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	struct mtd_partition *parts;
 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 *part_probe_types[] = { "cmdlinepart", "RedBoot", NULL };
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_flash_read;
141	state->map.copy_from  = bfin_flash_copy_from;
142	state->map.write      = bfin_flash_write;
143	state->map.copy_to    = bfin_flash_copy_to;
144	state->map.bankwidth  = pdata->width;
145	state->map.size       = resource_size(memory);
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	ret = parse_mtd_partitions(state->mtd, part_probe_types, &pdata->parts, 0);
169	if (ret > 0) {
170		pr_devinit(KERN_NOTICE DRIVER_NAME ": Using commandline partition definition\n");
171		mtd_device_register(state->mtd, pdata->parts, ret);
172		state->parts = pdata->parts;
173	} else if (pdata->nr_parts) {
174		pr_devinit(KERN_NOTICE DRIVER_NAME ": Using board partition definition\n");
175		mtd_device_register(state->mtd, pdata->parts, pdata->nr_parts);
176	} else {
177		pr_devinit(KERN_NOTICE DRIVER_NAME ": no partition info available, registering whole flash at once\n");
178		mtd_device_register(state->mtd, NULL, 0);
179	}
180
181	platform_set_drvdata(pdev, state);
182
183	return 0;
184}
185
186static int __devexit bfin_flash_remove(struct platform_device *pdev)
187{
188	struct async_state *state = platform_get_drvdata(pdev);
189	gpio_free(state->enet_flash_pin);
190	mtd_device_unregister(state->mtd);
191	kfree(state->parts);
192	map_destroy(state->mtd);
193	kfree(state);
194	return 0;
195}
196
197static struct platform_driver bfin_flash_driver = {
198	.probe		= bfin_flash_probe,
199	.remove		= __devexit_p(bfin_flash_remove),
200	.driver		= {
201		.name	= DRIVER_NAME,
202	},
203};
204
205static int __init bfin_flash_init(void)
206{
207	return platform_driver_register(&bfin_flash_driver);
208}
209module_init(bfin_flash_init);
210
211static void __exit bfin_flash_exit(void)
212{
213	platform_driver_unregister(&bfin_flash_driver);
214}
215module_exit(bfin_flash_exit);
216
217MODULE_LICENSE("GPL");
218MODULE_DESCRIPTION("MTD map driver for Blackfins with flash/ethernet on same async bank");