Merge tag 'staging-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging driver tree merge from Greg Kroah-Hartman:
 "Here's the big staging tree merge for 3.8-rc1

  There's a lot of patches in here, the majority being the comedi
  rework/cleanup that has been ongoing and is causing a huge reduction
  in overall code size, which is amazing to watch.  We also removed some
  older drivers (telephony and rts_pstor), and added a new one (fwserial
  which also came in through the tty tree due to tty api changes, take
  that one if you get merge conflicts.)

  The iio and ipack drivers are moving out of the staging area into
  their own part of the kernel as they have been cleaned up sufficiently
  and are working well.

  Overall, again a reduction of code:
   768 files changed, 31887 insertions(+), 82166 deletions(-)

  All of this has been in the linux-next tree for a while.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'staging-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1298 commits)
  iio: imu: adis16480: remove duplicated include from adis16480.c
  iio: gyro: adis16136: remove duplicated include from adis16136.c
  iio:imu: adis16480: show_firmware() buffer too small
  iio:gyro: adis16136: divide by zero in write_frequency()
  iio: adc: Add Texas Instruments ADC081C021/027 support
  iio:ad7793: Add support for the ad7796 and ad7797
  iio:ad7793: Add support for the ad7798 and ad7799
  staging:iio: Move ad7793 driver out of staging
  staging:iio:ad7793: Implement stricter id checking
  staging:iio:ad7793: Move register definitions from header to source
  staging:iio:ad7793: Rework regulator handling
  staging:iio:ad7793: Rework platform data
  staging:iio:ad7793: Use kstrtol instead of strict_strtol
  staging:iio:ad7793: Use usleep_range instead of msleep
  staging:iio:ad7793: Fix temperature scale
  staging:iio:ad7793: Fix VDD monitor scale
  staging: gdm72xx: unlock on error in init_usb()
  staging: panel: pass correct lengths to keypad_send_key()
  staging: comedi: addi_apci_2032: fix interrupt support
  staging: comedi: addi_apci_2032: move i_APCI2032_ConfigDigitalOutput()
  ...

1 files changed, 130 insertions, 0 deletions

diff --git a/drivers/staging/fwserial/dma_fifo.h b/drivers/staging/fwserial/dma_fifo.h
new file mode 100644
index 000000000000..a113fe1e6f19
--- /dev/null
+++ b/drivers/staging/fwserial/dma_fifo.h
@@ -0,0 +1,130 @@
+/*
+ * DMA-able FIFO interface
+ *
+ * Copyright (C) 2012 Peter Hurley <peter@hurleysoftware.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef _DMA_FIFO_H_
+#define _DMA_FIFO_H_
+
+/**
+ * The design basis for the DMA FIFO is to provide an output side that
+ * complies with the streaming DMA API design that can be DMA'd from directly
+ * (without additional copying), coupled with an input side that maintains a
+ * logically consistent 'apparent' size (ie, bytes in + bytes avail is static
+ * for the lifetime of the FIFO).
+ *
+ * DMA output transactions originate on a cache line boundary and can be
+ * variably-sized. DMA output transactions can be retired out-of-order but
+ * the FIFO will only advance the output in the original input sequence.
+ * This means the FIFO will eventually stall if a transaction is never retired.
+ *
+ * Chunking the output side into cache line multiples means that some FIFO
+ * memory is unused. For example, if all the avail input has been pended out,
+ * then the in and out markers are re-aligned to the next cache line.
+ * The maximum possible waste is
+ *     (cache line alignment - 1) * (max outstanding dma transactions)
+ * This potential waste requires additional hidden capacity within the FIFO
+ * to be able to accept input while the 'apparent' size has not been reached.
+ *
+ * Additional cache lines (ie, guard area) are used to minimize DMA
+ * fragmentation when wrapping at the end of the FIFO. Input is allowed into the
+ * guard area, but the in and out FIFO markers are wrapped when DMA is pended.
+ */
+
+#define DMA_FIFO_GUARD 3   /* # of cache lines to reserve for the guard area */
+
+struct dma_fifo {
+	unsigned	 in;
+	unsigned	 out;		/* updated when dma is pended         */
+	unsigned	 done;		/* updated upon dma completion        */
+	struct {
+		unsigned corrupt:1;
+	};
+	int		 size;		/* 'apparent' size of fifo	      */
+	int		 guard;		/* ofs of guard area		      */
+	int		 capacity;	/* size + reserved                    */
+	int		 avail;		/* # of unused bytes in fifo          */
+	unsigned	 align;		/* must be power of 2                 */
+	int		 tx_limit;	/* max # of bytes per dma transaction */
+	int		 open_limit;	/* max # of outstanding allowed       */
+	int		 open;		/* # of outstanding dma transactions  */
+	struct list_head pending;	/* fifo markers for outstanding dma   */
+	void		 *data;
+};
+
+struct dma_pending {
+	struct list_head link;
+	void		 *data;
+	unsigned	 len;
+	unsigned         next;
+	unsigned         out;
+};
+
+static inline void dp_mark_completed(struct dma_pending *dp)
+{
+	dp->data += 1;
+}
+
+static inline bool dp_is_completed(struct dma_pending *dp)
+{
+	return (unsigned long)dp->data & 1UL;
+}
+
+extern void dma_fifo_init(struct dma_fifo *fifo);
+extern int dma_fifo_alloc(struct dma_fifo *fifo, int size, unsigned align,
+			  int tx_limit, int open_limit, gfp_t gfp_mask);
+extern void dma_fifo_free(struct dma_fifo *fifo);
+extern void dma_fifo_reset(struct dma_fifo *fifo);
+extern int dma_fifo_in(struct dma_fifo *fifo, const void *src, int n);
+extern int dma_fifo_out_pend(struct dma_fifo *fifo, struct dma_pending *pended);
+extern int dma_fifo_out_complete(struct dma_fifo *fifo,
+				 struct dma_pending *complete);
+
+/* returns the # of used bytes in the fifo */
+static inline int dma_fifo_level(struct dma_fifo *fifo)
+{
+	return fifo->size - fifo->avail;
+}
+
+/* returns the # of bytes ready for output in the fifo */
+static inline int dma_fifo_out_level(struct dma_fifo *fifo)
+{
+	return fifo->in - fifo->out;
+}
+
+/* returns the # of unused bytes in the fifo */
+static inline int dma_fifo_avail(struct dma_fifo *fifo)
+{
+	return fifo->avail;
+}
+
+/* returns true if fifo has max # of outstanding dmas */
+static inline bool dma_fifo_busy(struct dma_fifo *fifo)
+{
+	return fifo->open == fifo->open_limit;
+}
+
+/* changes the max size of dma returned from dma_fifo_out_pend() */
+static inline int dma_fifo_change_tx_limit(struct dma_fifo *fifo, int tx_limit)
+{
+	tx_limit = round_down(tx_limit, fifo->align);
+	fifo->tx_limit = max_t(int, tx_limit, fifo->align);
+	return 0;
+}
+
+#endif /* _DMA_FIFO_H_ */