spi: reorganize drivers

Sort the SPI makefile and enforce the naming convention spi_*.c for
spi drivers.

This change also rolls the contents of atmel_spi.h into the .c file
since there is only one user of that particular include file.

v2: - Use 'spi-' prefix instead of 'spi_' to match what seems to be
      be the predominant pattern for subsystem prefixes.
    - Clean up filenames in Kconfig and header comment blocks

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 0 insertions, 505 deletions

diff --git a/drivers/spi/spi_bitbang.c b/drivers/spi/spi_bitbang.c
deleted file mode 100644
index bb38c83ba210..000000000000
--- a/drivers/spi/spi_bitbang.c
+++ /dev/null
@@ -1,505 +0,0 @@
-/*
- * spi_bitbang.c - polling/bitbanging SPI master controller driver utilities
- *
- * 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
- */
-
-#include <linux/init.h>
-#include <linux/spinlock.h>
-#include <linux/workqueue.h>
-#include <linux/interrupt.h>
-#include <linux/delay.h>
-#include <linux/errno.h>
-#include <linux/platform_device.h>
-#include <linux/slab.h>
-
-#include <linux/spi/spi.h>
-#include <linux/spi/spi_bitbang.h>
-
-
-/*----------------------------------------------------------------------*/
-
-/*
- * FIRST PART (OPTIONAL):  word-at-a-time spi_transfer support.
- * Use this for GPIO or shift-register level hardware APIs.
- *
- * spi_bitbang_cs is in spi_device->controller_state, which is unavailable
- * to glue code.  These bitbang setup() and cleanup() routines are always
- * used, though maybe they're called from controller-aware code.
- *
- * chipselect() and friends may use use spi_device->controller_data and
- * controller registers as appropriate.
- *
- *
- * NOTE:  SPI controller pins can often be used as GPIO pins instead,
- * which means you could use a bitbang driver either to get hardware
- * working quickly, or testing for differences that aren't speed related.
- */
-
-struct spi_bitbang_cs {
-	unsigned	nsecs;	/* (clock cycle time)/2 */
-	u32		(*txrx_word)(struct spi_device *spi, unsigned nsecs,
-					u32 word, u8 bits);
-	unsigned	(*txrx_bufs)(struct spi_device *,
-					u32 (*txrx_word)(
-						struct spi_device *spi,
-						unsigned nsecs,
-						u32 word, u8 bits),
-					unsigned, struct spi_transfer *);
-};
-
-static unsigned bitbang_txrx_8(
-	struct spi_device	*spi,
-	u32			(*txrx_word)(struct spi_device *spi,
-					unsigned nsecs,
-					u32 word, u8 bits),
-	unsigned		ns,
-	struct spi_transfer	*t
-) {
-	unsigned		bits = t->bits_per_word ? : spi->bits_per_word;
-	unsigned		count = t->len;
-	const u8		*tx = t->tx_buf;
-	u8			*rx = t->rx_buf;
-
-	while (likely(count > 0)) {
-		u8		word = 0;
-
-		if (tx)
-			word = *tx++;
-		word = txrx_word(spi, ns, word, bits);
-		if (rx)
-			*rx++ = word;
-		count -= 1;
-	}
-	return t->len - count;
-}
-
-static unsigned bitbang_txrx_16(
-	struct spi_device	*spi,
-	u32			(*txrx_word)(struct spi_device *spi,
-					unsigned nsecs,
-					u32 word, u8 bits),
-	unsigned		ns,
-	struct spi_transfer	*t
-) {
-	unsigned		bits = t->bits_per_word ? : spi->bits_per_word;
-	unsigned		count = t->len;
-	const u16		*tx = t->tx_buf;
-	u16			*rx = t->rx_buf;
-
-	while (likely(count > 1)) {
-		u16		word = 0;
-
-		if (tx)
-			word = *tx++;
-		word = txrx_word(spi, ns, word, bits);
-		if (rx)
-			*rx++ = word;
-		count -= 2;
-	}
-	return t->len - count;
-}
-
-static unsigned bitbang_txrx_32(
-	struct spi_device	*spi,
-	u32			(*txrx_word)(struct spi_device *spi,
