// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2018, The Linux Foundation. All rights reserved.
 */

#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <soc/qcom/cmd-db.h>
#include <soc/qcom/rpmh.h>

#include <dt-bindings/clock/qcom,rpmh.h>

#define CLK_RPMH_ARC_EN_OFFSET          0
#define CLK_RPMH_VRM_EN_OFFSET          4

#define BCM_TCS_CMD_COMMIT_MASK         0x40000000
#define BCM_TCS_CMD_VALID_SHIFT         29
#define BCM_TCS_CMD_VOTE_MASK           0x3fff
#define BCM_TCS_CMD_VOTE_SHIFT          0

#define BCM_TCS_CMD(valid, vote)                                \
        (BCM_TCS_CMD_COMMIT_MASK |                              \
        ((valid) << BCM_TCS_CMD_VALID_SHIFT) |                  \
        ((vote & BCM_TCS_CMD_VOTE_MASK)                         \
        << BCM_TCS_CMD_VOTE_SHIFT))

/**
 * struct bcm_db - Auxiliary data pertaining to each Bus Clock Manager(BCM)
 * @unit: divisor used to convert Hz value to an RPMh msg
 * @width: multiplier used to convert Hz value to an RPMh msg
 * @vcd: virtual clock domain that this bcm belongs to
 * @reserved: reserved to pad the struct
 */
struct bcm_db {
        __le32 unit;
        __le16 width;
        u8 vcd;
        u8 reserved;
};

/**
 * struct clk_rpmh - individual rpmh clock data structure
 * @hw:                 handle between common and hardware-specific interfaces
 * @res_name:           resource name for the rpmh clock
 * @div:                clock divider to compute the clock rate
 * @res_addr:           base address of the rpmh resource within the RPMh
 * @res_on_val:         rpmh clock enable value
 * @state:              rpmh clock requested state
 * @aggr_state:         rpmh clock aggregated state
 * @last_sent_aggr_state: rpmh clock last aggr state sent to RPMh
 * @valid_state_mask:   mask to determine the state of the rpmh clock
 * @unit:               divisor to convert rate to rpmh msg in magnitudes of Khz
 * @dev:                device to which it is attached
 * @peer:               pointer to the clock rpmh sibling
 */
struct clk_rpmh {
        struct clk_hw hw;
        const char *res_name;
        u8 div;
        u32 res_addr;
        u32 res_on_val;
        u32 state;
        u32 aggr_state;
        u32 last_sent_aggr_state;
        u32 valid_state_mask;
        u32 unit;
        struct device *dev;
        struct clk_rpmh *peer;
};

struct clk_rpmh_desc {
        struct clk_hw **clks;
        size_t num_clks;
};

static DEFINE_MUTEX(rpmh_clk_lock);

#define __DEFINE_CLK_RPMH(_platform, _name, _name_active, _res_name,    \
                          _res_en_offset, _res_on, _div)                \
        static struct clk_rpmh _platform##_##_name_active;              \
        static struct clk_rpmh _platform##_##_name = {                  \
                .res_name = _res_name,                                  \
                .res_addr = _res_en_offset,                             \
                .res_on_val = _res_on,                                  \
                .div = _div,                                            \
                .peer = &_platform##_##_name_active,                    \
                .valid_state_mask = (BIT(RPMH_WAKE_ONLY_STATE) |        \
                                      BIT(RPMH_ACTIVE_ONLY_STATE) |     \
                                      BIT(RPMH_SLEEP_STATE)),           \
                .hw.init = &(struct clk_init_data){                     \
                        .ops = &clk_rpmh_ops,                           \
                        .name = #_name,                                 \
                        .parent_names = (const char *[]){ "xo_board" }, \
                        .num_parents = 1,                               \
                },                                                      \
        };                                                              \
        static struct clk_rpmh _platform##_##_name_active = {           \
                .res_name = _res_name,                                  \
                .res_addr = _res_en_offset,                             \
                .res_on_val = _res_on,                                  \
                .div = _div,                                            \
                .peer = &_platform##_##_name,                           \
                .valid_state_mask = (BIT(RPMH_WAKE_ONLY_STATE) |        \
                                        BIT(RPMH_ACTIVE_ONLY_STATE)),   \
                .hw.init = &(struct clk_init_data){                     \
                        .ops = &clk_rpmh_ops,                           \
                        .name = #_name_active,                          \
                        .parent_names = (const char *[]){ "xo_board" }, \
                        .num_parents = 1,                               \
                },                                                      \
        }

