pmdomain: marvell: Add PXA1908 power domains

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 <duje@dujemihanovic.xyz>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Author: LegoLivesMatter

MAINTAINERS

@@ -2871,6 +2871,7 @@ L:	linux-arm-kernel@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
 

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"

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/

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

drivers/pmdomain/marvell/Makefile

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_PXA1908_PM_DOMAINS) += pxa1908-power-controller.o

drivers/pmdomain/marvell/pxa1908-power-controller.c

@@ -0,0 +1,274 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2025 Duje Mihanović <duje@dujemihanovic.xyz>
+ */
+
+#include <linux/auxiliary_bus.h>
+#include <linux/container_of.h>
+#include <linux/dev_printk.h>
+#include <linux/device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/pm_domain.h>
+#include <linux/regmap.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 POWER_POLL_TIMEOUT_US	(25 * USEC_PER_MSEC)
+#define POWER_POLL_SLEEP_US	6
+
+#define NR_DOMAINS	5
+
+#define to_pxa1908_pd(_genpd) container_of(_genpd, struct pxa1908_pd, genpd)
+
+struct pxa1908_pd_ctrl {
+	struct generic_pm_domain *domains[NR_DOMAINS];
+	struct genpd_onecell_data onecell_data;
+	struct regmap *base;
+	struct device *dev;
+};
+
+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 pxa1908_pd_ctrl *ctrl;
+	struct generic_pm_domain genpd;
+	bool initialized;
+};
+
+static inline bool pxa1908_pd_is_on(struct pxa1908_pd *pd)
+{
+	struct pxa1908_pd_ctrl *ctrl = pd->ctrl;
+
+	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 = to_pxa1908_pd(genpd);
+	const struct pxa1908_pd_data *data = &pd->data;
+	struct pxa1908_pd_ctrl *ctrl = pd->ctrl;
+	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);
+
+	ret = regmap_read_poll_timeout(ctrl->base, APMU_PWR_STATUS_REG, status,
+				       status & data->pwr_state, POWER_POLL_SLEEP_US,
+				       POWER_ON_LATENCY_US + POWER_POLL_TIMEOUT_US);
+	if (ret == -ETIMEDOUT)
+		dev_err(ctrl->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 = to_pxa1908_pd(genpd);
+	const struct pxa1908_pd_data *data = &pd->data;
+	struct pxa1908_pd_ctrl *ctrl = pd->ctrl;
+	unsigned int status;
+	int ret;
+
+	regmap_clear_bits(ctrl->base, APMU_PWR_CTRL_REG, data->pwr_state);
+
+	ret = regmap_read_poll_timeout(ctrl->base, APMU_PWR_STATUS_REG, status,
+				       !(status & data->pwr_state), POWER_POLL_SLEEP_US,
+				       POWER_OFF_LATENCY_US + POWER_POLL_TIMEOUT_US);
+	if (ret == -ETIMEDOUT) {
+		dev_err(ctrl->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 = to_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 = to_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_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(&auxdev->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;
+
+	pd->ctrl = ctrl;
+
+	/* 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)
+			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);
+			if (ret)
+				return dev_err_probe(dev, ret,
+						     "failed to power off domain '%s'\n",
+						     pd->genpd.name);
+		}
+	}
+
+	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);
+
+	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->dev = dev;
+	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 <duje@dujemihanovic.xyz>");
+MODULE_DESCRIPTION("Marvell PXA1908 power domain driver");
+MODULE_LICENSE("GPL");