firmware: import Linux v5.13 SCMI support

The ARM System Control and Management Interface (SCMI) is a standard way
to offload handling of system resources like clocks, resets and power
domain handling to the firmware. This should replace Silicon Provider
specific conduits for new SoCs. Systems where this is already relevant:

  - STM32MP1: For trusted boot, the clock and reset controller are
    managed from secure world. This is not yet supported by barebox and
    must be disabled in TF-A
  - RK3568: At least the CPU clock is only controllable via SCMI
  - i.MX8X: Communication with the SCU occurs via SCMI

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20220220124736.3052502-13-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

5 files changed, 768 insertions, 0 deletions

diff --git a/include/driver.h b/include/driver.h
index a787f985a0..e59f0a164d 100644
--- a/include/driver.h
+++ b/include/driver.h
@@ -595,4 +595,7 @@ const void *device_get_match_data(struct device_d *dev);
 
 int device_match_of_modalias(struct device_d *dev, struct driver_d *drv);
 
+struct device_d *device_find_child(struct device_d *parent, void *data,
+				 int (*match)(struct device_d *dev, void *data));
+
 #endif /* DRIVER_H */
diff --git a/include/linux/idr.h b/include/linux/idr.h
new file mode 100644
index 0000000000..8a0f452d76
--- /dev/null
+++ b/include/linux/idr.h
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * include/linux/idr.h
+ * 
+ * 2002-10-18  written by Jim Houston jim.houston@ccur.com
+ *	Copyright (C) 2002 by Concurrent Computer Corporation
+ *
+ * Small id to pointer translation service avoiding fixed sized
+ * tables.
+ */
+
+#ifndef __IDR_H__
+#define __IDR_H__
+
+#include <errno.h>
+#include <linux/list.h>
+
+struct idr {
+	int			id;
+	void			*ptr;
+	struct list_head	list;
+};
+
+#define DEFINE_IDR(name)	\
+	struct idr name = { .list = LIST_HEAD_INIT((name).list) }
+
+#define __idr_for_each_entry(head, idr) \
+	list_for_each_entry((idr), &(head)->list, list)
+
+static inline struct idr *__idr_find(struct idr *head, int id)
+{
+	struct idr *idr;
+
+	__idr_for_each_entry(head, idr) {
+		if (idr->id == id)
+			return idr;
+	}
+
+	return NULL;
+}
+
+static inline void *idr_find(struct idr *head, int id)
+{
+	struct idr *idr = __idr_find(head, id);
+
+	return idr ? idr->ptr : NULL;
+}
+
+static inline int idr_alloc_one(struct idr *head, void *ptr, int start)
+{
+	struct idr *idr;
+
+	if (__idr_find(head, start))
+		return -EBUSY;
+
+	idr = malloc(sizeof(*idr));
+
+	idr->id = start;
+	idr->ptr = ptr;
+
+	list_add(&idr->list, &head->list);
+
+	return start;
+}
+
+static inline void idr_init(struct idr *idr)
+{
+	INIT_LIST_HEAD(&idr->list);
+}
+
+static inline void idr_remove(struct idr *head, int id)
+{
+	struct idr *idr = __idr_find(head, id);
+
+	list_del(&idr->list);
+	free(idr);
+}
+
+#endif /* __IDR_H__ */
diff --git a/include/linux/processor.h b/include/linux/processor.h
new file mode 100644
index 0000000000..94a458c3d1
--- /dev/null
+++ b/include/linux/processor.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Misc low level processor primitives */
+#ifndef _LINUX_PROCESSOR_H
+#define _LINUX_PROCESSOR_H
+
+#include <linux/barebox-wrapper.h>
+
+/*
+ * spin_until_cond can be used to wait for a condition to become true. It
+ * may be expected that the first iteration will true in the common case
+ * (no spinning), so that callers should not require a first "likely" test
+ * for the uncontended case before using this primitive.
+ *
+ * Usage and implementation guidelines are the same as for the spin_begin
+ * primitives, above.
