drivers/ata/ahci_xgene.c - kernel/msm-4.9 - Gitiles

 /*
  * AppliedMicro X-Gene SoC SATA Host Controller Driver
  *
  * Copyright (c) 2014, Applied Micro Circuits Corporation
  * Author: Loc Ho <lho@apm.com>
  *         Tuan Phan <tphan@apm.com>
  *         Suman Tripathi <stripathi@apm.com>
  *
  * 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.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  * NOTE: PM support is not currently available.
  *
  */
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/ahci_platform.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/phy/phy.h>
 #include "ahci.h"

 /* Max # of disk per a controller */
 #define MAX_AHCI_CHN_PERCTR		2

 /* MUX CSR */
 #define SATA_ENET_CONFIG_REG		0x00000000
 #define  CFG_SATA_ENET_SELECT_MASK	0x00000001

 /* SATA core host controller CSR */
 #define SLVRDERRATTRIBUTES		0x00000000
 #define SLVWRERRATTRIBUTES		0x00000004
 #define MSTRDERRATTRIBUTES		0x00000008
 #define MSTWRERRATTRIBUTES		0x0000000c
 #define BUSCTLREG			0x00000014
 #define IOFMSTRWAUX			0x00000018
 #define INTSTATUSMASK			0x0000002c
 #define ERRINTSTATUS			0x00000030
 #define ERRINTSTATUSMASK		0x00000034

 /* SATA host AHCI CSR */
 #define PORTCFG				0x000000a4
 #define  PORTADDR_SET(dst, src) \
 		(((dst) & ~0x0000003f) | (((u32)(src)) & 0x0000003f))
 #define PORTPHY1CFG		0x000000a8
 #define PORTPHY1CFG_FRCPHYRDY_SET(dst, src) \
 		(((dst) & ~0x00100000) | (((u32)(src) << 0x14) & 0x00100000))
 #define PORTPHY2CFG			0x000000ac
 #define PORTPHY3CFG			0x000000b0
 #define PORTPHY4CFG			0x000000b4
 #define PORTPHY5CFG			0x000000b8
 #define SCTL0				0x0000012C
 #define PORTPHY5CFG_RTCHG_SET(dst, src) \
 		(((dst) & ~0xfff00000) | (((u32)(src) << 0x14) & 0xfff00000))
 #define PORTAXICFG_EN_CONTEXT_SET(dst, src) \
 		(((dst) & ~0x01000000) | (((u32)(src) << 0x18) & 0x01000000))
 #define PORTAXICFG			0x000000bc
 #define PORTAXICFG_OUTTRANS_SET(dst, src) \
 		(((dst) & ~0x00f00000) | (((u32)(src) << 0x14) & 0x00f00000))
 #define PORTRANSCFG			0x000000c8
 #define PORTRANSCFG_RXWM_SET(dst, src)		\
 		(((dst) & ~0x0000007f) | (((u32)(src)) & 0x0000007f))

 /* SATA host controller AXI CSR */
 #define INT_SLV_TMOMASK			0x00000010

 /* SATA diagnostic CSR */
 #define CFG_MEM_RAM_SHUTDOWN		0x00000070
 #define BLOCK_MEM_RDY			0x00000074

 /* Max retry for link down */
 #define MAX_LINK_DOWN_RETRY 3

 struct xgene_ahci_context {
 	struct ahci_host_priv *hpriv;
 	struct device *dev;
 	u8 last_cmd[MAX_AHCI_CHN_PERCTR]; /* tracking the last command issued*/
 	void __iomem *csr_core;		/* Core CSR address of IP */
 	void __iomem *csr_diag;		/* Diag CSR address of IP */
 	void __iomem *csr_axi;		/* AXI CSR address of IP */
 	void __iomem *csr_mux;		/* MUX CSR address of IP */
 };

 static int xgene_ahci_init_memram(struct xgene_ahci_context *ctx)
 {
 	dev_dbg(ctx->dev, "Release memory from shutdown\n");
 	writel(0x0, ctx->csr_diag + CFG_MEM_RAM_SHUTDOWN);
 	readl(ctx->csr_diag + CFG_MEM_RAM_SHUTDOWN); /* Force a barrier */
 	msleep(1);	/* reset may take up to 1ms */
 	if (readl(ctx->csr_diag + BLOCK_MEM_RDY) != 0xFFFFFFFF) {
 		dev_err(ctx->dev, "failed to release memory from shutdown\n");
 		return -ENODEV;
 	}
 	return 0;
 }

 /**
  * xgene_ahci_restart_engine - Restart the dma engine.
  * @ap : ATA port of interest
  *
  * Restarts the dma engine inside the controller.
  */
 static int xgene_ahci_restart_engine(struct ata_port *ap)
 {
 	struct ahci_host_priv *hpriv = ap->host->private_data;

 	ahci_stop_engine(ap);
 	ahci_start_fis_rx(ap);
 	hpriv->start_engine(ap);

 	return 0;
 }

 /**
  * xgene_ahci_qc_issue - Issue commands to the device
  * @qc: Command to issue
  *
  * Due to Hardware errata for IDENTIFY DEVICE command and PACKET
  * command of ATAPI protocol set, the controller cannot clear the BSY bit
  * after receiving the PIO setup FIS. This results in the DMA state machine
  * going into the CMFatalErrorUpdate state and locks up. By restarting the
  * DMA engine, it removes the controller out of lock up state.
  */
 static unsigned int xgene_ahci_qc_issue(struct ata_queued_cmd *qc)
 {
 	struct ata_port *ap = qc->ap;
 	struct ahci_host_priv *hpriv = ap->host->private_data;
 	struct xgene_ahci_context *ctx = hpriv->plat_data;
 	int rc = 0;

 	if (unlikely((ctx->last_cmd[ap->port_no] == ATA_CMD_ID_ATA) ||
 	    (ctx->last_cmd[ap->port_no] == ATA_CMD_PACKET)))
 		xgene_ahci_restart_engine(ap);

 	rc = ahci_qc_issue(qc);

