root/drivers/remoteproc/st_remoteproc.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * ST's Remote Processor Control Driver
 *
 * Copyright (C) 2015 STMicroelectronics - All Rights Reserved
 *
 * Author: Ludovic Barre <ludovic.barre@st.com>
 */

#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mailbox_client.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/remoteproc.h>
#include <linux/reset.h>

#include "remoteproc_internal.h"

#define ST_RPROC_VQ0            0
#define ST_RPROC_VQ1            1
#define ST_RPROC_MAX_VRING      2

#define MBOX_RX                 0
#define MBOX_TX                 1
#define MBOX_MAX                2

struct st_rproc_config {
        bool                    sw_reset;
        bool                    pwr_reset;
        unsigned long           bootaddr_mask;
};

struct st_rproc {
        struct st_rproc_config  *config;
        struct reset_control    *sw_reset;
        struct reset_control    *pwr_reset;
        struct clk              *clk;
        u32                     clk_rate;
        struct regmap           *boot_base;
        u32                     boot_offset;
        struct mbox_chan        *mbox_chan[ST_RPROC_MAX_VRING * MBOX_MAX];
        struct mbox_client mbox_client_vq0;
        struct mbox_client mbox_client_vq1;
};

static void st_rproc_mbox_callback(struct device *dev, u32 msg)
{
        struct rproc *rproc = dev_get_drvdata(dev);

        if (rproc_vq_interrupt(rproc, msg) == IRQ_NONE)
                dev_dbg(dev, "no message was found in vqid %d\n", msg);
}

static
void st_rproc_mbox_callback_vq0(struct mbox_client *mbox_client, void *data)
{
        st_rproc_mbox_callback(mbox_client->dev, 0);
}

static
void st_rproc_mbox_callback_vq1(struct mbox_client *mbox_client, void *data)
{
        st_rproc_mbox_callback(mbox_client->dev, 1);
}

static void st_rproc_kick(struct rproc *rproc, int vqid)
{
        struct st_rproc *ddata = rproc->priv;
        struct device *dev = rproc->dev.parent;
        int ret;

        /* send the index of the triggered virtqueue in the mailbox payload */
        if (WARN_ON(vqid >= ST_RPROC_MAX_VRING))
                return;

        ret = mbox_send_message(ddata->mbox_chan[vqid * MBOX_MAX + MBOX_TX],
                                (void *)&vqid);
        if (ret < 0)
                dev_err(dev, "failed to send message via mbox: %d\n", ret);
}

static int st_rproc_mem_alloc(struct rproc *rproc,
                              struct rproc_mem_entry *mem)
{
        struct device *dev = rproc->dev.parent;
        void *va;

        va = ioremap_wc(mem->dma, mem->len);
        if (!va) {
                dev_err(dev, "Unable to map memory region: %pa+%zx\n",
                        &mem->dma, mem->len);
                return -ENOMEM;
        }

        /* Update memory entry va */
        mem->va = va;

        return 0;
}

static int st_rproc_mem_release(struct rproc *rproc,
                                struct rproc_mem_entry *mem)
{
        iounmap(mem->va);

        return 0;
}

static int st_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
{
        struct device *dev = rproc->dev.parent;
        struct device_node *np = dev->of_node;
        struct rproc_mem_entry *mem;
        int entries;

        entries = of_reserved_mem_region_count(np);

        for (int index = 0; index < entries; index++) {
                struct resource res;
                int ret;

                ret = of_reserved_mem_region_to_resource(np, index, &res);
                if (ret)
                        return ret;

                /*  No need to map vdev buffer */
                if (!strstarts(res.name, "vdev0buffer")) {
                        /* Register memory region */
                        mem = rproc_mem_entry_init(dev, NULL,
                                                   (dma_addr_t)res.start,
                                                   resource_size(&res), res.start,
                                                   st_rproc_mem_alloc,
                                                   st_rproc_mem_release,
                                                   "%.*s",
                                                   strchrnul(res.name, '@') - res.name,
                                                   res.name);
                } else {
                        /* Register reserved memory for vdev buffer allocation */
                        mem = rproc_of_resm_mem_entry_init(dev, index,
                                                           resource_size(&res),
                                                           res.start,
                                                           "vdev0buffer");
                }

                if (!mem)
                        return -ENOMEM;

                rproc_add_carveout(rproc, mem);
        }

        return rproc_elf_load_rsc_table(rproc, fw);
}

static int st_rproc_start(struct rproc *rproc)
{
        struct st_rproc *ddata = rproc->priv;
        int err;

        regmap_update_bits(ddata->boot_base, ddata->boot_offset,
                           ddata->config->bootaddr_mask, rproc->bootaddr);

        err = clk_enable(ddata->clk);
        if (err) {
                dev_err(&rproc->dev, "Failed to enable clock\n");
                return err;
        }

