Message-Id: <1433795557-18036-1-git-send-email-robert.jarzmik@free.fr>
Date:	Mon,  8 Jun 2015 22:32:37 +0200
From:	Robert Jarzmik <robert.jarzmik@...e.fr>
To:	Mark Brown <broonie@...nel.org>, Daniel Mack <daniel@...que.org>,
	Haojian Zhuang <haojian.zhuang@...il.com>,
	Robert Jarzmik <robert.jarzmik@...e.fr>
Cc:	linux-kernel@...r.kernel.org, linux-spi@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	Daniel Mack <zonque@...il.com>,
	Mika Westerberg <mika.westerberg@...ux.intel.com>
Subject: [PATCH] spi: spi-pxa2xx: remove legacy PXA DMA bits

From: Daniel Mack <zonque@...il.com>

Generic DMA support was already implemented by commit cd7bed003404
("spi/pxa2xx: break out the private DMA API usage into a separate file")
which moved all the legacy PXA DMA implementation code into its own
file.

With generic DMA available for PXA, we can now just trash this file.

Signed-off-by: Daniel Mack <zonque@...il.com>
Cc: Mika Westerberg <mika.westerberg@...ux.intel.com>
Acked-by: Mark Brown <broonie@...aro.org>
[respin after pxa dmaengine support upstream]
Signed-off-by: Robert Jarzmik <robert.jarzmik@...e.fr>
---
 drivers/spi/Kconfig             |   9 +-
 drivers/spi/Makefile            |   1 -
 drivers/spi/spi-pxa2xx-pxadma.c | 487 ----------------------------------------
 drivers/spi/spi-pxa2xx.h        |   6 +-
 4 files changed, 2 insertions(+), 501 deletions(-)
 delete mode 100644 drivers/spi/spi-pxa2xx-pxadma.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 5bd7811..ec40a27 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -395,16 +395,9 @@ config SPI_PPC4xx
 	help
 	  This selects a driver for the PPC4xx SPI Controller.
 
-config SPI_PXA2XX_PXADMA
-	bool "PXA2xx SSP legacy PXA DMA API support"
-	depends on SPI_PXA2XX && ARCH_PXA
-	help
-	  Enable PXA private legacy DMA API support. Note that this is
-	  deprecated in favor of generic DMA engine API.
-
 config SPI_PXA2XX_DMA
 	def_bool y
-	depends on SPI_PXA2XX && !SPI_PXA2XX_PXADMA
+	depends on SPI_PXA2XX
 
 config SPI_PXA2XX
 	tristate "PXA2xx SSP SPI master"
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 0218f39..2e7089f 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -60,7 +60,6 @@ obj-$(CONFIG_SPI_ORION)			+= spi-orion.o
 obj-$(CONFIG_SPI_PL022)			+= spi-pl022.o
 obj-$(CONFIG_SPI_PPC4xx)		+= spi-ppc4xx.o
 spi-pxa2xx-platform-objs		:= spi-pxa2xx.o
-spi-pxa2xx-platform-$(CONFIG_SPI_PXA2XX_PXADMA)	+= spi-pxa2xx-pxadma.o
 spi-pxa2xx-platform-$(CONFIG_SPI_PXA2XX_DMA)	+= spi-pxa2xx-dma.o
 obj-$(CONFIG_SPI_PXA2XX)		+= spi-pxa2xx-platform.o
 obj-$(CONFIG_SPI_PXA2XX_PCI)		+= spi-pxa2xx-pci.o
diff --git a/drivers/spi/spi-pxa2xx-pxadma.c b/drivers/spi/spi-pxa2xx-pxadma.c
deleted file mode 100644
index 2e0796a..0000000
--- a/drivers/spi/spi-pxa2xx-pxadma.c
+++ /dev/null
@@ -1,487 +0,0 @@
-/*
- * PXA2xx SPI private DMA support.
