Commit e79e7c2d authored by Nikita Shubin's avatar Nikita Shubin Committed by Arnd Bergmann
Browse files

spi: ep93xx: add DT support for Cirrus EP93xx 



- add OF ID match table
- add device tree DMA request, so we can probe defer, in case DMA is not
  ready yet
- drop DMA platform code

Signed-off-by: default avatarNikita Shubin <nikita.shubin@maquefel.me>
Tested-by: default avatarAlexander Sverdlin <alexander.sverdlin@gmail.com>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: default avatarMark Brown <broonie@kernel.org>
Acked-by: default avatarAlexander Sverdlin <alexander.sverdlin@gmail.com>
Acked-by: default avatarVinod Koul <vkoul@kernel.org>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent cb029177

drivers/spi/spi-ep93xx.c

+23 −43
Original line number Diff line number Diff line
@@ -18,18 +18,18 @@ 
#include <linux/err.h>

#include <linux/delay.h>

#include <linux/device.h>

#include <linux/dma-direction.h>

#include <linux/dma-mapping.h>

#include <linux/dmaengine.h>

#include <linux/bitops.h>

#include <linux/interrupt.h>

#include <linux/module.h>

#include <linux/property.h>

#include <linux/platform_device.h>

#include <linux/sched.h>

#include <linux/scatterlist.h>

#include <linux/spi/spi.h>



#include <linux/platform_data/dma-ep93xx.h>

#include <linux/platform_data/spi-ep93xx.h>



#define SSPCR0			0x0000

#define SSPCR0_SPO		BIT(6)

#define SSPCR0_SPH		BIT(7)
@@ -92,8 +92,6 @@ struct ep93xx_spi { 
	size_t				fifo_level;

	struct dma_chan			*dma_rx;

	struct dma_chan			*dma_tx;

	struct ep93xx_dma_data		dma_rx_data;

	struct ep93xx_dma_data		dma_tx_data;

	struct sg_table			rx_sgt;

	struct sg_table			tx_sgt;

	void				*zeropage;
@@ -575,46 +573,23 @@ static int ep93xx_spi_unprepare_hardware(struct spi_controller *host) 
	return 0;

}



static bool ep93xx_spi_dma_filter(struct dma_chan *chan, void *filter_param)

{

	if (ep93xx_dma_chan_is_m2p(chan))

		return false;



	chan->private = filter_param;

	return true;

}



static int ep93xx_spi_setup_dma(struct ep93xx_spi *espi)

static int ep93xx_spi_setup_dma(struct device *dev, struct ep93xx_spi *espi)

{

	dma_cap_mask_t mask;

	int ret;



	espi->zeropage = (void *)get_zeroed_page(GFP_KERNEL);

	if (!espi->zeropage)

		return -ENOMEM;



	dma_cap_zero(mask);

	dma_cap_set(DMA_SLAVE, mask);



	espi->dma_rx_data.port = EP93XX_DMA_SSP;

	espi->dma_rx_data.direction = DMA_DEV_TO_MEM;

	espi->dma_rx_data.name = "ep93xx-spi-rx";



	espi->dma_rx = dma_request_channel(mask, ep93xx_spi_dma_filter,

					   &espi->dma_rx_data);

	if (!espi->dma_rx) {

		ret = -ENODEV;

	espi->dma_rx = dma_request_chan(dev, "rx");

	if (IS_ERR(espi->dma_rx)) {

		ret = dev_err_probe(dev, PTR_ERR(espi->dma_rx), "rx DMA setup failed");

		goto fail_free_page;

	}



	espi->dma_tx_data.port = EP93XX_DMA_SSP;

	espi->dma_tx_data.direction = DMA_MEM_TO_DEV;

	espi->dma_tx_data.name = "ep93xx-spi-tx";



	espi->dma_tx = dma_request_channel(mask, ep93xx_spi_dma_filter,

					   &espi->dma_tx_data);

	if (!espi->dma_tx) {

		ret = -ENODEV;

	espi->dma_tx = dma_request_chan(dev, "tx");

	if (IS_ERR(espi->dma_tx)) {

		ret = dev_err_probe(dev, PTR_ERR(espi->dma_tx), "tx DMA setup failed");

		goto fail_release_rx;

	}
@@ -647,18 +622,11 @@ static void ep93xx_spi_release_dma(struct ep93xx_spi *espi) 
static int ep93xx_spi_probe(struct platform_device *pdev)

{

	struct spi_controller *host;

	struct ep93xx_spi_info *info;

	struct ep93xx_spi *espi;

	struct resource *res;

	int irq;

	int error;



	info = dev_get_platdata(&pdev->dev);

	if (!info) {

		dev_err(&pdev->dev, "missing platform data\n");

		return -EINVAL;

	}



	irq = platform_get_irq(pdev, 0);

	if (irq < 0)

		return irq;
@@ -713,12 +681,17 @@ static int ep93xx_spi_probe(struct platform_device *pdev) 
		goto fail_release_host;

	}



	if (info->use_dma && ep93xx_spi_setup_dma(espi))

	error = ep93xx_spi_setup_dma(&pdev->dev, espi);

	if (error == -EPROBE_DEFER)

		goto fail_release_host;



	if (error)

		dev_warn(&pdev->dev, "DMA setup failed. Falling back to PIO\n");



	/* make sure that the hardware is disabled */

	writel(0, espi->mmio + SSPCR1);



	device_set_node(&host->dev, dev_fwnode(&pdev->dev));

	error = devm_spi_register_controller(&pdev->dev, host);

	if (error) {

		dev_err(&pdev->dev, "failed to register SPI host\n");
@@ -746,9 +719,16 @@ static void ep93xx_spi_remove(struct platform_device *pdev) 
	ep93xx_spi_release_dma(espi);

}



static const struct of_device_id ep93xx_spi_of_ids[] = {

	{ .compatible = "cirrus,ep9301-spi" },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, ep93xx_spi_of_ids);



static struct platform_driver ep93xx_spi_driver = {

	.driver		= {

		.name	= "ep93xx-spi",

		.of_match_table = ep93xx_spi_of_ids,

	},

	.probe		= ep93xx_spi_probe,

	.remove_new	= ep93xx_spi_remove,