/*
   * at91_cf.c -- AT91 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/interrupt.h>
  #include <linux/slab.h>
  #include <linux/gpio.h>
  #include <linux/platform_data/atmel.h>
  #include <linux/io.h>
  #include <linux/sizes.h>
  #include <linux/of.h>
  #include <linux/of_device.h>
  #include <linux/of_gpio.h>
  
  #include <pcmcia/ss.h>
  
  #include <mach/at91rm9200_mc.h>
  #include <mach/at91_ramc.h>
  
  
  /*
   * A0..A10 work in each range; A23 indicates I/O space;  A25 is CFRNW;
   * some other bit in {A24,A22..A11} is nREG to flag memory access
   * (vs attributes).  So more than 2KB/region would just be waste.
   * Note: These are offsets from the physical base address.
   */
  #define	CF_ATTR_PHYS	(0)
  #define	CF_IO_PHYS	(1 << 23)
  #define	CF_MEM_PHYS	(0x017ff800)
  
  /*--------------------------------------------------------------------------*/
  
  struct at91_cf_socket {
  	struct pcmcia_socket	socket;
  
  	unsigned		present:1;
  
  	struct platform_device	*pdev;
  	struct at91_cf_data	*board;
  
  	unsigned long		phys_baseaddr;
  };
  
  static inline int at91_cf_present(struct at91_cf_socket *cf)
  {
  	return !gpio_get_value(cf->board->det_pin);
  }
  
  /*--------------------------------------------------------------------------*/
  
  static int at91_cf_ss_init(struct pcmcia_socket *s)
  {
  	return 0;
  }
  
  static irqreturn_t at91_cf_irq(int irq, void *_cf)
  {
  	struct at91_cf_socket *cf = _cf;
  
  	if (irq == gpio_to_irq(cf->board->det_pin)) {
  		unsigned present = at91_cf_present(cf);
  
  		/* kick pccard as needed */
  		if (present != cf->present) {
  			cf->present = present;
  			dev_dbg(&cf->pdev->dev, "card %s
  ",
  					present ? "present" : "gone");
  			pcmcia_parse_events(&cf->socket, SS_DETECT);
  		}
  	}
  
  	return IRQ_HANDLED;
  }
  
  static int at91_cf_get_status(struct pcmcia_socket *s, u_int *sp)
  {
  	struct at91_cf_socket	*cf;
  
  	if (!sp)
  		return -EINVAL;
  
  	cf = container_of(s, struct at91_cf_socket, socket);
  
  	/* NOTE: CF is always 3VCARD */
  	if (at91_cf_present(cf)) {
  		int rdy	= gpio_is_valid(cf->board->irq_pin);	/* RDY/nIRQ */
  		int vcc	= gpio_is_valid(cf->board->vcc_pin);
  
  		*sp = SS_DETECT | SS_3VCARD;
  		if (!rdy || gpio_get_value(cf->board->irq_pin))
  			*sp |= SS_READY;
  		if (!vcc || gpio_get_value(cf->board->vcc_pin))
  			*sp |= SS_POWERON;
  	} else
  		*sp = 0;
  
  	return 0;
  }
  
  static int
  at91_cf_set_socket(struct pcmcia_socket *sock, struct socket_state_t *s)
  {
  	struct at91_cf_socket	*cf;
  
  	cf = container_of(sock, struct at91_cf_socket, socket);
  
  	/* switch Vcc if needed and possible */
  	if (gpio_is_valid(cf->board->vcc_pin)) {
  		switch (s->Vcc) {
  		case 0:
  			gpio_set_value(cf->board->vcc_pin, 0);
  			break;
  		case 33:
  			gpio_set_value(cf->board->vcc_pin, 1);
  			break;
  		default:
  			return -EINVAL;
  		}
  	}
  
  	/* toggle reset if needed */
  	gpio_set_value(cf->board->rst_pin, s->flags & SS_RESET);
  
  	dev_dbg(&cf->pdev->dev, "Vcc %d, io_irq %d, flags %04x csc %04x
  ",
  				s->Vcc, s->io_irq, s->flags, s->csc_mask);
  
  	return 0;
  }
  
  static int at91_cf_ss_suspend(struct pcmcia_socket *s)
  {
  	return at91_cf_set_socket(s, &dead_socket);
  }
  
  /* we already mapped the I/O region */
  static int at91_cf_set_io_map(struct pcmcia_socket *s, struct pccard_io_map *io)
  {
  	struct at91_cf_socket	*cf;
  	u32			csr;
  
  	cf = container_of(s, struct at91_cf_socket, socket);
  	io->flags &= (MAP_ACTIVE | MAP_16BIT | MAP_AUTOSZ);
  
