[PATCH v5 4/6] soc: samsung: exynos-pmu: add Exynos850 CPU hotplug support
From: Alexey Klimov
Date: Tue Jun 09 2026 - 13:41:12 EST
Add cpuhotplug support for Exynos850 platforms. This SoC requires
its own specific set of writes/updates to PMU and PMU interrupts
generation block in order to put a CPU or a group of CPUs into
a different sleep states or prepare these entities for a CPU_OFF
or wake-up out of idle state or after CPU online.
Without these writes/updates the CPU(s) wake-up or online fails.
This also requires syscon regmap with raw spinlocks, so add
its initialisation to main exynos pmu probe() routine.
Signed-off-by: Alexey Klimov <alexey.klimov@xxxxxxxxxx>
---
drivers/soc/samsung/Makefile | 2 +-
drivers/soc/samsung/exynos-pmu.c | 24 ++++++++
drivers/soc/samsung/exynos-pmu.h | 1 +
drivers/soc/samsung/exynos850-pmu.c | 95 +++++++++++++++++++++++++++++
include/linux/soc/samsung/exynos-regs-pmu.h | 5 ++
5 files changed, 126 insertions(+), 1 deletion(-)
diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile
index 636a762608c9..7f544e3c1fcc 100644
--- a/drivers/soc/samsung/Makefile
+++ b/drivers/soc/samsung/Makefile
@@ -7,7 +7,7 @@ exynos_chipid-y += exynos-chipid.o exynos-asv.o
obj-$(CONFIG_EXYNOS_USI) += exynos-usi.o
obj-$(CONFIG_EXYNOS_PMU) += exynos_pmu.o
-exynos_pmu-y += exynos-pmu.o gs101-pmu.o
+exynos_pmu-y += exynos-pmu.o gs101-pmu.o exynos850-pmu.o
obj-$(CONFIG_EXYNOS_PMU_ARM_DRIVERS) += exynos3250-pmu.o exynos4-pmu.o \
exynos5250-pmu.o exynos5420-pmu.o
diff --git a/drivers/soc/samsung/exynos-pmu.c b/drivers/soc/samsung/exynos-pmu.c
index f170abe08ef1..cec0a7211c93 100644
--- a/drivers/soc/samsung/exynos-pmu.c
+++ b/drivers/soc/samsung/exynos-pmu.c
@@ -92,6 +92,14 @@ static const struct regmap_config regmap_smccfg = {
.use_raw_spinlock = true,
};
+static const struct regmap_config regmap_pmu = {
+ .name = "pmu_regs",
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+ .use_raw_spinlock = true,
+};
+
static const struct regmap_config regmap_pmu_intr = {
.name = "pmu_intr_gen",
.reg_bits = 32,
@@ -133,6 +141,7 @@ static const struct of_device_id exynos_pmu_of_device_ids[] = {
.compatible = "samsung,exynos7-pmu",
}, {
.compatible = "samsung,exynos850-pmu",
+ .data = &exynos850_pmu_data,
},
{ /*sentinel*/ },
};
@@ -488,6 +497,21 @@ static int exynos_pmu_probe(struct platform_device *pdev)
ret = of_syscon_register_regmap(dev->of_node, regmap);
if (ret)
return ret;
+ /*
+ * For SoCs that support cpuhotplug/cpuidle via PMU updates callbacks.
+ * Such callbacks are executed under raw_spinlock so we need a custom
+ * regmap too.
+ */
+ } else if (pmu_context->pmu_data && pmu_context->pmu_data->pmu_cpuhp) {
+ regmap = devm_regmap_init_mmio(dev, pmu_base_addr, ®map_pmu);
+ if (IS_ERR(regmap))
+ return dev_err_probe(dev, PTR_ERR(regmap),
+ "hotplug regmap init failed\n");
+
+ ret = of_syscon_register_regmap(dev->of_node, regmap);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "failed to register hotplug regmap with syscon\n");
} else {
/* let syscon create mmio regmap */
regmap = syscon_node_to_regmap(dev->of_node);
diff --git a/drivers/soc/samsung/exynos-pmu.h b/drivers/soc/samsung/exynos-pmu.h
index 733e188fa2b1..4ecbf53cd4f7 100644
--- a/drivers/soc/samsung/exynos-pmu.h
+++ b/drivers/soc/samsung/exynos-pmu.h
@@ -104,6 +104,7 @@ extern const struct exynos_pmu_data exynos5250_pmu_data;
extern const struct exynos_pmu_data exynos5420_pmu_data;
#endif
extern const struct exynos_pmu_data gs101_pmu_data;
+extern const struct exynos_pmu_data exynos850_pmu_data;
extern void pmu_raw_writel(u32 val, u32 offset);
extern u32 pmu_raw_readl(u32 offset);
diff --git a/drivers/soc/samsung/exynos850-pmu.c b/drivers/soc/samsung/exynos850-pmu.c
new file mode 100644
index 000000000000..0503c54d6363
--- /dev/null
+++ b/drivers/soc/samsung/exynos850-pmu.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2026 Linaro Ltd.
