/*
 *  acard-ahci.c - ACard AHCI SATA support
 *
 *  Maintained by:  Jeff Garzik <jgarzik@pobox.com>
 *		    Please ALWAYS copy linux-ide@vger.kernel.org
 *		    on emails.
 *
 *  Copyright 2010 Red Hat, Inc.
 *
 *
 *  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, 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; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *
 * libata documentation is available via 'make {ps|pdf}docs',
 * as Documentation/DocBook/libata.*
 *
 * AHCI hardware documentation:
 * http://www.intel.com/technology/serialata/pdf/rev1_0.pdf
 * http://www.intel.com/technology/serialata/pdf/rev1_1.pdf
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/dma-mapping.h>
#include <linux/device.h>
#include <linux/dmi.h>
#include <linux/gfp.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_cmnd.h>
#include <linux/libata.h>
#include "ahci.h"

#define DRV_NAME	"acard-ahci"
#define DRV_VERSION	"1.0"

/*
  Received FIS structure limited to 80h.
*/

#define ACARD_AHCI_RX_FIS_SZ 128

enum {
	AHCI_PCI_BAR		= 5,
};

enum board_ids {
	board_acard_ahci,
};

struct acard_sg {
	__le32			addr;
	__le32			addr_hi;
	__le32			reserved;
	__le32			size;	 /* bit 31 (EOT) max==0x10000 (64k) */
};

static void acard_ahci_qc_prep(struct ata_queued_cmd *qc);
static bool acard_ahci_qc_fill_rtf(struct ata_queued_cmd *qc);
static int acard_ahci_port_start(struct ata_port *ap);
static int acard_ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);

#ifdef CONFIG_PM
static int acard_ahci_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg);
static int acard_ahci_pci_device_resume(struct pci_dev *pdev);
#endif

static struct scsi_host_template acard_ahci_sht = {
	AHCI_SHT("acard-ahci"),
};

static struct ata_port_operations acard_ops = {
	.inherits		= &ahci_ops,
	.qc_prep		= acard_ahci_qc_prep,
	.qc_fill_rtf		= acard_ahci_qc_fill_rtf,
	.port_start             = acard_ahci_port_start,
};

#define AHCI_HFLAGS(flags)	.private_data	= (void *)(flags)

static const struct ata_port_info acard_ahci_port_info[] = {
	[board_acard_ahci] =
	{
		AHCI_HFLAGS	(AHCI_HFLAG_NO_NCQ),
		.flags		= AHCI_FLAG_COMMON,
		.pio_mask	= ATA_PIO4,
		.udma_mask	= ATA_UDMA6,
		.port_ops	= &acard_ops,
	},
};

static const struct pci_device_id acard_ahci_pci_tbl[] = {
	/* ACard */
	{ PCI_VDEVICE(ARTOP, 0x000d), board_acard_ahci }, /* ATP8620 */

	{ }    /* terminate list */
};

static struct pci_driver acard_ahci_pci_driver = {
	.name			= DRV_NAME,
	.id_table		= acard_ahci_pci_tbl,
	.probe			= acard_ahci_init_one,
	.remove			= ata_pci_remove_one,
#ifdef CONFIG_PM
	.suspend		= acard_ahci_pci_device_suspend,
	.resume			= acard_ahci_pci_device_resume,
#endif
};

#ifdef CONFIG_PM
static int acard_ahci_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
{
	struct ata_host *host = dev_get_drvdata(&pdev->dev);
	struct ahci_host_priv *hpriv = host->private_data;
	void __iomem *mmio = hpriv->mmio;
	u32 ctl;

	if (mesg.event & PM_EVENT_SUSPEND &&
	    hpriv->flags & AHCI_HFLAG_NO_SUSPEND) {
		dev_printk(KERN_ERR, &pdev->dev,
			   "BIOS update required for suspend/resume\n");
		return -EIO;
	}

	if (mesg.event & PM_EVENT_SLEEP) {
		/* AHCI spec rev1.1 section 8.3.3:
		 * Software must disable interrupts prior to requesting a
		 * transition of the HBA to D3 state.
		 */
		ctl = readl(mmio + HOST_CTL);
		ctl &= ~HOST_IRQ_EN;
		writel(ctl, mmio + HOST_CTL);
		readl(mmio + HOST_CTL); /* flush */
	}

