summaryrefslogtreecommitdiffstats
path: root/kernel/drivers/mtd/nand/orion_nand.c
blob: ee83749fb1d355e67dbcb07c98b187f1e52e2a1a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
/*
 * drivers/mtd/nand/orion_nand.c
 *
 * NAND support for Marvell Orion SoC platforms
 *
 * Tzachi Perelstein <tzachi@marvell.com>
 *
 * This file is licensed under  the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/partitions.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <asm/sizes.h>
#include <linux/platform_data/mtd-orion_nand.h>

static void orion_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
	struct nand_chip *nc = mtd->priv;
	struct orion_nand_data *board = nc->priv;
	u32 offs;

	if (cmd == NAND_CMD_NONE)
		return;

	if (ctrl & NAND_CLE)
		offs = (1 << board->cle);
	else if (ctrl & NAND_ALE)
		offs = (1 << board->ale);
	else
		return;

	if (nc->options & NAND_BUSWIDTH_16)
		offs <<= 1;

	writeb(cmd, nc->IO_ADDR_W + offs);
}

static void orion_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
{
	struct nand_chip *chip = mtd->priv;
	void __iomem *io_base = chip->IO_ADDR_R;
	uint64_t *buf64;
	int i = 0;

	while (len && (unsigned long)buf & 7) {
		*buf++ = readb(io_base);
		len--;
	}
	buf64 = (uint64_t *)buf;
	while (i < len/8) {
		/*
		 * Since GCC has no proper constraint (PR 43518)
		 * force x variable to r2/r3 registers as ldrd instruction
		 * requires first register to be even.
		 */
		register uint64_t x asm ("r2");

		asm volatile ("ldrd\t%0, [%1]" : "=&r" (x) : "r" (io_base));
		buf64[i++] = x;
	}
	i *= 8;
	while (i < len)
		buf[i++] = readb(io_base);
}

static int __init orion_nand_probe(struct platform_device *pdev)
{
	struct mtd_info *mtd;
	struct mtd_part_parser_data ppdata = {};
	struct nand_chip *nc;
	struct orion_nand_data *board;
	struct resource *res;
	struct clk *clk;
	void __iomem *io_base;
	int ret = 0;
	u32 val = 0;

	nc = devm_kzalloc(&pdev->dev,
			sizeof(struct nand_chip) + sizeof(struct mtd_info),
			GFP_KERNEL);
	if (!nc)
		return -ENOMEM;
	mtd = (struct mtd_info *)(nc + 1);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	io_base = devm_ioremap_resource(&pdev->dev, res);

	if (IS_ERR(io_base))
		return PTR_ERR(io_base);

	if (pdev->dev.of_node) {
		board = devm_kzalloc(&pdev->dev, sizeof(struct orion_nand_data),
					GFP_KERNEL);
		if (!board)
			return -ENOMEM;
		if (!of_property_read_u32(pdev->dev.of_node, "cle", &val))
			board->cle = (u8)val;
		else
			board->cle = 0;
		if (!of_property_read_u32(pdev->dev.of_node, "ale", &val))
			board->ale = (u8)val;
		else
			board->ale = 1;
		if (!of_property_read_u32(pdev->dev.of_node,
						"bank-width", &val))
			board->width = (u8)val * 8;
		else
			board->width = 8;
		if (!of_property_read_u32(pdev->dev.of_node,
						"chip-delay", &val))
			board->chip_delay = (u8)val;
	} else {
		board = dev_get_platdata(&pdev->dev);
	}

	mtd->priv = nc;
	mtd->dev.parent = &pdev->dev;

	nc->priv = board;
	nc->IO_ADDR_R = nc->IO_ADDR_W = io_base;
	nc->cmd_ctrl = orion_nand_cmd_ctrl;
	nc->read_buf = orion_nand_read_buf;
	nc->ecc.mode = NAND_ECC_SOFT;

	if (board->chip_delay)
		nc->chip_delay = board->chip_delay;

	WARN(board->width > 16,
		"%d bit bus width out of range",
		board->width);

	if (board->width == 16)
		nc->options |= NAND_BUSWIDTH_16;

	if (board->dev_ready)
		nc->dev_ready = board->dev_ready;

	platform_set_drvdata(pdev, mtd);

	/* Not all platforms can gate the clock, so it is not
	   an error if the clock does not exists. */
	clk = clk_get(&pdev->dev, NULL);
	if (!IS_ERR(clk)) {
		clk_prepare_enable(clk);
		clk_put(clk);
	}

	if (nand_scan(mtd, 1)) {
		ret = -ENXIO;
		goto no_dev;
	}

	mtd->name = "orion_nand";
	ppdata.of_node = pdev->dev.of_node;
	ret = mtd_device_parse_register(mtd, NULL, &ppdata,
			board->parts, board->nr_parts);
	if (ret) {
		nand_release(mtd);
		goto no_dev;
	}

	return 0;

no_dev:
	if (!IS_ERR(clk)) {
		clk_disable_unprepare(clk);
		clk_put(clk);
	}

	return ret;
}

static int orion_nand_remove(struct platform_device *pdev)
{
	struct mtd_info *mtd = platform_get_drvdata(pdev);
	struct clk *clk;

	nand_release(mtd);

	clk = clk_get(&pdev->dev, NULL);
	if (!IS_ERR(clk)) {
		clk_disable_unprepare(clk);
		clk_put(clk);
	}

	return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id orion_nand_of_match_table[] = {
	{ .compatible = "marvell,orion-nand", },
	{},
};
MODULE_DEVICE_TABLE(of, orion_nand_of_match_table);
#endif

static struct platform_driver orion_nand_driver = {
	.remove		= orion_nand_remove,
	.driver		= {
		.name	= "orion_nand",
		.of_match_table = of_match_ptr(orion_nand_of_match_table),
	},
};

module_platform_driver_probe(orion_nand_driver, orion_nand_probe);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Tzachi Perelstein");
MODULE_DESCRIPTION("NAND glue for Orion platforms");
MODULE_ALIAS("platform:orion_nand");