bfin-async-flash.c revision d20d5a5780a014bc4d24dbcb6daf7673a9dddf98 
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...) \
34		({ static const char __fmt[] = fmt; printk(__fmt, ## args); })
35
36#define DRIVER_NAME "bfin-async-flash"
37
38struct async_state {
39	struct mtd_info *mtd;
40	struct map_info map;
41	int enet_flash_pin;
42	uint32_t flash_ambctl0, flash_ambctl1;
43	uint32_t save_ambctl0, save_ambctl1;
44	unsigned long irq_flags;
45};
46
47static void switch_to_flash(struct async_state *state)
48{
49	local_irq_save(state->irq_flags);
50
51	gpio_set_value(state->enet_flash_pin, 0);
52
53	state->save_ambctl0 = bfin_read_EBIU_AMBCTL0();
54	state->save_ambctl1 = bfin_read_EBIU_AMBCTL1();
55	bfin_write_EBIU_AMBCTL0(state->flash_ambctl0);
56	bfin_write_EBIU_AMBCTL1(state->flash_ambctl1);
57	SSYNC();
58}
59
60static void switch_back(struct async_state *state)
61{
62	bfin_write_EBIU_AMBCTL0(state->save_ambctl0);
63	bfin_write_EBIU_AMBCTL1(state->save_ambctl1);
64	SSYNC();
65
66	gpio_set_value(state->enet_flash_pin, 1);
67
68	local_irq_restore(state->irq_flags);
69}
70
71static map_word bfin_flash_read(struct map_info *map, unsigned long ofs)
72{
73	struct async_state *state = (struct async_state *)map->map_priv_1;
74	uint16_t word;
75	map_word test;
76
77	switch_to_flash(state);
78
79	word = readw(map->virt + ofs);
80
81	switch_back(state);
82
83	test.x[0] = word;
84	return test;
85}
86
87static void bfin_flash_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
88{
89	struct async_state *state = (struct async_state *)map->map_priv_1;
90
91	switch_to_flash(state);
92
93	memcpy(to, map->virt + from, len);
94
95	switch_back(state);
96}
97
98static void bfin_flash_write(struct map_info *map, map_word d1, unsigned long ofs)
99{
100	struct async_state *state = (struct async_state *)map->map_priv_1;
101	uint16_t d;
102
103	d = d1.x[0];
104
105	switch_to_flash(state);
106
107	writew(d, map->virt + ofs);
108	SSYNC();
109
110	switch_back(state);
111}
112
113static void bfin_flash_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
114{
115	struct async_state *state = (struct async_state *)map->map_priv_1;
116
117	switch_to_flash(state);
118
119	memcpy(map->virt + to, from, len);
120	SSYNC();
121
122	switch_back(state);
123}
124
125static const char * const part_probe_types[] = {
126	"cmdlinepart", "RedBoot", NULL };
127
128static int bfin_flash_probe(struct platform_device *pdev)
129{
130	int ret;
131	struct physmap_flash_data *pdata = dev_get_platdata(&pdev->dev);
132	struct resource *memory = platform_get_resource(pdev, IORESOURCE_MEM, 0);
133	struct resource *flash_ambctl = platform_get_resource(pdev, IORESOURCE_MEM, 1);
134	struct async_state *state;
135
136	state = kzalloc(sizeof(*state), GFP_KERNEL);
137	if (!state)
138		return -ENOMEM;
139
140	state->map.name       = DRIVER_NAME;
141	state->map.read       = bfin_flash_read;
142	state->map.copy_from  = bfin_flash_copy_from;
143	state->map.write      = bfin_flash_write;
144	state->map.copy_to    = bfin_flash_copy_to;
145	state->map.bankwidth  = pdata->width;
146	state->map.size       = resource_size(memory);
147	state->map.virt       = (void __iomem *)memory->start;
148	state->map.phys       = memory->start;
149	state->map.map_priv_1 = (unsigned long)state;
150	state->enet_flash_pin = platform_get_irq(pdev, 0);
151	state->flash_ambctl0  = flash_ambctl->start;
152	state->flash_ambctl1  = flash_ambctl->end;
153
154	if (gpio_request(state->enet_flash_pin, DRIVER_NAME)) {
155		pr_devinit(KERN_ERR DRIVER_NAME ": Failed to request gpio %d\n", state->enet_flash_pin);
156		kfree(state);
157		return -EBUSY;
158	}
159	gpio_direction_output(state->enet_flash_pin, 1);
160
161	pr_devinit(KERN_NOTICE DRIVER_NAME ": probing %d-bit flash bus\n", state->map.bankwidth * 8);
162	state->mtd = do_map_probe(memory->name, &state->map);
163	if (!state->mtd) {
164		gpio_free(state->enet_flash_pin);
165		kfree(state);
166		return -ENXIO;
167	}
168
169	mtd_device_parse_register(state->mtd, part_probe_types, NULL,
170				  pdata->parts, pdata->nr_parts);
171
172	platform_set_drvdata(pdev, state);
173
174	return 0;
175}
176
177static int bfin_flash_remove(struct platform_device *pdev)
178{
179	struct async_state *state = platform_get_drvdata(pdev);
180	gpio_free(state->enet_flash_pin);
181	mtd_device_unregister(state->mtd);
182	map_destroy(state->mtd);
183	kfree(state);
184	return 0;
185}
186
187static struct platform_driver bfin_flash_driver = {
188	.probe		= bfin_flash_probe,
189	.remove		= bfin_flash_remove,
190	.driver		= {
191		.name	= DRIVER_NAME,
192	},
193};
194
195module_platform_driver(bfin_flash_driver);
196
197MODULE_LICENSE("GPL");
198MODULE_DESCRIPTION("MTD map driver for Blackfins with flash/ethernet on same async bank");
199