// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * SLIM core rproc driver
 *
 * Copyright (C) 2016 STMicroelectronics
 *
 * Author: Peter Griffin <peter.griffin@linaro.org>
 */

#include <linux/clk.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/remoteproc.h>
#include <linux/remoteproc/st_slim_rproc.h>
#include "remoteproc_internal.h"

/* SLIM core registers */
#define SLIM_ID_OFST            0x0
#define SLIM_VER_OFST           0x4

#define SLIM_EN_OFST            0x8
#define SLIM_EN_RUN                     BIT(0)

#define SLIM_CLK_GATE_OFST      0xC
#define SLIM_CLK_GATE_DIS               BIT(0)
#define SLIM_CLK_GATE_RESET             BIT(2)

#define SLIM_SLIM_PC_OFST       0x20

/* DMEM registers */
#define SLIM_REV_ID_OFST        0x0
#define SLIM_REV_ID_MIN_MASK            GENMASK(15, 8)
#define SLIM_REV_ID_MIN(id)             ((id & SLIM_REV_ID_MIN_MASK) >> 8)
#define SLIM_REV_ID_MAJ_MASK            GENMASK(23, 16)
#define SLIM_REV_ID_MAJ(id)             ((id & SLIM_REV_ID_MAJ_MASK) >> 16)


/* peripherals registers */
#define SLIM_STBUS_SYNC_OFST    0xF88
#define SLIM_STBUS_SYNC_DIS             BIT(0)

#define SLIM_INT_SET_OFST       0xFD4
#define SLIM_INT_CLR_OFST       0xFD8
#define SLIM_INT_MASK_OFST      0xFDC

#define SLIM_CMD_CLR_OFST       0xFC8
#define SLIM_CMD_MASK_OFST      0xFCC

static const char *mem_names[ST_SLIM_MEM_MAX] = {
        [ST_SLIM_DMEM]  = "dmem",
        [ST_SLIM_IMEM]  = "imem",
};

static int slim_clk_get(struct st_slim_rproc *slim_rproc, struct device *dev)
{
        int clk, err;

        for (clk = 0; clk < ST_SLIM_MAX_CLK; clk++) {
                slim_rproc->clks[clk] = of_clk_get(dev->of_node, clk);
                if (IS_ERR(slim_rproc->clks[clk])) {
                        err = PTR_ERR(slim_rproc->clks[clk]);
                        if (err == -EPROBE_DEFER)
                                goto err_put_clks;
                        slim_rproc->clks[clk] = NULL;
                        break;
                }
        }

        return 0;

err_put_clks:
        while (--clk >= 0)
                clk_put(slim_rproc->clks[clk]);

        return err;
}

static void slim_clk_disable(struct st_slim_rproc *slim_rproc)
{
        int clk;

        for (clk = 0; clk < ST_SLIM_MAX_CLK && slim_rproc->clks[clk]; clk++)
                clk_disable_unprepare(slim_rproc->clks[clk]);
}

static int slim_clk_enable(struct st_slim_rproc *slim_rproc)
{
        int clk, ret;

        for (clk = 0; clk < ST_SLIM_MAX_CLK && slim_rproc->clks[clk]; clk++) {
                ret = clk_prepare_enable(slim_rproc->clks[clk]);
                if (ret)
                        goto err_disable_clks;
        }

        return 0;

err_disable_clks:
        while (--clk >= 0)
                clk_disable_unprepare(slim_rproc->clks[clk]);

        return ret;
}

/*
 * Remoteproc slim specific device handlers
 */
static int slim_rproc_start(struct rproc *rproc)
{
        struct device *dev = &rproc->dev;
        struct st_slim_rproc *slim_rproc = rproc->priv;
        unsigned long hw_id, hw_ver, fw_rev;
        u32 val;

        /* disable CPU pipeline clock & reset CPU pipeline */
        val = SLIM_CLK_GATE_DIS | SLIM_CLK_GATE_RESET;
        writel(val, slim_rproc->slimcore + SLIM_CLK_GATE_OFST);

