// SPDX-License-Identifier: GPL-2.0
/*
 * Zynq UltraScale+ MPSoC clock controller
 *
 *  Copyright (C) 2016-2018 Xilinx
 *
 * Based on drivers/clk/zynq/clkc.c
 */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
#include <linux/string.h>

#include "clk-zynqmp.h"

#define MAX_PARENT                      100
#define MAX_NODES                       6
#define MAX_NAME_LEN                    50

#define CLK_TYPE_SHIFT                  2

#define PM_API_PAYLOAD_LEN              3

#define NA_PARENT                       0xFFFFFFFF
#define DUMMY_PARENT                    0xFFFFFFFE

#define CLK_TYPE_FIELD_LEN              4
#define CLK_TOPOLOGY_NODE_OFFSET        16
#define NODES_PER_RESP                  3

#define CLK_TYPE_FIELD_MASK             0xF
#define CLK_FLAG_FIELD_MASK             GENMASK(21, 8)
#define CLK_TYPE_FLAG_FIELD_MASK        GENMASK(31, 24)

#define CLK_PARENTS_ID_LEN              16
#define CLK_PARENTS_ID_MASK             0xFFFF

/* Flags for parents */
#define PARENT_CLK_SELF                 0
#define PARENT_CLK_NODE1                1
#define PARENT_CLK_NODE2                2
#define PARENT_CLK_NODE3                3
#define PARENT_CLK_NODE4                4
#define PARENT_CLK_EXTERNAL             5

#define END_OF_CLK_NAME                 "END_OF_CLK"
#define END_OF_TOPOLOGY_NODE            1
#define END_OF_PARENTS                  1
#define RESERVED_CLK_NAME               ""

#define CLK_VALID_MASK                  0x1

enum clk_type {
        CLK_TYPE_OUTPUT,
        CLK_TYPE_EXTERNAL,
};

/**
 * struct clock_parent - Clock parent
 * @name:       Parent name
 * @id:         Parent clock ID
 * @flag:       Parent flags
 */
struct clock_parent {
        char name[MAX_NAME_LEN];
        int id;
        u32 flag;
};

/**
 * struct zynqmp_clock - Clock
 * @clk_name:           Clock name
 * @valid:              Validity flag of clock
 * @type:               Clock type (Output/External)
 * @node:               Clock topology nodes
 * @num_nodes:          Number of nodes present in topology
 * @parent:             Parent of clock
 * @num_parents:        Number of parents of clock
 */
struct zynqmp_clock {
        char clk_name[MAX_NAME_LEN];
        u32 valid;
        enum clk_type type;
        struct clock_topology node[MAX_NODES];
        u32 num_nodes;
        struct clock_parent parent[MAX_PARENT];
        u32 num_parents;
};

static const char clk_type_postfix[][10] = {
        [TYPE_INVALID] = "",
        [TYPE_MUX] = "_mux",
        [TYPE_GATE] = "",
        [TYPE_DIV1] = "_div1",
        [TYPE_DIV2] = "_div2",
        [TYPE_FIXEDFACTOR] = "_ff",
        [TYPE_PLL] = ""
};

static struct clk_hw *(* const clk_topology[]) (const char *name, u32 clk_id,
                                        const char * const *parents,
                                        u8 num_parents,
                                        const struct clock_topology *nodes)
                                        = {
        [TYPE_INVALID] = NULL,
        [TYPE_MUX] = zynqmp_clk_register_mux,
        [TYPE_PLL] = zynqmp_clk_register_pll,
        [TYPE_FIXEDFACTOR] = zynqmp_clk_register_fixed_factor,
        [TYPE_DIV1] = zynqmp_clk_register_divider,
        [TYPE_DIV2] = zynqmp_clk_register_divider,
        [TYPE_GATE] = zynqmp_clk_register_gate
};

static struct zynqmp_clock *clock;
static struct clk_hw_onecell_data *zynqmp_data;
static unsigned int clock_max_idx;
static const struct zynqmp_eemi_ops *eemi_ops;

