// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * Broadcom SATA3 AHCI Controller Driver
   *
   * Copyright © 2009-2015 Broadcom Corporation

   */
  
  #include <linux/ahci_platform.h>
  #include <linux/compiler.h>
  #include <linux/device.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  #include <linux/io.h>
  #include <linux/kernel.h>
  #include <linux/libata.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/platform_device.h>

  #include <linux/reset.h>

  #include <linux/string.h>
  
  #include "ahci.h"
  
  #define DRV_NAME					"brcm-ahci"
  
  #define SATA_TOP_CTRL_VERSION				0x0
  #define SATA_TOP_CTRL_BUS_CTRL				0x4
   #define MMIO_ENDIAN_SHIFT				0 /* CPU->AHCI */
   #define DMADESC_ENDIAN_SHIFT				2 /* AHCI->DDR */
   #define DMADATA_ENDIAN_SHIFT				4 /* AHCI->DDR */
   #define PIODATA_ENDIAN_SHIFT				6
    #define ENDIAN_SWAP_NONE				0
    #define ENDIAN_SWAP_FULL				2

  #define SATA_TOP_CTRL_TP_CTRL				0x8
  #define SATA_TOP_CTRL_PHY_CTRL				0xc
   #define SATA_TOP_CTRL_PHY_CTRL_1			0x0
    #define SATA_TOP_CTRL_1_PHY_DEFAULT_POWER_STATE	BIT(14)
   #define SATA_TOP_CTRL_PHY_CTRL_2			0x4
    #define SATA_TOP_CTRL_2_SW_RST_MDIOREG		BIT(0)
    #define SATA_TOP_CTRL_2_SW_RST_OOB			BIT(1)
    #define SATA_TOP_CTRL_2_SW_RST_RX			BIT(2)
    #define SATA_TOP_CTRL_2_SW_RST_TX			BIT(3)
    #define SATA_TOP_CTRL_2_PHY_GLOBAL_RESET		BIT(14)
   #define SATA_TOP_CTRL_PHY_OFFS				0x8
   #define SATA_TOP_MAX_PHYS				2

  #define SATA_FIRST_PORT_CTRL				0x700
  #define SATA_NEXT_PORT_CTRL_OFFSET			0x80
  #define SATA_PORT_PCTRL6(reg_base)			(reg_base + 0x18)

  /* On big-endian MIPS, buses are reversed to big endian, so switch them back */
  #if defined(CONFIG_MIPS) && defined(__BIG_ENDIAN)
  #define DATA_ENDIAN			 2 /* AHCI->DDR inbound accesses */
  #define MMIO_ENDIAN			 2 /* CPU->AHCI outbound accesses */
  #else
  #define DATA_ENDIAN			 0
  #define MMIO_ENDIAN			 0
  #endif
  
  #define BUS_CTRL_ENDIAN_CONF				\
  	((DATA_ENDIAN << DMADATA_ENDIAN_SHIFT) |	\
  	(DATA_ENDIAN << DMADESC_ENDIAN_SHIFT) |		\
  	(MMIO_ENDIAN << MMIO_ENDIAN_SHIFT))

  #define BUS_CTRL_ENDIAN_NSP_CONF			\
  	(0x02 << DMADATA_ENDIAN_SHIFT | 0x02 << DMADESC_ENDIAN_SHIFT)
  
  #define BUS_CTRL_ENDIAN_CONF_MASK			\
  	(0x3 << MMIO_ENDIAN_SHIFT | 0x3 << DMADESC_ENDIAN_SHIFT |	\
  	 0x3 << DMADATA_ENDIAN_SHIFT | 0x3 << PIODATA_ENDIAN_SHIFT)

  enum brcm_ahci_version {
  	BRCM_SATA_BCM7425 = 1,
  	BRCM_SATA_BCM7445,
  	BRCM_SATA_NSP,

