[PATCH v3 0/4] MT8196 CPUFreq Support

[PATCH v3 0/4] MT8196 CPUFreq Support

[Nicolas Frattaroli]

This series adds the necessary bindings and driver changes to integrate
MT8196 CPUFreq into the existing mediatek-cpufreq-hw driver. This
necessitated two preparatory cleanup patches to the driver.

The CPU frequency was verified to actually be changing by comparing
sysbench cpu numbers between fdvfs being enabled and it not being
enabled.

Enablement in the DT will be done once the MT8196 DT lands, so don't be
surprised that no node uses these new compatibles so far.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
---
Changes in v3:
- bindings: changed title as per angelo's suggestions
- bindings: dropped the fdvfs magic register range
- bindings: dropped redundant description for #performance-domain-cells
- driver: made fdvfs frequency divisor a `#define` instead of part of
  the variant struct
- driver: dropped fdvfs magic check
- driver: reworked performance domain resource offset
- Link to v2: https://lore.kernel.org/r/20250714-mt8196-cpufreq-v2-0-cc85e78855c7@collabora.com

Changes in v2:
- Split off mt8196-cpufreq-hw into a new binding.
- Made the fdvfs register regions part of the cpufreq "performance"
  node, instead of using syscons for this.
- Adjusted the driver to iomap those, and use the per-variant struct to
  add an offset for the domains index.
- Link to v1: https://lore.kernel.org/r/20250711-mt8196-cpufreq-v1-0-e1b0a3b4ac61@collabora.com

---
Nicolas Frattaroli (4):
      dt-bindings: cpufreq: Add mediatek,mt8196-cpufreq-hw binding
      cpufreq: mediatek-hw: Refactor match data into struct
      cpufreq: mediatek-hw: Separate per-domain and per-instance data
      cpufreq: mediatek-hw: Add support for MT8196

 .../cpufreq/mediatek,mt8196-cpufreq-hw.yaml        |  82 +++++++++++++
 drivers/cpufreq/mediatek-cpufreq-hw.c              | 134 +++++++++++++++++----
 2 files changed, 192 insertions(+), 24 deletions(-)
---
base-commit: 4d088c49d1e49e0149aa66908c3e8722af68ed07
change-id: 20250711-mt8196-cpufreq-86d961e2300b

Best regards,
-- 
Nicolas Frattaroli <nicolas.frattaroli@collabora.com>

[PATCH v3 1/4] dt-bindings: cpufreq: Add mediatek,mt8196-cpufreq-hw binding

[Nicolas Frattaroli]

The MediaTek MT8196 SoC has new cpufreq hardware, with added memory
register ranges to control Dynamic-Voltage-Frequency-Scaling.

The DVFS hardware is controlled through a set of registers referred to
as "FDVFS". They set the target frequency the DVFS hardware should aim
for for each performance domain.

Instead of working around the old binding and its already established
meanings for the reg items, add a new binding. The FDVFS register memory
region is at the beginning, which allows us to easily expand this
binding for future SoCs which may have more than 3 performance domains.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
---
 .../cpufreq/mediatek,mt8196-cpufreq-hw.yaml        | 82 ++++++++++++++++++++++
 1 file changed, 82 insertions(+)