+ */
+#ifndef spin_until_cond
+#define spin_until_cond(cond)					\
+do {								\
+	if (unlikely(!(cond))) {				\
+		do {						\
+			cpu_relax();				\
+		} while (!(cond));				\
+	}							\
+} while (0)
+
+#endif
+
+#endif /* _LINUX_PROCESSOR_H */
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
new file mode 100644
index 0000000000..5b6de7bb87
--- /dev/null
+++ b/include/linux/scmi_protocol.h
@@ -0,0 +1,654 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * SCMI Message Protocol driver header
+ *
+ * Copyright (C) 2018-2021 ARM Ltd.
+ */
+
+#ifndef _LINUX_SCMI_PROTOCOL_H
+#define _LINUX_SCMI_PROTOCOL_H
+
+#include <linux/bitfield.h>
+#include <driver.h>
+#include <linux/types.h>
+
+#define SCMI_MAX_STR_SIZE	16
+#define SCMI_MAX_NUM_RATES	16
+
+/**
+ * struct scmi_revision_info - version information structure
+ *
+ * @major_ver: Major ABI version. Change here implies risk of backward
+ *	compatibility break.
+ * @minor_ver: Minor ABI version. Change here implies new feature addition,
+ *	or compatible change in ABI.
+ * @num_protocols: Number of protocols that are implemented, excluding the
+ *	base protocol.
+ * @num_agents: Number of agents in the system.
+ * @impl_ver: A vendor-specific implementation version.
+ * @vendor_id: A vendor identifier(Null terminated ASCII string)
+ * @sub_vendor_id: A sub-vendor identifier(Null terminated ASCII string)
+ */
+struct scmi_revision_info {
+	u16 major_ver;
+	u16 minor_ver;
+	u8 num_protocols;
+	u8 num_agents;
+	u32 impl_ver;
+	char vendor_id[SCMI_MAX_STR_SIZE];
+	char sub_vendor_id[SCMI_MAX_STR_SIZE];
+};
+
+struct scmi_clock_info {
+	char name[SCMI_MAX_STR_SIZE];
+	bool rate_discrete;
+	union {
+		struct {
+			int num_rates;
+			u64 rates[SCMI_MAX_NUM_RATES];
+		} list;
+		struct {
+			u64 min_rate;
+			u64 max_rate;
+			u64 step_size;
+		} range;
+	};
+};
+
+struct scmi_handle;
+struct scmi_device;
+struct scmi_protocol_handle;
+
+/**
+ * struct scmi_clk_proto_ops - represents the various operations provided
+ *	by SCMI Clock Protocol
+ *
+ * @count_get: get the count of clocks provided by SCMI
+ * @info_get: get the information of the specified clock
+ * @rate_get: request the current clock rate of a clock
+ * @rate_set: set the clock rate of a clock
+ * @enable: enables the specified clock
+ * @disable: disables the specified clock
+ */
+struct scmi_clk_proto_ops {
+	int (*count_get)(const struct scmi_protocol_handle *ph);
+
+	const struct scmi_clock_info *(*info_get)
+		(const struct scmi_protocol_handle *ph, u32 clk_id);
+	int (*rate_get)(const struct scmi_protocol_handle *ph, u32 clk_id,
+			u64 *rate);
+	int (*rate_set)(const struct scmi_protocol_handle *ph, u32 clk_id,
+			u64 rate);
+	int (*enable)(const struct scmi_protocol_handle *ph, u32 clk_id);
+	int (*disable)(const struct scmi_protocol_handle *ph, u32 clk_id);
+};
+
+/**
+ * struct scmi_perf_proto_ops - represents the various operations provided
+ *	by SCMI Performance Protocol
+ *
+ * @limits_set: sets limits on the performance level of a domain
+ * @limits_get: gets limits on the performance level of a domain
+ * @level_set: sets the performance level of a domain
+ * @level_get: gets the performance level of a domain
+ * @device_domain_id: gets the scmi domain id for a given device_d
+ * @transition_latency_get: gets the DVFS transition latency for a given device_d
+ * @device_opps_add: adds all the OPPs for a given device_d
+ * @freq_set: sets the frequency for a given device_d using sustained frequency
+ *	to sustained performance level mapping
+ * @freq_get: gets the frequency for a given device_d using sustained frequency
