* [PATCH v7 1/6] dt-bindings: soc: move,rename google,gs101-pmu-intr-gen and add exynos850
2026-09-30 0:12 [PATCH v7 0/6] Exynos-pmu: Generalise cpu{hotplug,idle},PMU intr gen and add Exynos850 CPU hotplug Alexey Klimov
@ 2026-09-30 0:12 ` Alexey Klimov
2026-09-30 0:12 ` [PATCH v7 2/6] dt-bindings: soc: samsung: exynos-pmu: Require pmu-intr-gen-syscon for Exynos850 Alexey Klimov
` (4 subsequent siblings)
5 siblings, 0 replies; 11+ messages in thread
From: Alexey Klimov @ 2026-09-30 0:12 UTC (permalink / raw)
To: Sam Protsenko, linux-samsung-soc, Krzysztof Kozlowski, Peter Griffin
Cc: André Draszik, Tudor Ambarus, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Alim Akhtar, Henrik Grimler,
linux-arm-kernel, devicetree, linux-kernel
The PMU interrupt generation block introduced for the Google GS101 is
actually a standard Samsung Exynos IP block found in older SoCs, such
as the Exynos850, and is not exclusive to Google SoCs. To accurately
reflect its origin, move the schema file to under soc/samsung/
directory and rename it.
Concurrently, add the new "samsung,exynos850-pmu-intr-gen" compatible
string to the bindings. Support for this block is required to enable
power management features like CPU hotplug and idle states on Exynos850
platforms.
Also, move this file under Exynos850 SoC in MAINTAINERS entry.
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
---
.../samsung,exynos850-pmu-intr-gen.yaml} | 8 +++++---
MAINTAINERS | 2 +-
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/soc/google/google,gs101-pmu-intr-gen.yaml b/Documentation/devicetree/bindings/soc/samsung/samsung,exynos850-pmu-intr-gen.yaml
similarity index 70%
rename from Documentation/devicetree/bindings/soc/google/google,gs101-pmu-intr-gen.yaml
rename to Documentation/devicetree/bindings/soc/samsung/samsung,exynos850-pmu-intr-gen.yaml
index 2be022ca6a7d..df23467d0e0e 100644
--- a/Documentation/devicetree/bindings/soc/google/google,gs101-pmu-intr-gen.yaml
+++ b/Documentation/devicetree/bindings/soc/samsung/samsung,exynos850-pmu-intr-gen.yaml
@@ -1,10 +1,10 @@
# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
%YAML 1.2
---
-$id: http://devicetree.org/schemas/soc/google/google,gs101-pmu-intr-gen.yaml#
+$id: http://devicetree.org/schemas/soc/samsung/samsung,exynos850-pmu-intr-gen.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
-title: Google Power Management Unit (PMU) Interrupt Generation
+title: Samsung Power Management Unit (PMU) Interrupt Generation
description: |
PMU interrupt generator for handshaking between PMU through interrupts.
@@ -15,7 +15,9 @@ maintainers:
properties:
compatible:
items:
- - const: google,gs101-pmu-intr-gen
+ - enum:
+ - google,gs101-pmu-intr-gen
+ - samsung,exynos850-pmu-intr-gen
- const: syscon
reg:
diff --git a/MAINTAINERS b/MAINTAINERS
index 1c02b919d6ae..137297bf508b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11298,7 +11298,6 @@ P: Documentation/process/maintainer-soc-clean-dts.rst
C: irc://irc.oftc.net/pixel6-kernel-dev
F: Documentation/devicetree/bindings/clock/google,gs101-clock.yaml
F: Documentation/devicetree/bindings/phy/google,lga-usb-phy.yaml
-F: Documentation/devicetree/bindings/soc/google/google,gs101-pmu-intr-gen.yaml
F: Documentation/devicetree/bindings/usb/google,lga-dwc3.yaml
F: arch/arm64/boot/dts/exynos/google/
F: drivers/clk/samsung/clk-gs101.c
@@ -24629,6 +24628,7 @@ L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
L: linux-samsung-soc@vger.kernel.org
S: Maintained
F: Documentation/devicetree/bindings/clock/samsung,exynos850-clock.yaml
+F: Documentation/devicetree/bindings/soc/samsung/samsung,exynos850-pmu-intr-gen.yaml
F: arch/arm64/boot/dts/exynos/exynos850*
F: drivers/clk/samsung/clk-exynos850.c
F: include/dt-bindings/clock/exynos850.h
--
2.51.0
^ permalink raw reply [flat|nested] 11+ messages in thread* [PATCH v7 2/6] dt-bindings: soc: samsung: exynos-pmu: Require pmu-intr-gen-syscon for Exynos850
2026-09-30 0:12 [PATCH v7 0/6] Exynos-pmu: Generalise cpu{hotplug,idle},PMU intr gen and add Exynos850 CPU hotplug Alexey Klimov
2026-09-30 0:12 ` [PATCH v7 1/6] dt-bindings: soc: move,rename google,gs101-pmu-intr-gen and add exynos850 Alexey Klimov
@ 2026-09-30 0:12 ` Alexey Klimov
2026-09-30 0:12 ` [PATCH v7 3/6] soc: samsung: exynos-pmu: generalise gs101-specific cpu{idle,hotplug} for Exynos SoCs Alexey Klimov
` (3 subsequent siblings)
5 siblings, 0 replies; 11+ messages in thread
From: Alexey Klimov @ 2026-09-30 0:12 UTC (permalink / raw)
To: Sam Protsenko, linux-samsung-soc, Krzysztof Kozlowski, Peter Griffin
Cc: André Draszik, Tudor Ambarus, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Alim Akhtar, Henrik Grimler,
linux-arm-kernel, devicetree, linux-kernel
Update the Exynos PMU schema to mandate the 'google,pmu-intr-gen-syscon'
property for the 'samsung,exynos850-pmu' compatible so the driver can
obtain the necessary syscon regmap.
