/*
 * URB OHCI HCD (Host Controller Driver) for USB.
 * 
 * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
 * (C) Copyright 2000-2001 David Brownell <dbrownell@users.sourceforge.net>
 * 
 * usb-ohci.h
 */

 
static int cc_to_error[16] = { 

/* mapping of the OHCI CC status to error codes */ 
	/* No  Error  */	0,
	/* CRC Error  */	-EILSEQ,
	/* Bit Stuff  */	-EPROTO,
	/* Data Togg  */	-EILSEQ,
	/* Stall      */	-EPIPE,
	/* DevNotResp */	-ETIMEDOUT,
	/* PIDCheck   */	-EPROTO,
	/* UnExpPID   */	-EPROTO,
	/* DataOver   */	-EOVERFLOW,
	/* DataUnder  */	-EREMOTEIO,
	/* reservd    */	-ETIMEDOUT,
	/* reservd    */	-ETIMEDOUT,
	/* BufferOver */	-ECOMM,
	/* BuffUnder  */	-ENOSR,
	/* Not Access */	-ETIMEDOUT,
	/* Not Access */	-ETIMEDOUT 
};

#include <linux/config.h>

/* ED States */

#define ED_NEW 		0x00
#define ED_UNLINK 	0x01
#define ED_OPER		0x02
#define ED_DEL		0x04
#define ED_URB_DEL  	0x08

/* usb_ohci_ed */
struct ed {
	__u32 hwINFO;       
	__u32 hwTailP;
	__u32 hwHeadP;
	__u32 hwNextED;

	struct ed * ed_prev;  
	__u8 int_period;
	__u8 int_branch;
	__u8 int_load; 
	__u8 int_interval;
	__u8 state;
	__u8 type; 
	__u16 last_iso;
	struct ed * ed_rm_list;

	dma_addr_t dma;
	__u32 unused[3];
} __attribute((aligned(16)));
typedef struct ed ed_t;

 
/* TD info field */
#define TD_CC       0xf0000000
#define TD_CC_GET(td_p) ((td_p >>28) & 0x0f)
#define TD_CC_SET(td_p, cc) (td_p) = ((td_p) & 0x0fffffff) | (((cc) & 0x0f) << 28)
#define TD_EC       0x0C000000
#define TD_T        0x03000000
#define TD_T_DATA0  0x02000000
#define TD_T_DATA1  0x03000000
#define TD_T_TOGGLE 0x00000000
#define TD_R        0x00040000
#define TD_DI       0x00E00000
#define TD_DI_SET(X) (((X) & 0x07)<< 21)
#define TD_DP       0x00180000
#define TD_DP_SETUP 0x00000000
#define TD_DP_IN    0x00100000
#define TD_DP_OUT   0x00080000

#define TD_ISO	    0x00010000
#define TD_DEL      0x00020000

/* CC Codes */
#define TD_CC_NOERROR      0x00
#define TD_CC_CRC          0x01
#define TD_CC_BITSTUFFING  0x02
#define TD_CC_DATATOGGLEM  0x03
#define TD_CC_STALL        0x04
#define TD_DEVNOTRESP      0x05
#define TD_PIDCHECKFAIL    0x06
#define TD_UNEXPECTEDPID   0x07
#define TD_DATAOVERRUN     0x08
#define TD_DATAUNDERRUN    0x09
#define TD_BUFFEROVERRUN   0x0C
#define TD_BUFFERUNDERRUN  0x0D
#define TD_NOTACCESSED     0x0F


#define MAXPSW 1

struct td {
	__u32 hwINFO;
  	__u32 hwCBP;		/* Current Buffer Pointer */
  	__u32 hwNextTD;		/* Next TD Pointer */
  	__u32 hwBE;		/* Memory Buffer End Pointer */

  	__u16 hwPSW[MAXPSW];
  	__u8 unused;
  	__u8 index;
  	struct ed * ed;
  	struct td * next_dl_td;
  	struct urb * urb;

	dma_addr_t td_dma;
	dma_addr_t data_dma;
	__u32 unused2[2];
} __attribute((aligned(32)));	/* normally 16, iso needs 32 */
typedef struct td td_t;

#define OHCI_ED_SKIP	(1 << 14)

/*
 * The HCCA (Host Controller Communications Area) is a 256 byte
 * structure defined in the OHCI spec. that the host controller is
 * told the base address of.  It must be 256-byte aligned.
 */
 
#define NUM_INTS 32	/* part of the OHCI standard */
struct ohci_hcca {
	__u32	int_table[NUM_INTS];	/* Interrupt ED table */
	__u16	frame_no;		/* current frame number */
	__u16	pad1;			/* set to 0 on each frame_no change */
	__u32	done_head;		/* info returned for an interrupt */
	u8		reserved_for_hc[116];
} __attribute((aligned(256)));