+ *	to sustained performance level mapping
+ * @est_power_get: gets the estimated power cost for a given performance domain
+ *	at a given frequency
+ */
+struct scmi_perf_proto_ops {
+	int (*limits_set)(const struct scmi_protocol_handle *ph, u32 domain,
+			  u32 max_perf, u32 min_perf);
+	int (*limits_get)(const struct scmi_protocol_handle *ph, u32 domain,
+			  u32 *max_perf, u32 *min_perf);
+	int (*level_set)(const struct scmi_protocol_handle *ph, u32 domain,
+			 u32 level, bool poll);
+	int (*level_get)(const struct scmi_protocol_handle *ph, u32 domain,
+			 u32 *level, bool poll);
+	int (*device_domain_id)(struct device_d *dev);
+	int (*transition_latency_get)(const struct scmi_protocol_handle *ph,
+				      struct device_d *dev);
+	int (*device_opps_add)(const struct scmi_protocol_handle *ph,
+			       struct device_d *dev);
+	int (*freq_set)(const struct scmi_protocol_handle *ph, u32 domain,
+			unsigned long rate, bool poll);
+	int (*freq_get)(const struct scmi_protocol_handle *ph, u32 domain,
+			unsigned long *rate, bool poll);
+	int (*est_power_get)(const struct scmi_protocol_handle *ph, u32 domain,
+			     unsigned long *rate, unsigned long *power);
+	bool (*fast_switch_possible)(const struct scmi_protocol_handle *ph,
+				     struct device_d *dev);
+	bool (*power_scale_mw_get)(const struct scmi_protocol_handle *ph);
+};
+
+/**
+ * struct scmi_power_proto_ops - represents the various operations provided
+ *	by SCMI Power Protocol
+ *
+ * @num_domains_get: get the count of power domains provided by SCMI
+ * @name_get: gets the name of a power domain
+ * @state_set: sets the power state of a power domain
+ * @state_get: gets the power state of a power domain
+ */
+struct scmi_power_proto_ops {
+	int (*num_domains_get)(const struct scmi_protocol_handle *ph);
+	char *(*name_get)(const struct scmi_protocol_handle *ph, u32 domain);
+#define SCMI_POWER_STATE_TYPE_SHIFT	30
+#define SCMI_POWER_STATE_ID_MASK	(BIT(28) - 1)
+#define SCMI_POWER_STATE_PARAM(type, id) \
+	((((type) & BIT(0)) << SCMI_POWER_STATE_TYPE_SHIFT) | \
+		((id) & SCMI_POWER_STATE_ID_MASK))
+#define SCMI_POWER_STATE_GENERIC_ON	SCMI_POWER_STATE_PARAM(0, 0)
+#define SCMI_POWER_STATE_GENERIC_OFF	SCMI_POWER_STATE_PARAM(1, 0)
+	int (*state_set)(const struct scmi_protocol_handle *ph, u32 domain,
+			 u32 state);
+	int (*state_get)(const struct scmi_protocol_handle *ph, u32 domain,
+			 u32 *state);
+};
+
+/**
+ * scmi_sensor_reading  - represent a timestamped read
+ *
+ * Used by @reading_get_timestamped method.
+ *
+ * @value: The signed value sensor read.
+ * @timestamp: An unsigned timestamp for the sensor read, as provided by
+ *	       SCMI platform. Set to zero when not available.
+ */
+struct scmi_sensor_reading {
+	long long value;
+	unsigned long long timestamp;
+};
+
+/**
+ * scmi_range_attrs  - specifies a sensor or axis values' range
+ * @min_range: The minimum value which can be represented by the sensor/axis.
+ * @max_range: The maximum value which can be represented by the sensor/axis.
+ */
+struct scmi_range_attrs {
+	long long min_range;
+	long long max_range;
+};
+
+/**
+ * scmi_sensor_axis_info  - describes one sensor axes
+ * @id: The axes ID.
+ * @type: Axes type. Chosen amongst one of @enum scmi_sensor_class.
+ * @scale: Power-of-10 multiplier applied to the axis unit.
+ * @name: NULL-terminated string representing axes name as advertised by
+ *	  SCMI platform.
+ * @extended_attrs: Flag to indicate the presence of additional extended
+ *		    attributes for this axes.
+ * @resolution: Extended attribute representing the resolution of the axes.