  	BRCM_SATA_BCM7216,

  };

  enum brcm_ahci_quirks {

  	BRCM_AHCI_QUIRK_SKIP_PHY_ENABLE	= BIT(0),

  };

  struct brcm_ahci_priv {
  	struct device *dev;
  	void __iomem *top_ctrl;
  	u32 port_mask;

  	u32 quirks;

  	enum brcm_ahci_version version;

  	struct reset_control *rcdev;

  };

  static inline u32 brcm_sata_readreg(void __iomem *addr)
  {
  	/*
  	 * MIPS endianness is configured by boot strap, which also reverses all
  	 * bus endianness (i.e., big-endian CPU + big endian bus ==> native
  	 * endian I/O).
  	 *
  	 * Other architectures (e.g., ARM) either do not support big endian, or
  	 * else leave I/O in little endian mode.
  	 */

  	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))

  		return __raw_readl(addr);
  	else
  		return readl_relaxed(addr);
  }
  
  static inline void brcm_sata_writereg(u32 val, void __iomem *addr)
  {
  	/* See brcm_sata_readreg() comments */

  	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))

  		__raw_writel(val, addr);
  	else
  		writel_relaxed(val, addr);
  }

  static void brcm_sata_alpm_init(struct ahci_host_priv *hpriv)
  {
  	struct brcm_ahci_priv *priv = hpriv->plat_data;

  	u32 port_ctrl, host_caps;

  	int i;
  
  	/* Enable support for ALPM */

  	host_caps = readl(hpriv->mmio + HOST_CAP);

  	if (!(host_caps & HOST_CAP_ALPM))
  		hpriv->flags |= AHCI_HFLAG_YES_ALPM;

  
  	/*
  	 * Adjust timeout to allow PLL sufficient time to lock while waking
  	 * up from slumber mode.
  	 */
  	for (i = 0, port_ctrl = SATA_FIRST_PORT_CTRL;
  	     i < SATA_TOP_MAX_PHYS;
  	     i++, port_ctrl += SATA_NEXT_PORT_CTRL_OFFSET) {
  		if (priv->port_mask & BIT(i))
  			writel(0xff1003fc,
  			       hpriv->mmio + SATA_PORT_PCTRL6(port_ctrl));
  	}
  }

  static void brcm_sata_phy_enable(struct brcm_ahci_priv *priv, int port)
  {
  	void __iomem *phyctrl = priv->top_ctrl + SATA_TOP_CTRL_PHY_CTRL +
  				(port * SATA_TOP_CTRL_PHY_OFFS);
  	void __iomem *p;
  	u32 reg;

  	if (priv->quirks & BRCM_AHCI_QUIRK_SKIP_PHY_ENABLE)
  		return;

  	/* clear PHY_DEFAULT_POWER_STATE */
  	p = phyctrl + SATA_TOP_CTRL_PHY_CTRL_1;
  	reg = brcm_sata_readreg(p);
  	reg &= ~SATA_TOP_CTRL_1_PHY_DEFAULT_POWER_STATE;
  	brcm_sata_writereg(reg, p);
  
  	/* reset the PHY digital logic */
  	p = phyctrl + SATA_TOP_CTRL_PHY_CTRL_2;
  	reg = brcm_sata_readreg(p);
  	reg &= ~(SATA_TOP_CTRL_2_SW_RST_MDIOREG | SATA_TOP_CTRL_2_SW_RST_OOB |
  		 SATA_TOP_CTRL_2_SW_RST_RX);
  	reg |= SATA_TOP_CTRL_2_SW_RST_TX;
  	brcm_sata_writereg(reg, p);
  	reg = brcm_sata_readreg(p);
  	reg |= SATA_TOP_CTRL_2_PHY_GLOBAL_RESET;
  	brcm_sata_writereg(reg, p);
  	reg = brcm_sata_readreg(p);
  	reg &= ~SATA_TOP_CTRL_2_PHY_GLOBAL_RESET;
  	brcm_sata_writereg(reg, p);
  	(void)brcm_sata_readreg(p);
  }
  
  static void brcm_sata_phy_disable(struct brcm_ahci_priv *priv, int port)
  {
  	void __iomem *phyctrl = priv->top_ctrl + SATA_TOP_CTRL_PHY_CTRL +
  				(port * SATA_TOP_CTRL_PHY_OFFS);
  	void __iomem *p;
  	u32 reg;

  	if (priv->quirks & BRCM_AHCI_QUIRK_SKIP_PHY_ENABLE)
  		return;

