/*
   * Cyclades PC300 synchronous serial card driver for Linux
   *
   * Copyright (C) 2000-2008 Krzysztof Halasa <khc@pm.waw.pl>
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of version 2 of the GNU General Public License
   * as published by the Free Software Foundation.
   *
   * For information see <http://www.kernel.org/pub/linux/utils/net/hdlc/>.
   *
   * Sources of information:
   *    Hitachi HD64572 SCA-II User's Manual
   *    Original Cyclades PC300 Linux driver
   *
   * This driver currently supports only PC300/RSV (V.24/V.35) and
   * PC300/X21 cards.
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/slab.h>
  #include <linux/sched.h>
  #include <linux/types.h>
  #include <linux/fcntl.h>
  #include <linux/in.h>
  #include <linux/string.h>
  #include <linux/errno.h>
  #include <linux/init.h>
  #include <linux/ioport.h>
  #include <linux/moduleparam.h>
  #include <linux/netdevice.h>
  #include <linux/hdlc.h>
  #include <linux/pci.h>
  #include <linux/delay.h>
  #include <asm/io.h>
  
  #include "hd64572.h"
  
  #undef DEBUG_PKT
  #define DEBUG_RINGS
  
  #define PC300_PLX_SIZE		0x80    /* PLX control window size (128 B) */
  #define PC300_SCA_SIZE		0x400   /* SCA window size (1 KB) */
  #define MAX_TX_BUFFERS		10
  
  static int pci_clock_freq = 33000000;
  static int use_crystal_clock = 0;
  static unsigned int CLOCK_BASE;
  
  /* Masks to access the init_ctrl PLX register */
  #define PC300_CLKSEL_MASK	 (0x00000004UL)
  #define PC300_CHMEDIA_MASK(port) (0x00000020UL << ((port) * 3))
  #define PC300_CTYPE_MASK	 (0x00000800UL)
  
  
  enum { PC300_RSV = 1, PC300_X21, PC300_TE }; /* card types */
  
  /*
   *      PLX PCI9050-1 local configuration and shared runtime registers.
   *      This structure can be used to access 9050 registers (memory mapped).
   */
  typedef struct {
  	u32 loc_addr_range[4];	/* 00-0Ch : Local Address Ranges */
  	u32 loc_rom_range;	/* 10h : Local ROM Range */
  	u32 loc_addr_base[4];	/* 14-20h : Local Address Base Addrs */
  	u32 loc_rom_base;	/* 24h : Local ROM Base */
  	u32 loc_bus_descr[4];	/* 28-34h : Local Bus Descriptors */
  	u32 rom_bus_descr;	/* 38h : ROM Bus Descriptor */
  	u32 cs_base[4];		/* 3C-48h : Chip Select Base Addrs */
  	u32 intr_ctrl_stat;	/* 4Ch : Interrupt Control/Status */
  	u32 init_ctrl;		/* 50h : EEPROM ctrl, Init Ctrl, etc */
  }plx9050;
  
  
  
  typedef struct port_s {
  	struct napi_struct napi;
  	struct net_device *netdev;
  	struct card_s *card;
  	spinlock_t lock;	/* TX lock */
  	sync_serial_settings settings;
  	int rxpart;		/* partial frame received, next frame invalid*/
  	unsigned short encoding;
  	unsigned short parity;
  	unsigned int iface;
  	u16 rxin;		/* rx ring buffer 'in' pointer */
  	u16 txin;		/* tx ring buffer 'in' and 'last' pointers */
  	u16 txlast;
  	u8 rxs, txs, tmc;	/* SCA registers */
  	u8 chan;		/* physical port # - 0 or 1 */
  }port_t;
  
  
  
  typedef struct card_s {
  	int type;		/* RSV, X21, etc. */
  	int n_ports;		/* 1 or 2 ports */
  	u8 __iomem *rambase;	/* buffer memory base (virtual) */
  	u8 __iomem *scabase;	/* SCA memory base (virtual) */
  	plx9050 __iomem *plxbase; /* PLX registers memory base (virtual) */
  	u32 init_ctrl_value;	/* Saved value - 9050 bug workaround */
  	u16 rx_ring_buffers;	/* number of buffers in a ring */
  	u16 tx_ring_buffers;
  	u16 buff_offset;	/* offset of first buffer of first channel */
  	u8 irq;			/* interrupt request level */
  
  	port_t ports[2];
  }card_t;
  
