drivers/pinctrl/pinctrl-zynqmp.c

// SPDX-License-Identifier: GPL-2.0
/*
 * ZynqMP pin controller
 *
 * Copyright (C) 2020, 2021 Xilinx, Inc.
 *
 * Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
 * Rajan Vaja <rajan.vaja@xilinx.com>
 */

#include <dt-bindings/pinctrl/pinctrl-zynqmp.h>

#include <linux/init.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>

#include <linux/firmware/xlnx-zynqmp.h>

#include <linux/pinctrl/pinconf-generic.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>

#include "core.h"
#include "pinctrl-utils.h"

#define ZYNQMP_PIN_PREFIX			"MIO"
#define PINCTRL_GET_FUNC_NAME_RESP_LEN		16
#define MAX_FUNC_NAME_LEN			16
#define MAX_GROUP_PIN				50
#define MAX_PIN_GROUPS				50
#define END_OF_FUNCTIONS			"END_OF_FUNCTIONS"
#define NUM_GROUPS_PER_RESP			6

#define PINCTRL_GET_FUNC_GROUPS_RESP_LEN	12
#define PINCTRL_GET_PIN_GROUPS_RESP_LEN		12
#define NA_GROUP				0xFFFF
#define RESERVED_GROUP				0xFFFE

#define DRIVE_STRENGTH_2MA	2
#define DRIVE_STRENGTH_4MA	4
#define DRIVE_STRENGTH_8MA	8
#define DRIVE_STRENGTH_12MA	12

/**
 * struct zynqmp_pmux_function - a pinmux function
 * @name:	Name of the pin mux function
 * @groups:	List of pin groups for this function
 * @ngroups:	Number of entries in @groups
 * @node:	Firmware node matching with the function
 *
 * This structure holds information about pin control function
 * and function group names supporting that function.
 */
struct zynqmp_pmux_function {
	char name[MAX_FUNC_NAME_LEN];
	const char * const *groups;
	unsigned int ngroups;
};

/**
 * struct zynqmp_pinctrl - driver data
 * @pctrl:	Pin control device
 * @groups:	Pin groups
 * @ngroups:	Number of @groups
 * @funcs:	Pin mux functions
 * @nfuncs:	Number of @funcs
 *
 * This struct is stored as driver data and used to retrieve
 * information regarding pin control functions, groups and
 * group pins.
 */
struct zynqmp_pinctrl {
	struct pinctrl_dev *pctrl;
	const struct zynqmp_pctrl_group *groups;
	unsigned int ngroups;
	const struct zynqmp_pmux_function *funcs;
	unsigned int nfuncs;
};

/**
 * struct zynqmp_pctrl_group - Pin control group info
 * @name:	Group name
 * @pins:	Group pin numbers
 * @npins:	Number of pins in the group
 */
struct zynqmp_pctrl_group {
	const char *name;
	unsigned int pins[MAX_GROUP_PIN];
	unsigned int npins;
};

static struct pinctrl_desc zynqmp_desc;

static int zynqmp_pctrl_get_groups_count(struct pinctrl_dev *pctldev)
{
	struct zynqmp_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

	return pctrl->ngroups;
}

static const char *zynqmp_pctrl_get_group_name(struct pinctrl_dev *pctldev,
					       unsigned int selector)
{
	struct zynqmp_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

	return pctrl->groups[selector].name;
}

static int zynqmp_pctrl_get_group_pins(struct pinctrl_dev *pctldev,
				       unsigned int selector,
				       const unsigned int **pins,
				       unsigned int *npins)
{
	struct zynqmp_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

	*pins = pctrl->groups[selector].pins;
	*npins = pctrl->groups[selector].npins;

	return 0;
}

static const struct pinctrl_ops zynqmp_pctrl_ops = {
	.get_groups_count = zynqmp_pctrl_get_groups_count,
	.get_group_name = zynqmp_pctrl_get_group_name,
	.get_group_pins = zynqmp_pctrl_get_group_pins,
	.dt_node_to_map = pinconf_generic_dt_node_to_map_all,
	.dt_free_map = pinctrl_utils_free_map,
};

static int zynqmp_pinmux_request_pin(struct pinctrl_dev *pctldev,
				     unsigned int pin)
{
	int ret;

