On Thu, 21 Aug 2025 at 13:19, 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.
>
> Also create a separate Kconfig entry for the PXA1908 clock drivers to
> allow satisfying the driver's dependencies.
>
> Signed-off-by: Duje Mihanović <d...@dujemihanovic.xyz>
> ---
> v2:
> - Move to clk subsystem, instantiate the driver from the APMU clock
> driver
> - Drop clock handling
> - Squash MAINTAINERS patch
> ---
> MAINTAINERS | 5 +
> drivers/clk/Kconfig | 1 +
> drivers/clk/mmp/Kconfig | 14 ++
> drivers/clk/mmp/Makefile | 5 +-
> drivers/clk/mmp/clk-pxa1908-apmu.c | 2 +-
> drivers/clk/mmp/clk.h | 2 +
> drivers/clk/mmp/pxa1908-power-domains.c | 253
> ++++++++++++++++++++++++++++++++
> 7 files changed, 280 insertions(+), 2 deletions(-)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index
> daf520a13bdf6a991c0160a96620f40308c29ee0..309090a5ba6c03a2c00d3e39a896748958ffa593
> 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2869,9 +2869,14 @@ ARM/Marvell PXA1908 SOC support
> M: Duje Mihanović <d...@dujemihanovic.xyz>
> L: linux-arm-ker...@lists.infradead.org (moderated for non-subscribers)
> S: Maintained
> +C: ircs://irc.oftc.net/pxa1908-mainline
> +F: Documentation/devicetree/bindings/clock/marvell,pxa1908.yaml
> F: arch/arm64/boot/dts/marvell/mmp/
> +F: drivers/clk/mmp/Kconfig
> F: drivers/clk/mmp/clk-pxa1908*.c
> +F: drivers/clk/mmp/pxa1908-power-domains.c
> F: include/dt-bindings/clock/marvell,pxa1908.h
> +F: include/dt-bindings/power/marvell,pxa1908-power.h
>
> ARM/Mediatek RTC DRIVER
> M: Eddie Huang <eddie.hu...@mediatek.com>
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index
> 4d56475f94fc1e28823fe6aee626a96847d4e6d5..68a9641fc649a23013b2d8a9e9f5ecb31d623abb
> 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -511,6 +511,7 @@ source "drivers/clk/imx/Kconfig"
> source "drivers/clk/ingenic/Kconfig"
> source "drivers/clk/keystone/Kconfig"
> source "drivers/clk/mediatek/Kconfig"
> +source "drivers/clk/mmp/Kconfig"
> source "drivers/clk/meson/Kconfig"
> source "drivers/clk/mstar/Kconfig"
> source "drivers/clk/microchip/Kconfig"
> diff --git a/drivers/clk/mmp/Kconfig b/drivers/clk/mmp/Kconfig
> new file mode 100644
> index
> 0000000000000000000000000000000000000000..9dca5b50fd15a1d2ca71163c649a51592da15021
> --- /dev/null
> +++ b/drivers/clk/mmp/Kconfig
> @@ -0,0 +1,14 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +config COMMON_CLK_PXA1908
> + bool "Clock driver for Marvell PXA1908"
> + depends on ARCH_MMP || COMPILE_TEST
> + depends on OF
> + default y if ARCH_MMP && ARM64
> + select PM
> + select PM_GENERIC_DOMAINS
> + select PM_GENERIC_DOMAINS_OF
> + select REGMAP_MMIO
> + help
> + This driver supports the Marvell PXA1908 SoC clocks. The SoC's power
> + domains are also supported by the driver.
