root/drivers/clk/ti/clk-dra7-atl.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * DRA7 ATL (Audio Tracking Logic) clock driver
 *
 * Copyright (C) 2013 Texas Instruments, Inc.
 *
 * Peter Ujfalusi <peter.ujfalusi@ti.com>
 */

#include <linux/init.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/clk/ti.h>

#include "clock.h"

#define DRA7_ATL_INSTANCES      4

#define DRA7_ATL_PPMR_REG(id)           (0x200 + (id * 0x80))
#define DRA7_ATL_BBSR_REG(id)           (0x204 + (id * 0x80))
#define DRA7_ATL_ATLCR_REG(id)          (0x208 + (id * 0x80))
#define DRA7_ATL_SWEN_REG(id)           (0x210 + (id * 0x80))
#define DRA7_ATL_BWSMUX_REG(id)         (0x214 + (id * 0x80))
#define DRA7_ATL_AWSMUX_REG(id)         (0x218 + (id * 0x80))
#define DRA7_ATL_PCLKMUX_REG(id)        (0x21c + (id * 0x80))

#define DRA7_ATL_SWEN                   BIT(0)
#define DRA7_ATL_DIVIDER_MASK           (0x1f)
#define DRA7_ATL_PCLKMUX                BIT(0)
struct dra7_atl_clock_info;

struct dra7_atl_desc {
        struct clk *clk;
        struct clk_hw hw;
        struct dra7_atl_clock_info *cinfo;
        int id;

        bool probed;            /* the driver for the IP has been loaded */
        bool valid;             /* configured */
        bool enabled;
        u32 bws;                /* Baseband Word Select Mux */
        u32 aws;                /* Audio Word Select Mux */
        u32 divider;            /* Cached divider value */
};

struct dra7_atl_clock_info {
        struct device *dev;
        void __iomem *iobase;

        struct dra7_atl_desc *cdesc;
};

#define to_atl_desc(_hw)        container_of(_hw, struct dra7_atl_desc, hw)

static inline void atl_write(struct dra7_atl_clock_info *cinfo, u32 reg,
                             u32 val)
{
        __raw_writel(val, cinfo->iobase + reg);
}

static inline int atl_read(struct dra7_atl_clock_info *cinfo, u32 reg)
{
        return __raw_readl(cinfo->iobase + reg);
}

static int atl_clk_enable(struct clk_hw *hw)
{
        struct dra7_atl_desc *cdesc = to_atl_desc(hw);

        if (!cdesc->probed)
                goto out;

        if (unlikely(!cdesc->valid))
                dev_warn(cdesc->cinfo->dev, "atl%d has not been configured\n",
                         cdesc->id);
        pm_runtime_get_sync(cdesc->cinfo->dev);

        atl_write(cdesc->cinfo, DRA7_ATL_ATLCR_REG(cdesc->id),
                  cdesc->divider - 1);
        atl_write(cdesc->cinfo, DRA7_ATL_SWEN_REG(cdesc->id), DRA7_ATL_SWEN);

out:
        cdesc->enabled = true;

        return 0;
}

static void atl_clk_disable(struct clk_hw *hw)
{
        struct dra7_atl_desc *cdesc = to_atl_desc(hw);

        if (!cdesc->probed)
                goto out;

        atl_write(cdesc->cinfo, DRA7_ATL_SWEN_REG(cdesc->id), 0);
        pm_runtime_put_sync(cdesc->cinfo->dev);

out:
        cdesc->enabled = false;
}

static int atl_clk_is_enabled(struct clk_hw *hw)
{
        struct dra7_atl_desc *cdesc = to_atl_desc(hw);

        return cdesc->enabled;
}

static unsigned long atl_clk_recalc_rate(struct clk_hw *hw,
                                         unsigned long parent_rate)
{
        struct dra7_atl_desc *cdesc = to_atl_desc(hw);

        return parent_rate / cdesc->divider;
}

static int atl_clk_determine_rate(struct clk_hw *hw,
                                  struct clk_rate_request *req)
{
        unsigned divider;

        divider = (req->best_parent_rate + req->rate / 2) / req->rate;
        if (divider > DRA7_ATL_DIVIDER_MASK + 1)
                divider = DRA7_ATL_DIVIDER_MASK + 1;

        req->rate = req->best_parent_rate / divider;

        return 0;
}

static int atl_clk_set_rate(struct clk_hw *hw, unsigned long rate,
                            unsigned long parent_rate)
{
        struct dra7_atl_desc *cdesc;
        u32 divider;

        if (!hw || !rate)
                return -EINVAL;

        cdesc = to_atl_desc(hw);
        divider = ((parent_rate + rate / 2) / rate) - 1;
        if (divider > DRA7_ATL_DIVIDER_MASK)
                divider = DRA7_ATL_DIVIDER_MASK;

        cdesc->divider = divider + 1;