	ret = zynqmp_pm_pinctrl_request(pin);
	if (ret) {
		dev_err(pctldev->dev, "request failed for pin %u\n", pin);
		return ret;
	}

	return 0;
}

static int zynqmp_pmux_get_functions_count(struct pinctrl_dev *pctldev)
{
	struct zynqmp_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

	return pctrl->nfuncs;
}

static const char *zynqmp_pmux_get_function_name(struct pinctrl_dev *pctldev,
						 unsigned int selector)
{
	struct zynqmp_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

	return pctrl->funcs[selector].name;
}

/**
 * zynqmp_pmux_get_function_groups() - Get groups for the function
 * @pctldev:	Pincontrol device pointer.
 * @selector:	Function ID
 * @groups:	Group names.
 * @num_groups:	Number of function groups.
 *
 * Get function's group count and group names.
 *
 * Return: 0
 */
static int zynqmp_pmux_get_function_groups(struct pinctrl_dev *pctldev,
					   unsigned int selector,
					   const char * const **groups,
					   unsigned * const num_groups)
{
	struct zynqmp_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);

	*groups = pctrl->funcs[selector].groups;
	*num_groups = pctrl->funcs[selector].ngroups;

	return 0;
}

/**
 * zynqmp_pinmux_set_mux() - Set requested function for the group
 * @pctldev:	Pincontrol device pointer.
 * @function:	Function ID.
 * @group:	Group ID.
 *
 * Loop through all pins of the group and call firmware API
 * to set requested function for all pins in the group.
 *
 * Return: 0 on success else error code.
 */
static int zynqmp_pinmux_set_mux(struct pinctrl_dev *pctldev,
				 unsigned int function,
				 unsigned int group)
{
	struct zynqmp_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
	const struct zynqmp_pctrl_group *pgrp = &pctrl->groups[group];
	int ret, i;

	for (i = 0; i < pgrp->npins; i++) {
		unsigned int pin = pgrp->pins[i];

		ret = zynqmp_pm_pinctrl_set_function(pin, function);
		if (ret) {
			dev_err(pctldev->dev, "set mux failed for pin %u\n",
				pin);
			return ret;
		}
	}

	return 0;
}

static int zynqmp_pinmux_release_pin(struct pinctrl_dev *pctldev,
				     unsigned int pin)
{
	int ret;

	ret = zynqmp_pm_pinctrl_release(pin);
	if (ret) {
		dev_err(pctldev->dev, "free pin failed for pin %u\n",
			pin);
		return ret;
	}

	return 0;
}

static const struct pinmux_ops zynqmp_pinmux_ops = {
	.request = zynqmp_pinmux_request_pin,
	.get_functions_count = zynqmp_pmux_get_functions_count,
	.get_function_name = zynqmp_pmux_get_function_name,
	.get_function_groups = zynqmp_pmux_get_function_groups,
	.set_mux = zynqmp_pinmux_set_mux,
	.free = zynqmp_pinmux_release_pin,
};

/**
 * zynqmp_pinconf_cfg_get() - get config value for the pin
 * @pctldev:	Pin control device pointer.
 * @pin:	Pin number.
 * @config:	Value of config param.
 *
 * Get value of the requested configuration parameter for the
 * given pin.
 *
 * Return: 0 on success else error code.
 */
static int zynqmp_pinconf_cfg_get(struct pinctrl_dev *pctldev,
				  unsigned int pin,
				  unsigned long *config)
{
	unsigned int arg, param = pinconf_to_config_param(*config);
	int ret;

	switch (param) {
	case PIN_CONFIG_SLEW_RATE:
		param = PM_PINCTRL_CONFIG_SLEW_RATE;
		ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg);
		break;
	case PIN_CONFIG_BIAS_PULL_UP:
		param = PM_PINCTRL_CONFIG_PULL_CTRL;
		ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg);
		if (arg != PM_PINCTRL_BIAS_PULL_UP)
			return -EINVAL;

		arg = 1;
		break;
	case PIN_CONFIG_BIAS_PULL_DOWN:
		param = PM_PINCTRL_CONFIG_PULL_CTRL;
		ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg);
		if (arg != PM_PINCTRL_BIAS_PULL_DOWN)
			return -EINVAL;

