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[PATCH v5 6/6] clk: scmi: Add i.MX95 OEM extension support for SCMI clock driver

Peng Fan posted 6 patches 2 months, 1 week ago
There is a newer version of this series
[PATCH v5 6/6] clk: scmi: Add i.MX95 OEM extension support for SCMI clock driver
Posted by Peng Fan 2 months, 1 week ago 
 - Introduce 'clk-scmi-oem.c' to support vendor-specific OEM extensions
   for the SCMI clock driver, allows clean integration of vendor-specific
   features without impacting the core SCMI clock driver logic.
 - Extend 'clk-scmi.h' with 'scmi_clk_oem' structure and related declarations.
 - Initialize OEM extensions via 'scmi_clk_oem_init()'.
 - Support querying OEM-specific features and setting spread spectrum.
 - Pass 'scmi_device' to 'scmi_clk_ops_select()' for OEM data access.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/clk/Makefile       |   2 +-
 drivers/clk/clk-scmi-oem.c | 103 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/clk/clk-scmi.c     |  19 +++++++--
 drivers/clk/clk-scmi.h     |  11 +++++
 4 files changed, 131 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 9e8c989b24be0f7cfdf2325c9b19d05e9d2a8eb9..fd54e2fe3c429362b93457d0e349e1deab2320f3 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -95,7 +95,7 @@ obj-$(CONFIG_COMMON_CLK_RP1)            += clk-rp1.o
 obj-$(CONFIG_COMMON_CLK_RPMI)		+= clk-rpmi.o
 obj-$(CONFIG_COMMON_CLK_HI655X)		+= clk-hi655x.o
 obj-$(CONFIG_COMMON_CLK_S2MPS11)	+= clk-s2mps11.o
-obj-$(CONFIG_COMMON_CLK_SCMI)           += clk-scmi.o
+obj-$(CONFIG_COMMON_CLK_SCMI)           += clk-scmi.o clk-scmi-oem.o
 obj-$(CONFIG_COMMON_CLK_SCPI)           += clk-scpi.o
 obj-$(CONFIG_COMMON_CLK_SI5341)		+= clk-si5341.o
 obj-$(CONFIG_COMMON_CLK_SI5351)		+= clk-si5351.o
diff --git a/drivers/clk/clk-scmi-oem.c b/drivers/clk/clk-scmi-oem.c
new file mode 100644
index 0000000000000000000000000000000000000000..0d7f4e423168f759ecf4fcc9e51324420e19f97c
--- /dev/null
+++ b/drivers/clk/clk-scmi-oem.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * The Vendor OEM extension for System Control and Power Interface (SCMI)
+ * Protocol based clock driver
+ *
+ * Copyright 2025 NXP
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/of.h>
+#include <linux/scmi_imx_protocol.h>
+#include <linux/scmi_protocol.h>
+
+#include "clk-scmi.h"
+
+#define SCMI_CLOCK_CFG_IMX_SSC			0x80
+#define SCMI_CLOCK_IMX_SS_PERCENTAGE_MASK	GENMASK(7, 0)
+#define SCMI_CLOCK_IMX_SS_MOD_FREQ_MASK		GENMASK(23, 8)
