drivers/mmc/host/renesas_sdhi_internal_dmac.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * DMA support for Internal DMAC with SDHI SD/SDIO controller
  *
  * Copyright (C) 2016-17 Renesas Electronics Corporation
  * Copyright (C) 2016-17 Horms Solutions, Simon Horman
  */

 #include <linux/bitops.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
 #include <linux/io-64-nonatomic-hi-lo.h>
 #include <linux/mfd/tmio.h>
 #include <linux/mmc/host.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/pagemap.h>
 #include <linux/scatterlist.h>
 #include <linux/sys_soc.h>

 #include "renesas_sdhi.h"
 #include "tmio_mmc.h"

 #define DM_CM_DTRAN_MODE	0x820
 #define DM_CM_DTRAN_CTRL	0x828
 #define DM_CM_RST		0x830
 #define DM_CM_INFO1		0x840
 #define DM_CM_INFO1_MASK	0x848
 #define DM_CM_INFO2		0x850
 #define DM_CM_INFO2_MASK	0x858
 #define DM_DTRAN_ADDR		0x880

 /* DM_CM_DTRAN_MODE */
 #define DTRAN_MODE_CH_NUM_CH0	0	/* "downstream" = for write commands */
 #define DTRAN_MODE_CH_NUM_CH1	BIT(16)	/* "upstream" = for read commands */
 #define DTRAN_MODE_BUS_WIDTH	(BIT(5) | BIT(4))
 #define DTRAN_MODE_ADDR_MODE	BIT(0)	/* 1 = Increment address */

 /* DM_CM_DTRAN_CTRL */
 #define DTRAN_CTRL_DM_START	BIT(0)

 /* DM_CM_RST */
 #define RST_DTRANRST1		BIT(9)
 #define RST_DTRANRST0		BIT(8)
 #define RST_RESERVED_BITS	GENMASK_ULL(31, 0)

 /* DM_CM_INFO1 and DM_CM_INFO1_MASK */
 #define INFO1_CLEAR		0
 #define INFO1_MASK_CLEAR	GENMASK_ULL(31, 0)
 #define INFO1_DTRANEND1		BIT(17)
 #define INFO1_DTRANEND0		BIT(16)

 /* DM_CM_INFO2 and DM_CM_INFO2_MASK */
 #define INFO2_MASK_CLEAR	GENMASK_ULL(31, 0)
 #define INFO2_DTRANERR1		BIT(17)
 #define INFO2_DTRANERR0		BIT(16)

 /*
  * Specification of this driver:
  * - host->chan_{rx,tx} will be used as a flag of enabling/disabling the dma
  * - Since this SDHI DMAC register set has 16 but 32-bit width, we
  *   need a custom accessor.
  */

 static unsigned long global_flags;
 /*
  * Workaround for avoiding to use RX DMAC by multiple channels.
  * On R-Car H3 ES1.* and M3-W ES1.0, when multiple SDHI channels use
  * RX DMAC simultaneously, sometimes hundreds of bytes data are not
  * stored into the system memory even if the DMAC interrupt happened.
  * So, this driver then uses one RX DMAC channel only.
  */
 #define SDHI_INTERNAL_DMAC_ONE_RX_ONLY	0
 #define SDHI_INTERNAL_DMAC_RX_IN_USE	1

 /* Definitions for sampling clocks */
 static struct renesas_sdhi_scc rcar_gen3_scc_taps[] = {
 	{
 		.clk_rate = 0,
 		.tap = 0x00000300,
 	},
 };

 static const struct renesas_sdhi_of_data of_rcar_r8a7795_compatible = {
 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
 			  TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2 |
 			  TMIO_MMC_HAVE_4TAP_HS400,
 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
 			  MMC_CAP_CMD23,
 	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT,
 	.bus_shift	= 2,
 	.scc_offset	= 0x1000,
 	.taps		= rcar_gen3_scc_taps,
 	.taps_num	= ARRAY_SIZE(rcar_gen3_scc_taps),
 	/* DMAC can handle 0xffffffff blk count but only 1 segment */
 	.max_blk_count	= 0xffffffff,
 	.max_segs	= 1,
 };