/**
 * zynqmp_is_valid_clock() - Check whether clock is valid or not
 * @clk_id:     Clock index
 *
 * Return: 1 if clock is valid, 0 if clock is invalid else error code
 */
static inline int zynqmp_is_valid_clock(u32 clk_id)
{
        if (clk_id >= clock_max_idx)
                return -ENODEV;

        return clock[clk_id].valid;
}

/**
 * zynqmp_get_clock_name() - Get name of clock from Clock index
 * @clk_id:     Clock index
 * @clk_name:   Name of clock
 *
 * Return: 0 on success else error code
 */
static int zynqmp_get_clock_name(u32 clk_id, char *clk_name)
{
        int ret;

        ret = zynqmp_is_valid_clock(clk_id);
        if (ret == 1) {
                strncpy(clk_name, clock[clk_id].clk_name, MAX_NAME_LEN);
                return 0;
        }

        return ret == 0 ? -EINVAL : ret;
}

/**
 * zynqmp_get_clock_type() - Get type of clock
 * @clk_id:     Clock index
 * @type:       Clock type: CLK_TYPE_OUTPUT or CLK_TYPE_EXTERNAL
 *
 * Return: 0 on success else error code
 */
static int zynqmp_get_clock_type(u32 clk_id, u32 *type)
{
        int ret;

        ret = zynqmp_is_valid_clock(clk_id);
        if (ret == 1) {
                *type = clock[clk_id].type;
                return 0;
        }

        return ret == 0 ? -EINVAL : ret;
}

/**
 * zynqmp_pm_clock_get_num_clocks() - Get number of clocks in system
 * @nclocks:    Number of clocks in system/board.
 *
 * Call firmware API to get number of clocks.
 *
 * Return: 0 on success else error code.
 */
static int zynqmp_pm_clock_get_num_clocks(u32 *nclocks)
{
        struct zynqmp_pm_query_data qdata = {0};
        u32 ret_payload[PAYLOAD_ARG_CNT];
        int ret;

        qdata.qid = PM_QID_CLOCK_GET_NUM_CLOCKS;

        ret = eemi_ops->query_data(qdata, ret_payload);
        *nclocks = ret_payload[1];

        return ret;
}

/**
 * zynqmp_pm_clock_get_name() - Get the name of clock for given id
 * @clock_id:   ID of the clock to be queried
 * @name:       Name of given clock
 *
 * This function is used to get name of clock specified by given
 * clock ID.
 *
 * Return: Returns 0, in case of error name would be 0
 */
static int zynqmp_pm_clock_get_name(u32 clock_id, char *name)
{
        struct zynqmp_pm_query_data qdata = {0};
        u32 ret_payload[PAYLOAD_ARG_CNT];

        qdata.qid = PM_QID_CLOCK_GET_NAME;
        qdata.arg1 = clock_id;

        eemi_ops->query_data(qdata, ret_payload);
        memcpy(name, ret_payload, CLK_GET_NAME_RESP_LEN);

        return 0;
}

/**
 * zynqmp_pm_clock_get_topology() - Get the topology of clock for given id
 * @clock_id:   ID of the clock to be queried
 * @index:      Node index of clock topology
 * @topology:   Buffer to store nodes in topology and flags
 *
 * This function is used to get topology information for the clock
 * specified by given clock ID.
 *
 * This API will return 3 node of topology with a single response. To get
 * other nodes, master should call same API in loop with new
 * index till error is returned. E.g First call should have
 * index 0 which will return nodes 0,1 and 2. Next call, index
 * should be 3 which will return nodes 3,4 and 5 and so on.
 *
 * Return: 0 on success else error+reason
 */
static int zynqmp_pm_clock_get_topology(u32 clock_id, u32 index, u32 *topology)
{
        struct zynqmp_pm_query_data qdata = {0};
        u32 ret_payload[PAYLOAD_ARG_CNT];
        int ret;

        qdata.qid = PM_QID_CLOCK_GET_TOPOLOGY;
        qdata.arg1 = clock_id;
        qdata.arg2 = index;

        ret = eemi_ops->query_data(qdata, ret_payload);
        memcpy(topology, &ret_payload[1], CLK_GET_TOPOLOGY_RESP_WORDS * 4);

        return ret;
}

/**
 * zynqmp_clk_register_fixed_factor() - Register fixed factor with the
 *                                      clock framework
 * @name:               Name of this clock
 * @clk_id:             Clock ID
 * @parents:            Name of this clock's parents
 * @num_parents:        Number of parents
 * @nodes:              Clock topology node
 *
 * Return: clock hardware to the registered clock
 */
struct clk_hw *zynqmp_clk_register_fixed_factor(const char *name, u32 clk_id,
                                        const char * const *parents,
                                        u8 num_parents,
                                        const struct clock_topology *nodes)
{
        u32 mult, div;
        struct clk_hw *hw;
        struct zynqmp_pm_query_data qdata = {0};
        u32 ret_payload[PAYLOAD_ARG_CNT];
        int ret;

        qdata.qid = PM_QID_CLOCK_GET_FIXEDFACTOR_PARAMS;
        qdata.arg1 = clk_id;