- *
- * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
- *
- * 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.
- */
-
-#include <linux/delay.h>
-#include <linux/device.h>
-#include <linux/dma-mapping.h>
-#include <linux/pxa2xx_ssp.h>
-#include <linux/spi/spi.h>
-#include <linux/spi/pxa2xx_spi.h>
-
-#include <mach/dma.h>
-#include "spi-pxa2xx.h"
-
-#define DMA_INT_MASK		(DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR)
-#define RESET_DMA_CHANNEL	(DCSR_NODESC | DMA_INT_MASK)
-
-bool pxa2xx_spi_dma_is_possible(size_t len)
-{
-	/* Try to map dma buffer and do a dma transfer if successful, but
-	 * only if the length is non-zero and less than MAX_DMA_LEN.
-	 *
-	 * Zero-length non-descriptor DMA is illegal on PXA2xx; force use
-	 * of PIO instead.  Care is needed above because the transfer may
-	 * have have been passed with buffers that are already dma mapped.
-	 * A zero-length transfer in PIO mode will not try to write/read
-	 * to/from the buffers
-	 *
-	 * REVISIT large transfers are exactly where we most want to be
-	 * using DMA.  If this happens much, split those transfers into
-	 * multiple DMA segments rather than forcing PIO.
-	 */
-	return len > 0 && len <= MAX_DMA_LEN;
-}
-
-int pxa2xx_spi_map_dma_buffers(struct driver_data *drv_data)
-{
-	struct spi_message *msg = drv_data->cur_msg;
-	struct device *dev = &msg->spi->dev;
-
-	if (!drv_data->cur_chip->enable_dma)
-		return 0;
-
-	if (msg->is_dma_mapped)
-		return  drv_data->rx_dma && drv_data->tx_dma;
-
-	if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx))
-		return 0;
-
-	/* Modify setup if rx buffer is null */
-	if (drv_data->rx == NULL) {
-		*drv_data->null_dma_buf = 0;
-		drv_data->rx = drv_data->null_dma_buf;
-		drv_data->rx_map_len = 4;
-	} else
-		drv_data->rx_map_len = drv_data->len;
-
-
-	/* Modify setup if tx buffer is null */
-	if (drv_data->tx == NULL) {
-		*drv_data->null_dma_buf = 0;
-		drv_data->tx = drv_data->null_dma_buf;
-		drv_data->tx_map_len = 4;
-	} else
-		drv_data->tx_map_len = drv_data->len;
-
-	/* Stream map the tx buffer. Always do DMA_TO_DEVICE first
-	 * so we flush the cache *before* invalidating it, in case
-	 * the tx and rx buffers overlap.
-	 */
-	drv_data->tx_dma = dma_map_single(dev, drv_data->tx,
-					drv_data->tx_map_len, DMA_TO_DEVICE);
-	if (dma_mapping_error(dev, drv_data->tx_dma))
-		return 0;
-
-	/* Stream map the rx buffer */
-	drv_data->rx_dma = dma_map_single(dev, drv_data->rx,
-					drv_data->rx_map_len, DMA_FROM_DEVICE);
-	if (dma_mapping_error(dev, drv_data->rx_dma)) {
-		dma_unmap_single(dev, drv_data->tx_dma,
-					drv_data->tx_map_len, DMA_TO_DEVICE);
-		return 0;
-	}
-
-	return 1;
-}
-
-static void pxa2xx_spi_unmap_dma_buffers(struct driver_data *drv_data)
-{
-	struct device *dev;
-
-	if (!drv_data->dma_mapped)
-		return;
-
-	if (!drv_data->cur_msg->is_dma_mapped) {
-		dev = &drv_data->cur_msg->spi->dev;
-		dma_unmap_single(dev, drv_data->rx_dma,