diff --git a/Documentation/devicetree/bindings/cpufreq/mediatek,mt8196-cpufreq-hw.yaml b/Documentation/devicetree/bindings/cpufreq/mediatek,mt8196-cpufreq-hw.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..5f3c7db3f3aa0abf90061b2d735f975135cb35eb
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/mediatek,mt8196-cpufreq-hw.yaml
@@ -0,0 +1,82 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/cpufreq/mediatek,mt8196-cpufreq-hw.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek Hybrid CPUFreq for MT8196/MT6991 series SoCs
+
+maintainers:
+  - Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
+
+description:
+  MT8196 uses CPUFreq management hardware that supports dynamic voltage
+  frequency scaling (dvfs), and can support several performance domains.
+
+properties:
+  compatible:
+    const: mediatek,mt8196-cpufreq-hw
+
+  reg:
+    items:
+      - description: FDVFS control register region
+      - description: OPP tables and control for performance domain 0
+      - description: OPP tables and control for performance domain 1
+      - description: OPP tables and control for performance domain 2
+
+  "#performance-domain-cells":
+    const: 1
+
+required:
+  - compatible
+  - reg
+  - "#performance-domain-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    cpus {
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            cpu0: cpu@0 {
+                device_type = "cpu";
+                compatible = "arm,cortex-a720";
+                enable-method = "psci";
+                performance-domains = <&performance 0>;
+                reg = <0x000>;
+            };
+
+            /* ... */
+
+            cpu6: cpu@600 {
+                device_type = "cpu";
+                compatible = "arm,cortex-x4";
+                enable-method = "psci";
+                performance-domains = <&performance 1>;
+                reg = <0x600>;
+            };
+
+            cpu7: cpu@700 {
+                device_type = "cpu";
+                compatible = "arm,cortex-x925";
+                enable-method = "psci";
+                performance-domains = <&performance 2>;
+                reg = <0x700>;
+            };
+    };
+
+    /* ... */
+
+    soc {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        performance: performance-controller@c2c2034 {
+            compatible = "mediatek,mt8196-cpufreq-hw";
+            reg = <0 0xc220400 0 0x20>, <0 0xc2c0f20 0 0x120>,
+                  <0 0xc2c1040 0 0x120>, <0 0xc2c1160 0 0x120>;
+            #performance-domain-cells = <1>;
+        };
+    };

-- 
2.50.1

Re: [PATCH v3 1/4] dt-bindings: cpufreq: Add mediatek,mt8196-cpufreq-hw binding

[AngeloGioacchino Del Regno]

Il 16/07/25 19:51, Nicolas Frattaroli ha scritto:
> The MediaTek MT8196 SoC has new cpufreq hardware, with added memory
> register ranges to control Dynamic-Voltage-Frequency-Scaling.
> 
> The DVFS hardware is controlled through a set of registers referred to
> as "FDVFS". They set the target frequency the DVFS hardware should aim
> for for each performance domain.
> 
> Instead of working around the old binding and its already established
> meanings for the reg items, add a new binding. The FDVFS register memory
> region is at the beginning, which allows us to easily expand this
> binding for future SoCs which may have more than 3 performance domains.
> 
> Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Re: [PATCH v3 1/4] dt-bindings: cpufreq: Add mediatek,mt8196-cpufreq-hw binding

[Rob Herring (Arm)]

On Wed, 16 Jul 2025 19:51:22 +0200, Nicolas Frattaroli wrote:
> The MediaTek MT8196 SoC has new cpufreq hardware, with added memory
> register ranges to control Dynamic-Voltage-Frequency-Scaling.
> 
> The DVFS hardware is controlled through a set of registers referred to
> as "FDVFS". They set the target frequency the DVFS hardware should aim
> for for each performance domain.
> 
> Instead of working around the old binding and its already established
> meanings for the reg items, add a new binding. The FDVFS register memory
> region is at the beginning, which allows us to easily expand this
> binding for future SoCs which may have more than 3 performance domains.
> 
> Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
> ---
>  .../cpufreq/mediatek,mt8196-cpufreq-hw.yaml        | 82 ++++++++++++++++++++++
>  1 file changed, 82 insertions(+)
> 

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>

[PATCH v3 2/4] cpufreq: mediatek-hw: Refactor match data into struct

[Nicolas Frattaroli]

While the driver could get away with having the per-compatible match
data just be an array of the reg offsets, the only thing it used it for
right now, this doesn't really allow it to be extended in any meaningful
way if some other per-variant information needs to be communicated.