        ret = eemi_ops->query_data(qdata, ret_payload);
        if (ret)
                return ERR_PTR(ret);

        mult = ret_payload[1];
        div = ret_payload[2];

        hw = clk_hw_register_fixed_factor(NULL, name,
                                          parents[0],
                                          nodes->flag, mult,
                                          div);

        return hw;
}

/**
 * zynqmp_pm_clock_get_parents() - Get the first 3 parents of clock for given id
 * @clock_id:   Clock ID
 * @index:      Parent index
 * @parents:    3 parents of the given clock
 *
 * This function is used to get 3 parents for the clock specified by
 * given clock ID.
 *
 * This API will return 3 parents with a single response. To get
 * other parents, master should call same API in loop with new
 * parent index till error is returned. E.g First call should have
 * index 0 which will return parents 0,1 and 2. Next call, index
 * should be 3 which will return parent 3,4 and 5 and so on.
 *
 * Return: 0 on success else error+reason
 */
static int zynqmp_pm_clock_get_parents(u32 clock_id, u32 index, u32 *parents)
{
        struct zynqmp_pm_query_data qdata = {0};
        u32 ret_payload[PAYLOAD_ARG_CNT];
        int ret;

        qdata.qid = PM_QID_CLOCK_GET_PARENTS;
        qdata.arg1 = clock_id;
        qdata.arg2 = index;

        ret = eemi_ops->query_data(qdata, ret_payload);
        memcpy(parents, &ret_payload[1], CLK_GET_PARENTS_RESP_WORDS * 4);

        return ret;
}

/**
 * zynqmp_pm_clock_get_attributes() - Get the attributes of clock for given id
 * @clock_id:   Clock ID
 * @attr:       Clock attributes
 *
 * This function is used to get clock's attributes(e.g. valid, clock type, etc).
 *
 * Return: 0 on success else error+reason
 */
static int zynqmp_pm_clock_get_attributes(u32 clock_id, u32 *attr)
{
        struct zynqmp_pm_query_data qdata = {0};
        u32 ret_payload[PAYLOAD_ARG_CNT];
        int ret;

        qdata.qid = PM_QID_CLOCK_GET_ATTRIBUTES;
        qdata.arg1 = clock_id;

        ret = eemi_ops->query_data(qdata, ret_payload);
        memcpy(attr, &ret_payload[1], CLK_GET_ATTR_RESP_WORDS * 4);

        return ret;
}

/**
 * __zynqmp_clock_get_topology() - Get topology data of clock from firmware
 *                                 response data
 * @topology:           Clock topology
 * @data:               Clock topology data received from firmware
 * @nnodes:             Number of nodes
 *
 * Return: 0 on success else error+reason
 */
static int __zynqmp_clock_get_topology(struct clock_topology *topology,
                                       u32 *data, u32 *nnodes)
{
        int i;

        for (i = 0; i < PM_API_PAYLOAD_LEN; i++) {
                if (!(data[i] & CLK_TYPE_FIELD_MASK))
                        return END_OF_TOPOLOGY_NODE;
                topology[*nnodes].type = data[i] & CLK_TYPE_FIELD_MASK;
                topology[*nnodes].flag = FIELD_GET(CLK_FLAG_FIELD_MASK,
                                                   data[i]);
                topology[*nnodes].type_flag =
                                FIELD_GET(CLK_TYPE_FLAG_FIELD_MASK, data[i]);
                (*nnodes)++;
        }

        return 0;
}

/**
 * zynqmp_clock_get_topology() - Get topology of clock from firmware using
 *                               PM_API
 * @clk_id:             Clock index
 * @topology:           Clock topology
 * @num_nodes:          Number of nodes
 *
 * Return: 0 on success else error+reason
 */
static int zynqmp_clock_get_topology(u32 clk_id,
                                     struct clock_topology *topology,
                                     u32 *num_nodes)
{
        int j, ret;
        u32 pm_resp[PM_API_PAYLOAD_LEN] = {0};