	return ata_pci_device_suspend(pdev, mesg);
}

static int acard_ahci_pci_device_resume(struct pci_dev *pdev)
{
	struct ata_host *host = dev_get_drvdata(&pdev->dev);
	int rc;

	rc = ata_pci_device_do_resume(pdev);
	if (rc)
		return rc;

	if (pdev->dev.power.power_state.event == PM_EVENT_SUSPEND) {
		rc = ahci_reset_controller(host);
		if (rc)
			return rc;

		ahci_init_controller(host);
	}

	ata_host_resume(host);

	return 0;
}
#endif

static int acard_ahci_configure_dma_masks(struct pci_dev *pdev, int using_dac)
{
	int rc;

	if (using_dac &&
	    !pci_set_dma_mask(pdev, DMA_BIT_MASK(64))) {
		rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
		if (rc) {
			rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
			if (rc) {
				dev_printk(KERN_ERR, &pdev->dev,
					   "64-bit DMA enable failed\n");
				return rc;
			}
		}
	} else {
		rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
		if (rc) {
			dev_printk(KERN_ERR, &pdev->dev,
				   "32-bit DMA enable failed\n");
			return rc;
		}
		rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
		if (rc) {
			dev_printk(KERN_ERR, &pdev->dev,
				   "32-bit consistent DMA enable failed\n");
			return rc;
		}
	}
	return 0;
}

static void acard_ahci_pci_print_info(struct ata_host *host)
{
	struct pci_dev *pdev = to_pci_dev(host->dev);
	u16 cc;
	const char *scc_s;

	pci_read_config_word(pdev, 0x0a, &cc);
	if (cc == PCI_CLASS_STORAGE_IDE)
		scc_s = "IDE";
	else if (cc == PCI_CLASS_STORAGE_SATA)
		scc_s = "SATA";
	else if (cc == PCI_CLASS_STORAGE_RAID)
		scc_s = "RAID";
	else
		scc_s = "unknown";

	ahci_print_info(host, scc_s);
}

static unsigned int acard_ahci_fill_sg(struct ata_queued_cmd *qc, void *cmd_tbl)
{
	struct scatterlist *sg;
	struct acard_sg *acard_sg = cmd_tbl + AHCI_CMD_TBL_HDR_SZ;
	unsigned int si, last_si = 0;

	VPRINTK("ENTER\n");

	/*
	 * Next, the S/G list.
	 */
	for_each_sg(qc->sg, sg, qc->n_elem, si) {
		dma_addr_t addr = sg_dma_address(sg);
		u32 sg_len = sg_dma_len(sg);

		/*
		 * ACard note:
		 * We must set an end-of-table (EOT) bit,
		 * and the segment cannot exceed 64k (0x10000)
		 */
		acard_sg[si].addr = cpu_to_le32(addr & 0xffffffff);
		acard_sg[si].addr_hi = cpu_to_le32((addr >> 16) >> 16);
		acard_sg[si].size = cpu_to_le32(sg_len);
		last_si = si;
	}

	acard_sg[last_si].size |= cpu_to_le32(1 << 31);	/* set EOT */

	return si;
}

static void acard_ahci_qc_prep(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	struct ahci_port_priv *pp = ap->private_data;
	int is_atapi = ata_is_atapi(qc->tf.protocol);
	void *cmd_tbl;
	u32 opts;
	const u32 cmd_fis_len = 5; /* five dwords */
	unsigned int n_elem;

	/*
	 * Fill in command table information.  First, the header,
	 * a SATA Register - Host to Device command FIS.
	 */
	cmd_tbl = pp->cmd_tbl + qc->tag * AHCI_CMD_TBL_SZ;

	ata_tf_to_fis(&qc->tf, qc->dev->link->pmp, 1, cmd_tbl);
	if (is_atapi) {
		memset(cmd_tbl + AHCI_CMD_TBL_CDB, 0, 32);
		memcpy(cmd_tbl + AHCI_CMD_TBL_CDB, qc->cdb, qc->dev->cdb_len);
	}

	n_elem = 0;
	if (qc->flags & ATA_QCFLAG_DMAMAP)
		n_elem = acard_ahci_fill_sg(qc, cmd_tbl);