> diff --git a/drivers/clk/mmp/Makefile b/drivers/clk/mmp/Makefile
> index
> 062cd87fa8ddcc6808b6236f8c4dd524aaf02030..0b9ad29087ff23b8dc247bfd38f0e55382e16759
> 100644
> --- a/drivers/clk/mmp/Makefile
> +++ b/drivers/clk/mmp/Makefile
> @@ -11,4 +11,7 @@ obj-$(CONFIG_MACH_MMP_DT) += clk-of-pxa168.o clk-of-pxa910.o
> obj-$(CONFIG_COMMON_CLK_MMP2) += clk-of-mmp2.o clk-pll.o pwr-island.o
> obj-$(CONFIG_COMMON_CLK_MMP2_AUDIO) += clk-audio.o
>
> -obj-$(CONFIG_ARCH_MMP) += clk-of-pxa1928.o clk-pxa1908-apbc.o
> clk-pxa1908-apbcp.o clk-pxa1908-apmu.o clk-pxa1908-mpmu.o
> +obj-$(CONFIG_COMMON_CLK_PXA1908) += clk-pxa1908-apbc.o clk-pxa1908-apbcp.o \
> + clk-pxa1908-mpmu.o clk-pxa1908-apmu.o pxa1908-power-domains.o
> +
> +obj-$(CONFIG_ARCH_MMP) += clk-of-pxa1928.o
> diff --git a/drivers/clk/mmp/clk-pxa1908-apmu.c
> b/drivers/clk/mmp/clk-pxa1908-apmu.c
> index
> d3a070687fc5b9fb5338f377f82e7664ca0aac29..3d4494cfc9bc28e1e614a11f56aa3d211fb6ec26
> 100644
> --- a/drivers/clk/mmp/clk-pxa1908-apmu.c
> +++ b/drivers/clk/mmp/clk-pxa1908-apmu.c
> @@ -98,7 +98,7 @@ static int pxa1908_apmu_probe(struct platform_device *pdev)
>
> pxa1908_axi_periph_clk_init(pxa_unit);
>
> - return 0;
> + return pxa1908_pd_register(&pdev->dev);
> }
>
> static const struct of_device_id pxa1908_apmu_match_table[] = {
> diff --git a/drivers/clk/mmp/clk.h b/drivers/clk/mmp/clk.h
> index
> c83cec169ddc5e3fcd0561cf857f248178c25b68..6d3d089a0372fa48c8f61aceacdd1b2059f2c8dd
> 100644
> --- a/drivers/clk/mmp/clk.h
> +++ b/drivers/clk/mmp/clk.h
> @@ -258,4 +258,6 @@ struct generic_pm_domain *mmp_pm_domain_register(const
> char *name,
> u32 power_on, u32 reset, u32 clock_enable,
> unsigned int flags, spinlock_t *lock);
>
> +int pxa1908_pd_register(struct device *dev);
> +
> #endif
> diff --git a/drivers/clk/mmp/pxa1908-power-domains.c
> b/drivers/clk/mmp/pxa1908-power-domains.c
By looking at the implementation of the power-domain code below, it
seems to me that this code is better maintained within the pmdomain
subsystem (drivers/pmdomain/pxa perhaps). May I suggest that you move
it there.
I guess the easiest way to do this is to export the
pxa1908_pd_register() function - but you could explore using the
auxiliary bus too, to instantiate a power-domain driver as an
auxiliary driver.
Other than that, the code looks good to me!
