parport_ip32.c

linux 内核源代码

		parport_ip32_write_econtrol(p, ecr);
	}
	parport_ip32_write_econtrol(p, mode | ECR_nERRINTR | ECR_SERVINTR);
}

/*--- Basic functions needed for parport -------------------------------*/

/**
 * parport_ip32_read_data - return current contents of the DATA register
 * @p:		pointer to &struct parport
 */
static inline unsigned char parport_ip32_read_data(struct parport *p)
{
	struct parport_ip32_private * const priv = p->physport->private_data;
	return readb(priv->regs.data);
}

/**
 * parport_ip32_write_data - set new contents for the DATA register
 * @p:		pointer to &struct parport
 * @d:		new value to write
 */
static inline void parport_ip32_write_data(struct parport *p, unsigned char d)
{
	struct parport_ip32_private * const priv = p->physport->private_data;
	writeb(d, priv->regs.data);
}

/**
 * parport_ip32_read_status - return current contents of the DSR register
 * @p:		pointer to &struct parport
 */
static inline unsigned char parport_ip32_read_status(struct parport *p)
{
	struct parport_ip32_private * const priv = p->physport->private_data;
	return readb(priv->regs.dsr);
}

/**
 * __parport_ip32_read_control - return cached contents of the DCR register
 * @p:		pointer to &struct parport
 */
static inline unsigned int __parport_ip32_read_control(struct parport *p)
{
	struct parport_ip32_private * const priv = p->physport->private_data;
	return priv->dcr_cache; /* use soft copy */
}

/**
 * __parport_ip32_write_control - set new contents for the DCR register
 * @p:		pointer to &struct parport
 * @c:		new value to write
 */
static inline void __parport_ip32_write_control(struct parport *p,
						unsigned int c)
{
	struct parport_ip32_private * const priv = p->physport->private_data;
	CHECK_EXTRA_BITS(p, c, priv->dcr_writable);
	c &= priv->dcr_writable; /* only writable bits */
	writeb(c, priv->regs.dcr);
	priv->dcr_cache = c;		/* update soft copy */
}

/**
 * __parport_ip32_frob_control - change bits from the DCR register
 * @p:		pointer to &struct parport
 * @mask:	bit mask of bits to change
 * @val:	new value for changed bits
 *
 * This is equivalent to read from the DCR, mask out the bits in @mask,
 * exclusive-or with the bits in @val, and write the result to the DCR.
 * Actually, the cached contents of the DCR is used.
 */
static inline void __parport_ip32_frob_control(struct parport *p,
					       unsigned int mask,
					       unsigned int val)
{
	unsigned int c;
	c = (__parport_ip32_read_control(p) & ~mask) ^ val;
	__parport_ip32_write_control(p, c);
}

/**
 * parport_ip32_read_control - return cached contents of the DCR register
 * @p:		pointer to &struct parport
 *
 * The return value is masked so as to only return the value of %DCR_STROBE,
 * %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
 */
static inline unsigned char parport_ip32_read_control(struct parport *p)
{
	const unsigned int rm =
		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
	return __parport_ip32_read_control(p) & rm;
}

/**
 * parport_ip32_write_control - set new contents for the DCR register
 * @p:		pointer to &struct parport
 * @c:		new value to write
 *
 * The value is masked so as to only change the value of %DCR_STROBE,
 * %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
 */
static inline void parport_ip32_write_control(struct parport *p,
					      unsigned char c)
{
	const unsigned int wm =
		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
	CHECK_EXTRA_BITS(p, c, wm);
	__parport_ip32_frob_control(p, wm, c & wm);
}

/**
 * parport_ip32_frob_control - change bits from the DCR register
 * @p:		pointer to &struct parport
 * @mask:	bit mask of bits to change
 * @val:	new value for changed bits
 *
 * This differs from __parport_ip32_frob_control() in that it only allows to
 * change the value of %DCR_STROBE, %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
 */
static inline unsigned char parport_ip32_frob_control(struct parport *p,
						      unsigned char mask,
						      unsigned char val)
{
	const unsigned int wm =
		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
	CHECK_EXTRA_BITS(p, mask, wm);
	CHECK_EXTRA_BITS(p, val, wm);
	__parport_ip32_frob_control(p, mask & wm, val & wm);
	return parport_ip32_read_control(p);
}

/**
 * parport_ip32_disable_irq - disable interrupts on the rising edge of nACK
 * @p:		pointer to &struct parport
 */
static inline void parport_ip32_disable_irq(struct parport *p)
{
	__parport_ip32_frob_control(p, DCR_IRQ, 0);
}

/**
 * parport_ip32_enable_irq - enable interrupts on the rising edge of nACK
 * @p:		pointer to &struct parport
 */
static inline void parport_ip32_enable_irq(struct parport *p)
{
	__parport_ip32_frob_control(p, DCR_IRQ, DCR_IRQ);
}