-					unsigned nsecs,
-					u32 word, u8 bits),
-	unsigned		ns,
-	struct spi_transfer	*t
-) {
-	unsigned		bits = t->bits_per_word ? : spi->bits_per_word;
-	unsigned		count = t->len;
-	const u32		*tx = t->tx_buf;
-	u32			*rx = t->rx_buf;
-
-	while (likely(count > 3)) {
-		u32		word = 0;
-
-		if (tx)
-			word = *tx++;
-		word = txrx_word(spi, ns, word, bits);
-		if (rx)
-			*rx++ = word;
-		count -= 4;
-	}
-	return t->len - count;
-}
-
-int spi_bitbang_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
-{
-	struct spi_bitbang_cs	*cs = spi->controller_state;
-	u8			bits_per_word;
-	u32			hz;
-
-	if (t) {
-		bits_per_word = t->bits_per_word;
-		hz = t->speed_hz;
-	} else {
-		bits_per_word = 0;
-		hz = 0;
-	}
-
-	/* spi_transfer level calls that work per-word */
-	if (!bits_per_word)
-		bits_per_word = spi->bits_per_word;
-	if (bits_per_word <= 8)
-		cs->txrx_bufs = bitbang_txrx_8;
-	else if (bits_per_word <= 16)
-		cs->txrx_bufs = bitbang_txrx_16;
-	else if (bits_per_word <= 32)
-		cs->txrx_bufs = bitbang_txrx_32;
-	else
-		return -EINVAL;
-
-	/* nsecs = (clock period)/2 */
-	if (!hz)
-		hz = spi->max_speed_hz;
-	if (hz) {
-		cs->nsecs = (1000000000/2) / hz;
-		if (cs->nsecs > (MAX_UDELAY_MS * 1000 * 1000))
-			return -EINVAL;
-	}
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(spi_bitbang_setup_transfer);
-
-/**
- * spi_bitbang_setup - default setup for per-word I/O loops
- */
-int spi_bitbang_setup(struct spi_device *spi)
-{
-	struct spi_bitbang_cs	*cs = spi->controller_state;
-	struct spi_bitbang	*bitbang;
-	int			retval;
-	unsigned long		flags;
-
-	bitbang = spi_master_get_devdata(spi->master);
-
-	if (!cs) {
-		cs = kzalloc(sizeof *cs, GFP_KERNEL);
-		if (!cs)
-			return -ENOMEM;
-		spi->controller_state = cs;
-	}
-
-	/* per-word shift register access, in hardware or bitbanging */
-	cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)];
-	if (!cs->txrx_word)
-		return -EINVAL;
-
-	retval = bitbang->setup_transfer(spi, NULL);
-	if (retval < 0)
-		return retval;
-
-	dev_dbg(&spi->dev, "%s, %u nsec/bit\n", __func__, 2 * cs->nsecs);
-
-	/* NOTE we _need_ to call chipselect() early, ideally with adapter
-	 * setup, unless the hardware defaults cooperate to avoid confusion
-	 * between normal (active low) and inverted chipselects.
-	 */
-
-	/* deselect chip (low or high) */
-	spin_lock_irqsave(&bitbang->lock, flags);
-	if (!bitbang->busy) {
-		bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
-		ndelay(cs->nsecs);
-	}
-	spin_unlock_irqrestore(&bitbang->lock, flags);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(spi_bitbang_setup);
-
-/**
- * spi_bitbang_cleanup - default cleanup for per-word I/O loops
- */
-void spi_bitbang_cleanup(struct spi_device *spi)
-{
-	kfree(spi->controller_state);
-}
-EXPORT_SYMBOL_GPL(spi_bitbang_cleanup);
-
-static int spi_bitbang_bufs(struct spi_device *spi, struct spi_transfer *t)
-{
-	struct spi_bitbang_cs	*cs = spi->controller_state;
-	unsigned		nsecs = cs->nsecs;
-
-	return cs->txrx_bufs(spi, cs->txrx_word, nsecs, t);
-}
-
-/*----------------------------------------------------------------------*/
-
-/*
- * SECOND PART ... simple transfer queue runner.
- *
- * This costs a task context per controller, running the queue by
- * performing each transfer in sequence.  Smarter hardware can queue
- * several DMA transfers at once, and process several controller queues
- * in parallel; this driver doesn't match such hardware very well.