The Exynos850 PMU relies on a separate system controller block to handle
interrupts generation, similar to the hardware design of the GS101
SoC. To ensure the hardware is correctly described, this syscon phandle
must be explicitly provided.
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
---
Documentation/devicetree/bindings/soc/samsung/exynos-pmu.yaml | 1 +
1 file changed, 1 insertion(+)
diff --git a/Documentation/devicetree/bindings/soc/samsung/exynos-pmu.yaml b/Documentation/devicetree/bindings/soc/samsung/exynos-pmu.yaml
index 5bd39876e3b3..7d58976dccc4 100644
--- a/Documentation/devicetree/bindings/soc/samsung/exynos-pmu.yaml
+++ b/Documentation/devicetree/bindings/soc/samsung/exynos-pmu.yaml
@@ -196,6 +196,7 @@ allOf:
contains:
enum:
- google,gs101-pmu
+ - samsung,exynos850-pmu
then:
properties:
reboot-mode:
--
2.51.0
^ permalink raw reply [flat|nested] 11+ messages in thread* [PATCH v7 3/6] soc: samsung: exynos-pmu: generalise gs101-specific cpu{idle,hotplug} for Exynos SoCs
2026-09-30 0:12 [PATCH v7 0/6] Exynos-pmu: Generalise cpu{hotplug,idle},PMU intr gen and add Exynos850 CPU hotplug Alexey Klimov
2026-09-30 0:12 ` [PATCH v7 1/6] dt-bindings: soc: move,rename google,gs101-pmu-intr-gen and add exynos850 Alexey Klimov
2026-09-30 0:12 ` [PATCH v7 2/6] dt-bindings: soc: samsung: exynos-pmu: Require pmu-intr-gen-syscon for Exynos850 Alexey Klimov
@ 2026-09-30 0:12 ` Alexey Klimov
2026-09-30 0:12 ` [PATCH v7 4/6] soc: samsung: exynos-pmu: add Exynos850 CPU hotplug support Alexey Klimov
` (2 subsequent siblings)
5 siblings, 0 replies; 11+ messages in thread
From: Alexey Klimov @ 2026-09-30 0:12 UTC (permalink / raw)
To: Sam Protsenko, linux-samsung-soc, Krzysztof Kozlowski, Peter Griffin
Cc: André Draszik, Tudor Ambarus, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Alim Akhtar, Henrik Grimler,
linux-arm-kernel, devicetree, linux-kernel
The cpuhotplug and cpuidle support for GS101-based SoCs which
utilizes GS101 PMU interrupts generation block can be generalised
to be (re)used for other Exynos-based SoCs. Also, the GS101 PMU
interrupts generation block is not exclusive to Google GS101 SoCs
and should be made more Exynos-generic.
Specifically, apply the following changes:
- rename gs101-specific calls, structs, names to be exynos-prefixed;
- move exynos_pmu_context and CPU_INFORM_* defines into exynos-pmu.h;
- introduce cpu_pmu_{offline,online} callbacks in driver-specific
exynos_pmu_data which can be used to hold PMU and PMU intr gen
update routines for different platforms and update cpuidle and cpuhotplug
support to use them;
- add checks for the presense of cpu_pmu_{offline,online} callbacks;
- move and rename gs101-specific cpu{offline,online} PMU updates
routines into gs101-pmu.c file, also removing underscore prefix;
- update gs101_pmu_data to use newly introduced callbacks;
- rename PMU interrupts generation GS101_INTR_* regs to EXYNOS_INTR_*.
This allows other platforms to add cpuhotplug and cpuidle support in
a similar manner, using their own platform-specific PMU and
PMU intr gen update routines.
