root/drivers/spi/spi-rpc-if.c
// SPDX-License-Identifier: GPL-2.0
//
// RPC-IF SPI/QSPI/Octa driver
//
// Copyright (C) 2018 ~ 2019 Renesas Solutions Corp.
// Copyright (C) 2019 Macronix International Co., Ltd.
// Copyright (C) 2019 - 2020 Cogent Embedded, Inc.
//

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi-mem.h>

#include <memory/renesas-rpc-if.h>

#include <linux/unaligned.h>

static void rpcif_spi_mem_prepare(struct spi_device *spi_dev,
                                  const struct spi_mem_op *spi_op,
                                  u64 *offs, size_t *len)
{
        struct rpcif *rpc = spi_controller_get_devdata(spi_dev->controller);
        struct rpcif_op rpc_op = { };

        rpc_op.cmd.opcode = spi_op->cmd.opcode;
        rpc_op.cmd.buswidth = spi_op->cmd.buswidth;

        if (spi_op->addr.nbytes) {
                rpc_op.addr.buswidth = spi_op->addr.buswidth;
                rpc_op.addr.nbytes = spi_op->addr.nbytes;
                rpc_op.addr.val = spi_op->addr.val;
        }

        if (spi_op->dummy.nbytes) {
                rpc_op.dummy.buswidth = spi_op->dummy.buswidth;
                rpc_op.dummy.ncycles  = spi_op->dummy.nbytes * 8 /
                                        spi_op->dummy.buswidth;
        }

        if (spi_op->data.nbytes || (offs && len)) {
                rpc_op.data.buswidth = spi_op->data.buswidth;
                rpc_op.data.nbytes = spi_op->data.nbytes;
                switch (spi_op->data.dir) {
                case SPI_MEM_DATA_IN:
                        rpc_op.data.dir = RPCIF_DATA_IN;
                        rpc_op.data.buf.in = spi_op->data.buf.in;
                        break;
                case SPI_MEM_DATA_OUT:
                        rpc_op.data.dir = RPCIF_DATA_OUT;
                        rpc_op.data.buf.out = spi_op->data.buf.out;
                        break;
                case SPI_MEM_NO_DATA:
                        rpc_op.data.dir = RPCIF_NO_DATA;
                        break;
                }
        } else  {
                rpc_op.data.dir = RPCIF_NO_DATA;
        }

        rpcif_prepare(rpc->dev, &rpc_op, offs, len);
}

static bool rpcif_spi_mem_supports_op(struct spi_mem *mem,
                                      const struct spi_mem_op *op)
{
        if (!spi_mem_default_supports_op(mem, op))
                return false;

        if (op->data.buswidth > 4 || op->addr.buswidth > 4 ||
            op->dummy.buswidth > 4 || op->cmd.buswidth > 4 ||
            op->addr.nbytes > 4)
                return false;

        return true;
}

static ssize_t xspi_spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
                                         u64 offs, size_t len, const void *buf)
{
        struct rpcif *rpc = spi_controller_get_devdata(desc->mem->spi->controller);

        if (offs + desc->info.offset + len > U32_MAX)
                return -EINVAL;

        rpcif_spi_mem_prepare(desc->mem->spi, &desc->info.op_tmpl, &offs, &len);

        return xspi_dirmap_write(rpc->dev, offs, len, buf);
}

static ssize_t rpcif_spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
                                         u64 offs, size_t len, void *buf)
{
        struct rpcif *rpc =
                spi_controller_get_devdata(desc->mem->spi->controller);

        if (offs + desc->info.offset + len > U32_MAX)
                return -EINVAL;

        rpcif_spi_mem_prepare(desc->mem->spi, &desc->info.op_tmpl, &offs, &len);

        return rpcif_dirmap_read(rpc->dev, offs, len, buf);
}

static int rpcif_spi_mem_dirmap_create(struct spi_mem_dirmap_desc *desc)
{
        struct rpcif *rpc =
                spi_controller_get_devdata(desc->mem->spi->controller);

