/*
   * SuperH Mobile SDHI
   *
   * Copyright (C) 2009 Magnus Damm
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   * Based on "Compaq ASIC3 support":
   *
   * Copyright 2001 Compaq Computer Corporation.
   * Copyright 2004-2005 Phil Blundell
   * Copyright 2007-2008 OpenedHand Ltd.
   *
   * Authors: Phil Blundell <pb@handhelds.org>,
   *	    Samuel Ortiz <sameo@openedhand.com>
   *
   */
  
  #include <linux/kernel.h>
  #include <linux/clk.h>
  #include <linux/slab.h>
  #include <linux/mod_devicetable.h>
  #include <linux/module.h>
  #include <linux/of_device.h>
  #include <linux/platform_device.h>
  #include <linux/mmc/host.h>
  #include <linux/mmc/sh_mobile_sdhi.h>
  #include <linux/mfd/tmio.h>
  #include <linux/sh_dma.h>
  #include <linux/delay.h>
  
  #include "tmio_mmc.h"
  
  #define EXT_ACC           0xe4
  
  #define host_to_priv(host) container_of((host)->pdata, struct sh_mobile_sdhi, mmc_data)
  
  struct sh_mobile_sdhi_of_data {
  	unsigned long tmio_flags;
  	unsigned long capabilities;
  	unsigned long capabilities2;
  	enum dma_slave_buswidth dma_buswidth;
  	dma_addr_t dma_rx_offset;
  };
  
  static const struct sh_mobile_sdhi_of_data sh_mobile_sdhi_of_cfg[] = {
  	{
  		.tmio_flags = TMIO_MMC_HAS_IDLE_WAIT,
  	},
  };
  
  static const struct sh_mobile_sdhi_of_data of_rcar_gen1_compatible = {
  	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_WRPROTECT_DISABLE |
  			  TMIO_MMC_CLK_ACTUAL,
  	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
  };
  
  static const struct sh_mobile_sdhi_of_data of_rcar_gen2_compatible = {
  	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_WRPROTECT_DISABLE |
  			  TMIO_MMC_CLK_ACTUAL,
  	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
  	.dma_buswidth	= DMA_SLAVE_BUSWIDTH_4_BYTES,
  	.dma_rx_offset	= 0x2000,
  };
  
  static const struct of_device_id sh_mobile_sdhi_of_match[] = {
  	{ .compatible = "renesas,sdhi-shmobile" },
  	{ .compatible = "renesas,sdhi-sh7372" },
  	{ .compatible = "renesas,sdhi-sh73a0", .data = &sh_mobile_sdhi_of_cfg[0], },
  	{ .compatible = "renesas,sdhi-r8a73a4", .data = &sh_mobile_sdhi_of_cfg[0], },
  	{ .compatible = "renesas,sdhi-r8a7740", .data = &sh_mobile_sdhi_of_cfg[0], },
  	{ .compatible = "renesas,sdhi-r8a7778", .data = &of_rcar_gen1_compatible, },
  	{ .compatible = "renesas,sdhi-r8a7779", .data = &of_rcar_gen1_compatible, },
  	{ .compatible = "renesas,sdhi-r8a7790", .data = &of_rcar_gen2_compatible, },
  	{ .compatible = "renesas,sdhi-r8a7791", .data = &of_rcar_gen2_compatible, },
  	{ .compatible = "renesas,sdhi-r8a7792", .data = &of_rcar_gen2_compatible, },
  	{ .compatible = "renesas,sdhi-r8a7793", .data = &of_rcar_gen2_compatible, },
  	{ .compatible = "renesas,sdhi-r8a7794", .data = &of_rcar_gen2_compatible, },
  	{},
  };
  MODULE_DEVICE_TABLE(of, sh_mobile_sdhi_of_match);
  
  struct sh_mobile_sdhi {
  	struct clk *clk;
  	struct tmio_mmc_data mmc_data;
  	struct tmio_mmc_dma dma_priv;
  };
  
  static void sh_mobile_sdhi_sdbuf_width(struct tmio_mmc_host *host, int width)
  {
  	u32 val;
  
  	/*
  	 * see also
  	 *	sh_mobile_sdhi_of_data :: dma_buswidth
  	 */
  	switch (sd_ctrl_read16(host, CTL_VERSION)) {
  	case 0x490C:
  		val = (width == 32) ? 0x0001 : 0x0000;
  		break;
  	case 0xCB0D:
  		val = (width == 32) ? 0x0000 : 0x0001;
  		break;
  	default:
  		/* nothing to do */
  		return;
  	}
  
  	sd_ctrl_write16(host, EXT_ACC, val);
  }
  
  static int sh_mobile_sdhi_clk_enable(struct platform_device *pdev, unsigned int *f)
  {
  	struct mmc_host *mmc = platform_get_drvdata(pdev);
  	struct tmio_mmc_host *host = mmc_priv(mmc);
  	struct sh_mobile_sdhi *priv = host_to_priv(host);
  	int ret = clk_prepare_enable(priv->clk);
  	if (ret < 0)
  		return ret;
  