  	/*
  	 * Use 16 bit accesses unless/until we need 8-bit i/o space.
  	 */
  	csr = at91_ramc_read(0, AT91_SMC_CSR(cf->board->chipselect)) & ~AT91_SMC_DBW;
  
  	/*
  	 * NOTE: this CF controller ignores IOIS16, so we can't really do
  	 * MAP_AUTOSZ.  The 16bit mode allows single byte access on either
  	 * D0-D7 (even addr) or D8-D15 (odd), so it's close enough for many
  	 * purposes (and handles ide-cs).
  	 *
  	 * The 8bit mode is needed for odd byte access on D0-D7.  It seems
  	 * some cards only like that way to get at the odd byte, despite
  	 * CF 3.0 spec table 35 also giving the D8-D15 option.
  	 */
  	if (!(io->flags & (MAP_16BIT | MAP_AUTOSZ))) {
  		csr |= AT91_SMC_DBW_8;
  		dev_dbg(&cf->pdev->dev, "8bit i/o bus
  ");
  	} else {
  		csr |= AT91_SMC_DBW_16;
  		dev_dbg(&cf->pdev->dev, "16bit i/o bus
  ");
  	}
  	at91_ramc_write(0, AT91_SMC_CSR(cf->board->chipselect), csr);
  
  	io->start = cf->socket.io_offset;
  	io->stop = io->start + SZ_2K - 1;
  
  	return 0;
  }
  
  /* pcmcia layer maps/unmaps mem regions */
  static int
  at91_cf_set_mem_map(struct pcmcia_socket *s, struct pccard_mem_map *map)
  {
  	struct at91_cf_socket	*cf;
  
  	if (map->card_start)
  		return -EINVAL;
  
  	cf = container_of(s, struct at91_cf_socket, socket);
  
  	map->flags &= (MAP_ACTIVE | MAP_ATTRIB | MAP_16BIT);
  	if (map->flags & MAP_ATTRIB)
  		map->static_start = cf->phys_baseaddr + CF_ATTR_PHYS;
  	else
  		map->static_start = cf->phys_baseaddr + CF_MEM_PHYS;
  
  	return 0;
  }
  
  static struct pccard_operations at91_cf_ops = {
  	.init			= at91_cf_ss_init,
  	.suspend		= at91_cf_ss_suspend,
  	.get_status		= at91_cf_get_status,
  	.set_socket		= at91_cf_set_socket,
  	.set_io_map		= at91_cf_set_io_map,
  	.set_mem_map		= at91_cf_set_mem_map,
  };
  
  /*--------------------------------------------------------------------------*/
  
  #if defined(CONFIG_OF)
  static const struct of_device_id at91_cf_dt_ids[] = {
  	{ .compatible = "atmel,at91rm9200-cf" },
  	{ /* sentinel */ }
  };
  MODULE_DEVICE_TABLE(of, at91_cf_dt_ids);
  
  static int at91_cf_dt_init(struct platform_device *pdev)
  {
  	struct at91_cf_data *board;
  
  	board = devm_kzalloc(&pdev->dev, sizeof(*board), GFP_KERNEL);
  	if (!board)
  		return -ENOMEM;
  
  	board->irq_pin = of_get_gpio(pdev->dev.of_node, 0);
  	board->det_pin = of_get_gpio(pdev->dev.of_node, 1);
  	board->vcc_pin = of_get_gpio(pdev->dev.of_node, 2);
  	board->rst_pin = of_get_gpio(pdev->dev.of_node, 3);
  
  	pdev->dev.platform_data = board;
  
  	return 0;
  }
  #else
  static int at91_cf_dt_init(struct platform_device *pdev)
  {
  	return -ENODEV;
  }
  #endif
  
  static int at91_cf_probe(struct platform_device *pdev)
  {
  	struct at91_cf_socket	*cf;
  	struct at91_cf_data	*board = pdev->dev.platform_data;
  	struct resource		*io;
  	int			status;
  
  	if (!board) {
  		status = at91_cf_dt_init(pdev);
  		if (status)
  			return status;
  
  		board = pdev->dev.platform_data;
  	}
  
  	if (!gpio_is_valid(board->det_pin) || !gpio_is_valid(board->rst_pin))
  		return -ENODEV;
  
  	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!io)
  		return -ENODEV;
  
  	cf = devm_kzalloc(&pdev->dev, sizeof(*cf), GFP_KERNEL);
  	if (!cf)
  		return -ENOMEM;
  
  	cf->board = board;
  	cf->pdev = pdev;
  	cf->phys_baseaddr = io->start;
  	platform_set_drvdata(pdev, cf);
  