        /* disable SLIM core STBus sync */
        writel(SLIM_STBUS_SYNC_DIS, slim_rproc->peri + SLIM_STBUS_SYNC_OFST);

        /* enable cpu pipeline clock */
        writel(!SLIM_CLK_GATE_DIS,
                slim_rproc->slimcore + SLIM_CLK_GATE_OFST);

        /* clear int & cmd mailbox */
        writel(~0U, slim_rproc->peri + SLIM_INT_CLR_OFST);
        writel(~0U, slim_rproc->peri + SLIM_CMD_CLR_OFST);

        /* enable all channels cmd & int */
        writel(~0U, slim_rproc->peri + SLIM_INT_MASK_OFST);
        writel(~0U, slim_rproc->peri + SLIM_CMD_MASK_OFST);

        /* enable cpu */
        writel(SLIM_EN_RUN, slim_rproc->slimcore + SLIM_EN_OFST);

        hw_id = readl_relaxed(slim_rproc->slimcore + SLIM_ID_OFST);
        hw_ver = readl_relaxed(slim_rproc->slimcore + SLIM_VER_OFST);

        fw_rev = readl(slim_rproc->mem[ST_SLIM_DMEM].cpu_addr +
                        SLIM_REV_ID_OFST);

        dev_info(dev, "fw rev:%ld.%ld on SLIM %ld.%ld\n",
                 SLIM_REV_ID_MAJ(fw_rev), SLIM_REV_ID_MIN(fw_rev),
                 hw_id, hw_ver);

        return 0;
}

static int slim_rproc_stop(struct rproc *rproc)
{
        struct st_slim_rproc *slim_rproc = rproc->priv;
        u32 val;

        /* mask all (cmd & int) channels */
        writel(0UL, slim_rproc->peri + SLIM_INT_MASK_OFST);
        writel(0UL, slim_rproc->peri + SLIM_CMD_MASK_OFST);

        /* disable cpu pipeline clock */
        writel(SLIM_CLK_GATE_DIS, slim_rproc->slimcore + SLIM_CLK_GATE_OFST);

        writel(!SLIM_EN_RUN, slim_rproc->slimcore + SLIM_EN_OFST);

        val = readl(slim_rproc->slimcore + SLIM_EN_OFST);
        if (val & SLIM_EN_RUN)
                dev_warn(&rproc->dev, "Failed to disable SLIM");

        dev_dbg(&rproc->dev, "slim stopped\n");

        return 0;
}

static void *slim_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len, bool *is_iomem)
{
        struct st_slim_rproc *slim_rproc = rproc->priv;
        void *va = NULL;
        int i;

        for (i = 0; i < ST_SLIM_MEM_MAX; i++) {
                if (da != slim_rproc->mem[i].bus_addr)
                        continue;

                if (len <= slim_rproc->mem[i].size) {
                        /* __force to make sparse happy with type conversion */
                        va = (__force void *)slim_rproc->mem[i].cpu_addr;
                        break;
                }
        }

        dev_dbg(&rproc->dev, "da = 0x%llx len = 0x%zx va = 0x%p\n",
                da, len, va);

        return va;
}

static const struct rproc_ops slim_rproc_ops = {
        .start          = slim_rproc_start,
        .stop           = slim_rproc_stop,
        .da_to_va       = slim_rproc_da_to_va,
        .get_boot_addr  = rproc_elf_get_boot_addr,
        .load           = rproc_elf_load_segments,
        .sanity_check   = rproc_elf_sanity_check,
};