+#define SCMI_CLOCK_IMX_SS_ENABLE_MASK		BIT(24)
+
+struct scmi_clk_oem_info {
+	char *vendor_id;
+	char *sub_vendor_id;
+	char *compatible;
+	const void *data;
+};
+
+static int
+scmi_clk_imx_set_spread_spectrum(struct clk_hw *hw,
+				 const struct clk_spread_spectrum *ss_conf)
+{
+	struct scmi_clk *clk = to_scmi_clk(hw);
+	int ret;
+	u32 val;
+
+	/*
+	 * extConfigValue[7:0]   - spread percentage (%)
+	 * extConfigValue[23:8]  - Modulation Frequency
+	 * extConfigValue[24]    - Enable/Disable
+	 * extConfigValue[31:25] - Reserved
+	 */
+	val = FIELD_PREP(SCMI_CLOCK_IMX_SS_PERCENTAGE_MASK, ss_conf->spread_bp / 10000);
+	val |= FIELD_PREP(SCMI_CLOCK_IMX_SS_MOD_FREQ_MASK, ss_conf->modfreq_hz);
+	if (ss_conf->method != CLK_SPREAD_NO)
+		val |= SCMI_CLOCK_IMX_SS_ENABLE_MASK;
+	ret = scmi_proto_clk_ops->config_oem_set(clk->ph, clk->id,
+						 SCMI_CLOCK_CFG_IMX_SSC,
+						 val, false);
+	if (ret)
+		dev_warn(clk->dev,
+			 "Failed to set spread spectrum(%u,%u,%u) for clock ID %d\n",
+			 ss_conf->modfreq_hz, ss_conf->spread_bp, ss_conf->method,
+			 clk->id);
+
+	return ret;
+}
+
+static int
+scmi_clk_imx_query_oem_feats(const struct scmi_protocol_handle *ph, u32 id,
+			     unsigned int *feats_key)
+{
+	int ret;
+	u32 val;
+
+	ret = scmi_proto_clk_ops->config_oem_get(ph, id,
+						 SCMI_CLOCK_CFG_IMX_SSC,
+						 &val, NULL, false);
+	if (!ret)
+		*feats_key |= BIT(SCMI_CLK_EXT_OEM_SSC_SUPPORTED);
+
+	return 0;
+}
+
+static const struct scmi_clk_oem scmi_clk_oem_imx = {
+	.query_ext_oem_feats = scmi_clk_imx_query_oem_feats,
+	.set_spread_spectrum = scmi_clk_imx_set_spread_spectrum,
+};
+
+const struct scmi_clk_oem_info info[] = {
+	{ SCMI_IMX_VENDOR, SCMI_IMX_SUBVENDOR, NULL, &scmi_clk_oem_imx },
+};
+
+int scmi_clk_oem_init(struct scmi_device *sdev)
+{
+	const struct scmi_handle *handle = sdev->handle;
+	int i, size = ARRAY_SIZE(info);
+
+	for (i = 0; i < size; i++) {
+		if (strcmp(handle->version->vendor_id, SCMI_IMX_VENDOR) ||
+		    strcmp(handle->version->sub_vendor_id, SCMI_IMX_SUBVENDOR))
+			continue;
+		if (info[i].compatible &&
+		    !of_machine_is_compatible(info[i].compatible))
+			continue;
+
+		break;
+	}
+
+	if (i < size)
+		dev_set_drvdata(&sdev->dev, (void *)info[i].data);
+
+	return 0;
+}
diff --git a/drivers/clk/clk-scmi.c b/drivers/clk/clk-scmi.c
index bf85924d61985eb9e596419349eb883e3817de73..1ed2091e3d4a951c8662db4c94dee4b9c98b8326 100644
--- a/drivers/clk/clk-scmi.c
+++ b/drivers/clk/clk-scmi.c
@@ -14,6 +14,8 @@
 #include <linux/scmi_protocol.h>
 #include <asm/div64.h>
 