- *
- * Drivers can provide word-at-a-time i/o primitives, or provide
- * transfer-at-a-time ones to leverage dma or fifo hardware.
- */
-static void bitbang_work(struct work_struct *work)
-{
-	struct spi_bitbang	*bitbang =
-		container_of(work, struct spi_bitbang, work);
-	unsigned long		flags;
-
-	spin_lock_irqsave(&bitbang->lock, flags);
-	bitbang->busy = 1;
-	while (!list_empty(&bitbang->queue)) {
-		struct spi_message	*m;
-		struct spi_device	*spi;
-		unsigned		nsecs;
-		struct spi_transfer	*t = NULL;
-		unsigned		tmp;
-		unsigned		cs_change;
-		int			status;
-		int			do_setup = -1;
-
-		m = container_of(bitbang->queue.next, struct spi_message,
-				queue);
-		list_del_init(&m->queue);
-		spin_unlock_irqrestore(&bitbang->lock, flags);
-
-		/* FIXME this is made-up ... the correct value is known to
-		 * word-at-a-time bitbang code, and presumably chipselect()
-		 * should enforce these requirements too?
-		 */
-		nsecs = 100;
-
-		spi = m->spi;
-		tmp = 0;
-		cs_change = 1;
-		status = 0;
-
-		list_for_each_entry (t, &m->transfers, transfer_list) {
-
-			/* override speed or wordsize? */
-			if (t->speed_hz || t->bits_per_word)
-				do_setup = 1;
-
-			/* init (-1) or override (1) transfer params */
-			if (do_setup != 0) {
-				status = bitbang->setup_transfer(spi, t);
-				if (status < 0)
-					break;
-				if (do_setup == -1)
-					do_setup = 0;
-			}
-
-			/* set up default clock polarity, and activate chip;
-			 * this implicitly updates clock and spi modes as
-			 * previously recorded for this device via setup().
-			 * (and also deselects any other chip that might be
-			 * selected ...)
-			 */
-			if (cs_change) {
-				bitbang->chipselect(spi, BITBANG_CS_ACTIVE);
-				ndelay(nsecs);
-			}
-			cs_change = t->cs_change;
-			if (!t->tx_buf && !t->rx_buf && t->len) {
-				status = -EINVAL;
-				break;
-			}
-
-			/* transfer data.  the lower level code handles any
-			 * new dma mappings it needs. our caller always gave
-			 * us dma-safe buffers.
-			 */
-			if (t->len) {
-				/* REVISIT dma API still needs a designated
-				 * DMA_ADDR_INVALID; ~0 might be better.
-				 */
-				if (!m->is_dma_mapped)
-					t->rx_dma = t->tx_dma = 0;
-				status = bitbang->txrx_bufs(spi, t);
-			}
-			if (status > 0)
-				m->actual_length += status;
-			if (status != t->len) {
-				/* always report some kind of error */
-				if (status >= 0)
-					status = -EREMOTEIO;
-				break;
-			}
-			status = 0;
-
-			/* protocol tweaks before next transfer */
-			if (t->delay_usecs)
-				udelay(t->delay_usecs);
-
-			if (!cs_change)
-				continue;
-			if (t->transfer_list.next == &m->transfers)
-				break;
-
-			/* sometimes a short mid-message deselect of the chip
-			 * may be needed to terminate a mode or command
-			 */
-			ndelay(nsecs);
-			bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
-			ndelay(nsecs);
-		}
-
-		m->status = status;
-		m->complete(m->context);
-
-		/* normally deactivate chipselect ... unless no error and
-		 * cs_change has hinted that the next message will probably
-		 * be for this chip too.
