/*
   * drivers/mtd/maps/bfin-async-flash.c
   *
   * Handle the case where flash memory and ethernet mac/phy are
   * mapped onto the same async bank.  The BF533-STAMP does this
   * for example.  All board-specific configuration goes in your
   * board resources file.
   *
   * Copyright 2000 Nicolas Pitre <nico@fluxnic.net>
   * Copyright 2005-2008 Analog Devices Inc.
   *
   * Enter bugs at http://blackfin.uclinux.org/
   *
   * Licensed under the GPL-2 or later.
   */
  
  #include <linux/init.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/mtd/mtd.h>
  #include <linux/mtd/map.h>
  #include <linux/mtd/partitions.h>
  #include <linux/mtd/physmap.h>
  #include <linux/platform_device.h>
  #include <linux/slab.h>
  #include <linux/types.h>
  
  #include <asm/blackfin.h>
  #include <linux/gpio.h>
  #include <linux/io.h>
  #include <asm/unaligned.h>
  
  #define pr_devinit(fmt, args...) \
  		({ static const char __fmt[] = fmt; printk(__fmt, ## args); })
  
  #define DRIVER_NAME "bfin-async-flash"
  
  struct async_state {
  	struct mtd_info *mtd;
  	struct map_info map;
  	int enet_flash_pin;
  	uint32_t flash_ambctl0, flash_ambctl1;
  	uint32_t save_ambctl0, save_ambctl1;
  	unsigned long irq_flags;
  };
  
  static void switch_to_flash(struct async_state *state)
  {
  	local_irq_save(state->irq_flags);
  
  	gpio_set_value(state->enet_flash_pin, 0);
  
  	state->save_ambctl0 = bfin_read_EBIU_AMBCTL0();
  	state->save_ambctl1 = bfin_read_EBIU_AMBCTL1();
  	bfin_write_EBIU_AMBCTL0(state->flash_ambctl0);
  	bfin_write_EBIU_AMBCTL1(state->flash_ambctl1);
  	SSYNC();
  }
  
  static void switch_back(struct async_state *state)
  {
  	bfin_write_EBIU_AMBCTL0(state->save_ambctl0);
  	bfin_write_EBIU_AMBCTL1(state->save_ambctl1);
  	SSYNC();
  
  	gpio_set_value(state->enet_flash_pin, 1);
  
  	local_irq_restore(state->irq_flags);
  }
  
  static map_word bfin_flash_read(struct map_info *map, unsigned long ofs)
  {
  	struct async_state *state = (struct async_state *)map->map_priv_1;
  	uint16_t word;
  	map_word test;
  
  	switch_to_flash(state);
  
  	word = readw(map->virt + ofs);
  
  	switch_back(state);
  
  	test.x[0] = word;
  	return test;
  }
  
  static void bfin_flash_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
  {
  	struct async_state *state = (struct async_state *)map->map_priv_1;
  
  	switch_to_flash(state);
  
  	memcpy(to, map->virt + from, len);
  
  	switch_back(state);
  }
  
  static void bfin_flash_write(struct map_info *map, map_word d1, unsigned long ofs)
  {
  	struct async_state *state = (struct async_state *)map->map_priv_1;
  	uint16_t d;
  
  	d = d1.x[0];
  
  	switch_to_flash(state);
  
  	writew(d, map->virt + ofs);
  	SSYNC();
  
  	switch_back(state);
  }
  
  static void bfin_flash_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
  {
  	struct async_state *state = (struct async_state *)map->map_priv_1;
  
  	switch_to_flash(state);
  
  	memcpy(map->virt + to, from, len);
  	SSYNC();
  
  	switch_back(state);
  }
  
  static const char * const part_probe_types[] = {
  	"cmdlinepart", "RedBoot", NULL };
  
  static int bfin_flash_probe(struct platform_device *pdev)
  {
  	int ret;
  	struct physmap_flash_data *pdata = dev_get_platdata(&pdev->dev);
  	struct resource *memory = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	struct resource *flash_ambctl = platform_get_resource(pdev, IORESOURCE_MEM, 1);
  	struct async_state *state;
  
  	state = kzalloc(sizeof(*state), GFP_KERNEL);
  	if (!state)
  		return -ENOMEM;
  
  	state->map.name       = DRIVER_NAME;
  	state->map.read       = bfin_flash_read;
  	state->map.copy_from  = bfin_flash_copy_from;
  	state->map.write      = bfin_flash_write;
  	state->map.copy_to    = bfin_flash_copy_to;
  	state->map.bankwidth  = pdata->width;
  	state->map.size       = resource_size(memory);
  	state->map.virt       = (void __iomem *)memory->start;
  	state->map.phys       = memory->start;
  	state->map.map_priv_1 = (unsigned long)state;
  	state->enet_flash_pin = platform_get_irq(pdev, 0);
  	state->flash_ambctl0  = flash_ambctl->start;
  	state->flash_ambctl1  = flash_ambctl->end;
  
  	if (gpio_request(state->enet_flash_pin, DRIVER_NAME)) {
  		pr_devinit(KERN_ERR DRIVER_NAME ": Failed to request gpio %d
  ", state->enet_flash_pin);
  		kfree(state);
  		return -EBUSY;
  	}
  	gpio_direction_output(state->enet_flash_pin, 1);
  
  	pr_devinit(KERN_NOTICE DRIVER_NAME ": probing %d-bit flash bus
  ", state->map.bankwidth * 8);
  	state->mtd = do_map_probe(memory->name, &state->map);
  	if (!state->mtd) {
  		gpio_free(state->enet_flash_pin);
  		kfree(state);
  		return -ENXIO;
  	}
  
  	mtd_device_parse_register(state->mtd, part_probe_types, NULL,
  				  pdata->parts, pdata->nr_parts);
  
  	platform_set_drvdata(pdev, state);
  
  	return 0;
  }
  
  static int bfin_flash_remove(struct platform_device *pdev)
  {
  	struct async_state *state = platform_get_drvdata(pdev);
  	gpio_free(state->enet_flash_pin);
  	mtd_device_unregister(state->mtd);
  	map_destroy(state->mtd);
  	kfree(state);
  	return 0;
  }
  
  static struct platform_driver bfin_flash_driver = {
  	.probe		= bfin_flash_probe,
  	.remove		= bfin_flash_remove,
  	.driver		= {
  		.name	= DRIVER_NAME,
  	},
  };
  
  module_platform_driver(bfin_flash_driver);
  
  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("MTD map driver for Blackfins with flash/ethernet on same async bank");