+ *		Set to 0 if not reported by this axes.
+ * @exponent: Extended attribute representing the power-of-10 multiplier that
+ *	      is applied to the resolution field. Set to 0 if not reported by
+ *	      this axes.
+ * @attrs: Extended attributes representing minimum and maximum values
+ *	   measurable by this axes. Set to 0 if not reported by this sensor.
+ */
+struct scmi_sensor_axis_info {
+	unsigned int id;
+	unsigned int type;
+	int scale;
+	char name[SCMI_MAX_STR_SIZE];
+	bool extended_attrs;
+	unsigned int resolution;
+	int exponent;
+	struct scmi_range_attrs attrs;
+};
+
+/**
+ * scmi_sensor_intervals_info  - describes number and type of available update
+ * intervals
+ * @segmented: Flag for segmented intervals' representation. When True there
+ *	       will be exactly 3 intervals in @desc, with each entry
+ *	       representing a member of a segment in this order:
+ *	       {lowest update interval, highest update interval, step size}
+ * @count: Number of intervals described in @desc.
+ * @desc: Array of @count interval descriptor bitmask represented as detailed in
+ *	  the SCMI specification: it can be accessed using the accompanying
+ *	  macros.
+ * @prealloc_pool: A minimal preallocated pool of desc entries used to avoid
+ *		   lesser-than-64-bytes dynamic allocation for small @count
+ *		   values.
+ */
+struct scmi_sensor_intervals_info {
+	bool segmented;
+	unsigned int count;
+#define SCMI_SENS_INTVL_SEGMENT_LOW	0
+#define SCMI_SENS_INTVL_SEGMENT_HIGH	1
+#define SCMI_SENS_INTVL_SEGMENT_STEP	2
+	unsigned int *desc;
+#define SCMI_SENS_INTVL_GET_SECS(x)		FIELD_GET(GENMASK(20, 5), (x))
+#define SCMI_SENS_INTVL_GET_EXP(x)					\
+	({								\
+		int __signed_exp = FIELD_GET(GENMASK(4, 0), (x));	\
+									\
+		if (__signed_exp & BIT(4))				\
+			__signed_exp |= GENMASK(31, 5);			\
+		__signed_exp;						\
+	})
+#define SCMI_MAX_PREALLOC_POOL			16
+	unsigned int prealloc_pool[SCMI_MAX_PREALLOC_POOL];
+};
+
+/**
+ * struct scmi_sensor_info - represents information related to one of the
+ * available sensors.
+ * @id: Sensor ID.
+ * @type: Sensor type. Chosen amongst one of @enum scmi_sensor_class.
+ * @scale: Power-of-10 multiplier applied to the sensor unit.
+ * @num_trip_points: Number of maximum configurable trip points.
+ * @async: Flag for asynchronous read support.
+ * @update: Flag for continuouos update notification support.
+ * @timestamped: Flag for timestamped read support.
+ * @tstamp_scale: Power-of-10 multiplier applied to the sensor timestamps to
+ *		  represent it in seconds.
+ * @num_axis: Number of supported axis if any. Reported as 0 for scalar sensors.
+ * @axis: Pointer to an array of @num_axis descriptors.
+ * @intervals: Descriptor of available update intervals.
+ * @sensor_config: A bitmask reporting the current sensor configuration as
+ *		   detailed in the SCMI specification: it can accessed and
+ *		   modified through the accompanying macros.
+ * @name: NULL-terminated string representing sensor name as advertised by
+ *	  SCMI platform.
+ * @extended_scalar_attrs: Flag to indicate the presence of additional extended
+ *			   attributes for this sensor.
+ * @sensor_power: Extended attribute representing the average power
+ *		  consumed by the sensor in microwatts (uW) when it is active.
+ *		  Reported here only for scalar sensors.
+ *		  Set to 0 if not reported by this sensor.
+ * @resolution: Extended attribute representing the resolution of the sensor.
+ *		Reported here only for scalar sensors.
+ *		Set to 0 if not reported by this sensor.
+ * @exponent: Extended attribute representing the power-of-10 multiplier that is
+ *	      applied to the resolution field.
+ *	      Reported here only for scalar sensors.
+ *	      Set to 0 if not reported by this sensor.
