bfin-async-flash.c revision 5a0e3ad6af8660be21ca98a971cd00f331318c05 
1/*
2 * drivers/mtd/maps/bfin-async-flash.c
3 *
4 * Handle the case where flash memory and ethernet mac/phy are
5 * mapped onto the same async bank.  The BF533-STAMP does this
6 * for example.  All board-specific configuration goes in your
7 * board resources file.
8 *
9 * Copyright 2000 Nicolas Pitre <nico@fluxnic.net>
10 * Copyright 2005-2008 Analog Devices Inc.
11 *
12 * Enter bugs at http://blackfin.uclinux.org/
13 *
14 * Licensed under the GPL-2 or later.
15 */
16
17#include <linux/init.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/mtd/mtd.h>
21#include <linux/mtd/map.h>
22#include <linux/mtd/partitions.h>
23#include <linux/mtd/physmap.h>
24#include <linux/platform_device.h>
25#include <linux/slab.h>
26#include <linux/types.h>
27
28#include <asm/blackfin.h>
29#include <linux/gpio.h>
30#include <linux/io.h>
31#include <asm/unaligned.h>
32
33#define pr_devinit(fmt, args...) ({ static const __devinitconst char __fmt[] = fmt; printk(__fmt, ## args); })
34
35#define DRIVER_NAME "bfin-async-flash"
36
37struct async_state {
38	struct mtd_info *mtd;
39	struct map_info map;
40	int enet_flash_pin;
41	uint32_t flash_ambctl0, flash_ambctl1;
42	uint32_t save_ambctl0, save_ambctl1;
43	unsigned long irq_flags;
44#ifdef CONFIG_MTD_PARTITIONS
45	struct mtd_partition *parts;
46#endif
47};
48
49static void switch_to_flash(struct async_state *state)
50{
51	local_irq_save(state->irq_flags);
52
53	gpio_set_value(state->enet_flash_pin, 0);
54
55	state->save_ambctl0 = bfin_read_EBIU_AMBCTL0();
56	state->save_ambctl1 = bfin_read_EBIU_AMBCTL1();
57	bfin_write_EBIU_AMBCTL0(state->flash_ambctl0);
58	bfin_write_EBIU_AMBCTL1(state->flash_ambctl1);
59	SSYNC();
60}
61
62static void switch_back(struct async_state *state)
63{
64	bfin_write_EBIU_AMBCTL0(state->save_ambctl0);
65	bfin_write_EBIU_AMBCTL1(state->save_ambctl1);
66	SSYNC();
67
68	gpio_set_value(state->enet_flash_pin, 1);
69
70	local_irq_restore(state->irq_flags);
71}
72
73static map_word bfin_read(struct map_info *map, unsigned long ofs)
74{
75	struct async_state *state = (struct async_state *)map->map_priv_1;
76	uint16_t word;
77	map_word test;
78
79	switch_to_flash(state);
80
81	word = readw(map->virt + ofs);
82
83	switch_back(state);
84
85	test.x[0] = word;
86	return test;
87}
88
89static void bfin_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
90{
91	struct async_state *state = (struct async_state *)map->map_priv_1;
92
93	switch_to_flash(state);
94
95	memcpy(to, map->virt + from, len);
96
97	switch_back(state);
98}
99
100static void bfin_write(struct map_info *map, map_word d1, unsigned long ofs)
101{
102	struct async_state *state = (struct async_state *)map->map_priv_1;
103	uint16_t d;
104
105	d = d1.x[0];
106
107	switch_to_flash(state);
108
109	writew(d, map->virt + ofs);
110	SSYNC();
111
112	switch_back(state);
113}
114
115static void bfin_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
116{
117	struct async_state *state = (struct async_state *)map->map_priv_1;
118
119	switch_to_flash(state);
120
121	memcpy(map->virt + to, from, len);
122	SSYNC();
123
124	switch_back(state);
125}
126
127#ifdef CONFIG_MTD_PARTITIONS
128static const char *part_probe_types[] = { "cmdlinepart", "RedBoot", NULL };
129#endif