 static const struct renesas_sdhi_of_data of_rcar_gen3_compatible = {
 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
 			  TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2,
 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
 			  MMC_CAP_CMD23,
 	.capabilities2	= MMC_CAP2_NO_WRITE_PROTECT,
 	.bus_shift	= 2,
 	.scc_offset	= 0x1000,
 	.taps		= rcar_gen3_scc_taps,
 	.taps_num	= ARRAY_SIZE(rcar_gen3_scc_taps),
 	/* DMAC can handle 0xffffffff blk count but only 1 segment */
 	.max_blk_count	= 0xffffffff,
 	.max_segs	= 1,
 };

 static const struct of_device_id renesas_sdhi_internal_dmac_of_match[] = {
 	{ .compatible = "renesas,sdhi-mmc-r8a77470", .data = &of_rcar_gen3_compatible, },
 	{ .compatible = "renesas,sdhi-r8a7795", .data = &of_rcar_r8a7795_compatible, },
 	{ .compatible = "renesas,sdhi-r8a7796", .data = &of_rcar_r8a7795_compatible, },
 	{ .compatible = "renesas,rcar-gen3-sdhi", .data = &of_rcar_gen3_compatible, },
 	{},
 };
 MODULE_DEVICE_TABLE(of, renesas_sdhi_internal_dmac_of_match);

 static void
 renesas_sdhi_internal_dmac_dm_write(struct tmio_mmc_host *host,
 				    int addr, u64 val)
 {
 	writeq(val, host->ctl + addr);
 }

 static void
 renesas_sdhi_internal_dmac_enable_dma(struct tmio_mmc_host *host, bool enable)
 {
 	struct renesas_sdhi *priv = host_to_priv(host);

 	if (!host->chan_tx || !host->chan_rx)
 		return;

 	if (!enable)
 		renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO1,
 						    INFO1_CLEAR);

 	if (priv->dma_priv.enable)
 		priv->dma_priv.enable(host, enable);
 }

 static void
 renesas_sdhi_internal_dmac_abort_dma(struct tmio_mmc_host *host) {
 	u64 val = RST_DTRANRST1 | RST_DTRANRST0;

 	renesas_sdhi_internal_dmac_enable_dma(host, false);

 	renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST,
 					    RST_RESERVED_BITS & ~val);
 	renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST,
 					    RST_RESERVED_BITS | val);

 	clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags);

 	renesas_sdhi_internal_dmac_enable_dma(host, true);
 }

 static void
 renesas_sdhi_internal_dmac_dataend_dma(struct tmio_mmc_host *host) {
 	struct renesas_sdhi *priv = host_to_priv(host);

 	tasklet_schedule(&priv->dma_priv.dma_complete);
 }

 static void
 renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host,
 				     struct mmc_data *data)
 {
 	struct scatterlist *sg = host->sg_ptr;
 	u32 dtran_mode = DTRAN_MODE_BUS_WIDTH | DTRAN_MODE_ADDR_MODE;

 	if (!dma_map_sg(&host->pdev->dev, sg, host->sg_len,
 			mmc_get_dma_dir(data)))
 		goto force_pio;

 	/* This DMAC cannot handle if buffer is not 8-bytes alignment */
 	if (!IS_ALIGNED(sg_dma_address(sg), 8))
 		goto force_pio_with_unmap;

 	if (data->flags & MMC_DATA_READ) {
 		dtran_mode |= DTRAN_MODE_CH_NUM_CH1;
 		if (test_bit(SDHI_INTERNAL_DMAC_ONE_RX_ONLY, &global_flags) &&
 		    test_and_set_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags))
 			goto force_pio_with_unmap;
 	} else {
 		dtran_mode |= DTRAN_MODE_CH_NUM_CH0;
 	}

 	renesas_sdhi_internal_dmac_enable_dma(host, true);