+ * @scalar_attrs: Extended attributes representing minimum and maximum
+ *		  measurable values by this sensor.
+ *		  Reported here only for scalar sensors.
+ *		  Set to 0 if not reported by this sensor.
+ */
+struct scmi_sensor_info {
+	unsigned int id;
+	unsigned int type;
+	int scale;
+	unsigned int num_trip_points;
+	bool async;
+	bool update;
+	bool timestamped;
+	int tstamp_scale;
+	unsigned int num_axis;
+	struct scmi_sensor_axis_info *axis;
+	struct scmi_sensor_intervals_info intervals;
+	unsigned int sensor_config;
+#define SCMI_SENS_CFG_UPDATE_SECS_MASK		GENMASK(31, 16)
+#define SCMI_SENS_CFG_GET_UPDATE_SECS(x)				\
+	FIELD_GET(SCMI_SENS_CFG_UPDATE_SECS_MASK, (x))
+
+#define SCMI_SENS_CFG_UPDATE_EXP_MASK		GENMASK(15, 11)
+#define SCMI_SENS_CFG_GET_UPDATE_EXP(x)					\
+	({								\
+		int __signed_exp =					\
+			FIELD_GET(SCMI_SENS_CFG_UPDATE_EXP_MASK, (x));	\
+									\
+		if (__signed_exp & BIT(4))				\
+			__signed_exp |= GENMASK(31, 5);			\
+		__signed_exp;						\
+	})
+
+#define SCMI_SENS_CFG_ROUND_MASK		GENMASK(10, 9)
+#define SCMI_SENS_CFG_ROUND_AUTO		2
+#define SCMI_SENS_CFG_ROUND_UP			1
+#define SCMI_SENS_CFG_ROUND_DOWN		0
+
+#define SCMI_SENS_CFG_TSTAMP_ENABLED_MASK	BIT(1)
+#define SCMI_SENS_CFG_TSTAMP_ENABLE		1
+#define SCMI_SENS_CFG_TSTAMP_DISABLE		0
+#define SCMI_SENS_CFG_IS_TSTAMP_ENABLED(x)				\
+	FIELD_GET(SCMI_SENS_CFG_TSTAMP_ENABLED_MASK, (x))
+
+#define SCMI_SENS_CFG_SENSOR_ENABLED_MASK	BIT(0)
+#define SCMI_SENS_CFG_SENSOR_ENABLE		1
+#define SCMI_SENS_CFG_SENSOR_DISABLE		0
+	char name[SCMI_MAX_STR_SIZE];
+#define SCMI_SENS_CFG_IS_ENABLED(x)		FIELD_GET(BIT(0), (x))
+	bool extended_scalar_attrs;
+	unsigned int sensor_power;
+	unsigned int resolution;
+	int exponent;
+	struct scmi_range_attrs scalar_attrs;
+};
+
+/*
+ * Partial list from Distributed Management Task Force (DMTF) specification:
+ * DSP0249 (Platform Level Data Model specification)
+ */
+enum scmi_sensor_class {
+	NONE = 0x0,
+	UNSPEC = 0x1,
+	TEMPERATURE_C = 0x2,
+	TEMPERATURE_F = 0x3,
+	TEMPERATURE_K = 0x4,
+	VOLTAGE = 0x5,
+	CURRENT = 0x6,
+	POWER = 0x7,
+	ENERGY = 0x8,
+	CHARGE = 0x9,
+	VOLTAMPERE = 0xA,
+	NITS = 0xB,
+	LUMENS = 0xC,
+	LUX = 0xD,
+	CANDELAS = 0xE,
+	KPA = 0xF,
+	PSI = 0x10,
+	NEWTON = 0x11,
+	CFM = 0x12,
+	RPM = 0x13,
+	HERTZ = 0x14,
+	SECS = 0x15,
+	MINS = 0x16,
+	HOURS = 0x17,
+	DAYS = 0x18,
+	WEEKS = 0x19,
+	MILS = 0x1A,
+	INCHES = 0x1B,
+	FEET = 0x1C,
+	CUBIC_INCHES = 0x1D,
+	CUBIC_FEET = 0x1E,
+	METERS = 0x1F,
+	CUBIC_CM = 0x20,
+	CUBIC_METERS = 0x21,
+	LITERS = 0x22,
+	FLUID_OUNCES = 0x23,
+	RADIANS = 0x24,
+	STERADIANS = 0x25,
+	REVOLUTIONS = 0x26,
+	CYCLES = 0x27,
+	GRAVITIES = 0x28,
+	OUNCES = 0x29,
+	POUNDS = 0x2A,
+	FOOT_POUNDS = 0x2B,
+	OUNCE_INCHES = 0x2C,
+	GAUSS = 0x2D,
+	GILBERTS = 0x2E,
+	HENRIES = 0x2F,
+	FARADS = 0x30,
+	OHMS = 0x31,
+	SIEMENS = 0x32,
+	MOLES = 0x33,
+	BECQUERELS = 0x34,
+	PPM = 0x35,