        if (ddata->config->sw_reset) {
                err = reset_control_deassert(ddata->sw_reset);
                if (err) {
                        dev_err(&rproc->dev, "Failed to deassert S/W Reset\n");
                        goto sw_reset_fail;
                }
        }

        if (ddata->config->pwr_reset) {
                err = reset_control_deassert(ddata->pwr_reset);
                if (err) {
                        dev_err(&rproc->dev, "Failed to deassert Power Reset\n");
                        goto pwr_reset_fail;
                }
        }

        dev_info(&rproc->dev, "Started from 0x%llx\n", rproc->bootaddr);

        return 0;


pwr_reset_fail:
        if (ddata->config->pwr_reset)
                reset_control_assert(ddata->sw_reset);
sw_reset_fail:
        clk_disable(ddata->clk);

        return err;
}

static int st_rproc_stop(struct rproc *rproc)
{
        struct st_rproc *ddata = rproc->priv;
        int sw_err = 0, pwr_err = 0;

        if (ddata->config->sw_reset) {
                sw_err = reset_control_assert(ddata->sw_reset);
                if (sw_err)
                        dev_err(&rproc->dev, "Failed to assert S/W Reset\n");
        }

        if (ddata->config->pwr_reset) {
                pwr_err = reset_control_assert(ddata->pwr_reset);
                if (pwr_err)
                        dev_err(&rproc->dev, "Failed to assert Power Reset\n");
        }

        clk_disable(ddata->clk);

        return sw_err ?: pwr_err;
}

static const struct rproc_ops st_rproc_ops = {
        .kick                   = st_rproc_kick,
        .start                  = st_rproc_start,
        .stop                   = st_rproc_stop,
        .parse_fw               = st_rproc_parse_fw,
        .load                   = rproc_elf_load_segments,
        .find_loaded_rsc_table  = rproc_elf_find_loaded_rsc_table,
        .sanity_check           = rproc_elf_sanity_check,
        .get_boot_addr          = rproc_elf_get_boot_addr,
};

/*
 * Fetch state of the processor: 0 is off, 1 is on.
 */
static int st_rproc_state(struct platform_device *pdev)
{
        struct rproc *rproc = platform_get_drvdata(pdev);
        struct st_rproc *ddata = rproc->priv;
        int reset_sw = 0, reset_pwr = 0;

        if (ddata->config->sw_reset)
                reset_sw = reset_control_status(ddata->sw_reset);

        if (ddata->config->pwr_reset)
                reset_pwr = reset_control_status(ddata->pwr_reset);

        if (reset_sw < 0 || reset_pwr < 0)
                return -EINVAL;

        return !reset_sw && !reset_pwr;
}

static const struct st_rproc_config st40_rproc_cfg = {
        .sw_reset = true,
        .pwr_reset = true,
        .bootaddr_mask = GENMASK(28, 1),
};

static const struct st_rproc_config st231_rproc_cfg = {
        .sw_reset = true,
        .pwr_reset = false,
        .bootaddr_mask = GENMASK(31, 6),
};

static const struct of_device_id st_rproc_match[] = {
        { .compatible = "st,st40-rproc", .data = &st40_rproc_cfg },
        { .compatible = "st,st231-rproc", .data = &st231_rproc_cfg },
        {},
};
MODULE_DEVICE_TABLE(of, st_rproc_match);

static int st_rproc_parse_dt(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct rproc *rproc = platform_get_drvdata(pdev);
        struct st_rproc *ddata = rproc->priv;
        struct device_node *np = dev->of_node;
        int err;

        if (ddata->config->sw_reset) {
                ddata->sw_reset = devm_reset_control_get_exclusive(dev,
                                                                   "sw_reset");
                if (IS_ERR(ddata->sw_reset))
                        return dev_err_probe(dev, PTR_ERR(ddata->sw_reset),
                                             "Failed to get S/W Reset\n");
        }

        if (ddata->config->pwr_reset) {
                ddata->pwr_reset = devm_reset_control_get_exclusive(dev,
                                                                    "pwr_reset");
                if (IS_ERR(ddata->pwr_reset))
                        return dev_err_probe(dev, PTR_ERR(ddata->pwr_reset),
                                             "Failed to get Power Reset\n");
        }

        ddata->clk = devm_clk_get(dev, NULL);
        if (IS_ERR(ddata->clk))
                return dev_err_probe(dev, PTR_ERR(ddata->clk),
                                     "Failed to get clock\n");

        err = of_property_read_u32(np, "clock-frequency", &ddata->clk_rate);
        if (err) {
                dev_err(dev, "failed to get clock frequency\n");
                return err;
        }

        ddata->boot_base = syscon_regmap_lookup_by_phandle_args(np, "st,syscfg",
                                                                1, &ddata->boot_offset);
        if (IS_ERR(ddata->boot_base))
                return dev_err_probe(dev, PTR_ERR(ddata->boot_base),
                                     "Boot base not found\n");