		arg = 1;
		break;
	case PIN_CONFIG_BIAS_DISABLE:
		param = PM_PINCTRL_CONFIG_BIAS_STATUS;
		ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg);
		if (arg != PM_PINCTRL_BIAS_DISABLE)
			return -EINVAL;

		arg = 1;
		break;
	case PIN_CONFIG_POWER_SOURCE:
		param = PM_PINCTRL_CONFIG_VOLTAGE_STATUS;
		ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg);
		break;
	case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
		param = PM_PINCTRL_CONFIG_SCHMITT_CMOS;
		ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg);
		break;
	case PIN_CONFIG_DRIVE_STRENGTH:
		param = PM_PINCTRL_CONFIG_DRIVE_STRENGTH;
		ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg);
		switch (arg) {
		case PM_PINCTRL_DRIVE_STRENGTH_2MA:
			arg = DRIVE_STRENGTH_2MA;
			break;
		case PM_PINCTRL_DRIVE_STRENGTH_4MA:
			arg = DRIVE_STRENGTH_4MA;
			break;
		case PM_PINCTRL_DRIVE_STRENGTH_8MA:
			arg = DRIVE_STRENGTH_8MA;
			break;
		case PM_PINCTRL_DRIVE_STRENGTH_12MA:
			arg = DRIVE_STRENGTH_12MA;
			break;
		default:
			/* Invalid drive strength */
			dev_warn(pctldev->dev,
				 "Invalid drive strength for pin %d\n",
				 pin);
			return -EINVAL;
		}
		break;
	default:
		ret = -ENOTSUPP;
		break;
	}

	if (ret)
		return ret;

	param = pinconf_to_config_param(*config);
	*config = pinconf_to_config_packed(param, arg);

	return 0;
}

/**
 * zynqmp_pinconf_cfg_set() - Set requested config for the pin
 * @pctldev:		Pincontrol device pointer.
 * @pin:		Pin number.
 * @configs:		Configuration to set.
 * @num_configs:	Number of configurations.
 *
 * Loop through all configurations and call firmware API
 * to set requested configurations for the pin.
 *
 * Return: 0 on success else error code.
 */
static int zynqmp_pinconf_cfg_set(struct pinctrl_dev *pctldev,
				  unsigned int pin, unsigned long *configs,
				  unsigned int num_configs)
{
	int i, ret;

	for (i = 0; i < num_configs; i++) {
		unsigned int param = pinconf_to_config_param(configs[i]);
		unsigned int arg = pinconf_to_config_argument(configs[i]);
		unsigned int value;

		switch (param) {
		case PIN_CONFIG_SLEW_RATE:
			param = PM_PINCTRL_CONFIG_SLEW_RATE;
			ret = zynqmp_pm_pinctrl_set_config(pin, param, arg);
			break;
		case PIN_CONFIG_BIAS_PULL_UP:
			param = PM_PINCTRL_CONFIG_PULL_CTRL;
			arg = PM_PINCTRL_BIAS_PULL_UP;
			ret = zynqmp_pm_pinctrl_set_config(pin, param, arg);
			break;
		case PIN_CONFIG_BIAS_PULL_DOWN:
			param = PM_PINCTRL_CONFIG_PULL_CTRL;
			arg = PM_PINCTRL_BIAS_PULL_DOWN;
			ret = zynqmp_pm_pinctrl_set_config(pin, param, arg);
			break;
		case PIN_CONFIG_BIAS_DISABLE:
			param = PM_PINCTRL_CONFIG_BIAS_STATUS;
			arg = PM_PINCTRL_BIAS_DISABLE;
			ret = zynqmp_pm_pinctrl_set_config(pin, param, arg);
			break;
		case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
			param = PM_PINCTRL_CONFIG_SCHMITT_CMOS;
			ret = zynqmp_pm_pinctrl_set_config(pin, param, arg);
			break;
		case PIN_CONFIG_DRIVE_STRENGTH:
			switch (arg) {
			case DRIVE_STRENGTH_2MA:
				value = PM_PINCTRL_DRIVE_STRENGTH_2MA;
				break;
			case DRIVE_STRENGTH_4MA:
				value = PM_PINCTRL_DRIVE_STRENGTH_4MA;
				break;
			case DRIVE_STRENGTH_8MA:
				value = PM_PINCTRL_DRIVE_STRENGTH_8MA;
				break;
			case DRIVE_STRENGTH_12MA:
				value = PM_PINCTRL_DRIVE_STRENGTH_12MA;
				break;
			default:
				/* Invalid drive strength */
				dev_warn(pctldev->dev,
					 "Invalid drive strength for pin %d\n",
					 pin);
				return -EINVAL;
			}

