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#if 0
219	info->chip.verify_buf	= rb4xx_nand_verify_buf;
220#endif
221
222	info->chip.chip_delay	= 25;
223	info->chip.ecc.mode	= NAND_ECC_SOFT;
224	info->chip.options	|= NAND_NO_AUTOINCR;
225
226	platform_set_drvdata(pdev, info);
227
228	ret = nand_scan_ident(&info->mtd, 1, NULL);
229	if (ret) {
230		ret = -ENXIO;
231		goto err_free_info;
232	}
233
234	if (info->mtd.writesize == 512)
235		info->chip.ecc.layout = &rb4xx_nand_ecclayout;
236
237	ret = nand_scan_tail(&info->mtd);
238	if (ret) {
239		return -ENXIO;
240		goto err_set_drvdata;
241	}
242
243	mtd_device_register(&info->mtd, rb4xx_nand_partitions,
244				ARRAY_SIZE(rb4xx_nand_partitions));
245	if (ret)
246		goto err_release_nand;
247
248	return 0;
249
250err_release_nand:
251	nand_release(&info->mtd);
252err_set_drvdata:
253	platform_set_drvdata(pdev, NULL);
254err_free_info:
255	kfree(info);
256err_free_gpio_nce:
257	gpio_free(RB4XX_NAND_GPIO_NCE);
258err_free_gpio_cle:
259	gpio_free(RB4XX_NAND_GPIO_CLE);
260err_free_gpio_ale:
261	gpio_free(RB4XX_NAND_GPIO_ALE);
262err_free_gpio_ready:
263	gpio_free(RB4XX_NAND_GPIO_READY);
264err:
265	return ret;
266}
267
268static int __devexit rb4xx_nand_remove(struct platform_device *pdev)
269{
270	struct rb4xx_nand_info *info = platform_get_drvdata(pdev);
271
272	nand_release(&info->mtd);
273	platform_set_drvdata(pdev, NULL);
274	kfree(info);
275	gpio_free(RB4XX_NAND_GPIO_NCE);
276	gpio_free(RB4XX_NAND_GPIO_CLE);
277	gpio_free(RB4XX_NAND_GPIO_ALE);
278	gpio_free(RB4XX_NAND_GPIO_READY);
279
280	return 0;
281}
282
283static struct platform_driver rb4xx_nand_driver = {
284	.probe	= rb4xx_nand_probe,
285	.remove	= __devexit_p(rb4xx_nand_remove),
286	.driver	= {
287		.name	= DRV_NAME,
288		.owner	= THIS_MODULE,
289	},
290};
291
292static int __init rb4xx_nand_init(void)
293{
294	return platform_driver_register(&rb4xx_nand_driver);
295}
296
297static void __exit rb4xx_nand_exit(void)
298{
299	platform_driver_unregister(&rb4xx_nand_driver);
300}
301
302module_init(rb4xx_nand_init);
303module_exit(rb4xx_nand_exit);
304
305MODULE_DESCRIPTION(DRV_DESC);
306MODULE_VERSION(DRV_VERSION);
307MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
308MODULE_AUTHOR("Imre Kaloz <kaloz@openwrt.org>");
309MODULE_LICENSE("GPL v2");
310