path: root/drivers/firmware/arm_scmi/pinctrl.c

// SPDX-License-Identifier: GPL-2.0
/*
 * System Control and Management Interface (SCMI) Pinctrl Protocol
 *
 * Copyright (C) 2024 EPAM
 * Copyright 2024 NXP
 */

#include <asm/byteorder.h>
#include <linux/bits.h>
#include <linux/bitfield.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/scmi_protocol.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/types.h>

#include "common.h"
#include "protocols.h"

/* Updated only after ALL the mandatory features for that version are merged */
#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x10000

#define GET_GROUPS_NR(x)	le32_get_bits((x), GENMASK(31, 16))
#define GET_PINS_NR(x)		le32_get_bits((x), GENMASK(15, 0))
#define GET_FUNCTIONS_NR(x)	le32_get_bits((x), GENMASK(15, 0))

#define EXT_NAME_FLAG(x)	le32_get_bits((x), BIT(31))
#define NUM_ELEMS(x)		le32_get_bits((x), GENMASK(15, 0))

#define REMAINING(x)		le32_get_bits((x), GENMASK(31, 16))
#define RETURNED(x)		le32_get_bits((x), GENMASK(11, 0))

#define CONFIG_FLAG_MASK	GENMASK(19, 18)
#define SELECTOR_MASK		GENMASK(17, 16)
#define SKIP_CONFIGS_MASK	GENMASK(15, 8)
#define CONFIG_TYPE_MASK	GENMASK(7, 0)

enum scmi_pinctrl_protocol_cmd {
	PINCTRL_ATTRIBUTES = 0x3,
	PINCTRL_LIST_ASSOCIATIONS = 0x4,
	PINCTRL_SETTINGS_GET = 0x5,
	PINCTRL_SETTINGS_CONFIGURE = 0x6,
	PINCTRL_REQUEST = 0x7,
	PINCTRL_RELEASE = 0x8,
	PINCTRL_NAME_GET = 0x9,
	PINCTRL_SET_PERMISSIONS = 0xa,
};

struct scmi_msg_settings_conf {
	__le32 identifier;
	__le32 function_id;
	__le32 attributes;
	__le32 configs[];
};

struct scmi_msg_settings_get {
	__le32 identifier;
	__le32 attributes;
};

struct scmi_resp_settings_get {
	__le32 function_selected;
	__le32 num_configs;
	__le32 configs[];
};

struct scmi_msg_pinctrl_protocol_attributes {
	__le32 attributes_low;
	__le32 attributes_high;
};

struct scmi_msg_pinctrl_attributes {
	__le32 identifier;
	__le32 flags;
};

struct scmi_resp_pinctrl_attributes {
	__le32 attributes;
	u8 name[SCMI_SHORT_NAME_MAX_SIZE];
};

struct scmi_msg_pinctrl_list_assoc {
	__le32 identifier;
	__le32 flags;
	__le32 index;
};

struct scmi_resp_pinctrl_list_assoc {
	__le32 flags;
	__le16 array[];
};

struct scmi_msg_request {
	__le32 identifier;
	__le32 flags;
};

struct scmi_group_info {
	char name[SCMI_MAX_STR_SIZE];
	bool present;
	u32 *group_pins;
	u32 nr_pins;
};

struct scmi_function_info {
	char name[SCMI_MAX_STR_SIZE];
	bool present;
	u32 *groups;
	u32 nr_groups;
};

struct scmi_pin_info {
	char name[SCMI_MAX_STR_SIZE];
	bool present;
};

struct scmi_pinctrl_info {
	u32 version;
	int nr_groups;
	int nr_functions;
	int nr_pins;
	struct scmi_group_info *groups;
	struct scmi_function_info *functions;
	struct scmi_pin_info *pins;
};

static int scmi_pinctrl_attributes_get(const struct scmi_protocol_handle *ph,
				       struct scmi_pinctrl_info *pi)
{
	int ret;
	struct scmi_xfer *t;
	struct scmi_msg_pinctrl_protocol_attributes *attr;

	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0, sizeof(*attr), &t);
	if (ret)
		return ret;

	attr = t->rx.buf;

	ret = ph->xops->do_xfer(ph, t);
	if (!ret) {
		pi->nr_functions = GET_FUNCTIONS_NR(attr->attributes_high);
		pi->nr_groups = GET_GROUPS_NR(attr->attributes_low);
		pi->nr_pins = GET_PINS_NR(attr->attributes_low);
		if (pi->nr_pins == 0) {
			dev_warn(ph->dev, "returned zero pins\n");
			ret = -EINVAL;
		}
	}

	ph->xops->xfer_put(ph, t);
	return ret;
}

static int scmi_pinctrl_count_get(const struct scmi_protocol_handle *ph,
				  enum scmi_pinctrl_selector_type type)
{
	struct scmi_pinctrl_info *pi = ph->get_priv(ph);

	switch (type) {
	case PIN_TYPE:
		return pi->nr_pins;
	case GROUP_TYPE:
		return pi->nr_groups;
	case FUNCTION_TYPE:
		return pi->nr_functions;
	default:
		return -EINVAL;
	}
}

static int scmi_pinctrl_validate_id(const struct scmi_protocol_handle *ph,
				    u32 selector,
				    enum scmi_pinctrl_selector_type type)
{
	int value;

	value = scmi_pinctrl_count_get(ph, type);
	if (value < 0)
		return value;

	if (selector >= value || value == 0)
		return -EINVAL;

	return 0;
}

static int scmi_pinctrl_attributes(const struct scmi_protocol_handle *ph,
				   enum scmi_pinctrl_selector_type type,
				   u32 selector, char *name,
				   u32 *n_elems)
{
	int ret;
	struct scmi_xfer *t;
	struct scmi_msg_pinctrl_attributes *tx;
	struct scmi_resp_pinctrl_attributes *rx;
	bool ext_name_flag;

	if (!name)