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/kernel.h>
 18#include <linux/module.h>
 19#include <linux/mtd/mtd.h>
 20#include <linux/mtd/map.h>
 21#include <linux/mtd/partitions.h>
 22#include <linux/mtd/physmap.h>
 23#include <linux/platform_device.h>
 24#include <linux/slab.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...) \
 33		({ 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 * const part_probe_types[] = {
125	"cmdlinepart", "RedBoot", NULL };
126
127static int bfin_flash_probe(struct platform_device *pdev)
128{
129	struct physmap_flash_data *pdata = dev_get_platdata(&pdev->dev);
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");