Root/target/linux/ar71xx/files/drivers/mtd/nand/rb4xx_nand.c

1/*
2 * NAND flash driver for the MikroTik RouterBoard 4xx series
3 *
4 * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
5 * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
6 *
7 * This file was based on the driver for Linux 2.6.22 published by
8 * MikroTik for their RouterBoard 4xx series devices.
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License version 2 as published
12 * by the Free Software Foundation.
13 */
14
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/init.h>
18#include <linux/mtd/nand.h>
19#include <linux/mtd/mtd.h>
20#include <linux/mtd/partitions.h>
21#include <linux/platform_device.h>
22#include <linux/delay.h>
23#include <linux/io.h>
24#include <linux/gpio.h>
25#include <linux/slab.h>
26
27#include <asm/mach-ath79/ath79.h>
28#include <asm/mach-ath79/rb4xx_cpld.h>
29
30#define DRV_NAME "rb4xx-nand"
31#define DRV_VERSION "0.2.0"
32#define DRV_DESC "NAND flash driver for RouterBoard 4xx series"
33
34#define RB4XX_NAND_GPIO_READY 5
35#define RB4XX_NAND_GPIO_ALE 37
36#define RB4XX_NAND_GPIO_CLE 38
37#define RB4XX_NAND_GPIO_NCE 39
38
39struct rb4xx_nand_info {
40    struct nand_chip chip;
41    struct mtd_info mtd;
42};
43
44/*
45 * We need to use the OLD Yaffs-1 OOB layout, otherwise the RB bootloader
46 * will not be able to find the kernel that we load.
47 */
48static struct nand_ecclayout rb4xx_nand_ecclayout = {
49    .eccbytes = 6,
50    .eccpos = { 8, 9, 10, 13, 14, 15 },
51    .oobavail = 9,
52    .oobfree = { { 0, 4 }, { 6, 2 }, { 11, 2 }, { 4, 1 } }
53};
54
55static struct mtd_partition rb4xx_nand_partitions[] = {
56    {
57        .name = "booter",
58        .offset = 0,
59        .size = (256 * 1024),
60        .mask_flags = MTD_WRITEABLE,
61    },
62    {
63        .name = "kernel",
64        .offset = (256 * 1024),
65        .size = (4 * 1024 * 1024) - (256 * 1024),
66    },
67    {
68        .name = "rootfs",
69        .offset = MTDPART_OFS_NXTBLK,
70        .size = MTDPART_SIZ_FULL,
71    },
72};
73
74static int rb4xx_nand_dev_ready(struct mtd_info *mtd)
75{
76    return gpio_get_value_cansleep(RB4XX_NAND_GPIO_READY);
77}
78
79static void rb4xx_nand_write_cmd(unsigned char cmd)
80{
81    unsigned char data = cmd;
82    int err;
83
84    err = rb4xx_cpld_write(&data, 1);
85    if (err)
86        pr_err("rb4xx_nand: write cmd failed, err=%d\n", err);
87}
88
89static void rb4xx_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
90                unsigned int ctrl)
91{
92    if (ctrl & NAND_CTRL_CHANGE) {
93        gpio_set_value_cansleep(RB4XX_NAND_GPIO_CLE,
94                    (ctrl & NAND_CLE) ? 1 : 0);
95        gpio_set_value_cansleep(RB4XX_NAND_GPIO_ALE,
96                    (ctrl & NAND_ALE) ? 1 : 0);
97        gpio_set_value_cansleep(RB4XX_NAND_GPIO_NCE,
98                    (ctrl & NAND_NCE) ? 0 : 1);
99    }
100
101    if (cmd != NAND_CMD_NONE)
102        rb4xx_nand_write_cmd(cmd);
103}
104
105static unsigned char rb4xx_nand_read_byte(struct mtd_info *mtd)
106{
107    unsigned char data = 0;
108    int err;
109
110    err = rb4xx_cpld_read(&data, NULL, 1);
111    if (err) {
112        pr_err("rb4xx_nand: read data failed, err=%d\n", err);
113        data = 0xff;
114    }
115
116    return data;
117}
118
119static void rb4xx_nand_write_buf(struct mtd_info *mtd, const unsigned char *buf,
120                 int len)
121{
122    int err;
123
124    err = rb4xx_cpld_write(buf, len);
125    if (err)
126        pr_err("rb4xx_nand: write buf failed, err=%d\n", err);
127}
128
129static void rb4xx_nand_read_buf(struct mtd_info *mtd, unsigned char *buf,
130                int len)
131{
132    int err;
133
134    err = rb4xx_cpld_read(buf, NULL, len);
135    if (err)
136        pr_err("rb4xx_nand: read buf failed, err=%d\n", err);
137}
138
139static int __devinit rb4xx_nand_probe(struct platform_device *pdev)
140{
141    struct rb4xx_nand_info *info;
142    int ret;
143
144    printk(KERN_INFO DRV_DESC " version " DRV_VERSION "\n");
145
146    ret = gpio_request(RB4XX_NAND_GPIO_READY, "NAND RDY");
147    if (ret) {
148        dev_err(&pdev->dev, "unable to request gpio %d\n",
149            RB4XX_NAND_GPIO_READY);
150        goto err;
151    }
152
153    ret = gpio_direction_input(RB4XX_NAND_GPIO_READY);
154    if (ret) {
155        dev_err(&pdev->dev, "unable to set input mode on gpio %d\n",