			param = PM_PINCTRL_CONFIG_DRIVE_STRENGTH;
			ret = zynqmp_pm_pinctrl_set_config(pin, param, value);
			break;
		case PIN_CONFIG_POWER_SOURCE:
			param = PM_PINCTRL_CONFIG_VOLTAGE_STATUS;
			ret = zynqmp_pm_pinctrl_get_config(pin, param, &value);

			if (arg != value)
				dev_warn(pctldev->dev,
					 "Invalid IO Standard requested for pin %d\n",
					 pin);

			break;
		case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
			param = PM_PINCTRL_CONFIG_TRI_STATE;
			arg = PM_PINCTRL_TRI_STATE_ENABLE;
			ret = zynqmp_pm_pinctrl_set_config(pin, param, arg);
			break;
		case PIN_CONFIG_MODE_LOW_POWER:
			/*
			 * These cases are mentioned in dts but configurable
			 * registers are unknown. So falling through to ignore
			 * boot time warnings as of now.
			 */
			ret = 0;
			break;
		case PIN_CONFIG_OUTPUT_ENABLE:
			param = PM_PINCTRL_CONFIG_TRI_STATE;
			arg = PM_PINCTRL_TRI_STATE_DISABLE;
			ret = zynqmp_pm_pinctrl_set_config(pin, param, arg);
			break;
		default:
			dev_warn(pctldev->dev,
				 "unsupported configuration parameter '%u'\n",
				 param);
			ret = -ENOTSUPP;
			break;
		}

		param = pinconf_to_config_param(configs[i]);
		arg = pinconf_to_config_argument(configs[i]);
		if (ret)
			dev_warn(pctldev->dev,
				 "failed to set: pin %u param %u value %u\n",
				 pin, param, arg);
	}

	return 0;
}

/**
 * zynqmp_pinconf_group_set() - Set requested config for the group
 * @pctldev:		Pincontrol device pointer.
 * @selector:		Group ID.
 * @configs:		Configuration to set.
 * @num_configs:	Number of configurations.
 *
 * Call function to set configs for each pin in the group.
 *
 * Return: 0 on success else error code.
 */
static int zynqmp_pinconf_group_set(struct pinctrl_dev *pctldev,
				    unsigned int selector,
				    unsigned long *configs,
				    unsigned int num_configs)
{
	int i, ret;
	struct zynqmp_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
	const struct zynqmp_pctrl_group *pgrp = &pctrl->groups[selector];

	for (i = 0; i < pgrp->npins; i++) {
		ret = zynqmp_pinconf_cfg_set(pctldev, pgrp->pins[i], configs,
					     num_configs);
		if (ret)
			return ret;
	}

	return 0;
}

static const struct pinconf_ops zynqmp_pinconf_ops = {
	.is_generic = true,
	.pin_config_get = zynqmp_pinconf_cfg_get,
	.pin_config_set = zynqmp_pinconf_cfg_set,
	.pin_config_group_set = zynqmp_pinconf_group_set,
};

static struct pinctrl_desc zynqmp_desc = {
	.name = "zynqmp_pinctrl",
	.owner = THIS_MODULE,
	.pctlops = &zynqmp_pctrl_ops,
	.pmxops = &zynqmp_pinmux_ops,
	.confops = &zynqmp_pinconf_ops,
};

static int zynqmp_pinctrl_get_function_groups(u32 fid, u32 index, u16 *groups)
{
	struct zynqmp_pm_query_data qdata = {0};
	u32 payload[PAYLOAD_ARG_CNT];
	int ret;

	qdata.qid = PM_QID_PINCTRL_GET_FUNCTION_GROUPS;
	qdata.arg1 = fid;
	qdata.arg2 = index;

