Root/target/linux/lantiq/patches-2.6.32/0004-MIPS-Lantiq-Add-NOR-flash-support.patch

1From cd0d53b24ca744295d2cdf69bb2b659571091b75 Mon Sep 17 00:00:00 2001
2From: John Crispin <blogic@openwrt.org>
3Date: Tue, 12 Apr 2011 18:10:01 +0200
4Subject: [PATCH 04/13] MIPS: Lantiq: Add NOR flash support
5
6This patch adds the driver/map for NOR devices attached to the SoC via the
7External Bus Unit (EBU).
8
9Signed-off-by: John Crispin <blogic@openwrt.org>
10Signed-off-by: Ralph Hempel <ralph.hempel@lantiq.com>
11Cc: David Woodhouse <dwmw2@infradead.org>
12Cc: Daniel Schwierzeck <daniel.schwierzeck@googlemail.com>
13Cc: linux-mips@linux-mips.org
14Cc: linux-mtd@lists.infradead.org
15Acked-by: Artem Bityutskiy <dedekind1@gmail.com>
16Patchwork: https://patchwork.linux-mips.org/patch/2285/
17Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
18---
19 drivers/mtd/maps/Kconfig | 7 +
20 drivers/mtd/maps/Makefile | 1 +
21 drivers/mtd/maps/lantiq-flash.c | 251 +++++++++++++++++++++++++++++++++++++++
22 3 files changed, 259 insertions(+), 0 deletions(-)
23 create mode 100644 drivers/mtd/maps/lantiq-flash.c
24
25--- a/drivers/mtd/maps/Kconfig
26+++ b/drivers/mtd/maps/Kconfig
27@@ -259,6 +259,13 @@
28     help
29       Flash memory access on AMD Alchemy Pb/Db/RDK Reference Boards
30 
31+config MTD_LANTIQ
32+ tristate "Lantiq SoC NOR support"
33+ depends on LANTIQ
34+ select MTD_PARTITIONS
35+ help
36+ Support for NOR flash attached to the Lantiq SoC's External Bus Unit.
37+
38 config MTD_DILNETPC
39     tristate "CFI Flash device mapped on DIL/Net PC"
40     depends on X86 && MTD_CONCAT && MTD_PARTITIONS && MTD_CFI_INTELEXT && BROKEN
41--- a/drivers/mtd/maps/Makefile
42+++ b/drivers/mtd/maps/Makefile
43@@ -61,3 +61,4 @@
44 obj-$(CONFIG_MTD_RBTX4939) += rbtx4939-flash.o
45 obj-$(CONFIG_MTD_VMU) += vmu-flash.o
46 obj-$(CONFIG_MTD_GPIO_ADDR) += gpio-addr-flash.o
47+obj-$(CONFIG_MTD_LANTIQ) += lantiq-flash.o
48--- /dev/null
49+++ b/drivers/mtd/maps/lantiq-flash.c
50@@ -0,0 +1,251 @@
51+/*
52+ * This program is free software; you can redistribute it and/or modify it
53+ * under the terms of the GNU General Public License version 2 as published
54+ * by the Free Software Foundation.
55+ *
56+ * Copyright (C) 2004 Liu Peng Infineon IFAP DC COM CPE
57+ * Copyright (C) 2010 John Crispin <blogic@openwrt.org>
58+ */
59+
60+#include <linux/module.h>
61+#include <linux/types.h>
62+#include <linux/kernel.h>
63+#include <linux/io.h>
64+#include <linux/slab.h>
65+#include <linux/init.h>
66+#include <linux/mtd/mtd.h>
67+#include <linux/mtd/map.h>
68+#include <linux/mtd/partitions.h>
69+#include <linux/mtd/cfi.h>
70+#include <linux/platform_device.h>
71+#include <linux/mtd/physmap.h>
72+
73+#include <lantiq_soc.h>
74+#include <lantiq_platform.h>
75+
76+/*
77+ * The NOR flash is connected to the same external bus unit (EBU) as PCI.