 	/* Save the last command issued */
 	ctx->last_cmd[ap->port_no] = qc->tf.command;

 	return rc;
 }

 static bool xgene_ahci_is_memram_inited(struct xgene_ahci_context *ctx)
 {
 	void __iomem *diagcsr = ctx->csr_diag;

 	return (readl(diagcsr + CFG_MEM_RAM_SHUTDOWN) == 0 &&
 	        readl(diagcsr + BLOCK_MEM_RDY) == 0xFFFFFFFF);
 }

 /**
  * xgene_ahci_read_id - Read ID data from the specified device
  * @dev: device
  * @tf: proposed taskfile
  * @id: data buffer
  *
  * This custom read ID function is required due to the fact that the HW
  * does not support DEVSLP.
  */
 static unsigned int xgene_ahci_read_id(struct ata_device *dev,
 				       struct ata_taskfile *tf, u16 *id)
 {
 	u32 err_mask;

 	err_mask = ata_do_dev_read_id(dev, tf, id);
 	if (err_mask)
 		return err_mask;

 	/*
 	 * Mask reserved area. Word78 spec of Link Power Management
 	 * bit15-8: reserved
 	 * bit7: NCQ autosence
 	 * bit6: Software settings preservation supported
 	 * bit5: reserved
 	 * bit4: In-order sata delivery supported
 	 * bit3: DIPM requests supported
 	 * bit2: DMA Setup FIS Auto-Activate optimization supported
 	 * bit1: DMA Setup FIX non-Zero buffer offsets supported
 	 * bit0: Reserved
 	 *
 	 * Clear reserved bit 8 (DEVSLP bit) as we don't support DEVSLP
 	 */
 	id[ATA_ID_FEATURE_SUPP] &= cpu_to_le16(~(1 << 8));

 	return 0;
 }

 static void xgene_ahci_set_phy_cfg(struct xgene_ahci_context *ctx, int channel)
 {
 	void __iomem *mmio = ctx->hpriv->mmio;
 	u32 val;

 	dev_dbg(ctx->dev, "port configure mmio 0x%p channel %d\n",
 		mmio, channel);
 	val = readl(mmio + PORTCFG);
 	val = PORTADDR_SET(val, channel == 0 ? 2 : 3);
 	writel(val, mmio + PORTCFG);
 	readl(mmio + PORTCFG);  /* Force a barrier */
 	/* Disable fix rate */
 	writel(0x0001fffe, mmio + PORTPHY1CFG);
 	readl(mmio + PORTPHY1CFG); /* Force a barrier */
 	writel(0x28183219, mmio + PORTPHY2CFG);
 	readl(mmio + PORTPHY2CFG); /* Force a barrier */
 	writel(0x13081008, mmio + PORTPHY3CFG);
 	readl(mmio + PORTPHY3CFG); /* Force a barrier */
 	writel(0x00480815, mmio + PORTPHY4CFG);
 	readl(mmio + PORTPHY4CFG); /* Force a barrier */
 	/* Set window negotiation */
 	val = readl(mmio + PORTPHY5CFG);
 	val = PORTPHY5CFG_RTCHG_SET(val, 0x300);
 	writel(val, mmio + PORTPHY5CFG);
 	readl(mmio + PORTPHY5CFG); /* Force a barrier */
 	val = readl(mmio + PORTAXICFG);
 	val = PORTAXICFG_EN_CONTEXT_SET(val, 0x1); /* Enable context mgmt */
 	val = PORTAXICFG_OUTTRANS_SET(val, 0xe); /* Set outstanding */
 	writel(val, mmio + PORTAXICFG);
 	readl(mmio + PORTAXICFG); /* Force a barrier */
 	/* Set the watermark threshold of the receive FIFO */
 	val = readl(mmio + PORTRANSCFG);
 	val = PORTRANSCFG_RXWM_SET(val, 0x30);
 	writel(val, mmio + PORTRANSCFG);
 }

