// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Freescale UPM NAND driver.
 *
 * Copyright © 2007-2008  MontaVista Software, Inc.
 *
 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/mtd/rawnand.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/mtd.h>
#include <linux/of_platform.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <asm/fsl_lbc.h>

struct fsl_upm_nand {
	struct nand_controller base;
	struct device *dev;
	struct nand_chip chip;
	struct fsl_upm upm;
	uint8_t upm_addr_offset;
	uint8_t upm_cmd_offset;
	void __iomem *io_base;
	struct gpio_desc *rnb_gpio[NAND_MAX_CHIPS];
	uint32_t mchip_offsets[NAND_MAX_CHIPS];
	uint32_t mchip_count;
	uint32_t mchip_number;
};

static inline struct fsl_upm_nand *to_fsl_upm_nand(struct mtd_info *mtdinfo)
{
	return container_of(mtd_to_nand(mtdinfo), struct fsl_upm_nand,
			    chip);
}

static int fun_chip_init(struct fsl_upm_nand *fun,
			 const struct device_node *upm_np,
			 const struct resource *io_res)
{
	struct mtd_info *mtd = nand_to_mtd(&fun->chip);
	int ret;
	struct device_node *flash_np;

	fun->chip.ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
	fun->chip.ecc.algo = NAND_ECC_ALGO_HAMMING;
	fun->chip.controller = &fun->base;
	mtd->dev.parent = fun->dev;

	flash_np = of_get_next_child(upm_np, NULL);
	if (!flash_np)
		return -ENODEV;

	nand_set_flash_node(&fun->chip, flash_np);
	mtd->name = devm_kasprintf(fun->dev, GFP_KERNEL, "0x%llx.%pOFn",
				   (u64)io_res->start,
				   flash_np);
	if (!mtd->name) {
		ret = -ENOMEM;
		goto err;
	}

	ret = nand_scan(&fun->chip, fun->mchip_count);
	if (ret)
		goto err;

	ret = mtd_device_register(mtd, NULL, 0);
err:
	of_node_put(flash_np);
	return ret;
}

static int func_exec_instr(struct nand_chip *chip,
			   const struct nand_op_instr *instr)
{
	struct fsl_upm_nand *fun = to_fsl_upm_nand(nand_to_mtd(chip));
	u32 mar, reg_offs = fun->mchip_offsets[fun->mchip_number];
	unsigned int i;
	const u8 *out;
	u8 *in;

	switch (instr->type) {
	case NAND_OP_CMD_INSTR:
		fsl_upm_start_pattern(&fun->upm, fun->upm_cmd_offset);
		mar = (instr->ctx.cmd.opcode << (32 - fun->upm.width)) |
		      reg_offs;
		fsl_upm_run_pattern(&fun->upm, fun->io_base + reg_offs, mar);
		fsl_upm_end_pattern(&fun->upm);
		return 0;

	case NAND_OP_ADDR_INSTR:
		fsl_upm_start_pattern(&fun->upm, fun->upm_addr_offset);
		for (i = 0; i < instr->ctx.addr.naddrs; i++) {
			mar = (instr->ctx.addr.addrs[i] << (32 - fun->upm.width)) |
			      reg_offs;
			fsl_upm_run_pattern(&fun->upm, fun->io_base + reg_offs, mar);
		}
		fsl_upm_end_pattern(&fun->upm);
		return 0;

	case NAND_OP_DATA_IN_INSTR:
		in = instr->ctx.data.buf.in;
		for (i = 0; i < instr->ctx.data.len; i++)
			in[i] = in_8(fun->io_base + reg_offs);
		return 0;

	case NAND_OP_DATA_OUT_INSTR:
		out = instr->ctx.data.buf.out;
		for (i = 0; i < instr->ctx.data.len; i++)
			out_8(fun->io_base + reg_offs, out[i]);
		return 0;

	case NAND_OP_WAITRDY_INSTR:
		if (!fun->rnb_gpio[fun->mchip_number])
			return nand_soft_waitrdy(chip, instr->ctx.waitrdy.timeout_ms);

		return nand_gpio_waitrdy(chip, fun->rnb_gpio[fun->mchip_number],
					 instr->ctx.waitrdy.timeout_ms);

