1/*
2 *  Overview:
3 *   Platform independent driver for NDFC (NanD Flash Controller)
4 *   integrated into EP440 cores
5 *
6 *   Ported to an OF platform driver by Sean MacLennan
7 *
8 *   The NDFC supports multiple chips, but this driver only supports a
9 *   single chip since I do not have access to any boards with
10 *   multiple chips.
11 *
12 *  Author: Thomas Gleixner
13 *
14 *  Copyright 2006 IBM
15 *  Copyright 2008 PIKA Technologies
16 *    Sean MacLennan <smaclennan@pikatech.com>
17 *
18 *  This program is free software; you can redistribute	 it and/or modify it
19 *  under  the terms of	 the GNU General  Public License as published by the
20 *  Free Software Foundation;  either version 2 of the	License, or (at your
21 *  option) any later version.
22 *
23 */
24#include <linux/module.h>
25#include <linux/mtd/nand.h>
26#include <linux/mtd/nand_ecc.h>
27#include <linux/mtd/partitions.h>
28#include <linux/mtd/ndfc.h>
29#include <linux/slab.h>
30#include <linux/mtd/mtd.h>
31#include <linux/of_address.h>
32#include <linux/of_platform.h>
33#include <asm/io.h>
34
35#define NDFC_MAX_CS    4
36
37struct ndfc_controller {
38	struct platform_device *ofdev;
39	void __iomem *ndfcbase;
40	struct mtd_info mtd;
41	struct nand_chip chip;
42	int chip_select;
43	struct nand_hw_control ndfc_control;
44};
45
46static struct ndfc_controller ndfc_ctrl[NDFC_MAX_CS];
47
48static void ndfc_select_chip(struct mtd_info *mtd, int chip)
49{
50	uint32_t ccr;
51	struct nand_chip *nchip = mtd->priv;
52	struct ndfc_controller *ndfc = nchip->priv;
53
54	ccr = in_be32(ndfc->ndfcbase + NDFC_CCR);
55	if (chip >= 0) {
56		ccr &= ~NDFC_CCR_BS_MASK;
57		ccr |= NDFC_CCR_BS(chip + ndfc->chip_select);
58	} else
59		ccr |= NDFC_CCR_RESET_CE;
60	out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
61}
62
63static void ndfc_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
64{
65	struct nand_chip *chip = mtd->priv;
66	struct ndfc_controller *ndfc = chip->priv;
67
68	if (cmd == NAND_CMD_NONE)
69		return;
70
71	if (ctrl & NAND_CLE)
72		writel(cmd & 0xFF, ndfc->ndfcbase + NDFC_CMD);
73	else
74		writel(cmd & 0xFF, ndfc->ndfcbase + NDFC_ALE);
75}
76
77static int ndfc_ready(struct mtd_info *mtd)
78{
79	struct nand_chip *chip = mtd->priv;
80	struct ndfc_controller *ndfc = chip->priv;
81
82	return in_be32(ndfc->ndfcbase + NDFC_STAT) & NDFC_STAT_IS_READY;
83}
84
85static void ndfc_enable_hwecc(struct mtd_info *mtd, int mode)
86{
87	uint32_t ccr;
88	struct nand_chip *chip = mtd->priv;
89	struct ndfc_controller *ndfc = chip->priv;
90
91	ccr = in_be32(ndfc->ndfcbase + NDFC_CCR);
92	ccr |= NDFC_CCR_RESET_ECC;
93	out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
94	wmb();
95}
96
97static int ndfc_calculate_ecc(struct mtd_info *mtd,
98			      const u_char *dat, u_char *ecc_code)
99{
100	struct nand_chip *chip = mtd->priv;
101	struct ndfc_controller *ndfc = chip->priv;
102	uint32_t ecc;
103	uint8_t *p = (uint8_t *)&ecc;
104
105	wmb();
106	ecc = in_be32(ndfc->ndfcbase + NDFC_ECC);
107	/* The NDFC uses Smart Media (SMC) bytes order */
108	ecc_code[0] = p[1];
109	ecc_code[1] = p[2];
110	ecc_code[2] = p[3];
111
112	return 0;
113}
114
115/*
116 * Speedups for buffer read/write/verify
117 *
118 * NDFC allows 32bit read/write of data. So we can speed up the buffer
119 * functions. No further checking, as nand_base will always read/write
120 * page aligned.