 	/* set dma parameters */
 	renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_MODE,
 					    dtran_mode);
 	renesas_sdhi_internal_dmac_dm_write(host, DM_DTRAN_ADDR,
 					    sg_dma_address(sg));

 	host->dma_on = true;

 	return;

 force_pio_with_unmap:
 	dma_unmap_sg(&host->pdev->dev, sg, host->sg_len, mmc_get_dma_dir(data));

 force_pio:
 	renesas_sdhi_internal_dmac_enable_dma(host, false);
 }

 static void renesas_sdhi_internal_dmac_issue_tasklet_fn(unsigned long arg)
 {
 	struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;

 	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);

 	/* start the DMAC */
 	renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_CTRL,
 					    DTRAN_CTRL_DM_START);
 }

 static void renesas_sdhi_internal_dmac_complete_tasklet_fn(unsigned long arg)
 {
 	struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;
 	enum dma_data_direction dir;

 	spin_lock_irq(&host->lock);

 	if (!host->data)
 		goto out;

 	if (host->data->flags & MMC_DATA_READ)
 		dir = DMA_FROM_DEVICE;
 	else
 		dir = DMA_TO_DEVICE;

 	renesas_sdhi_internal_dmac_enable_dma(host, false);
 	dma_unmap_sg(&host->pdev->dev, host->sg_ptr, host->sg_len, dir);

 	if (dir == DMA_FROM_DEVICE)
 		clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags);

 	tmio_mmc_do_data_irq(host);
 out:
 	spin_unlock_irq(&host->lock);
 }

 static void
 renesas_sdhi_internal_dmac_request_dma(struct tmio_mmc_host *host,
 				       struct tmio_mmc_data *pdata)
 {
 	struct renesas_sdhi *priv = host_to_priv(host);

 	/* Disable DMAC interrupts, we don't use them */
 	renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO1_MASK,
 					    INFO1_MASK_CLEAR);
 	renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO2_MASK,
 					    INFO2_MASK_CLEAR);

 	/* Each value is set to non-zero to assume "enabling" each DMA */
 	host->chan_rx = host->chan_tx = (void *)0xdeadbeaf;

 	tasklet_init(&priv->dma_priv.dma_complete,
 		     renesas_sdhi_internal_dmac_complete_tasklet_fn,
 		     (unsigned long)host);
 	tasklet_init(&host->dma_issue,
 		     renesas_sdhi_internal_dmac_issue_tasklet_fn,
 		     (unsigned long)host);
 }

 static void
 renesas_sdhi_internal_dmac_release_dma(struct tmio_mmc_host *host)
 {
 	/* Each value is set to zero to assume "disabling" each DMA */
 	host->chan_rx = host->chan_tx = NULL;
 }

 static const struct tmio_mmc_dma_ops renesas_sdhi_internal_dmac_dma_ops = {
 	.start = renesas_sdhi_internal_dmac_start_dma,
 	.enable = renesas_sdhi_internal_dmac_enable_dma,
 	.request = renesas_sdhi_internal_dmac_request_dma,
 	.release = renesas_sdhi_internal_dmac_release_dma,
 	.abort = renesas_sdhi_internal_dmac_abort_dma,
 	.dataend = renesas_sdhi_internal_dmac_dataend_dma,
 };

 /*
  * Whitelist of specific R-Car Gen3 SoC ES versions to use this DMAC
  * implementation as others may use a different implementation.
  */
 static const struct soc_device_attribute soc_whitelist[] = {
 	/* specific ones */
 	{ .soc_id = "r8a7795", .revision = "ES1.*",
 	  .data = (void *)BIT(SDHI_INTERNAL_DMAC_ONE_RX_ONLY) },
 	{ .soc_id = "r8a7796", .revision = "ES1.0",
 	  .data = (void *)BIT(SDHI_INTERNAL_DMAC_ONE_RX_ONLY) },
 	/* generic ones */
 	{ .soc_id = "r8a774a1" },
 	{ .soc_id = "r8a77470" },
 	{ .soc_id = "r8a7795" },
 	{ .soc_id = "r8a7796" },
 	{ .soc_id = "r8a77965" },
 	{ .soc_id = "r8a77970" },
 	{ .soc_id = "r8a77980" },
 	{ .soc_id = "r8a77995" },
 	{ /* sentinel */ }
 };

 static int renesas_sdhi_internal_dmac_probe(struct platform_device *pdev)
 {
 	const struct soc_device_attribute *soc = soc_device_match(soc_whitelist);
 	struct device *dev = &pdev->dev;

 	if (!soc)
 		return -ENODEV;

 	global_flags |= (unsigned long)soc->data;

 	dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms), GFP_KERNEL);
 	if (!dev->dma_parms)
 		return -ENOMEM;