+#include "clk-scmi.h"
+
 const struct scmi_clk_proto_ops *scmi_proto_clk_ops;
 
 static unsigned long scmi_clk_recalc_rate(struct clk_hw *hw,
@@ -242,6 +244,7 @@ static int scmi_clk_ops_init(struct device *dev, struct scmi_clk *sclk,
 static const struct clk_ops *
 scmi_clk_ops_alloc(struct device *dev, unsigned long feats_key)
 {
+	struct scmi_clk_oem *oem_data = dev_get_drvdata(dev);
 	struct clk_ops *ops;
 
 	ops = devm_kzalloc(dev, sizeof(*ops), GFP_KERNEL);
@@ -288,11 +291,15 @@ scmi_clk_ops_alloc(struct device *dev, unsigned long feats_key)
 		ops->set_duty_cycle = scmi_clk_set_duty_cycle;
 	}
 
+	if (oem_data && (feats_key & BIT(SCMI_CLK_EXT_OEM_SSC_SUPPORTED)))
+		ops->set_spread_spectrum = oem_data->set_spread_spectrum;
+
 	return ops;
 }
 
 /**
  * scmi_clk_ops_select() - Select a proper set of clock operations
+ * @sdev: pointer to the SCMI device
  * @sclk: A reference to an SCMI clock descriptor
  * @atomic_capable: A flag to indicate if atomic mode is supported by the
  *		    transport
@@ -317,8 +324,8 @@ scmi_clk_ops_alloc(struct device *dev, unsigned long feats_key)
  *	   NULL otherwise.
  */
 static const struct clk_ops *
-scmi_clk_ops_select(struct scmi_clk *sclk, bool atomic_capable,
-		    unsigned int atomic_threshold_us,
+scmi_clk_ops_select(struct scmi_device *sdev, struct scmi_clk *sclk,
+		    bool atomic_capable, unsigned int atomic_threshold_us,
 		    const struct clk_ops **clk_ops_db, size_t db_size)
 {
 	int ret;
@@ -326,6 +333,7 @@ scmi_clk_ops_select(struct scmi_clk *sclk, bool atomic_capable,
 	const struct scmi_clock_info *ci = sclk->info;
 	unsigned int feats_key = 0;
 	const struct clk_ops *ops;
+	struct scmi_clk_oem *oem_data = dev_get_drvdata(&sdev->dev);
 
 	/*
 	 * Note that when transport is atomic but SCMI protocol did not
@@ -350,6 +358,9 @@ scmi_clk_ops_select(struct scmi_clk *sclk, bool atomic_capable,
 						 &val, NULL, false);
 		if (!ret)
 			feats_key |= BIT(SCMI_CLK_DUTY_CYCLE_SUPPORTED);
+
+		if (oem_data && oem_data->query_ext_oem_feats)
+			oem_data->query_ext_oem_feats(sclk->ph, sclk->id, &feats_key);
 	}
 
 	if (WARN_ON(feats_key >= db_size))
@@ -407,6 +418,8 @@ static int scmi_clocks_probe(struct scmi_device *sdev)
 	clk_data->num = count;
 	hws = clk_data->hws;
 
+	scmi_clk_oem_init(sdev);
+
 	transport_is_atomic = handle->is_transport_atomic(handle,
 							  &atomic_threshold_us);
 
@@ -438,7 +451,7 @@ static int scmi_clocks_probe(struct scmi_device *sdev)
 		 * to avoid sharing the devm_ allocated clk_ops between multiple
 		 * SCMI clk driver instances.
 		 */
-		scmi_ops = scmi_clk_ops_select(sclk, transport_is_atomic,
+		scmi_ops = scmi_clk_ops_select(sdev, sclk, transport_is_atomic,
 					       atomic_threshold_us,
 					       scmi_clk_ops_db,
 					       ARRAY_SIZE(scmi_clk_ops_db));
diff --git a/drivers/clk/clk-scmi.h b/drivers/clk/clk-scmi.h
index 6ef6adc77c836dc2d599ff852cdc941f217ee388..d7f63f36c56d155f728325efd6bcf7fe2585b170 100644
--- a/drivers/clk/clk-scmi.h
+++ b/drivers/clk/clk-scmi.h
@@ -7,6 +7,7 @@
 #define __SCMI_CLK_H
 
 #include <linux/bits.h>
+#include <linux/clk-provider.h>
 #include <linux/scmi_protocol.h>
 #include <linux/types.h>
 
@@ -19,6 +20,7 @@ enum scmi_clk_feats {
 	SCMI_CLK_RATE_CTRL_SUPPORTED,
 	SCMI_CLK_PARENT_CTRL_SUPPORTED,
 	SCMI_CLK_DUTY_CYCLE_SUPPORTED,
+	SCMI_CLK_EXT_OEM_SSC_SUPPORTED,
 	SCMI_CLK_FEATS_COUNT
 };
 