        *num_nodes = 0;
        for (j = 0; j <= MAX_NODES; j += 3) {
                ret = zynqmp_pm_clock_get_topology(clk_id, j, pm_resp);
                if (ret)
                        return ret;
                ret = __zynqmp_clock_get_topology(topology, pm_resp, num_nodes);
                if (ret == END_OF_TOPOLOGY_NODE)
                        return 0;
        }

        return 0;
}

/**
 * __zynqmp_clock_get_topology() - Get parents info of clock from firmware
 *                                 response data
 * @parents:            Clock parents
 * @data:               Clock parents data received from firmware
 * @nparent:            Number of parent
 *
 * Return: 0 on success else error+reason
 */
static int __zynqmp_clock_get_parents(struct clock_parent *parents, u32 *data,
                                      u32 *nparent)
{
        int i;
        struct clock_parent *parent;

        for (i = 0; i < PM_API_PAYLOAD_LEN; i++) {
                if (data[i] == NA_PARENT)
                        return END_OF_PARENTS;

                parent = &parents[i];
                parent->id = data[i] & CLK_PARENTS_ID_MASK;
                if (data[i] == DUMMY_PARENT) {
                        strcpy(parent->name, "dummy_name");
                        parent->flag = 0;
                } else {
                        parent->flag = data[i] >> CLK_PARENTS_ID_LEN;
                        if (zynqmp_get_clock_name(parent->id, parent->name))
                                continue;
                }
                *nparent += 1;
        }

        return 0;
}

/**
 * zynqmp_clock_get_parents() - Get parents info from firmware using PM_API
 * @clk_id:             Clock index
 * @parents:            Clock parents
 * @num_parents:        Total number of parents
 *
 * Return: 0 on success else error+reason
 */
static int zynqmp_clock_get_parents(u32 clk_id, struct clock_parent *parents,
                                    u32 *num_parents)
{
        int j = 0, ret;
        u32 pm_resp[PM_API_PAYLOAD_LEN] = {0};

        *num_parents = 0;
        do {
                /* Get parents from firmware */
                ret = zynqmp_pm_clock_get_parents(clk_id, j, pm_resp);
                if (ret)
                        return ret;

                ret = __zynqmp_clock_get_parents(&parents[j], pm_resp,
                                                 num_parents);
                if (ret == END_OF_PARENTS)
                        return 0;
                j += PM_API_PAYLOAD_LEN;
        } while (*num_parents <= MAX_PARENT);

        return 0;
}

/**
 * zynqmp_get_parent_list() - Create list of parents name
 * @np:                 Device node
 * @clk_id:             Clock index
 * @parent_list:        List of parent's name
 * @num_parents:        Total number of parents
 *
 * Return: 0 on success else error+reason
 */
static int zynqmp_get_parent_list(struct device_node *np, u32 clk_id,
                                  const char **parent_list, u32 *num_parents)
{
        int i = 0, ret;
        u32 total_parents = clock[clk_id].num_parents;
        struct clock_topology *clk_nodes;
        struct clock_parent *parents;

        clk_nodes = clock[clk_id].node;
        parents = clock[clk_id].parent;

        for (i = 0; i < total_parents; i++) {
                if (!parents[i].flag) {
                        parent_list[i] = parents[i].name;
                } else if (parents[i].flag == PARENT_CLK_EXTERNAL) {
                        ret = of_property_match_string(np, "clock-names",
                                                       parents[i].name);
                        if (ret < 0)
                                strcpy(parents[i].name, "dummy_name");
                        parent_list[i] = parents[i].name;
                } else {
                        strcat(parents[i].name,
                               clk_type_postfix[clk_nodes[parents[i].flag - 1].
                               type]);
                        parent_list[i] = parents[i].name;
                }
        }

        *num_parents = total_parents;
        return 0;
}

/**
 * zynqmp_register_clk_topology() - Register clock topology
 * @clk_id:             Clock index
 * @clk_name:           Clock Name
 * @num_parents:        Total number of parents
 * @parent_names:       List of parents name
 *
 * Return: Returns either clock hardware or error+reason
 */
static struct clk_hw *zynqmp_register_clk_topology(int clk_id, char *clk_name,
                                                   int num_parents,
                                                   const char **parent_names)
{
        int j;
        u32 num_nodes;
        char *clk_out = NULL;
        struct clock_topology *nodes;
        struct clk_hw *hw = NULL;

        nodes = clock[clk_id].node;
        num_nodes = clock[clk_id].num_nodes;

        for (j = 0; j < num_nodes; j++) {
                /*
                 * Clock name received from firmware is output clock name.
                 * Intermediate clock names are postfixed with type of clock.
                 */
                if (j != (num_nodes - 1)) {
                        clk_out = kasprintf(GFP_KERNEL, "%s%s", clk_name,
                                            clk_type_postfix[nodes[j].type]);
                } else {
                        clk_out = kasprintf(GFP_KERNEL, "%s", clk_name);
                }

                if (!clk_topology[nodes[j].type])
                        continue;

                hw = (*clk_topology[nodes[j].type])(clk_out, clk_id,
                                                    parent_names,
                                                    num_parents,
                                                    &nodes[j]);
                if (IS_ERR(hw))
                        pr_warn_once("%s() %s register fail with %ld\n",
                                     __func__, clk_name, PTR_ERR(hw));

                parent_names[0] = clk_out;
        }
        kfree(clk_out);
        return hw;
}