  
/*
 * Maximum number of root hub ports.  
 */
#define MAX_ROOT_PORTS	15	/* maximum OHCI root hub ports */

/*
 * This is the structure of the OHCI controller's memory mapped I/O
 * region.  This is Memory Mapped I/O.  You must use the readl() and
 * writel() macros defined in asm/io.h to access these!!
 */
struct ohci_regs {
	/* control and status registers */
	__u32	revision;
	__u32	control;
	__u32	cmdstatus;
	__u32	intrstatus;
	__u32	intrenable;
	__u32	intrdisable;
	/* memory pointers */
	__u32	hcca;
	__u32	ed_periodcurrent;
	__u32	ed_controlhead;
	__u32	ed_controlcurrent;
	__u32	ed_bulkhead;
	__u32	ed_bulkcurrent;
	__u32	donehead;
	/* frame counters */
	__u32	fminterval;
	__u32	fmremaining;
	__u32	fmnumber;
	__u32	periodicstart;
	__u32	lsthresh;
	/* Root hub ports */
	struct	ohci_roothub_regs {
		__u32	a;
		__u32	b;
		__u32	status;
		__u32	portstatus[MAX_ROOT_PORTS];
	} roothub;
} __attribute((aligned(32)));


/* OHCI CONTROL AND STATUS REGISTER MASKS */

/*
 * HcControl (control) register masks
 */
#define OHCI_CTRL_CBSR	(3 << 0)	/* control/bulk service ratio */
#define OHCI_CTRL_PLE	(1 << 2)	/* periodic list enable */
#define OHCI_CTRL_IE	(1 << 3)	/* isochronous enable */
#define OHCI_CTRL_CLE	(1 << 4)	/* control list enable */
#define OHCI_CTRL_BLE	(1 << 5)	/* bulk list enable */
#define OHCI_CTRL_HCFS	(3 << 6)	/* host controller functional state */
#define OHCI_CTRL_IR	(1 << 8)	/* interrupt routing */
#define OHCI_CTRL_RWC	(1 << 9)	/* remote wakeup connected */
#define OHCI_CTRL_RWE	(1 << 10)	/* remote wakeup enable */

/* pre-shifted values for HCFS */
#	define OHCI_USB_RESET	(0 << 6)
#	define OHCI_USB_RESUME	(1 << 6)
#	define OHCI_USB_OPER	(2 << 6)
#	define OHCI_USB_SUSPEND	(3 << 6)

/*
 * HcCommandStatus (cmdstatus) register masks
 */
#define OHCI_HCR	(1 << 0)	/* host controller reset */
#define OHCI_CLF  	(1 << 1)	/* control list filled */
#define OHCI_BLF  	(1 << 2)	/* bulk list filled */
#define OHCI_OCR  	(1 << 3)	/* ownership change request */
#define OHCI_SOC  	(3 << 16)	/* scheduling overrun count */

/*
 * masks used with interrupt registers:
 * HcInterruptStatus (intrstatus)
 * HcInterruptEnable (intrenable)
 * HcInterruptDisable (intrdisable)
 */
#define OHCI_INTR_SO	(1 << 0)	/* scheduling overrun */
#define OHCI_INTR_WDH	(1 << 1)	/* writeback of done_head */
#define OHCI_INTR_SF	(1 << 2)	/* start frame */
#define OHCI_INTR_RD	(1 << 3)	/* resume detect */
#define OHCI_INTR_UE	(1 << 4)	/* unrecoverable error */
#define OHCI_INTR_FNO	(1 << 5)	/* frame number overflow */
#define OHCI_INTR_RHSC	(1 << 6)	/* root hub status change */
#define OHCI_INTR_OC	(1 << 30)	/* ownership change */
#define OHCI_INTR_MIE	(1 << 31)	/* master interrupt enable */



/* Virtual Root HUB */
struct virt_root_hub {
	int devnum; /* Address of Root Hub endpoint */ 
	void * urb;
	void * int_addr;
	int send;
	int interval;
	struct timer_list rh_int_timer;
};


/* USB HUB CONSTANTS (not OHCI-specific; see hub.h) */
 
/* destination of request */
#define RH_INTERFACE               0x01
#define RH_ENDPOINT                0x02
#define RH_OTHER                   0x03