  
  #define get_port(card, port)	     ((port) < (card)->n_ports ? \
  					 (&(card)->ports[port]) : (NULL))
  
  #include "hd64572.c"
  
  
  static void pc300_set_iface(port_t *port)
  {
  	card_t *card = port->card;
  	u32 __iomem * init_ctrl = &card->plxbase->init_ctrl;
  	u16 msci = get_msci(port);
  	u8 rxs = port->rxs & CLK_BRG_MASK;
  	u8 txs = port->txs & CLK_BRG_MASK;
  
  	sca_out(EXS_TES1, (port->chan ? MSCI1_OFFSET : MSCI0_OFFSET) + EXS,
  		port->card);
  	switch(port->settings.clock_type) {
  	case CLOCK_INT:
  		rxs |= CLK_BRG; /* BRG output */
  		txs |= CLK_PIN_OUT | CLK_TX_RXCLK; /* RX clock */
  		break;
  
  	case CLOCK_TXINT:
  		rxs |= CLK_LINE; /* RXC input */
  		txs |= CLK_PIN_OUT | CLK_BRG; /* BRG output */
  		break;
  
  	case CLOCK_TXFROMRX:
  		rxs |= CLK_LINE; /* RXC input */
  		txs |= CLK_PIN_OUT | CLK_TX_RXCLK; /* RX clock */
  		break;
  
  	default:		/* EXTernal clock */
  		rxs |= CLK_LINE; /* RXC input */
  		txs |= CLK_PIN_OUT | CLK_LINE; /* TXC input */
  		break;
  	}
  
  	port->rxs = rxs;
  	port->txs = txs;
  	sca_out(rxs, msci + RXS, card);
  	sca_out(txs, msci + TXS, card);
  	sca_set_port(port);
  
  	if (port->card->type == PC300_RSV) {
  		if (port->iface == IF_IFACE_V35)
  			writel(card->init_ctrl_value |
  			       PC300_CHMEDIA_MASK(port->chan), init_ctrl);
  		else
  			writel(card->init_ctrl_value &
  			       ~PC300_CHMEDIA_MASK(port->chan), init_ctrl);
  	}
  }
  
  
  
  static int pc300_open(struct net_device *dev)
  {
  	port_t *port = dev_to_port(dev);
  
  	int result = hdlc_open(dev);
  	if (result)
  		return result;
  
  	sca_open(dev);
  	pc300_set_iface(port);
  	return 0;
  }
  
  
  
  static int pc300_close(struct net_device *dev)
  {
  	sca_close(dev);
  	hdlc_close(dev);
  	return 0;
  }
  
  
  
  static int pc300_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
  {
  	const size_t size = sizeof(sync_serial_settings);
  	sync_serial_settings new_line;
  	sync_serial_settings __user *line = ifr->ifr_settings.ifs_ifsu.sync;
  	int new_type;
  	port_t *port = dev_to_port(dev);
  
  #ifdef DEBUG_RINGS
  	if (cmd == SIOCDEVPRIVATE) {
  		sca_dump_rings(dev);
  		return 0;
  	}
  #endif
  	if (cmd != SIOCWANDEV)
  		return hdlc_ioctl(dev, ifr, cmd);
  
  	if (ifr->ifr_settings.type == IF_GET_IFACE) {
  		ifr->ifr_settings.type = port->iface;
  		if (ifr->ifr_settings.size < size) {
  			ifr->ifr_settings.size = size; /* data size wanted */
  			return -ENOBUFS;
  		}
  		if (copy_to_user(line, &port->settings, size))
  			return -EFAULT;
  		return 0;
  