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Tested-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
---
drivers/soc/samsung/exynos-pmu.c | 125 ++++++----------------------
drivers/soc/samsung/exynos-pmu.h | 33 ++++++++
drivers/soc/samsung/gs101-pmu.c | 51 ++++++++++++
include/linux/soc/samsung/exynos-regs-pmu.h | 10 +--
4 files changed, 114 insertions(+), 105 deletions(-)
diff --git a/drivers/soc/samsung/exynos-pmu.c b/drivers/soc/samsung/exynos-pmu.c
index c764f35fbfc2..9efaaf4696cf 100644
--- a/drivers/soc/samsung/exynos-pmu.c
+++ b/drivers/soc/samsung/exynos-pmu.c
@@ -24,24 +24,6 @@
#include "exynos-pmu.h"
-struct exynos_pmu_context {
- struct device *dev;
- const struct exynos_pmu_data *pmu_data;
- struct regmap *pmureg;
- struct regmap *pmuintrgen;
- /*
- * Serialization lock for CPU hot plug and cpuidle ACPM hint
- * programming. Also protects in_cpuhp, sys_insuspend & sys_inreboot
- * flags.
- */
- raw_spinlock_t cpupm_lock;
- unsigned long *in_cpuhp;
- bool sys_insuspend;
- bool sys_inreboot;
- int cpuhp_prepare_state;
- int cpuhp_online_state;
-};
-
void __iomem *pmu_base_addr;
static struct exynos_pmu_context *pmu_context;
/* forward declaration */
@@ -221,44 +203,8 @@ struct regmap *exynos_get_pmu_regmap_by_phandle(struct device_node *np,
}
EXPORT_SYMBOL_GPL(exynos_get_pmu_regmap_by_phandle);
-/*
- * CPU_INFORM register "hint" values are required to be programmed in addition to
- * the standard PSCI calls to have functional CPU hotplug and CPU idle states.
- * This is required to workaround limitations in the el3mon/ACPM firmware.
- */
-#define CPU_INFORM_CLEAR 0
-#define CPU_INFORM_C2 1
-
-/*
- * __gs101_cpu_pmu_ prefix functions are common code shared by CPU PM notifiers
- * (CPUIdle) and CPU hotplug callbacks. Functions should be called with IRQs
- * disabled and cpupm_lock held.
- */
-static int __gs101_cpu_pmu_online(unsigned int cpu)
- __must_hold(&pmu_context->cpupm_lock)
-{
- unsigned int cpuhint = smp_processor_id();
- u32 reg, mask;
-
- /* clear cpu inform hint */
- regmap_write(pmu_context->pmureg, GS101_CPU_INFORM(cpuhint),
- CPU_INFORM_CLEAR);
-
- mask = BIT(cpu);
-
- regmap_update_bits(pmu_context->pmuintrgen, GS101_GRP2_INTR_BID_ENABLE,
- mask, (0 << cpu));
-
- regmap_read(pmu_context->pmuintrgen, GS101_GRP2_INTR_BID_UPEND, ®);
-
- regmap_write(pmu_context->pmuintrgen, GS101_GRP2_INTR_BID_CLEAR,
- reg & mask);
-
- return 0;
-}
-
/* Called from CPU PM notifier (CPUIdle code path) with IRQs disabled */
-static int gs101_cpu_pmu_online(void)
+static int exynos_cpu_pmu_online(void)
{
int cpu;
@@ -270,20 +216,20 @@ static int gs101_cpu_pmu_online(void)
}
cpu = smp_processor_id();
- __gs101_cpu_pmu_online(cpu);
+ pmu_context->pmu_data->cpu_pmu_online(pmu_context, cpu);
raw_spin_unlock(&pmu_context->cpupm_lock);
return NOTIFY_OK;
}
/* Called from CPU hot plug callback with IRQs enabled */
-static int gs101_cpuhp_pmu_online(unsigned int cpu)
+static int exynos_cpuhp_pmu_online(unsigned int cpu)
{
unsigned long flags;
raw_spin_lock_irqsave(&pmu_context->cpupm_lock, flags);
- __gs101_cpu_pmu_online(cpu);
+ pmu_context->pmu_data->cpu_pmu_online(pmu_context, cpu);
/*
* Mark this CPU as having finished the hotplug.
* This means this CPU can now enter C2 idle state.