 /**
  * xgene_ahci_do_hardreset - Issue the actual COMRESET
  * @link: link to reset
  * @deadline: deadline jiffies for the operation
  * @online: Return value to indicate if device online
  *
  * Due to the limitation of the hardware PHY, a difference set of setting is
  * required for each supported disk speed - Gen3 (6.0Gbps), Gen2 (3.0Gbps),
  * and Gen1 (1.5Gbps). Otherwise during long IO stress test, the PHY will
  * report disparity error and etc. In addition, during COMRESET, there can
  * be error reported in the register PORT_SCR_ERR. For SERR_DISPARITY and
  * SERR_10B_8B_ERR, the PHY receiver line must be reseted. Also during long
  * reboot cycle regression, sometimes the PHY reports link down even if the
  * device is present because of speed negotiation failure. so need to retry
  * the COMRESET to get the link up. The following algorithm is followed to
  * proper configure the hardware PHY during COMRESET:
  *
  * Alg Part 1:
  * 1. Start the PHY at Gen3 speed (default setting)
  * 2. Issue the COMRESET
  * 3. If no link, go to Alg Part 3
  * 4. If link up, determine if the negotiated speed matches the PHY
  *    configured speed
  * 5. If they matched, go to Alg Part 2
  * 6. If they do not matched and first time, configure the PHY for the linked
  *    up disk speed and repeat step 2
  * 7. Go to Alg Part 2
  *
  * Alg Part 2:
  * 1. On link up, if there are any SERR_DISPARITY and SERR_10B_8B_ERR error
  *    reported in the register PORT_SCR_ERR, then reset the PHY receiver line
  * 2. Go to Alg Part 4
  *
  * Alg Part 3:
  * 1. Check the PORT_SCR_STAT to see whether device presence detected but PHY
  *    communication establishment failed and maximum link down attempts are
  *    less than Max attempts 3 then goto Alg Part 1.
  * 2. Go to Alg Part 4.
  *
  * Alg Part 4:
  * 1. Clear any pending from register PORT_SCR_ERR.
  *
  * NOTE: For the initial version, we will NOT support Gen1/Gen2. In addition
  *       and until the underlying PHY supports an method to reset the receiver
  *       line, on detection of SERR_DISPARITY or SERR_10B_8B_ERR errors,
  *       an warning message will be printed.
  */
 static int xgene_ahci_do_hardreset(struct ata_link *link,
 				   unsigned long deadline, bool *online)
 {
 	const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
 	struct ata_port *ap = link->ap;
 	struct ahci_host_priv *hpriv = ap->host->private_data;
 	struct xgene_ahci_context *ctx = hpriv->plat_data;
 	struct ahci_port_priv *pp = ap->private_data;
 	u8 *d2h_fis = pp->rx_fis + RX_FIS_D2H_REG;
 	void __iomem *port_mmio = ahci_port_base(ap);
 	struct ata_taskfile tf;
 	int link_down_retry = 0;
 	int rc;
 	u32 val, sstatus;

 	do {
 		/* clear D2H reception area to properly wait for D2H FIS */
 		ata_tf_init(link->device, &tf);
 		tf.command = ATA_BUSY;
 		ata_tf_to_fis(&tf, 0, 0, d2h_fis);
 		rc = sata_link_hardreset(link, timing, deadline, online,
 				 ahci_check_ready);
 		if (*online) {
 			val = readl(port_mmio + PORT_SCR_ERR);
 			if (val & (SERR_DISPARITY | SERR_10B_8B_ERR))
 				dev_warn(ctx->dev, "link has error\n");
 			break;
 		}

 		sata_scr_read(link, SCR_STATUS, &sstatus);
 	} while (link_down_retry++ < MAX_LINK_DOWN_RETRY &&
 		 (sstatus & 0xff) == 0x1);

 	/* clear all errors if any pending */
 	val = readl(port_mmio + PORT_SCR_ERR);
 	writel(val, port_mmio + PORT_SCR_ERR);

 	return rc;
 }

 static int xgene_ahci_hardreset(struct ata_link *link, unsigned int *class,
 				unsigned long deadline)
 {
 	struct ata_port *ap = link->ap;
         struct ahci_host_priv *hpriv = ap->host->private_data;
 	void __iomem *port_mmio = ahci_port_base(ap);
 	bool online;
 	int rc;
 	u32 portcmd_saved;
 	u32 portclb_saved;
 	u32 portclbhi_saved;
 	u32 portrxfis_saved;
 	u32 portrxfishi_saved;

 	/* As hardreset resets these CSR, save it to restore later */
 	portcmd_saved = readl(port_mmio + PORT_CMD);
 	portclb_saved = readl(port_mmio + PORT_LST_ADDR);
 	portclbhi_saved = readl(port_mmio + PORT_LST_ADDR_HI);
 	portrxfis_saved = readl(port_mmio + PORT_FIS_ADDR);
 	portrxfishi_saved = readl(port_mmio + PORT_FIS_ADDR_HI);

 	ahci_stop_engine(ap);

 	rc = xgene_ahci_do_hardreset(link, deadline, &online);

 	/* As controller hardreset clears them, restore them */
 	writel(portcmd_saved, port_mmio + PORT_CMD);
 	writel(portclb_saved, port_mmio + PORT_LST_ADDR);
 	writel(portclbhi_saved, port_mmio + PORT_LST_ADDR_HI);
 	writel(portrxfis_saved, port_mmio + PORT_FIS_ADDR);
 	writel(portrxfishi_saved, port_mmio + PORT_FIS_ADDR_HI);

 	hpriv->start_engine(ap);

 	if (online)
 		*class = ahci_dev_classify(ap);

 	return rc;
 }

 static void xgene_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 xgene_ahci_ops = {
 	.inherits = &ahci_ops,
 	.host_stop = xgene_ahci_host_stop,
 	.hardreset = xgene_ahci_hardreset,
 	.read_id = xgene_ahci_read_id,
 	.qc_issue = xgene_ahci_qc_issue,
 };

 static const struct ata_port_info xgene_ahci_port_info = {
 	.flags = AHCI_FLAG_COMMON,
 	.pio_mask = ATA_PIO4,
 	.udma_mask = ATA_UDMA6,
 	.port_ops = &xgene_ahci_ops,
 };

 static int xgene_ahci_hw_init(struct ahci_host_priv *hpriv)
 {
 	struct xgene_ahci_context *ctx = hpriv->plat_data;
 	int i;
 	int rc;
 	u32 val;

 	/* Remove IP RAM out of shutdown */
 	rc = xgene_ahci_init_memram(ctx);
 	if (rc)
 		return rc;

 	for (i = 0; i < MAX_AHCI_CHN_PERCTR; i++)
 		xgene_ahci_set_phy_cfg(ctx, i);