  	}
  
  	if (port->card->type == PC300_X21 &&
  	    (ifr->ifr_settings.type == IF_IFACE_SYNC_SERIAL ||
  	     ifr->ifr_settings.type == IF_IFACE_X21))
  		new_type = IF_IFACE_X21;
  
  	else if (port->card->type == PC300_RSV &&
  		 (ifr->ifr_settings.type == IF_IFACE_SYNC_SERIAL ||
  		  ifr->ifr_settings.type == IF_IFACE_V35))
  		new_type = IF_IFACE_V35;
  
  	else if (port->card->type == PC300_RSV &&
  		 ifr->ifr_settings.type == IF_IFACE_V24)
  		new_type = IF_IFACE_V24;
  
  	else
  		return hdlc_ioctl(dev, ifr, cmd);
  
  	if (!capable(CAP_NET_ADMIN))
  		return -EPERM;
  
  	if (copy_from_user(&new_line, line, size))
  		return -EFAULT;
  
  	if (new_line.clock_type != CLOCK_EXT &&
  	    new_line.clock_type != CLOCK_TXFROMRX &&
  	    new_line.clock_type != CLOCK_INT &&
  	    new_line.clock_type != CLOCK_TXINT)
  		return -EINVAL;	/* No such clock setting */
  
  	if (new_line.loopback != 0 && new_line.loopback != 1)
  		return -EINVAL;
  
  	memcpy(&port->settings, &new_line, size); /* Update settings */
  	port->iface = new_type;
  	pc300_set_iface(port);
  	return 0;
  }
  
  
  
  static void pc300_pci_remove_one(struct pci_dev *pdev)
  {
  	int i;
  	card_t *card = pci_get_drvdata(pdev);
  
  	for (i = 0; i < 2; i++)
  		if (card->ports[i].card)
  			unregister_hdlc_device(card->ports[i].netdev);
  
  	if (card->irq)
  		free_irq(card->irq, card);
  
  	if (card->rambase)
  		iounmap(card->rambase);
  	if (card->scabase)
  		iounmap(card->scabase);
  	if (card->plxbase)
  		iounmap(card->plxbase);
  
  	pci_release_regions(pdev);
  	pci_disable_device(pdev);
  	if (card->ports[0].netdev)
  		free_netdev(card->ports[0].netdev);
  	if (card->ports[1].netdev)
  		free_netdev(card->ports[1].netdev);
  	kfree(card);
  }
  
  static const struct net_device_ops pc300_ops = {
  	.ndo_open       = pc300_open,
  	.ndo_stop       = pc300_close,
  	.ndo_change_mtu = hdlc_change_mtu,
  	.ndo_start_xmit = hdlc_start_xmit,
  	.ndo_do_ioctl   = pc300_ioctl,
  };
  
  static int pc300_pci_init_one(struct pci_dev *pdev,
  			      const struct pci_device_id *ent)
  {
  	card_t *card;
  	u32 __iomem *p;
  	int i;
  	u32 ramsize;
  	u32 ramphys;		/* buffer memory base */
  	u32 scaphys;		/* SCA memory base */
  	u32 plxphys;		/* PLX registers memory base */
  
  	i = pci_enable_device(pdev);
  	if (i)
  		return i;
  
  	i = pci_request_regions(pdev, "PC300");
  	if (i) {
  		pci_disable_device(pdev);
  		return i;
  	}
  
  	card = kzalloc(sizeof(card_t), GFP_KERNEL);
  	if (card == NULL) {
  		pci_release_regions(pdev);
  		pci_disable_device(pdev);
  		return -ENOBUFS;
  	}
  	pci_set_drvdata(pdev, card);
  
  	if (pci_resource_len(pdev, 0) != PC300_PLX_SIZE ||
  	    pci_resource_len(pdev, 2) != PC300_SCA_SIZE ||
  	    pci_resource_len(pdev, 3) < 16384) {
  		pr_err("invalid card EEPROM parameters
  ");
  		pc300_pci_remove_one(pdev);
  		return -EFAULT;
  	}
  
  	plxphys = pci_resource_start(pdev, 0) & PCI_BASE_ADDRESS_MEM_MASK;
  	card->plxbase = ioremap(plxphys, PC300_PLX_SIZE);
  
  	scaphys = pci_resource_start(pdev, 2) & PCI_BASE_ADDRESS_MEM_MASK;
  	card->scabase = ioremap(scaphys, PC300_SCA_SIZE);
  
  	ramphys = pci_resource_start(pdev, 3) & PCI_BASE_ADDRESS_MEM_MASK;
  	card->rambase = pci_ioremap_bar(pdev, 3);
  
  	if (card->plxbase == NULL ||
  	    card->scabase == NULL ||
  	    card->rambase == NULL) {
  		pr_err("ioremap() failed
  ");
  		pc300_pci_remove_one(pdev);
  	}
  