        return 0;
}

static const struct clk_ops atl_clk_ops = {
        .enable         = atl_clk_enable,
        .disable        = atl_clk_disable,
        .is_enabled     = atl_clk_is_enabled,
        .recalc_rate    = atl_clk_recalc_rate,
        .determine_rate = atl_clk_determine_rate,
        .set_rate       = atl_clk_set_rate,
};

static void __init of_dra7_atl_clock_setup(struct device_node *node)
{
        struct dra7_atl_desc *clk_hw = NULL;
        struct clk_parent_data pdata = { .index = 0 };
        struct clk_init_data init = { NULL };
        const char *name;
        struct clk *clk;

        clk_hw = kzalloc_obj(*clk_hw);
        if (!clk_hw) {
                pr_err("%s: could not allocate dra7_atl_desc\n", __func__);
                return;
        }

        clk_hw->hw.init = &init;
        clk_hw->divider = 1;
        name = ti_dt_clk_name(node);
        init.name = name;
        init.ops = &atl_clk_ops;
        init.flags = CLK_IGNORE_UNUSED;
        init.num_parents = of_clk_get_parent_count(node);

        if (init.num_parents != 1) {
                pr_err("%s: atl clock %pOFn must have 1 parent\n", __func__,
                       node);
                goto cleanup;
        }

        init.parent_data = &pdata;
        clk = of_ti_clk_register(node, &clk_hw->hw, name);

        if (!IS_ERR(clk)) {
                of_clk_add_provider(node, of_clk_src_simple_get, clk);
                return;
        }
cleanup:
        kfree(clk_hw);
}
CLK_OF_DECLARE(dra7_atl_clock, "ti,dra7-atl-clock", of_dra7_atl_clock_setup);

static int of_dra7_atl_clk_probe(struct platform_device *pdev)
{
        struct device_node *node = pdev->dev.of_node;
        struct dra7_atl_clock_info *cinfo;
        int i;
        int ret = 0;

        if (!node)
                return -ENODEV;

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

        cinfo->iobase = of_iomap(node, 0);
        cinfo->dev = &pdev->dev;
        pm_runtime_enable(cinfo->dev);

        pm_runtime_get_sync(cinfo->dev);
        atl_write(cinfo, DRA7_ATL_PCLKMUX_REG(0), DRA7_ATL_PCLKMUX);

        for (i = 0; i < DRA7_ATL_INSTANCES; i++) {
                struct device_node *cfg_node;
                char prop[5];
                struct dra7_atl_desc *cdesc;
                struct of_phandle_args clkspec;
                struct clk *clk;
                int rc;

                rc = of_parse_phandle_with_args(node, "ti,provided-clocks",
                                                NULL, i, &clkspec);

                if (rc) {
                        pr_err("%s: failed to lookup atl clock %d\n", __func__,
                               i);
                        ret = -EINVAL;
                        goto pm_put;
                }

                clk = of_clk_get_from_provider(&clkspec);
                of_node_put(clkspec.np);
                if (IS_ERR(clk)) {
                        pr_err("%s: failed to get atl clock %d from provider\n",
                               __func__, i);
                        ret = PTR_ERR(clk);
                        goto pm_put;
                }

                cdesc = to_atl_desc(__clk_get_hw(clk));
                cdesc->cinfo = cinfo;
                cdesc->id = i;

                /* Get configuration for the ATL instances */
                snprintf(prop, sizeof(prop), "atl%u", i);
                cfg_node = of_get_child_by_name(node, prop);
                if (cfg_node) {
                        ret = of_property_read_u32(cfg_node, "bws",
                                                   &cdesc->bws);
                        ret |= of_property_read_u32(cfg_node, "aws",
                                                    &cdesc->aws);
                        if (!ret) {
                                cdesc->valid = true;
                                atl_write(cinfo, DRA7_ATL_BWSMUX_REG(i),
                                          cdesc->bws);
                                atl_write(cinfo, DRA7_ATL_AWSMUX_REG(i),
                                          cdesc->aws);
                        }
                        of_node_put(cfg_node);
                }

                cdesc->probed = true;
                /*
                 * Enable the clock if it has been asked prior to loading the
                 * hw driver
                 */
                if (cdesc->enabled)
                        atl_clk_enable(__clk_get_hw(clk));
        }

pm_put:
        pm_runtime_put_sync(cinfo->dev);
        return ret;
}

static const struct of_device_id of_dra7_atl_clk_match_tbl[] = {
        { .compatible = "ti,dra7-atl", },
        {},
};

static struct platform_driver dra7_atl_clk_driver = {
        .driver = {
                .name = "dra7-atl",
                .suppress_bind_attrs = true,
                .of_match_table = of_dra7_atl_clk_match_tbl,
        },
        .probe = of_dra7_atl_clk_probe,
};
builtin_platform_driver(dra7_atl_clk_driver);