@@ -294,35 +240,8 @@ static int gs101_cpuhp_pmu_online(unsigned int cpu)
return 0;
}
-/* Common function shared by both CPU hot plug and CPUIdle */
-static int __gs101_cpu_pmu_offline(unsigned int cpu)
- __must_hold(&pmu_context->cpupm_lock)
-{
- unsigned int cpuhint = smp_processor_id();
- u32 reg, mask;
-
- /* set cpu inform hint */
- regmap_write(pmu_context->pmureg, GS101_CPU_INFORM(cpuhint),
- CPU_INFORM_C2);
-
- mask = BIT(cpu);
- regmap_update_bits(pmu_context->pmuintrgen, GS101_GRP2_INTR_BID_ENABLE,
- mask, BIT(cpu));
-
- regmap_read(pmu_context->pmuintrgen, GS101_GRP1_INTR_BID_UPEND, ®);
- regmap_write(pmu_context->pmuintrgen, GS101_GRP1_INTR_BID_CLEAR,
- reg & mask);
-
- mask = (BIT(cpu + 8));
- regmap_read(pmu_context->pmuintrgen, GS101_GRP1_INTR_BID_UPEND, ®);
- regmap_write(pmu_context->pmuintrgen, GS101_GRP1_INTR_BID_CLEAR,
- reg & mask);
-
- return 0;
-}
-
/* Called from CPU PM notifier (CPUIdle code path) with IRQs disabled */
-static int gs101_cpu_pmu_offline(void)
+static int exynos_cpu_pmu_offline(void)
{
int cpu;
@@ -340,14 +259,14 @@ static int gs101_cpu_pmu_offline(void)
return NOTIFY_OK;
}
- __gs101_cpu_pmu_offline(cpu);
+ pmu_context->pmu_data->cpu_pmu_offline(pmu_context, cpu);
raw_spin_unlock(&pmu_context->cpupm_lock);
return NOTIFY_OK;
}
/* Called from CPU hot plug callback with IRQs enabled */
-static int gs101_cpuhp_pmu_offline(unsigned int cpu)
+static int exynos_cpuhp_pmu_offline(unsigned int cpu)
{
unsigned long flags;
@@ -357,29 +276,29 @@ static int gs101_cpuhp_pmu_offline(unsigned int cpu)
* ACPM the CPU entering hotplug should not enter C2 idle state.
*/
set_bit(cpu, pmu_context->in_cpuhp);
- __gs101_cpu_pmu_offline(cpu);
+ pmu_context->pmu_data->cpu_pmu_offline(pmu_context, cpu);
raw_spin_unlock_irqrestore(&pmu_context->cpupm_lock, flags);
return 0;
}
-static int gs101_cpu_pm_notify_callback(struct notifier_block *self,
+static int exynos_cpu_pm_notify_callback(struct notifier_block *self,
unsigned long action, void *v)
{
switch (action) {
case CPU_PM_ENTER:
- return gs101_cpu_pmu_offline();
+ return exynos_cpu_pmu_offline();
case CPU_PM_EXIT:
- return gs101_cpu_pmu_online();
+ return exynos_cpu_pmu_online();
}
return NOTIFY_OK;
}
-static struct notifier_block gs101_cpu_pm_notifier = {
- .notifier_call = gs101_cpu_pm_notify_callback,
+static struct notifier_block exynos_cpu_pm_notifier = {
+ .notifier_call = exynos_cpu_pm_notify_callback,
/*
* We want to be called first, as the ACPM hint and handshake is what
* puts the CPU into C2.
@@ -417,6 +336,12 @@ static int setup_cpuhp_and_cpuidle(struct device *dev)
void __iomem *virt_addr;
int ret, cpu;
+ if (!pmu_context->pmu_data->cpu_pmu_offline || !pmu_context->pmu_data->cpu_pmu_online) {
+ dev_warn(dev,
+ "PMU write/update sequence is not present for cpuhotplug and cpuidle\n");
+ return 0;
+ }
+
if (!intr_gen_node) {
/*
* To maintain support for older DTs that didn't specify syscon
@@ -457,28 +382,28 @@ static int setup_cpuhp_and_cpuidle(struct device *dev)
/* set PMU to power on */
for_each_online_cpu(cpu)
- gs101_cpuhp_pmu_online(cpu);
+ exynos_cpuhp_pmu_online(cpu);
/* register CPU hotplug callbacks */
pmu_context->cpuhp_prepare_state = CPUHP_INVALID;
pmu_context->cpuhp_online_state = CPUHP_INVALID;
ret = cpuhp_setup_state(CPUHP_BP_PREPARE_DYN, "soc/exynos-pmu:prepare",
- gs101_cpuhp_pmu_online, NULL);
+ exynos_cpuhp_pmu_online, NULL);
if (ret < 0)
return ret;
pmu_context->cpuhp_prepare_state = ret;
ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "soc/exynos-pmu:online",
- NULL, gs101_cpuhp_pmu_offline);
+ NULL, exynos_cpuhp_pmu_offline);
if (ret < 0)
goto clean_cpuhp_state_prepare;
pmu_context->cpuhp_online_state = ret;
/* register CPU PM notifiers for cpuidle */
- ret = cpu_pm_register_notifier(&gs101_cpu_pm_notifier);
+ ret = cpu_pm_register_notifier(&exynos_cpu_pm_notifier);
if (ret)
goto clean_cpuhp_states;
@@ -487,7 +412,7 @@ static int setup_cpuhp_and_cpuidle(struct device *dev)
/* Success */
return ret;
- cpu_pm_unregister_notifier(&gs101_cpu_pm_notifier);
+ cpu_pm_unregister_notifier(&exynos_cpu_pm_notifier);
clean_cpuhp_states:
cpuhp_remove_state(pmu_context->cpuhp_online_state);
@@ -502,7 +427,7 @@ static int setup_cpuhp_and_cpuidle(struct device *dev)
static void destroy_cpuhp_and_cpuidle(void)
{
- cpu_pm_unregister_notifier(&gs101_cpu_pm_notifier);
+ cpu_pm_unregister_notifier(&exynos_cpu_pm_notifier);
unregister_reboot_notifier(&exynos_cpupm_reboot_nb);
if (pmu_context->cpuhp_prepare_state != CPUHP_INVALID)
diff --git a/drivers/soc/samsung/exynos-pmu.h b/drivers/soc/samsung/exynos-pmu.h
index fbe381e2a2e1..733e188fa2b1 100644
--- a/drivers/soc/samsung/exynos-pmu.h
+++ b/drivers/soc/samsung/exynos-pmu.h
@@ -13,6 +13,14 @@
#define PMU_TABLE_END (-1U)
+/*
+ * CPU_INFORM register "hint" values are required to be programmed in addition to
+ * the standard PSCI calls to have functional CPU hotplug and CPU idle states.