+ *
+ * Exynos850 PMU support
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/bits.h>
+#include <linux/printk.h>
+#include <linux/regmap.h>
+#include <linux/soc/samsung/exynos-pmu.h>
+#include <linux/soc/samsung/exynos-regs-pmu.h>
+#include <linux/topology.h>
+#include <asm/cputype.h>
+
+#include "exynos-pmu.h"
+
+static int exynos850_cpu_pmu_offline(struct exynos_pmu_context *pmu_context, unsigned int cpu)
+ __must_hold(&pmu_context->cpupm_lock)
+{
+ int cluster_id, core_id;
+ u32 reg, mask;
+
+ cluster_id = topology_cluster_id(cpu);
+ if (cluster_id < 0) {
+ pr_err_ratelimited("invalid cluster ID for cpu: %u\n", cpu);
+ return -EINVAL;
+ }
+
+ core_id = topology_core_id(cpu);
+ if (core_id < 0) {
+ pr_err_ratelimited("invalid core ID for cpu: %u\n", cpu);
+ return -EINVAL;
+ }
+
+ /* set cpu inform hint */
+ regmap_write(pmu_context->pmureg, EXYNOS850_CPU_INFORM(cpu), CPU_INFORM_C2);
+
+ mask = BIT(cpu);
+ regmap_update_bits(pmu_context->pmuintrgen, EXYNOS_GRP2_INTR_BID_ENABLE,
+ mask, BIT(cpu));
+
+ regmap_read(pmu_context->pmuintrgen, EXYNOS_GRP1_INTR_BID_UPEND, ®);
+ regmap_write(pmu_context->pmuintrgen, EXYNOS_GRP1_INTR_BID_CLEAR, reg & mask);
+
+ mask = (BIT(cpu + 8));
+ regmap_read(pmu_context->pmuintrgen, EXYNOS_GRP1_INTR_BID_UPEND, ®);
+ regmap_write(pmu_context->pmuintrgen, EXYNOS_GRP1_INTR_BID_CLEAR, reg & mask);
+
+ regmap_update_bits(pmu_context->pmureg,
+ EXYNOS850_CLUSTER_CPU_INT_EN(cluster_id, core_id), 1 << 3, 1 << 3);
+ return 0;
+}
+
+static int exynos850_cpu_pmu_online(struct exynos_pmu_context *pmu_context, unsigned int cpu)
+ __must_hold(&pmu_context->cpupm_lock)
+{
+ int cluster_id, core_id;
+ u32 reg, mask;
+
+ cluster_id = topology_cluster_id(cpu);
+ if (cluster_id < 0) {
+ pr_err_ratelimited("invalid cluster ID for cpu: %u\n", cpu);
+ return -EINVAL;
+ }
+
+ core_id = topology_core_id(cpu);
+ if (core_id < 0) {
+ pr_err_ratelimited("invalid core ID for cpu: %u\n", cpu);
+ return -EINVAL;
+ }
+
+ /* clear cpu inform hint */
+ regmap_write(pmu_context->pmureg, EXYNOS850_CPU_INFORM(cpu), CPU_INFORM_CLEAR);
+
+ mask = BIT(cpu);
+ regmap_update_bits(pmu_context->pmuintrgen, EXYNOS_GRP2_INTR_BID_ENABLE,
+ mask, (0 << cpu));
+
+ regmap_read(pmu_context->pmuintrgen, EXYNOS_GRP2_INTR_BID_UPEND, ®);
+
+ regmap_write(pmu_context->pmuintrgen, EXYNOS_GRP2_INTR_BID_CLEAR, reg & mask);
+
+ regmap_update_bits(pmu_context->pmureg,
+ EXYNOS850_CLUSTER_CPU_INT_EN(cluster_id, core_id), 1 << 3, 0 << 3);
+ return 0;
+}
+
+const struct exynos_pmu_data exynos850_pmu_data = {
+ .pmu_cpuhp = true,
+ .cpu_pmu_offline = exynos850_cpu_pmu_offline,
+ .cpu_pmu_online = exynos850_cpu_pmu_online,
+};
diff --git a/include/linux/soc/samsung/exynos-regs-pmu.h b/include/linux/soc/samsung/exynos-regs-pmu.h
index 9c4d3da41dbf..c7a82635fc36 100644
--- a/include/linux/soc/samsung/exynos-regs-pmu.h
+++ b/include/linux/soc/samsung/exynos-regs-pmu.h
@@ -1015,6 +1015,11 @@
#define EXYNOS_GRP2_INTR_BID_UPEND (0x0208)
#define EXYNOS_GRP2_INTR_BID_CLEAR (0x020c)
+/* Exynos850 PMU Alive */
+#define EXYNOS850_CPU_INFORM(cpu) (0x0860 + ((cpu) & 7) * 4)
+#define EXYNOS850_CLUSTER_CPU_OFFSET(cl, cpu) (0x1000 + (((cl) * 0x400) + ((cpu) * 0x80)))
+#define EXYNOS850_CLUSTER_CPU_INT_EN(cl, cpu) (EXYNOS850_CLUSTER_CPU_OFFSET(cl, cpu) + 0x44)
+
/* exynosautov920 */
#define EXYNOSAUTOV920_PHY_CTRL_USB20 (0x0710)
#define EXYNOSAUTOV920_PHY_CTRL_USB31 (0x0714)
--
2.51.0