  	/* must be a GPIO; ergo must trigger on both edges */
  	status = devm_gpio_request(&pdev->dev, board->det_pin, "cf_det");
  	if (status < 0)
  		return status;
  
  	status = devm_request_irq(&pdev->dev, gpio_to_irq(board->det_pin),
  					at91_cf_irq, 0, "at91_cf detect", cf);
  	if (status < 0)
  		return status;
  
  	device_init_wakeup(&pdev->dev, 1);
  
  	status = devm_gpio_request(&pdev->dev, board->rst_pin, "cf_rst");
  	if (status < 0)
  		goto fail0a;
  
  	if (gpio_is_valid(board->vcc_pin)) {
  		status = devm_gpio_request(&pdev->dev, board->vcc_pin, "cf_vcc");
  		if (status < 0)
  			goto fail0a;
  	}
  
  	/*
  	 * The card driver will request this irq later as needed.
  	 * but it causes lots of "irqNN: nobody cared" messages
  	 * unless we report that we handle everything (sigh).
  	 * (Note:  DK board doesn't wire the IRQ pin...)
  	 */
  	if (gpio_is_valid(board->irq_pin)) {
  		status = devm_gpio_request(&pdev->dev, board->irq_pin, "cf_irq");
  		if (status < 0)
  			goto fail0a;
  
  		status = devm_request_irq(&pdev->dev, gpio_to_irq(board->irq_pin),
  					at91_cf_irq, IRQF_SHARED, "at91_cf", cf);
  		if (status < 0)
  			goto fail0a;
  		cf->socket.pci_irq = gpio_to_irq(board->irq_pin);
  	} else
  		cf->socket.pci_irq = nr_irqs + 1;
  
  	/* pcmcia layer only remaps "real" memory not iospace */
  	cf->socket.io_offset = (unsigned long) devm_ioremap(&pdev->dev,
  					cf->phys_baseaddr + CF_IO_PHYS, SZ_2K);
  	if (!cf->socket.io_offset) {
  		status = -ENXIO;
  		goto fail0a;
  	}
  
  	/* reserve chip-select regions */
  	if (!devm_request_mem_region(&pdev->dev, io->start, resource_size(io), "at91_cf")) {
  		status = -ENXIO;
  		goto fail0a;
  	}
  
  	dev_info(&pdev->dev, "irqs det #%d, io #%d
  ",
  		gpio_to_irq(board->det_pin), gpio_to_irq(board->irq_pin));
  
  	cf->socket.owner = THIS_MODULE;
  	cf->socket.dev.parent = &pdev->dev;
  	cf->socket.ops = &at91_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 = io;
  
  	status = pcmcia_register_socket(&cf->socket);
  	if (status < 0)
  		goto fail0a;
  
  	return 0;
  
  fail0a:
  	device_init_wakeup(&pdev->dev, 0);
  	return status;
  }
  
  static int at91_cf_remove(struct platform_device *pdev)
  {
  	struct at91_cf_socket	*cf = platform_get_drvdata(pdev);
  
  	pcmcia_unregister_socket(&cf->socket);
  	device_init_wakeup(&pdev->dev, 0);
  
  	return 0;
  }
  
  #ifdef	CONFIG_PM
  
  static int at91_cf_suspend(struct platform_device *pdev, pm_message_t mesg)
  {
  	struct at91_cf_socket	*cf = platform_get_drvdata(pdev);
  	struct at91_cf_data	*board = cf->board;
  
  	if (device_may_wakeup(&pdev->dev)) {
  		enable_irq_wake(gpio_to_irq(board->det_pin));
  		if (gpio_is_valid(board->irq_pin))
  			enable_irq_wake(gpio_to_irq(board->irq_pin));
  	}
  	return 0;
  }
  
  static int at91_cf_resume(struct platform_device *pdev)
  {
  	struct at91_cf_socket	*cf = platform_get_drvdata(pdev);
  	struct at91_cf_data	*board = cf->board;
  
  	if (device_may_wakeup(&pdev->dev)) {
  		disable_irq_wake(gpio_to_irq(board->det_pin));
  		if (gpio_is_valid(board->irq_pin))
  			disable_irq_wake(gpio_to_irq(board->irq_pin));
  	}
  
  	return 0;
  }
  
  #else
  #define	at91_cf_suspend		NULL
  #define	at91_cf_resume		NULL
  #endif
  
  static struct platform_driver at91_cf_driver = {
  	.driver = {
  		.name		= "at91_cf",
  		.owner		= THIS_MODULE,
  		.of_match_table = of_match_ptr(at91_cf_dt_ids),
  	},
  	.probe		= at91_cf_probe,
  	.remove		= at91_cf_remove,
  	.suspend	= at91_cf_suspend,
  	.resume		= at91_cf_resume,
  };
  
  module_platform_driver(at91_cf_driver);
  
  MODULE_DESCRIPTION("AT91 Compact Flash Driver");
  MODULE_AUTHOR("David Brownell");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:at91_cf");