 	/* AXI disable Mask */
 	writel(0xffffffff, hpriv->mmio + HOST_IRQ_STAT);
 	readl(hpriv->mmio + HOST_IRQ_STAT); /* Force a barrier */
 	writel(0, ctx->csr_core + INTSTATUSMASK);
 	val = readl(ctx->csr_core + INTSTATUSMASK); /* Force a barrier */
 	dev_dbg(ctx->dev, "top level interrupt mask 0x%X value 0x%08X\n",
 		INTSTATUSMASK, val);

 	writel(0x0, ctx->csr_core + ERRINTSTATUSMASK);
 	readl(ctx->csr_core + ERRINTSTATUSMASK); /* Force a barrier */
 	writel(0x0, ctx->csr_axi + INT_SLV_TMOMASK);
 	readl(ctx->csr_axi + INT_SLV_TMOMASK);

 	/* Enable AXI Interrupt */
 	writel(0xffffffff, ctx->csr_core + SLVRDERRATTRIBUTES);
 	writel(0xffffffff, ctx->csr_core + SLVWRERRATTRIBUTES);
 	writel(0xffffffff, ctx->csr_core + MSTRDERRATTRIBUTES);
 	writel(0xffffffff, ctx->csr_core + MSTWRERRATTRIBUTES);

 	/* Enable coherency */
 	val = readl(ctx->csr_core + BUSCTLREG);
 	val &= ~0x00000002;     /* Enable write coherency */
 	val &= ~0x00000001;     /* Enable read coherency */
 	writel(val, ctx->csr_core + BUSCTLREG);

 	val = readl(ctx->csr_core + IOFMSTRWAUX);
 	val |= (1 << 3);        /* Enable read coherency */
 	val |= (1 << 9);        /* Enable write coherency */
 	writel(val, ctx->csr_core + IOFMSTRWAUX);
 	val = readl(ctx->csr_core + IOFMSTRWAUX);
 	dev_dbg(ctx->dev, "coherency 0x%X value 0x%08X\n",
 		IOFMSTRWAUX, val);

 	return rc;
 }

 static int xgene_ahci_mux_select(struct xgene_ahci_context *ctx)
 {
 	u32 val;

 	/* Check for optional MUX resource */
 	if (!ctx->csr_mux)
 		return 0;

 	val = readl(ctx->csr_mux + SATA_ENET_CONFIG_REG);
 	val &= ~CFG_SATA_ENET_SELECT_MASK;
 	writel(val, ctx->csr_mux + SATA_ENET_CONFIG_REG);
 	val = readl(ctx->csr_mux + SATA_ENET_CONFIG_REG);
 	return val & CFG_SATA_ENET_SELECT_MASK ? -1 : 0;
 }

 static int xgene_ahci_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct ahci_host_priv *hpriv;
 	struct xgene_ahci_context *ctx;
 	struct resource *res;
 	int rc;

 	hpriv = ahci_platform_get_resources(pdev);
 	if (IS_ERR(hpriv))
 		return PTR_ERR(hpriv);

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

 	hpriv->plat_data = ctx;
 	ctx->hpriv = hpriv;
 	ctx->dev = dev;

 	/* Retrieve the IP core resource */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 	ctx->csr_core = devm_ioremap_resource(dev, res);
 	if (IS_ERR(ctx->csr_core))
 		return PTR_ERR(ctx->csr_core);

 	/* Retrieve the IP diagnostic resource */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
 	ctx->csr_diag = devm_ioremap_resource(dev, res);
 	if (IS_ERR(ctx->csr_diag))
 		return PTR_ERR(ctx->csr_diag);

 	/* Retrieve the IP AXI resource */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
 	ctx->csr_axi = devm_ioremap_resource(dev, res);
 	if (IS_ERR(ctx->csr_axi))
 		return PTR_ERR(ctx->csr_axi);

 	/* Retrieve the optional IP mux resource */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 4);
 	if (res) {
 		void __iomem *csr = devm_ioremap_resource(dev, res);
 		if (IS_ERR(csr))
 			return PTR_ERR(csr);

 		ctx->csr_mux = csr;
 	}

 	dev_dbg(dev, "VAddr 0x%p Mmio VAddr 0x%p\n", ctx->csr_core,
 		hpriv->mmio);

 	/* Select ATA */
 	if ((rc = xgene_ahci_mux_select(ctx))) {
 		dev_err(dev, "SATA mux selection failed error %d\n", rc);
 		return -ENODEV;
 	}

 	if (xgene_ahci_is_memram_inited(ctx)) {
 		dev_info(dev, "skip clock and PHY initialization\n");
 		goto skip_clk_phy;
 	}

 	/* Due to errata, HW requires full toggle transition */
 	rc = ahci_platform_enable_clks(hpriv);
 	if (rc)
 		goto disable_resources;
 	ahci_platform_disable_clks(hpriv);

 	rc = ahci_platform_enable_resources(hpriv);
 	if (rc)
 		goto disable_resources;

 	/* Configure the host controller */
 	xgene_ahci_hw_init(hpriv);
 skip_clk_phy:
 	hpriv->flags = AHCI_HFLAG_NO_PMP | AHCI_HFLAG_NO_NCQ;

 	rc = ahci_platform_init_host(pdev, hpriv, &xgene_ahci_port_info);
 	if (rc)
 		goto disable_resources;

 	dev_dbg(dev, "X-Gene SATA host controller initialized\n");
 	return 0;

 disable_resources:
 	ahci_platform_disable_resources(hpriv);
 	return rc;
 }

 static const struct of_device_id xgene_ahci_of_match[] = {
 	{.compatible = "apm,xgene-ahci"},
 	{},
 };
 MODULE_DEVICE_TABLE(of, xgene_ahci_of_match);

 static struct platform_driver xgene_ahci_driver = {
 	.probe = xgene_ahci_probe,
 	.remove = ata_platform_remove_one,
 	.driver = {
 		.name = "xgene-ahci",
 		.of_match_table = xgene_ahci_of_match,
 	},
 };

 module_platform_driver(xgene_ahci_driver);