	ret = zynqmp_pm_query_data(qdata, payload);
	if (ret)
		return ret;

	memcpy(groups, &payload[1], PINCTRL_GET_FUNC_GROUPS_RESP_LEN);

	return 0;
}

static int zynqmp_pinctrl_get_func_num_groups(u32 fid, unsigned int *ngroups)
{
	struct zynqmp_pm_query_data qdata = {0};
	u32 payload[PAYLOAD_ARG_CNT];
	int ret;

	qdata.qid = PM_QID_PINCTRL_GET_NUM_FUNCTION_GROUPS;
	qdata.arg1 = fid;

	ret = zynqmp_pm_query_data(qdata, payload);
	if (ret)
		return ret;

	*ngroups = payload[1];

	return 0;
}

/**
 * zynqmp_pinctrl_prepare_func_groups() - prepare function and groups data
 * @dev:	Device pointer.
 * @fid:	Function ID.
 * @func:	Function data.
 * @groups:	Groups data.
 *
 * Query firmware to get group IDs for each function. Firmware returns
 * group IDs. Based on the group index for the function, group names in
 * the function are stored. For example, the first group in "eth0" function
 * is named as "eth0_0" and the second group as "eth0_1" and so on.
 *
 * Based on the group ID received from the firmware, function stores name of
 * the group for that group ID. For example, if "eth0" first group ID
 * is x, groups[x] name will be stored as "eth0_0".
 *
 * Once done for each function, each function would have its group names
 * and each group would also have their names.
 *
 * Return: 0 on success else error code.
 */
static int zynqmp_pinctrl_prepare_func_groups(struct device *dev, u32 fid,
					      struct zynqmp_pmux_function *func,
					      struct zynqmp_pctrl_group *groups)
{
	u16 resp[NUM_GROUPS_PER_RESP] = {0};
	const char **fgroups;
	int ret, index, i;

	fgroups = devm_kcalloc(dev, func->ngroups, sizeof(*fgroups), GFP_KERNEL);
	if (!fgroups)
		return -ENOMEM;

	for (index = 0; index < func->ngroups; index += NUM_GROUPS_PER_RESP) {
		ret = zynqmp_pinctrl_get_function_groups(fid, index, resp);
		if (ret)
			return ret;

		for (i = 0; i < NUM_GROUPS_PER_RESP; i++) {
			if (resp[i] == NA_GROUP)
				goto done;

			if (resp[i] == RESERVED_GROUP)
				continue;

			fgroups[index + i] = devm_kasprintf(dev, GFP_KERNEL,
							    "%s_%d_grp",
							    func->name,
							    index + i);
			if (!fgroups[index + i])
				return -ENOMEM;

			groups[resp[i]].name = devm_kasprintf(dev, GFP_KERNEL,
							      "%s_%d_grp",
							      func->name,
							      index + i);
			if (!groups[resp[i]].name)
				return -ENOMEM;
		}
	}
done:
	func->groups = fgroups;

	return 0;
}

static void zynqmp_pinctrl_get_function_name(u32 fid, char *name)
{
	struct zynqmp_pm_query_data qdata = {0};
	u32 payload[PAYLOAD_ARG_CNT];

	qdata.qid = PM_QID_PINCTRL_GET_FUNCTION_NAME;
	qdata.arg1 = fid;

	/*
	 * Name of the function is maximum 16 bytes and cannot
	 * accommodate the return value in SMC buffers, hence ignoring
	 * the return value for this specific qid.
	 */
	zynqmp_pm_query_data(qdata, payload);
	memcpy(name, payload, PINCTRL_GET_FUNC_NAME_RESP_LEN);
}

static int zynqmp_pinctrl_get_num_functions(unsigned int *nfuncs)
{
	struct zynqmp_pm_query_data qdata = {0};
	u32 payload[PAYLOAD_ARG_CNT];
	int ret;

	qdata.qid = PM_QID_PINCTRL_GET_NUM_FUNCTIONS;

	ret = zynqmp_pm_query_data(qdata, payload);
	if (ret)
		return ret;