#define RH_CLASS                   0x20
#define RH_VENDOR                  0x40

/* Requests: bRequest << 8 | bmRequestType */
#define RH_GET_STATUS           0x0080
#define RH_CLEAR_FEATURE        0x0100
#define RH_SET_FEATURE          0x0300
#define RH_SET_ADDRESS		0x0500
#define RH_GET_DESCRIPTOR	0x0680
#define RH_SET_DESCRIPTOR       0x0700
#define RH_GET_CONFIGURATION	0x0880
#define RH_SET_CONFIGURATION	0x0900
#define RH_GET_STATE            0x0280
#define RH_GET_INTERFACE        0x0A80
#define RH_SET_INTERFACE        0x0B00
#define RH_SYNC_FRAME           0x0C80
/* Our Vendor Specific Request */
#define RH_SET_EP               0x2000


/* Hub port features */
#define RH_PORT_CONNECTION         0x00
#define RH_PORT_ENABLE             0x01
#define RH_PORT_SUSPEND            0x02
#define RH_PORT_OVER_CURRENT       0x03
#define RH_PORT_RESET              0x04
#define RH_PORT_POWER              0x08
#define RH_PORT_LOW_SPEED          0x09

#define RH_C_PORT_CONNECTION       0x10
#define RH_C_PORT_ENABLE           0x11
#define RH_C_PORT_SUSPEND          0x12
#define RH_C_PORT_OVER_CURRENT     0x13
#define RH_C_PORT_RESET            0x14  

/* Hub features */
#define RH_C_HUB_LOCAL_POWER       0x00
#define RH_C_HUB_OVER_CURRENT      0x01

#define RH_DEVICE_REMOTE_WAKEUP    0x00
#define RH_ENDPOINT_STALL          0x01

#define RH_ACK                     0x01
#define RH_REQ_ERR                 -1
#define RH_NACK                    0x00


/* OHCI ROOT HUB REGISTER MASKS */
 
/* roothub.portstatus [i] bits */
#define RH_PS_CCS            0x00000001   	/* current connect status */
#define RH_PS_PES            0x00000002   	/* port enable status*/
#define RH_PS_PSS            0x00000004   	/* port suspend status */
#define RH_PS_POCI           0x00000008   	/* port over current indicator */
#define RH_PS_PRS            0x00000010  	/* port reset status */
#define RH_PS_PPS            0x00000100   	/* port power status */
#define RH_PS_LSDA           0x00000200    	/* low speed device attached */
#define RH_PS_CSC            0x00010000 	/* connect status change */
#define RH_PS_PESC           0x00020000   	/* port enable status change */
#define RH_PS_PSSC           0x00040000    	/* port suspend status change */
#define RH_PS_OCIC           0x00080000    	/* over current indicator change */
#define RH_PS_PRSC           0x00100000   	/* port reset status change */

/* roothub.status bits */
#define RH_HS_LPS	     0x00000001		/* local power status */
#define RH_HS_OCI	     0x00000002		/* over current indicator */
#define RH_HS_DRWE	     0x00008000		/* device remote wakeup enable */
#define RH_HS_LPSC	     0x00010000		/* local power status change */
#define RH_HS_OCIC	     0x00020000		/* over current indicator change */
#define RH_HS_CRWE	     0x80000000		/* clear remote wakeup enable */

/* roothub.b masks */
#define RH_B_DR		0x0000ffff		/* device removable flags */
#define RH_B_PPCM	0xffff0000		/* port power control mask */

/* roothub.a masks */
#define	RH_A_NDP	(0xff << 0)		/* number of downstream ports */
#define	RH_A_PSM	(1 << 8)		/* power switching mode */
#define	RH_A_NPS	(1 << 9)		/* no power switching */
#define	RH_A_DT		(1 << 10)		/* device type (mbz) */
#define	RH_A_OCPM	(1 << 11)		/* over current protection mode */
#define	RH_A_NOCP	(1 << 12)		/* no over current protection */
#define	RH_A_POTPGT	(0xff << 24)		/* power on to power good time */

/* urb */
typedef struct 
{
	ed_t * ed;
	__u16 length;	// number of tds associated with this request
	__u16 td_cnt;	// number of tds already serviced
	int   state;
	wait_queue_head_t * wait;
	td_t * td[0];	// list pointer to all corresponding TDs associated with this request

} urb_priv_t;
#define URB_DEL 1


/* Hash struct used for TD/ED hashing */
struct hash_t {
	void		*virt;
	dma_addr_t	dma;
	struct hash_t	*next; // chaining for collision cases
};

/* List of TD/ED hash entries */
struct hash_list_t {
	struct hash_t	*head;
	struct hash_t	*tail;
};

#define TD_HASH_SIZE    64    /* power'o'two */
#define ED_HASH_SIZE    64    /* power'o'two */