  	/* power-off the PHY digital logic */
  	p = phyctrl + SATA_TOP_CTRL_PHY_CTRL_2;
  	reg = brcm_sata_readreg(p);
  	reg |= (SATA_TOP_CTRL_2_SW_RST_MDIOREG | SATA_TOP_CTRL_2_SW_RST_OOB |
  		SATA_TOP_CTRL_2_SW_RST_RX | SATA_TOP_CTRL_2_SW_RST_TX |
  		SATA_TOP_CTRL_2_PHY_GLOBAL_RESET);
  	brcm_sata_writereg(reg, p);
  
  	/* set PHY_DEFAULT_POWER_STATE */
  	p = phyctrl + SATA_TOP_CTRL_PHY_CTRL_1;
  	reg = brcm_sata_readreg(p);
  	reg |= SATA_TOP_CTRL_1_PHY_DEFAULT_POWER_STATE;
  	brcm_sata_writereg(reg, p);
  }
  
  static void brcm_sata_phys_enable(struct brcm_ahci_priv *priv)
  {
  	int i;
  
  	for (i = 0; i < SATA_TOP_MAX_PHYS; i++)
  		if (priv->port_mask & BIT(i))
  			brcm_sata_phy_enable(priv, i);
  }
  
  static void brcm_sata_phys_disable(struct brcm_ahci_priv *priv)
  {
  	int i;
  
  	for (i = 0; i < SATA_TOP_MAX_PHYS; i++)
  		if (priv->port_mask & BIT(i))
  			brcm_sata_phy_disable(priv, i);
  }

  static u32 brcm_ahci_get_portmask(struct ahci_host_priv *hpriv,

  				  struct brcm_ahci_priv *priv)
  {

  	u32 impl;

  	impl = readl(hpriv->mmio + HOST_PORTS_IMPL);

  
  	if (fls(impl) > SATA_TOP_MAX_PHYS)
  		dev_warn(priv->dev, "warning: more ports than PHYs (%#x)
  ",
  			 impl);
  	else if (!impl)
  		dev_info(priv->dev, "no ports found
  ");

  	return impl;
  }
  
  static void brcm_sata_init(struct brcm_ahci_priv *priv)
  {

  	void __iomem *ctrl = priv->top_ctrl + SATA_TOP_CTRL_BUS_CTRL;

  	u32 data;

  	/* Configure endianness */

  	data = brcm_sata_readreg(ctrl);
  	data &= ~BUS_CTRL_ENDIAN_CONF_MASK;
  	if (priv->version == BRCM_SATA_NSP)
  		data |= BUS_CTRL_ENDIAN_NSP_CONF;
  	else
  		data |= BUS_CTRL_ENDIAN_CONF;
  	brcm_sata_writereg(data, ctrl);

  }

  static unsigned int brcm_ahci_read_id(struct ata_device *dev,
  				      struct ata_taskfile *tf, u16 *id)
  {
  	struct ata_port *ap = dev->link->ap;
  	struct ata_host *host = ap->host;
  	struct ahci_host_priv *hpriv = host->private_data;
  	struct brcm_ahci_priv *priv = hpriv->plat_data;
  	void __iomem *mmio = hpriv->mmio;
  	unsigned int err_mask;
  	unsigned long flags;
  	int i, rc;
  	u32 ctl;
  