#define DEFINE_CLK_RPMH_ARC(_platform, _name, _name_active, _res_name,  \
                            _res_on, _div)                              \
        __DEFINE_CLK_RPMH(_platform, _name, _name_active, _res_name,    \
                          CLK_RPMH_ARC_EN_OFFSET, _res_on, _div)

#define DEFINE_CLK_RPMH_VRM(_platform, _name, _name_active, _res_name,  \
                                _div)                                   \
        __DEFINE_CLK_RPMH(_platform, _name, _name_active, _res_name,    \
                          CLK_RPMH_VRM_EN_OFFSET, 1, _div)

#define DEFINE_CLK_RPMH_BCM(_platform, _name, _res_name)                \
        static struct clk_rpmh _platform##_##_name = {                  \
                .res_name = _res_name,                                  \
                .valid_state_mask = BIT(RPMH_ACTIVE_ONLY_STATE),        \
                .div = 1,                                               \
                .hw.init = &(struct clk_init_data){                     \
                        .ops = &clk_rpmh_bcm_ops,                       \
                        .name = #_name,                                 \
                },                                                      \
        }

static inline struct clk_rpmh *to_clk_rpmh(struct clk_hw *_hw)
{
        return container_of(_hw, struct clk_rpmh, hw);
}

static inline bool has_state_changed(struct clk_rpmh *c, u32 state)
{
        return (c->last_sent_aggr_state & BIT(state))
                != (c->aggr_state & BIT(state));
}

static int clk_rpmh_send_aggregate_command(struct clk_rpmh *c)
{
        struct tcs_cmd cmd = { 0 };
        u32 cmd_state, on_val;
        enum rpmh_state state = RPMH_SLEEP_STATE;
        int ret;

        cmd.addr = c->res_addr;
        cmd_state = c->aggr_state;
        on_val = c->res_on_val;

        for (; state <= RPMH_ACTIVE_ONLY_STATE; state++) {
                if (has_state_changed(c, state)) {
                        if (cmd_state & BIT(state))
                                cmd.data = on_val;

                        ret = rpmh_write_async(c->dev, state, &cmd, 1);
                        if (ret) {
                                dev_err(c->dev, "set %s state of %s failed: (%d)\n",
                                        !state ? "sleep" :
                                        state == RPMH_WAKE_ONLY_STATE   ?
                                        "wake" : "active", c->res_name, ret);
                                return ret;
                        }
                }
        }

        c->last_sent_aggr_state = c->aggr_state;
        c->peer->last_sent_aggr_state =  c->last_sent_aggr_state;

        return 0;
}

/*
 * Update state and aggregate state values based on enable value.
 */
static int clk_rpmh_aggregate_state_send_command(struct clk_rpmh *c,
                                                bool enable)
{
        int ret;

        /* Nothing required to be done if already off or on */
        if (enable == c->state)
                return 0;

        c->state = enable ? c->valid_state_mask : 0;
        c->aggr_state = c->state | c->peer->state;
        c->peer->aggr_state = c->aggr_state;

        ret = clk_rpmh_send_aggregate_command(c);
        if (!ret)
                return 0;

        if (ret && enable)
                c->state = 0;
        else if (ret)
                c->state = c->valid_state_mask;

        WARN(1, "clk: %s failed to %s\n", c->res_name,
             enable ? "enable" : "disable");
        return ret;
}

static int clk_rpmh_prepare(struct clk_hw *hw)
{
        struct clk_rpmh *c = to_clk_rpmh(hw);
        int ret = 0;

        mutex_lock(&rpmh_clk_lock);
        ret = clk_rpmh_aggregate_state_send_command(c, true);
        mutex_unlock(&rpmh_clk_lock);

        return ret;
};

static void clk_rpmh_unprepare(struct clk_hw *hw)
{
        struct clk_rpmh *c = to_clk_rpmh(hw);

        mutex_lock(&rpmh_clk_lock);
        clk_rpmh_aggregate_state_send_command(c, false);
        mutex_unlock(&rpmh_clk_lock);
};

static unsigned long clk_rpmh_recalc_rate(struct clk_hw *hw,
                                        unsigned long prate)
{
        struct clk_rpmh *r = to_clk_rpmh(hw);