In preparation of adding support for hybrid "FDVFS" for MT8196, refactor
the code to make the DT match data a struct, which currently only
contains a single member: the reg offsets. This will allow this struct
to be extended with other members for other hardware variants.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
---
 drivers/cpufreq/mediatek-cpufreq-hw.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/drivers/cpufreq/mediatek-cpufreq-hw.c b/drivers/cpufreq/mediatek-cpufreq-hw.c
index 74f1b4c796e4cc9ebccf50dd4e165a1eba03136a..b2aba1842226c7d24a8b9599ea62408cac9f803c 100644
--- a/drivers/cpufreq/mediatek-cpufreq-hw.c
+++ b/drivers/cpufreq/mediatek-cpufreq-hw.c
@@ -41,15 +41,22 @@ struct mtk_cpufreq_data {
 	struct resource *res;
 	void __iomem *base;
 	int nr_opp;
+	const struct mtk_cpufreq_variant *variant;
 };
 
-static const u16 cpufreq_mtk_offsets[REG_ARRAY_SIZE] = {
-	[REG_FREQ_LUT_TABLE]	= 0x0,
-	[REG_FREQ_ENABLE]	= 0x84,
-	[REG_FREQ_PERF_STATE]	= 0x88,
-	[REG_FREQ_HW_STATE]	= 0x8c,
-	[REG_EM_POWER_TBL]	= 0x90,
-	[REG_FREQ_LATENCY]	= 0x110,
+struct mtk_cpufreq_variant {
+	const u16 reg_offsets[REG_ARRAY_SIZE];
+};
+
+static const struct mtk_cpufreq_variant cpufreq_mtk_base_variant = {
+	.reg_offsets = {
+		[REG_FREQ_LUT_TABLE]	= 0x0,
+		[REG_FREQ_ENABLE]	= 0x84,
+		[REG_FREQ_PERF_STATE]	= 0x88,
+		[REG_FREQ_HW_STATE]	= 0x8c,
+		[REG_EM_POWER_TBL]	= 0x90,
+		[REG_FREQ_LATENCY]	= 0x110,
+	},
 };
 
 static int __maybe_unused
@@ -157,7 +164,7 @@ static int mtk_cpu_create_freq_table(struct platform_device *pdev,
 
 static int mtk_cpu_resources_init(struct platform_device *pdev,
 				  struct cpufreq_policy *policy,
-				  const u16 *offsets)
+				  const struct mtk_cpufreq_variant *variant)
 {
 	struct mtk_cpufreq_data *data;
 	struct device *dev = &pdev->dev;
@@ -200,9 +207,10 @@ static int mtk_cpu_resources_init(struct platform_device *pdev,
 
 	data->base = base;
 	data->res = res;
+	data->variant = variant;
 
 	for (i = REG_FREQ_LUT_TABLE; i < REG_ARRAY_SIZE; i++)
-		data->reg_bases[i] = base + offsets[i];
+		data->reg_bases[i] = base + variant->reg_offsets[i];
 
 	ret = mtk_cpu_create_freq_table(pdev, data);
 	if (ret) {
@@ -336,7 +344,7 @@ static void mtk_cpufreq_hw_driver_remove(struct platform_device *pdev)
 }
 
 static const struct of_device_id mtk_cpufreq_hw_match[] = {
-	{ .compatible = "mediatek,cpufreq-hw", .data = &cpufreq_mtk_offsets },
+	{ .compatible = "mediatek,cpufreq-hw", .data = &cpufreq_mtk_base_variant },
 	{}
 };
 MODULE_DEVICE_TABLE(of, mtk_cpufreq_hw_match);

-- 
2.50.1

[PATCH v3 3/4] cpufreq: mediatek-hw: Separate per-domain and per-instance data

[Nicolas Frattaroli]

As it stood, the mediatek cpufreq driver could get away with never
really having a private driver instance struct. This is because all data
was stored in the per-domain structs.