  	*f = clk_get_rate(priv->clk);
  
  	/* enable 16bit data access on SDBUF as default */
  	sh_mobile_sdhi_sdbuf_width(host, 16);
  
  	return 0;
  }
  
  static void sh_mobile_sdhi_clk_disable(struct platform_device *pdev)
  {
  	struct mmc_host *mmc = platform_get_drvdata(pdev);
  	struct tmio_mmc_host *host = mmc_priv(mmc);
  	struct sh_mobile_sdhi *priv = host_to_priv(host);
  	clk_disable_unprepare(priv->clk);
  }
  
  static int sh_mobile_sdhi_wait_idle(struct tmio_mmc_host *host)
  {
  	int timeout = 1000;
  
  	while (--timeout && !(sd_ctrl_read16(host, CTL_STATUS2) & (1 << 13)))
  		udelay(1);
  
  	if (!timeout) {
  		dev_warn(&host->pdev->dev, "timeout waiting for SD bus idle
  ");
  		return -EBUSY;
  	}
  
  	return 0;
  }
  
  static int sh_mobile_sdhi_write16_hook(struct tmio_mmc_host *host, int addr)
  {
  	switch (addr)
  	{
  	case CTL_SD_CMD:
  	case CTL_STOP_INTERNAL_ACTION:
  	case CTL_XFER_BLK_COUNT:
  	case CTL_SD_CARD_CLK_CTL:
  	case CTL_SD_XFER_LEN:
  	case CTL_SD_MEM_CARD_OPT:
  	case CTL_TRANSACTION_CTL:
  	case CTL_DMA_ENABLE:
  		return sh_mobile_sdhi_wait_idle(host);
  	}
  
  	return 0;
  }
  
  static int sh_mobile_sdhi_multi_io_quirk(struct mmc_card *card,
  					 unsigned int direction, int blk_size)
  {
  	/*
  	 * In Renesas controllers, when performing a
  	 * multiple block read of one or two blocks,
  	 * depending on the timing with which the
  	 * response register is read, the response
  	 * value may not be read properly.
  	 * Use single block read for this HW bug
  	 */
  	if ((direction == MMC_DATA_READ) &&
  	    blk_size == 2)
  		return 1;
  
  	return blk_size;
  }
  
  static void sh_mobile_sdhi_enable_dma(struct tmio_mmc_host *host, bool enable)
  {
  	sd_ctrl_write16(host, CTL_DMA_ENABLE, enable ? 2 : 0);
  
  	/* enable 32bit access if DMA mode if possibile */
  	sh_mobile_sdhi_sdbuf_width(host, enable ? 32 : 16);
  }
  
  static int sh_mobile_sdhi_probe(struct platform_device *pdev)
  {
  	const struct of_device_id *of_id =
  		of_match_device(sh_mobile_sdhi_of_match, &pdev->dev);
  	struct sh_mobile_sdhi *priv;
  	struct tmio_mmc_data *mmc_data;
  	struct tmio_mmc_data *mmd = pdev->dev.platform_data;
  	struct tmio_mmc_host *host;
  	struct resource *res;
  	int irq, ret, i = 0;
  	bool multiplexed_isr = true;
  	struct tmio_mmc_dma *dma_priv;
  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!res)
  		return -EINVAL;
  
  	priv = devm_kzalloc(&pdev->dev, sizeof(struct sh_mobile_sdhi), GFP_KERNEL);
  	if (priv == NULL) {
  		dev_err(&pdev->dev, "kzalloc failed
  ");
  		return -ENOMEM;
  	}
  
  	mmc_data = &priv->mmc_data;
  	dma_priv = &priv->dma_priv;
  
  	priv->clk = devm_clk_get(&pdev->dev, NULL);
  	if (IS_ERR(priv->clk)) {
  		ret = PTR_ERR(priv->clk);
  		dev_err(&pdev->dev, "cannot get clock: %d
  ", ret);
  		goto eprobe;
  	}
  
  	host = tmio_mmc_host_alloc(pdev);
  	if (!host) {
  		ret = -ENOMEM;
  		goto eprobe;
  	}
  
  	host->dma		= dma_priv;
  	host->write16_hook	= sh_mobile_sdhi_write16_hook;
  	host->clk_enable	= sh_mobile_sdhi_clk_enable;
  	host->clk_disable	= sh_mobile_sdhi_clk_disable;
  	host->multi_io_quirk	= sh_mobile_sdhi_multi_io_quirk;
  	/* SD control register space size is 0x100, 0x200 for bus_shift=1 */
  	if (resource_size(res) > 0x100)
  		host->bus_shift = 1;
  	else
  		host->bus_shift = 0;
  
  	if (mmd)
  		*mmc_data = *mmd;
  
  	dma_priv->filter = shdma_chan_filter;
  	dma_priv->enable = sh_mobile_sdhi_enable_dma;
  
  	mmc_data->alignment_shift = 1; /* 2-byte alignment */
  	mmc_data->capabilities |= MMC_CAP_MMC_HIGHSPEED;
  