/**
 * parport_ip32_data_forward - enable host-to-peripheral communications
 * @p:		pointer to &struct parport
 *
 * Enable the data line drivers, for 8-bit host-to-peripheral communications.
 */
static inline void parport_ip32_data_forward(struct parport *p)
{
	__parport_ip32_frob_control(p, DCR_DIR, 0);
}

/**
 * parport_ip32_data_reverse - enable peripheral-to-host communications
 * @p:		pointer to &struct parport
 *
 * Place the data bus in a high impedance state, if @p->modes has the
 * PARPORT_MODE_TRISTATE bit set.
 */
static inline void parport_ip32_data_reverse(struct parport *p)
{
	__parport_ip32_frob_control(p, DCR_DIR, DCR_DIR);
}

/**
 * parport_ip32_init_state - for core parport code
 * @dev:	pointer to &struct pardevice
 * @s:		pointer to &struct parport_state to initialize
 */
static void parport_ip32_init_state(struct pardevice *dev,
				    struct parport_state *s)
{
	s->u.ip32.dcr = DCR_SELECT | DCR_nINIT;
	s->u.ip32.ecr = ECR_MODE_PS2 | ECR_nERRINTR | ECR_SERVINTR;
}

/**
 * parport_ip32_save_state - for core parport code
 * @p:		pointer to &struct parport
 * @s:		pointer to &struct parport_state to save state to
 */
static void parport_ip32_save_state(struct parport *p,
				    struct parport_state *s)
{
	s->u.ip32.dcr = __parport_ip32_read_control(p);
	s->u.ip32.ecr = parport_ip32_read_econtrol(p);
}

/**
 * parport_ip32_restore_state - for core parport code
 * @p:		pointer to &struct parport
 * @s:		pointer to &struct parport_state to restore state from
 */
static void parport_ip32_restore_state(struct parport *p,
				       struct parport_state *s)
{
	parport_ip32_set_mode(p, s->u.ip32.ecr & ECR_MODE_MASK);
	parport_ip32_write_econtrol(p, s->u.ip32.ecr);
	__parport_ip32_write_control(p, s->u.ip32.dcr);
}

/*--- EPP mode functions -----------------------------------------------*/

/**
 * parport_ip32_clear_epp_timeout - clear Timeout bit in EPP mode
 * @p:		pointer to &struct parport
 *
 * Returns 1 if the Timeout bit is clear, and 0 otherwise.
 */
static unsigned int parport_ip32_clear_epp_timeout(struct parport *p)
{
	struct parport_ip32_private * const priv = p->physport->private_data;
	unsigned int cleared;

	if (!(parport_ip32_read_status(p) & DSR_TIMEOUT))
		cleared = 1;
	else {
		unsigned int r;
		/* To clear timeout some chips require double read */
		parport_ip32_read_status(p);
		r = parport_ip32_read_status(p);
		/* Some reset by writing 1 */
		writeb(r | DSR_TIMEOUT, priv->regs.dsr);
		/* Others by writing 0 */
		writeb(r & ~DSR_TIMEOUT, priv->regs.dsr);

		r = parport_ip32_read_status(p);
		cleared = !(r & DSR_TIMEOUT);
	}

	pr_trace(p, "(): %s", cleared ? "cleared" : "failed");
	return cleared;
}

/**
 * parport_ip32_epp_read - generic EPP read function
 * @eppreg:	I/O register to read from
 * @p:		pointer to &struct parport
 * @buf:	buffer to store read data
 * @len:	length of buffer @buf
 * @flags:	may be PARPORT_EPP_FAST
 */
static size_t parport_ip32_epp_read(void __iomem *eppreg,
				    struct parport *p, void *buf,
				    size_t len, int flags)
{
	struct parport_ip32_private * const priv = p->physport->private_data;
	size_t got;
	parport_ip32_set_mode(p, ECR_MODE_EPP);
	parport_ip32_data_reverse(p);
	parport_ip32_write_control(p, DCR_nINIT);
	if ((flags & PARPORT_EPP_FAST) && (len > 1)) {
		readsb(eppreg, buf, len);
		if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
			parport_ip32_clear_epp_timeout(p);
			return -EIO;
		}
		got = len;
	} else {
		u8 *bufp = buf;
		for (got = 0; got < len; got++) {
			*bufp++ = readb(eppreg);
			if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
				parport_ip32_clear_epp_timeout(p);
				break;
			}
		}
	}
	parport_ip32_data_forward(p);
	parport_ip32_set_mode(p, ECR_MODE_PS2);
	return got;
}

