/*
   * omap_cf.c -- OMAP 16xx CompactFlash controller driver
   *
   * Copyright (c) 2005 David Brownell
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>

  #include <linux/platform_device.h>

  #include <linux/errno.h>
  #include <linux/init.h>
  #include <linux/delay.h>
  #include <linux/interrupt.h>

  #include <linux/slab.h>

  
  #include <pcmcia/ss.h>

  #include <mach/hardware.h>

  #include <asm/io.h>

  #include <asm/sizes.h>

  #include <plat/mux.h>
  #include <plat/tc.h>

  
  
  /* NOTE:  don't expect this to support many I/O cards.  The 16xx chips have
   * hard-wired timings to support Compact Flash memory cards; they won't work
   * with various other devices (like WLAN adapters) without some external
   * logic to help out.
   *
   * NOTE:  CF controller docs disagree with address space docs as to where
   * CF_BASE really lives; this is a doc erratum.
   */
  #define	CF_BASE	0xfffe2800
  
  /* status; read after IRQ */

  #define CF_STATUS			(CF_BASE + 0x00)

  #	define	CF_STATUS_BAD_READ	(1 << 2)
  #	define	CF_STATUS_BAD_WRITE	(1 << 1)
  #	define	CF_STATUS_CARD_DETECT	(1 << 0)
  
  /* which chipselect (CS0..CS3) is used for CF (active low) */

  #define CF_CFG				(CF_BASE + 0x02)

  
  /* card reset */

  #define CF_CONTROL			(CF_BASE + 0x04)

  #	define	CF_CONTROL_RESET	(1 << 0)

  #define omap_cf_present() (!(omap_readw(CF_STATUS) & CF_STATUS_CARD_DETECT))

  
  /*--------------------------------------------------------------------------*/
  
  static const char driver_name[] = "omap_cf";
  
  struct omap_cf_socket {
  	struct pcmcia_socket	socket;
  
  	struct timer_list	timer;
  	unsigned		present:1;
  	unsigned		active:1;
  
  	struct platform_device	*pdev;
  	unsigned long		phys_cf;
  	u_int			irq;

  	struct resource		iomem;

  };
  
  #define	POLL_INTERVAL		(2 * HZ)

  /*--------------------------------------------------------------------------*/
  
  static int omap_cf_ss_init(struct pcmcia_socket *s)
  {
  	return 0;
  }
  
  /* the timer is primarily to kick this socket's pccardd */
  static void omap_cf_timer(unsigned long _cf)
  {
  	struct omap_cf_socket	*cf = (void *) _cf;
  	unsigned		present = omap_cf_present();
  
  	if (present != cf->present) {
  		cf->present = present;
  		pr_debug("%s: card %s
  ", driver_name,
  			present ? "present" : "gone");
  		pcmcia_parse_events(&cf->socket, SS_DETECT);
  	}
  
  	if (cf->active)
  		mod_timer(&cf->timer, jiffies + POLL_INTERVAL);
  }
  
  /* This irq handler prevents "irqNNN: nobody cared" messages as drivers
   * claim the card's IRQ.  It may also detect some card insertions, but
   * not removals; it can't always eliminate timer irqs.
   */

  static irqreturn_t omap_cf_irq(int irq, void *_cf)

  {
  	omap_cf_timer((unsigned long)_cf);
  	return IRQ_HANDLED;
  }
  
  static int omap_cf_get_status(struct pcmcia_socket *s, u_int *sp)
  {
  	if (!sp)
  		return -EINVAL;

  	/* NOTE CF is always 3VCARD */

  	if (omap_cf_present()) {
  		struct omap_cf_socket	*cf;
  
  		*sp = SS_READY | SS_DETECT | SS_POWERON | SS_3VCARD;
  		cf = container_of(s, struct omap_cf_socket, socket);

  		s->pcmcia_irq = 0;

  		s->pci_irq = cf->irq;

  	} else
  		*sp = 0;
  	return 0;
  }
  
  static int
  omap_cf_set_socket(struct pcmcia_socket *sock, struct socket_state_t *s)
  {
  	u16		control;

