bfin-async-flash.c revision 810b7e060c14110d8f580daaf77fab3a7d950483 
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 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};
45
46static void switch_to_flash(struct async_state *state)
47{
48	local_irq_save(state->irq_flags);
49
50	gpio_set_value(state->enet_flash_pin, 0);
51
52	state->save_ambctl0 = bfin_read_EBIU_AMBCTL0();
53	state->save_ambctl1 = bfin_read_EBIU_AMBCTL1();
54	bfin_write_EBIU_AMBCTL0(state->flash_ambctl0);
55	bfin_write_EBIU_AMBCTL1(state->flash_ambctl1);
56	SSYNC();
57}
58
59static void switch_back(struct async_state *state)
60{
61	bfin_write_EBIU_AMBCTL0(state->save_ambctl0);
62	bfin_write_EBIU_AMBCTL1(state->save_ambctl1);
63	SSYNC();
64
65	gpio_set_value(state->enet_flash_pin, 1);
66
67	local_irq_restore(state->irq_flags);
68}
69
70static map_word bfin_flash_read(struct map_info *map, unsigned long ofs)
71{
72	struct async_state *state = (struct async_state *)map->map_priv_1;
73	uint16_t word;
74	map_word test;
75
76	switch_to_flash(state);
77
78	word = readw(map->virt + ofs);
79
80	switch_back(state);
81
82	test.x[0] = word;
83	return test;
84}
85
86static void bfin_flash_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
87{
88	struct async_state *state = (struct async_state *)map->map_priv_1;
89
90	switch_to_flash(state);
91
92	memcpy(to, map->virt + from, len);
93
94	switch_back(state);
95}
96
97static void bfin_flash_write(struct map_info *map, map_word d1, unsigned long ofs)
98{
99	struct async_state *state = (struct async_state *)map->map_priv_1;
100	uint16_t d;
101
102	d = d1.x[0];
103
104	switch_to_flash(state);
105
106	writew(d, map->virt + ofs);
107	SSYNC();
108
109	switch_back(state);
110}
111
112static void bfin_flash_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
113{
114	struct async_state *state = (struct async_state *)map->map_priv_1;
115
116	switch_to_flash(state);
117
118	memcpy(map->virt + to, from, len);
119	SSYNC();
120
121	switch_back(state);
122}
123
124static const char *part_probe_types[] = { "cmdlinepart", "RedBoot", NULL };
125
126static int bfin_flash_probe(struct platform_device *pdev)
127{
128	int ret;
129	struct physmap_flash_data *pdata = pdev->dev.platform_data;
130	struct resource *memory = platform_get_resource(pdev, IORESOURCE_MEM, 0);
131	struct resource *flash_ambctl = platform_get_resource(pdev, IORESOURCE_MEM, 1);
132	struct async_state *state;
133
134	state = kzalloc(sizeof(*state), GFP_KERNEL);
135	if (!state)
136		return -ENOMEM;
137
138	state->map.name       = DRIVER_NAME;
139	state->map.read       = bfin_flash_read;
140	state->map.copy_from  = bfin_flash_copy_from;
141	state->map.write      = bfin_flash_write;
142	state->map.copy_to    = bfin_flash_copy_to;
143	state->map.bankwidth  = pdata->width;
144	state->map.size       = resource_size(memory);
145	state->map.virt       = (void __iomem *)memory->start;
146	state->map.phys       = memory->start;
147	state->map.map_priv_1 = (unsigned long)state;
148	state->enet_flash_pin = platform_get_irq(pdev, 0);
149	state->flash_ambctl0  = flash_ambctl->start;
150	state->flash_ambctl1  = flash_ambctl->end;
151
152	if (gpio_request(state->enet_flash_pin, DRIVER_NAME)) {
153		pr_devinit(KERN_ERR DRIVER_NAME ": Failed to request gpio %d\n", state->enet_flash_pin);
154		kfree(state);
155		return -EBUSY;
156	}
157	gpio_direction_output(state->enet_flash_pin, 1);
158
159	pr_devinit(KERN_NOTICE DRIVER_NAME ": probing %d-bit flash bus\n", state->map.bankwidth * 8);
160	state->mtd = do_map_probe(memory->name, &state->map);
161	if (!state->mtd) {
162		gpio_free(state->enet_flash_pin);
163		kfree(state);
164		return -ENXIO;
165	}
166
167	mtd_device_parse_register(state->mtd, part_probe_types, NULL,
168				  pdata->parts, pdata->nr_parts);
169
170	platform_set_drvdata(pdev, state);
171
172	return 0;
173}
174
175static int bfin_flash_remove(struct platform_device *pdev)
176{
177	struct async_state *state = platform_get_drvdata(pdev);
178	gpio_free(state->enet_flash_pin);
179	mtd_device_unregister(state->mtd);
180	map_destroy(state->mtd);
181	kfree(state);
182	return 0;
183}
184
185static struct platform_driver bfin_flash_driver = {
186	.probe		= bfin_flash_probe,
187	.remove		= bfin_flash_remove,
188	.driver		= {
189		.name	= DRIVER_NAME,
190	},
191};
192
193module_platform_driver(bfin_flash_driver);
194
195MODULE_LICENSE("GPL");
196MODULE_DESCRIPTION("MTD map driver for Blackfins with flash/ethernet on same async bank");
197