  	/* PLX PCI 9050 workaround for local configuration register read bug */
  	pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0, scaphys);
  	card->init_ctrl_value = readl(&((plx9050 __iomem *)card->scabase)->init_ctrl);
  	pci_write_config_dword(pdev, PCI_BASE_ADDRESS_0, plxphys);
  
  	if (pdev->device == PCI_DEVICE_ID_PC300_TE_1 ||
  	    pdev->device == PCI_DEVICE_ID_PC300_TE_2)
  		card->type = PC300_TE; /* not fully supported */
  	else if (card->init_ctrl_value & PC300_CTYPE_MASK)
  		card->type = PC300_X21;
  	else
  		card->type = PC300_RSV;
  
  	if (pdev->device == PCI_DEVICE_ID_PC300_RX_1 ||
  	    pdev->device == PCI_DEVICE_ID_PC300_TE_1)
  		card->n_ports = 1;
  	else
  		card->n_ports = 2;
  
  	for (i = 0; i < card->n_ports; i++)
  		if (!(card->ports[i].netdev = alloc_hdlcdev(&card->ports[i]))) {
  			pr_err("unable to allocate memory
  ");
  			pc300_pci_remove_one(pdev);
  			return -ENOMEM;
  		}
  
  	/* Reset PLX */
  	p = &card->plxbase->init_ctrl;
  	writel(card->init_ctrl_value | 0x40000000, p);
  	readl(p);		/* Flush the write - do not use sca_flush */
  	udelay(1);
  
  	writel(card->init_ctrl_value, p);
  	readl(p);		/* Flush the write - do not use sca_flush */
  	udelay(1);
  
  	/* Reload Config. Registers from EEPROM */
  	writel(card->init_ctrl_value | 0x20000000, p);
  	readl(p);		/* Flush the write - do not use sca_flush */
  	udelay(1);
  
  	writel(card->init_ctrl_value, p);
  	readl(p);		/* Flush the write - do not use sca_flush */
  	udelay(1);
  
  	ramsize = sca_detect_ram(card, card->rambase,
  				 pci_resource_len(pdev, 3));
  
  	if (use_crystal_clock)
  		card->init_ctrl_value &= ~PC300_CLKSEL_MASK;
  	else
  		card->init_ctrl_value |= PC300_CLKSEL_MASK;
  
  	writel(card->init_ctrl_value, &card->plxbase->init_ctrl);
  	/* number of TX + RX buffers for one port */
  	i = ramsize / (card->n_ports * (sizeof(pkt_desc) + HDLC_MAX_MRU));
  	card->tx_ring_buffers = min(i / 2, MAX_TX_BUFFERS);
  	card->rx_ring_buffers = i - card->tx_ring_buffers;
  
  	card->buff_offset = card->n_ports * sizeof(pkt_desc) *
  		(card->tx_ring_buffers + card->rx_ring_buffers);
  
  	pr_info("PC300/%s, %u KB RAM at 0x%x, IRQ%u, using %u TX + %u RX packets rings
  ",
  		card->type == PC300_X21 ? "X21" :
  		card->type == PC300_TE ? "TE" : "RSV",
  		ramsize / 1024, ramphys, pdev->irq,
  		card->tx_ring_buffers, card->rx_ring_buffers);
  
  	if (card->tx_ring_buffers < 1) {
  		pr_err("RAM test failed
  ");
  		pc300_pci_remove_one(pdev);
  		return -EFAULT;
  	}
  
  	/* Enable interrupts on the PCI bridge, LINTi1 active low */
  	writew(0x0041, &card->plxbase->intr_ctrl_stat);
  
  	/* Allocate IRQ */
  	if (request_irq(pdev->irq, sca_intr, IRQF_SHARED, "pc300", card)) {
  		pr_warn("could not allocate IRQ%d
  ", pdev->irq);
  		pc300_pci_remove_one(pdev);
  		return -EBUSY;
  	}
  	card->irq = pdev->irq;
  
  	sca_init(card, 0);
  
