[PATCH v7 6/6] clk: scmi: Add i.MX95 OEM extension support for SCMI clock driver
Cristian Marussi
cristian.marussi at arm.com
Sat Feb 28 02:02:04 PST 2026
On Wed, Dec 31, 2025 at 06:12:53PM +0800, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan at nxp.com>
>
> - 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.
Hi,
>
> Reviewed-by: Sebin Francis <sebin.francis at ti.com>
> Signed-off-by: Peng Fan <peng.fan at 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 cb10156db2a37e1956d84113d1711e23d9d864ab..8e0e03a79f793ffab6c8636b7796c067287e1712 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..fd81aca7bfca254669ee117ebd51e481a74cdcb4
> --- /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;
I suppose different OEM per impl_ver is overkill...and maybe better
to be trated as a bug if it happens leveraging the Quirk framework..
> + 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[] = {
Any reason why this cannot be made static too ?
Given that you just embed it with set_drvdata and then get_drvdata
back from the main clk driver...
> + { 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, info[i].vendor_id) ||
> + strcmp(handle->version->sub_vendor_id, info[i].sub_vendor_id))
> + 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
>
Other than the above, LGTM.
Reviewed-by: Cristian Marussi <cristian.marussi at arm.com>
Thanks,
Cristian
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