However, this complicates matters when actual per-instance data like the
variant struct is introduced. Instead of having a pointer to it for
every domain, have a pointer to a global "priv" struct that can be
extended over time, and rename the "data" struct to "domain" to
distinguish its purpose better.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
---
 drivers/cpufreq/mediatek-cpufreq-hw.c | 42 ++++++++++++++++++++++-------------
 1 file changed, 27 insertions(+), 15 deletions(-)

diff --git a/drivers/cpufreq/mediatek-cpufreq-hw.c b/drivers/cpufreq/mediatek-cpufreq-hw.c
index b2aba1842226c7d24a8b9599ea62408cac9f803c..53611077d0d9a2d9865cf771568ab71abc0e6fbd 100644
--- a/drivers/cpufreq/mediatek-cpufreq-hw.c
+++ b/drivers/cpufreq/mediatek-cpufreq-hw.c
@@ -35,13 +35,17 @@ enum {
 	REG_ARRAY_SIZE,
 };
 
-struct mtk_cpufreq_data {
+struct mtk_cpufreq_priv {
+	const struct mtk_cpufreq_variant *variant;
+};
+
+struct mtk_cpufreq_domain {
+	struct mtk_cpufreq_priv *parent;
 	struct cpufreq_frequency_table *table;
 	void __iomem *reg_bases[REG_ARRAY_SIZE];
 	struct resource *res;
 	void __iomem *base;
 	int nr_opp;
-	const struct mtk_cpufreq_variant *variant;
 };
 
 struct mtk_cpufreq_variant {
@@ -63,7 +67,7 @@ static int __maybe_unused
 mtk_cpufreq_get_cpu_power(struct device *cpu_dev, unsigned long *uW,
 			  unsigned long *KHz)
 {
-	struct mtk_cpufreq_data *data;
+	struct mtk_cpufreq_domain *data;
 	struct cpufreq_policy *policy;
 	int i;
 
@@ -90,7 +94,7 @@ mtk_cpufreq_get_cpu_power(struct device *cpu_dev, unsigned long *uW,
 static int mtk_cpufreq_hw_target_index(struct cpufreq_policy *policy,
 				       unsigned int index)
 {
-	struct mtk_cpufreq_data *data = policy->driver_data;
+	struct mtk_cpufreq_domain *data = policy->driver_data;
 
 	writel_relaxed(index, data->reg_bases[REG_FREQ_PERF_STATE]);
 
@@ -99,7 +103,7 @@ static int mtk_cpufreq_hw_target_index(struct cpufreq_policy *policy,
 
 static unsigned int mtk_cpufreq_hw_get(unsigned int cpu)
 {
-	struct mtk_cpufreq_data *data;
+	struct mtk_cpufreq_domain *data;
 	struct cpufreq_policy *policy;
 	unsigned int index;
 
@@ -118,7 +122,7 @@ static unsigned int mtk_cpufreq_hw_get(unsigned int cpu)
 static unsigned int mtk_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
 					       unsigned int target_freq)
 {
-	struct mtk_cpufreq_data *data = policy->driver_data;
+	struct mtk_cpufreq_domain *data = policy->driver_data;
 	unsigned int index;
 
 	index = cpufreq_table_find_index_dl(policy, target_freq, false);
@@ -129,7 +133,7 @@ static unsigned int mtk_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
 }
 
 static int mtk_cpu_create_freq_table(struct platform_device *pdev,
-				     struct mtk_cpufreq_data *data)
+				     struct mtk_cpufreq_domain *data)
 {
 	struct device *dev = &pdev->dev;
 	u32 temp, i, freq, prev_freq = 0;
@@ -164,9 +168,9 @@ static int mtk_cpu_create_freq_table(struct platform_device *pdev,
 
 static int mtk_cpu_resources_init(struct platform_device *pdev,
 				  struct cpufreq_policy *policy,
-				  const struct mtk_cpufreq_variant *variant)
+				  struct mtk_cpufreq_priv *priv)
 {
-	struct mtk_cpufreq_data *data;
+	struct mtk_cpufreq_domain *data;
 	struct device *dev = &pdev->dev;
 	struct resource *res;
 	struct of_phandle_args args;
@@ -187,6 +191,8 @@ static int mtk_cpu_resources_init(struct platform_device *pdev,
 	index = args.args[0];
 	of_node_put(args.np);
 