121 */
122static void ndfc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
123{
124	struct nand_chip *chip = mtd->priv;
125	struct ndfc_controller *ndfc = chip->priv;
126	uint32_t *p = (uint32_t *) buf;
127
128	for(;len > 0; len -= 4)
129		*p++ = in_be32(ndfc->ndfcbase + NDFC_DATA);
130}
131
132static void ndfc_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
133{
134	struct nand_chip *chip = mtd->priv;
135	struct ndfc_controller *ndfc = chip->priv;
136	uint32_t *p = (uint32_t *) buf;
137
138	for(;len > 0; len -= 4)
139		out_be32(ndfc->ndfcbase + NDFC_DATA, *p++);
140}
141
142/*
143 * Initialize chip structure
144 */
145static int ndfc_chip_init(struct ndfc_controller *ndfc,
146			  struct device_node *node)
147{
148	struct device_node *flash_np;
149	struct nand_chip *chip = &ndfc->chip;
150	struct mtd_part_parser_data ppdata;
151	int ret;
152
153	chip->IO_ADDR_R = ndfc->ndfcbase + NDFC_DATA;
154	chip->IO_ADDR_W = ndfc->ndfcbase + NDFC_DATA;
155	chip->cmd_ctrl = ndfc_hwcontrol;
156	chip->dev_ready = ndfc_ready;
157	chip->select_chip = ndfc_select_chip;
158	chip->chip_delay = 50;
159	chip->controller = &ndfc->ndfc_control;
160	chip->read_buf = ndfc_read_buf;
161	chip->write_buf = ndfc_write_buf;
162	chip->ecc.correct = nand_correct_data;
163	chip->ecc.hwctl = ndfc_enable_hwecc;
164	chip->ecc.calculate = ndfc_calculate_ecc;
165	chip->ecc.mode = NAND_ECC_HW;
166	chip->ecc.size = 256;
167	chip->ecc.bytes = 3;
168	chip->ecc.strength = 1;
169	chip->priv = ndfc;
170
171	ndfc->mtd.priv = chip;
172	ndfc->mtd.dev.parent = &ndfc->ofdev->dev;
173
174	flash_np = of_get_next_child(node, NULL);
175	if (!flash_np)
176		return -ENODEV;
177
178	ppdata.of_node = flash_np;
179	ndfc->mtd.name = kasprintf(GFP_KERNEL, "%s.%s",
180			dev_name(&ndfc->ofdev->dev), flash_np->name);
181	if (!ndfc->mtd.name) {
182		ret = -ENOMEM;
183		goto err;
184	}
185
186	ret = nand_scan(&ndfc->mtd, 1);
187	if (ret)
188		goto err;
189
190	ret = mtd_device_parse_register(&ndfc->mtd, NULL, &ppdata, NULL, 0);
191
192err:
193	of_node_put(flash_np);
194	if (ret)
195		kfree(ndfc->mtd.name);
196	return ret;
197}
198
199static int ndfc_probe(struct platform_device *ofdev)
200{
201	struct ndfc_controller *ndfc;
202	const __be32 *reg;
203	u32 ccr;
204	u32 cs;
205	int err, len;
206
207	/* Read the reg property to get the chip select */
208	reg = of_get_property(ofdev->dev.of_node, "reg", &len);
209	if (reg == NULL || len != 12) {
210		dev_err(&ofdev->dev, "unable read reg property (%d)\n", len);
211		return -ENOENT;
212	}
213
214	cs = be32_to_cpu(reg[0]);
215	if (cs >= NDFC_MAX_CS) {
216		dev_err(&ofdev->dev, "invalid CS number (%d)\n", cs);
217		return -EINVAL;
218	}
219
220	ndfc = &ndfc_ctrl[cs];
221	ndfc->chip_select = cs;
222
223	spin_lock_init(&ndfc->ndfc_control.lock);
224	init_waitqueue_head(&ndfc->ndfc_control.wq);
225	ndfc->ofdev = ofdev;
226	dev_set_drvdata(&ofdev->dev, ndfc);
227
228	ndfc->ndfcbase = of_iomap(ofdev->dev.of_node, 0);
229	if (!ndfc->ndfcbase) {
230		dev_err(&ofdev->dev, "failed to get memory\n");
231		return -EIO;
232	}
233
234	ccr = NDFC_CCR_BS(ndfc->chip_select);
235
236	/* It is ok if ccr does not exist - just default to 0 */
237	reg = of_get_property(ofdev->dev.of_node, "ccr", NULL);
238	if (reg)
239		ccr |= be32_to_cpup(reg);
240
241	out_be32(ndfc->ndfcbase + NDFC_CCR, ccr);
242
243	/* Set the bank settings if given */
244	reg = of_get_property(ofdev->dev.of_node, "bank-settings", NULL);
245	if (reg) {
246		int offset = NDFC_BCFG0 + (ndfc->chip_select << 2);
247		out_be32(ndfc->ndfcbase + offset, be32_to_cpup(reg));
248	}
249
250	err = ndfc_chip_init(ndfc, ofdev->dev.of_node);
251	if (err) {
252		iounmap(ndfc->ndfcbase);
253		return err;
254	}
255
256	return 0;
257}
258
259static int ndfc_remove(struct platform_device *ofdev)
260{
261	struct ndfc_controller *ndfc = dev_get_drvdata(&ofdev->dev);
262
263	nand_release(&ndfc->mtd);
264	kfree(ndfc->mtd.name);
265
266	return 0;
267}
268
269static const struct of_device_id ndfc_match[] = {
270	{ .compatible = "ibm,ndfc", },
271	{}
272};
273MODULE_DEVICE_TABLE(of, ndfc_match);
274
275static struct platform_driver ndfc_driver = {
276	.driver = {
277		.name = "ndfc",
278		.of_match_table = ndfc_match,
279	},
280	.probe = ndfc_probe,
281	.remove = ndfc_remove,
282};
283
284module_platform_driver(ndfc_driver);
285
286MODULE_LICENSE("GPL");
287MODULE_AUTHOR("Thomas Gleixner <tglx@linutronix.de>");
288MODULE_DESCRIPTION("OF Platform driver for NDFC");
289