/**
 * zynqmp_register_clocks() - Register clocks
 * @np:         Device node
 *
 * Return: 0 on success else error code
 */
static int zynqmp_register_clocks(struct device_node *np)
{
        int ret;
        u32 i, total_parents = 0, type = 0;
        const char *parent_names[MAX_PARENT];

        for (i = 0; i < clock_max_idx; i++) {
                char clk_name[MAX_NAME_LEN];

                /* get clock name, continue to next clock if name not found */
                if (zynqmp_get_clock_name(i, clk_name))
                        continue;

                /* Check if clock is valid and output clock.
                 * Do not register invalid or external clock.
                 */
                ret = zynqmp_get_clock_type(i, &type);
                if (ret || type != CLK_TYPE_OUTPUT)
                        continue;

                /* Get parents of clock*/
                if (zynqmp_get_parent_list(np, i, parent_names,
                                           &total_parents)) {
                        WARN_ONCE(1, "No parents found for %s\n",
                                  clock[i].clk_name);
                        continue;
                }

                zynqmp_data->hws[i] =
                        zynqmp_register_clk_topology(i, clk_name,
                                                     total_parents,
                                                     parent_names);
        }

        for (i = 0; i < clock_max_idx; i++) {
                if (IS_ERR(zynqmp_data->hws[i])) {
                        pr_err("Zynq Ultrascale+ MPSoC clk %s: register failed with %ld\n",
                               clock[i].clk_name, PTR_ERR(zynqmp_data->hws[i]));
                        WARN_ON(1);
                }
        }
        return 0;
}

/**
 * zynqmp_get_clock_info() - Get clock information from firmware using PM_API
 */
static void zynqmp_get_clock_info(void)
{
        int i, ret;
        u32 attr, type = 0;

        for (i = 0; i < clock_max_idx; i++) {
                zynqmp_pm_clock_get_name(i, clock[i].clk_name);
                if (!strcmp(clock[i].clk_name, RESERVED_CLK_NAME))
                        continue;

                ret = zynqmp_pm_clock_get_attributes(i, &attr);
                if (ret)
                        continue;

                clock[i].valid = attr & CLK_VALID_MASK;
                clock[i].type = attr >> CLK_TYPE_SHIFT ? CLK_TYPE_EXTERNAL :
                                                        CLK_TYPE_OUTPUT;
        }

        /* Get topology of all clock */
        for (i = 0; i < clock_max_idx; i++) {
                ret = zynqmp_get_clock_type(i, &type);
                if (ret || type != CLK_TYPE_OUTPUT)
                        continue;

                ret = zynqmp_clock_get_topology(i, clock[i].node,
                                                &clock[i].num_nodes);
                if (ret)
                        continue;

                ret = zynqmp_clock_get_parents(i, clock[i].parent,
                                               &clock[i].num_parents);
                if (ret)
                        continue;
        }
}

/**
 * zynqmp_clk_setup() - Setup the clock framework and register clocks
 * @np:         Device node
 *
 * Return: 0 on success else error code
 */
static int zynqmp_clk_setup(struct device_node *np)
{
        int ret;

        ret = zynqmp_pm_clock_get_num_clocks(&clock_max_idx);
        if (ret)
                return ret;

        zynqmp_data = kzalloc(struct_size(zynqmp_data, hws, clock_max_idx),
                              GFP_KERNEL);
        if (!zynqmp_data)
                return -ENOMEM;

        clock = kcalloc(clock_max_idx, sizeof(*clock), GFP_KERNEL);
        if (!clock) {
                kfree(zynqmp_data);
                return -ENOMEM;
        }

        zynqmp_get_clock_info();
        zynqmp_register_clocks(np);

        zynqmp_data->num = clock_max_idx;
        of_clk_add_hw_provider(np, of_clk_hw_onecell_get, zynqmp_data);

        return 0;
}

static int zynqmp_clock_probe(struct platform_device *pdev)
{
        int ret;
        struct device *dev = &pdev->dev;

        eemi_ops = zynqmp_pm_get_eemi_ops();
        if (!eemi_ops)
                return -ENXIO;

        ret = zynqmp_clk_setup(dev->of_node);

        return ret;
}

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

static struct platform_driver zynqmp_clock_driver = {
        .driver = {
                .name = "zynqmp_clock",
                .of_match_table = zynqmp_clock_of_match,
        },
        .probe = zynqmp_clock_probe,
};
module_platform_driver(zynqmp_clock_driver);