 	/* value is max of SD_SECCNT. Confirmed by HW engineers */
 	dma_set_max_seg_size(dev, 0xffffffff);

 	return renesas_sdhi_probe(pdev, &renesas_sdhi_internal_dmac_dma_ops);
 }

 static const struct dev_pm_ops renesas_sdhi_internal_dmac_dev_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 				pm_runtime_force_resume)
 	SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend,
 			   tmio_mmc_host_runtime_resume,
 			   NULL)
 };

 static struct platform_driver renesas_internal_dmac_sdhi_driver = {
 	.driver		= {
 		.name	= "renesas_sdhi_internal_dmac",
 		.pm	= &renesas_sdhi_internal_dmac_dev_pm_ops,
 		.of_match_table = renesas_sdhi_internal_dmac_of_match,
 	},
 	.probe		= renesas_sdhi_internal_dmac_probe,
 	.remove		= renesas_sdhi_remove,
 };

 module_platform_driver(renesas_internal_dmac_sdhi_driver);

 MODULE_DESCRIPTION("Renesas SDHI driver for internal DMAC");
 MODULE_AUTHOR("Yoshihiro Shimoda");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* DMA support for Internal DMAC with SDHI SD/SDIO controller
	*
	* Copyright (C) 2016-17 Renesas Electronics Corporation
	* Copyright (C) 2016-17 Horms Solutions, Simon Horman
	*/

	#include <linux/bitops.h>
	#include <linux/device.h>
	#include <linux/dma-mapping.h>
	#include <linux/io-64-nonatomic-hi-lo.h>
	#include <linux/mfd/tmio.h>
	#include <linux/mmc/host.h>
	#include <linux/mod_devicetable.h>
	#include <linux/module.h>
	#include <linux/pagemap.h>
	#include <linux/scatterlist.h>
	#include <linux/sys_soc.h>

	#include "renesas_sdhi.h"
	#include "tmio_mmc.h"

	#define DM_CM_DTRAN_MODE 0x820
	#define DM_CM_DTRAN_CTRL 0x828
	#define DM_CM_RST 0x830
	#define DM_CM_INFO1 0x840
	#define DM_CM_INFO1_MASK 0x848
	#define DM_CM_INFO2 0x850
	#define DM_CM_INFO2_MASK 0x858
	#define DM_DTRAN_ADDR 0x880

	/* DM_CM_DTRAN_MODE */
	#define DTRAN_MODE_CH_NUM_CH0 0 /* "downstream" = for write commands */
	#define DTRAN_MODE_CH_NUM_CH1 BIT(16) /* "upstream" = for read commands */
	#define DTRAN_MODE_BUS_WIDTH (BIT(5) \| BIT(4))
	#define DTRAN_MODE_ADDR_MODE BIT(0) /* 1 = Increment address */

	/* DM_CM_DTRAN_CTRL */
	#define DTRAN_CTRL_DM_START BIT(0)

	/* DM_CM_RST */
	#define RST_DTRANRST1 BIT(9)
	#define RST_DTRANRST0 BIT(8)
	#define RST_RESERVED_BITS GENMASK_ULL(31, 0)

	/* DM_CM_INFO1 and DM_CM_INFO1_MASK */
	#define INFO1_CLEAR 0
	#define INFO1_MASK_CLEAR GENMASK_ULL(31, 0)
	#define INFO1_DTRANEND1 BIT(17)
	#define INFO1_DTRANEND0 BIT(16)