  	// COTE not set - allows better TX DMA settings
  	// sca_out(sca_in(PCR, card) | PCR_COTE, PCR, card);
  
  	sca_out(0x10, BTCR, card);
  
  	for (i = 0; i < card->n_ports; i++) {
  		port_t *port = &card->ports[i];
  		struct net_device *dev = port->netdev;
  		hdlc_device *hdlc = dev_to_hdlc(dev);
  		port->chan = i;
  
  		spin_lock_init(&port->lock);
  		dev->irq = card->irq;
  		dev->mem_start = ramphys;
  		dev->mem_end = ramphys + ramsize - 1;
  		dev->tx_queue_len = 50;
  		dev->netdev_ops = &pc300_ops;
  		hdlc->attach = sca_attach;
  		hdlc->xmit = sca_xmit;
  		port->settings.clock_type = CLOCK_EXT;
  		port->card = card;
  		if (card->type == PC300_X21)
  			port->iface = IF_IFACE_X21;
  		else
  			port->iface = IF_IFACE_V35;
  
  		sca_init_port(port);
  		if (register_hdlc_device(dev)) {
  			pr_err("unable to register hdlc device
  ");
  			port->card = NULL;
  			pc300_pci_remove_one(pdev);
  			return -ENOBUFS;
  		}
  
  		netdev_info(dev, "PC300 channel %d
  ", port->chan);
  	}
  	return 0;
  }
  
  
  
  static DEFINE_PCI_DEVICE_TABLE(pc300_pci_tbl) = {
  	{ PCI_VENDOR_ID_CYCLADES, PCI_DEVICE_ID_PC300_RX_1, PCI_ANY_ID,
  	  PCI_ANY_ID, 0, 0, 0 },
  	{ PCI_VENDOR_ID_CYCLADES, PCI_DEVICE_ID_PC300_RX_2, PCI_ANY_ID,
  	  PCI_ANY_ID, 0, 0, 0 },
  	{ PCI_VENDOR_ID_CYCLADES, PCI_DEVICE_ID_PC300_TE_1, PCI_ANY_ID,
  	  PCI_ANY_ID, 0, 0, 0 },
  	{ PCI_VENDOR_ID_CYCLADES, PCI_DEVICE_ID_PC300_TE_2, PCI_ANY_ID,
  	  PCI_ANY_ID, 0, 0, 0 },
  	{ 0, }
  };
  
  
  static struct pci_driver pc300_pci_driver = {
  	.name =          "PC300",
  	.id_table =      pc300_pci_tbl,
  	.probe =         pc300_pci_init_one,
  	.remove =        pc300_pci_remove_one,
  };
  
  
  static int __init pc300_init_module(void)
  {
  	if (pci_clock_freq < 1000000 || pci_clock_freq > 80000000) {
  		pr_err("Invalid PCI clock frequency
  ");
  		return -EINVAL;
  	}
  	if (use_crystal_clock != 0 && use_crystal_clock != 1) {
  		pr_err("Invalid 'use_crystal_clock' value
  ");
  		return -EINVAL;
  	}
  
  	CLOCK_BASE = use_crystal_clock ? 24576000 : pci_clock_freq;
  
  	return pci_register_driver(&pc300_pci_driver);
  }
  
  
  
  static void __exit pc300_cleanup_module(void)
  {
  	pci_unregister_driver(&pc300_pci_driver);
  }
  
  MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
  MODULE_DESCRIPTION("Cyclades PC300 serial port driver");
  MODULE_LICENSE("GPL v2");
  MODULE_DEVICE_TABLE(pci, pc300_pci_tbl);
  module_param(pci_clock_freq, int, 0444);
  MODULE_PARM_DESC(pci_clock_freq, "System PCI clock frequency in Hz");
  module_param(use_crystal_clock, int, 0444);
  MODULE_PARM_DESC(use_crystal_clock,
  		 "Use 24.576 MHz clock instead of PCI clock");
  module_init(pc300_init_module);
  module_exit(pc300_cleanup_module);