        /*
         * RPMh clocks have a fixed rate. Return static rate.
         */
        return prate / r->div;
}

static const struct clk_ops clk_rpmh_ops = {
        .prepare        = clk_rpmh_prepare,
        .unprepare      = clk_rpmh_unprepare,
        .recalc_rate    = clk_rpmh_recalc_rate,
};

static int clk_rpmh_bcm_send_cmd(struct clk_rpmh *c, bool enable)
{
        struct tcs_cmd cmd = { 0 };
        u32 cmd_state;
        int ret;

        mutex_lock(&rpmh_clk_lock);

        cmd_state = 0;
        if (enable) {
                cmd_state = 1;
                if (c->aggr_state)
                        cmd_state = c->aggr_state;
        }

        if (c->last_sent_aggr_state == cmd_state) {
                mutex_unlock(&rpmh_clk_lock);
                return 0;
        }

        cmd.addr = c->res_addr;
        cmd.data = BCM_TCS_CMD(enable, cmd_state);

        ret = rpmh_write_async(c->dev, RPMH_ACTIVE_ONLY_STATE, &cmd, 1);
        if (ret) {
                dev_err(c->dev, "set active state of %s failed: (%d)\n",
                        c->res_name, ret);
                mutex_unlock(&rpmh_clk_lock);
                return ret;
        }

        c->last_sent_aggr_state = cmd_state;

        mutex_unlock(&rpmh_clk_lock);

        return 0;
}

static int clk_rpmh_bcm_prepare(struct clk_hw *hw)
{
        struct clk_rpmh *c = to_clk_rpmh(hw);

        return clk_rpmh_bcm_send_cmd(c, true);
};

static void clk_rpmh_bcm_unprepare(struct clk_hw *hw)
{
        struct clk_rpmh *c = to_clk_rpmh(hw);

        clk_rpmh_bcm_send_cmd(c, false);
};

static int clk_rpmh_bcm_set_rate(struct clk_hw *hw, unsigned long rate,
                                 unsigned long parent_rate)
{
        struct clk_rpmh *c = to_clk_rpmh(hw);

        c->aggr_state = rate / c->unit;
        /*
         * Since any non-zero value sent to hw would result in enabling the
         * clock, only send the value if the clock has already been prepared.
         */
        if (clk_hw_is_prepared(hw))
                clk_rpmh_bcm_send_cmd(c, true);

        return 0;
};

static long clk_rpmh_round_rate(struct clk_hw *hw, unsigned long rate,
                                unsigned long *parent_rate)
{
        return rate;
}

static unsigned long clk_rpmh_bcm_recalc_rate(struct clk_hw *hw,
                                        unsigned long prate)
{
        struct clk_rpmh *c = to_clk_rpmh(hw);

        return c->aggr_state * c->unit;
}

static const struct clk_ops clk_rpmh_bcm_ops = {
        .prepare        = clk_rpmh_bcm_prepare,
        .unprepare      = clk_rpmh_bcm_unprepare,
        .set_rate       = clk_rpmh_bcm_set_rate,
        .round_rate     = clk_rpmh_round_rate,
        .recalc_rate    = clk_rpmh_bcm_recalc_rate,
};

/* Resource name must match resource id present in cmd-db. */
DEFINE_CLK_RPMH_ARC(sdm845, bi_tcxo, bi_tcxo_ao, "xo.lvl", 0x3, 2);
DEFINE_CLK_RPMH_VRM(sdm845, ln_bb_clk2, ln_bb_clk2_ao, "lnbclka2", 2);
DEFINE_CLK_RPMH_VRM(sdm845, ln_bb_clk3, ln_bb_clk3_ao, "lnbclka3", 2);
DEFINE_CLK_RPMH_VRM(sdm845, rf_clk1, rf_clk1_ao, "rfclka1", 1);
DEFINE_CLK_RPMH_VRM(sdm845, rf_clk2, rf_clk2_ao, "rfclka2", 1);
DEFINE_CLK_RPMH_VRM(sdm845, rf_clk3, rf_clk3_ao, "rfclka3", 1);
DEFINE_CLK_RPMH_BCM(sdm845, ipa, "IP0");