	*nfuncs = payload[1];

	return 0;
}

static int zynqmp_pinctrl_get_pin_groups(u32 pin, u32 index, u16 *groups)
{
	struct zynqmp_pm_query_data qdata = {0};
	u32 payload[PAYLOAD_ARG_CNT];
	int ret;

	qdata.qid = PM_QID_PINCTRL_GET_PIN_GROUPS;
	qdata.arg1 = pin;
	qdata.arg2 = index;

	ret = zynqmp_pm_query_data(qdata, payload);
	if (ret)
		return ret;

	memcpy(groups, &payload[1], PINCTRL_GET_PIN_GROUPS_RESP_LEN);

	return 0;
}

static void zynqmp_pinctrl_group_add_pin(struct zynqmp_pctrl_group *group,
					 unsigned int pin)
{
	group->pins[group->npins++] = pin;
}

/**
 * zynqmp_pinctrl_create_pin_groups() - assign pins to respective groups
 * @dev:	Device pointer.
 * @groups:	Groups data.
 * @pin:	Pin number.
 *
 * Query firmware to get groups available for the given pin.
 * Based on the firmware response(group IDs for the pin), add
 * pin number to the respective group's pin array.
 *
 * Once all pins are queries, each group would have its number
 * of pins and pin numbers data.
 *
 * Return: 0 on success else error code.
 */
static int zynqmp_pinctrl_create_pin_groups(struct device *dev,
					    struct zynqmp_pctrl_group *groups,
					    unsigned int pin)
{
	u16 resp[NUM_GROUPS_PER_RESP] = {0};
	int ret, i, index = 0;

	do {
		ret = zynqmp_pinctrl_get_pin_groups(pin, index, resp);
		if (ret)
			return ret;

		for (i = 0; i < NUM_GROUPS_PER_RESP; i++) {
			if (resp[i] == NA_GROUP)
				return ret;

			if (resp[i] == RESERVED_GROUP)
				continue;

			zynqmp_pinctrl_group_add_pin(&groups[resp[i]], pin);
		}
		index += NUM_GROUPS_PER_RESP;
	} while (index <= MAX_PIN_GROUPS);

	return 0;
}

/**
 * zynqmp_pinctrl_prepare_group_pins() - prepare each group's pin data
 * @dev:	Device pointer.
 * @groups:	Groups data.
 * @ngroups:	Number of groups.
 *
 * Prepare pin number and number of pins data for each pins.
 *
 * Return: 0 on success else error code.
 */
static int zynqmp_pinctrl_prepare_group_pins(struct device *dev,
					     struct zynqmp_pctrl_group *groups,
					     unsigned int ngroups)
{
	unsigned int pin;
	int ret;

	for (pin = 0; pin < zynqmp_desc.npins; pin++) {
		ret = zynqmp_pinctrl_create_pin_groups(dev, groups, pin);
		if (ret)
			return ret;
	}

	return 0;
}

/**
 * zynqmp_pinctrl_prepare_function_info() - prepare function info
 * @dev:	Device pointer.
 * @pctrl:	Pin control driver data.
 *
 * Query firmware for functions, groups and pin information and
 * prepare pin control driver data.
 *
 * Query number of functions and number of function groups (number
 * of groups in the given function) to allocate required memory buffers
 * for functions and groups. Once buffers are allocated to store
 * functions and groups data, query and store required information
 * (number of groups and group names for each function, number of
 * pins and pin numbers for each group).
 *
 * Return: 0 on success else error code.
 */
static int zynqmp_pinctrl_prepare_function_info(struct device *dev,
						struct zynqmp_pinctrl *pctrl)
{
	struct zynqmp_pmux_function *funcs;
	struct zynqmp_pctrl_group *groups;
	int ret, i;

	ret = zynqmp_pinctrl_get_num_functions(&pctrl->nfuncs);
	if (ret)
		return ret;

	funcs = devm_kcalloc(dev, pctrl->nfuncs, sizeof(*funcs), GFP_KERNEL);
	if (!funcs)
		return -ENOMEM;

	for (i = 0; i < pctrl->nfuncs; i++) {
		zynqmp_pinctrl_get_function_name(i, funcs[i].name);

		ret = zynqmp_pinctrl_get_func_num_groups(i, &funcs[i].ngroups);
		if (ret)
			return ret;