	default:
		return -EINVAL;
	}

	return 0;
}

static int fun_exec_op(struct nand_chip *chip, const struct nand_operation *op,
		       bool check_only)
{
	struct fsl_upm_nand *fun = to_fsl_upm_nand(nand_to_mtd(chip));
	unsigned int i;
	int ret;

	if (op->cs > NAND_MAX_CHIPS)
		return -EINVAL;

	if (check_only)
		return 0;

	fun->mchip_number = op->cs;

	for (i = 0; i < op->ninstrs; i++) {
		ret = func_exec_instr(chip, &op->instrs[i]);
		if (ret)
			return ret;

		if (op->instrs[i].delay_ns)
			ndelay(op->instrs[i].delay_ns);
	}

	return 0;
}

static const struct nand_controller_ops fun_ops = {
	.exec_op = fun_exec_op,
};

static int fun_probe(struct platform_device *ofdev)
{
	struct fsl_upm_nand *fun;
	struct resource *io_res;
	const __be32 *prop;
	int ret;
	int size;
	int i;

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

	io_res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
	fun->io_base = devm_ioremap_resource(&ofdev->dev, io_res);
	if (IS_ERR(fun->io_base))
		return PTR_ERR(fun->io_base);

	ret = fsl_upm_find(io_res->start, &fun->upm);
	if (ret) {
		dev_err(&ofdev->dev, "can't find UPM\n");
		return ret;
	}

	prop = of_get_property(ofdev->dev.of_node, "fsl,upm-addr-offset",
			       &size);
	if (!prop || size != sizeof(uint32_t)) {
		dev_err(&ofdev->dev, "can't get UPM address offset\n");
		return -EINVAL;
	}
	fun->upm_addr_offset = *prop;

	prop = of_get_property(ofdev->dev.of_node, "fsl,upm-cmd-offset", &size);
	if (!prop || size != sizeof(uint32_t)) {
		dev_err(&ofdev->dev, "can't get UPM command offset\n");
		return -EINVAL;
	}
	fun->upm_cmd_offset = *prop;

	prop = of_get_property(ofdev->dev.of_node,
			       "fsl,upm-addr-line-cs-offsets", &size);
	if (prop && (size / sizeof(uint32_t)) > 0) {
		fun->mchip_count = size / sizeof(uint32_t);
		if (fun->mchip_count >= NAND_MAX_CHIPS) {
			dev_err(&ofdev->dev, "too much multiple chips\n");
			return -EINVAL;
		}
		for (i = 0; i < fun->mchip_count; i++)
			fun->mchip_offsets[i] = be32_to_cpu(prop[i]);
	} else {
		fun->mchip_count = 1;
	}

	for (i = 0; i < fun->mchip_count; i++) {
		fun->rnb_gpio[i] = devm_gpiod_get_index_optional(&ofdev->dev,
								 NULL, i,
								 GPIOD_IN);
		if (IS_ERR(fun->rnb_gpio[i])) {
			dev_err(&ofdev->dev, "RNB gpio #%d is invalid\n", i);
			return PTR_ERR(fun->rnb_gpio[i]);
		}
	}

	nand_controller_init(&fun->base);
	fun->base.ops = &fun_ops;
	fun->dev = &ofdev->dev;

	ret = fun_chip_init(fun, ofdev->dev.of_node, io_res);
	if (ret)
		return ret;

	dev_set_drvdata(&ofdev->dev, fun);

	return 0;
}

static int fun_remove(struct platform_device *ofdev)
{
	struct fsl_upm_nand *fun = dev_get_drvdata(&ofdev->dev);
	struct nand_chip *chip = &fun->chip;
	struct mtd_info *mtd = nand_to_mtd(chip);
	int ret;

	ret = mtd_device_unregister(mtd);
	WARN_ON(ret);
	nand_cleanup(chip);

	return 0;
}

static const struct of_device_id of_fun_match[] = {
	{ .compatible = "fsl,upm-nand" },
	{},
};
MODULE_DEVICE_TABLE(of, of_fun_match);

static struct platform_driver of_fun_driver = {
	.driver = {
		.name = "fsl,upm-nand",
		.of_match_table = of_fun_match,
	},
	.probe		= fun_probe,
	.remove		= fun_remove,
};

module_platform_driver(of_fun_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
MODULE_DESCRIPTION("Driver for NAND chips working through Freescale "
		   "LocalBus User-Programmable Machine");