+	data->parent = priv;
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
 	if (!res) {
 		dev_err(dev, "failed to get mem resource %d\n", index);
@@ -207,10 +213,9 @@ static int mtk_cpu_resources_init(struct platform_device *pdev,
 
 	data->base = base;
 	data->res = res;
-	data->variant = variant;
 
 	for (i = REG_FREQ_LUT_TABLE; i < REG_ARRAY_SIZE; i++)
-		data->reg_bases[i] = base + variant->reg_offsets[i];
+		data->reg_bases[i] = base + priv->variant->reg_offsets[i];
 
 	ret = mtk_cpu_create_freq_table(pdev, data);
 	if (ret) {
@@ -231,7 +236,7 @@ static int mtk_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
 {
 	struct platform_device *pdev = cpufreq_get_driver_data();
 	int sig, pwr_hw = CPUFREQ_HW_STATUS | SVS_HW_STATUS;
-	struct mtk_cpufreq_data *data;
+	struct mtk_cpufreq_domain *data;
 	unsigned int latency;
 	int ret;
 
@@ -270,7 +275,7 @@ static int mtk_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
 
 static void mtk_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
 {
-	struct mtk_cpufreq_data *data = policy->driver_data;
+	struct mtk_cpufreq_domain *data = policy->driver_data;
 	struct resource *res = data->res;
 	void __iomem *base = data->base;
 
@@ -283,7 +288,7 @@ static void mtk_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
 static void mtk_cpufreq_register_em(struct cpufreq_policy *policy)
 {
 	struct em_data_callback em_cb = EM_DATA_CB(mtk_cpufreq_get_cpu_power);
-	struct mtk_cpufreq_data *data = policy->driver_data;
+	struct mtk_cpufreq_domain *data = policy->driver_data;
 
 	em_dev_register_perf_domain(get_cpu_device(policy->cpu), data->nr_opp,
 				    &em_cb, policy->cpus, true);
@@ -305,6 +310,7 @@ static struct cpufreq_driver cpufreq_mtk_hw_driver = {
 
 static int mtk_cpufreq_hw_driver_probe(struct platform_device *pdev)
 {
+	struct mtk_cpufreq_priv *priv;
 	const void *data;
 	int ret, cpu;
 	struct device *cpu_dev;
@@ -328,7 +334,13 @@ static int mtk_cpufreq_hw_driver_probe(struct platform_device *pdev)
 	if (!data)
 		return -EINVAL;
 
-	platform_set_drvdata(pdev, (void *) data);
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->variant = data;
+
+	platform_set_drvdata(pdev, priv);
 	cpufreq_mtk_hw_driver.driver_data = pdev;
 
 	ret = cpufreq_register_driver(&cpufreq_mtk_hw_driver);

-- 
2.50.1

[PATCH v3 4/4] cpufreq: mediatek-hw: Add support for MT8196

[Nicolas Frattaroli]

The MT8196 SoC uses DVFS to set a desired target frequency for each CPU
core. It also uses slightly different register offsets.

Add support for it, which necessitates reworking how the mmio regs are
acquired, as mt8196 has the fdvfs register before the performance domain
registers.

I've verified with both `sysbench cpu run` and `head -c 10G \
/dev/urandom | pigz -p 8 -c - | pv -ba > /dev/null` that we don't just
get a higher reported clock frequency, but that the observed performance
also increases, by a factor of 2.64 in an 8 thread sysbench test.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
---
 drivers/cpufreq/mediatek-cpufreq-hw.c | 70 ++++++++++++++++++++++++++++++++++-
 1 file changed, 68 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/mediatek-cpufreq-hw.c b/drivers/cpufreq/mediatek-cpufreq-hw.c
index 53611077d0d9a2d9865cf771568ab71abc0e6fbd..e4eadce6f937ceff51b34d22da83c51b4e9aa813 100644
--- a/drivers/cpufreq/mediatek-cpufreq-hw.c
+++ b/drivers/cpufreq/mediatek-cpufreq-hw.c
@@ -24,6 +24,8 @@
 #define POLL_USEC			1000
 #define TIMEOUT_USEC			300000
 