+ * This is required to workaround limitations in the el3mon/ACPM firmware.
+ */
+#define CPU_INFORM_CLEAR 0
+#define CPU_INFORM_C2 1
+
struct regmap_access_table;
struct exynos_pmu_conf {
@@ -20,6 +28,24 @@ struct exynos_pmu_conf {
u8 val[NUM_SYS_POWERDOWN];
};
+struct exynos_pmu_context {
+ struct device *dev;
+ const struct exynos_pmu_data *pmu_data;
+ struct regmap *pmureg;
+ struct regmap *pmuintrgen;
+ /*
+ * Serialization lock for CPU hot plug and cpuidle ACPM hint
+ * programming. Also protects in_cpuhp, sys_insuspend & sys_inreboot
+ * flags.
+ */
+ raw_spinlock_t cpupm_lock;
+ unsigned long *in_cpuhp;
+ bool sys_insuspend;
+ bool sys_inreboot;
+ int cpuhp_prepare_state;
+ int cpuhp_online_state;
+};
+
/**
* struct exynos_pmu_data - of_device_id (match) data
*
@@ -44,6 +70,10 @@ struct exynos_pmu_conf {
* used (i.e. when @pmu_secure is @true).
* @wr_table: A table of writable register ranges in case a custom regmap is
* used (i.e. when @pmu_secure is @true).
+ * @cpu_pmu_offline: Optional callback to be called before entering CPU offline
+ * or idle state. Only valid when pmu_cpuhp set to true.
+ * @cpu_pmu_online: Optional callback to be called after CPU onlined or after
+ * exiting idle state. Only valid when pmu_cpuhp set to true.
*/
struct exynos_pmu_data {
const struct exynos_pmu_conf *pmu_config;
@@ -57,6 +87,9 @@ struct exynos_pmu_data {
const struct regmap_access_table *rd_table;
const struct regmap_access_table *wr_table;
+
+ int (*cpu_pmu_offline)(struct exynos_pmu_context *pmu_context, unsigned int cpu);
+ int (*cpu_pmu_online)(struct exynos_pmu_context *pmu_context, unsigned int cpu);
};
extern void __iomem *pmu_base_addr;
diff --git a/drivers/soc/samsung/gs101-pmu.c b/drivers/soc/samsung/gs101-pmu.c
index 17dadc1b9c6e..ee7897eed20a 100644
--- a/drivers/soc/samsung/gs101-pmu.c
+++ b/drivers/soc/samsung/gs101-pmu.c
@@ -322,11 +322,62 @@ static const struct regmap_access_table gs101_pmu_wr_table = {
.n_no_ranges = ARRAY_SIZE(gs101_pmu_ro_registers),
};
+/*
+ * gs101_cpu_pmu_ prefix functions are common code shared by CPU PM notifiers
+ * (CPUIdle) and CPU hotplug callbacks. Functions should be called with IRQs
+ * disabled and cpupm_lock held.