  	/* Try to read the device ID and, if this fails, proceed with the
  	 * recovery sequence below
  	 */
  	err_mask = ata_do_dev_read_id(dev, tf, id);
  	if (likely(!err_mask))
  		return err_mask;
  
  	/* Disable host interrupts */
  	spin_lock_irqsave(&host->lock, flags);
  	ctl = readl(mmio + HOST_CTL);
  	ctl &= ~HOST_IRQ_EN;
  	writel(ctl, mmio + HOST_CTL);
  	readl(mmio + HOST_CTL); /* flush */
  	spin_unlock_irqrestore(&host->lock, flags);
  
  	/* Perform the SATA PHY reset sequence */
  	brcm_sata_phy_disable(priv, ap->port_no);

  	/* Reset the SATA clock */
  	ahci_platform_disable_clks(hpriv);
  	msleep(10);
  
  	ahci_platform_enable_clks(hpriv);
  	msleep(10);

  	/* Bring the PHY back on */
  	brcm_sata_phy_enable(priv, ap->port_no);
  
  	/* Re-initialize and calibrate the PHY */
  	for (i = 0; i < hpriv->nports; i++) {
  		rc = phy_init(hpriv->phys[i]);
  		if (rc)
  			goto disable_phys;
  
  		rc = phy_calibrate(hpriv->phys[i]);
  		if (rc) {
  			phy_exit(hpriv->phys[i]);
  			goto disable_phys;
  		}
  	}
  
  	/* Re-enable host interrupts */
  	spin_lock_irqsave(&host->lock, flags);
  	ctl = readl(mmio + HOST_CTL);
  	ctl |= HOST_IRQ_EN;
  	writel(ctl, mmio + HOST_CTL);
  	readl(mmio + HOST_CTL); /* flush */
  	spin_unlock_irqrestore(&host->lock, flags);
  
  	return ata_do_dev_read_id(dev, tf, id);
  
  disable_phys:
  	while (--i >= 0) {
  		phy_power_off(hpriv->phys[i]);
  		phy_exit(hpriv->phys[i]);
  	}
  
  	return AC_ERR_OTHER;
  }
  
  static void brcm_ahci_host_stop(struct ata_host *host)
  {
  	struct ahci_host_priv *hpriv = host->private_data;
  
  	ahci_platform_disable_resources(hpriv);
  }
  
  static struct ata_port_operations ahci_brcm_platform_ops = {
  	.inherits	= &ahci_ops,
  	.host_stop	= brcm_ahci_host_stop,
  	.read_id	= brcm_ahci_read_id,
  };
  
  static const struct ata_port_info ahci_brcm_port_info = {
  	.flags		= AHCI_FLAG_COMMON | ATA_FLAG_NO_DIPM,
  	.link_flags	= ATA_LFLAG_NO_DB_DELAY,
  	.pio_mask	= ATA_PIO4,
  	.udma_mask	= ATA_UDMA6,
  	.port_ops	= &ahci_brcm_platform_ops,
  };

  static int brcm_ahci_suspend(struct device *dev)
  {
  	struct ata_host *host = dev_get_drvdata(dev);
  	struct ahci_host_priv *hpriv = host->private_data;
  	struct brcm_ahci_priv *priv = hpriv->plat_data;

  	int ret;

  	brcm_sata_phys_disable(priv);

  	if (IS_ENABLED(CONFIG_PM_SLEEP))
  		ret = ahci_platform_suspend(dev);
  	else
  		ret = 0;

  	if (priv->version != BRCM_SATA_BCM7216)
  		reset_control_assert(priv->rcdev);

  
  	return ret;

  }

  static int __maybe_unused brcm_ahci_resume(struct device *dev)

  {
  	struct ata_host *host = dev_get_drvdata(dev);
  	struct ahci_host_priv *hpriv = host->private_data;
  	struct brcm_ahci_priv *priv = hpriv->plat_data;

  	int ret = 0;

  	if (priv->version == BRCM_SATA_BCM7216)
  		ret = reset_control_reset(priv->rcdev);
  	else
  		ret = reset_control_deassert(priv->rcdev);

  	if (ret)
  		return ret;