#define TD_HASH_FUNC(td_dma) ((td_dma ^ (td_dma >> 5)) % TD_HASH_SIZE)
#define ED_HASH_FUNC(ed_dma) ((ed_dma ^ (ed_dma >> 5)) % ED_HASH_SIZE)


/*
 * This is the full ohci controller description
 *
 * Note how the "proper" USB information is just
 * a subset of what the full implementation needs. (Linus)
 */


typedef struct ohci {
	struct ohci_hcca *hcca;		/* hcca */
	dma_addr_t hcca_dma;

	int irq;
	int disabled;			/* e.g. got a UE, we're hung */
	int sleeping;
	atomic_t resume_count;		/* defending against multiple resumes */
	unsigned long flags;		/* for HC bugs */
#define	OHCI_QUIRK_AMD756	0x01		/* erratum #4 */

	struct ohci_regs * regs;	/* OHCI controller's memory */
	struct list_head ohci_hcd_list;	/* list of all ohci_hcd */

	struct ohci * next; 		// chain of ohci device contexts
	struct list_head timeout_list;
	// struct list_head urb_list; 	// list of all pending urbs
	// spinlock_t urb_list_lock; 	// lock to keep consistency 
  
	int ohci_int_load[32];		/* load of the 32 Interrupt Chains (for load balancing)*/
	ed_t * ed_rm_list[2];     /* lists of all endpoints to be removed */
	ed_t * ed_bulktail;       /* last endpoint of bulk list */
	ed_t * ed_controltail;    /* last endpoint of control list */
 	ed_t * ed_isotail;        /* last endpoint of iso list */
	int intrstatus;
	__u32 hc_control;		/* copy of the hc control reg */
	struct usb_bus * bus;    
	struct usb_device * dev[128];
	struct virt_root_hub rh;

	/* PCI device handle, settings, ... */
	struct pci_dev	*ohci_dev;
	u8		pci_latency;
	struct pci_pool	*td_cache;
	struct pci_pool	*dev_cache;
	struct hash_list_t	td_hash[TD_HASH_SIZE];
	struct hash_list_t	ed_hash[ED_HASH_SIZE];

} ohci_t;

#define NUM_EDS 32		/* num of preallocated endpoint descriptors */

struct ohci_device {
	ed_t 	ed[NUM_EDS];
	dma_addr_t dma;
	int ed_cnt;
	wait_queue_head_t * wait;
};

// #define ohci_to_usb(ohci)	((ohci)->usb)
#define usb_to_ohci(usb)	((struct ohci_device *)(usb)->hcpriv)

/* hcd */
/* endpoint */
static int ep_link(ohci_t * ohci, ed_t * ed);
static int ep_unlink(ohci_t * ohci, ed_t * ed);
static ed_t * ep_add_ed(struct usb_device * usb_dev, unsigned int pipe, int interval, int load, int mem_flags);
static void ep_rm_ed(struct usb_device * usb_dev, ed_t * ed);
/* td */
static void td_fill(ohci_t * ohci, unsigned int info, dma_addr_t data, int len, struct urb * urb, int index);
static void td_submit_urb(struct urb * urb);
/* root hub */
static int rh_submit_urb(struct urb * urb);
static int rh_unlink_urb(struct urb * urb);
static int rh_init_int_timer(struct urb * urb);

/*-------------------------------------------------------------------------*/

#define ALLOC_FLAGS (in_interrupt () ? GFP_ATOMIC : GFP_KERNEL)

#ifdef DEBUG
#	define OHCI_MEM_FLAGS	SLAB_POISON
#else
#	define OHCI_MEM_FLAGS	0
#endif
 
#ifndef CONFIG_PCI
#	error "usb-ohci currently requires PCI-based controllers"
	/* to support non-PCI OHCIs, you need custom bus/mem/... glue */
#endif


/* Recover a TD/ED using its collision chain */
static void *
dma_to_ed_td (struct hash_list_t * entry, dma_addr_t dma)
{
	struct hash_t * scan = entry->head;
	while (scan && scan->dma != dma)
		scan = scan->next;
	if (!scan)
		BUG();
	return scan->virt;
}

static struct ed *
dma_to_ed (struct ohci * hc, dma_addr_t ed_dma)
{
	return (struct ed *) dma_to_ed_td(&(hc->ed_hash[ED_HASH_FUNC(ed_dma)]),
				      ed_dma);
}

static struct td *
dma_to_td (struct ohci * hc, dma_addr_t td_dma)
{
	return (struct td *) dma_to_ed_td(&(hc->td_hash[TD_HASH_FUNC(td_dma)]),
				      td_dma);
}