78+ * To make PCI work we need to enable the endianness swapping for the address
79+ * written to the EBU. This endianness swapping works for PCI correctly but
80+ * fails for attached NOR devices. To workaround this we need to use a complex
81+ * map. The workaround involves swapping all addresses whilst probing the chip.
82+ * Once probing is complete we stop swapping the addresses but swizzle the
83+ * unlock addresses to ensure that access to the NOR device works correctly.
84+ */
85+
86+enum {
87+ LTQ_NOR_PROBING,
88+ LTQ_NOR_NORMAL
89+};
90+
91+struct ltq_mtd {
92+ struct resource *res;
93+ struct mtd_info *mtd;
94+ struct map_info *map;
95+};
96+
97+static char ltq_map_name[] = "ltq_nor";
98+
99+static map_word
100+ltq_read16(struct map_info *map, unsigned long adr)
101+{
102+ unsigned long flags;
103+ map_word temp;
104+
105+ if (map->map_priv_1 == LTQ_NOR_PROBING)
106+ adr ^= 2;
107+ spin_lock_irqsave(&ebu_lock, flags);
108+ temp.x[0] = *(u16 *)(map->virt + adr);
109+ spin_unlock_irqrestore(&ebu_lock, flags);
110+ return temp;
111+}
112+
113+static void
114+ltq_write16(struct map_info *map, map_word d, unsigned long adr)
115+{
116+ unsigned long flags;
117+
118+ if (map->map_priv_1 == LTQ_NOR_PROBING)
119+ adr ^= 2;
120+ spin_lock_irqsave(&ebu_lock, flags);
121+ *(u16 *)(map->virt + adr) = d.x[0];
122+ spin_unlock_irqrestore(&ebu_lock, flags);
123+}
124+
125+/*
126+ * The following 2 functions copy data between iomem and a cached memory
127+ * section. As memcpy() makes use of pre-fetching we cannot use it here.
128+ * The normal alternative of using memcpy_{to,from}io also makes use of
129+ * memcpy() on MIPS so it is not applicable either. We are therefore stuck
130+ * with having to use our own loop.
131+ */
132+static void
133+ltq_copy_from(struct map_info *map, void *to,
134+ unsigned long from, ssize_t len)
135+{
136+ unsigned char *f = (unsigned char *)map->virt + from;
137+ unsigned char *t = (unsigned char *)to;
138+ unsigned long flags;
139+
140+ spin_lock_irqsave(&ebu_lock, flags);
141+ while (len--)
142+ *t++ = *f++;
143+ spin_unlock_irqrestore(&ebu_lock, flags);
144+}
145+
146+static void
147+ltq_copy_to(struct map_info *map, unsigned long to,
148+ const void *from, ssize_t len)
149+{
150+ unsigned char *f = (unsigned char *)from;
151+ unsigned char *t = (unsigned char *)map->virt + to;
152+ unsigned long flags;
153+
154+ spin_lock_irqsave(&ebu_lock, flags);
155+ while (len--)
156+ *t++ = *f++;
157+ spin_unlock_irqrestore(&ebu_lock, flags);
158+}
159+
160+static const char const *part_probe_types[] = { "cmdlinepart", NULL };
161+
162+static int __init
163+ltq_mtd_probe(struct platform_device *pdev)
164+{
165+ struct physmap_flash_data *ltq_mtd_data = dev_get_platdata(&pdev->dev);
166+ struct ltq_mtd *ltq_mtd;
167+ struct mtd_partition *parts;
168+ struct resource *res;
169+ int nr_parts = 0;
170+ struct cfi_private *cfi;
171+ int err;
172+
173+ ltq_mtd = kzalloc(sizeof(struct ltq_mtd), GFP_KERNEL);
174+ platform_set_drvdata(pdev, ltq_mtd);
175+
176+ ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
177+ if (!ltq_mtd->res) {
178+ dev_err(&pdev->dev, "failed to get memory resource");
179+ err = -ENOENT;
180+ goto err_out;
181+ }
182+