        if (desc->info.offset + desc->info.length > U32_MAX)
                return -EINVAL;

        if (!rpcif_spi_mem_supports_op(desc->mem, &desc->info.op_tmpl))
                return -EOPNOTSUPP;

        if (!rpc->dirmap)
                return -EOPNOTSUPP;

        if (!rpc->xspi && desc->info.op_tmpl.data.dir != SPI_MEM_DATA_IN)
                return -EOPNOTSUPP;

        return 0;
}

static int rpcif_spi_mem_exec_op(struct spi_mem *mem,
                                 const struct spi_mem_op *op)
{
        struct rpcif *rpc =
                spi_controller_get_devdata(mem->spi->controller);

        rpcif_spi_mem_prepare(mem->spi, op, NULL, NULL);

        return rpcif_manual_xfer(rpc->dev);
}

static const struct spi_controller_mem_ops rpcif_spi_mem_ops = {
        .supports_op    = rpcif_spi_mem_supports_op,
        .exec_op        = rpcif_spi_mem_exec_op,
        .dirmap_create  = rpcif_spi_mem_dirmap_create,
        .dirmap_read    = rpcif_spi_mem_dirmap_read,
        .dirmap_write   = xspi_spi_mem_dirmap_write,
};

static int rpcif_spi_probe(struct platform_device *pdev)
{
        struct device *parent = pdev->dev.parent;
        struct spi_controller *ctlr;
        struct rpcif *rpc;
        int error;

        ctlr = devm_spi_alloc_host(&pdev->dev, sizeof(*rpc));
        if (!ctlr)
                return -ENOMEM;

        rpc = spi_controller_get_devdata(ctlr);
        error = rpcif_sw_init(rpc, parent);
        if (error)
                return error;

        platform_set_drvdata(pdev, ctlr);

        ctlr->dev.of_node = parent->of_node;

        pm_runtime_enable(rpc->dev);

        ctlr->num_chipselect = 1;
        ctlr->mem_ops = &rpcif_spi_mem_ops;

        ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
        ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_TX_QUAD | SPI_RX_QUAD;
        ctlr->flags = SPI_CONTROLLER_HALF_DUPLEX;

        error = rpcif_hw_init(rpc->dev, false);
        if (error)
                goto out_disable_rpm;

        error = spi_register_controller(ctlr);
        if (error) {
                dev_err(&pdev->dev, "spi_register_controller failed\n");
                goto out_disable_rpm;
        }

        return 0;

out_disable_rpm:
        pm_runtime_disable(rpc->dev);
        return error;
}

static void rpcif_spi_remove(struct platform_device *pdev)
{
        struct spi_controller *ctlr = platform_get_drvdata(pdev);
        struct rpcif *rpc = spi_controller_get_devdata(ctlr);

        spi_unregister_controller(ctlr);
        pm_runtime_disable(rpc->dev);
}

static int rpcif_spi_suspend(struct device *dev)
{
        struct spi_controller *ctlr = dev_get_drvdata(dev);

        return spi_controller_suspend(ctlr);
}

static int rpcif_spi_resume(struct device *dev)
{
        struct spi_controller *ctlr = dev_get_drvdata(dev);

        rpcif_hw_init(dev, false);

        return spi_controller_resume(ctlr);
}

static DEFINE_SIMPLE_DEV_PM_OPS(rpcif_spi_pm_ops, rpcif_spi_suspend, rpcif_spi_resume);

static const struct platform_device_id rpc_if_spi_id_table[] = {
        { .name = "rpc-if-spi" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, rpc_if_spi_id_table);

static struct platform_driver rpcif_spi_driver = {
        .probe  = rpcif_spi_probe,
        .remove = rpcif_spi_remove,
        .id_table = rpc_if_spi_id_table,
        .driver = {
                .name   = "rpc-if-spi",
                .pm     = pm_sleep_ptr(&rpcif_spi_pm_ops),
        },
};
module_platform_driver(rpcif_spi_driver);

MODULE_DESCRIPTION("Renesas RPC-IF SPI driver");
MODULE_LICENSE("GPL v2");