-					drv_data->rx_map_len, DMA_FROM_DEVICE);
-		dma_unmap_single(dev, drv_data->tx_dma,
-					drv_data->tx_map_len, DMA_TO_DEVICE);
-	}
-
-	drv_data->dma_mapped = 0;
-}
-
-static int wait_ssp_rx_stall(struct driver_data *drv_data)
-{
-	unsigned long limit = loops_per_jiffy << 1;
-
-	while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_BSY) && --limit)
-		cpu_relax();
-
-	return limit;
-}
-
-static int wait_dma_channel_stop(int channel)
-{
-	unsigned long limit = loops_per_jiffy << 1;
-
-	while (!(DCSR(channel) & DCSR_STOPSTATE) && --limit)
-		cpu_relax();
-
-	return limit;
-}
-
-static void pxa2xx_spi_dma_error_stop(struct driver_data *drv_data,
-				      const char *msg)
-{
-	/* Stop and reset */
-	DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
-	DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
-	write_SSSR_CS(drv_data, drv_data->clear_sr);
-	pxa2xx_spi_write(drv_data, SSCR1,
-			 pxa2xx_spi_read(drv_data, SSCR1)
-			 & ~drv_data->dma_cr1);
-	if (!pxa25x_ssp_comp(drv_data))
-		pxa2xx_spi_write(drv_data, SSTO, 0);
-	pxa2xx_spi_flush(drv_data);
-	pxa2xx_spi_write(drv_data, SSCR0,
-			 pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE);
-
-	pxa2xx_spi_unmap_dma_buffers(drv_data);
-
-	dev_err(&drv_data->pdev->dev, "%s\n", msg);
-
-	drv_data->cur_msg->state = ERROR_STATE;
-	tasklet_schedule(&drv_data->pump_transfers);
-}
-
-static void pxa2xx_spi_dma_transfer_complete(struct driver_data *drv_data)
-{
-	struct spi_message *msg = drv_data->cur_msg;
-
-	/* Clear and disable interrupts on SSP and DMA channels*/
-	pxa2xx_spi_write(drv_data, SSCR1,
-			 pxa2xx_spi_read(drv_data, SSCR1)
-			 & ~drv_data->dma_cr1);
-	write_SSSR_CS(drv_data, drv_data->clear_sr);
-	DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
-	DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
-
-	if (wait_dma_channel_stop(drv_data->rx_channel) == 0)
-		dev_err(&drv_data->pdev->dev,
-			"dma_handler: dma rx channel stop failed\n");
-
-	if (wait_ssp_rx_stall(drv_data->ioaddr) == 0)
-		dev_err(&drv_data->pdev->dev,
-			"dma_transfer: ssp rx stall failed\n");
-
-	pxa2xx_spi_unmap_dma_buffers(drv_data);
-
-	/* update the buffer pointer for the amount completed in dma */
-	drv_data->rx += drv_data->len -
-			(DCMD(drv_data->rx_channel) & DCMD_LENGTH);
-
-	/* read trailing data from fifo, it does not matter how many
-	 * bytes are in the fifo just read until buffer is full
-	 * or fifo is empty, which ever occurs first */
-	drv_data->read(drv_data);
-
-	/* return count of what was actually read */
-	msg->actual_length += drv_data->len -
-				(drv_data->rx_end - drv_data->rx);
-
-	/* Transfer delays and chip select release are
-	 * handled in pump_transfers or giveback
-	 */
-
-	/* Move to next transfer */
-	msg->state = pxa2xx_spi_next_transfer(drv_data);
-
-	/* Schedule transfer tasklet */
-	tasklet_schedule(&drv_data->pump_transfers);
-}
-
-void pxa2xx_spi_dma_handler(int channel, void *data)
-{