  
  	/* Make sure clocks are turned on before re-configuration */
  	ret = ahci_platform_enable_clks(hpriv);
  	if (ret)
  		return ret;

  
  	brcm_sata_init(priv);
  	brcm_sata_phys_enable(priv);

  	brcm_sata_alpm_init(hpriv);

  
  	/* Since we had to enable clocks earlier on, we cannot use
  	 * ahci_platform_resume() as-is since a second call to
  	 * ahci_platform_enable_resources() would bump up the resources
  	 * (regulators, clocks, PHYs) count artificially so we copy the part
  	 * after ahci_platform_enable_resources().
  	 */
  	ret = ahci_platform_enable_phys(hpriv);
  	if (ret)
  		goto out_disable_phys;
  
  	ret = ahci_platform_resume_host(dev);
  	if (ret)
  		goto out_disable_platform_phys;
  
  	/* We resumed so update PM runtime state */
  	pm_runtime_disable(dev);
  	pm_runtime_set_active(dev);
  	pm_runtime_enable(dev);
  
  	return 0;
  
  out_disable_platform_phys:
  	ahci_platform_disable_phys(hpriv);
  out_disable_phys:
  	brcm_sata_phys_disable(priv);
  	ahci_platform_disable_clks(hpriv);
  	return ret;

  }
  
  static struct scsi_host_template ahci_platform_sht = {
  	AHCI_SHT(DRV_NAME),
  };

  static const struct of_device_id ahci_of_match[] = {
  	{.compatible = "brcm,bcm7425-ahci", .data = (void *)BRCM_SATA_BCM7425},
  	{.compatible = "brcm,bcm7445-ahci", .data = (void *)BRCM_SATA_BCM7445},

  	{.compatible = "brcm,bcm63138-ahci", .data = (void *)BRCM_SATA_BCM7445},

  	{.compatible = "brcm,bcm-nsp-ahci", .data = (void *)BRCM_SATA_NSP},

  	{.compatible = "brcm,bcm7216-ahci", .data = (void *)BRCM_SATA_BCM7216},

  	{},
  };
  MODULE_DEVICE_TABLE(of, ahci_of_match);

  static int brcm_ahci_probe(struct platform_device *pdev)
  {

  	const struct of_device_id *of_id;

  	struct device *dev = &pdev->dev;

  	const char *reset_name = NULL;

  	struct brcm_ahci_priv *priv;
  	struct ahci_host_priv *hpriv;
  	struct resource *res;
  	int ret;
  
  	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  	if (!priv)
  		return -ENOMEM;

  
  	of_id = of_match_node(ahci_of_match, pdev->dev.of_node);
  	if (!of_id)
  		return -ENODEV;
  
  	priv->version = (enum brcm_ahci_version)of_id->data;

  	priv->dev = dev;
  
  	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "top-ctrl");
  	priv->top_ctrl = devm_ioremap_resource(dev, res);
  	if (IS_ERR(priv->top_ctrl))
  		return PTR_ERR(priv->top_ctrl);

  	/* Reset is optional depending on platform and named differently */
  	if (priv->version == BRCM_SATA_BCM7216)
  		reset_name = "rescal";
  	else
  		reset_name = "ahci";

  	priv->rcdev = devm_reset_control_get_optional(&pdev->dev, reset_name);
  	if (IS_ERR(priv->rcdev))
  		return PTR_ERR(priv->rcdev);

  	hpriv = ahci_platform_get_resources(pdev, 0);

  	if (IS_ERR(hpriv))
  		return PTR_ERR(hpriv);

  	hpriv->plat_data = priv;
  	hpriv->flags = AHCI_HFLAG_WAKE_BEFORE_STOP | AHCI_HFLAG_NO_WRITE_TO_RO;
  