 MODULE_DESCRIPTION("APM X-Gene AHCI SATA driver");
 MODULE_AUTHOR("Loc Ho <lho@apm.com>");
 MODULE_LICENSE("GPL");
 MODULE_VERSION("0.4");
	/*
	* AppliedMicro X-Gene SoC SATA Host Controller Driver
	*
	* Copyright (c) 2014, Applied Micro Circuits Corporation
	* Author: Loc Ho <lho@apm.com>
	* Tuan Phan <tphan@apm.com>
	* Suman Tripathi <stripathi@apm.com>
	*
	* 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.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	*
	* NOTE: PM support is not currently available.
	*
	*/
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/ahci_platform.h>
	#include <linux/of_address.h>
	#include <linux/of_irq.h>
	#include <linux/phy/phy.h>
	#include "ahci.h"

	/* Max # of disk per a controller */
	#define MAX_AHCI_CHN_PERCTR 2

	/* MUX CSR */
	#define SATA_ENET_CONFIG_REG 0x00000000
	#define CFG_SATA_ENET_SELECT_MASK 0x00000001

	/* SATA core host controller CSR */
	#define SLVRDERRATTRIBUTES 0x00000000
	#define SLVWRERRATTRIBUTES 0x00000004
	#define MSTRDERRATTRIBUTES 0x00000008
	#define MSTWRERRATTRIBUTES 0x0000000c
	#define BUSCTLREG 0x00000014
	#define IOFMSTRWAUX 0x00000018
	#define INTSTATUSMASK 0x0000002c
	#define ERRINTSTATUS 0x00000030
	#define ERRINTSTATUSMASK 0x00000034

	/* SATA host AHCI CSR */
	#define PORTCFG 0x000000a4
	#define PORTADDR_SET(dst, src) \
	(((dst) & ~0x0000003f) \| (((u32)(src)) & 0x0000003f))
	#define PORTPHY1CFG 0x000000a8
	#define PORTPHY1CFG_FRCPHYRDY_SET(dst, src) \
	(((dst) & ~0x00100000) \| (((u32)(src) << 0x14) & 0x00100000))
	#define PORTPHY2CFG 0x000000ac
	#define PORTPHY3CFG 0x000000b0
	#define PORTPHY4CFG 0x000000b4
	#define PORTPHY5CFG 0x000000b8
	#define SCTL0 0x0000012C
	#define PORTPHY5CFG_RTCHG_SET(dst, src) \
	(((dst) & ~0xfff00000) \| (((u32)(src) << 0x14) & 0xfff00000))
	#define PORTAXICFG_EN_CONTEXT_SET(dst, src) \
	(((dst) & ~0x01000000) \| (((u32)(src) << 0x18) & 0x01000000))
	#define PORTAXICFG 0x000000bc
	#define PORTAXICFG_OUTTRANS_SET(dst, src) \
	(((dst) & ~0x00f00000) \| (((u32)(src) << 0x14) & 0x00f00000))
	#define PORTRANSCFG 0x000000c8
	#define PORTRANSCFG_RXWM_SET(dst, src) \
	(((dst) & ~0x0000007f) \| (((u32)(src)) & 0x0000007f))

	/* SATA host controller AXI CSR */
	#define INT_SLV_TMOMASK 0x00000010

	/* SATA diagnostic CSR */
	#define CFG_MEM_RAM_SHUTDOWN 0x00000070
	#define BLOCK_MEM_RDY 0x00000074

	/* Max retry for link down */
	#define MAX_LINK_DOWN_RETRY 3

	struct xgene_ahci_context {
	struct ahci_host_priv *hpriv;
	struct device *dev;
	u8 last_cmd[MAX_AHCI_CHN_PERCTR]; /* tracking the last command issued*/
	void __iomem csr_core; / Core CSR address of IP */
	void __iomem csr_diag; / Diag CSR address of IP */
	void __iomem csr_axi; / AXI CSR address of IP */
	void __iomem csr_mux; / MUX CSR address of IP */
	};

	static int xgene_ahci_init_memram(struct xgene_ahci_context *ctx)
	{
	dev_dbg(ctx->dev, "Release memory from shutdown\n");
	writel(0x0, ctx->csr_diag + CFG_MEM_RAM_SHUTDOWN);
	readl(ctx->csr_diag + CFG_MEM_RAM_SHUTDOWN); /* Force a barrier */
	msleep(1); /* reset may take up to 1ms */
	if (readl(ctx->csr_diag + BLOCK_MEM_RDY) != 0xFFFFFFFF) {
	dev_err(ctx->dev, "failed to release memory from shutdown\n");
	return -ENODEV;
	}
	return 0;
	}

	/**
	* xgene_ahci_restart_engine - Restart the dma engine.
	* @ap : ATA port of interest
	*
	* Restarts the dma engine inside the controller.
	*/
	static int xgene_ahci_restart_engine(struct ata_port *ap)
	{
	struct ahci_host_priv *hpriv = ap->host->private_data;

	ahci_stop_engine(ap);
	ahci_start_fis_rx(ap);
	hpriv->start_engine(ap);

	return 0;
	}

	/**
	* xgene_ahci_qc_issue - Issue commands to the device
	* @qc: Command to issue
	*
	* Due to Hardware errata for IDENTIFY DEVICE command and PACKET
	* command of ATAPI protocol set, the controller cannot clear the BSY bit
	* after receiving the PIO setup FIS. This results in the DMA state machine
	* going into the CMFatalErrorUpdate state and locks up. By restarting the
	* DMA engine, it removes the controller out of lock up state.
	*/
	static unsigned int xgene_ahci_qc_issue(struct ata_queued_cmd *qc)
	{
	struct ata_port *ap = qc->ap;
	struct ahci_host_priv *hpriv = ap->host->private_data;
	struct xgene_ahci_context *ctx = hpriv->plat_data;
	int rc = 0;

	if (unlikely((ctx->last_cmd[ap->port_no] == ATA_CMD_ID_ATA) \|\|
	(ctx->last_cmd[ap->port_no] == ATA_CMD_PACKET)))
	xgene_ahci_restart_engine(ap);

	rc = ahci_qc_issue(qc);