156            RB4XX_NAND_GPIO_READY);
157        goto err_free_gpio_ready;
158    }
159
160    ret = gpio_request(RB4XX_NAND_GPIO_ALE, "NAND ALE");
161    if (ret) {
162        dev_err(&pdev->dev, "unable to request gpio %d\n",
163            RB4XX_NAND_GPIO_ALE);
164        goto err_free_gpio_ready;
165    }
166
167    ret = gpio_direction_output(RB4XX_NAND_GPIO_ALE, 0);
168    if (ret) {
169        dev_err(&pdev->dev, "unable to set output mode on gpio %d\n",
170            RB4XX_NAND_GPIO_ALE);
171        goto err_free_gpio_ale;
172    }
173
174    ret = gpio_request(RB4XX_NAND_GPIO_CLE, "NAND CLE");
175    if (ret) {
176        dev_err(&pdev->dev, "unable to request gpio %d\n",
177            RB4XX_NAND_GPIO_CLE);
178        goto err_free_gpio_ale;
179    }
180
181    ret = gpio_direction_output(RB4XX_NAND_GPIO_CLE, 0);
182    if (ret) {
183        dev_err(&pdev->dev, "unable to set output mode on gpio %d\n",
184            RB4XX_NAND_GPIO_CLE);
185        goto err_free_gpio_cle;
186    }
187
188    ret = gpio_request(RB4XX_NAND_GPIO_NCE, "NAND NCE");
189    if (ret) {
190        dev_err(&pdev->dev, "unable to request gpio %d\n",
191            RB4XX_NAND_GPIO_NCE);
192        goto err_free_gpio_cle;
193    }
194
195    ret = gpio_direction_output(RB4XX_NAND_GPIO_NCE, 1);
196    if (ret) {
197        dev_err(&pdev->dev, "unable to set output mode on gpio %d\n",
198            RB4XX_NAND_GPIO_ALE);
199        goto err_free_gpio_nce;
200    }
201
202    info = kzalloc(sizeof(*info), GFP_KERNEL);
203    if (!info) {
204        dev_err(&pdev->dev, "rb4xx-nand: no memory for private data\n");
205        ret = -ENOMEM;
206        goto err_free_gpio_nce;
207    }
208
209    info->chip.priv = &info;
210    info->mtd.priv = &info->chip;
211    info->mtd.owner = THIS_MODULE;
212
213    info->chip.cmd_ctrl = rb4xx_nand_cmd_ctrl;
214    info->chip.dev_ready = rb4xx_nand_dev_ready;
215    info->chip.read_byte = rb4xx_nand_read_byte;
216    info->chip.write_buf = rb4xx_nand_write_buf;
217    info->chip.read_buf = rb4xx_nand_read_buf;
218
219    info->chip.chip_delay = 25;
220    info->chip.ecc.mode = NAND_ECC_SOFT;
221
222    platform_set_drvdata(pdev, info);
223
224    ret = nand_scan_ident(&info->mtd, 1, NULL);
225    if (ret) {
226        ret = -ENXIO;
227        goto err_free_info;
228    }
229
230    if (info->mtd.writesize == 512)
231        info->chip.ecc.layout = &rb4xx_nand_ecclayout;
232
233    ret = nand_scan_tail(&info->mtd);
234    if (ret) {
235        return -ENXIO;
236        goto err_set_drvdata;
237    }
238
239    mtd_device_register(&info->mtd, rb4xx_nand_partitions,
240                ARRAY_SIZE(rb4xx_nand_partitions));
241    if (ret)
242        goto err_release_nand;
243
244    return 0;
245
246err_release_nand:
247    nand_release(&info->mtd);
248err_set_drvdata:
249    platform_set_drvdata(pdev, NULL);
250err_free_info:
251    kfree(info);
252err_free_gpio_nce:
253    gpio_free(RB4XX_NAND_GPIO_NCE);
254err_free_gpio_cle:
255    gpio_free(RB4XX_NAND_GPIO_CLE);
256err_free_gpio_ale:
257    gpio_free(RB4XX_NAND_GPIO_ALE);
258err_free_gpio_ready:
259    gpio_free(RB4XX_NAND_GPIO_READY);
260err:
261    return ret;
262}
263
264static int __devexit rb4xx_nand_remove(struct platform_device *pdev)
265{
266    struct rb4xx_nand_info *info = platform_get_drvdata(pdev);
267
268    nand_release(&info->mtd);
269    platform_set_drvdata(pdev, NULL);
270    kfree(info);
271    gpio_free(RB4XX_NAND_GPIO_NCE);
272    gpio_free(RB4XX_NAND_GPIO_CLE);
273    gpio_free(RB4XX_NAND_GPIO_ALE);
274    gpio_free(RB4XX_NAND_GPIO_READY);
275
276    return 0;
277}
278
279static struct platform_driver rb4xx_nand_driver = {
280    .probe = rb4xx_nand_probe,
281    .remove = __devexit_p(rb4xx_nand_remove),
282    .driver = {
283        .name = DRV_NAME,
284        .owner = THIS_MODULE,
285    },
286};
287
288static int __init rb4xx_nand_init(void)
289{
290    return platform_driver_register(&rb4xx_nand_driver);
291}
292
293static void __exit rb4xx_nand_exit(void)
294{
295    platform_driver_unregister(&rb4xx_nand_driver);
296}
297
298module_init(rb4xx_nand_init);
299module_exit(rb4xx_nand_exit);
300
301MODULE_DESCRIPTION(DRV_DESC);
302MODULE_VERSION(DRV_VERSION);
303MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
304MODULE_AUTHOR("Imre Kaloz <kaloz@openwrt.org>");
305MODULE_LICENSE("GPL v2");
306

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