+ */
+static int gs101_cpu_pmu_online(struct exynos_pmu_context *pmu_context, unsigned int cpu)
+ __must_hold(&pmu_context->cpupm_lock)
+{
+ unsigned int cpuhint = smp_processor_id();
+ u32 reg, mask;
+
+ /* clear cpu inform hint */
+ regmap_write(pmu_context->pmureg, GS101_CPU_INFORM(cpuhint), 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);
+
+ return 0;
+}
+
+/* Common function shared by both CPU hot plug and CPUIdle */
+static int gs101_cpu_pmu_offline(struct exynos_pmu_context *pmu_context, unsigned int cpu)
+ __must_hold(&pmu_context->cpupm_lock)
+{
+ unsigned int cpuhint = smp_processor_id();
+ u32 reg, mask;
+
+ /* set cpu inform hint */
+ regmap_write(pmu_context->pmureg, GS101_CPU_INFORM(cpuhint), 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);
+
+ return 0;
+}
+
const struct exynos_pmu_data gs101_pmu_data = {
.pmu_secure = true,
.pmu_cpuhp = true,
.rd_table = &gs101_pmu_rd_table,
.wr_table = &gs101_pmu_wr_table,
+ .cpu_pmu_offline = gs101_cpu_pmu_offline,
+ .cpu_pmu_online = gs101_cpu_pmu_online,
};
/*
diff --git a/include/linux/soc/samsung/exynos-regs-pmu.h b/include/linux/soc/samsung/exynos-regs-pmu.h
index db8a7ca81080..9c4d3da41dbf 100644
--- a/include/linux/soc/samsung/exynos-regs-pmu.h
+++ b/include/linux/soc/samsung/exynos-regs-pmu.h
@@ -1009,11 +1009,11 @@
#define GS101_PHY_CTRL_UFS 0x3ec8
/* PMU INTR GEN */
-#define GS101_GRP1_INTR_BID_UPEND (0x0108)
-#define GS101_GRP1_INTR_BID_CLEAR (0x010c)
-#define GS101_GRP2_INTR_BID_ENABLE (0x0200)
-#define GS101_GRP2_INTR_BID_UPEND (0x0208)
-#define GS101_GRP2_INTR_BID_CLEAR (0x020c)
+#define EXYNOS_GRP1_INTR_BID_UPEND (0x0108)
+#define EXYNOS_GRP1_INTR_BID_CLEAR (0x010c)
+#define EXYNOS_GRP2_INTR_BID_ENABLE (0x0200)
+#define EXYNOS_GRP2_INTR_BID_UPEND (0x0208)
+#define EXYNOS_GRP2_INTR_BID_CLEAR (0x020c)
/* exynosautov920 */
#define EXYNOSAUTOV920_PHY_CTRL_USB20 (0x0710)
--
2.51.0
^ permalink raw reply [flat|nested] 11+ messages in thread* [PATCH v7 4/6] soc: samsung: exynos-pmu: add Exynos850 CPU hotplug support
2026-09-30 0:12 [PATCH v7 0/6] Exynos-pmu: Generalise cpu{hotplug,idle},PMU intr gen and add Exynos850 CPU hotplug Alexey Klimov
` (2 preceding siblings ...)
2026-09-30 0:12 ` [PATCH v7 3/6] soc: samsung: exynos-pmu: generalise gs101-specific cpu{idle,hotplug} for Exynos SoCs Alexey Klimov
@ 2026-09-30 0:12 ` Alexey Klimov
2026-10-03 14:20 ` Krzysztof Kozlowski
2026-09-30 0:13 ` [PATCH v7 5/6] MAINTAINERS: add Exynos850 PMU entry Alexey Klimov
2026-09-30 0:13 ` [PATCH v7 6/6] arm64: dts: exynos850: add PMU interrupt generation node Alexey Klimov
5 siblings, 1 reply; 11+ messages in thread
From: Alexey Klimov @ 2026-09-30 0:12 UTC (permalink / raw)
To: Sam Protsenko, linux-samsung-soc, Krzysztof Kozlowski, Peter Griffin
Cc: André Draszik, Tudor Ambarus, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Alim Akhtar, Henrik Grimler,
linux-arm-kernel, devicetree, linux-kernel
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@linaro.org>
---
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 9efaaf4696cf..387ed149fa71 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*/ },
};
@@ -480,6 +489,21 @@ 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
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH v7 4/6] soc: samsung: exynos-pmu: add Exynos850 CPU hotplug support
2026-09-30 0:12 ` [PATCH v7 4/6] soc: samsung: exynos-pmu: add Exynos850 CPU hotplug support Alexey Klimov
@ 2026-10-03 14:20 ` Krzysztof Kozlowski
0 siblings, 0 replies; 11+ messages in thread
From: Krzysztof Kozlowski @ 2026-10-03 14:20 UTC (permalink / raw)
To: Alexey Klimov, Sam Protsenko, linux-samsung-soc, Peter Griffin
Cc: André Draszik, Tudor Ambarus, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Alim Akhtar, Henrik Grimler,
linux-arm-kernel, devicetree, linux-kernel
On 30/09/2026 02:12, Alexey Klimov wrote:
> Add cpuhotplug support for Exynos850 platforms. This SoC requires
Since I expect v8 due to DTS change, one nit below.
> /* 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;
Before gs101. Don't add to the end of such lists.
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH v7 5/6] MAINTAINERS: add Exynos850 PMU entry
2026-09-30 0:12 [PATCH v7 0/6] Exynos-pmu: Generalise cpu{hotplug,idle},PMU intr gen and add Exynos850 CPU hotplug Alexey Klimov
` (3 preceding siblings ...)