-		 */
-		if (!(status == 0 && cs_change)) {
-			ndelay(nsecs);
-			bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
-			ndelay(nsecs);
-		}
-
-		spin_lock_irqsave(&bitbang->lock, flags);
-	}
-	bitbang->busy = 0;
-	spin_unlock_irqrestore(&bitbang->lock, flags);
-}
-
-/**
- * spi_bitbang_transfer - default submit to transfer queue
- */
-int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m)
-{
-	struct spi_bitbang	*bitbang;
-	unsigned long		flags;
-	int			status = 0;
-
-	m->actual_length = 0;
-	m->status = -EINPROGRESS;
-
-	bitbang = spi_master_get_devdata(spi->master);
-
-	spin_lock_irqsave(&bitbang->lock, flags);
-	if (!spi->max_speed_hz)
-		status = -ENETDOWN;
-	else {
-		list_add_tail(&m->queue, &bitbang->queue);
-		queue_work(bitbang->workqueue, &bitbang->work);
-	}
-	spin_unlock_irqrestore(&bitbang->lock, flags);
-
-	return status;
-}
-EXPORT_SYMBOL_GPL(spi_bitbang_transfer);
-
-/*----------------------------------------------------------------------*/
-
-/**
- * spi_bitbang_start - start up a polled/bitbanging SPI master driver
- * @bitbang: driver handle
- *
- * Caller should have zero-initialized all parts of the structure, and then
- * provided callbacks for chip selection and I/O loops.  If the master has
- * a transfer method, its final step should call spi_bitbang_transfer; or,
- * that's the default if the transfer routine is not initialized.  It should
- * also set up the bus number and number of chipselects.
- *
- * For i/o loops, provide callbacks either per-word (for bitbanging, or for
- * hardware that basically exposes a shift register) or per-spi_transfer
- * (which takes better advantage of hardware like fifos or DMA engines).
- *
- * Drivers using per-word I/O loops should use (or call) spi_bitbang_setup,
- * spi_bitbang_cleanup and spi_bitbang_setup_transfer to handle those spi
- * master methods.  Those methods are the defaults if the bitbang->txrx_bufs
- * routine isn't initialized.
- *
- * This routine registers the spi_master, which will process requests in a
- * dedicated task, keeping IRQs unblocked most of the time.  To stop
- * processing those requests, call spi_bitbang_stop().
- */
-int spi_bitbang_start(struct spi_bitbang *bitbang)
-{
-	int	status;
-
-	if (!bitbang->master || !bitbang->chipselect)
-		return -EINVAL;
-
-	INIT_WORK(&bitbang->work, bitbang_work);
-	spin_lock_init(&bitbang->lock);
-	INIT_LIST_HEAD(&bitbang->queue);
-
-	if (!bitbang->master->mode_bits)
-		bitbang->master->mode_bits = SPI_CPOL | SPI_CPHA | bitbang->flags;
-
-	if (!bitbang->master->transfer)
-		bitbang->master->transfer = spi_bitbang_transfer;
-	if (!bitbang->txrx_bufs) {
-		bitbang->use_dma = 0;
-		bitbang->txrx_bufs = spi_bitbang_bufs;
-		if (!bitbang->master->setup) {
-			if (!bitbang->setup_transfer)
-				bitbang->setup_transfer =
-					 spi_bitbang_setup_transfer;
-			bitbang->master->setup = spi_bitbang_setup;
-			bitbang->master->cleanup = spi_bitbang_cleanup;
-		}
-	} else if (!bitbang->master->setup)
-		return -EINVAL;
-	if (bitbang->master->transfer == spi_bitbang_transfer &&
-			!bitbang->setup_transfer)
-		return -EINVAL;
-
-	/* this task is the only thing to touch the SPI bits */
-	bitbang->busy = 0;
-	bitbang->workqueue = create_singlethread_workqueue(
-			dev_name(bitbang->master->dev.parent));
-	if (bitbang->workqueue == NULL) {
-		status = -EBUSY;
-		goto err1;
-	}
-
-	/* driver may get busy before register() returns, especially
-	 * if someone registered boardinfo for devices
-	 */
-	status = spi_register_master(bitbang->master);
-	if (status < 0)
-		goto err2;
-
-	return status;
-
-err2:
-	destroy_workqueue(bitbang->workqueue);
-err1:
-	return status;
-}
-EXPORT_SYMBOL_GPL(spi_bitbang_start);
-
-/**
- * spi_bitbang_stop - stops the task providing spi communication
- */
-int spi_bitbang_stop(struct spi_bitbang *bitbang)
-{
-	spi_unregister_master(bitbang->master);
-
-	WARN_ON(!list_empty(&bitbang->queue));
-
-	destroy_workqueue(bitbang->workqueue);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(spi_bitbang_stop);
-
-MODULE_LICENSE("GPL");
-