	/* DM_CM_INFO2 and DM_CM_INFO2_MASK */
	#define INFO2_MASK_CLEAR GENMASK_ULL(31, 0)
	#define INFO2_DTRANERR1 BIT(17)
	#define INFO2_DTRANERR0 BIT(16)

	/*
	* Specification of this driver:
	* - host->chan_{rx,tx} will be used as a flag of enabling/disabling the dma
	* - Since this SDHI DMAC register set has 16 but 32-bit width, we
	* need a custom accessor.
	*/

	static unsigned long global_flags;
	/*
	* Workaround for avoiding to use RX DMAC by multiple channels.
	* On R-Car H3 ES1.* and M3-W ES1.0, when multiple SDHI channels use
	* RX DMAC simultaneously, sometimes hundreds of bytes data are not
	* stored into the system memory even if the DMAC interrupt happened.
	* So, this driver then uses one RX DMAC channel only.
	*/
	#define SDHI_INTERNAL_DMAC_ONE_RX_ONLY 0
	#define SDHI_INTERNAL_DMAC_RX_IN_USE 1

	/* Definitions for sampling clocks */
	static struct renesas_sdhi_scc rcar_gen3_scc_taps[] = {
	{
	.clk_rate = 0,
	.tap = 0x00000300,
	},
	};

	static const struct renesas_sdhi_of_data of_rcar_r8a7795_compatible = {
	.tmio_flags = TMIO_MMC_HAS_IDLE_WAIT \| TMIO_MMC_CLK_ACTUAL \|
	TMIO_MMC_HAVE_CBSY \| TMIO_MMC_MIN_RCAR2 \|
	TMIO_MMC_HAVE_4TAP_HS400,
	.capabilities = MMC_CAP_SD_HIGHSPEED \| MMC_CAP_SDIO_IRQ \|
	MMC_CAP_CMD23,
	.capabilities2 = MMC_CAP2_NO_WRITE_PROTECT,
	.bus_shift = 2,
	.scc_offset = 0x1000,
	.taps = rcar_gen3_scc_taps,
	.taps_num = ARRAY_SIZE(rcar_gen3_scc_taps),
	/* DMAC can handle 0xffffffff blk count but only 1 segment */
	.max_blk_count = 0xffffffff,
	.max_segs = 1,
	};

	static const struct renesas_sdhi_of_data of_rcar_gen3_compatible = {
	.tmio_flags = TMIO_MMC_HAS_IDLE_WAIT \| TMIO_MMC_CLK_ACTUAL \|
	TMIO_MMC_HAVE_CBSY \| TMIO_MMC_MIN_RCAR2,
	.capabilities = MMC_CAP_SD_HIGHSPEED \| MMC_CAP_SDIO_IRQ \|
	MMC_CAP_CMD23,
	.capabilities2 = MMC_CAP2_NO_WRITE_PROTECT,
	.bus_shift = 2,
	.scc_offset = 0x1000,
	.taps = rcar_gen3_scc_taps,
	.taps_num = ARRAY_SIZE(rcar_gen3_scc_taps),
	/* DMAC can handle 0xffffffff blk count but only 1 segment */
	.max_blk_count = 0xffffffff,
	.max_segs = 1,
	};

	static const struct of_device_id renesas_sdhi_internal_dmac_of_match[] = {
	{ .compatible = "renesas,sdhi-mmc-r8a77470", .data = &of_rcar_gen3_compatible, },
	{ .compatible = "renesas,sdhi-r8a7795", .data = &of_rcar_r8a7795_compatible, },
	{ .compatible = "renesas,sdhi-r8a7796", .data = &of_rcar_r8a7795_compatible, },
	{ .compatible = "renesas,rcar-gen3-sdhi", .data = &of_rcar_gen3_compatible, },
	{},
	};
	MODULE_DEVICE_TABLE(of, renesas_sdhi_internal_dmac_of_match);

	static void
	renesas_sdhi_internal_dmac_dm_write(struct tmio_mmc_host *host,
	int addr, u64 val)
	{
	writeq(val, host->ctl + addr);
	}