2026-09-30 0:12 ` [PATCH v7 4/6] soc: samsung: exynos-pmu: add Exynos850 CPU hotplug support Alexey Klimov
@ 2026-09-30 0:13 ` Alexey Klimov
2026-09-30 0:13 ` [PATCH v7 6/6] arm64: dts: exynos850: add PMU interrupt generation node Alexey Klimov
5 siblings, 0 replies; 11+ messages in thread
From: Alexey Klimov @ 2026-09-30 0:13 UTC (permalink / raw)
To: Sam Protsenko, linux-samsung-soc, Krzysztof Kozlowski, Peter Griffin
Cc: André Draszik, Tudor Ambarus, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Alim Akhtar, Henrik Grimler,
linux-arm-kernel, devicetree, linux-kernel
Add Exynos850 PMU entry describing new file
drivers/soc/samsung/exynos850-pmu.c.
Add myself as M there since I contributed Exynos850
PMU support and intend to maintain that.
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 137297bf508b..810111c83478 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -24622,6 +24622,13 @@ F: arch/arm64/boot/dts/exynos/exynos2200*
F: drivers/clk/samsung/clk-exynos2200.c
F: include/dt-bindings/clock/samsung,exynos2200-cmu.h
+SAMSUNG EXYNOS850 PMU SUPPORT
+M: Alexey Klimov <alexey.klimov@linaro.org>
+L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
+L: linux-samsung-soc@vger.kernel.org
+S: Maintained
+F: drivers/soc/samsung/exynos850-pmu.c
+
SAMSUNG EXYNOS850 SoC SUPPORT
M: Sam Protsenko <semen.protsenko@linaro.org>
L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
--
2.51.0
^ permalink raw reply [flat|nested] 11+ messages in thread* [PATCH v7 6/6] arm64: dts: exynos850: add PMU interrupt generation node
2026-09-30 0:12 [PATCH v7 0/6] Exynos-pmu: Generalise cpu{hotplug,idle},PMU intr gen and add Exynos850 CPU hotplug Alexey Klimov
` (4 preceding siblings ...)
2026-09-30 0:13 ` [PATCH v7 5/6] MAINTAINERS: add Exynos850 PMU entry Alexey Klimov
@ 2026-09-30 0:13 ` Alexey Klimov
2026-10-02 12:41 ` Peter Griffin
5 siblings, 1 reply; 11+ messages in thread
From: Alexey Klimov @ 2026-09-30 0:13 UTC (permalink / raw)
To: Sam Protsenko, linux-samsung-soc, Krzysztof Kozlowski, Peter Griffin
Cc: André Draszik, Tudor Ambarus, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Alim Akhtar, Henrik Grimler,
linux-arm-kernel, devicetree, linux-kernel
Add pmu_intr_gen node for Exynos850. This hw block is required
for different power management routines like CPU hotplug and
different sleep and idle states.
Also reference this node from main PMU node.
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
---
arch/arm64/boot/dts/exynos/exynos850.dtsi | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/arm64/boot/dts/exynos/exynos850.dtsi b/arch/arm64/boot/dts/exynos/exynos850.dtsi
index 8a4771899a8e..803fc127d895 100644
--- a/arch/arm64/boot/dts/exynos/exynos850.dtsi
+++ b/arch/arm64/boot/dts/exynos/exynos850.dtsi
@@ -231,6 +231,7 @@ gic: interrupt-controller@12a01000 {
pmu_system_controller: system-controller@11860000 {
compatible = "samsung,exynos850-pmu", "syscon";
reg = <0x11860000 0x10000>;
+ google,pmu-intr-gen-syscon = <&pmu_intr_gen>;
poweroff: syscon-poweroff {
compatible = "syscon-poweroff";
@@ -248,6 +249,11 @@ reboot: syscon-reboot {
};
};
+ pmu_intr_gen: syscon@11870000 {
+ compatible = "samsung,exynos850-pmu-intr-gen", "syscon";
+ reg = <0x11870000 0x10000>;
+ };
+
watchdog_cl0: watchdog@10050000 {
compatible = "samsung,exynos850-wdt";
reg = <0x10050000 0x100>;
--
2.51.0
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH v7 6/6] arm64: dts: exynos850: add PMU interrupt generation node
2026-09-30 0:13 ` [PATCH v7 6/6] arm64: dts: exynos850: add PMU interrupt generation node Alexey Klimov
@ 2026-10-02 12:41 ` Peter Griffin
2026-10-03 14:13 ` Krzysztof Kozlowski
0 siblings, 1 reply; 11+ messages in thread
From: Peter Griffin @ 2026-10-02 12:41 UTC (permalink / raw)
To: Alexey Klimov
Cc: Sam Protsenko, linux-samsung-soc, Krzysztof Kozlowski,
André Draszik, Tudor Ambarus, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Alim Akhtar, Henrik Grimler,
linux-arm-kernel, devicetree, linux-kernel
Hi Alexey,
On Wed, 30 Sept 2026 at 01:13, Alexey Klimov <alexey.klimov@linaro.org> wrote:
>
> Add pmu_intr_gen node for Exynos850. This hw block is required
> for different power management routines like CPU hotplug and
> different sleep and idle states.
> Also reference this node from main PMU node.