-	struct driver_data *drv_data = data;
-	u32 irq_status = DCSR(channel) & DMA_INT_MASK;
-
-	if (irq_status & DCSR_BUSERR) {
-
-		if (channel == drv_data->tx_channel)
-			pxa2xx_spi_dma_error_stop(drv_data,
-				"dma_handler: bad bus address on tx channel");
-		else
-			pxa2xx_spi_dma_error_stop(drv_data,
-				"dma_handler: bad bus address on rx channel");
-		return;
-	}
-
-	/* PXA255x_SSP has no timeout interrupt, wait for tailing bytes */
-	if ((channel == drv_data->tx_channel)
-		&& (irq_status & DCSR_ENDINTR)
-		&& (drv_data->ssp_type == PXA25x_SSP)) {
-
-		/* Wait for rx to stall */
-		if (wait_ssp_rx_stall(drv_data) == 0)
-			dev_err(&drv_data->pdev->dev,
-				"dma_handler: ssp rx stall failed\n");
-
-		/* finish this transfer, start the next */
-		pxa2xx_spi_dma_transfer_complete(drv_data);
-	}
-}
-
-irqreturn_t pxa2xx_spi_dma_transfer(struct driver_data *drv_data)
-{
-	u32 irq_status;
-
-	irq_status = pxa2xx_spi_read(drv_data, SSSR) & drv_data->mask_sr;
-	if (irq_status & SSSR_ROR) {
-		pxa2xx_spi_dma_error_stop(drv_data,
-					  "dma_transfer: fifo overrun");
-		return IRQ_HANDLED;
-	}
-
-	/* Check for false positive timeout */
-	if ((irq_status & SSSR_TINT)
-		&& (DCSR(drv_data->tx_channel) & DCSR_RUN)) {
-		pxa2xx_spi_write(drv_data, SSSR, SSSR_TINT);
-		return IRQ_HANDLED;
-	}
-
-	if (irq_status & SSSR_TINT || drv_data->rx == drv_data->rx_end) {
-
-		/* Clear and disable timeout interrupt, do the rest in
-		 * dma_transfer_complete */
-		if (!pxa25x_ssp_comp(drv_data))
-			pxa2xx_spi_write(drv_data, SSTO, 0);
-
-		/* finish this transfer, start the next */
-		pxa2xx_spi_dma_transfer_complete(drv_data);
-
-		return IRQ_HANDLED;
-	}
-
-	/* Opps problem detected */
-	return IRQ_NONE;
-}
-
-int pxa2xx_spi_dma_prepare(struct driver_data *drv_data, u32 dma_burst)
-{
-	u32 dma_width;
-
-	switch (drv_data->n_bytes) {
-	case 1:
-		dma_width = DCMD_WIDTH1;
-		break;
-	case 2:
-		dma_width = DCMD_WIDTH2;
-		break;
-	default:
-		dma_width = DCMD_WIDTH4;
-		break;
-	}
-
-	/* Setup rx DMA Channel */
-	DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
-	DSADR(drv_data->rx_channel) = drv_data->ssdr_physical;
-	DTADR(drv_data->rx_channel) = drv_data->rx_dma;
-	if (drv_data->rx == drv_data->null_dma_buf)
-		/* No target address increment */
-		DCMD(drv_data->rx_channel) = DCMD_FLOWSRC
-						| dma_width
-						| dma_burst
-						| drv_data->len;
-	else
-		DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR
-						| DCMD_FLOWSRC
-						| dma_width
-						| dma_burst
-						| drv_data->len;
-
-	/* Setup tx DMA Channel */
-	DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
-	DSADR(drv_data->tx_channel) = drv_data->tx_dma;
-	DTADR(drv_data->tx_channel) = drv_data->ssdr_physical;
-	if (drv_data->tx == drv_data->null_dma_buf)
-		/* No source address increment */
-		DCMD(drv_data->tx_channel) = DCMD_FLOWTRG
-						| dma_width
-						| dma_burst
-						| drv_data->len;
-	else
