spi: move bitbang txrx utility functions to private header

A number of files in drivers/spi fail checkincludes.pl due to the double
include of <linux/spi/spi_bitbang.h>.

The first include is needed to get the struct spi_bitbang definition and
the spi_bitbang_* function prototypes.

The second include happens after defining EXPAND_BITBANG_TXRX to get the
inlined bitbang_txrx_* utility functions.

The <linux/spi/spi_bitbang.h> header is also included by a number of other
spi drivers, as well as some arch/ code, in order to use struct spi_bitbang
and the associated functions.

To fix the double include, and remove any potential confusion about it, move
the inlined bitbang_txrx_* functions to a new private header in drivers/spi
and also remove the need to define EXPAND_BITBANG_TXRX.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 0 insertions, 101 deletions

diff --git a/include/linux/spi/spi_bitbang.h b/include/linux/spi/spi_bitbang.h
index 3274c507b8a9..f987a2bee16a 100644
--- a/include/linux/spi/spi_bitbang.h
+++ b/include/linux/spi/spi_bitbang.h
@@ -1,24 +1,6 @@
 #ifndef __SPI_BITBANG_H
 #define __SPI_BITBANG_H
 
-/*
- * Mix this utility code with some glue code to get one of several types of
- * simple SPI master driver.  Two do polled word-at-a-time I/O:
- *
- *   -  GPIO/parport bitbangers.  Provide chipselect() and txrx_word[](),
- *      expanding the per-word routines from the inline templates below.
- *
- *   -  Drivers for controllers resembling bare shift registers.  Provide
- *      chipselect() and txrx_word[](), with custom setup()/cleanup() methods
- *      that use your controller's clock and chipselect registers.
- *
- * Some hardware works well with requests at spi_transfer scope:
- *
- *   -  Drivers leveraging smarter hardware, with fifos or DMA; or for half
- *      duplex (MicroWire) controllers.  Provide chipselect() and txrx_bufs(),
- *      and custom setup()/cleanup() methods.
- */
-
 #include <linux/workqueue.h>
 
 struct spi_bitbang {
@@ -68,86 +50,3 @@ extern int spi_bitbang_start(struct spi_bitbang *spi);
 extern int spi_bitbang_stop(struct spi_bitbang *spi);
 
 #endif  /* __SPI_BITBANG_H */
-
-/*-------------------------------------------------------------------------*/
-
-#ifdef  EXPAND_BITBANG_TXRX
-
-/*
- * The code that knows what GPIO pins do what should have declared four
- * functions, ideally as inlines, before #defining EXPAND_BITBANG_TXRX
- * and including this header:
- *
- *  void setsck(struct spi_device *, int is_on);
- *  void setmosi(struct spi_device *, int is_on);
- *  int getmiso(struct spi_device *);
- *  void spidelay(unsigned);
- *
- * setsck()'s is_on parameter is a zero/nonzero boolean.
- *
- * setmosi()'s is_on parameter is a zero/nonzero boolean.
- *
- * getmiso() is required to return 0 or 1 only. Any other value is invalid
- * and will result in improper operation.
- *
- * A non-inlined routine would call bitbang_txrx_*() routines.  The
- * main loop could easily compile down to a handful of instructions,
- * especially if the delay is a NOP (to run at peak speed).
- *
- * Since this is software, the timings may not be exactly what your board's
- * chips need ... there may be several reasons you'd need to tweak timings
- * in these routines, not just make to make it faster or slower to match a
- * particular CPU clock rate.
- */
-
-static inline u32
-bitbang_txrx_be_cpha0(struct spi_device *spi,
-                unsigned nsecs, unsigned cpol,
-                u32 word, u8 bits)
-{
-        /* if (cpol == 0) this is SPI_MODE_0; else this is SPI_MODE_2 */
-
-        /* clock starts at inactive polarity */
-        for (word <<= (32 - bits); likely(bits); bits--) {
-
-                /* setup MSB (to slave) on trailing edge */
-                setmosi(spi, word & (1 << 31));
-                spidelay(nsecs);        /* T(setup) */
-
-                setsck(spi, !cpol);
-                spidelay(nsecs);
-
-                /* sample MSB (from slave) on leading edge */
-                word <<= 1;
-                word |= getmiso(spi);
-                setsck(spi, cpol);
-        }
-        return word;
-}
-
-static inline u32
-bitbang_txrx_be_cpha1(struct spi_device *spi,
-                unsigned nsecs, unsigned cpol,
-                u32 word, u8 bits)
-{
-        /* if (cpol == 0) this is SPI_MODE_1; else this is SPI_MODE_3 */
-
-        /* clock starts at inactive polarity */
-        for (word <<= (32 - bits); likely(bits); bits--) {
-
-                /* setup MSB (to slave) on leading edge */
-                setsck(spi, !cpol);
-                setmosi(spi, word & (1 << 31));
-                spidelay(nsecs); /* T(setup) */
-
-                setsck(spi, cpol);
-                spidelay(nsecs);
-
-                /* sample MSB (from slave) on trailing edge */
-                word <<= 1;
-                word |= getmiso(spi);
-        }
-        return word;
-}
-
-#endif  /* EXPAND_BITBANG_TXRX */