/* Add a hash entry for a TD/ED; return true on success */
static int
hash_add_ed_td(struct hash_list_t * entry, void * virt, dma_addr_t dma)
{
	struct hash_t * scan;
	
	scan = (struct hash_t *)kmalloc(sizeof(struct hash_t), ALLOC_FLAGS);
	if (!scan)
		return 0;
	
	if (!entry->tail) {
		entry->head = entry->tail = scan;
	} else {
		entry->tail->next = scan;
		entry->tail = scan;
	}
	
	scan->virt = virt;
	scan->dma = dma;
	scan->next = NULL;
	return 1;
}

static int
hash_add_ed (struct ohci * hc, struct ed * ed)
{
	return hash_add_ed_td (&(hc->ed_hash[ED_HASH_FUNC(ed->dma)]),
			ed, ed->dma);
}

static int
hash_add_td (struct ohci * hc, struct td * td)
{
	return hash_add_ed_td (&(hc->td_hash[TD_HASH_FUNC(td->td_dma)]),
			td, td->td_dma);
}


static void
hash_free_ed_td (struct hash_list_t * entry, void * virt)
{
	struct hash_t *scan, *prev;
	scan = prev = entry->head;

	// Find and unlink hash entry
	while (scan && scan->virt != virt) {
		prev = scan;
		scan = scan->next;
	}
	if (scan) {
		if (scan == entry->head) {
			if (entry->head == entry->tail)
				entry->head = entry->tail = NULL;
			else
				entry->head = scan->next;
		} else if (scan == entry->tail) {
			entry->tail = prev;
			prev->next = NULL;
		} else
			prev->next = scan->next;
		kfree(scan);
	}
}

static void
hash_free_ed (struct ohci * hc, struct ed * ed)
{
	hash_free_ed_td (&(hc->ed_hash[ED_HASH_FUNC(ed->dma)]), ed);
}

static void
hash_free_td (struct ohci * hc, struct td * td)
{
	hash_free_ed_td (&(hc->td_hash[TD_HASH_FUNC(td->td_dma)]), td);
}


static int ohci_mem_init (struct ohci *ohci)
{
	ohci->td_cache = pci_pool_create ("ohci_td", ohci->ohci_dev,
		sizeof (struct td),
		32 /* byte alignment */,
		0 /* no page-crossing issues */,
		GFP_KERNEL | OHCI_MEM_FLAGS);
	if (!ohci->td_cache)
		return -ENOMEM;
	ohci->dev_cache = pci_pool_create ("ohci_dev", ohci->ohci_dev,
		sizeof (struct ohci_device),
		16 /* byte alignment */,
		0 /* no page-crossing issues */,
		GFP_KERNEL | OHCI_MEM_FLAGS);
	if (!ohci->dev_cache)
		return -ENOMEM;
	return 0;
}

static void ohci_mem_cleanup (struct ohci *ohci)
{
	if (ohci->td_cache) {
		pci_pool_destroy (ohci->td_cache);
		ohci->td_cache = 0;
	}
	if (ohci->dev_cache) {
		pci_pool_destroy (ohci->dev_cache);
		ohci->dev_cache = 0;
	}
}

/* TDs ... */
static struct td *
td_alloc (struct ohci *hc, int mem_flags)
{
	dma_addr_t	dma;
	struct td	*td;

	td = pci_pool_alloc (hc->td_cache, mem_flags, &dma);
	if (td) {
		td->td_dma = dma;

		/* hash it for later reverse mapping */
		if (!hash_add_td (hc, td)) {
			pci_pool_free (hc->td_cache, td, dma);
			return NULL;
		}
	}
	return td;
}

static inline void
td_free (struct ohci *hc, struct td *td)
{
	hash_free_td (hc, td);
	pci_pool_free (hc->td_cache, td, td->td_dma);
}


/* DEV + EDs ... only the EDs need to be consistent */
static struct ohci_device *
dev_alloc (struct ohci *hc, int mem_flags)
{
	dma_addr_t		dma;
	struct ohci_device	*dev;
	int			i, offset;

	dev = pci_pool_alloc (hc->dev_cache, mem_flags, &dma);
	if (dev) {
		memset (dev, 0, sizeof (*dev));
		dev->dma = dma;
		offset = ((char *)&dev->ed) - ((char *)dev);
		for (i = 0; i < NUM_EDS; i++, offset += sizeof dev->ed [0])
			dev->ed [i].dma = dma + offset;
		/* add to hashtable if used */
	}
	return dev;
}

static inline void
dev_free (struct ohci *hc, struct ohci_device *dev)
{
	pci_pool_free (hc->dev_cache, dev, dev->dma);
}