  	switch (priv->version) {
  	case BRCM_SATA_BCM7425:
  		hpriv->flags |= AHCI_HFLAG_DELAY_ENGINE;

  		fallthrough;

  	case BRCM_SATA_NSP:
  		hpriv->flags |= AHCI_HFLAG_NO_NCQ;
  		priv->quirks |= BRCM_AHCI_QUIRK_SKIP_PHY_ENABLE;
  		break;
  	default:
  		break;
  	}

  	if (priv->version == BRCM_SATA_BCM7216)
  		ret = reset_control_reset(priv->rcdev);
  	else
  		ret = reset_control_deassert(priv->rcdev);

  	if (ret)
  		return ret;

  	ret = ahci_platform_enable_clks(hpriv);
  	if (ret)
  		goto out_reset;
  
  	/* Must be first so as to configure endianness including that
  	 * of the standard AHCI register space.
  	 */

  	brcm_sata_init(priv);

  	/* Initializes priv->port_mask which is used below */
  	priv->port_mask = brcm_ahci_get_portmask(hpriv, priv);
  	if (!priv->port_mask) {
  		ret = -ENODEV;
  		goto out_disable_clks;
  	}

  	/* Must be done before ahci_platform_enable_phys() */

  	brcm_sata_phys_enable(priv);

  	brcm_sata_alpm_init(hpriv);

  	ret = ahci_platform_enable_phys(hpriv);
  	if (ret)
  		goto out_disable_phys;

  	ret = ahci_platform_init_host(pdev, hpriv, &ahci_brcm_port_info,
  				      &ahci_platform_sht);
  	if (ret)

  		goto out_disable_platform_phys;

  
  	dev_info(dev, "Broadcom AHCI SATA3 registered
  ");
  
  	return 0;

  
  out_disable_platform_phys:
  	ahci_platform_disable_phys(hpriv);
  out_disable_phys:
  	brcm_sata_phys_disable(priv);
  out_disable_clks:
  	ahci_platform_disable_clks(hpriv);
  out_reset:

  	if (priv->version != BRCM_SATA_BCM7216)
  		reset_control_assert(priv->rcdev);

  	return ret;

  }
  
  static int brcm_ahci_remove(struct platform_device *pdev)
  {
  	struct ata_host *host = dev_get_drvdata(&pdev->dev);
  	struct ahci_host_priv *hpriv = host->private_data;
  	struct brcm_ahci_priv *priv = hpriv->plat_data;
  	int ret;

  	brcm_sata_phys_disable(priv);

  	ret = ata_platform_remove_one(pdev);
  	if (ret)
  		return ret;

  	return 0;
  }

  static void brcm_ahci_shutdown(struct platform_device *pdev)
  {
  	int ret;
  
  	/* All resources releasing happens via devres, but our device, unlike a
  	 * proper remove is not disappearing, therefore using
  	 * brcm_ahci_suspend() here which does explicit power management is
  	 * appropriate.
  	 */
  	ret = brcm_ahci_suspend(&pdev->dev);
  	if (ret)
  		dev_err(&pdev->dev, "failed to shutdown
  ");
  }

  static SIMPLE_DEV_PM_OPS(ahci_brcm_pm_ops, brcm_ahci_suspend, brcm_ahci_resume);
  
  static struct platform_driver brcm_ahci_driver = {
  	.probe = brcm_ahci_probe,
  	.remove = brcm_ahci_remove,

  	.shutdown = brcm_ahci_shutdown,

  	.driver = {
  		.name = DRV_NAME,
  		.of_match_table = ahci_of_match,
  		.pm = &ahci_brcm_pm_ops,
  	},
  };
  module_platform_driver(brcm_ahci_driver);
  
  MODULE_DESCRIPTION("Broadcom SATA3 AHCI Controller Driver");
  MODULE_AUTHOR("Brian Norris");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:sata-brcmstb");