  	/* REVISIT some non-OSK boards may support power switching */

  	switch (s->Vcc) {
  	case 0:
  	case 33:
  		break;
  	default:
  		return -EINVAL;
  	}

  	control = omap_readw(CF_CONTROL);

  	if (s->flags & SS_RESET)

  		omap_writew(CF_CONTROL_RESET, CF_CONTROL);

  	else

  		omap_writew(0, CF_CONTROL);

  
  	pr_debug("%s: Vcc %d, io_irq %d, flags %04x csc %04x
  ",
  		driver_name, s->Vcc, s->io_irq, s->flags, s->csc_mask);
  
  	return 0;
  }
  
  static int omap_cf_ss_suspend(struct pcmcia_socket *s)
  {

  	pr_debug("%s: %s
  ", driver_name, __func__);

  	return omap_cf_set_socket(s, &dead_socket);
  }
  
  /* regions are 2K each:  mem, attrib, io (and reserved-for-ide) */
  
  static int
  omap_cf_set_io_map(struct pcmcia_socket *s, struct pccard_io_map *io)
  {
  	struct omap_cf_socket	*cf;
  
  	cf = container_of(s, struct omap_cf_socket, socket);
  	io->flags &= MAP_ACTIVE|MAP_ATTRIB|MAP_16BIT;
  	io->start = cf->phys_cf + SZ_4K;
  	io->stop = io->start + SZ_2K - 1;
  	return 0;
  }
  
  static int
  omap_cf_set_mem_map(struct pcmcia_socket *s, struct pccard_mem_map *map)
  {
  	struct omap_cf_socket	*cf;
  
  	if (map->card_start)
  		return -EINVAL;
  	cf = container_of(s, struct omap_cf_socket, socket);
  	map->static_start = cf->phys_cf;
  	map->flags &= MAP_ACTIVE|MAP_ATTRIB|MAP_16BIT;
  	if (map->flags & MAP_ATTRIB)
  		map->static_start += SZ_2K;
  	return 0;
  }
  
  static struct pccard_operations omap_cf_ops = {
  	.init			= omap_cf_ss_init,
  	.suspend		= omap_cf_ss_suspend,
  	.get_status		= omap_cf_get_status,
  	.set_socket		= omap_cf_set_socket,
  	.set_io_map		= omap_cf_set_io_map,
  	.set_mem_map		= omap_cf_set_mem_map,
  };
  
  /*--------------------------------------------------------------------------*/
  
  /*
   * NOTE:  right now the only board-specific platform_data is
   * "what chipselect is used".  Boards could want more.
   */

  static int __init omap_cf_probe(struct platform_device *pdev)

  {
  	unsigned		seg;
  	struct omap_cf_socket	*cf;

  	int			irq;
  	int			status;

  	seg = (int) pdev->dev.platform_data;

  	if (seg == 0 || seg > 3)
  		return -ENODEV;
  
  	/* either CFLASH.IREQ (INT_1610_CF) or some GPIO */
  	irq = platform_get_irq(pdev, 0);

  	if (irq < 0)

  		return -EINVAL;

  	cf = kzalloc(sizeof *cf, GFP_KERNEL);

  	if (!cf)
  		return -ENOMEM;
  	init_timer(&cf->timer);
  	cf->timer.function = omap_cf_timer;
  	cf->timer.data = (unsigned long) cf;
  
  	cf->pdev = pdev;

  	platform_set_drvdata(pdev, cf);

  
  	/* this primarily just shuts up irq handling noise */

  	status = request_irq(irq, omap_cf_irq, IRQF_SHARED,

  			driver_name, cf);
  	if (status < 0)
  		goto fail0;
  	cf->irq = irq;
  	cf->socket.pci_irq = irq;
  
  	switch (seg) {
  	/* NOTE: CS0 could be configured too ... */
  	case 1:
  		cf->phys_cf = OMAP_CS1_PHYS;
  		break;
  	case 2:
  		cf->phys_cf = OMAP_CS2_PHYS;
  		break;
  	case 3:
  		cf->phys_cf = omap_cs3_phys();
  		break;
  	default:
  		goto  fail1;
  	}

  	cf->iomem.start = cf->phys_cf;
  	cf->iomem.end = cf->iomem.end + SZ_8K - 1;
  	cf->iomem.flags = IORESOURCE_MEM;