@@ -37,4 +39,13 @@ struct scmi_clk {
 
 extern const struct scmi_clk_proto_ops *scmi_proto_clk_ops;
 
+struct scmi_clk_oem {
+	int (*query_ext_oem_feats)(const struct scmi_protocol_handle *ph,
+				   u32 id, unsigned int *feats_key);
+	int (*set_spread_spectrum)(struct clk_hw *hw,
+				   const struct clk_spread_spectrum *ss_conf);
+};
+
+int scmi_clk_oem_init(struct scmi_device *dev);
+
 #endif

-- 
2.37.1
Re: [PATCH v5 6/6] clk: scmi: Add i.MX95 OEM extension support for SCMI clock driver
Posted by Sebin Francis 1 month, 2 weeks ago 
Hi Peng,

On 09/10/25 09:18, Peng Fan wrote:
>   - Introduce 'clk-scmi-oem.c' to support vendor-specific OEM extensions
>     for the SCMI clock driver, allows clean integration of vendor-specific
>     features without impacting the core SCMI clock driver logic.
>   - Extend 'clk-scmi.h' with 'scmi_clk_oem' structure and related declarations.
>   - Initialize OEM extensions via 'scmi_clk_oem_init()'.
>   - Support querying OEM-specific features and setting spread spectrum.
>   - Pass 'scmi_device' to 'scmi_clk_ops_select()' for OEM data access.
> 
> Signed-off-by: Peng Fan <peng.fan@nxp.com>

Thanks for the patch. I only have a minor comment, otherwise the patch 
looks good.

[...]

> +
> +int scmi_clk_oem_init(struct scmi_device *sdev)
> +{
> +	const struct scmi_handle *handle = sdev->handle;
> +	int i, size = ARRAY_SIZE(info);
> +
> +	for (i = 0; i < size; i++) {
> +		if (strcmp(handle->version->vendor_id, SCMI_IMX_VENDOR) ||
> +		    strcmp(handle->version->sub_vendor_id, SCMI_IMX_SUBVENDOR))
> +			continue;
> +		if (info[i].compatible &&
> +		    !of_machine_is_compatible(info[i].compatible))
> +			continue;
> +
> +		break;
> +	}
> +
> +	if (i < size)
> +		dev_set_drvdata(&sdev->dev, (void *)info[i].data);
> +
> +	return 0;
> +}

This above logic is tailor made for IMX is it possible to make it generic?

> diff --git a/drivers/clk/clk-scmi.c b/drivers/clk/clk-scmi.c
> index bf85924d61985eb9e596419349eb883e3817de73..1ed2091e3d4a951c8662db4c94dee4b9c98b8326 100644
> --- a/drivers/clk/clk-scmi.c
> +++ b/drivers/clk/clk-scmi.c
> @@ -14,6 +14,8 @@
>   #include <linux/scmi_protocol.h>
>   #include <asm/div64.h>
>   
> +#include "clk-scmi.h"

[...]


Thanks
Sebin
Re: [PATCH v5 6/6] clk: scmi: Add i.MX95 OEM extension support for SCMI clock driver
Posted by Geert Uytterhoeven 1 month, 3 weeks ago 
Hi Peng,

On Thu, 9 Oct 2025 at 05:49, Peng Fan <peng.fan@nxp.com> wrote:
>  - Introduce 'clk-scmi-oem.c' to support vendor-specific OEM extensions
>    for the SCMI clock driver, allows clean integration of vendor-specific
>    features without impacting the core SCMI clock driver logic.
>  - Extend 'clk-scmi.h' with 'scmi_clk_oem' structure and related declarations.
>  - Initialize OEM extensions via 'scmi_clk_oem_init()'.
>  - Support querying OEM-specific features and setting spread spectrum.
>  - Pass 'scmi_device' to 'scmi_clk_ops_select()' for OEM data access.
>
> Signed-off-by: Peng Fan <peng.fan@nxp.com>

Thanks for your patch!