/**
 * st_slim_rproc_alloc() - allocate and initialise slim rproc
 * @pdev: Pointer to the platform_device struct
 * @fw_name: Name of firmware for rproc to use
 *
 * Function for allocating and initialising a slim rproc for use by
 * device drivers whose IP is based around the SLIM core. It
 * obtains and enables any clocks required by the SLIM core and also
 * ioremaps the various IO.
 *
 * Return: st_slim_rproc pointer or PTR_ERR() on error.
 */

struct st_slim_rproc *st_slim_rproc_alloc(struct platform_device *pdev,
                                char *fw_name)
{
        struct device *dev = &pdev->dev;
        struct st_slim_rproc *slim_rproc;
        struct device_node *np = dev->of_node;
        struct rproc *rproc;
        struct resource *res;
        int err, i;

        if (!fw_name)
                return ERR_PTR(-EINVAL);

        if (!of_device_is_compatible(np, "st,slim-rproc"))
                return ERR_PTR(-EINVAL);

        rproc = rproc_alloc(dev, np->name, &slim_rproc_ops,
                        fw_name, sizeof(*slim_rproc));
        if (!rproc)
                return ERR_PTR(-ENOMEM);

        rproc->has_iommu = false;

        slim_rproc = rproc->priv;
        slim_rproc->rproc = rproc;

        /* get imem and dmem */
        for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
                res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
                                                mem_names[i]);

                slim_rproc->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
                if (IS_ERR(slim_rproc->mem[i].cpu_addr)) {
                        dev_err(&pdev->dev, "devm_ioremap_resource failed\n");
                        err = PTR_ERR(slim_rproc->mem[i].cpu_addr);
                        goto err;
                }
                slim_rproc->mem[i].bus_addr = res->start;
                slim_rproc->mem[i].size = resource_size(res);
        }

        slim_rproc->slimcore = devm_platform_ioremap_resource_byname(pdev, "slimcore");
        if (IS_ERR(slim_rproc->slimcore)) {
                dev_err(&pdev->dev, "failed to ioremap slimcore IO\n");
                err = PTR_ERR(slim_rproc->slimcore);
                goto err;
        }

        slim_rproc->peri = devm_platform_ioremap_resource_byname(pdev, "peripherals");
        if (IS_ERR(slim_rproc->peri)) {
                dev_err(&pdev->dev, "failed to ioremap peripherals IO\n");
                err = PTR_ERR(slim_rproc->peri);
                goto err;
        }

        err = slim_clk_get(slim_rproc, dev);
        if (err)
                goto err;

        err = slim_clk_enable(slim_rproc);
        if (err) {
                dev_err(dev, "Failed to enable clocks\n");
                goto err_clk_put;
        }

        /* Register as a remoteproc device */
        err = rproc_add(rproc);
        if (err) {
                dev_err(dev, "registration of slim remoteproc failed\n");
                goto err_clk_dis;
        }

        return slim_rproc;

err_clk_dis:
        slim_clk_disable(slim_rproc);
err_clk_put:
        for (i = 0; i < ST_SLIM_MAX_CLK && slim_rproc->clks[i]; i++)
                clk_put(slim_rproc->clks[i]);
err:
        rproc_free(rproc);
        return ERR_PTR(err);
}
EXPORT_SYMBOL(st_slim_rproc_alloc);

/**
  * st_slim_rproc_put() - put slim rproc resources
  * @slim_rproc: Pointer to the st_slim_rproc struct
  *
  * Function for calling respective _put() functions on slim_rproc resources.
  *
  */
void st_slim_rproc_put(struct st_slim_rproc *slim_rproc)
{
        int clk;

        if (!slim_rproc)
                return;

        slim_clk_disable(slim_rproc);

        for (clk = 0; clk < ST_SLIM_MAX_CLK && slim_rproc->clks[clk]; clk++)
                clk_put(slim_rproc->clks[clk]);

        rproc_del(slim_rproc->rproc);
        rproc_free(slim_rproc->rproc);
}
EXPORT_SYMBOL(st_slim_rproc_put);

MODULE_AUTHOR("Peter Griffin <peter.griffin@linaro.org>");
MODULE_DESCRIPTION("STMicroelectronics SLIM core rproc driver");
MODULE_LICENSE("GPL v2");