-		DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR
-						| DCMD_FLOWTRG
-						| dma_width
-						| dma_burst
-						| drv_data->len;
-
-	/* Enable dma end irqs on SSP to detect end of transfer */
-	if (drv_data->ssp_type == PXA25x_SSP)
-		DCMD(drv_data->tx_channel) |= DCMD_ENDIRQEN;
-
-	return 0;
-}
-
-void pxa2xx_spi_dma_start(struct driver_data *drv_data)
-{
-	DCSR(drv_data->rx_channel) |= DCSR_RUN;
-	DCSR(drv_data->tx_channel) |= DCSR_RUN;
-}
-
-int pxa2xx_spi_dma_setup(struct driver_data *drv_data)
-{
-	struct device *dev = &drv_data->pdev->dev;
-	struct ssp_device *ssp = drv_data->ssp;
-
-	/* Get two DMA channels	(rx and tx) */
-	drv_data->rx_channel = pxa_request_dma("pxa2xx_spi_ssp_rx",
-						DMA_PRIO_HIGH,
-						pxa2xx_spi_dma_handler,
-						drv_data);
-	if (drv_data->rx_channel < 0) {
-		dev_err(dev, "problem (%d) requesting rx channel\n",
-			drv_data->rx_channel);
-		return -ENODEV;
-	}
-	drv_data->tx_channel = pxa_request_dma("pxa2xx_spi_ssp_tx",
-						DMA_PRIO_MEDIUM,
-						pxa2xx_spi_dma_handler,
-						drv_data);
-	if (drv_data->tx_channel < 0) {
-		dev_err(dev, "problem (%d) requesting tx channel\n",
-			drv_data->tx_channel);
-		pxa_free_dma(drv_data->rx_channel);
-		return -ENODEV;
-	}
-
-	DRCMR(ssp->drcmr_rx) = DRCMR_MAPVLD | drv_data->rx_channel;
-	DRCMR(ssp->drcmr_tx) = DRCMR_MAPVLD | drv_data->tx_channel;
-
-	return 0;
-}
-
-void pxa2xx_spi_dma_release(struct driver_data *drv_data)
-{
-	struct ssp_device *ssp = drv_data->ssp;
-
-	DRCMR(ssp->drcmr_rx) = 0;
-	DRCMR(ssp->drcmr_tx) = 0;
-
-	if (drv_data->tx_channel != 0)
-		pxa_free_dma(drv_data->tx_channel);
-	if (drv_data->rx_channel != 0)
-		pxa_free_dma(drv_data->rx_channel);
-}
-
-void pxa2xx_spi_dma_resume(struct driver_data *drv_data)
-{
-	if (drv_data->rx_channel != -1)
-		DRCMR(drv_data->ssp->drcmr_rx) =
-			DRCMR_MAPVLD | drv_data->rx_channel;
-	if (drv_data->tx_channel != -1)
-		DRCMR(drv_data->ssp->drcmr_tx) =
-			DRCMR_MAPVLD | drv_data->tx_channel;
-}
-
-int pxa2xx_spi_set_dma_burst_and_threshold(struct chip_data *chip,
-					   struct spi_device *spi,
-					   u8 bits_per_word, u32 *burst_code,
-					   u32 *threshold)
-{
-	struct pxa2xx_spi_chip *chip_info =
-			(struct pxa2xx_spi_chip *)spi->controller_data;
-	int bytes_per_word;
-	int burst_bytes;
-	int thresh_words;
-	int req_burst_size;
-	int retval = 0;
-
-	/* Set the threshold (in registers) to equal the same amount of data
-	 * as represented by burst size (in bytes).  The computation below
-	 * is (burst_size rounded up to nearest 8 byte, word or long word)
-	 * divided by (bytes/register); the tx threshold is the inverse of
-	 * the rx, so that there will always be enough data in the rx fifo
-	 * to satisfy a burst, and there will always be enough space in the
-	 * tx fifo to accept a burst (a tx burst will overwrite the fifo if
-	 * there is not enough space), there must always remain enough empty
-	 * space in the rx fifo for any data loaded to the tx fifo.
