spi: spi-pxa2xx: remove legacy PXA DMA bits (6356437e) · Commits · 戴 / test

drivers/spi/Kconfig

+1 −8

Original line number	Diff line number	Diff line
		@@ -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"

drivers/spi/Makefile

+0 −1

Original line number	Diff line number	Diff line
		@@ -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

drivers/spi/spi-pxa2xx-pxadma.c

deleted100644 → 0

+0 −487

Original line number	Diff line number	Diff line
		/*
		* 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;
		}

drivers/spi/spi-pxa2xx.h

+1 −5

Original line number	Diff line number	Diff line
		@@ -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)

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