+#define FDVFS_FDIV_HZ (26 * 1000)
+
 enum {
 	REG_FREQ_LUT_TABLE,
 	REG_FREQ_ENABLE,
@@ -36,7 +38,9 @@ enum {
 };
 
 struct mtk_cpufreq_priv {
+	struct device *dev;
 	const struct mtk_cpufreq_variant *variant;
+	void __iomem *fdvfs;
 };
 
 struct mtk_cpufreq_domain {
@@ -49,7 +53,9 @@ struct mtk_cpufreq_domain {
 };
 
 struct mtk_cpufreq_variant {
+	int (*init)(struct mtk_cpufreq_priv *priv);
 	const u16 reg_offsets[REG_ARRAY_SIZE];
+	const bool is_hybrid_dvfs;
 };
 
 static const struct mtk_cpufreq_variant cpufreq_mtk_base_variant = {
@@ -63,6 +69,29 @@ static const struct mtk_cpufreq_variant cpufreq_mtk_base_variant = {
 	},
 };
 
+static int mtk_cpufreq_hw_mt8196_init(struct mtk_cpufreq_priv *priv)
+{
+	priv->fdvfs = devm_of_iomap(priv->dev, priv->dev->of_node, 0, NULL);
+	if (IS_ERR_OR_NULL(priv->fdvfs))
+		return dev_err_probe(priv->dev, PTR_ERR(priv->fdvfs),
+				     "failed to get fdvfs iomem\n");
+
+	return 0;
+}
+
+static const struct mtk_cpufreq_variant cpufreq_mtk_mt8196_variant = {
+	.init = mtk_cpufreq_hw_mt8196_init,
+	.reg_offsets = {
+		[REG_FREQ_LUT_TABLE]	= 0x0,
+		[REG_FREQ_ENABLE]	= 0x84,
+		[REG_FREQ_PERF_STATE]	= 0x88,
+		[REG_FREQ_HW_STATE]	= 0x8c,
+		[REG_EM_POWER_TBL]	= 0x90,
+		[REG_FREQ_LATENCY]	= 0x114,
+	},
+	.is_hybrid_dvfs = true,
+};
+
 static int __maybe_unused
 mtk_cpufreq_get_cpu_power(struct device *cpu_dev, unsigned long *uW,
 			  unsigned long *KHz)
@@ -91,12 +120,31 @@ mtk_cpufreq_get_cpu_power(struct device *cpu_dev, unsigned long *uW,
 	return 0;
 }
 
+static void mtk_cpufreq_hw_fdvfs_switch(unsigned int target_freq,
+					struct cpufreq_policy *policy)
+{
+	struct mtk_cpufreq_domain *data = policy->driver_data;
+	struct mtk_cpufreq_priv *priv = data->parent;
+	unsigned int cpu;
+
+	target_freq = DIV_ROUND_UP(target_freq, FDVFS_FDIV_HZ);
+	for_each_cpu(cpu, policy->real_cpus) {
+		writel_relaxed(target_freq, priv->fdvfs + cpu * 4);
+	}
+}
+
 static int mtk_cpufreq_hw_target_index(struct cpufreq_policy *policy,
 				       unsigned int index)
 {
 	struct mtk_cpufreq_domain *data = policy->driver_data;
+	unsigned int target_freq;
 
-	writel_relaxed(index, data->reg_bases[REG_FREQ_PERF_STATE]);
+	if (data->parent->fdvfs) {
+		target_freq = policy->freq_table[index].frequency;
+		mtk_cpufreq_hw_fdvfs_switch(target_freq, policy);
+	} else {
+		writel_relaxed(index, data->reg_bases[REG_FREQ_PERF_STATE]);
+	}
 
 	return 0;
 }
@@ -127,7 +175,10 @@ static unsigned int mtk_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
 
 	index = cpufreq_table_find_index_dl(policy, target_freq, false);
 
