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 
16 struct plat_nand_data {
17 	struct nand_controller	controller;
18 	struct nand_chip	chip;
19 	void __iomem		*io_base;
20 };
21 
plat_nand_attach_chip(struct nand_chip * chip)22 static 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 
31 static 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  */
plat_nand_probe(struct platform_device * pdev)38 static 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);
116 out:
117 	if (pdata->ctrl.remove)
118 		pdata->ctrl.remove(pdev);
119 	return err;
120 }
121 
122 /*
123  * Remove a NAND device.
124  */
plat_nand_remove(struct platform_device * pdev)125 static int 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 	return 0;
139 }
140 
141 static const struct of_device_id plat_nand_match[] = {
142 	{ .compatible = "gen_nand" },
143 	{},
144 };
145 MODULE_DEVICE_TABLE(of, plat_nand_match);
146 
147 static struct platform_driver plat_nand_driver = {
148 	.probe	= plat_nand_probe,
149 	.remove	= plat_nand_remove,
150 	.driver	= {
151 		.name		= "gen_nand",
152 		.of_match_table = plat_nand_match,
153 	},
154 };
155 
156 module_platform_driver(plat_nand_driver);
157 
158 MODULE_LICENSE("GPL");
159 MODULE_AUTHOR("Vitaly Wool");
160 MODULE_DESCRIPTION("Simple generic NAND driver");
161 MODULE_ALIAS("platform:gen_nand");
162