		pctrl->ngroups += funcs[i].ngroups;
	}

	groups = devm_kcalloc(dev, pctrl->ngroups, sizeof(*groups), GFP_KERNEL);
	if (!groups)
		return -ENOMEM;

	for (i = 0; i < pctrl->nfuncs; i++) {
		ret = zynqmp_pinctrl_prepare_func_groups(dev, i, &funcs[i],
							 groups);
		if (ret)
			return ret;
	}

	ret = zynqmp_pinctrl_prepare_group_pins(dev, groups, pctrl->ngroups);
	if (ret)
		return ret;

	pctrl->funcs = funcs;
	pctrl->groups = groups;

	return 0;
}

static int zynqmp_pinctrl_get_num_pins(unsigned int *npins)
{
	struct zynqmp_pm_query_data qdata = {0};
	u32 payload[PAYLOAD_ARG_CNT];
	int ret;

	qdata.qid = PM_QID_PINCTRL_GET_NUM_PINS;

	ret = zynqmp_pm_query_data(qdata, payload);
	if (ret)
		return ret;

	*npins = payload[1];

	return 0;
}

/**
 * zynqmp_pinctrl_prepare_pin_desc() - prepare pin description info
 * @dev:		Device pointer.
 * @zynqmp_pins:	Pin information.
 * @npins:		Number of pins.
 *
 * Query number of pins information from firmware and prepare pin
 * description containing pin number and pin name.
 *
 * Return: 0 on success else error code.
 */
static int zynqmp_pinctrl_prepare_pin_desc(struct device *dev,
					   const struct pinctrl_pin_desc
					   **zynqmp_pins,
					   unsigned int *npins)
{
	struct pinctrl_pin_desc *pins, *pin;
	int ret;
	int i;

	ret = zynqmp_pinctrl_get_num_pins(npins);
	if (ret)
		return ret;

	pins = devm_kcalloc(dev, *npins, sizeof(*pins), GFP_KERNEL);
	if (!pins)
		return -ENOMEM;

	for (i = 0; i < *npins; i++) {
		pin = &pins[i];
		pin->number = i;
		pin->name = devm_kasprintf(dev, GFP_KERNEL, "%s%d",
					   ZYNQMP_PIN_PREFIX, i);
		if (!pin->name)
			return -ENOMEM;
	}

	*zynqmp_pins = pins;

	return 0;
}

static int zynqmp_pinctrl_probe(struct platform_device *pdev)
{
	struct zynqmp_pinctrl *pctrl;
	int ret;

	pctrl = devm_kzalloc(&pdev->dev, sizeof(*pctrl), GFP_KERNEL);
	if (!pctrl)
		return -ENOMEM;

	ret = zynqmp_pinctrl_prepare_pin_desc(&pdev->dev,
					      &zynqmp_desc.pins,
					      &zynqmp_desc.npins);
	if (ret) {
		dev_err(&pdev->dev, "pin desc prepare fail with %d\n", ret);
		return ret;
	}

	ret = zynqmp_pinctrl_prepare_function_info(&pdev->dev, pctrl);
	if (ret) {
		dev_err(&pdev->dev, "function info prepare fail with %d\n", ret);
		return ret;
	}

	pctrl->pctrl = devm_pinctrl_register(&pdev->dev, &zynqmp_desc, pctrl);
	if (IS_ERR(pctrl->pctrl))
		return PTR_ERR(pctrl->pctrl);

	platform_set_drvdata(pdev, pctrl);

	return ret;
}

static const struct of_device_id zynqmp_pinctrl_of_match[] = {
	{ .compatible = "xlnx,zynqmp-pinctrl" },
	{ }
};
MODULE_DEVICE_TABLE(of, zynqmp_pinctrl_of_match);

static struct platform_driver zynqmp_pinctrl_driver = {
	.driver = {
		.name = "zynqmp-pinctrl",
		.of_match_table = zynqmp_pinctrl_of_match,
	},
	.probe = zynqmp_pinctrl_probe,
};
module_platform_driver(zynqmp_pinctrl_driver);

MODULE_AUTHOR("Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>");
MODULE_DESCRIPTION("ZynqMP Pin Controller Driver");
MODULE_LICENSE("GPL v2");