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spi: spi-pxa2xx: remove legacy PXA DMA bits

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Generic DMA support was already implemented by commit cd7bed0034
("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@gmail.com>
Acked-by: Mark Brown <broonie@linaro.org>
[respin after pxa dmaengine support upstream]
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Daniel Mack 2015-06-08 22:32:37 +02:00 committed by Mark Brown
parent 82ba2c2ab3
commit 6356437e65
4 changed files with 2 additions and 501 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

9
drivers/spi/Kconfig
View file

@ -393,16 +393,9 @@ 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"

1
drivers/spi/Makefile
View file

@ -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

487
drivers/spi/spi-pxa2xx-pxadma.c
View file

@ -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;
}

6
drivers/spi/spi-pxa2xx.h
View file

@ -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)