	/* Save the last command issued */
	ctx->last_cmd[ap->port_no] = qc->tf.command;

	return rc;
	}

	static bool xgene_ahci_is_memram_inited(struct xgene_ahci_context *ctx)
	{
	void __iomem *diagcsr = ctx->csr_diag;

	return (readl(diagcsr + CFG_MEM_RAM_SHUTDOWN) == 0 &&
	readl(diagcsr + BLOCK_MEM_RDY) == 0xFFFFFFFF);
	}

	/**
	* xgene_ahci_read_id - Read ID data from the specified device
	* @dev: device
	* @tf: proposed taskfile
	* @id: data buffer
	*
	* This custom read ID function is required due to the fact that the HW
	* does not support DEVSLP.
	*/
	static unsigned int xgene_ahci_read_id(struct ata_device *dev,
	struct ata_taskfile tf, u16 id)
	{
	u32 err_mask;

	err_mask = ata_do_dev_read_id(dev, tf, id);
	if (err_mask)
	return err_mask;

	/*
	* Mask reserved area. Word78 spec of Link Power Management
	* bit15-8: reserved
	* bit7: NCQ autosence
	* bit6: Software settings preservation supported
	* bit5: reserved
	* bit4: In-order sata delivery supported
	* bit3: DIPM requests supported
	* bit2: DMA Setup FIS Auto-Activate optimization supported
	* bit1: DMA Setup FIX non-Zero buffer offsets supported
	* bit0: Reserved
	*
	* Clear reserved bit 8 (DEVSLP bit) as we don't support DEVSLP
	*/
	id[ATA_ID_FEATURE_SUPP] &= cpu_to_le16(~(1 << 8));

	return 0;
	}

	static void xgene_ahci_set_phy_cfg(struct xgene_ahci_context *ctx, int channel)
	{
	void __iomem *mmio = ctx->hpriv->mmio;
	u32 val;

	dev_dbg(ctx->dev, "port configure mmio 0x%p channel %d\n",
	mmio, channel);
	val = readl(mmio + PORTCFG);
	val = PORTADDR_SET(val, channel == 0 ? 2 : 3);
	writel(val, mmio + PORTCFG);
	readl(mmio + PORTCFG); /* Force a barrier */
	/* Disable fix rate */
	writel(0x0001fffe, mmio + PORTPHY1CFG);
	readl(mmio + PORTPHY1CFG); /* Force a barrier */
	writel(0x28183219, mmio + PORTPHY2CFG);
	readl(mmio + PORTPHY2CFG); /* Force a barrier */
	writel(0x13081008, mmio + PORTPHY3CFG);
	readl(mmio + PORTPHY3CFG); /* Force a barrier */
	writel(0x00480815, mmio + PORTPHY4CFG);
	readl(mmio + PORTPHY4CFG); /* Force a barrier */
	/* Set window negotiation */
	val = readl(mmio + PORTPHY5CFG);
	val = PORTPHY5CFG_RTCHG_SET(val, 0x300);
	writel(val, mmio + PORTPHY5CFG);
	readl(mmio + PORTPHY5CFG); /* Force a barrier */
	val = readl(mmio + PORTAXICFG);
	val = PORTAXICFG_EN_CONTEXT_SET(val, 0x1); /* Enable context mgmt */
	val = PORTAXICFG_OUTTRANS_SET(val, 0xe); /* Set outstanding */
	writel(val, mmio + PORTAXICFG);
	readl(mmio + PORTAXICFG); /* Force a barrier */
	/* Set the watermark threshold of the receive FIFO */
	val = readl(mmio + PORTRANSCFG);
	val = PORTRANSCFG_RXWM_SET(val, 0x30);
	writel(val, mmio + PORTRANSCFG);
	}