Kind regards
Uffe
> new file mode 100644
> index
> 0000000000000000000000000000000000000000..9f698a17e5a920d0472b74fce137b42cae0569d2
> --- /dev/null
> +++ b/drivers/clk/mmp/pxa1908-power-domains.c
> @@ -0,0 +1,253 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright 2025 Duje Mihanović <d...@dujemihanovic.xyz>
> + */
> +
> +#include <linux/container_of.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>
> +
> +#include "clk.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 genpd_onecell_data onecell_data;
> + struct generic_pm_domain *domains[NR_DOMAINS];
> + struct regmap *base;
> +};
> +
> +struct pxa1908_pd_data {
> + u32 reg_clk_res_ctrl;
> + u32 hw_mode;
> + u32 pwr_state;
> + bool keep_on;
> + int id;
> +};
> +
> +struct pxa1908_pd {
> + const struct pxa1908_pd_data data;
> + struct pxa1908_pd_ctrl *ctrl;
> + struct generic_pm_domain genpd;
> + struct device *dev;
> + bool initialized;
> + int num_clks;
> +};
> +
> +static bool pxa1908_pd_is_on(struct pxa1908_pd *pd)
> +{
> + struct pxa1908_pd_ctrl *ctrl = pd->ctrl;
> +
> + return regmap_test_bits(ctrl->base, APMU_PWR_STATUS_REG,
> pd->data.pwr_state);
> +}
> +
> +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 = pd->ctrl;
> + 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);
> +
> + usleep_range(POWER_ON_LATENCY_US, POWER_ON_LATENCY_US * 2);
> +
> + ret = regmap_read_poll_timeout(ctrl->base, APMU_PWR_STATUS_REG,
> status,
> + status & data->pwr_state, 6, 25 *
> USEC_PER_MSEC);
> + if (ret == -ETIMEDOUT)
> + dev_err(pd->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 = pd->ctrl;
> + 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);
> +
> + usleep_range(POWER_OFF_LATENCY_US, POWER_OFF_LATENCY_US * 2);
> +
> + ret = regmap_read_poll_timeout(ctrl->base, APMU_PWR_STATUS_REG,
> status,
> + !(status & data->pwr_state), 6, 25 *
> USEC_PER_MSEC);
> + if (ret == -ETIMEDOUT) {
> + dev_err(pd->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 *pd = container_of(genpd, struct pxa1908_pd, genpd);
> + struct pxa1908_pd_ctrl *ctrl = pd->ctrl;
> +
> + 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 *pd = container_of(genpd, struct pxa1908_pd, genpd);
> + struct pxa1908_pd_ctrl *ctrl = pd->ctrl;
> +
> + 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_cleanup(struct pxa1908_pd_ctrl *ctrl)
> +{
> + struct pxa1908_pd *pd;
> + int ret;
> +
> + for (int i = NR_DOMAINS - 1; i >= 0; i--) {
> + pd = &domains[i];
> +
> + if (!pd->initialized)
> + continue;
> +
> + ret = pm_genpd_remove(&pd->genpd);
> + if (ret)
> + dev_err(pd->dev, "failed to remove domain '%s': %d\n",
> + pd->genpd.name, ret);
> + if (pxa1908_pd_is_on(pd) && !pd->data.keep_on)
> + pxa1908_pd_power_off(&pd->genpd);
> + }
> +}
> +
> +static int
> +pxa1908_pd_init(struct pxa1908_pd_ctrl *ctrl, int id, struct device *dev)
> +{
> + struct pxa1908_pd *pd = &domains[id];
> + int ret;
> +
> + pd->dev = dev;
> + pd->ctrl = ctrl;
> + ctrl->domains[id] = &pd->genpd;
> +
> + /* 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);
> + if (ret) {
> + dev_err(dev, "failed to power on domain '%s': %d\n",
> pd->genpd.name, ret);
> + return ret;
> + }
> + } 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 = pxa1908_pd_power_off(&pd->genpd);
> + if (ret) {
> + dev_err(dev, "failed to power off domain
> '%s': %d\n",
> + pd->genpd.name, ret);
> + return ret;
> + }
> + }
> + }
> +
> + ret = pm_genpd_init(&pd->genpd, NULL, !pd->data.keep_on);
> + if (ret) {
> + dev_err(dev, "domain '%s' failed to initialize: %d\n",
> pd->genpd.name, ret);
> + return ret;
> + }
> +
> + pd->initialized = true;
> +
> + return 0;
> +}
> +
> +int pxa1908_pd_register(struct device *dev)
> +{
> + struct pxa1908_pd_ctrl *ctrl;
> + int ret;
> +
> + ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
> + if (!ctrl)
> + return -ENOMEM;
> +
> + ctrl->base = syscon_node_to_regmap(dev->of_node);
> + if (IS_ERR(ctrl->base)) {
> + dev_err(dev, "no regmap available\n");
> + return PTR_ERR(ctrl->base);
> + }
> +
> + 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->of_node,
> &ctrl->onecell_data);
> +
> +err:
> + pxa1908_pd_cleanup(ctrl);
> + return ret;
> +}
>
> --
> 2.50.1
>