	/*
	 * Fill in command slot information.
	 *
	 * ACard note: prd table length not filled in
	 */
	opts = cmd_fis_len | (qc->dev->link->pmp << 12);
	if (qc->tf.flags & ATA_TFLAG_WRITE)
		opts |= AHCI_CMD_WRITE;
	if (is_atapi)
		opts |= AHCI_CMD_ATAPI | AHCI_CMD_PREFETCH;

	ahci_fill_cmd_slot(pp, qc->tag, opts);
}

static bool acard_ahci_qc_fill_rtf(struct ata_queued_cmd *qc)
{
	struct ahci_port_priv *pp = qc->ap->private_data;
	u8 *rx_fis = pp->rx_fis;

	if (pp->fbs_enabled)
		rx_fis += qc->dev->link->pmp * ACARD_AHCI_RX_FIS_SZ;

	/*
	 * After a successful execution of an ATA PIO data-in command,
	 * the device doesn't send D2H Reg FIS to update the TF and
	 * the host should take TF and E_Status from the preceding PIO
	 * Setup FIS.
	 */
	if (qc->tf.protocol == ATA_PROT_PIO && qc->dma_dir == DMA_FROM_DEVICE &&
	    !(qc->flags & ATA_QCFLAG_FAILED)) {
		ata_tf_from_fis(rx_fis + RX_FIS_PIO_SETUP, &qc->result_tf);
		qc->result_tf.command = (rx_fis + RX_FIS_PIO_SETUP)[15];
	} else
		ata_tf_from_fis(rx_fis + RX_FIS_D2H_REG, &qc->result_tf);

	return true;
}

static int acard_ahci_port_start(struct ata_port *ap)
{
	struct ahci_host_priv *hpriv = ap->host->private_data;
	struct device *dev = ap->host->dev;
	struct ahci_port_priv *pp;
	void *mem;
	dma_addr_t mem_dma;
	size_t dma_sz, rx_fis_sz;

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

	/* check FBS capability */
	if ((hpriv->cap & HOST_CAP_FBS) && sata_pmp_supported(ap)) {
		void __iomem *port_mmio = ahci_port_base(ap);
		u32 cmd = readl(port_mmio + PORT_CMD);
		if (cmd & PORT_CMD_FBSCP)
			pp->fbs_supported = true;
		else if (hpriv->flags & AHCI_HFLAG_YES_FBS) {
			dev_printk(KERN_INFO, dev,
				   "port %d can do FBS, forcing FBSCP\n",
				   ap->port_no);
			pp->fbs_supported = true;
		} else
			dev_printk(KERN_WARNING, dev,
				   "port %d is not capable of FBS\n",
				   ap->port_no);
	}

	if (pp->fbs_supported) {
		dma_sz = AHCI_PORT_PRIV_FBS_DMA_SZ;
		rx_fis_sz = ACARD_AHCI_RX_FIS_SZ * 16;
	} else {
		dma_sz = AHCI_PORT_PRIV_DMA_SZ;
		rx_fis_sz = ACARD_AHCI_RX_FIS_SZ;
	}

	mem = dmam_alloc_coherent(dev, dma_sz, &mem_dma, GFP_KERNEL);
	if (!mem)
		return -ENOMEM;
	memset(mem, 0, dma_sz);

	/*
	 * First item in chunk of DMA memory: 32-slot command table,
	 * 32 bytes each in size
	 */
	pp->cmd_slot = mem;
	pp->cmd_slot_dma = mem_dma;

	mem += AHCI_CMD_SLOT_SZ;
	mem_dma += AHCI_CMD_SLOT_SZ;

	/*
	 * Second item: Received-FIS area
	 */
	pp->rx_fis = mem;
	pp->rx_fis_dma = mem_dma;

	mem += rx_fis_sz;
	mem_dma += rx_fis_sz;

	/*
	 * Third item: data area for storing a single command
	 * and its scatter-gather table
	 */
	pp->cmd_tbl = mem;
	pp->cmd_tbl_dma = mem_dma;

	/*
	 * Save off initial list of interrupts to be enabled.
	 * This could be changed later
	 */
	pp->intr_mask = DEF_PORT_IRQ;

	ap->private_data = pp;