  	/*
  	 * All SDHI blocks support 2-byte and larger block sizes in 4-bit
  	 * bus width mode.
  	 */
  	mmc_data->flags |= TMIO_MMC_BLKSZ_2BYTES;
  
  	/*
  	 * All SDHI blocks support SDIO IRQ signalling.
  	 */
  	mmc_data->flags |= TMIO_MMC_SDIO_IRQ;
  
  	/*
  	 * All SDHI have CMD12 controll bit
  	 */
  	mmc_data->flags |= TMIO_MMC_HAVE_CMD12_CTRL;
  
  	/*
  	 * All SDHI need SDIO_INFO1 reserved bit
  	 */
  	mmc_data->flags |= TMIO_MMC_SDIO_STATUS_QUIRK;
  
  	if (of_id && of_id->data) {
  		const struct sh_mobile_sdhi_of_data *of_data = of_id->data;
  		mmc_data->flags |= of_data->tmio_flags;
  		mmc_data->capabilities |= of_data->capabilities;
  		mmc_data->capabilities2 |= of_data->capabilities2;
  		mmc_data->dma_rx_offset = of_data->dma_rx_offset;
  		dma_priv->dma_buswidth = of_data->dma_buswidth;
  	}
  
  	ret = tmio_mmc_host_probe(host, mmc_data);
  	if (ret < 0)
  		goto efree;
  
  	/*
  	 * Allow one or more specific (named) ISRs or
  	 * one or more multiplexed (un-named) ISRs.
  	 */
  
  	irq = platform_get_irq_byname(pdev, SH_MOBILE_SDHI_IRQ_CARD_DETECT);
  	if (irq >= 0) {
  		multiplexed_isr = false;
  		ret = devm_request_irq(&pdev->dev, irq, tmio_mmc_card_detect_irq, 0,
  				  dev_name(&pdev->dev), host);
  		if (ret)
  			goto eirq;
  	}
  
  	irq = platform_get_irq_byname(pdev, SH_MOBILE_SDHI_IRQ_SDIO);
  	if (irq >= 0) {
  		multiplexed_isr = false;
  		ret = devm_request_irq(&pdev->dev, irq, tmio_mmc_sdio_irq, 0,
  				  dev_name(&pdev->dev), host);
  		if (ret)
  			goto eirq;
  	}
  
  	irq = platform_get_irq_byname(pdev, SH_MOBILE_SDHI_IRQ_SDCARD);
  	if (irq >= 0) {
  		multiplexed_isr = false;
  		ret = devm_request_irq(&pdev->dev, irq, tmio_mmc_sdcard_irq, 0,
  				  dev_name(&pdev->dev), host);
  		if (ret)
  			goto eirq;
  	} else if (!multiplexed_isr) {
  		dev_err(&pdev->dev,
  			"Principal SD-card IRQ is missing among named interrupts
  ");
  		ret = irq;
  		goto eirq;
  	}
  
  	if (multiplexed_isr) {
  		while (1) {
  			irq = platform_get_irq(pdev, i);
  			if (irq < 0)
  				break;
  			i++;
  			ret = devm_request_irq(&pdev->dev, irq, tmio_mmc_irq, 0,
  					  dev_name(&pdev->dev), host);
  			if (ret)
  				goto eirq;
  		}
  
  		/* There must be at least one IRQ source */
  		if (!i) {
  			ret = irq;
  			goto eirq;
  		}
  	}
  
  	dev_info(&pdev->dev, "%s base at 0x%08lx clock rate %u MHz
  ",
  		 mmc_hostname(host->mmc), (unsigned long)
  		 (platform_get_resource(pdev, IORESOURCE_MEM, 0)->start),
  		 host->mmc->f_max / 1000000);
  
  	return ret;
  
  eirq:
  	tmio_mmc_host_remove(host);
  efree:
  	tmio_mmc_host_free(host);
  eprobe:
  	return ret;
  }
  
  static int sh_mobile_sdhi_remove(struct platform_device *pdev)
  {
  	struct mmc_host *mmc = platform_get_drvdata(pdev);
  	struct tmio_mmc_host *host = mmc_priv(mmc);
  
  	tmio_mmc_host_remove(host);
  
  	return 0;
  }
  
  static const struct dev_pm_ops tmio_mmc_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 sh_mobile_sdhi_driver = {
  	.driver		= {
  		.name	= "sh_mobile_sdhi",
  		.pm	= &tmio_mmc_dev_pm_ops,
  		.of_match_table = sh_mobile_sdhi_of_match,
  	},
  	.probe		= sh_mobile_sdhi_probe,
  	.remove		= sh_mobile_sdhi_remove,
  };
  
  module_platform_driver(sh_mobile_sdhi_driver);
  
  MODULE_DESCRIPTION("SuperH Mobile SDHI driver");
  MODULE_AUTHOR("Magnus Damm");
  MODULE_LICENSE("GPL v2");
  MODULE_ALIAS("platform:sh_mobile_sdhi");