	static void
	renesas_sdhi_internal_dmac_enable_dma(struct tmio_mmc_host *host, bool enable)
	{
	struct renesas_sdhi *priv = host_to_priv(host);

	if (!host->chan_tx \|\| !host->chan_rx)
	return;

	if (!enable)
	renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO1,
	INFO1_CLEAR);

	if (priv->dma_priv.enable)
	priv->dma_priv.enable(host, enable);
	}

	static void
	renesas_sdhi_internal_dmac_abort_dma(struct tmio_mmc_host *host) {
	u64 val = RST_DTRANRST1 \| RST_DTRANRST0;

	renesas_sdhi_internal_dmac_enable_dma(host, false);

	renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST,
	RST_RESERVED_BITS & ~val);
	renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST,
	RST_RESERVED_BITS \| val);

	clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags);

	renesas_sdhi_internal_dmac_enable_dma(host, true);
	}

	static void
	renesas_sdhi_internal_dmac_dataend_dma(struct tmio_mmc_host *host) {
	struct renesas_sdhi *priv = host_to_priv(host);

	tasklet_schedule(&priv->dma_priv.dma_complete);
	}

	static void
	renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host,
	struct mmc_data *data)
	{
	struct scatterlist *sg = host->sg_ptr;
	u32 dtran_mode = DTRAN_MODE_BUS_WIDTH \| DTRAN_MODE_ADDR_MODE;

	if (!dma_map_sg(&host->pdev->dev, sg, host->sg_len,
	mmc_get_dma_dir(data)))
	goto force_pio;

	/* This DMAC cannot handle if buffer is not 8-bytes alignment */
	if (!IS_ALIGNED(sg_dma_address(sg), 8))
	goto force_pio_with_unmap;

	if (data->flags & MMC_DATA_READ) {
	dtran_mode \|= DTRAN_MODE_CH_NUM_CH1;
	if (test_bit(SDHI_INTERNAL_DMAC_ONE_RX_ONLY, &global_flags) &&
	test_and_set_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags))
	goto force_pio_with_unmap;
	} else {
	dtran_mode \|= DTRAN_MODE_CH_NUM_CH0;
	}

	renesas_sdhi_internal_dmac_enable_dma(host, true);

	/* set dma parameters */
	renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_MODE,
	dtran_mode);
	renesas_sdhi_internal_dmac_dm_write(host, DM_DTRAN_ADDR,
	sg_dma_address(sg));

	host->dma_on = true;

	return;

	force_pio_with_unmap:
	dma_unmap_sg(&host->pdev->dev, sg, host->sg_len, mmc_get_dma_dir(data));

	force_pio:
	renesas_sdhi_internal_dmac_enable_dma(host, false);
	}

	static void renesas_sdhi_internal_dmac_issue_tasklet_fn(unsigned long arg)
	{
	struct tmio_mmc_host host = (struct tmio_mmc_host )arg;

	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);

	/* start the DMAC */
	renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_CTRL,
	DTRAN_CTRL_DM_START);
	}

	static void renesas_sdhi_internal_dmac_complete_tasklet_fn(unsigned long arg)
	{
	struct tmio_mmc_host host = (struct tmio_mmc_host )arg;
	enum dma_data_direction dir;

	spin_lock_irq(&host->lock);

	if (!host->data)
	goto out;

	if (host->data->flags & MMC_DATA_READ)
	dir = DMA_FROM_DEVICE;
	else
	dir = DMA_TO_DEVICE;

	renesas_sdhi_internal_dmac_enable_dma(host, false);
	dma_unmap_sg(&host->pdev->dev, host->sg_ptr, host->sg_len, dir);

	if (dir == DMA_FROM_DEVICE)
	clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags);

	tmio_mmc_do_data_irq(host);
	out:
	spin_unlock_irq(&host->lock);
	}

	static void
	renesas_sdhi_internal_dmac_request_dma(struct tmio_mmc_host *host,
	struct tmio_mmc_data *pdata)
	{
	struct renesas_sdhi *priv = host_to_priv(host);