> --- /dev/null
> +++ b/drivers/clk/clk-scmi-oem.c
> @@ -0,0 +1,103 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * The Vendor OEM extension for System Control and Power Interface (SCMI)
> + * Protocol based clock driver
> + *
> + * Copyright 2025 NXP
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/of.h>
> +#include <linux/scmi_imx_protocol.h>
> +#include <linux/scmi_protocol.h>
> +
> +#include "clk-scmi.h"
> +
> +#define SCMI_CLOCK_CFG_IMX_SSC                 0x80
> +#define SCMI_CLOCK_IMX_SS_PERCENTAGE_MASK      GENMASK(7, 0)
> +#define SCMI_CLOCK_IMX_SS_MOD_FREQ_MASK                GENMASK(23, 8)
> +#define SCMI_CLOCK_IMX_SS_ENABLE_MASK          BIT(24)
> +
> +struct scmi_clk_oem_info {
> +       char *vendor_id;
> +       char *sub_vendor_id;
> +       char *compatible;
> +       const void *data;
> +};
> +
> +static int
> +scmi_clk_imx_set_spread_spectrum(struct clk_hw *hw,
> +                                const struct clk_spread_spectrum *ss_conf)
> +{
> +       struct scmi_clk *clk = to_scmi_clk(hw);
> +       int ret;
> +       u32 val;
> +
> +       /*
> +        * extConfigValue[7:0]   - spread percentage (%)
> +        * extConfigValue[23:8]  - Modulation Frequency

What is the unit of this?
According to the code below, it is in Hz, so it is limited to 65535 Hz.

> +        * extConfigValue[24]    - Enable/Disable
> +        * extConfigValue[31:25] - Reserved

Center, up, down, could be stored here, I assume?

> +        */
> +       val = FIELD_PREP(SCMI_CLOCK_IMX_SS_PERCENTAGE_MASK, ss_conf->spread_bp / 10000);
> +       val |= FIELD_PREP(SCMI_CLOCK_IMX_SS_MOD_FREQ_MASK, ss_conf->modfreq_hz);
> +       if (ss_conf->method != CLK_SPREAD_NO)
> +               val |= SCMI_CLOCK_IMX_SS_ENABLE_MASK;
> +       ret = scmi_proto_clk_ops->config_oem_set(clk->ph, clk->id,
> +                                                SCMI_CLOCK_CFG_IMX_SSC,
> +                                                val, false);
> +       if (ret)
> +               dev_warn(clk->dev,
> +                        "Failed to set spread spectrum(%u,%u,%u) for clock ID %d\n",
> +                        ss_conf->modfreq_hz, ss_conf->spread_bp, ss_conf->method,
> +                        clk->id);
> +
> +       return ret;
> +}

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
Re: [PATCH v5 6/6] clk: scmi: Add i.MX95 OEM extension support for SCMI clock driver
Posted by Peng Fan 1 month, 3 weeks ago 
Hi All,

On Thu, Oct 09, 2025 at 11:48:19AM +0800, Peng Fan wrote:
> - Introduce 'clk-scmi-oem.c' to support vendor-specific OEM extensions
>   for the SCMI clock driver, allows clean integration of vendor-specific
>   features without impacting the core SCMI clock driver logic.
> - Extend 'clk-scmi.h' with 'scmi_clk_oem' structure and related declarations.
> - Initialize OEM extensions via 'scmi_clk_oem_init()'.
> - Support querying OEM-specific features and setting spread spectrum.
> - Pass 'scmi_device' to 'scmi_clk_ops_select()' for OEM data access.

Just would like to request your feedback regarding the SCMI clock driver OEM
extension. I'd appreciate any feedback or suggestions you might have.

Thanks,
Peng

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