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	struct resource *res;
44	const char **part_types;
45	int err = 0;
46
47	if (!pdata) {
48		dev_err(&pdev->dev, "platform_nand_data is missing\n");
49		return -EINVAL;
50	}
51
52	if (pdata->chip.nr_chips < 1) {
53		dev_err(&pdev->dev, "invalid number of chips specified\n");
54		return -EINVAL;
55	}
56
57	/* Allocate memory for the device structure (and zero it) */
58	data = devm_kzalloc(&pdev->dev, sizeof(struct plat_nand_data),
59			    GFP_KERNEL);
60	if (!data)
61		return -ENOMEM;
62
63	data->controller.ops = &plat_nand_ops;
64	nand_controller_init(&data->controller);
65	data->chip.controller = &data->controller;
66
67	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
68	data->io_base = devm_ioremap_resource(&pdev->dev, res);
69	if (IS_ERR(data->io_base))
70		return PTR_ERR(data->io_base);
71
72	nand_set_flash_node(&data->chip, pdev->dev.of_node);
73	mtd = nand_to_mtd(&data->chip);
74	mtd->dev.parent = &pdev->dev;
75
76	data->chip.legacy.IO_ADDR_R = data->io_base;
77	data->chip.legacy.IO_ADDR_W = data->io_base;
78	data->chip.legacy.cmd_ctrl = pdata->ctrl.cmd_ctrl;
79	data->chip.legacy.dev_ready = pdata->ctrl.dev_ready;
80	data->chip.legacy.select_chip = pdata->ctrl.select_chip;
81	data->chip.legacy.write_buf = pdata->ctrl.write_buf;
82	data->chip.legacy.read_buf = pdata->ctrl.read_buf;
83	data->chip.legacy.chip_delay = pdata->chip.chip_delay;
84	data->chip.options |= pdata->chip.options;
85	data->chip.bbt_options |= pdata->chip.bbt_options;
86
87	platform_set_drvdata(pdev, data);
88
89	/* Handle any platform specific setup */
90	if (pdata->ctrl.probe) {
91		err = pdata->ctrl.probe(pdev);
92		if (err)
93			goto out;
94	}
95
96	/*
97	 * This driver assumes that the default ECC engine should be TYPE_SOFT.
98	 * Set ->engine_type before registering the NAND devices in order to
99	 * provide a driver specific default value.
100	 */
101	data->chip.ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
102
103	/* Scan to find existence of the device */
104	err = nand_scan(&data->chip, pdata->chip.nr_chips);
105	if (err)
106		goto out;
107
108	part_types = pdata->chip.part_probe_types;
109
110	err = mtd_device_parse_register(mtd, part_types, NULL,
111					pdata->chip.partitions,
112					pdata->chip.nr_partitions);
113
114	if (!err)
115		return err;
116
117	nand_cleanup(&data->chip);
118out:
119	if (pdata->ctrl.remove)
120		pdata->ctrl.remove(pdev);
121	return err;
122}
123
124/*
125 * Remove a NAND device.
126 */
127static int plat_nand_remove(struct platform_device *pdev)
128{
129	struct plat_nand_data *data = platform_get_drvdata(pdev);
130	struct platform_nand_data *pdata = dev_get_platdata(&pdev->dev);
131	struct nand_chip *chip = &data->chip;
132	int ret;
133
134	ret = mtd_device_unregister(nand_to_mtd(chip));
135	WARN_ON(ret);
136	nand_cleanup(chip);
137	if (pdata->ctrl.remove)
138		pdata->ctrl.remove(pdev);
139
140	return 0;
141}
142
143static const struct of_device_id plat_nand_match[] = {
144	{ .compatible = "gen_nand" },
145	{},
146};
147MODULE_DEVICE_TABLE(of, plat_nand_match);
148
149static struct platform_driver plat_nand_driver = {
150	.probe	= plat_nand_probe,
151	.remove	= plat_nand_remove,
152	.driver	= {
153		.name		= "gen_nand",
154		.of_match_table = plat_nand_match,
155	},
156};
157
158module_platform_driver(plat_nand_driver);
159
160MODULE_LICENSE("GPL");
161MODULE_AUTHOR("Vitaly Wool");
162MODULE_DESCRIPTION("Simple generic NAND driver");
163MODULE_ALIAS("platform:gen_nand");
164