bfin-async-flash.c revision 10715b8751dfc403aeb7fbc35166417fa1664eda 
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@cam.org>
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/types.h>
26
27#include <asm/blackfin.h>
28#include <linux/gpio.h>
29#include <linux/io.h>
30#include <asm/unaligned.h>
31
32#define pr_devinit(fmt, args...) ({ static const __devinitconst char __fmt[] = fmt; printk(__fmt, ## args); })
33
34#define DRIVER_NAME "bfin-async-flash"
35
36struct async_state {
37	struct mtd_info *mtd;
38	struct map_info map;
39	int enet_flash_pin;
40	uint32_t flash_ambctl0, flash_ambctl1;
41	uint32_t save_ambctl0, save_ambctl1;
42	unsigned long irq_flags;
43};
44
45static void switch_to_flash(struct async_state *state)
46{
47	local_irq_save(state->irq_flags);
48
49	gpio_set_value(state->enet_flash_pin, 0);
50
51	state->save_ambctl0 = bfin_read_EBIU_AMBCTL0();
52	state->save_ambctl1 = bfin_read_EBIU_AMBCTL1();
53	bfin_write_EBIU_AMBCTL0(state->flash_ambctl0);
54	bfin_write_EBIU_AMBCTL1(state->flash_ambctl1);
55	SSYNC();
56}
57
58static void switch_back(struct async_state *state)
59{
60	bfin_write_EBIU_AMBCTL0(state->save_ambctl0);
61	bfin_write_EBIU_AMBCTL1(state->save_ambctl1);
62	SSYNC();
63
64	gpio_set_value(state->enet_flash_pin, 1);
65
66	local_irq_restore(state->irq_flags);
67}
68
69static map_word bfin_read(struct map_info *map, unsigned long ofs)
70{
71	struct async_state *state = (struct async_state *)map->map_priv_1;
72	uint16_t word;
73	map_word test;
74
75	switch_to_flash(state);
76
77	word = readw(map->virt + ofs);
78
79	switch_back(state);
80
81	test.x[0] = word;
82	return test;
83}
84
85static void bfin_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
86{
87	struct async_state *state = (struct async_state *)map->map_priv_1;
88
89	switch_to_flash(state);
90
91	memcpy(to, map->virt + from, len);
92
93	switch_back(state);
94}
95
96static void bfin_write(struct map_info *map, map_word d1, unsigned long ofs)
97{
98	struct async_state *state = (struct async_state *)map->map_priv_1;
99	uint16_t d;
100
101	d = d1.x[0];
102
103	switch_to_flash(state);
104
105	writew(d, map->virt + ofs);
106	SSYNC();
107
108	switch_back(state);
109}
110
111static void bfin_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
112{
113	struct async_state *state = (struct async_state *)map->map_priv_1;
114
115	switch_to_flash(state);
116
117	memcpy(map->virt + to, from, len);
118	SSYNC();
119
120	switch_back(state);
121}
122
123#ifdef CONFIG_MTD_PARTITIONS
124static const char *part_probe_types[] = { "cmdlinepart", "RedBoot", NULL };
125#endif
126
127static int __devinit bfin_flash_probe(struct platform_device *pdev)
128{
129	int ret;
130	struct physmap_flash_data *pdata = pdev->dev.platform_data;
131	struct resource *memory = platform_get_resource(pdev, IORESOURCE_MEM, 0);
132	struct resource *flash_ambctl = platform_get_resource(pdev, IORESOURCE_MEM, 1);
133	struct async_state *state;
134
135	state = kzalloc(sizeof(*state), GFP_KERNEL);
136	if (!state)
137		return -ENOMEM;
138
139	state->map.name       = DRIVER_NAME;
140	state->map.read       = bfin_read;
141	state->map.copy_from  = bfin_copy_from;
142	state->map.write      = bfin_write;
143	state->map.copy_to    = bfin_copy_to;
144	state->map.bankwidth  = pdata->width;
145	state->map.size       = memory->end - memory->start + 1;
146	state->map.virt       = (void __iomem *)memory->start;
147	state->map.phys       = memory->start;
148	state->map.map_priv_1 = (unsigned long)state;
149	state->enet_flash_pin = platform_get_irq(pdev, 0);
150	state->flash_ambctl0  = flash_ambctl->start;
151	state->flash_ambctl1  = flash_ambctl->end;
152
153	if (gpio_request(state->enet_flash_pin, DRIVER_NAME)) {
154		pr_devinit(KERN_ERR DRIVER_NAME ": Failed to request gpio %d\n", state->enet_flash_pin);
155		kfree(state);
156		return -EBUSY;
157	}
158	gpio_direction_output(state->enet_flash_pin, 1);
159
160	pr_devinit(KERN_NOTICE DRIVER_NAME ": probing %d-bit flash bus\n", state->map.bankwidth * 8);
161	state->mtd = do_map_probe(memory->name, &state->map);
162	if (!state->mtd) {
163		gpio_free(state->enet_flash_pin);
164		kfree(state);
165		return -ENXIO;
166	}
167
168#ifdef CONFIG_MTD_PARTITIONS
169	ret = parse_mtd_partitions(state->mtd, part_probe_types, &pdata->parts, 0);
170	if (ret > 0) {
171		pr_devinit(KERN_NOTICE DRIVER_NAME ": Using commandline partition definition\n");
172		add_mtd_partitions(state->mtd, pdata->parts, ret);
173
174	} else if (pdata->nr_parts) {
175		pr_devinit(KERN_NOTICE DRIVER_NAME ": Using board partition definition\n");
176		add_mtd_partitions(state->mtd, pdata->parts, pdata->nr_parts);
177
178	} else
179#endif
180	{
181		pr_devinit(KERN_NOTICE DRIVER_NAME ": no partition info available, registering whole flash at once\n");
182		add_mtd_device(state->mtd);
183	}
184
185	platform_set_drvdata(pdev, state);
186
187	return 0;
188}
189
190static int __devexit bfin_flash_remove(struct platform_device *pdev)
191{
192	struct async_state *state = platform_get_drvdata(pdev);
193	gpio_free(state->enet_flash_pin);
194#ifdef CONFIG_MTD_PARTITIONS
195	del_mtd_partitions(state->mtd);
196#endif
197	map_destroy(state->mtd);
198	kfree(state);
199	return 0;
200}
201
202static struct platform_driver bfin_flash_driver = {
203	.probe		= bfin_flash_probe,
204	.remove		= __devexit_p(bfin_flash_remove),
205	.driver		= {
206		.name	= DRIVER_NAME,
207	},
208};
209
210static int __init bfin_flash_init(void)
211{
212	return platform_driver_register(&bfin_flash_driver);
213}
214module_init(bfin_flash_init);
215
216static void __exit bfin_flash_exit(void)
217{
218	platform_driver_unregister(&bfin_flash_driver);
219}
220module_exit(bfin_flash_exit);
221
222MODULE_LICENSE("GPL");
223MODULE_DESCRIPTION("MTD map driver for Blackfins with flash/ethernet on same async bank");
224