+	DECIBELS = 0x36,
+	DBA = 0x37,
+	DBC = 0x38,
+	GRAYS = 0x39,
+	SIEVERTS = 0x3A,
+	COLOR_TEMP_K = 0x3B,
+	BITS = 0x3C,
+	BYTES = 0x3D,
+	WORDS = 0x3E,
+	DWORDS = 0x3F,
+	QWORDS = 0x40,
+	PERCENTAGE = 0x41,
+	PASCALS = 0x42,
+	COUNTS = 0x43,
+	GRAMS = 0x44,
+	NEWTON_METERS = 0x45,
+	HITS = 0x46,
+	MISSES = 0x47,
+	RETRIES = 0x48,
+	OVERRUNS = 0x49,
+	UNDERRUNS = 0x4A,
+	COLLISIONS = 0x4B,
+	PACKETS = 0x4C,
+	MESSAGES = 0x4D,
+	CHARS = 0x4E,
+	ERRORS = 0x4F,
+	CORRECTED_ERRS = 0x50,
+	UNCORRECTABLE_ERRS = 0x51,
+	SQ_MILS = 0x52,
+	SQ_INCHES = 0x53,
+	SQ_FEET = 0x54,
+	SQ_CM = 0x55,
+	SQ_METERS = 0x56,
+	RADIANS_SEC = 0x57,
+	BPM = 0x58,
+	METERS_SEC_SQUARED = 0x59,
+	METERS_SEC = 0x5A,
+	CUBIC_METERS_SEC = 0x5B,
+	MM_MERCURY = 0x5C,
+	RADIANS_SEC_SQUARED = 0x5D,
+	OEM_UNIT = 0xFF
+};
+
+/**
+ * struct scmi_sensor_proto_ops - represents the various operations provided
+ *	by SCMI Sensor Protocol
+ *
+ * @count_get: get the count of sensors provided by SCMI
+ * @info_get: get the information of the specified sensor
+ * @trip_point_config: selects and configures a trip-point of interest
+ * @reading_get: gets the current value of the sensor
+ * @reading_get_timestamped: gets the current value and timestamp, when
+ *			     available, of the sensor. (as of v3.0 spec)
+ *			     Supports multi-axis sensors for sensors which
+ *			     supports it and if the @reading array size of
+ *			     @count entry equals the sensor num_axis
+ * @config_get: Get sensor current configuration
+ * @config_set: Set sensor current configuration
+ */
+struct scmi_sensor_proto_ops {
+	int (*count_get)(const struct scmi_protocol_handle *ph);
+	const struct scmi_sensor_info *(*info_get)
+		(const struct scmi_protocol_handle *ph, u32 sensor_id);
+	int (*trip_point_config)(const struct scmi_protocol_handle *ph,
+				 u32 sensor_id, u8 trip_id, u64 trip_value);
+	int (*reading_get)(const struct scmi_protocol_handle *ph, u32 sensor_id,
+			   u64 *value);
+	int (*reading_get_timestamped)(const struct scmi_protocol_handle *ph,
+				       u32 sensor_id, u8 count,
+				       struct scmi_sensor_reading *readings);
+	int (*config_get)(const struct scmi_protocol_handle *ph,
+			  u32 sensor_id, u32 *sensor_config);
+	int (*config_set)(const struct scmi_protocol_handle *ph,
+			  u32 sensor_id, u32 sensor_config);
+};
+
+/**
+ * struct scmi_reset_proto_ops - represents the various operations provided
+ *	by SCMI Reset Protocol
+ *
+ * @num_domains_get: get the count of reset domains provided by SCMI
+ * @name_get: gets the name of a reset domain
+ * @latency_get: gets the reset latency for the specified reset domain
+ * @reset: resets the specified reset domain
+ * @assert: explicitly assert reset signal of the specified reset domain
+ * @deassert: explicitly deassert reset signal of the specified reset domain
+ */
+struct scmi_reset_proto_ops {