-	 * Whenever burst_size (in bytes) equals bits/word, the fifo threshold
-	 * will be 8, or half the fifo;
-	 * The threshold can only be set to 2, 4 or 8, but not 16, because
-	 * to burst 16 to the tx fifo, the fifo would have to be empty;
-	 * however, the minimum fifo trigger level is 1, and the tx will
-	 * request service when the fifo is at this level, with only 15 spaces.
-	 */
-
-	/* find bytes/word */
-	if (bits_per_word <= 8)
-		bytes_per_word = 1;
-	else if (bits_per_word <= 16)
-		bytes_per_word = 2;
-	else
-		bytes_per_word = 4;
-
-	/* use struct pxa2xx_spi_chip->dma_burst_size if available */
-	if (chip_info)
-		req_burst_size = chip_info->dma_burst_size;
-	else {
-		switch (chip->dma_burst_size) {
-		default:
-			/* if the default burst size is not set,
-			 * do it now */
-			chip->dma_burst_size = DCMD_BURST8;
-		case DCMD_BURST8:
-			req_burst_size = 8;
-			break;
-		case DCMD_BURST16:
-			req_burst_size = 16;
-			break;
-		case DCMD_BURST32:
-			req_burst_size = 32;
-			break;
-		}
-	}
-	if (req_burst_size <= 8) {
-		*burst_code = DCMD_BURST8;
-		burst_bytes = 8;
-	} else if (req_burst_size <= 16) {
-		if (bytes_per_word == 1) {
-			/* don't burst more than 1/2 the fifo */
-			*burst_code = DCMD_BURST8;
-			burst_bytes = 8;
-			retval = 1;
-		} else {
-			*burst_code = DCMD_BURST16;
-			burst_bytes = 16;
-		}
-	} else {
-		if (bytes_per_word == 1) {
-			/* don't burst more than 1/2 the fifo */
-			*burst_code = DCMD_BURST8;
-			burst_bytes = 8;
-			retval = 1;
-		} else if (bytes_per_word == 2) {
-			/* don't burst more than 1/2 the fifo */
-			*burst_code = DCMD_BURST16;
-			burst_bytes = 16;
-			retval = 1;
-		} else {
-			*burst_code = DCMD_BURST32;
-			burst_bytes = 32;
-		}
-	}
-
-	thresh_words = burst_bytes / bytes_per_word;
-
-	/* thresh_words will be between 2 and 8 */
-	*threshold = (SSCR1_RxTresh(thresh_words) & SSCR1_RFT)
-			| (SSCR1_TxTresh(16-thresh_words) & SSCR1_TFT);
-
-	return retval;
-}
diff --git a/drivers/spi/spi-pxa2xx.h b/drivers/spi/spi-pxa2xx.h
index 85a58c9..9f01e9c 100644
--- a/drivers/spi/spi-pxa2xx.h
+++ b/drivers/spi/spi-pxa2xx.h
@@ -162,11 +162,7 @@ extern void *pxa2xx_spi_next_transfer(struct driver_data *drv_data);
 /*
  * Select the right DMA implementation.
  */
-#if defined(CONFIG_SPI_PXA2XX_PXADMA)
-#define SPI_PXA2XX_USE_DMA	1
-#define MAX_DMA_LEN		8191
-#define DEFAULT_DMA_CR1		(SSCR1_TSRE | SSCR1_RSRE | SSCR1_TINTE)
-#elif defined(CONFIG_SPI_PXA2XX_DMA)
+#if defined(CONFIG_SPI_PXA2XX_DMA)
 #define SPI_PXA2XX_USE_DMA	1
 #define MAX_DMA_LEN		SZ_64K
 #define DEFAULT_DMA_CR1		(SSCR1_TSRE | SSCR1_RSRE | SSCR1_TRAIL)
-- 
2.1.4

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