183+ res = devm_request_mem_region(&pdev->dev, ltq_mtd->res->start,
184+ resource_size(ltq_mtd->res), dev_name(&pdev->dev));
185+ if (!ltq_mtd->res) {
186+ dev_err(&pdev->dev, "failed to request mem resource");
187+ err = -EBUSY;
188+ goto err_out;
189+ }
190+
191+ ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL);
192+ ltq_mtd->map->phys = res->start;
193+ ltq_mtd->map->size = resource_size(res);
194+ ltq_mtd->map->virt = devm_ioremap_nocache(&pdev->dev,
195+ ltq_mtd->map->phys, ltq_mtd->map->size);
196+ if (!ltq_mtd->map->virt) {
197+ dev_err(&pdev->dev, "failed to ioremap!\n");
198+ err = -ENOMEM;
199+ goto err_free;
200+ }
201+
202+ ltq_mtd->map->name = ltq_map_name;
203+ ltq_mtd->map->bankwidth = 2;
204+ ltq_mtd->map->read = ltq_read16;
205+ ltq_mtd->map->write = ltq_write16;
206+ ltq_mtd->map->copy_from = ltq_copy_from;
207+ ltq_mtd->map->copy_to = ltq_copy_to;
208+
209+ ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
210+ ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map);
211+ ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;
212+
213+ if (!ltq_mtd->mtd) {
214+ dev_err(&pdev->dev, "probing failed\n");
215+ err = -ENXIO;
216+ goto err_unmap;
217+ }
218+
219+ ltq_mtd->mtd->owner = THIS_MODULE;
220+
221+ cfi = ltq_mtd->map->fldrv_priv;
222+ cfi->addr_unlock1 ^= 1;
223+ cfi->addr_unlock2 ^= 1;
224+
225+ nr_parts = parse_mtd_partitions(ltq_mtd->mtd,
226+ part_probe_types, &parts, 0);
227+ if (nr_parts > 0) {
228+ dev_info(&pdev->dev,
229+ "using %d partitions from cmdline", nr_parts);
230+ } else {
231+ nr_parts = ltq_mtd_data->nr_parts;
232+ parts = ltq_mtd_data->parts;
233+ }
234+
235+ err = add_mtd_partitions(ltq_mtd->mtd, parts, nr_parts);
236+ if (err) {
237+ dev_err(&pdev->dev, "failed to add partitions\n");
238+ goto err_destroy;
239+ }
240+
241+ return 0;
242+
243+err_destroy:
244+ map_destroy(ltq_mtd->mtd);
245+err_unmap:
246+ iounmap(ltq_mtd->map->virt);
247+err_free:
248+ kfree(ltq_mtd->map);
249+err_out:
250+ kfree(ltq_mtd);
251+ return err;
252+}
253+
254+static int __devexit
255+ltq_mtd_remove(struct platform_device *pdev)
256+{
257+ struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);
258+
259+ if (ltq_mtd) {
260+ if (ltq_mtd->mtd) {
261+ del_mtd_partitions(ltq_mtd->mtd);
262+ map_destroy(ltq_mtd->mtd);
263+ }
264+ if (ltq_mtd->map->virt)
265+ iounmap(ltq_mtd->map->virt);
266+ kfree(ltq_mtd->map);
267+ kfree(ltq_mtd);
268+ }
269+ return 0;
270+}
271+
272+static struct platform_driver ltq_mtd_driver = {
273+ .remove = __devexit_p(ltq_mtd_remove),
274+ .driver = {
275+ .name = "ltq_nor",
276+ .owner = THIS_MODULE,
277+ },
278+};
279+
280+static int __init
281+init_ltq_mtd(void)
282+{
283+ int ret = platform_driver_probe(&ltq_mtd_driver, ltq_mtd_probe);
284+
285+ if (ret)
286+ pr_err("ltq_nor: error registering platform driver");
287+ return ret;
288+}
289+
290+static void __exit
291+exit_ltq_mtd(void)
292+{
293+ platform_driver_unregister(&ltq_mtd_driver);
294+}
295+
296+module_init(init_ltq_mtd);
297+module_exit(exit_ltq_mtd);
298+
299+MODULE_LICENSE("GPL");
300+MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
301+MODULE_DESCRIPTION("Lantiq SoC NOR");
302

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