1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Generic NAND driver
  4 *
  5 * Author: Vitaly Wool <vitalywool@gmail.com>
  6 */
  7
  8#include <linux/err.h>
  9#include <linux/io.h>
 10#include <linux/module.h>
 11#include <linux/platform_device.h>
 12#include <linux/slab.h>
 13#include <linux/mtd/mtd.h>
 14#include <linux/mtd/platnand.h>
 15
 16struct plat_nand_data {
 17	struct nand_controller	controller;
 18	struct nand_chip	chip;
 19	void __iomem		*io_base;
 20};
 21
 22static int plat_nand_attach_chip(struct nand_chip *chip)
 23{
 24	if (chip->ecc.engine_type == NAND_ECC_ENGINE_TYPE_SOFT &&
 25	    chip->ecc.algo == NAND_ECC_ALGO_UNKNOWN)
 26		chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
 27
 28	return 0;
 29}
 30
 31static const struct nand_controller_ops plat_nand_ops = {
 32	.attach_chip = plat_nand_attach_chip,
 33};
 34
 35/*
 36 * Probe for the NAND device.
 37 */
 38static int plat_nand_probe(struct platform_device *pdev)
 39{
 40	struct platform_nand_data *pdata = dev_get_platdata(&pdev->dev);
 41	struct plat_nand_data *data;
 42	struct mtd_info *mtd;
 43	const char **part_types;
 44	int err = 0;
 45
 46	if (!pdata) {
 47		dev_err(&pdev->dev, "platform_nand_data is missing\n");
 48		return -EINVAL;
 49	}
 50
 51	if (pdata->chip.nr_chips < 1) {
 52		dev_err(&pdev->dev, "invalid number of chips specified\n");
 53		return -EINVAL;
 54	}
 55
 56	/* Allocate memory for the device structure (and zero it) */
 57	data = devm_kzalloc(&pdev->dev, sizeof(struct plat_nand_data),
 58			    GFP_KERNEL);
 59	if (!data)
 60		return -ENOMEM;
 61
 62	data->controller.ops = &plat_nand_ops;
 63	nand_controller_init(&data->controller);
 64	data->chip.controller = &data->controller;
 65
 66	data->io_base = devm_platform_ioremap_resource(pdev, 0);
 67	if (IS_ERR(data->io_base))
 68		return PTR_ERR(data->io_base);
 69
 70	nand_set_flash_node(&data->chip, pdev->dev.of_node);
 71	mtd = nand_to_mtd(&data->chip);
 72	mtd->dev.parent = &pdev->dev;
 73
 74	data->chip.legacy.IO_ADDR_R = data->io_base;
 75	data->chip.legacy.IO_ADDR_W = data->io_base;
 76	data->chip.legacy.cmd_ctrl = pdata->ctrl.cmd_ctrl;
 77	data->chip.legacy.dev_ready = pdata->ctrl.dev_ready;
 78	data->chip.legacy.select_chip = pdata->ctrl.select_chip;
 79	data->chip.legacy.write_buf = pdata->ctrl.write_buf;
 80	data->chip.legacy.read_buf = pdata->ctrl.read_buf;
 81	data->chip.legacy.chip_delay = pdata->chip.chip_delay;
 82	data->chip.options |= pdata->chip.options;
 83	data->chip.bbt_options |= pdata->chip.bbt_options;
 84
 85	platform_set_drvdata(pdev, data);
 86
 87	/* Handle any platform specific setup */
 88	if (pdata->ctrl.probe) {
 89		err = pdata->ctrl.probe(pdev);
 90		if (err)
 91			goto out;
 92	}
 93
 94	/*
 95	 * This driver assumes that the default ECC engine should be TYPE_SOFT.
 96	 * Set ->engine_type before registering the NAND devices in order to
 97	 * provide a driver specific default value.
 98	 */
 99	data->chip.ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
100
101	/* Scan to find existence of the device */
102	err = nand_scan(&data->chip, pdata->chip.nr_chips);
103	if (err)
104		goto out;
105
106	part_types = pdata->chip.part_probe_types;
107
108	err = mtd_device_parse_register(mtd, part_types, NULL,
109					pdata->chip.partitions,
110					pdata->chip.nr_partitions);
111
112	if (!err)
113		return err;
114
115	nand_cleanup(&data->chip);
116out:
117	if (pdata->ctrl.remove)
118		pdata->ctrl.remove(pdev);
119	return err;
120}
121
122/*
123 * Remove a NAND device.
124 */
125static void plat_nand_remove(struct platform_device *pdev)
126{
127	struct plat_nand_data *data = platform_get_drvdata(pdev);
128	struct platform_nand_data *pdata = dev_get_platdata(&pdev->dev);
129	struct nand_chip *chip = &data->chip;
130	int ret;
131
132	ret = mtd_device_unregister(nand_to_mtd(chip));
133	WARN_ON(ret);
134	nand_cleanup(chip);
135	if (pdata->ctrl.remove)
136		pdata->ctrl.remove(pdev);
137}
138
139static const struct of_device_id plat_nand_match[] = {
140	{ .compatible = "gen_nand" },
141	{},
142};
143MODULE_DEVICE_TABLE(of, plat_nand_match);
144
145static struct platform_driver plat_nand_driver = {
146	.probe	= plat_nand_probe,
147	.remove = plat_nand_remove,
148	.driver	= {
149		.name		= "gen_nand",
150		.of_match_table = plat_nand_match,
151	},
152};
153
154module_platform_driver(plat_nand_driver);
155
156MODULE_LICENSE("GPL");
157MODULE_AUTHOR("Vitaly Wool");
158MODULE_DESCRIPTION("Simple generic NAND driver");
159MODULE_ALIAS("platform:gen_nand");