2 * drivers/mtd/nand/socrates_nand.c
4 * Copyright © 2008 Ilya Yanok, Emcraft Systems
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
13 #include <linux/slab.h>
14 #include <linux/module.h>
15 #include <linux/mtd/mtd.h>
16 #include <linux/mtd/nand.h>
17 #include <linux/mtd/partitions.h>
18 #include <linux/of_address.h>
19 #include <linux/of_platform.h>
22 #define FPGA_NAND_CMD_MASK (0x7 << 28)
23 #define FPGA_NAND_CMD_COMMAND (0x0 << 28)
24 #define FPGA_NAND_CMD_ADDR (0x1 << 28)
25 #define FPGA_NAND_CMD_READ (0x2 << 28)
26 #define FPGA_NAND_CMD_WRITE (0x3 << 28)
27 #define FPGA_NAND_BUSY (0x1 << 15)
28 #define FPGA_NAND_ENABLE (0x1 << 31)
29 #define FPGA_NAND_DATA_SHIFT 16
31 struct socrates_nand_host
{
32 struct nand_chip nand_chip
;
34 void __iomem
*io_base
;
39 * socrates_nand_write_buf - write buffer to chip
40 * @mtd: MTD device structure
42 * @len: number of bytes to write
44 static void socrates_nand_write_buf(struct mtd_info
*mtd
,
45 const uint8_t *buf
, int len
)
48 struct nand_chip
*this = mtd
->priv
;
49 struct socrates_nand_host
*host
= this->priv
;
51 for (i
= 0; i
< len
; i
++) {
52 out_be32(host
->io_base
, FPGA_NAND_ENABLE
|
54 (buf
[i
] << FPGA_NAND_DATA_SHIFT
));
59 * socrates_nand_read_buf - read chip data into buffer
60 * @mtd: MTD device structure
61 * @buf: buffer to store date
62 * @len: number of bytes to read
64 static void socrates_nand_read_buf(struct mtd_info
*mtd
, uint8_t *buf
, int len
)
67 struct nand_chip
*this = mtd
->priv
;
68 struct socrates_nand_host
*host
= this->priv
;
71 val
= FPGA_NAND_ENABLE
| FPGA_NAND_CMD_READ
;
73 out_be32(host
->io_base
, val
);
74 for (i
= 0; i
< len
; i
++) {
75 buf
[i
] = (in_be32(host
->io_base
) >>
76 FPGA_NAND_DATA_SHIFT
) & 0xff;
81 * socrates_nand_read_byte - read one byte from the chip
82 * @mtd: MTD device structure
84 static uint8_t socrates_nand_read_byte(struct mtd_info
*mtd
)
87 socrates_nand_read_buf(mtd
, &byte
, sizeof(byte
));
92 * socrates_nand_read_word - read one word from the chip
93 * @mtd: MTD device structure
95 static uint16_t socrates_nand_read_word(struct mtd_info
*mtd
)
98 socrates_nand_read_buf(mtd
, (uint8_t *)&word
, sizeof(word
));
103 * Hardware specific access to control-lines
105 static void socrates_nand_cmd_ctrl(struct mtd_info
*mtd
, int cmd
,
108 struct nand_chip
*nand_chip
= mtd
->priv
;
109 struct socrates_nand_host
*host
= nand_chip
->priv
;
112 if (cmd
== NAND_CMD_NONE
)
116 val
= FPGA_NAND_CMD_COMMAND
;
118 val
= FPGA_NAND_CMD_ADDR
;
121 val
|= FPGA_NAND_ENABLE
;
123 val
|= (cmd
& 0xff) << FPGA_NAND_DATA_SHIFT
;
125 out_be32(host
->io_base
, val
);
129 * Read the Device Ready pin.
131 static int socrates_nand_device_ready(struct mtd_info
*mtd
)
133 struct nand_chip
*nand_chip
= mtd
->priv
;
134 struct socrates_nand_host
*host
= nand_chip
->priv
;
136 if (in_be32(host
->io_base
) & FPGA_NAND_BUSY
)
142 * Probe for the NAND device.
144 static int socrates_nand_probe(struct platform_device
*ofdev
)
146 struct socrates_nand_host
*host
;
147 struct mtd_info
*mtd
;
148 struct nand_chip
*nand_chip
;
150 struct mtd_part_parser_data ppdata
;
152 /* Allocate memory for the device structure (and zero it) */
153 host
= devm_kzalloc(&ofdev
->dev
, sizeof(*host
), GFP_KERNEL
);
157 host
->io_base
= of_iomap(ofdev
->dev
.of_node
, 0);
158 if (host
->io_base
== NULL
) {
159 dev_err(&ofdev
->dev
, "ioremap failed\n");
164 nand_chip
= &host
->nand_chip
;
165 host
->dev
= &ofdev
->dev
;
167 nand_chip
->priv
= host
; /* link the private data structures */
168 mtd
->priv
= nand_chip
;
169 mtd
->name
= "socrates_nand";
170 mtd
->owner
= THIS_MODULE
;
171 mtd
->dev
.parent
= &ofdev
->dev
;
172 ppdata
.of_node
= ofdev
->dev
.of_node
;
174 /*should never be accessed directly */
175 nand_chip
->IO_ADDR_R
= (void *)0xdeadbeef;
176 nand_chip
->IO_ADDR_W
= (void *)0xdeadbeef;
178 nand_chip
->cmd_ctrl
= socrates_nand_cmd_ctrl
;
179 nand_chip
->read_byte
= socrates_nand_read_byte
;
180 nand_chip
->read_word
= socrates_nand_read_word
;
181 nand_chip
->write_buf
= socrates_nand_write_buf
;
182 nand_chip
->read_buf
= socrates_nand_read_buf
;
183 nand_chip
->dev_ready
= socrates_nand_device_ready
;
185 nand_chip
->ecc
.mode
= NAND_ECC_SOFT
; /* enable ECC */
187 /* TODO: I have no idea what real delay is. */
188 nand_chip
->chip_delay
= 20; /* 20us command delay time */
190 dev_set_drvdata(&ofdev
->dev
, host
);
192 /* first scan to find the device and get the page size */
193 if (nand_scan_ident(mtd
, 1, NULL
)) {
198 /* second phase scan */
199 if (nand_scan_tail(mtd
)) {
204 res
= mtd_device_parse_register(mtd
, NULL
, &ppdata
, NULL
, 0);
211 iounmap(host
->io_base
);
216 * Remove a NAND device.
218 static int socrates_nand_remove(struct platform_device
*ofdev
)
220 struct socrates_nand_host
*host
= dev_get_drvdata(&ofdev
->dev
);
221 struct mtd_info
*mtd
= &host
->mtd
;
225 iounmap(host
->io_base
);
230 static const struct of_device_id socrates_nand_match
[] =
233 .compatible
= "abb,socrates-nand",
238 MODULE_DEVICE_TABLE(of
, socrates_nand_match
);
240 static struct platform_driver socrates_nand_driver
= {
242 .name
= "socrates_nand",
243 .owner
= THIS_MODULE
,
244 .of_match_table
= socrates_nand_match
,
246 .probe
= socrates_nand_probe
,
247 .remove
= socrates_nand_remove
,
250 module_platform_driver(socrates_nand_driver
);
252 MODULE_LICENSE("GPL");
253 MODULE_AUTHOR("Ilya Yanok");
254 MODULE_DESCRIPTION("NAND driver for Socrates board");