>
> Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
> Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
> ---
> arch/arm64/boot/dts/exynos/exynos850.dtsi | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/exynos/exynos850.dtsi b/arch/arm64/boot/dts/exynos/exynos850.dtsi
> index 8a4771899a8e..803fc127d895 100644
> --- a/arch/arm64/boot/dts/exynos/exynos850.dtsi
> +++ b/arch/arm64/boot/dts/exynos/exynos850.dtsi
> @@ -231,6 +231,7 @@ gic: interrupt-controller@12a01000 {
> pmu_system_controller: system-controller@11860000 {
> compatible = "samsung,exynos850-pmu", "syscon";
> reg = <0x11860000 0x10000>;
> + google,pmu-intr-gen-syscon = <&pmu_intr_gen>;
>
> poweroff: syscon-poweroff {
> compatible = "syscon-poweroff";
> @@ -248,6 +249,11 @@ reboot: syscon-reboot {
> };
> };
>
> + pmu_intr_gen: syscon@11870000 {
> + compatible = "samsung,exynos850-pmu-intr-gen", "syscon";
> + reg = <0x11870000 0x10000>;
> + };
> +
Since you are now creating your own custom regmap in exynos-pmu you
should drop the syscon compatible here. That should avoid syscon.c
ever creating an MMIO regmap (with the wrong spinlock). I've copied
some of the commit text from my commit
a21d38b5e209c60e73f81e467cc53ad57b5d4080 below for the rationale
behind this.
arm64: dts: exynos: gs101: remove syscon compatible from pmu node
Since commit ba5095ebbc7a ("mfd: syscon: Allow syscon nodes without a
"syscon" compatible") it is possible to register a regmap without the
syscon compatible in the node.
As mentioned in that commit, it's not correct to claim we are compatible
with syscon, as a MMIO regmap created by syscon won't work. Removing the
syscon compatible means syscon driver won't ever create a mmio regmap.
Note this isn't usually an issue today as exynos-pmu runs at an early
initcall so the custom regmap will have been registered first. However
changes proposed in [1] will bring -EPROBE_DEFER support to syscon allowing
this mechanism to be more robust, especially in highly modularized systems.
Technically this is a ABI break but no other platforms are
affected. Additionally (with the benefit of hindsight) a MMIO syscon has
never worked for PMU register writes, thus the ABI break is justified.
Link: https://lore.kernel.org/lkml/aQdHmrchkmOr34r3@stanley.mountain/ [1]
Thanks,
Peter
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH v7 6/6] arm64: dts: exynos850: add PMU interrupt generation node
2026-10-02 12:41 ` Peter Griffin
@ 2026-10-03 14:13 ` Krzysztof Kozlowski
2026-10-03 14:15 ` Krzysztof Kozlowski
0 siblings, 1 reply; 11+ messages in thread
From: Krzysztof Kozlowski @ 2026-10-03 14:13 UTC (permalink / raw)
To: Peter Griffin, Alexey Klimov
Cc: Sam Protsenko, linux-samsung-soc, André Draszik,
Tudor Ambarus, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
Alim Akhtar, Henrik Grimler, linux-arm-kernel, devicetree,
linux-kernel
On 02/10/2026 14:41, Peter Griffin wrote:
>>
>> + pmu_intr_gen: syscon@11870000 {
>> + compatible = "samsung,exynos850-pmu-intr-gen", "syscon";
>> + reg = <0x11870000 0x10000>;
>> + };
>> +
>
> Since you are now creating your own custom regmap in exynos-pmu you
> should drop the syscon compatible here. That should avoid syscon.c
> ever creating an MMIO regmap (with the wrong spinlock). I've copied
> some of the commit text from my commit
Yes, there should be no syscon fallback.
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH v7 6/6] arm64: dts: exynos850: add PMU interrupt generation node
2026-10-03 14:13 ` Krzysztof Kozlowski
@ 2026-10-03 14:15 ` Krzysztof Kozlowski
0 siblings, 0 replies; 11+ messages in thread
From: Krzysztof Kozlowski @ 2026-10-03 14:15 UTC (permalink / raw)
To: Peter Griffin, Alexey Klimov
Cc: Sam Protsenko, linux-samsung-soc, André Draszik,
Tudor Ambarus, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
Alim Akhtar, Henrik Grimler, linux-arm-kernel, devicetree,
linux-kernel
On 03/10/2026 16:13, Krzysztof Kozlowski wrote:
> On 02/10/2026 14:41, Peter Griffin wrote:
>>>
>>> + pmu_intr_gen: syscon@11870000 {
>>> + compatible = "samsung,exynos850-pmu-intr-gen", "syscon";
>>> + reg = <0x11870000 0x10000>;
>>> + };
>>> +
>>
>> Since you are now creating your own custom regmap in exynos-pmu you
>> should drop the syscon compatible here. That should avoid syscon.c
>> ever creating an MMIO regmap (with the wrong spinlock). I've copied
>> some of the commit text from my commit
>
> Yes, there should be no syscon fallback.
... although not here, but for existing PMU node.
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 11+ messages in thread