> +
> +static int
> +pxa1908_pd_init(struct pxa1908_pd_ctrl *ctrl, int id, struct device *dev)
> +{
> + struct pxa1908_pd *pd = &domains[id];
> + int ret;
> +
> + ctrl->domains[id] = &pd->genpd;
> +
> + ret = pm_genpd_init(&pd->genpd, NULL, !pd->data.keep_on);
> + if (ret)
> + return dev_err_probe(dev, ret, "domain '%s' failed to
> initialize\n",
> + pd->genpd.name);
> +
> + dev_set_drvdata(&pd->genpd.dev, ctrl);
As stated above, please don't abuse the genpd.dev like this.
> +
> + /* Make sure the state of the hardware is synced with the domain
> table above. */
> + if (pd->data.keep_on) {
> + ret = pd->genpd.power_on(&pd->genpd);
This should be managed before pm_genpd_init() is called.
> + if (ret)
> + return dev_err_probe(dev, ret, "failed to power on
> domain '%s'\n",
> + pd->genpd.name);
> + } else {
> + if (pxa1908_pd_is_on(pd)) {
> + dev_warn(dev,
> + "domain '%s' is on despite being default
> off; powering off\n",
> + pd->genpd.name);
> +
> + ret = pd->genpd.power_off(&pd->genpd);
Ditto.
> + if (ret)
> + return dev_err_probe(dev, ret,
> + "failed to power off
> domain '%s'\n",
> + pd->genpd.name);
> + }
> + }
> +
> + pd->initialized = true;
> +
> + return 0;
> +}
> +
> +static int
> +pxa1908_pd_probe(struct auxiliary_device *auxdev, const struct
> auxiliary_device_id *aux_id)
> +{
> + struct pxa1908_pd_ctrl *ctrl;
> + struct device *dev = &auxdev->dev;
> + int ret;
> +
> + ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
> + if (!ctrl)
> + return -ENOMEM;
> +
> + auxiliary_set_drvdata(auxdev, ctrl);
> +
> + ctrl->base = syscon_node_to_regmap(dev->parent->of_node);
> + if (IS_ERR(ctrl->base))
> + return dev_err_probe(dev, PTR_ERR(ctrl->base), "no regmap
> available\n");
> +
> + ctrl->onecell_data.domains = ctrl->domains;
> + ctrl->onecell_data.num_domains = NR_DOMAINS;
> +
> + for (int i = 0; i < NR_DOMAINS; i++) {
> + ret = pxa1908_pd_init(ctrl, i, dev);
> + if (ret)
> + goto err;
> + }
> +
> + return of_genpd_add_provider_onecell(dev->parent->of_node,
> &ctrl->onecell_data);
> +
> +err:
> + pxa1908_pd_remove(auxdev);
> + return ret;
> +}
> +
> +static const struct auxiliary_device_id pxa1908_pd_id[] = {
> + { .name = "clk_pxa1908_apmu.power" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(auxiliary, pxa1908_pd_id);
> +
> +static struct auxiliary_driver pxa1908_pd_driver = {
> + .probe = pxa1908_pd_probe,
> + .remove = pxa1908_pd_remove,
> + .id_table = pxa1908_pd_id,
> +};
> +module_auxiliary_driver(pxa1908_pd_driver);
> +
> +MODULE_AUTHOR("Duje Mihanović <d...@dujemihanovic.xyz>");
> +MODULE_DESCRIPTION("Marvell PXA1908 power domain driver");
> +MODULE_LICENSE("GPL");
>
> --
> 2.51.0
>
Kind regards
Uffe