-	writel_relaxed(index, data->reg_bases[REG_FREQ_PERF_STATE]);
+	if (data->parent->fdvfs)
+		mtk_cpufreq_hw_fdvfs_switch(target_freq, policy);
+	else
+		writel_relaxed(index, data->reg_bases[REG_FREQ_PERF_STATE]);
 
 	return policy->freq_table[index].frequency;
 }
@@ -191,6 +242,13 @@ static int mtk_cpu_resources_init(struct platform_device *pdev,
 	index = args.args[0];
 	of_node_put(args.np);
 
+	/*
+	 * In a cpufreq with hybrid DVFS, such as the MT8196, the first declared
+	 * register range is for FDVFS, followed by the frequency domain MMIOs.
+	 */
+	if (priv->variant->is_hybrid_dvfs)
+		index++;
+
 	data->parent = priv;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
@@ -339,6 +397,13 @@ static int mtk_cpufreq_hw_driver_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	priv->variant = data;
+	priv->dev = &pdev->dev;
+
+	if (priv->variant->init) {
+		ret = priv->variant->init(priv);
+		if (ret)
+			return ret;
+	}
 
 	platform_set_drvdata(pdev, priv);
 	cpufreq_mtk_hw_driver.driver_data = pdev;
@@ -357,6 +422,7 @@ static void mtk_cpufreq_hw_driver_remove(struct platform_device *pdev)
 
 static const struct of_device_id mtk_cpufreq_hw_match[] = {
 	{ .compatible = "mediatek,cpufreq-hw", .data = &cpufreq_mtk_base_variant },
+	{ .compatible = "mediatek,mt8196-cpufreq-hw", .data = &cpufreq_mtk_mt8196_variant },
 	{}
 };
 MODULE_DEVICE_TABLE(of, mtk_cpufreq_hw_match);

-- 
2.50.1

Re: [PATCH v3 4/4] cpufreq: mediatek-hw: Add support for MT8196

[AngeloGioacchino Del Regno]

Il 16/07/25 19:51, Nicolas Frattaroli ha scritto:
> The MT8196 SoC uses DVFS to set a desired target frequency for each CPU
> core. It also uses slightly different register offsets.
> 
> Add support for it, which necessitates reworking how the mmio regs are
> acquired, as mt8196 has the fdvfs register before the performance domain
> registers.
> 
> I've verified with both `sysbench cpu run` and `head -c 10G \
> /dev/urandom | pigz -p 8 -c - | pv -ba > /dev/null` that we don't just
> get a higher reported clock frequency, but that the observed performance
> also increases, by a factor of 2.64 in an 8 thread sysbench test.
> 
> Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>

Reviewed-by: AngeloGioacchino Del Regno <angelogiaocchino.delregno@collabora.com>

Re: [PATCH v3 0/4] MT8196 CPUFreq Support

[Viresh Kumar]

On 16-07-25, 19:51, Nicolas Frattaroli wrote:
> This series adds the necessary bindings and driver changes to integrate
> MT8196 CPUFreq into the existing mediatek-cpufreq-hw driver. This
> necessitated two preparatory cleanup patches to the driver.
> 
> The CPU frequency was verified to actually be changing by comparing
> sysbench cpu numbers between fdvfs being enabled and it not being
> enabled.
> 
> Enablement in the DT will be done once the MT8196 DT lands, so don't be
> surprised that no node uses these new compatibles so far.
> 
> Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
> ---
> Changes in v3:
> - bindings: changed title as per angelo's suggestions
> - bindings: dropped the fdvfs magic register range
> - bindings: dropped redundant description for #performance-domain-cells
> - driver: made fdvfs frequency divisor a `#define` instead of part of
>   the variant struct
> - driver: dropped fdvfs magic check
> - driver: reworked performance domain resource offset
> - Link to v2: https://lore.kernel.org/r/20250714-mt8196-cpufreq-v2-0-cc85e78855c7@collabora.com

Applied. Thanks.

-- 
viresh