+	int (*num_domains_get)(const struct scmi_protocol_handle *ph);
+	char *(*name_get)(const struct scmi_protocol_handle *ph, u32 domain);
+	int (*latency_get)(const struct scmi_protocol_handle *ph, u32 domain);
+	int (*reset)(const struct scmi_protocol_handle *ph, u32 domain);
+	int (*assert)(const struct scmi_protocol_handle *ph, u32 domain);
+	int (*deassert)(const struct scmi_protocol_handle *ph, u32 domain);
+};
+
+/**
+ * struct scmi_voltage_info - describe one available SCMI Voltage Domain
+ *
+ * @id: the domain ID as advertised by the platform
+ * @segmented: defines the layout of the entries of array @levels_uv.
+ *	       - when True the entries are to be interpreted as triplets,
+ *	         each defining a segment representing a range of equally
+ *	         space voltages: <lowest_volts>, <highest_volt>, <step_uV>
+ *	       - when False the entries simply represent a single discrete
+ *	         supported voltage level
+ * @negative_volts_allowed: True if any of the entries of @levels_uv represent
+ *			    a negative voltage.
+ * @attributes: represents Voltage Domain advertised attributes
+ * @name: name assigned to the Voltage Domain by platform
+ * @num_levels: number of total entries in @levels_uv.
+ * @levels_uv: array of entries describing the available voltage levels for
+ *	       this domain.
+ */
+struct scmi_voltage_info {
+	unsigned int id;
+	bool segmented;
+	bool negative_volts_allowed;
+	unsigned int attributes;
+	char name[SCMI_MAX_STR_SIZE];
+	unsigned int num_levels;
+#define SCMI_VOLTAGE_SEGMENT_LOW	0
+#define SCMI_VOLTAGE_SEGMENT_HIGH	1
+#define SCMI_VOLTAGE_SEGMENT_STEP	2
+	int *levels_uv;
+};
+
+/**
+ * struct scmi_voltage_proto_ops - represents the various operations provided
+ * by SCMI Voltage Protocol
+ *
+ * @num_domains_get: get the count of voltage domains provided by SCMI
+ * @info_get: get the information of the specified domain
+ * @config_set: set the config for the specified domain
+ * @config_get: get the config of the specified domain
+ * @level_set: set the voltage level for the specified domain
+ * @level_get: get the voltage level of the specified domain
+ */
+struct scmi_voltage_proto_ops {
+	int (*num_domains_get)(const struct scmi_protocol_handle *ph);
+	const struct scmi_voltage_info __must_check *(*info_get)
+		(const struct scmi_protocol_handle *ph, u32 domain_id);
+	int (*config_set)(const struct scmi_protocol_handle *ph, u32 domain_id,
+			  u32 config);
+#define	SCMI_VOLTAGE_ARCH_STATE_OFF		0x0
+#define	SCMI_VOLTAGE_ARCH_STATE_ON		0x7
+	int (*config_get)(const struct scmi_protocol_handle *ph, u32 domain_id,
+			  u32 *config);
+	int (*level_set)(const struct scmi_protocol_handle *ph, u32 domain_id,
+			 u32 flags, s32 volt_uV);
+	int (*level_get)(const struct scmi_protocol_handle *ph, u32 domain_id,
+			 s32 *volt_uV);
+};
+
+/**
+ * struct scmi_handle - Handle returned to ARM SCMI clients for usage.