	/**
	* xgene_ahci_do_hardreset - Issue the actual COMRESET
	* @link: link to reset
	* @deadline: deadline jiffies for the operation
	* @online: Return value to indicate if device online
	*
	* Due to the limitation of the hardware PHY, a difference set of setting is
	* required for each supported disk speed - Gen3 (6.0Gbps), Gen2 (3.0Gbps),
	* and Gen1 (1.5Gbps). Otherwise during long IO stress test, the PHY will
	* report disparity error and etc. In addition, during COMRESET, there can
	* be error reported in the register PORT_SCR_ERR. For SERR_DISPARITY and
	* SERR_10B_8B_ERR, the PHY receiver line must be reseted. Also during long
	* reboot cycle regression, sometimes the PHY reports link down even if the
	* device is present because of speed negotiation failure. so need to retry
	* the COMRESET to get the link up. The following algorithm is followed to
	* proper configure the hardware PHY during COMRESET:
	*
	* Alg Part 1:
	* 1. Start the PHY at Gen3 speed (default setting)
	* 2. Issue the COMRESET
	* 3. If no link, go to Alg Part 3
	* 4. If link up, determine if the negotiated speed matches the PHY
	* configured speed
	* 5. If they matched, go to Alg Part 2
	* 6. If they do not matched and first time, configure the PHY for the linked
	* up disk speed and repeat step 2
	* 7. Go to Alg Part 2
	*
	* Alg Part 2:
	* 1. On link up, if there are any SERR_DISPARITY and SERR_10B_8B_ERR error
	* reported in the register PORT_SCR_ERR, then reset the PHY receiver line
	* 2. Go to Alg Part 4
	*
	* Alg Part 3:
	* 1. Check the PORT_SCR_STAT to see whether device presence detected but PHY
	* communication establishment failed and maximum link down attempts are
	* less than Max attempts 3 then goto Alg Part 1.
	* 2. Go to Alg Part 4.
	*
	* Alg Part 4:
	* 1. Clear any pending from register PORT_SCR_ERR.
	*
	* NOTE: For the initial version, we will NOT support Gen1/Gen2. In addition
	* and until the underlying PHY supports an method to reset the receiver
	* line, on detection of SERR_DISPARITY or SERR_10B_8B_ERR errors,
	* an warning message will be printed.
	*/
	static int xgene_ahci_do_hardreset(struct ata_link *link,
	unsigned long deadline, bool *online)
	{
	const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
	struct ata_port *ap = link->ap;
	struct ahci_host_priv *hpriv = ap->host->private_data;
	struct xgene_ahci_context *ctx = hpriv->plat_data;
	struct ahci_port_priv *pp = ap->private_data;
	u8 *d2h_fis = pp->rx_fis + RX_FIS_D2H_REG;
	void __iomem *port_mmio = ahci_port_base(ap);
	struct ata_taskfile tf;
	int link_down_retry = 0;
	int rc;
	u32 val, sstatus;

	do {
	/* clear D2H reception area to properly wait for D2H FIS */
	ata_tf_init(link->device, &tf);
	tf.command = ATA_BUSY;
	ata_tf_to_fis(&tf, 0, 0, d2h_fis);
	rc = sata_link_hardreset(link, timing, deadline, online,
	ahci_check_ready);
	if (*online) {
	val = readl(port_mmio + PORT_SCR_ERR);
	if (val & (SERR_DISPARITY \| SERR_10B_8B_ERR))
	dev_warn(ctx->dev, "link has error\n");
	break;
	}

	sata_scr_read(link, SCR_STATUS, &sstatus);
	} while (link_down_retry++ < MAX_LINK_DOWN_RETRY &&
	(sstatus & 0xff) == 0x1);

	/* clear all errors if any pending */
	val = readl(port_mmio + PORT_SCR_ERR);
	writel(val, port_mmio + PORT_SCR_ERR);

	return rc;
	}

	static int xgene_ahci_hardreset(struct ata_link link, unsigned int class,
	unsigned long deadline)
	{
	struct ata_port *ap = link->ap;
	struct ahci_host_priv *hpriv = ap->host->private_data;
	void __iomem *port_mmio = ahci_port_base(ap);
	bool online;
	int rc;
	u32 portcmd_saved;
	u32 portclb_saved;
	u32 portclbhi_saved;
	u32 portrxfis_saved;
	u32 portrxfishi_saved;

	/* As hardreset resets these CSR, save it to restore later */
	portcmd_saved = readl(port_mmio + PORT_CMD);
	portclb_saved = readl(port_mmio + PORT_LST_ADDR);
	portclbhi_saved = readl(port_mmio + PORT_LST_ADDR_HI);
	portrxfis_saved = readl(port_mmio + PORT_FIS_ADDR);
	portrxfishi_saved = readl(port_mmio + PORT_FIS_ADDR_HI);

	ahci_stop_engine(ap);

	rc = xgene_ahci_do_hardreset(link, deadline, &online);

	/* As controller hardreset clears them, restore them */
	writel(portcmd_saved, port_mmio + PORT_CMD);
	writel(portclb_saved, port_mmio + PORT_LST_ADDR);
	writel(portclbhi_saved, port_mmio + PORT_LST_ADDR_HI);
	writel(portrxfis_saved, port_mmio + PORT_FIS_ADDR);
	writel(portrxfishi_saved, port_mmio + PORT_FIS_ADDR_HI);

	hpriv->start_engine(ap);

	if (online)
	*class = ahci_dev_classify(ap);

	return rc;
	}

	static void xgene_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 xgene_ahci_ops = {
	.inherits = &ahci_ops,
	.host_stop = xgene_ahci_host_stop,
	.hardreset = xgene_ahci_hardreset,
	.read_id = xgene_ahci_read_id,
	.qc_issue = xgene_ahci_qc_issue,
	};

	static const struct ata_port_info xgene_ahci_port_info = {
	.flags = AHCI_FLAG_COMMON,
	.pio_mask = ATA_PIO4,
	.udma_mask = ATA_UDMA6,
	.port_ops = &xgene_ahci_ops,
	};

	static int xgene_ahci_hw_init(struct ahci_host_priv *hpriv)
	{
	struct xgene_ahci_context *ctx = hpriv->plat_data;
	int i;
	int rc;
	u32 val;

	/* Remove IP RAM out of shutdown */
	rc = xgene_ahci_init_memram(ctx);
	if (rc)
	return rc;

	for (i = 0; i < MAX_AHCI_CHN_PERCTR; i++)
	xgene_ahci_set_phy_cfg(ctx, i);