static struct clk_hw *sdm845_rpmh_clocks[] = {
        [RPMH_CXO_CLK]          = &sdm845_bi_tcxo.hw,
        [RPMH_CXO_CLK_A]        = &sdm845_bi_tcxo_ao.hw,
        [RPMH_LN_BB_CLK2]       = &sdm845_ln_bb_clk2.hw,
        [RPMH_LN_BB_CLK2_A]     = &sdm845_ln_bb_clk2_ao.hw,
        [RPMH_LN_BB_CLK3]       = &sdm845_ln_bb_clk3.hw,
        [RPMH_LN_BB_CLK3_A]     = &sdm845_ln_bb_clk3_ao.hw,
        [RPMH_RF_CLK1]          = &sdm845_rf_clk1.hw,
        [RPMH_RF_CLK1_A]        = &sdm845_rf_clk1_ao.hw,
        [RPMH_RF_CLK2]          = &sdm845_rf_clk2.hw,
        [RPMH_RF_CLK2_A]        = &sdm845_rf_clk2_ao.hw,
        [RPMH_RF_CLK3]          = &sdm845_rf_clk3.hw,
        [RPMH_RF_CLK3_A]        = &sdm845_rf_clk3_ao.hw,
        [RPMH_IPA_CLK]          = &sdm845_ipa.hw,
};

static const struct clk_rpmh_desc clk_rpmh_sdm845 = {
        .clks = sdm845_rpmh_clocks,
        .num_clks = ARRAY_SIZE(sdm845_rpmh_clocks),
};

static struct clk_hw *of_clk_rpmh_hw_get(struct of_phandle_args *clkspec,
                                         void *data)
{
        struct clk_rpmh_desc *rpmh = data;
        unsigned int idx = clkspec->args[0];

        if (idx >= rpmh->num_clks) {
                pr_err("%s: invalid index %u\n", __func__, idx);
                return ERR_PTR(-EINVAL);
        }

        return rpmh->clks[idx];
}

static int clk_rpmh_probe(struct platform_device *pdev)
{
        struct clk_hw **hw_clks;
        struct clk_rpmh *rpmh_clk;
        const struct clk_rpmh_desc *desc;
        int ret, i;

        desc = of_device_get_match_data(&pdev->dev);
        if (!desc)
                return -ENODEV;

        hw_clks = desc->clks;

        for (i = 0; i < desc->num_clks; i++) {
                u32 res_addr;
                size_t aux_data_len;
                const struct bcm_db *data;

                rpmh_clk = to_clk_rpmh(hw_clks[i]);
                res_addr = cmd_db_read_addr(rpmh_clk->res_name);
                if (!res_addr) {
                        dev_err(&pdev->dev, "missing RPMh resource address for %s\n",
                                rpmh_clk->res_name);
                        return -ENODEV;
                }

                data = cmd_db_read_aux_data(rpmh_clk->res_name, &aux_data_len);
                if (IS_ERR(data)) {
                        ret = PTR_ERR(data);
                        dev_err(&pdev->dev,
                                "error reading RPMh aux data for %s (%d)\n",
                                rpmh_clk->res_name, ret);
                        return ret;
                }

                /* Convert unit from Khz to Hz */
                if (aux_data_len == sizeof(*data))
                        rpmh_clk->unit = le32_to_cpu(data->unit) * 1000ULL;

                rpmh_clk->res_addr += res_addr;
                rpmh_clk->dev = &pdev->dev;

                ret = devm_clk_hw_register(&pdev->dev, hw_clks[i]);
                if (ret) {
                        dev_err(&pdev->dev, "failed to register %s\n",
                                hw_clks[i]->init->name);
                        return ret;
                }
        }

        /* typecast to silence compiler warning */
        ret = devm_of_clk_add_hw_provider(&pdev->dev, of_clk_rpmh_hw_get,
                                          (void *)desc);
        if (ret) {
                dev_err(&pdev->dev, "Failed to add clock provider\n");
                return ret;
        }

        dev_dbg(&pdev->dev, "Registered RPMh clocks\n");

        return 0;
}

static const struct of_device_id clk_rpmh_match_table[] = {
        { .compatible = "qcom,sdm845-rpmh-clk", .data = &clk_rpmh_sdm845},
        { }
};
MODULE_DEVICE_TABLE(of, clk_rpmh_match_table);

static struct platform_driver clk_rpmh_driver = {
        .probe          = clk_rpmh_probe,
        .driver         = {
                .name   = "clk-rpmh",
                .of_match_table = clk_rpmh_match_table,
        },
};

static int __init clk_rpmh_init(void)
{
        return platform_driver_register(&clk_rpmh_driver);
}
subsys_initcall(clk_rpmh_init);

static void __exit clk_rpmh_exit(void)
{
        platform_driver_unregister(&clk_rpmh_driver);
}
module_exit(clk_rpmh_exit);

MODULE_DESCRIPTION("QCOM RPMh Clock Driver");
MODULE_LICENSE("GPL v2");