+ *
+ * @dev: pointer to the SCMI device_d
+ * @version: pointer to the structure containing SCMI version information
+ * @protocol_get: method to acquire a protocol and get specific
+ *		       operations and a dedicated protocol handler
+ */
+struct scmi_handle {
+	struct device_d *dev;
+	struct scmi_revision_info *version;
+
+	const void __must_check *
+		(*protocol_get)(struct scmi_device *sdev, u8 proto,
+				     struct scmi_protocol_handle **ph);
+};
+
+enum scmi_std_protocol {
+	SCMI_PROTOCOL_BASE = 0x10,
+	SCMI_PROTOCOL_POWER = 0x11,
+	SCMI_PROTOCOL_SYSTEM = 0x12,
+	SCMI_PROTOCOL_PERF = 0x13,
+	SCMI_PROTOCOL_CLOCK = 0x14,
+	SCMI_PROTOCOL_SENSOR = 0x15,
+	SCMI_PROTOCOL_RESET = 0x16,
+	SCMI_PROTOCOL_VOLTAGE = 0x17,
+};
+
+enum scmi_system_events {
+	SCMI_SYSTEM_SHUTDOWN,
+	SCMI_SYSTEM_COLDRESET,
+	SCMI_SYSTEM_WARMRESET,
+	SCMI_SYSTEM_POWERUP,
+	SCMI_SYSTEM_SUSPEND,
+	SCMI_SYSTEM_MAX
+};
+
+struct scmi_device {
+	u8 protocol_id;
+	const char *name;
+	struct device_d dev;
+	struct scmi_handle *handle;
+};
+
+#define to_scmi_dev(d) container_of(d, struct scmi_device, dev)
+
+struct scmi_device *
+scmi_device_alloc(struct device_node *np, struct device_d *parent, int protocol,
+		  const char *name);
+void scmi_device_destroy(struct scmi_device *scmi_dev);
+
+struct scmi_device_id {
+	u8 protocol_id;
+	const char *name;
+};
+
+struct scmi_driver {
+	const char *name;
+	int (*probe)(struct scmi_device *sdev);
+	void (*remove)(struct scmi_device *sdev);
+	const struct scmi_device_id *id_table;
+
+	struct driver_d driver;
+};
+
+#define to_scmi_driver(d) container_of(d, struct scmi_driver, driver)
+
+#if IS_REACHABLE(CONFIG_ARM_SCMI_PROTOCOL)
+int scmi_driver_register(struct scmi_driver *driver);
+#else
+static inline int
+scmi_driver_register(struct scmi_driver *driver)
+{
+	return -EINVAL;
+}
+
+#endif /* CONFIG_ARM_SCMI_PROTOCOL */
+
+#define scmi_register(driver) \
+	scmi_driver_register(driver)
+
+/**
+ * coredevice_scmi_driver() - Helper macro for registering a scmi driver
+ * @__scmi_driver: scmi_driver structure
+ *
+ * Helper macro for scmi drivers to set up proper module init / exit
+ * functions.  Replaces module_init() and module_exit() and keeps people from
+ * printing pointless things to the kernel log when their driver is loaded.
+ */
+#define coredevice_scmi_driver(__scmi_driver)	\
+	register_driver_macro(coredevice,scmi,__scmi_driver)
+
+#define core_scmi_driver(__scmi_driver)	\
+	register_driver_macro(core,scmi,__scmi_driver)
+
+/**
+ * module_scmi_protocol() - Helper macro for registering a scmi protocol
+ * @__scmi_protocol: scmi_protocol structure
+ *
+ * Helper macro for scmi drivers to set up proper module init / exit
+ * functions.  Replaces module_init() and module_exit() and keeps people from
+ * printing pointless things to the kernel log when their driver is loaded.
+ */
+#define module_scmi_protocol(__scmi_protocol)	\
+	module_driver(__scmi_protocol,		\
+		      scmi_protocol_register, scmi_protocol_unregister)
+
+struct scmi_protocol;
+int scmi_protocol_register(const struct scmi_protocol *proto);
+void scmi_protocol_unregister(const struct scmi_protocol *proto);
+
+#endif /* _LINUX_SCMI_PROTOCOL_H */
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 348770a3a2..eb14c58e34 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -103,4 +103,7 @@ static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
 	return calloc(n, size);
 }
 
+#define kstrdup_const(str, flags) strdup(str)
+#define kfree_const(ptr) kfree((void *)ptr)
+
 #endif /* _LINUX_SLAB_H */