130
131static int __devinit bfin_flash_probe(struct platform_device *pdev)
132{
133	int ret;
134	struct physmap_flash_data *pdata = pdev->dev.platform_data;
135	struct resource *memory = platform_get_resource(pdev, IORESOURCE_MEM, 0);
136	struct resource *flash_ambctl = platform_get_resource(pdev, IORESOURCE_MEM, 1);
137	struct async_state *state;
138
139	state = kzalloc(sizeof(*state), GFP_KERNEL);
140	if (!state)
141		return -ENOMEM;
142
143	state->map.name       = DRIVER_NAME;
144	state->map.read       = bfin_read;
145	state->map.copy_from  = bfin_copy_from;
146	state->map.write      = bfin_write;
147	state->map.copy_to    = bfin_copy_to;
148	state->map.bankwidth  = pdata->width;
149	state->map.size       = memory->end - memory->start + 1;
150	state->map.virt       = (void __iomem *)memory->start;
151	state->map.phys       = memory->start;
152	state->map.map_priv_1 = (unsigned long)state;
153	state->enet_flash_pin = platform_get_irq(pdev, 0);
154	state->flash_ambctl0  = flash_ambctl->start;
155	state->flash_ambctl1  = flash_ambctl->end;
156
157	if (gpio_request(state->enet_flash_pin, DRIVER_NAME)) {
158		pr_devinit(KERN_ERR DRIVER_NAME ": Failed to request gpio %d\n", state->enet_flash_pin);
159		kfree(state);
160		return -EBUSY;
161	}
162	gpio_direction_output(state->enet_flash_pin, 1);
163
164	pr_devinit(KERN_NOTICE DRIVER_NAME ": probing %d-bit flash bus\n", state->map.bankwidth * 8);
165	state->mtd = do_map_probe(memory->name, &state->map);
166	if (!state->mtd) {
167		gpio_free(state->enet_flash_pin);
168		kfree(state);
169		return -ENXIO;
170	}
171
172#ifdef CONFIG_MTD_PARTITIONS
173	ret = parse_mtd_partitions(state->mtd, part_probe_types, &pdata->parts, 0);
174	if (ret > 0) {
175		pr_devinit(KERN_NOTICE DRIVER_NAME ": Using commandline partition definition\n");
176		add_mtd_partitions(state->mtd, pdata->parts, ret);
177		state->parts = pdata->parts;
178
179	} else if (pdata->nr_parts) {
180		pr_devinit(KERN_NOTICE DRIVER_NAME ": Using board partition definition\n");
181		add_mtd_partitions(state->mtd, pdata->parts, pdata->nr_parts);
182
183	} else
184#endif
185	{
186		pr_devinit(KERN_NOTICE DRIVER_NAME ": no partition info available, registering whole flash at once\n");
187		add_mtd_device(state->mtd);
188	}
189
190	platform_set_drvdata(pdev, state);
191
192	return 0;
193}
194
195static int __devexit bfin_flash_remove(struct platform_device *pdev)
196{
197	struct async_state *state = platform_get_drvdata(pdev);
198	gpio_free(state->enet_flash_pin);
199#ifdef CONFIG_MTD_PARTITIONS
200	del_mtd_partitions(state->mtd);
201	kfree(state->parts);
202#endif
203	map_destroy(state->mtd);
204	kfree(state);
205	return 0;
206}
207
208static struct platform_driver bfin_flash_driver = {
209	.probe		= bfin_flash_probe,
210	.remove		= __devexit_p(bfin_flash_remove),
211	.driver		= {
212		.name	= DRIVER_NAME,
213	},
214};
215
216static int __init bfin_flash_init(void)
217{
218	return platform_driver_register(&bfin_flash_driver);
219}
220module_init(bfin_flash_init);
221
222static void __exit bfin_flash_exit(void)
223{
224	platform_driver_unregister(&bfin_flash_driver);
225}
226module_exit(bfin_flash_exit);
227
228MODULE_LICENSE("GPL");
229MODULE_DESCRIPTION("MTD map driver for Blackfins with flash/ethernet on same async bank");
230