	/* AXI disable Mask */
	writel(0xffffffff, hpriv->mmio + HOST_IRQ_STAT);
	readl(hpriv->mmio + HOST_IRQ_STAT); /* Force a barrier */
	writel(0, ctx->csr_core + INTSTATUSMASK);
	val = readl(ctx->csr_core + INTSTATUSMASK); /* Force a barrier */
	dev_dbg(ctx->dev, "top level interrupt mask 0x%X value 0x%08X\n",
	INTSTATUSMASK, val);

	writel(0x0, ctx->csr_core + ERRINTSTATUSMASK);
	readl(ctx->csr_core + ERRINTSTATUSMASK); /* Force a barrier */
	writel(0x0, ctx->csr_axi + INT_SLV_TMOMASK);
	readl(ctx->csr_axi + INT_SLV_TMOMASK);

	/* Enable AXI Interrupt */
	writel(0xffffffff, ctx->csr_core + SLVRDERRATTRIBUTES);
	writel(0xffffffff, ctx->csr_core + SLVWRERRATTRIBUTES);
	writel(0xffffffff, ctx->csr_core + MSTRDERRATTRIBUTES);
	writel(0xffffffff, ctx->csr_core + MSTWRERRATTRIBUTES);

	/* Enable coherency */
	val = readl(ctx->csr_core + BUSCTLREG);
	val &= ~0x00000002; /* Enable write coherency */
	val &= ~0x00000001; /* Enable read coherency */
	writel(val, ctx->csr_core + BUSCTLREG);

	val = readl(ctx->csr_core + IOFMSTRWAUX);
	val \|= (1 << 3); /* Enable read coherency */
	val \|= (1 << 9); /* Enable write coherency */
	writel(val, ctx->csr_core + IOFMSTRWAUX);
	val = readl(ctx->csr_core + IOFMSTRWAUX);
	dev_dbg(ctx->dev, "coherency 0x%X value 0x%08X\n",
	IOFMSTRWAUX, val);

	return rc;
	}

	static int xgene_ahci_mux_select(struct xgene_ahci_context *ctx)
	{
	u32 val;

	/* Check for optional MUX resource */
	if (!ctx->csr_mux)
	return 0;

	val = readl(ctx->csr_mux + SATA_ENET_CONFIG_REG);
	val &= ~CFG_SATA_ENET_SELECT_MASK;
	writel(val, ctx->csr_mux + SATA_ENET_CONFIG_REG);
	val = readl(ctx->csr_mux + SATA_ENET_CONFIG_REG);
	return val & CFG_SATA_ENET_SELECT_MASK ? -1 : 0;
	}

	static int xgene_ahci_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct ahci_host_priv *hpriv;
	struct xgene_ahci_context *ctx;
	struct resource *res;
	int rc;

	hpriv = ahci_platform_get_resources(pdev);
	if (IS_ERR(hpriv))
	return PTR_ERR(hpriv);

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

	hpriv->plat_data = ctx;
	ctx->hpriv = hpriv;
	ctx->dev = dev;

	/* Retrieve the IP core resource */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	ctx->csr_core = devm_ioremap_resource(dev, res);
	if (IS_ERR(ctx->csr_core))
	return PTR_ERR(ctx->csr_core);

	/* Retrieve the IP diagnostic resource */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
	ctx->csr_diag = devm_ioremap_resource(dev, res);
	if (IS_ERR(ctx->csr_diag))
	return PTR_ERR(ctx->csr_diag);

	/* Retrieve the IP AXI resource */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
	ctx->csr_axi = devm_ioremap_resource(dev, res);
	if (IS_ERR(ctx->csr_axi))
	return PTR_ERR(ctx->csr_axi);

	/* Retrieve the optional IP mux resource */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 4);
	if (res) {
	void __iomem *csr = devm_ioremap_resource(dev, res);
	if (IS_ERR(csr))
	return PTR_ERR(csr);

	ctx->csr_mux = csr;
	}

	dev_dbg(dev, "VAddr 0x%p Mmio VAddr 0x%p\n", ctx->csr_core,
	hpriv->mmio);

	/* Select ATA */
	if ((rc = xgene_ahci_mux_select(ctx))) {
	dev_err(dev, "SATA mux selection failed error %d\n", rc);
	return -ENODEV;
	}

	if (xgene_ahci_is_memram_inited(ctx)) {
	dev_info(dev, "skip clock and PHY initialization\n");
	goto skip_clk_phy;
	}

	/* Due to errata, HW requires full toggle transition */
	rc = ahci_platform_enable_clks(hpriv);
	if (rc)
	goto disable_resources;
	ahci_platform_disable_clks(hpriv);

	rc = ahci_platform_enable_resources(hpriv);
	if (rc)
	goto disable_resources;

	/* Configure the host controller */
	xgene_ahci_hw_init(hpriv);
	skip_clk_phy:
	hpriv->flags = AHCI_HFLAG_NO_PMP \| AHCI_HFLAG_NO_NCQ;

	rc = ahci_platform_init_host(pdev, hpriv, &xgene_ahci_port_info);
	if (rc)
	goto disable_resources;

	dev_dbg(dev, "X-Gene SATA host controller initialized\n");
	return 0;

	disable_resources:
	ahci_platform_disable_resources(hpriv);
	return rc;
	}

	static const struct of_device_id xgene_ahci_of_match[] = {
	{.compatible = "apm,xgene-ahci"},
	{},
	};
	MODULE_DEVICE_TABLE(of, xgene_ahci_of_match);

	static struct platform_driver xgene_ahci_driver = {
	.probe = xgene_ahci_probe,
	.remove = ata_platform_remove_one,
	.driver = {
	.name = "xgene-ahci",
	.of_match_table = xgene_ahci_of_match,
	},
	};

	module_platform_driver(xgene_ahci_driver);

	MODULE_DESCRIPTION("APM X-Gene AHCI SATA driver");
	MODULE_AUTHOR("Loc Ho <lho@apm.com>");
	MODULE_LICENSE("GPL");
	MODULE_VERSION("0.4");