	/* engage engines, captain */
	return ahci_port_resume(ap);
}

static int acard_ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
{
	static int printed_version;
	unsigned int board_id = ent->driver_data;
	struct ata_port_info pi = acard_ahci_port_info[board_id];
	const struct ata_port_info *ppi[] = { &pi, NULL };
	struct device *dev = &pdev->dev;
	struct ahci_host_priv *hpriv;
	struct ata_host *host;
	int n_ports, i, rc;

	VPRINTK("ENTER\n");

	WARN_ON((int)ATA_MAX_QUEUE > AHCI_MAX_CMDS);

	if (!printed_version++)
		dev_printk(KERN_DEBUG, &pdev->dev, "version " DRV_VERSION "\n");

	/* acquire resources */
	rc = pcim_enable_device(pdev);
	if (rc)
		return rc;

	/* AHCI controllers often implement SFF compatible interface.
	 * Grab all PCI BARs just in case.
	 */
	rc = pcim_iomap_regions_request_all(pdev, 1 << AHCI_PCI_BAR, DRV_NAME);
	if (rc == -EBUSY)
		pcim_pin_device(pdev);
	if (rc)
		return rc;

	hpriv = devm_kzalloc(dev, sizeof(*hpriv), GFP_KERNEL);
	if (!hpriv)
		return -ENOMEM;
	hpriv->flags |= (unsigned long)pi.private_data;

	if (!(hpriv->flags & AHCI_HFLAG_NO_MSI))
		pci_enable_msi(pdev);

	hpriv->mmio = pcim_iomap_table(pdev)[AHCI_PCI_BAR];

	/* save initial config */
	ahci_save_initial_config(&pdev->dev, hpriv, 0, 0);

	/* prepare host */
	if (hpriv->cap & HOST_CAP_NCQ)
		pi.flags |= ATA_FLAG_NCQ;

	if (hpriv->cap & HOST_CAP_PMP)
		pi.flags |= ATA_FLAG_PMP;

	ahci_set_em_messages(hpriv, &pi);

	/* CAP.NP sometimes indicate the index of the last enabled
	 * port, at other times, that of the last possible port, so
	 * determining the maximum port number requires looking at
	 * both CAP.NP and port_map.
	 */
	n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map));

	host = ata_host_alloc_pinfo(&pdev->dev, ppi, n_ports);
	if (!host)
		return -ENOMEM;
	host->private_data = hpriv;

	if (!(hpriv->cap & HOST_CAP_SSS) || ahci_ignore_sss)
		host->flags |= ATA_HOST_PARALLEL_SCAN;
	else
		printk(KERN_INFO "ahci: SSS flag set, parallel bus scan disabled\n");

	for (i = 0; i < host->n_ports; i++) {
		struct ata_port *ap = host->ports[i];

		ata_port_pbar_desc(ap, AHCI_PCI_BAR, -1, "abar");
		ata_port_pbar_desc(ap, AHCI_PCI_BAR,
				   0x100 + ap->port_no * 0x80, "port");

		/* set initial link pm policy */
		/*
		ap->pm_policy = NOT_AVAILABLE;
		*/
		/* disabled/not-implemented port */
		if (!(hpriv->port_map & (1 << i)))
			ap->ops = &ata_dummy_port_ops;
	}

	/* initialize adapter */
	rc = acard_ahci_configure_dma_masks(pdev, hpriv->cap & HOST_CAP_64);
	if (rc)
		return rc;

	rc = ahci_reset_controller(host);
	if (rc)
		return rc;

	ahci_init_controller(host);
	acard_ahci_pci_print_info(host);

	pci_set_master(pdev);
	return ata_host_activate(host, pdev->irq, ahci_interrupt, IRQF_SHARED,
				 &acard_ahci_sht);
}

static int __init acard_ahci_init(void)
{
	return pci_register_driver(&acard_ahci_pci_driver);
}

static void __exit acard_ahci_exit(void)
{
	pci_unregister_driver(&acard_ahci_pci_driver);
}

MODULE_AUTHOR("Jeff Garzik");
MODULE_DESCRIPTION("ACard AHCI SATA low-level driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, acard_ahci_pci_tbl);
MODULE_VERSION(DRV_VERSION);

module_init(acard_ahci_init);
module_exit(acard_ahci_exit);