	/* Disable DMAC interrupts, we don't use them */
	renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO1_MASK,
	INFO1_MASK_CLEAR);
	renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO2_MASK,
	INFO2_MASK_CLEAR);

	/* Each value is set to non-zero to assume "enabling" each DMA */
	host->chan_rx = host->chan_tx = (void *)0xdeadbeaf;

	tasklet_init(&priv->dma_priv.dma_complete,
	renesas_sdhi_internal_dmac_complete_tasklet_fn,
	(unsigned long)host);
	tasklet_init(&host->dma_issue,
	renesas_sdhi_internal_dmac_issue_tasklet_fn,
	(unsigned long)host);
	}

	static void
	renesas_sdhi_internal_dmac_release_dma(struct tmio_mmc_host *host)
	{
	/* Each value is set to zero to assume "disabling" each DMA */
	host->chan_rx = host->chan_tx = NULL;
	}

	static const struct tmio_mmc_dma_ops renesas_sdhi_internal_dmac_dma_ops = {
	.start = renesas_sdhi_internal_dmac_start_dma,
	.enable = renesas_sdhi_internal_dmac_enable_dma,
	.request = renesas_sdhi_internal_dmac_request_dma,
	.release = renesas_sdhi_internal_dmac_release_dma,
	.abort = renesas_sdhi_internal_dmac_abort_dma,
	.dataend = renesas_sdhi_internal_dmac_dataend_dma,
	};

	/*
	* Whitelist of specific R-Car Gen3 SoC ES versions to use this DMAC
	* implementation as others may use a different implementation.
	*/
	static const struct soc_device_attribute soc_whitelist[] = {
	/* specific ones */
	{ .soc_id = "r8a7795", .revision = "ES1.*",
	.data = (void *)BIT(SDHI_INTERNAL_DMAC_ONE_RX_ONLY) },
	{ .soc_id = "r8a7796", .revision = "ES1.0",
	.data = (void *)BIT(SDHI_INTERNAL_DMAC_ONE_RX_ONLY) },
	/* generic ones */
	{ .soc_id = "r8a774a1" },
	{ .soc_id = "r8a77470" },
	{ .soc_id = "r8a7795" },
	{ .soc_id = "r8a7796" },
	{ .soc_id = "r8a77965" },
	{ .soc_id = "r8a77970" },
	{ .soc_id = "r8a77980" },
	{ .soc_id = "r8a77995" },
	{ /* sentinel */ }
	};

	static int renesas_sdhi_internal_dmac_probe(struct platform_device *pdev)
	{
	const struct soc_device_attribute *soc = soc_device_match(soc_whitelist);
	struct device *dev = &pdev->dev;

	if (!soc)
	return -ENODEV;

	global_flags \|= (unsigned long)soc->data;

	dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms), GFP_KERNEL);
	if (!dev->dma_parms)
	return -ENOMEM;

	/* value is max of SD_SECCNT. Confirmed by HW engineers */
	dma_set_max_seg_size(dev, 0xffffffff);

	return renesas_sdhi_probe(pdev, &renesas_sdhi_internal_dmac_dma_ops);
	}

	static const struct dev_pm_ops renesas_sdhi_internal_dmac_dev_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
	pm_runtime_force_resume)
	SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend,
	tmio_mmc_host_runtime_resume,
	NULL)
	};

	static struct platform_driver renesas_internal_dmac_sdhi_driver = {
	.driver = {
	.name = "renesas_sdhi_internal_dmac",
	.pm = &renesas_sdhi_internal_dmac_dev_pm_ops,
	.of_match_table = renesas_sdhi_internal_dmac_of_match,
	},
	.probe = renesas_sdhi_internal_dmac_probe,
	.remove = renesas_sdhi_remove,
	};

	module_platform_driver(renesas_internal_dmac_sdhi_driver);

	MODULE_DESCRIPTION("Renesas SDHI driver for internal DMAC");
	MODULE_AUTHOR("Yoshihiro Shimoda");
	MODULE_LICENSE("GPL v2");