  
  	/* pcmcia layer only remaps "real" memory */
  	cf->socket.io_offset = (unsigned long)
  			ioremap(cf->phys_cf + SZ_4K, SZ_2K);
  	if (!cf->socket.io_offset)
  		goto fail1;
  
  	if (!request_mem_region(cf->phys_cf, SZ_8K, driver_name))
  		goto fail1;
  
  	/* NOTE:  CF conflicts with MMC1 */
  	omap_cfg_reg(W11_1610_CF_CD1);
  	omap_cfg_reg(P11_1610_CF_CD2);
  	omap_cfg_reg(R11_1610_CF_IOIS16);
  	omap_cfg_reg(V10_1610_CF_IREQ);
  	omap_cfg_reg(W10_1610_CF_RESET);

  	omap_writew(~(1 << seg), CF_CFG);

  
  	pr_info("%s: cs%d on irq %d
  ", driver_name, seg, irq);
  
  	/* NOTE:  better EMIFS setup might support more cards; but the
  	 * TRM only shows how to affect regular flash signals, not their
  	 * CF/PCMCIA variants...
  	 */
  	pr_debug("%s: cs%d, previous ccs %08x acs %08x
  ", driver_name,

  		seg, omap_readl(EMIFS_CCS(seg)), omap_readl(EMIFS_ACS(seg)));
  	omap_writel(0x0004a1b3, EMIFS_CCS(seg));	/* synch mode 4 etc */
  	omap_writel(0x00000000, EMIFS_ACS(seg));	/* OE hold/setup */

  
  	/* CF uses armxor_ck, which is "always" available */
  
  	pr_debug("%s: sts %04x cfg %04x control %04x %s
  ", driver_name,

  		omap_readw(CF_STATUS), omap_readw(CF_CFG),
  		omap_readw(CF_CONTROL),

  		omap_cf_present() ? "present" : "(not present)");
  
  	cf->socket.owner = THIS_MODULE;

  	cf->socket.dev.parent = &pdev->dev;

  	cf->socket.ops = &omap_cf_ops;
  	cf->socket.resource_ops = &pccard_static_ops;
  	cf->socket.features = SS_CAP_PCCARD | SS_CAP_STATIC_MAP
  				| SS_CAP_MEM_ALIGN;
  	cf->socket.map_size = SZ_2K;

  	cf->socket.io[0].res = &cf->iomem;

  
  	status = pcmcia_register_socket(&cf->socket);
  	if (status < 0)
  		goto fail2;
  
  	cf->active = 1;
  	mod_timer(&cf->timer, jiffies + POLL_INTERVAL);
  	return 0;
  
  fail2:

  	release_mem_region(cf->phys_cf, SZ_8K);
  fail1:

  	if (cf->socket.io_offset)
  		iounmap((void __iomem *) cf->socket.io_offset);

  	free_irq(irq, cf);
  fail0:
  	kfree(cf);
  	return status;
  }

  static int __exit omap_cf_remove(struct platform_device *pdev)

  {

  	struct omap_cf_socket *cf = platform_get_drvdata(pdev);

  
  	cf->active = 0;
  	pcmcia_unregister_socket(&cf->socket);
  	del_timer_sync(&cf->timer);
  	iounmap((void __iomem *) cf->socket.io_offset);
  	release_mem_region(cf->phys_cf, SZ_8K);
  	free_irq(cf->irq, cf);
  	kfree(cf);
  	return 0;
  }

  static struct platform_driver omap_cf_driver = {
  	.driver = {
  		.name	= (char *) driver_name,

  		.owner	= THIS_MODULE,

  	},
  	.remove		= __exit_p(omap_cf_remove),

  };
  
  static int __init omap_cf_init(void)
  {
  	if (cpu_is_omap16xx())

  		return platform_driver_probe(&omap_cf_driver, omap_cf_probe);

  	return -ENODEV;

  }
  
  static void __exit omap_cf_exit(void)
  {
  	if (cpu_is_omap16xx())

  		platform_driver_unregister(&omap_cf_driver);

  }
  
  module_init(omap_cf_init);
  module_exit(omap_cf_exit);
  
  MODULE_DESCRIPTION("OMAP CF Driver");
  MODULE_LICENSE("GPL");

  MODULE_ALIAS("platform:omap_cf");