/**
 * parport_ip32_epp_write - generic EPP write function
 * @eppreg:	I/O register to write to
 * @p:		pointer to &struct parport
 * @buf:	buffer of data to write
 * @len:	length of buffer @buf
 * @flags:	may be PARPORT_EPP_FAST
 */
static size_t parport_ip32_epp_write(void __iomem *eppreg,
				     struct parport *p, const void *buf,
				     size_t len, int flags)
{
	struct parport_ip32_private * const priv = p->physport->private_data;
	size_t written;
	parport_ip32_set_mode(p, ECR_MODE_EPP);
	parport_ip32_data_forward(p);
	parport_ip32_write_control(p, DCR_nINIT);
	if ((flags & PARPORT_EPP_FAST) && (len > 1)) {
		writesb(eppreg, buf, len);
		if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
			parport_ip32_clear_epp_timeout(p);
			return -EIO;
		}
		written = len;
	} else {
		const u8 *bufp = buf;
		for (written = 0; written < len; written++) {
			writeb(*bufp++, eppreg);
			if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
				parport_ip32_clear_epp_timeout(p);
				break;
			}
		}
	}
	parport_ip32_set_mode(p, ECR_MODE_PS2);
	return written;
}

/**
 * parport_ip32_epp_read_data - read a block of data in EPP mode
 * @p:		pointer to &struct parport
 * @buf:	buffer to store read data
 * @len:	length of buffer @buf
 * @flags:	may be PARPORT_EPP_FAST
 */
static size_t parport_ip32_epp_read_data(struct parport *p, void *buf,
					 size_t len, int flags)
{
	struct parport_ip32_private * const priv = p->physport->private_data;
	return parport_ip32_epp_read(priv->regs.eppData0, p, buf, len, flags);
}

/**
 * parport_ip32_epp_write_data - write a block of data in EPP mode
 * @p:		pointer to &struct parport
 * @buf:	buffer of data to write
 * @len:	length of buffer @buf
 * @flags:	may be PARPORT_EPP_FAST
 */
static size_t parport_ip32_epp_write_data(struct parport *p, const void *buf,
					  size_t len, int flags)
{
	struct parport_ip32_private * const priv = p->physport->private_data;
	return parport_ip32_epp_write(priv->regs.eppData0, p, buf, len, flags);
}

/**
 * parport_ip32_epp_read_addr - read a block of addresses in EPP mode
 * @p:		pointer to &struct parport
 * @buf:	buffer to store read data
 * @len:	length of buffer @buf
 * @flags:	may be PARPORT_EPP_FAST
 */
static size_t parport_ip32_epp_read_addr(struct parport *p, void *buf,
					 size_t len, int flags)
{
	struct parport_ip32_private * const priv = p->physport->private_data;
	return parport_ip32_epp_read(priv->regs.eppAddr, p, buf, len, flags);
}

/**
 * parport_ip32_epp_write_addr - write a block of addresses in EPP mode
 * @p:		pointer to &struct parport
 * @buf:	buffer of data to write
 * @len:	length of buffer @buf
 * @flags:	may be PARPORT_EPP_FAST
 */
static size_t parport_ip32_epp_write_addr(struct parport *p, const void *buf,
					  size_t len, int flags)
{
	struct parport_ip32_private * const priv = p->physport->private_data;
	return parport_ip32_epp_write(priv->regs.eppAddr, p, buf, len, flags);
}

/*--- ECP mode functions (FIFO) ----------------------------------------*/

/**
 * parport_ip32_fifo_wait_break - check if the waiting function should return
 * @p:		pointer to &struct parport
 * @expire:	timeout expiring date, in jiffies
 *
 * parport_ip32_fifo_wait_break() checks if the waiting function should return
 * immediately or not.  The break conditions are:
 *	- expired timeout;
 *	- a pending signal;
 *	- nFault asserted low.
 * This function also calls cond_resched().
 */
static unsigned int parport_ip32_fifo_wait_break(struct parport *p,
						 unsigned long expire)
{
	cond_resched();
	if (time_after(jiffies, expire)) {
		pr_debug1(PPIP32 "%s: FIFO write timed out\n", p->name);
		return 1;
	}
	if (signal_pending(current)) {
		pr_debug1(PPIP32 "%s: Signal pending\n", p->name);
		return 1;
	}
	if (!(parport_ip32_read_status(p) & DSR_nFAULT)) {
		pr_debug1(PPIP32 "%s: nFault asserted low\n", p->name);
		return 1;
	}
	return 0;
}

/**
 * parport_ip32_fwp_wait_polling - wait for FIFO to empty (polling)
 * @p:		pointer to &struct parport
 *
 * Returns the number of bytes that can safely be written in the FIFO.  A
 * return value of zero means that the calling function should terminate as
 * fast as possible.
 */
static unsigned int parport_ip32_fwp_wait_polling(struct parport *p)
{
	struct parport_ip32_private * const priv = p->physport->private_data;
	struct parport * const physport = p->physport;
	unsigned long expire;
	unsigned int count;
	unsigned int ecr;