        err = clk_prepare(ddata->clk);
        if (err)
                dev_err(dev, "failed to get clock\n");

        return err;
}

static int st_rproc_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct st_rproc *ddata;
        struct device_node *np = dev->of_node;
        struct rproc *rproc;
        struct mbox_chan *chan;
        int enabled;
        int ret, i;

        rproc = devm_rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
        if (!rproc)
                return -ENOMEM;

        rproc->has_iommu = false;
        ddata = rproc->priv;
        ddata->config = (struct st_rproc_config *)device_get_match_data(dev);
        if (!ddata->config)
                return -ENODEV;

        platform_set_drvdata(pdev, rproc);

        ret = st_rproc_parse_dt(pdev);
        if (ret)
                return ret;

        enabled = st_rproc_state(pdev);
        if (enabled < 0) {
                ret = enabled;
                goto free_clk;
        }

        if (enabled) {
                atomic_inc(&rproc->power);
                rproc->state = RPROC_RUNNING;
        } else {
                clk_set_rate(ddata->clk, ddata->clk_rate);
        }

        if (of_property_present(np, "mbox-names")) {
                ddata->mbox_client_vq0.dev              = dev;
                ddata->mbox_client_vq0.tx_done          = NULL;
                ddata->mbox_client_vq0.tx_block = false;
                ddata->mbox_client_vq0.knows_txdone     = false;
                ddata->mbox_client_vq0.rx_callback      = st_rproc_mbox_callback_vq0;

                ddata->mbox_client_vq1.dev              = dev;
                ddata->mbox_client_vq1.tx_done          = NULL;
                ddata->mbox_client_vq1.tx_block = false;
                ddata->mbox_client_vq1.knows_txdone     = false;
                ddata->mbox_client_vq1.rx_callback      = st_rproc_mbox_callback_vq1;

                /*
                 * To control a co-processor without IPC mechanism.
                 * This driver can be used without mbox and rpmsg.
                 */
                chan = mbox_request_channel_byname(&ddata->mbox_client_vq0, "vq0_rx");
                if (IS_ERR(chan)) {
                        ret = dev_err_probe(&rproc->dev, PTR_ERR(chan),
                                            "failed to request mbox chan 0\n");
                        goto free_clk;
                }
                ddata->mbox_chan[ST_RPROC_VQ0 * MBOX_MAX + MBOX_RX] = chan;

                chan = mbox_request_channel_byname(&ddata->mbox_client_vq0, "vq0_tx");
                if (IS_ERR(chan)) {
                        ret = dev_err_probe(&rproc->dev, PTR_ERR(chan),
                                            "failed to request mbox chan 0\n");
                        goto free_mbox;
                }
                ddata->mbox_chan[ST_RPROC_VQ0 * MBOX_MAX + MBOX_TX] = chan;

                chan = mbox_request_channel_byname(&ddata->mbox_client_vq1, "vq1_rx");
                if (IS_ERR(chan)) {
                        ret = dev_err_probe(&rproc->dev, PTR_ERR(chan),
                                            "failed to request mbox chan 1\n");
                        goto free_mbox;
                }
                ddata->mbox_chan[ST_RPROC_VQ1 * MBOX_MAX + MBOX_RX] = chan;

                chan = mbox_request_channel_byname(&ddata->mbox_client_vq1, "vq1_tx");
                if (IS_ERR(chan)) {
                        ret = dev_err_probe(&rproc->dev, PTR_ERR(chan),
                                            "failed to request mbox chan 1\n");
                        goto free_mbox;
                }
                ddata->mbox_chan[ST_RPROC_VQ1 * MBOX_MAX + MBOX_TX] = chan;
        }

        ret = rproc_add(rproc);
        if (ret)
                goto free_mbox;

        return 0;

free_mbox:
        for (i = 0; i < ST_RPROC_MAX_VRING * MBOX_MAX; i++)
                mbox_free_channel(ddata->mbox_chan[i]);
free_clk:
        clk_unprepare(ddata->clk);

        return ret;
}

static void st_rproc_remove(struct platform_device *pdev)
{
        struct rproc *rproc = platform_get_drvdata(pdev);
        struct st_rproc *ddata = rproc->priv;
        int i;

        rproc_del(rproc);

        clk_disable_unprepare(ddata->clk);

        for (i = 0; i < ST_RPROC_MAX_VRING * MBOX_MAX; i++)
                mbox_free_channel(ddata->mbox_chan[i]);
}

static struct platform_driver st_rproc_driver = {
        .probe = st_rproc_probe,
        .remove = st_rproc_remove,
        .driver = {
                .name = "st-rproc",
                .of_match_table = of_match_ptr(st_rproc_match),
        },
};
module_platform_driver(st_rproc_driver);

MODULE_DESCRIPTION("ST Remote Processor Control Driver");
MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
MODULE_LICENSE("GPL v2");