drivers/mtd/hyperbus/rpc-if.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Linux driver for RPC-IF HyperFlash
 *
 * Copyright (C) 2019-2020 Cogent Embedded, Inc.
 */

#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mtd/hyperbus.h>
#include <linux/mtd/mtd.h>
#include <linux/mux/consumer.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/types.h>

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

struct	rpcif_hyperbus {
	struct rpcif rpc;
	struct hyperbus_ctlr ctlr;
	struct hyperbus_device hbdev;
};

static const struct rpcif_op rpcif_op_tmpl = {
	.cmd = {
		.buswidth = 8,
		.ddr = true,
	},
	.ocmd = {
		.buswidth = 8,
		.ddr = true,
	},
	.addr = {
		.nbytes = 1,
		.buswidth = 8,
		.ddr = true,
	},
	.data = {
		.buswidth = 8,
		.ddr = true,
	},
};

static void rpcif_hb_prepare_read(struct rpcif *rpc, void *to,
				  unsigned long from, ssize_t len)
{
	struct rpcif_op op = rpcif_op_tmpl;

	op.cmd.opcode = HYPERBUS_RW_READ | HYPERBUS_AS_MEM;
	op.addr.val = from >> 1;
	op.dummy.buswidth = 1;
	op.dummy.ncycles = 15;
	op.data.dir = RPCIF_DATA_IN;
	op.data.nbytes = len;
	op.data.buf.in = to;

	rpcif_prepare(rpc, &op, NULL, NULL);
}

static void rpcif_hb_prepare_write(struct rpcif *rpc, unsigned long to,
				   void *from, ssize_t len)
{
	struct rpcif_op op = rpcif_op_tmpl;

	op.cmd.opcode = HYPERBUS_RW_WRITE | HYPERBUS_AS_MEM;
	op.addr.val = to >> 1;
	op.data.dir = RPCIF_DATA_OUT;
	op.data.nbytes = len;
	op.data.buf.out = from;

	rpcif_prepare(rpc, &op, NULL, NULL);
}

static u16 rpcif_hb_read16(struct hyperbus_device *hbdev, unsigned long addr)
{
	struct rpcif_hyperbus *hyperbus =
		container_of(hbdev, struct rpcif_hyperbus, hbdev);
	map_word data;

	rpcif_hb_prepare_read(&hyperbus->rpc, &data, addr, 2);

	rpcif_manual_xfer(&hyperbus->rpc);

	return data.x[0];
}

static void rpcif_hb_write16(struct hyperbus_device *hbdev, unsigned long addr,
			     u16 data)
{
	struct rpcif_hyperbus *hyperbus =
		container_of(hbdev, struct rpcif_hyperbus, hbdev);

	rpcif_hb_prepare_write(&hyperbus->rpc, addr, &data, 2);

	rpcif_manual_xfer(&hyperbus->rpc);
}

static void rpcif_hb_copy_from(struct hyperbus_device *hbdev, void *to,
			       unsigned long from, ssize_t len)
{
	struct rpcif_hyperbus *hyperbus =
		container_of(hbdev, struct rpcif_hyperbus, hbdev);

	rpcif_hb_prepare_read(&hyperbus->rpc, to, from, len);

	rpcif_dirmap_read(&hyperbus->rpc, from, len, to);
}

static const struct hyperbus_ops rpcif_hb_ops = {
	.read16 = rpcif_hb_read16,
	.write16 = rpcif_hb_write16,
	.copy_from = rpcif_hb_copy_from,
};

static int rpcif_hb_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct rpcif_hyperbus *hyperbus;
	int error;

	hyperbus = devm_kzalloc(dev, sizeof(*hyperbus), GFP_KERNEL);
	if (!hyperbus)
		return -ENOMEM;

	rpcif_sw_init(&hyperbus->rpc, pdev->dev.parent);

	platform_set_drvdata(pdev, hyperbus);

	rpcif_enable_rpm(&hyperbus->rpc);

	rpcif_hw_init(&hyperbus->rpc, true);

	hyperbus->hbdev.map.size = hyperbus->rpc.size;
	hyperbus->hbdev.map.virt = hyperbus->rpc.dirmap;

	hyperbus->ctlr.dev = dev;
	hyperbus->ctlr.ops = &rpcif_hb_ops;
	hyperbus->hbdev.ctlr = &hyperbus->ctlr;
	hyperbus->hbdev.np = of_get_next_child(pdev->dev.parent->of_node, NULL);
	error = hyperbus_register_device(&hyperbus->hbdev);
	if (error)
		rpcif_disable_rpm(&hyperbus->rpc);

	return error;
}

static int rpcif_hb_remove(struct platform_device *pdev)
{
	struct rpcif_hyperbus *hyperbus = platform_get_drvdata(pdev);
	int error = hyperbus_unregister_device(&hyperbus->hbdev);
	struct rpcif *rpc = dev_get_drvdata(pdev->dev.parent);

	rpcif_disable_rpm(rpc);
	return error;
}

static struct platform_driver rpcif_platform_driver = {
	.probe	= rpcif_hb_probe,
	.remove	= rpcif_hb_remove,
	.driver	= {
		.name	= "rpc-if-hyperflash",
	},
};

module_platform_driver(rpcif_platform_driver);

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